/*
 * http://www.cascoda.com/products/ca-821x/
 * Copyright (c) 2016, Cascoda, Ltd.
 * All rights reserved.
 *
 * This code is dual-licensed under both GPLv2 and 3-clause BSD. What follows is
 * the license notice for both respectively.
 *
 *******************************************************************************
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 *******************************************************************************
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 *
 * 3. Neither the name of the copyright holder nor the names of its contributors
 * may be used to endorse or promote products derived from this software without
 * specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <linux/cdev.h>
#include <linux/clk-provider.h>
#include <linux/debugfs.h>
#include <linux/delay.h>
#include <linux/gpio.h>
#include <linux/ieee802154.h>
#include <linux/io.h>
#include <linux/kfifo.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_gpio.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/poll.h>
#include <linux/skbuff.h>
#include <linux/slab.h>
#include <linux/spi/spi.h>
#include <linux/spinlock.h>
#include <linux/string.h>
#include <linux/workqueue.h>
#include <linux/interrupt.h>

#include <net/ieee802154_netdev.h>
#include <net/mac802154.h>

#define DRIVER_NAME "ca8210"

/* external clock frequencies */
#define ONE_MHZ      1000000
#define TWO_MHZ      (2 * ONE_MHZ)
#define FOUR_MHZ     (4 * ONE_MHZ)
#define EIGHT_MHZ    (8 * ONE_MHZ)
#define SIXTEEN_MHZ  (16 * ONE_MHZ)

/* spi constants */
#define CA8210_SPI_BUF_SIZE 256
#define CA8210_SYNC_TIMEOUT 1000     /* Timeout for synchronous commands [ms] */

/* test interface constants */
#define CA8210_TEST_INT_FILE_NAME "ca8210_test"
#define CA8210_TEST_INT_FIFO_SIZE 256

/* MAC status enumerations */
#define MAC_SUCCESS                     (0x00)
#define MAC_ERROR                       (0x01)
#define MAC_CANCELLED                   (0x02)
#define MAC_READY_FOR_POLL              (0x03)
#define MAC_COUNTER_ERROR               (0xDB)
#define MAC_IMPROPER_KEY_TYPE           (0xDC)
#define MAC_IMPROPER_SECURITY_LEVEL     (0xDD)
#define MAC_UNSUPPORTED_LEGACY          (0xDE)
#define MAC_UNSUPPORTED_SECURITY        (0xDF)
#define MAC_BEACON_LOST                 (0xE0)
#define MAC_CHANNEL_ACCESS_FAILURE      (0xE1)
#define MAC_DENIED                      (0xE2)
#define MAC_DISABLE_TRX_FAILURE         (0xE3)
#define MAC_SECURITY_ERROR              (0xE4)
#define MAC_FRAME_TOO_LONG              (0xE5)
#define MAC_INVALID_GTS                 (0xE6)
#define MAC_INVALID_HANDLE              (0xE7)
#define MAC_INVALID_PARAMETER           (0xE8)
#define MAC_NO_ACK                      (0xE9)
#define MAC_NO_BEACON                   (0xEA)
#define MAC_NO_DATA                     (0xEB)
#define MAC_NO_SHORT_ADDRESS            (0xEC)
#define MAC_OUT_OF_CAP                  (0xED)
#define MAC_PAN_ID_CONFLICT             (0xEE)
#define MAC_REALIGNMENT                 (0xEF)
#define MAC_TRANSACTION_EXPIRED         (0xF0)
#define MAC_TRANSACTION_OVERFLOW        (0xF1)
#define MAC_TX_ACTIVE                   (0xF2)
#define MAC_UNAVAILABLE_KEY             (0xF3)
#define MAC_UNSUPPORTED_ATTRIBUTE       (0xF4)
#define MAC_INVALID_ADDRESS             (0xF5)
#define MAC_ON_TIME_TOO_LONG            (0xF6)
#define MAC_PAST_TIME                   (0xF7)
#define MAC_TRACKING_OFF                (0xF8)
#define MAC_INVALID_INDEX               (0xF9)
#define MAC_LIMIT_REACHED               (0xFA)
#define MAC_READ_ONLY                   (0xFB)
#define MAC_SCAN_IN_PROGRESS            (0xFC)
#define MAC_SUPERFRAME_OVERLAP          (0xFD)
#define MAC_SYSTEM_ERROR                (0xFF)

/* HWME attribute IDs */
#define HWME_EDTHRESHOLD       (0x04)
#define HWME_EDVALUE           (0x06)
#define HWME_SYSCLKOUT         (0x0F)
#define HWME_LQILIMIT          (0x11)

/* TDME attribute IDs */
#define TDME_CHANNEL          (0x00)
#define TDME_ATM_CONFIG       (0x06)

#define MAX_HWME_ATTRIBUTE_SIZE  16
#define MAX_TDME_ATTRIBUTE_SIZE  2

/* PHY/MAC PIB Attribute Enumerations */
#define PHY_CURRENT_CHANNEL               (0x00)
#define PHY_TRANSMIT_POWER                (0x02)
#define PHY_CCA_MODE                      (0x03)
#define MAC_ASSOCIATION_PERMIT            (0x41)
#define MAC_AUTO_REQUEST                  (0x42)
#define MAC_BATT_LIFE_EXT                 (0x43)
#define MAC_BATT_LIFE_EXT_PERIODS         (0x44)
#define MAC_BEACON_PAYLOAD                (0x45)
#define MAC_BEACON_PAYLOAD_LENGTH         (0x46)
#define MAC_BEACON_ORDER                  (0x47)
#define MAC_GTS_PERMIT                    (0x4d)
#define MAC_MAX_CSMA_BACKOFFS             (0x4e)
#define MAC_MIN_BE                        (0x4f)
#define MAC_PAN_ID                        (0x50)
#define MAC_PROMISCUOUS_MODE              (0x51)
#define MAC_RX_ON_WHEN_IDLE               (0x52)
#define MAC_SHORT_ADDRESS                 (0x53)
#define MAC_SUPERFRAME_ORDER              (0x54)
#define MAC_ASSOCIATED_PAN_COORD          (0x56)
#define MAC_MAX_BE                        (0x57)
#define MAC_MAX_FRAME_RETRIES             (0x59)
#define MAC_RESPONSE_WAIT_TIME            (0x5A)
#define MAC_SECURITY_ENABLED              (0x5D)

#define MAC_AUTO_REQUEST_SECURITY_LEVEL   (0x78)
#define MAC_AUTO_REQUEST_KEY_ID_MODE      (0x79)

#define NS_IEEE_ADDRESS                   (0xFF) /* Non-standard IEEE address */

/* MAC Address Mode Definitions */
#define MAC_MODE_NO_ADDR                (0x00)
#define MAC_MODE_SHORT_ADDR             (0x02)
#define MAC_MODE_LONG_ADDR              (0x03)

/* MAC constants */
#define MAX_BEACON_OVERHEAD        (75)
#define MAX_BEACON_PAYLOAD_LENGTH  (IEEE802154_MTU - MAX_BEACON_OVERHEAD)

#define MAX_ATTRIBUTE_SIZE              (122)
#define MAX_DATA_SIZE                   (114)

#define CA8210_VALID_CHANNELS                 (0x07FFF800)

/* MAC workarounds for V1.1 and MPW silicon (V0.x) */
#define CA8210_MAC_WORKAROUNDS (0)
#define CA8210_MAC_MPW         (0)

/* memory manipulation macros */
#define LS_BYTE(x)     ((u8)((x) & 0xFF))
#define MS_BYTE(x)     ((u8)(((x) >> 8) & 0xFF))

/* message ID codes in SPI commands */
/* downstream */
#define MCPS_DATA_REQUEST                     (0x00)
#define MLME_ASSOCIATE_REQUEST                (0x02)
#define MLME_ASSOCIATE_RESPONSE               (0x03)
#define MLME_DISASSOCIATE_REQUEST             (0x04)
#define MLME_GET_REQUEST                      (0x05)
#define MLME_ORPHAN_RESPONSE                  (0x06)
#define MLME_RESET_REQUEST                    (0x07)
#define MLME_RX_ENABLE_REQUEST                (0x08)
#define MLME_SCAN_REQUEST                     (0x09)
#define MLME_SET_REQUEST                      (0x0A)
#define MLME_START_REQUEST                    (0x0B)
#define MLME_POLL_REQUEST                     (0x0D)
#define HWME_SET_REQUEST                      (0x0E)
#define HWME_GET_REQUEST                      (0x0F)
#define TDME_SETSFR_REQUEST                   (0x11)
#define TDME_GETSFR_REQUEST                   (0x12)
#define TDME_SET_REQUEST                      (0x14)
/* upstream */
#define MCPS_DATA_INDICATION                  (0x00)
#define MCPS_DATA_CONFIRM                     (0x01)
#define MLME_RESET_CONFIRM                    (0x0A)
#define MLME_SET_CONFIRM                      (0x0E)
#define MLME_START_CONFIRM                    (0x0F)
#define HWME_SET_CONFIRM                      (0x12)
#define HWME_GET_CONFIRM                      (0x13)
#define HWME_WAKEUP_INDICATION                (0x15)
#define TDME_SETSFR_CONFIRM                   (0x17)

/* SPI command IDs */
/* bit indicating a confirm or indication from slave to master */
#define SPI_S2M                            (0x20)
/* bit indicating a synchronous message */
#define SPI_SYN                            (0x40)

/* SPI command definitions */
#define SPI_IDLE                           (0xFF)
#define SPI_NACK                           (0xF0)

#define SPI_MCPS_DATA_REQUEST          (MCPS_DATA_REQUEST)
#define SPI_MCPS_DATA_INDICATION       (MCPS_DATA_INDICATION + SPI_S2M)
#define SPI_MCPS_DATA_CONFIRM          (MCPS_DATA_CONFIRM + SPI_S2M)

#define SPI_MLME_ASSOCIATE_REQUEST     (MLME_ASSOCIATE_REQUEST)
#define SPI_MLME_RESET_REQUEST         (MLME_RESET_REQUEST + SPI_SYN)
#define SPI_MLME_SET_REQUEST           (MLME_SET_REQUEST + SPI_SYN)
#define SPI_MLME_START_REQUEST         (MLME_START_REQUEST + SPI_SYN)
#define SPI_MLME_RESET_CONFIRM         (MLME_RESET_CONFIRM + SPI_S2M + SPI_SYN)
#define SPI_MLME_SET_CONFIRM           (MLME_SET_CONFIRM + SPI_S2M + SPI_SYN)
#define SPI_MLME_START_CONFIRM         (MLME_START_CONFIRM + SPI_S2M + SPI_SYN)

#define SPI_HWME_SET_REQUEST           (HWME_SET_REQUEST + SPI_SYN)
#define SPI_HWME_GET_REQUEST           (HWME_GET_REQUEST + SPI_SYN)
#define SPI_HWME_SET_CONFIRM           (HWME_SET_CONFIRM + SPI_S2M + SPI_SYN)
#define SPI_HWME_GET_CONFIRM           (HWME_GET_CONFIRM + SPI_S2M + SPI_SYN)
#define SPI_HWME_WAKEUP_INDICATION     (HWME_WAKEUP_INDICATION + SPI_S2M)

#define SPI_TDME_SETSFR_REQUEST        (TDME_SETSFR_REQUEST + SPI_SYN)
#define SPI_TDME_SET_REQUEST           (TDME_SET_REQUEST + SPI_SYN)
#define SPI_TDME_SETSFR_CONFIRM        (TDME_SETSFR_CONFIRM + SPI_S2M + SPI_SYN)

/* TDME SFR addresses */
/* Page 0 */
#define CA8210_SFR_PACFG                   (0xB1)
#define CA8210_SFR_MACCON                  (0xD8)
#define CA8210_SFR_PACFGIB                 (0xFE)
/* Page 1 */
#define CA8210_SFR_LOTXCAL                 (0xBF)
#define CA8210_SFR_PTHRH                   (0xD1)
#define CA8210_SFR_PRECFG                  (0xD3)
#define CA8210_SFR_LNAGX40                 (0xE1)
#define CA8210_SFR_LNAGX41                 (0xE2)
#define CA8210_SFR_LNAGX42                 (0xE3)
#define CA8210_SFR_LNAGX43                 (0xE4)
#define CA8210_SFR_LNAGX44                 (0xE5)
#define CA8210_SFR_LNAGX45                 (0xE6)
#define CA8210_SFR_LNAGX46                 (0xE7)
#define CA8210_SFR_LNAGX47                 (0xE9)

#define PACFGIB_DEFAULT_CURRENT            (0x3F)
#define PTHRH_DEFAULT_THRESHOLD            (0x5A)
#define LNAGX40_DEFAULT_GAIN               (0x29) /* 10dB */
#define LNAGX41_DEFAULT_GAIN               (0x54) /* 21dB */
#define LNAGX42_DEFAULT_GAIN               (0x6C) /* 27dB */
#define LNAGX43_DEFAULT_GAIN               (0x7A) /* 30dB */
#define LNAGX44_DEFAULT_GAIN               (0x84) /* 33dB */
#define LNAGX45_DEFAULT_GAIN               (0x8B) /* 34dB */
#define LNAGX46_DEFAULT_GAIN               (0x92) /* 36dB */
#define LNAGX47_DEFAULT_GAIN               (0x96) /* 37dB */

#define CA8210_IOCTL_HARD_RESET            (0x00)

/* Structs/Enums */

/**
 * struct cas_control - spi transfer structure
 * @msg:                  spi_message for each exchange
 * @transfer:             spi_transfer for each exchange
 * @tx_buf:               source array for transmission
 * @tx_in_buf:            array storing bytes received during transmission
 * @priv:                 pointer to private data
 *
 * This structure stores all the necessary data passed around during a single
 * spi exchange.
 */
struct cas_control {
        struct spi_message msg;
        struct spi_transfer transfer;

        u8 tx_buf[CA8210_SPI_BUF_SIZE];
        u8 tx_in_buf[CA8210_SPI_BUF_SIZE];

        struct ca8210_priv *priv;
};

/**
 * struct ca8210_test - ca8210 test interface structure
 * @ca8210_dfs_spi_int: pointer to the entry in the debug fs for this device
 * @up_fifo:            fifo for upstream messages
 *
 * This structure stores all the data pertaining to the debug interface
 */
struct ca8210_test {
        struct dentry *ca8210_dfs_spi_int;
        struct kfifo up_fifo;
        wait_queue_head_t readq;
};

/**
 * struct ca8210_priv - ca8210 private data structure
 * @spi:                    pointer to the ca8210 spi device object
 * @hw:                     pointer to the ca8210 ieee802154_hw object
 * @hw_registered:          true if hw has been registered with ieee802154
 * @lock:                   spinlock protecting the private data area
 * @mlme_workqueue:           workqueue for triggering MLME Reset
 * @irq_workqueue:          workqueue for irq processing
 * @tx_skb:                 current socket buffer to transmit
 * @nextmsduhandle:         msdu handle to pass to the 15.4 MAC layer for the
 *                           next transmission
 * @clk:                    external clock provided by the ca8210
 * @last_dsn:               sequence number of last data packet received, for
 *                           resend detection
 * @test:                   test interface data section for this instance
 * @async_tx_pending:       true if an asynchronous transmission was started and
 *                           is not complete
 * @sync_command_response:  pointer to buffer to fill with sync response
 * @ca8210_is_awake:        nonzero if ca8210 is initialised, ready for comms
 * @sync_down:              counts number of downstream synchronous commands
 * @sync_up:                counts number of upstream synchronous commands
 * @spi_transfer_complete   completion object for a single spi_transfer
 * @sync_exchange_complete  completion object for a complete synchronous API
 *                           exchange
 * @promiscuous             whether the ca8210 is in promiscuous mode or not
 * @retries:                records how many times the current pending spi
 *                           transfer has been retried
 */
struct ca8210_priv {
        struct spi_device *spi;
        struct ieee802154_hw *hw;
        bool hw_registered;
        spinlock_t lock;
        struct workqueue_struct *mlme_workqueue;
        struct workqueue_struct *irq_workqueue;
        struct sk_buff *tx_skb;
        u8 nextmsduhandle;
        struct clk *clk;
        int last_dsn;
        struct ca8210_test test;
        bool async_tx_pending;
        u8 *sync_command_response;
        struct completion ca8210_is_awake;
        int sync_down, sync_up;
        struct completion spi_transfer_complete, sync_exchange_complete;
        bool promiscuous;
        int retries;
};

/**
 * struct work_priv_container - link between a work object and the relevant
 *                              device's private data
 * @work: work object being executed
 * @priv: device's private data section
 *
 */
struct work_priv_container {
        struct work_struct work;
        struct ca8210_priv *priv;
};

/**
 * struct ca8210_platform_data - ca8210 platform data structure
 * @extclockenable: true if the external clock is to be enabled
 * @extclockfreq:   frequency of the external clock
 * @extclockgpio:   ca8210 output gpio of the external clock
 * @gpio_reset:     gpio number of ca8210 reset line
 * @gpio_irq:       gpio number of ca8210 interrupt line
 * @irq_id:         identifier for the ca8210 irq
 *
 */
struct ca8210_platform_data {
        bool extclockenable;
        unsigned int extclockfreq;
        unsigned int extclockgpio;
        int gpio_reset;
        int gpio_irq;
        int irq_id;
};

/**
 * struct fulladdr - full MAC addressing information structure
 * @mode:    address mode (none, short, extended)
 * @pan_id:  16-bit LE pan id
 * @address: LE address, variable length as specified by mode
 *
 */
struct fulladdr {
        u8         mode;
        u8         pan_id[2];
        u8         address[8];
};

/**
 * union macaddr: generic MAC address container
 * @short_addr:   16-bit short address
 * @ieee_address: 64-bit extended address as LE byte array
 *
 */
union macaddr {
        u16        short_address;
        u8         ieee_address[8];
};

/**
 * struct secspec: security specification for SAP commands
 * @security_level: 0-7, controls level of authentication & encryption
 * @key_id_mode:    0-3, specifies how to obtain key
 * @key_source:     extended key retrieval data
 * @key_index:      single-byte key identifier
 *
 */
struct secspec {
        u8         security_level;
        u8         key_id_mode;
        u8         key_source[8];
        u8         key_index;
};

/* downlink functions parameter set definitions */
struct mcps_data_request_pset {
        u8              src_addr_mode;
        struct fulladdr dst;
        u8              msdu_length;
        u8              msdu_handle;
        u8              tx_options;
        u8              msdu[MAX_DATA_SIZE];
};

struct mlme_set_request_pset {
        u8         pib_attribute;
        u8         pib_attribute_index;
        u8         pib_attribute_length;
        u8         pib_attribute_value[MAX_ATTRIBUTE_SIZE];
};

struct hwme_set_request_pset {
        u8         hw_attribute;
        u8         hw_attribute_length;
        u8         hw_attribute_value[MAX_HWME_ATTRIBUTE_SIZE];
};

struct hwme_get_request_pset {
        u8         hw_attribute;
};

struct tdme_setsfr_request_pset {
        u8         sfr_page;
        u8         sfr_address;
        u8         sfr_value;
};

/* uplink functions parameter set definitions */
struct hwme_set_confirm_pset {
        u8         status;
        u8         hw_attribute;
};

struct hwme_get_confirm_pset {
        u8         status;
        u8         hw_attribute;
        u8         hw_attribute_length;
        u8         hw_attribute_value[MAX_HWME_ATTRIBUTE_SIZE];
};

struct tdme_setsfr_confirm_pset {
        u8         status;
        u8         sfr_page;
        u8         sfr_address;
};

struct mac_message {
        u8      command_id;
        u8      length;
        union {
                struct mcps_data_request_pset       data_req;
                struct mlme_set_request_pset        set_req;
                struct hwme_set_request_pset        hwme_set_req;
                struct hwme_get_request_pset        hwme_get_req;
                struct tdme_setsfr_request_pset     tdme_set_sfr_req;
                struct hwme_set_confirm_pset        hwme_set_cnf;
                struct hwme_get_confirm_pset        hwme_get_cnf;
                struct tdme_setsfr_confirm_pset     tdme_set_sfr_cnf;
                u8                                  u8param;
                u8                                  status;
                u8                                  payload[148];
        } pdata;
};

union pa_cfg_sfr {
        struct {
                u8 bias_current_trim     : 3;
                u8 /* reserved */        : 1;
                u8 buffer_capacitor_trim : 3;
                u8 boost                 : 1;
        };
        u8 paib;
};

struct preamble_cfg_sfr {
        u8 timeout_symbols      : 3;
        u8 acquisition_symbols  : 3;
        u8 search_symbols       : 2;
};

static int (*cascoda_api_upstream)(
        const u8 *buf,
        size_t len,
        void *device_ref
);

/**
 * link_to_linux_err() - Translates an 802.15.4 return code into the closest
 *                       linux error
 * @link_status:  802.15.4 status code
 *
 * Return: 0 or Linux error code
 */
static int link_to_linux_err(int link_status)
{
        if (link_status < 0) {
                /* status is already a Linux code */
                return link_status;
        }
        switch (link_status) {
        case MAC_SUCCESS:
        case MAC_REALIGNMENT:
                return 0;
        case MAC_IMPROPER_KEY_TYPE:
                return -EKEYREJECTED;
        case MAC_IMPROPER_SECURITY_LEVEL:
        case MAC_UNSUPPORTED_LEGACY:
        case MAC_DENIED:
                return -EACCES;
        case MAC_BEACON_LOST:
        case MAC_NO_ACK:
        case MAC_NO_BEACON:
                return -ENETUNREACH;
        case MAC_CHANNEL_ACCESS_FAILURE:
        case MAC_TX_ACTIVE:
        case MAC_SCAN_IN_PROGRESS:
                return -EBUSY;
        case MAC_DISABLE_TRX_FAILURE:
        case MAC_OUT_OF_CAP:
                return -EAGAIN;
        case MAC_FRAME_TOO_LONG:
                return -EMSGSIZE;
        case MAC_INVALID_GTS:
        case MAC_PAST_TIME:
                return -EBADSLT;
        case MAC_INVALID_HANDLE:
                return -EBADMSG;
        case MAC_INVALID_PARAMETER:
        case MAC_UNSUPPORTED_ATTRIBUTE:
        case MAC_ON_TIME_TOO_LONG:
        case MAC_INVALID_INDEX:
                return -EINVAL;
        case MAC_NO_DATA:
                return -ENODATA;
        case MAC_NO_SHORT_ADDRESS:
                return -EFAULT;
        case MAC_PAN_ID_CONFLICT:
                return -EADDRINUSE;
        case MAC_TRANSACTION_EXPIRED:
                return -ETIME;
        case MAC_TRANSACTION_OVERFLOW:
                return -ENOBUFS;
        case MAC_UNAVAILABLE_KEY:
                return -ENOKEY;
        case MAC_INVALID_ADDRESS:
                return -ENXIO;
        case MAC_TRACKING_OFF:
        case MAC_SUPERFRAME_OVERLAP:
                return -EREMOTEIO;
        case MAC_LIMIT_REACHED:
                return -EDQUOT;
        case MAC_READ_ONLY:
                return -EROFS;
        default:
                return -EPROTO;
        }
}

/**
 * ca8210_test_int_driver_write() - Writes a message to the test interface to be
 *                                  read by the userspace
 * @buf:  Buffer containing upstream message
 * @len:  length of message to write
 * @spi:  SPI device of message originator
 *
 * Return: 0 or linux error code
 */
static int ca8210_test_int_driver_write(
        const u8       *buf,
        size_t          len,
        void           *spi
)
{
        struct ca8210_priv *priv = spi_get_drvdata(spi);
        struct ca8210_test *test = &priv->test;
        char *fifo_buffer;
        int i;

        dev_dbg(
                &priv->spi->dev,
                "test_interface: Buffering upstream message:\n"
        );
        for (i = 0; i < len; i++)
                dev_dbg(&priv->spi->dev, "%#03x\n", buf[i]);

        fifo_buffer = kmemdup(buf, len, GFP_KERNEL);
        if (!fifo_buffer)
                return -ENOMEM;
        kfifo_in(&test->up_fifo, &fifo_buffer, 4);
        wake_up_interruptible(&priv->test.readq);

        return 0;
}

/* SPI Operation */

static int ca8210_net_rx(
        struct ieee802154_hw  *hw,
        u8                    *command,
        size_t                 len
);
static u8 mlme_reset_request_sync(
        u8       set_default_pib,
        void    *device_ref
);
static int ca8210_spi_transfer(
        struct spi_device *spi,
        const u8          *buf,
        size_t             len
);

/**
 * ca8210_reset_send() - Hard resets the ca8210 for a given time
 * @spi:  Pointer to target ca8210 spi device
 * @ms:   Milliseconds to hold the reset line low for
 */
static void ca8210_reset_send(struct spi_device *spi, unsigned int ms)
{
        struct ca8210_platform_data *pdata = spi->dev.platform_data;
        struct ca8210_priv *priv = spi_get_drvdata(spi);
        long status;

        gpio_set_value(pdata->gpio_reset, 0);
        reinit_completion(&priv->ca8210_is_awake);
        msleep(ms);
        gpio_set_value(pdata->gpio_reset, 1);
        priv->promiscuous = false;

        /* Wait until wakeup indication seen */
        status = wait_for_completion_interruptible_timeout(
                &priv->ca8210_is_awake,
                msecs_to_jiffies(CA8210_SYNC_TIMEOUT)
        );
        if (status == 0) {
                dev_crit(
                        &spi->dev,
                        "Fatal: No wakeup from ca8210 after reset!\n"
                );
        }

        dev_dbg(&spi->dev, "Reset the device\n");
}

/**
 * ca8210_mlme_reset_worker() - Resets the MLME, Called when the MAC OVERFLOW
 *                              condition happens.
 * @work:  Pointer to work being executed
 */
static void ca8210_mlme_reset_worker(struct work_struct *work)
{
        struct work_priv_container *wpc = container_of(
                work,
                struct work_priv_container,
                work
        );
        struct ca8210_priv *priv = wpc->priv;

        mlme_reset_request_sync(0, priv->spi);
        kfree(wpc);
}

/**
 * ca8210_rx_done() - Calls various message dispatches responding to a received
 *                    command
 * @arg:  Pointer to the cas_control object for the relevant spi transfer
 *
 * Presents a received SAP command from the ca8210 to the Cascoda EVBME, test
 * interface and network driver.
 */
static void ca8210_rx_done(struct cas_control *cas_ctl)
{
        u8 *buf;
        unsigned int len;
        struct work_priv_container *mlme_reset_wpc;
        struct ca8210_priv *priv = cas_ctl->priv;

        buf = cas_ctl->tx_in_buf;
        len = buf[1] + 2;
        if (len > CA8210_SPI_BUF_SIZE) {
                dev_crit(
                        &priv->spi->dev,
                        "Received packet len (%u) erroneously long\n",
                        len
                );
                goto finish;
        }

        if (buf[0] & SPI_SYN) {
                if (priv->sync_command_response) {
                        memcpy(priv->sync_command_response, buf, len);
                        complete(&priv->sync_exchange_complete);
                } else {
                        if (cascoda_api_upstream)
                                cascoda_api_upstream(buf, len, priv->spi);
                        priv->sync_up++;
                }
        } else {
                if (cascoda_api_upstream)
                        cascoda_api_upstream(buf, len, priv->spi);
        }

        ca8210_net_rx(priv->hw, buf, len);
        if (buf[0] == SPI_MCPS_DATA_CONFIRM) {
                if (buf[3] == MAC_TRANSACTION_OVERFLOW) {
                        dev_info(
                                &priv->spi->dev,
                                "Waiting for transaction overflow to stabilise...\n");
                        msleep(2000);
                        dev_info(
                                &priv->spi->dev,
                                "Resetting MAC...\n");

                        mlme_reset_wpc = kmalloc(sizeof(*mlme_reset_wpc),
                                                 GFP_KERNEL);
                        if (!mlme_reset_wpc)
                                goto finish;
                        INIT_WORK(
                                &mlme_reset_wpc->work,
                                ca8210_mlme_reset_worker
                        );
                        mlme_reset_wpc->priv = priv;
                        queue_work(priv->mlme_workqueue, &mlme_reset_wpc->work);
                }
        } else if (buf[0] == SPI_HWME_WAKEUP_INDICATION) {
                dev_notice(
                        &priv->spi->dev,
                        "Wakeup indication received, reason:\n"
                );
                switch (buf[2]) {
                case 0:
                        dev_notice(
                                &priv->spi->dev,
                                "Transceiver woken up from Power Up / System Reset\n"
                        );
                        break;
                case 1:
                        dev_notice(
                                &priv->spi->dev,
                                "Watchdog Timer Time-Out\n"
                        );
                        break;
                case 2:
                        dev_notice(
                                &priv->spi->dev,
                                "Transceiver woken up from Power-Off by Sleep Timer Time-Out\n");
                        break;
                case 3:
                        dev_notice(
                                &priv->spi->dev,
                                "Transceiver woken up from Power-Off by GPIO Activity\n"
                        );
                        break;
                case 4:
                        dev_notice(
                                &priv->spi->dev,
                                "Transceiver woken up from Standby by Sleep Timer Time-Out\n"
                        );
                        break;
                case 5:
                        dev_notice(
                                &priv->spi->dev,
                                "Transceiver woken up from Standby by GPIO Activity\n"
                        );
                        break;
                case 6:
                        dev_notice(
                                &priv->spi->dev,
                                "Sleep-Timer Time-Out in Active Mode\n"
                        );
                        break;
                default:
                        dev_warn(&priv->spi->dev, "Wakeup reason unknown\n");
                        break;
                }
                complete(&priv->ca8210_is_awake);
        }

finish:;
}

static int ca8210_remove(struct spi_device *spi_device);

/**
 * ca8210_spi_transfer_complete() - Called when a single spi transfer has
 *                                  completed
 * @context:  Pointer to the cas_control object for the finished transfer
 */
static void ca8210_spi_transfer_complete(void *context)
{
        struct cas_control *cas_ctl = context;
        struct ca8210_priv *priv = cas_ctl->priv;
        bool duplex_rx = false;
        int i;
        u8 retry_buffer[CA8210_SPI_BUF_SIZE];

        if (
                cas_ctl->tx_in_buf[0] == SPI_NACK ||
                (cas_ctl->tx_in_buf[0] == SPI_IDLE &&
                cas_ctl->tx_in_buf[1] == SPI_NACK)
        ) {
                /* ca8210 is busy */
                dev_info(&priv->spi->dev, "ca8210 was busy during attempted write\n");
                if (cas_ctl->tx_buf[0] == SPI_IDLE) {
                        dev_warn(
                                &priv->spi->dev,
                                "IRQ servicing NACKd, dropping transfer\n"
                        );
                        kfree(cas_ctl);
                        return;
                }
                if (priv->retries > 3) {
                        dev_err(&priv->spi->dev, "too many retries!\n");
                        kfree(cas_ctl);
                        ca8210_remove(priv->spi);
                        return;
                }
                memcpy(retry_buffer, cas_ctl->tx_buf, CA8210_SPI_BUF_SIZE);
                kfree(cas_ctl);
                ca8210_spi_transfer(
                        priv->spi,
                        retry_buffer,
                        CA8210_SPI_BUF_SIZE
                );
                priv->retries++;
                dev_info(&priv->spi->dev, "retried spi write\n");
                return;
        } else if (
                        cas_ctl->tx_in_buf[0] != SPI_IDLE &&
                        cas_ctl->tx_in_buf[0] != SPI_NACK
                ) {
                duplex_rx = true;
        }

        if (duplex_rx) {
                dev_dbg(&priv->spi->dev, "READ CMD DURING TX\n");
                for (i = 0; i < cas_ctl->tx_in_buf[1] + 2; i++)
                        dev_dbg(
                                &priv->spi->dev,
                                "%#03x\n",
                                cas_ctl->tx_in_buf[i]
                        );
                ca8210_rx_done(cas_ctl);
        }
        complete(&priv->spi_transfer_complete);
        kfree(cas_ctl);
        priv->retries = 0;
}

/**
 * ca8210_spi_transfer() - Initiate duplex spi transfer with ca8210
 * @spi: Pointer to spi device for transfer
 * @buf: Octet array to send
 * @len: length of the buffer being sent
 *
 * Return: 0 or linux error code
 */
static int ca8210_spi_transfer(
        struct spi_device  *spi,
        const u8           *buf,
        size_t              len
)
{
        int i, status = 0;
        struct ca8210_priv *priv;
        struct cas_control *cas_ctl;

        if (!spi) {
                pr_crit("NULL spi device passed to %s\n", __func__);
                return -ENODEV;
        }

        priv = spi_get_drvdata(spi);
        reinit_completion(&priv->spi_transfer_complete);

        dev_dbg(&spi->dev, "%s called\n", __func__);

        cas_ctl = kmalloc(sizeof(*cas_ctl), GFP_ATOMIC);
        if (!cas_ctl)
                return -ENOMEM;

        cas_ctl->priv = priv;
        memset(cas_ctl->tx_buf, SPI_IDLE, CA8210_SPI_BUF_SIZE);
        memset(cas_ctl->tx_in_buf, SPI_IDLE, CA8210_SPI_BUF_SIZE);
        memcpy(cas_ctl->tx_buf, buf, len);

        for (i = 0; i < len; i++)
                dev_dbg(&spi->dev, "%#03x\n", cas_ctl->tx_buf[i]);

        spi_message_init(&cas_ctl->msg);

        cas_ctl->transfer.tx_nbits = 1; /* 1 MOSI line */
        cas_ctl->transfer.rx_nbits = 1; /* 1 MISO line */
        cas_ctl->transfer.speed_hz = 0; /* Use device setting */
        cas_ctl->transfer.bits_per_word = 0; /* Use device setting */
        cas_ctl->transfer.tx_buf = cas_ctl->tx_buf;
        cas_ctl->transfer.rx_buf = cas_ctl->tx_in_buf;
        cas_ctl->transfer.delay_usecs = 0;
        cas_ctl->transfer.cs_change = 0;
        cas_ctl->transfer.len = sizeof(struct mac_message);
        cas_ctl->msg.complete = ca8210_spi_transfer_complete;
        cas_ctl->msg.context = cas_ctl;

        spi_message_add_tail(
                &cas_ctl->transfer,
                &cas_ctl->msg
        );

        status = spi_async(spi, &cas_ctl->msg);
        if (status < 0) {
                dev_crit(
                        &spi->dev,
                        "status %d from spi_sync in write\n",
                        status
                );
        }

        return status;
}

/**
 * ca8210_spi_exchange() - Exchange API/SAP commands with the radio
 * @buf:         Octet array of command being sent downstream
 * @len:         length of buf
 * @response:    buffer for storing synchronous response
 * @device_ref:  spi_device pointer for ca8210
 *
 * Effectively calls ca8210_spi_transfer to write buf[] to the spi, then for
 * synchronous commands waits for the corresponding response to be read from
 * the spi before returning. The response is written to the response parameter.
 *
 * Return: 0 or linux error code
 */
static int ca8210_spi_exchange(
        const u8 *buf,
        size_t len,
        u8 *response,
        void *device_ref
)
{
        int status = 0;
        struct spi_device *spi = device_ref;
        struct ca8210_priv *priv = spi->dev.driver_data;
        long wait_remaining;

        if ((buf[0] & SPI_SYN) && response) { /* if sync wait for confirm */
                reinit_completion(&priv->sync_exchange_complete);
                priv->sync_command_response = response;
        }

        do {
                reinit_completion(&priv->spi_transfer_complete);
                status = ca8210_spi_transfer(priv->spi, buf, len);
                if (status) {
                        dev_warn(
                                &spi->dev,
                                "spi write failed, returned %d\n",
                                status
                        );
                        if (status == -EBUSY)
                                continue;
                        if (((buf[0] & SPI_SYN) && response))
                                complete(&priv->sync_exchange_complete);
                        goto cleanup;
                }

                wait_remaining = wait_for_completion_interruptible_timeout(
                        &priv->spi_transfer_complete,
                        msecs_to_jiffies(1000)
                );
                if (wait_remaining == -ERESTARTSYS) {
                        status = -ERESTARTSYS;
                } else if (wait_remaining == 0) {
                        dev_err(
                                &spi->dev,
                                "SPI downstream transfer timed out!\n"
                        );
                        status = -ETIME;
                        goto cleanup;
                }
        } while (status < 0);

        if (!((buf[0] & SPI_SYN) && response))
                goto cleanup;

        wait_remaining = wait_for_completion_interruptible_timeout(
                &priv->sync_exchange_complete,
                msecs_to_jiffies(CA8210_SYNC_TIMEOUT)
        );
        if (wait_remaining == -ERESTARTSYS) {
                status = -ERESTARTSYS;
        } else if (wait_remaining == 0) {
                dev_err(
                        &spi->dev,
                        "Synchronous confirm timeout\n"
                );
                status = -ETIME;
        }

cleanup:
        priv->sync_command_response = NULL;
        return status;
}

/**
 * ca8210_interrupt_handler() - Called when an irq is received from the ca8210
 * @irq:     Id of the irq being handled
 * @dev_id:  Pointer passed by the system, pointing to the ca8210's private data
 *
 * This function is called when the irq line from the ca8210 is asserted,
 * signifying that the ca8210 has a message to send upstream to us. Starts the
 * asynchronous spi read.
 *
 * Return: irq return code
 */
static irqreturn_t ca8210_interrupt_handler(int irq, void *dev_id)
{
        struct ca8210_priv *priv = dev_id;
        int status;

        dev_dbg(&priv->spi->dev, "irq: Interrupt occurred\n");
        do {
                status = ca8210_spi_transfer(priv->spi, NULL, 0);
                if (status && (status != -EBUSY)) {
                        dev_warn(
                                &priv->spi->dev,
                                "spi read failed, returned %d\n",
                                status
                        );
                }
        } while (status == -EBUSY);
        return IRQ_HANDLED;
}

static int (*cascoda_api_downstream)(
        const u8 *buf,
        size_t len,
        u8 *response,
        void *device_ref
) = ca8210_spi_exchange;

/* Cascoda API / 15.4 SAP Primitives */

/**
 * tdme_setsfr_request_sync() - TDME_SETSFR_request/confirm according to API
 * @sfr_page:    SFR Page
 * @sfr_address: SFR Address
 * @sfr_value:   SFR Value
 * @device_ref:  Nondescript pointer to target device
 *
 * Return: 802.15.4 status code of TDME-SETSFR.confirm
 */
static u8 tdme_setsfr_request_sync(
        u8            sfr_page,
        u8            sfr_address,
        u8            sfr_value,
        void         *device_ref
)
{
        int ret;
        struct mac_message command, response;
        struct spi_device *spi = device_ref;

        command.command_id = SPI_TDME_SETSFR_REQUEST;
        command.length = 3;
        command.pdata.tdme_set_sfr_req.sfr_page    = sfr_page;
        command.pdata.tdme_set_sfr_req.sfr_address = sfr_address;
        command.pdata.tdme_set_sfr_req.sfr_value   = sfr_value;
        response.command_id = SPI_IDLE;
        ret = cascoda_api_downstream(
                &command.command_id,
                command.length + 2,
                &response.command_id,
                device_ref
        );
        if (ret) {
                dev_crit(&spi->dev, "cascoda_api_downstream returned %d", ret);
                return MAC_SYSTEM_ERROR;
        }

        if (response.command_id != SPI_TDME_SETSFR_CONFIRM) {
                dev_crit(
                        &spi->dev,
                        "sync response to SPI_TDME_SETSFR_REQUEST was not SPI_TDME_SETSFR_CONFIRM, it was %d\n",
                        response.command_id
                );
                return MAC_SYSTEM_ERROR;
        }

        return response.pdata.tdme_set_sfr_cnf.status;
}

/**
 * tdme_chipinit() - TDME Chip Register Default Initialisation Macro
 * @device_ref: Nondescript pointer to target device
 *
 * Return: 802.15.4 status code of API calls
 */
static u8 tdme_chipinit(void *device_ref)
{
        u8 status = MAC_SUCCESS;
        u8 sfr_address;
        struct spi_device *spi = device_ref;
        struct preamble_cfg_sfr pre_cfg_value = {
                .timeout_symbols     = 3,
                .acquisition_symbols = 3,
                .search_symbols      = 1,
        };
        /* LNA Gain Settings */
        status = tdme_setsfr_request_sync(
                1, (sfr_address = CA8210_SFR_LNAGX40),
                LNAGX40_DEFAULT_GAIN, device_ref);
        if (status)
                goto finish;
        status = tdme_setsfr_request_sync(
                1, (sfr_address = CA8210_SFR_LNAGX41),
                LNAGX41_DEFAULT_GAIN, device_ref);
        if (status)
                goto finish;
        status = tdme_setsfr_request_sync(
                1, (sfr_address = CA8210_SFR_LNAGX42),
                LNAGX42_DEFAULT_GAIN, device_ref);
        if (status)
                goto finish;
        status = tdme_setsfr_request_sync(
                1, (sfr_address = CA8210_SFR_LNAGX43),
                LNAGX43_DEFAULT_GAIN, device_ref);
        if (status)
                goto finish;
        status = tdme_setsfr_request_sync(
                1, (sfr_address = CA8210_SFR_LNAGX44),
                LNAGX44_DEFAULT_GAIN, device_ref);
        if (status)
                goto finish;
        status = tdme_setsfr_request_sync(
                1, (sfr_address = CA8210_SFR_LNAGX45),
                LNAGX45_DEFAULT_GAIN, device_ref);
        if (status)
                goto finish;
        status = tdme_setsfr_request_sync(
                1, (sfr_address = CA8210_SFR_LNAGX46),
                LNAGX46_DEFAULT_GAIN, device_ref);
        if (status)
                goto finish;
        status = tdme_setsfr_request_sync(
                1, (sfr_address = CA8210_SFR_LNAGX47),
                LNAGX47_DEFAULT_GAIN, device_ref);
        if (status)
                goto finish;
        /* Preamble Timing Config */
        status = tdme_setsfr_request_sync(
                1, (sfr_address = CA8210_SFR_PRECFG),
                *((u8 *)&pre_cfg_value), device_ref);
        if (status)
                goto finish;
        /* Preamble Threshold High */
        status = tdme_setsfr_request_sync(
                1, (sfr_address = CA8210_SFR_PTHRH),
                PTHRH_DEFAULT_THRESHOLD, device_ref);
        if (status)
                goto finish;
        /* Tx Output Power 8 dBm */
        status = tdme_setsfr_request_sync(
                0, (sfr_address = CA8210_SFR_PACFGIB),
                PACFGIB_DEFAULT_CURRENT, device_ref);
        if (status)
                goto finish;

finish:
        if (status != MAC_SUCCESS) {
                dev_err(
                        &spi->dev,
                        "failed to set sfr at %#03x, status = %#03x\n",
                        sfr_address,
                        status
                );
        }
        return status;
}

/**
 * tdme_channelinit() - TDME Channel Register Default Initialisation Macro (Tx)
 * @channel:    802.15.4 channel to initialise chip for
 * @device_ref: Nondescript pointer to target device
 *
 * Return: 802.15.4 status code of API calls
 */
static u8 tdme_channelinit(u8 channel, void *device_ref)
{
        /* Transceiver front-end local oscillator tx two-point calibration
         * value. Tuned for the hardware.
         */
        u8 txcalval;

        if (channel >= 25)
                txcalval = 0xA7;
        else if (channel >= 23)
                txcalval = 0xA8;
        else if (channel >= 22)
                txcalval = 0xA9;
        else if (channel >= 20)
                txcalval = 0xAA;
        else if (channel >= 17)
                txcalval = 0xAB;
        else if (channel >= 16)
                txcalval = 0xAC;
        else if (channel >= 14)
                txcalval = 0xAD;
        else if (channel >= 12)
                txcalval = 0xAE;
        else
                txcalval = 0xAF;

        return tdme_setsfr_request_sync(
                1,
                CA8210_SFR_LOTXCAL,
                txcalval,
                device_ref
        );  /* LO Tx Cal */
}

/**
 * tdme_checkpibattribute() - Checks Attribute Values that are not checked in
 *                            MAC
 * @pib_attribute:        Attribute Number
 * @pib_attribute_length: Attribute length
 * @pib_attribute_value:  Pointer to Attribute Value
 * @device_ref:           Nondescript pointer to target device
 *
 * Return: 802.15.4 status code of checks
 */
static u8 tdme_checkpibattribute(
        u8            pib_attribute,
        u8            pib_attribute_length,
        const void   *pib_attribute_value
)
{
        u8 status = MAC_SUCCESS;
        u8 value;

        value  = *((u8 *)pib_attribute_value);

        switch (pib_attribute) {
        /* PHY */
        case PHY_TRANSMIT_POWER:
                if (value > 0x3F)
                        status = MAC_INVALID_PARAMETER;
                break;
        case PHY_CCA_MODE:
                if (value > 0x03)
                        status = MAC_INVALID_PARAMETER;
                break;
        /* MAC */
        case MAC_BATT_LIFE_EXT_PERIODS:
                if (value < 6 || value > 41)
                        status = MAC_INVALID_PARAMETER;
                break;
        case MAC_BEACON_PAYLOAD:
                if (pib_attribute_length > MAX_BEACON_PAYLOAD_LENGTH)
                        status = MAC_INVALID_PARAMETER;
                break;
        case MAC_BEACON_PAYLOAD_LENGTH:
                if (value > MAX_BEACON_PAYLOAD_LENGTH)
                        status = MAC_INVALID_PARAMETER;
                break;
        case MAC_BEACON_ORDER:
                if (value > 15)
                        status = MAC_INVALID_PARAMETER;
                break;
        case MAC_MAX_BE:
                if (value < 3 || value > 8)
                        status = MAC_INVALID_PARAMETER;
                break;
        case MAC_MAX_CSMA_BACKOFFS:
                if (value > 5)
                        status = MAC_INVALID_PARAMETER;
                break;
        case MAC_MAX_FRAME_RETRIES:
                if (value > 7)
                        status = MAC_INVALID_PARAMETER;
                break;
        case MAC_MIN_BE:
                if (value > 8)
                        status = MAC_INVALID_PARAMETER;
                break;
        case MAC_RESPONSE_WAIT_TIME:
                if (value < 2 || value > 64)
                        status = MAC_INVALID_PARAMETER;
                break;
        case MAC_SUPERFRAME_ORDER:
                if (value > 15)
                        status = MAC_INVALID_PARAMETER;
                break;
        /* boolean */
        case MAC_ASSOCIATED_PAN_COORD:
        case MAC_ASSOCIATION_PERMIT:
        case MAC_AUTO_REQUEST:
        case MAC_BATT_LIFE_EXT:
        case MAC_GTS_PERMIT:
        case MAC_PROMISCUOUS_MODE:
        case MAC_RX_ON_WHEN_IDLE:
        case MAC_SECURITY_ENABLED:
                if (value > 1)
                        status = MAC_INVALID_PARAMETER;
                break;
        /* MAC SEC */
        case MAC_AUTO_REQUEST_SECURITY_LEVEL:
                if (value > 7)
                        status = MAC_INVALID_PARAMETER;
                break;
        case MAC_AUTO_REQUEST_KEY_ID_MODE:
                if (value > 3)
                        status = MAC_INVALID_PARAMETER;
                break;
        default:
                break;
        }

        return status;
}

/**
 * tdme_settxpower() - Sets the tx power for MLME_SET phyTransmitPower
 * @txp:        Transmit Power
 * @device_ref: Nondescript pointer to target device
 *
 * Normalised to 802.15.4 Definition (6-bit, signed):
 * Bit 7-6: not used
 * Bit 5-0: tx power (-32 - +31 dB)
 *
 * Return: 802.15.4 status code of api calls
 */
static u8 tdme_settxpower(u8 txp, void *device_ref)
{
        u8 status;
        s8 txp_val;
        u8 txp_ext;
        union pa_cfg_sfr pa_cfg_val;

        /* extend from 6 to 8 bit */
        txp_ext = 0x3F & txp;
        if (txp_ext & 0x20)
                txp_ext += 0xC0;
        txp_val = (s8)txp_ext;

        if (CA8210_MAC_MPW) {
                if (txp_val > 0) {
                        /* 8 dBm: ptrim = 5, itrim = +3 => +4 dBm */
                        pa_cfg_val.bias_current_trim     = 3;
                        pa_cfg_val.buffer_capacitor_trim = 5;
                        pa_cfg_val.boost                 = 1;
                } else {
                        /* 0 dBm: ptrim = 7, itrim = +3 => -6 dBm */
                        pa_cfg_val.bias_current_trim     = 3;
                        pa_cfg_val.buffer_capacitor_trim = 7;
                        pa_cfg_val.boost                 = 0;
                }
                /* write PACFG */
                status = tdme_setsfr_request_sync(
                        0,
                        CA8210_SFR_PACFG,
                        pa_cfg_val.paib,
                        device_ref
                );
        } else {
                /* Look-Up Table for Setting Current and Frequency Trim values
                 * for desired Output Power
                 */
                if (txp_val > 8) {
                        pa_cfg_val.paib = 0x3F;
                } else if (txp_val == 8) {
                        pa_cfg_val.paib = 0x32;
                } else if (txp_val == 7) {
                        pa_cfg_val.paib = 0x22;
                } else if (txp_val == 6) {
                        pa_cfg_val.paib = 0x18;
                } else if (txp_val == 5) {
                        pa_cfg_val.paib = 0x10;
                } else if (txp_val == 4) {
                        pa_cfg_val.paib = 0x0C;
                } else if (txp_val == 3) {
                        pa_cfg_val.paib = 0x08;
                } else if (txp_val == 2) {
                        pa_cfg_val.paib = 0x05;
                } else if (txp_val == 1) {
                        pa_cfg_val.paib = 0x03;
                } else if (txp_val == 0) {
                        pa_cfg_val.paib = 0x01;
                } else { /* < 0 */
                        pa_cfg_val.paib = 0x00;
                }
                /* write PACFGIB */
                status = tdme_setsfr_request_sync(
                        0,
                        CA8210_SFR_PACFGIB,
                        pa_cfg_val.paib,
                        device_ref
                );
        }

        return status;
}

/**
 * mcps_data_request() - mcps_data_request (Send Data) according to API Spec
 * @src_addr_mode:    Source Addressing Mode
 * @dst_address_mode: Destination Addressing Mode
 * @dst_pan_id:       Destination PAN ID
 * @dst_addr:         Pointer to Destination Address
 * @msdu_length:      length of Data
 * @msdu:             Pointer to Data
 * @msdu_handle:      Handle of Data
 * @tx_options:       Tx Options Bit Field
 * @security:         Pointer to Security Structure or NULL
 * @device_ref:       Nondescript pointer to target device
 *
 * Return: 802.15.4 status code of action
 */
static u8 mcps_data_request(
        u8               src_addr_mode,
        u8               dst_address_mode,
        u16              dst_pan_id,
        union macaddr   *dst_addr,
        u8               msdu_length,
        u8              *msdu,
        u8               msdu_handle,
        u8               tx_options,
        struct secspec  *security,
        void            *device_ref
)
{
        struct secspec *psec;
        struct mac_message command;

        command.command_id = SPI_MCPS_DATA_REQUEST;
        command.pdata.data_req.src_addr_mode = src_addr_mode;
        command.pdata.data_req.dst.mode = dst_address_mode;
        if (dst_address_mode != MAC_MODE_NO_ADDR) {
                command.pdata.data_req.dst.pan_id[0] = LS_BYTE(dst_pan_id);
                command.pdata.data_req.dst.pan_id[1] = MS_BYTE(dst_pan_id);
                if (dst_address_mode == MAC_MODE_SHORT_ADDR) {
                        command.pdata.data_req.dst.address[0] = LS_BYTE(
                                dst_addr->short_address
                        );
                        command.pdata.data_req.dst.address[1] = MS_BYTE(
                                dst_addr->short_address
                        );
                } else {   /* MAC_MODE_LONG_ADDR*/
                        memcpy(
                                command.pdata.data_req.dst.address,
                                dst_addr->ieee_address,
                                8
                        );
                }
        }
        command.pdata.data_req.msdu_length = msdu_length;
        command.pdata.data_req.msdu_handle = msdu_handle;
        command.pdata.data_req.tx_options = tx_options;
        memcpy(command.pdata.data_req.msdu, msdu, msdu_length);
        psec = (struct secspec *)(command.pdata.data_req.msdu + msdu_length);
        command.length = sizeof(struct mcps_data_request_pset) -
                MAX_DATA_SIZE + msdu_length;
        if (!security || security->security_level == 0) {
                psec->security_level = 0;
                command.length += 1;
        } else {
                *psec = *security;
                command.length += sizeof(struct secspec);
        }

        if (ca8210_spi_transfer(device_ref, &command.command_id,
                                command.length + 2))
                return MAC_SYSTEM_ERROR;

        return MAC_SUCCESS;
}

/**
 * mlme_reset_request_sync() - MLME_RESET_request/confirm according to API Spec
 * @set_default_pib: Set defaults in PIB
 * @device_ref:      Nondescript pointer to target device
 *
 * Return: 802.15.4 status code of MLME-RESET.confirm
 */
static u8 mlme_reset_request_sync(
        u8    set_default_pib,
        void *device_ref
)
{
        u8 status;
        struct mac_message command, response;
        struct spi_device *spi = device_ref;

        command.command_id = SPI_MLME_RESET_REQUEST;
        command.length = 1;
        command.pdata.u8param = set_default_pib;

        if (cascoda_api_downstream(
                &command.command_id,
                command.length + 2,
                &response.command_id,
                device_ref)) {
                dev_err(&spi->dev, "cascoda_api_downstream failed\n");
                return MAC_SYSTEM_ERROR;
        }

        if (response.command_id != SPI_MLME_RESET_CONFIRM)
                return MAC_SYSTEM_ERROR;

        status = response.pdata.status;

        /* reset COORD Bit for Channel Filtering as Coordinator */
        if (CA8210_MAC_WORKAROUNDS && set_default_pib && !status) {
                status = tdme_setsfr_request_sync(
                        0,
                        CA8210_SFR_MACCON,
                        0,
                        device_ref
                );
        }

        return status;
}

/**
 * mlme_set_request_sync() - MLME_SET_request/confirm according to API Spec
 * @pib_attribute:        Attribute Number
 * @pib_attribute_index:  Index within Attribute if an Array
 * @pib_attribute_length: Attribute length
 * @pib_attribute_value:  Pointer to Attribute Value
 * @device_ref:           Nondescript pointer to target device
 *
 * Return: 802.15.4 status code of MLME-SET.confirm
 */
static u8 mlme_set_request_sync(
        u8            pib_attribute,
        u8            pib_attribute_index,
        u8            pib_attribute_length,
        const void   *pib_attribute_value,
        void         *device_ref
)
{
        u8 status;
        struct mac_message command, response;

        /* pre-check the validity of pib_attribute values that are not checked
         * in MAC
         */
        if (tdme_checkpibattribute(
                pib_attribute, pib_attribute_length, pib_attribute_value)) {
                return MAC_INVALID_PARAMETER;
        }

        if (pib_attribute == PHY_CURRENT_CHANNEL) {
                status = tdme_channelinit(
                        *((u8 *)pib_attribute_value),
                        device_ref
                );
                if (status)
                        return status;
        }

        if (pib_attribute == PHY_TRANSMIT_POWER) {
                return tdme_settxpower(
                        *((u8 *)pib_attribute_value),
                        device_ref
                );
        }

        command.command_id = SPI_MLME_SET_REQUEST;
        command.length = sizeof(struct mlme_set_request_pset) -
                MAX_ATTRIBUTE_SIZE + pib_attribute_length;
        command.pdata.set_req.pib_attribute = pib_attribute;
        command.pdata.set_req.pib_attribute_index = pib_attribute_index;
        command.pdata.set_req.pib_attribute_length = pib_attribute_length;
        memcpy(
                command.pdata.set_req.pib_attribute_value,
                pib_attribute_value,
                pib_attribute_length
        );

        if (cascoda_api_downstream(
                &command.command_id,
                command.length + 2,
                &response.command_id,
                device_ref)) {
                return MAC_SYSTEM_ERROR;
        }

        if (response.command_id != SPI_MLME_SET_CONFIRM)
                return MAC_SYSTEM_ERROR;

        return response.pdata.status;
}

/**
 * hwme_set_request_sync() - HWME_SET_request/confirm according to API Spec
 * @hw_attribute:        Attribute Number
 * @hw_attribute_length: Attribute length
 * @hw_attribute_value:  Pointer to Attribute Value
 * @device_ref:          Nondescript pointer to target device
 *
 * Return: 802.15.4 status code of HWME-SET.confirm
 */
static u8 hwme_set_request_sync(
        u8           hw_attribute,
        u8           hw_attribute_length,
        u8          *hw_attribute_value,
        void        *device_ref
)
{
        struct mac_message command, response;

        command.command_id = SPI_HWME_SET_REQUEST;
        command.length = 2 + hw_attribute_length;
        command.pdata.hwme_set_req.hw_attribute = hw_attribute;
        command.pdata.hwme_set_req.hw_attribute_length = hw_attribute_length;
        memcpy(
                command.pdata.hwme_set_req.hw_attribute_value,
                hw_attribute_value,
                hw_attribute_length
        );

        if (cascoda_api_downstream(
                &command.command_id,
                command.length + 2,
                &response.command_id,
                device_ref)) {
                return MAC_SYSTEM_ERROR;
        }

        if (response.command_id != SPI_HWME_SET_CONFIRM)
                return MAC_SYSTEM_ERROR;

        return response.pdata.hwme_set_cnf.status;
}

/**
 * hwme_get_request_sync() - HWME_GET_request/confirm according to API Spec
 * @hw_attribute:        Attribute Number
 * @hw_attribute_length: Attribute length
 * @hw_attribute_value:  Pointer to Attribute Value
 * @device_ref:          Nondescript pointer to target device
 *
 * Return: 802.15.4 status code of HWME-GET.confirm
 */
static u8 hwme_get_request_sync(
        u8           hw_attribute,
        u8          *hw_attribute_length,
        u8          *hw_attribute_value,
        void        *device_ref
)
{
        struct mac_message command, response;

        command.command_id = SPI_HWME_GET_REQUEST;
        command.length = 1;
        command.pdata.hwme_get_req.hw_attribute = hw_attribute;

        if (cascoda_api_downstream(
                &command.command_id,
                command.length + 2,
                &response.command_id,
                device_ref)) {
                return MAC_SYSTEM_ERROR;
        }

        if (response.command_id != SPI_HWME_GET_CONFIRM)
                return MAC_SYSTEM_ERROR;

        if (response.pdata.hwme_get_cnf.status == MAC_SUCCESS) {
                *hw_attribute_length =
                        response.pdata.hwme_get_cnf.hw_attribute_length;
                memcpy(
                        hw_attribute_value,
                        response.pdata.hwme_get_cnf.hw_attribute_value,
                        *hw_attribute_length
                );
        }

        return response.pdata.hwme_get_cnf.status;
}

/* Network driver operation */

/**
 * ca8210_async_xmit_complete() - Called to announce that an asynchronous
 *                                transmission has finished
 * @hw:          ieee802154_hw of ca8210 that has finished exchange
 * @msduhandle:  Identifier of transmission that has completed
 * @status:      Returned 802.15.4 status code of the transmission
 *
 * Return: 0 or linux error code
 */
static int ca8210_async_xmit_complete(
        struct ieee802154_hw  *hw,
        u8                     msduhandle,
        u8                     status)
{
        struct ca8210_priv *priv = hw->priv;

        if (priv->nextmsduhandle != msduhandle) {
                dev_err(
                        &priv->spi->dev,
                        "Unexpected msdu_handle on data confirm, Expected %d, got %d\n",
                        priv->nextmsduhandle,
                        msduhandle
                );
                return -EIO;
        }

        priv->async_tx_pending = false;
        priv->nextmsduhandle++;

        if (status) {
                dev_err(
                        &priv->spi->dev,
                        "Link transmission unsuccessful, status = %d\n",
                        status
                );
                if (status != MAC_TRANSACTION_OVERFLOW) {
                        ieee802154_wake_queue(priv->hw);
                        return 0;
                }
        }
        ieee802154_xmit_complete(priv->hw, priv->tx_skb, true);

        return 0;
}

/**
 * ca8210_skb_rx() - Contructs a properly framed socket buffer from a received
 *                   MCPS_DATA_indication
 * @hw:        ieee802154_hw that MCPS_DATA_indication was received by
 * @len:       length of MCPS_DATA_indication
 * @data_ind:  Octet array of MCPS_DATA_indication
 *
 * Called by the spi driver whenever a SAP command is received, this function
 * will ascertain whether the command is of interest to the network driver and
 * take necessary action.
 *
 * Return: 0 or linux error code
 */
static int ca8210_skb_rx(
        struct ieee802154_hw  *hw,
        size_t                 len,
        u8                    *data_ind
)
{
        struct ieee802154_hdr hdr;
        int msdulen;
        int hlen;
        u8 mpdulinkquality = data_ind[23];
        struct sk_buff *skb;
        struct ca8210_priv *priv = hw->priv;

        /* Allocate mtu size buffer for every rx packet */
        skb = dev_alloc_skb(IEEE802154_MTU + sizeof(hdr));
        if (!skb)
                return -ENOMEM;

        skb_reserve(skb, sizeof(hdr));

        msdulen = data_ind[22]; /* msdu_length */
        if (msdulen > IEEE802154_MTU) {
                dev_err(
                        &priv->spi->dev,
                        "received erroneously large msdu length!\n"
                );
                kfree_skb(skb);
                return -EMSGSIZE;
        }
        dev_dbg(&priv->spi->dev, "skb buffer length = %d\n", msdulen);

        if (priv->promiscuous)
                goto copy_payload;

        /* Populate hdr */
        hdr.sec.level = data_ind[29 + msdulen];
        dev_dbg(&priv->spi->dev, "security level: %#03x\n", hdr.sec.level);
        if (hdr.sec.level > 0) {
                hdr.sec.key_id_mode = data_ind[30 + msdulen];
                memcpy(&hdr.sec.extended_src, &data_ind[31 + msdulen], 8);
                hdr.sec.key_id = data_ind[39 + msdulen];
        }
        hdr.source.mode = data_ind[0];
        dev_dbg(&priv->spi->dev, "srcAddrMode: %#03x\n", hdr.source.mode);
        hdr.source.pan_id = *(u16 *)&data_ind[1];
        dev_dbg(&priv->spi->dev, "srcPanId: %#06x\n", hdr.source.pan_id);
        memcpy(&hdr.source.extended_addr, &data_ind[3], 8);
        hdr.dest.mode = data_ind[11];
        dev_dbg(&priv->spi->dev, "dstAddrMode: %#03x\n", hdr.dest.mode);
        hdr.dest.pan_id = *(u16 *)&data_ind[12];
        dev_dbg(&priv->spi->dev, "dstPanId: %#06x\n", hdr.dest.pan_id);
        memcpy(&hdr.dest.extended_addr, &data_ind[14], 8);

        /* Fill in FC implicitly */
        hdr.fc.type = 1; /* Data frame */
        if (hdr.sec.level)
                hdr.fc.security_enabled = 1;
        else
                hdr.fc.security_enabled = 0;
        if (data_ind[1] != data_ind[12] || data_ind[2] != data_ind[13])
                hdr.fc.intra_pan = 1;
        else
                hdr.fc.intra_pan = 0;
        hdr.fc.dest_addr_mode = hdr.dest.mode;
        hdr.fc.source_addr_mode = hdr.source.mode;

        /* Add hdr to front of buffer */
        hlen = ieee802154_hdr_push(skb, &hdr);

        if (hlen < 0) {
                dev_crit(&priv->spi->dev, "failed to push mac hdr onto skb!\n");
                kfree_skb(skb);
                return hlen;
        }

        skb_reset_mac_header(skb);
        skb->mac_len = hlen;

copy_payload:
        /* Add <msdulen> bytes of space to the back of the buffer */
        /* Copy msdu to skb */
        skb_put_data(skb, &data_ind[29], msdulen);

        ieee802154_rx_irqsafe(hw, skb, mpdulinkquality);
        return 0;
}

/**
 * ca8210_net_rx() - Acts upon received SAP commands relevant to the network
 *                   driver
 * @hw:       ieee802154_hw that command was received by
 * @command:  Octet array of received command
 * @len:      length of the received command
 *
 * Called by the spi driver whenever a SAP command is received, this function
 * will ascertain whether the command is of interest to the network driver and
 * take necessary action.
 *
 * Return: 0 or linux error code
 */
static int ca8210_net_rx(struct ieee802154_hw *hw, u8 *command, size_t len)
{
        struct ca8210_priv *priv = hw->priv;
        unsigned long flags;
        u8 status;

        dev_dbg(&priv->spi->dev, "%s: CmdID = %d\n", __func__, command[0]);

        if (command[0] == SPI_MCPS_DATA_INDICATION) {
                /* Received data */
                spin_lock_irqsave(&priv->lock, flags);
                if (command[26] == priv->last_dsn) {
                        dev_dbg(
                                &priv->spi->dev,
                                "DSN %d resend received, ignoring...\n",
                                command[26]
                        );
                        spin_unlock_irqrestore(&priv->lock, flags);
                        return 0;
                }
                priv->last_dsn = command[26];
                spin_unlock_irqrestore(&priv->lock, flags);
                return ca8210_skb_rx(hw, len - 2, command + 2);
        } else if (command[0] == SPI_MCPS_DATA_CONFIRM) {
                status = command[3];
                if (priv->async_tx_pending) {
                        return ca8210_async_xmit_complete(
                                hw,
                                command[2],
                                status
                        );
                }
        }

        return 0;
}

/**
 * ca8210_skb_tx() - Transmits a given socket buffer using the ca8210
 * @skb:         Socket buffer to transmit
 * @msduhandle:  Data identifier to pass to the 802.15.4 MAC
 * @priv:        Pointer to private data section of target ca8210
 *
 * Return: 0 or linux error code
 */
static int ca8210_skb_tx(
        struct sk_buff      *skb,
        u8                   msduhandle,
        struct ca8210_priv  *priv
)
{
        int status;
        struct ieee802154_hdr header = { };
        struct secspec secspec;
        unsigned int mac_len;

        dev_dbg(&priv->spi->dev, "%s called\n", __func__);

        /* Get addressing info from skb - ieee802154 layer creates a full
         * packet
         */
        mac_len = ieee802154_hdr_peek_addrs(skb, &header);

        secspec.security_level = header.sec.level;
        secspec.key_id_mode = header.sec.key_id_mode;
        if (secspec.key_id_mode == 2)
                memcpy(secspec.key_source, &header.sec.short_src, 4);
        else if (secspec.key_id_mode == 3)
                memcpy(secspec.key_source, &header.sec.extended_src, 8);
        secspec.key_index = header.sec.key_id;

        /* Pass to Cascoda API */
        status =  mcps_data_request(
                header.source.mode,
                header.dest.mode,
                header.dest.pan_id,
                (union macaddr *)&header.dest.extended_addr,
                skb->len - mac_len,
                &skb->data[mac_len],
                msduhandle,
                header.fc.ack_request,
                &secspec,
                priv->spi
        );
        return link_to_linux_err(status);
}

/**
 * ca8210_start() - Starts the network driver
 * @hw:  ieee802154_hw of ca8210 being started
 *
 * Return: 0 or linux error code
 */
static int ca8210_start(struct ieee802154_hw *hw)
{
        int status;
        u8 rx_on_when_idle;
        u8 lqi_threshold = 0;
        struct ca8210_priv *priv = hw->priv;

        priv->last_dsn = -1;
        /* Turn receiver on when idle for now just to test rx */
        rx_on_when_idle = 1;
        status = mlme_set_request_sync(
                MAC_RX_ON_WHEN_IDLE,
                0,

                1,
                &rx_on_when_idle,
                priv->spi
        );
        if (status) {
                dev_crit(
                        &priv->spi->dev,
                        "Setting rx_on_when_idle failed, status = %d\n",
                        status
                );
                return link_to_linux_err(status);
        }
        status = hwme_set_request_sync(
                HWME_LQILIMIT,
                1,
                &lqi_threshold,
                priv->spi
        );
        if (status) {
                dev_crit(
                        &priv->spi->dev,
                        "Setting lqilimit failed, status = %d\n",
                        status
                );
                return link_to_linux_err(status);
        }

        return 0;
}

/**
 * ca8210_stop() - Stops the network driver
 * @hw:  ieee802154_hw of ca8210 being stopped
 *
 * Return: 0 or linux error code
 */
static void ca8210_stop(struct ieee802154_hw *hw)
{
}

/**
 * ca8210_xmit_async() - Asynchronously transmits a given socket buffer using
 *                       the ca8210
 * @hw:   ieee802154_hw of ca8210 to transmit from
 * @skb:  Socket buffer to transmit
 *
 * Return: 0 or linux error code
 */
static int ca8210_xmit_async(struct ieee802154_hw *hw, struct sk_buff *skb)
{
        struct ca8210_priv *priv = hw->priv;
        int status;

        dev_dbg(&priv->spi->dev, "calling %s\n", __func__);

        priv->tx_skb = skb;
        priv->async_tx_pending = true;
        status = ca8210_skb_tx(skb, priv->nextmsduhandle, priv);
        return status;
}

/**
 * ca8210_get_ed() - Returns the measured energy on the current channel at this
 *                   instant in time
 * @hw:     ieee802154_hw of target ca8210
 * @level:  Measured Energy Detect level
 *
 * Return: 0 or linux error code
 */
static int ca8210_get_ed(struct ieee802154_hw *hw, u8 *level)
{
        u8 lenvar;
        struct ca8210_priv *priv = hw->priv;

        return link_to_linux_err(
                hwme_get_request_sync(HWME_EDVALUE, &lenvar, level, priv->spi)
        );
}

/**
 * ca8210_set_channel() - Sets the current operating 802.15.4 channel of the
 *                        ca8210
 * @hw:       ieee802154_hw of target ca8210
 * @page:     Channel page to set
 * @channel:  Channel number to set
 *
 * Return: 0 or linux error code
 */
static int ca8210_set_channel(
        struct ieee802154_hw  *hw,
        u8                     page,
        u8                     channel
)
{
        u8 status;
        struct ca8210_priv *priv = hw->priv;

        status = mlme_set_request_sync(
                PHY_CURRENT_CHANNEL,
                0,
                1,
                &channel,
                priv->spi
        );
        if (status) {
                dev_err(
                        &priv->spi->dev,
                        "error setting channel, MLME-SET.confirm status = %d\n",
                        status
                );
        }
        return link_to_linux_err(status);
}

/**
 * ca8210_set_hw_addr_filt() - Sets the address filtering parameters of the
 *                             ca8210
 * @hw:       ieee802154_hw of target ca8210
 * @filt:     Filtering parameters
 * @changed:  Bitmap representing which parameters to change
 *
 * Effectively just sets the actual addressing information identifying this node
 * as all filtering is performed by the ca8210 as detailed in the IEEE 802.15.4
 * 2006 specification.
 *
 * Return: 0 or linux error code
 */
static int ca8210_set_hw_addr_filt(
        struct ieee802154_hw            *hw,
        struct ieee802154_hw_addr_filt  *filt,
        unsigned long                    changed
)
{
        u8 status = 0;
        struct ca8210_priv *priv = hw->priv;

        if (changed & IEEE802154_AFILT_PANID_CHANGED) {
                status = mlme_set_request_sync(
                        MAC_PAN_ID,
                        0,
                        2,
                        &filt->pan_id, priv->spi
                );
                if (status) {
                        dev_err(
                                &priv->spi->dev,
                                "error setting pan id, MLME-SET.confirm status = %d",
                                status
                        );
                        return link_to_linux_err(status);
                }
        }
        if (changed & IEEE802154_AFILT_SADDR_CHANGED) {
                status = mlme_set_request_sync(
                        MAC_SHORT_ADDRESS,
                        0,
                        2,
                        &filt->short_addr, priv->spi
                );
                if (status) {
                        dev_err(
                                &priv->spi->dev,
                                "error setting short address, MLME-SET.confirm status = %d",
                                status
                        );
                        return link_to_linux_err(status);
                }
        }
        if (changed & IEEE802154_AFILT_IEEEADDR_CHANGED) {
                status = mlme_set_request_sync(
                        NS_IEEE_ADDRESS,
                        0,
                        8,
                        &filt->ieee_addr,
                        priv->spi
                );
                if (status) {
                        dev_err(
                                &priv->spi->dev,
                                "error setting ieee address, MLME-SET.confirm status = %d",
                                status
                        );
                        return link_to_linux_err(status);
                }
        }
        /* TODO: Should use MLME_START to set coord bit? */
        return 0;
}

/**
 * ca8210_set_tx_power() - Sets the transmit power of the ca8210
 * @hw:   ieee802154_hw of target ca8210
 * @mbm:  Transmit power in mBm (dBm*100)
 *
 * Return: 0 or linux error code
 */
static int ca8210_set_tx_power(struct ieee802154_hw *hw, s32 mbm)
{
        struct ca8210_priv *priv = hw->priv;

        mbm /= 100;
        return link_to_linux_err(
                mlme_set_request_sync(PHY_TRANSMIT_POWER, 0, 1, &mbm, priv->spi)
        );
}

/**
 * ca8210_set_cca_mode() - Sets the clear channel assessment mode of the ca8210
 * @hw:   ieee802154_hw of target ca8210
 * @cca:  CCA mode to set
 *
 * Return: 0 or linux error code
 */
static int ca8210_set_cca_mode(
        struct ieee802154_hw       *hw,
        const struct wpan_phy_cca  *cca
)
{
        u8 status;
        u8 cca_mode;
        struct ca8210_priv *priv = hw->priv;

        cca_mode = cca->mode & 3;
        if (cca_mode == 3 && cca->opt == NL802154_CCA_OPT_ENERGY_CARRIER_OR) {
                /* cca_mode 0 == CS OR ED, 3 == CS AND ED */
                cca_mode = 0;
        }
        status = mlme_set_request_sync(
                PHY_CCA_MODE,
                0,
                1,
                &cca_mode,
                priv->spi
        );
        if (status) {
                dev_err(
                        &priv->spi->dev,
                        "error setting cca mode, MLME-SET.confirm status = %d",
                        status
                );
        }
        return link_to_linux_err(status);
}

/**
 * ca8210_set_cca_ed_level() - Sets the CCA ED level of the ca8210
 * @hw:     ieee802154_hw of target ca8210
 * @level:  ED level to set (in mbm)
 *
 * Sets the minimum threshold of measured energy above which the ca8210 will
 * back off and retry a transmission.
 *
 * Return: 0 or linux error code
 */
static int ca8210_set_cca_ed_level(struct ieee802154_hw *hw, s32 level)
{
        u8 status;
        u8 ed_threshold = (level / 100) * 2 + 256;
        struct ca8210_priv *priv = hw->priv;

        status = hwme_set_request_sync(
                HWME_EDTHRESHOLD,
                1,
                &ed_threshold,
                priv->spi
        );
        if (status) {
                dev_err(
                        &priv->spi->dev,
                        "error setting ed threshold, HWME-SET.confirm status = %d",
                        status
                );
        }
        return link_to_linux_err(status);
}

/**
 * ca8210_set_csma_params() - Sets the CSMA parameters of the ca8210
 * @hw:       ieee802154_hw of target ca8210
 * @min_be:   Minimum backoff exponent when backing off a transmission
 * @max_be:   Maximum backoff exponent when backing off a transmission
 * @retries:  Number of times to retry after backing off
 *
 * Return: 0 or linux error code
 */
static int ca8210_set_csma_params(
        struct ieee802154_hw  *hw,
        u8                     min_be,
        u8                     max_be,
        u8                     retries
)
{
        u8 status;
        struct ca8210_priv *priv = hw->priv;

        status = mlme_set_request_sync(MAC_MIN_BE, 0, 1, &min_be, priv->spi);
        if (status) {
                dev_err(
                        &priv->spi->dev,
                        "error setting min be, MLME-SET.confirm status = %d",
                        status
                );
                return link_to_linux_err(status);
        }
        status = mlme_set_request_sync(MAC_MAX_BE, 0, 1, &max_be, priv->spi);
        if (status) {
                dev_err(
                        &priv->spi->dev,
                        "error setting max be, MLME-SET.confirm status = %d",
                        status
                );
                return link_to_linux_err(status);
        }
        status = mlme_set_request_sync(
                MAC_MAX_CSMA_BACKOFFS,
                0,
                1,
                &retries,
                priv->spi
        );
        if (status) {
                dev_err(
                        &priv->spi->dev,
                        "error setting max csma backoffs, MLME-SET.confirm status = %d",
                        status
                );
        }
        return link_to_linux_err(status);
}

/**
 * ca8210_set_frame_retries() - Sets the maximum frame retries of the ca8210
 * @hw:       ieee802154_hw of target ca8210
 * @retries:  Number of retries
 *
 * Sets the number of times to retry a transmission if no acknowledgment was
 * was received from the other end when one was requested.
 *
 * Return: 0 or linux error code
 */
static int ca8210_set_frame_retries(struct ieee802154_hw *hw, s8 retries)
{
        u8 status;
        struct ca8210_priv *priv = hw->priv;

        status = mlme_set_request_sync(
                MAC_MAX_FRAME_RETRIES,
                0,
                1,
                &retries,
                priv->spi
        );
        if (status) {
                dev_err(
                        &priv->spi->dev,
                        "error setting frame retries, MLME-SET.confirm status = %d",
                        status
                );
        }
        return link_to_linux_err(status);
}

static int ca8210_set_promiscuous_mode(struct ieee802154_hw *hw, const bool on)
{
        u8 status;
        struct ca8210_priv *priv = hw->priv;

        status = mlme_set_request_sync(
                MAC_PROMISCUOUS_MODE,
                0,
                1,
                (const void *)&on,
                priv->spi
        );
        if (status) {
                dev_err(
                        &priv->spi->dev,
                        "error setting promiscuous mode, MLME-SET.confirm status = %d",
                        status
                );
        } else {
                priv->promiscuous = on;
        }
        return link_to_linux_err(status);
}

static const struct ieee802154_ops ca8210_phy_ops = {
        .start = ca8210_start,
        .stop = ca8210_stop,
        .xmit_async = ca8210_xmit_async,
        .ed = ca8210_get_ed,
        .set_channel = ca8210_set_channel,
        .set_hw_addr_filt = ca8210_set_hw_addr_filt,
        .set_txpower = ca8210_set_tx_power,
        .set_cca_mode = ca8210_set_cca_mode,
        .set_cca_ed_level = ca8210_set_cca_ed_level,
        .set_csma_params = ca8210_set_csma_params,
        .set_frame_retries = ca8210_set_frame_retries,
        .set_promiscuous_mode = ca8210_set_promiscuous_mode
};

/* Test/EVBME Interface */

/**
 * ca8210_test_int_open() - Opens the test interface to the userspace
 * @inodp:  inode representation of file interface
 * @filp:   file interface
 *
 * Return: 0 or linux error code
 */
static int ca8210_test_int_open(struct inode *inodp, struct file *filp)
{
        struct ca8210_priv *priv = inodp->i_private;

        filp->private_data = priv;
        return 0;
}

/**
 * ca8210_test_check_upstream() - Checks a command received from the upstream
 *                                testing interface for required action
 * @buf:        Buffer containing command to check
 * @device_ref: Nondescript pointer to target device
 *
 * Return: 0 or linux error code
 */
static int ca8210_test_check_upstream(u8 *buf, void *device_ref)
{
        int ret;
        u8 response[CA8210_SPI_BUF_SIZE];

        if (buf[0] == SPI_MLME_SET_REQUEST) {
                ret = tdme_checkpibattribute(buf[2], buf[4], buf + 5);
                if (ret) {
                        response[0]  = SPI_MLME_SET_CONFIRM;
                        response[1] = 3;
                        response[2] = MAC_INVALID_PARAMETER;
                        response[3] = buf[2];
                        response[4] = buf[3];
                        if (cascoda_api_upstream)
                                cascoda_api_upstream(response, 5, device_ref);
                        return ret;
                }
        }
        if (buf[0] == SPI_MLME_ASSOCIATE_REQUEST) {
                return tdme_channelinit(buf[2], device_ref);
        } else if (buf[0] == SPI_MLME_START_REQUEST) {
                return tdme_channelinit(buf[4], device_ref);
        } else if (
                (buf[0] == SPI_MLME_SET_REQUEST) &&
                (buf[2] == PHY_CURRENT_CHANNEL)
        ) {
                return tdme_channelinit(buf[5], device_ref);
        } else if (
                (buf[0] == SPI_TDME_SET_REQUEST) &&
                (buf[2] == TDME_CHANNEL)
        ) {
                return tdme_channelinit(buf[4], device_ref);
        } else if (
                (CA8210_MAC_WORKAROUNDS) &&
                (buf[0] == SPI_MLME_RESET_REQUEST) &&
                (buf[2] == 1)
        ) {
                /* reset COORD Bit for Channel Filtering as Coordinator */
                return tdme_setsfr_request_sync(
                        0,
                        CA8210_SFR_MACCON,
                        0,
                        device_ref
                );
        }
        return 0;
} /* End of EVBMECheckSerialCommand() */

/**
 * ca8210_test_int_user_write() - Called by a process in userspace to send a
 *                                message to the ca8210 drivers
 * @filp:    file interface
 * @in_buf:  Buffer containing message to write
 * @len:     length of message
 * @off:     file offset
 *
 * Return: 0 or linux error code
 */
static ssize_t ca8210_test_int_user_write(
        struct file        *filp,
        const char __user  *in_buf,
        size_t              len,
        loff_t             *off
)
{
        int ret;
        struct ca8210_priv *priv = filp->private_data;
        u8 command[CA8210_SPI_BUF_SIZE];

        memset(command, SPI_IDLE, 6);
        if (len > CA8210_SPI_BUF_SIZE || len < 2) {
                dev_warn(
                        &priv->spi->dev,
                        "userspace requested erroneous write length (%zu)\n",
                        len
                );
                return -EBADE;
        }

        ret = copy_from_user(command, in_buf, len);
        if (ret) {
                dev_err(
                        &priv->spi->dev,
                        "%d bytes could not be copied from userspace\n",
                        ret
                );
                return -EIO;
        }
        if (len != command[1] + 2) {
                dev_err(
                        &priv->spi->dev,
                        "write len does not match packet length field\n"
                );
                return -EBADE;
        }

        ret = ca8210_test_check_upstream(command, priv->spi);
        if (ret == 0) {
                ret = ca8210_spi_exchange(
                        command,
                        command[1] + 2,
                        NULL,
                        priv->spi
                );
                if (ret < 0) {
                        /* effectively 0 bytes were written successfully */
                        dev_err(
                                &priv->spi->dev,
                                "spi exchange failed\n"
                        );
                        return ret;
                }
                if (command[0] & SPI_SYN)
                        priv->sync_down++;
        }

        return len;
}

/**
 * ca8210_test_int_user_read() - Called by a process in userspace to read a
 *                               message from the ca8210 drivers
 * @filp:  file interface
 * @buf:   Buffer to write message to
 * @len:   length of message to read (ignored)
 * @offp:  file offset
 *
 * If the O_NONBLOCK flag was set when opening the file then this function will
 * not block, i.e. it will return if the fifo is empty. Otherwise the function
 * will block, i.e. wait until new data arrives.
 *
 * Return: number of bytes read
 */
static ssize_t ca8210_test_int_user_read(
        struct file  *filp,
        char __user  *buf,
        size_t        len,
        loff_t       *offp
)
{
        int i, cmdlen;
        struct ca8210_priv *priv = filp->private_data;
        unsigned char *fifo_buffer;
        unsigned long bytes_not_copied;

        if (filp->f_flags & O_NONBLOCK) {
                /* Non-blocking mode */
                if (kfifo_is_empty(&priv->test.up_fifo))
                        return 0;
        } else {
                /* Blocking mode */
                wait_event_interruptible(
                        priv->test.readq,
                        !kfifo_is_empty(&priv->test.up_fifo)
                );
        }

        if (kfifo_out(&priv->test.up_fifo, &fifo_buffer, 4) != 4) {
                dev_err(
                        &priv->spi->dev,
                        "test_interface: Wrong number of elements popped from upstream fifo\n"
                );
                return 0;
        }
        cmdlen = fifo_buffer[1];
        bytes_not_copied = cmdlen + 2;

        bytes_not_copied = copy_to_user(buf, fifo_buffer, bytes_not_copied);
        if (bytes_not_copied > 0) {
                dev_err(
                        &priv->spi->dev,
                        "%lu bytes could not be copied to user space!\n",
                        bytes_not_copied
                );
        }

        dev_dbg(&priv->spi->dev, "test_interface: Cmd len = %d\n", cmdlen);

        dev_dbg(&priv->spi->dev, "test_interface: Read\n");
        for (i = 0; i < cmdlen + 2; i++)
                dev_dbg(&priv->spi->dev, "%#03x\n", fifo_buffer[i]);

        kfree(fifo_buffer);

        return cmdlen + 2;
}

/**
 * ca8210_test_int_ioctl() - Called by a process in userspace to enact an
 *                           arbitrary action
 * @filp:        file interface
 * @ioctl_num:   which action to enact
 * @ioctl_param: arbitrary parameter for the action
 *
 * Return: status
 */
static long ca8210_test_int_ioctl(
        struct file *filp,
        unsigned int ioctl_num,
        unsigned long ioctl_param
)
{
        struct ca8210_priv *priv = filp->private_data;

        switch (ioctl_num) {
        case CA8210_IOCTL_HARD_RESET:
                ca8210_reset_send(priv->spi, ioctl_param);
                break;
        default:
                break;
        }
        return 0;
}

/**
 * ca8210_test_int_poll() - Called by a process in userspace to determine which
 *                          actions are currently possible for the file
 * @filp:   file interface
 * @ptable: poll table
 *
 * Return: set of poll return flags
 */
static __poll_t ca8210_test_int_poll(
        struct file *filp,
        struct poll_table_struct *ptable
)
{
        __poll_t return_flags = 0;
        struct ca8210_priv *priv = filp->private_data;

        poll_wait(filp, &priv->test.readq, ptable);
        if (!kfifo_is_empty(&priv->test.up_fifo))
                return_flags |= (EPOLLIN | EPOLLRDNORM);
        if (wait_event_interruptible(
                priv->test.readq,
                !kfifo_is_empty(&priv->test.up_fifo))) {
                return EPOLLERR;
        }
        return return_flags;
}

static const struct file_operations test_int_fops = {
        .read =           ca8210_test_int_user_read,
        .write =          ca8210_test_int_user_write,
        .open =           ca8210_test_int_open,
        .release =        NULL,
        .unlocked_ioctl = ca8210_test_int_ioctl,
        .poll =           ca8210_test_int_poll
};

/* Init/Deinit */

/**
 * ca8210_get_platform_data() - Populate a ca8210_platform_data object
 * @spi_device:  Pointer to ca8210 spi device object to get data for
 * @pdata:       Pointer to ca8210_platform_data object to populate
 *
 * Return: 0 or linux error code
 */
static int ca8210_get_platform_data(
        struct spi_device *spi_device,
        struct ca8210_platform_data *pdata
)
{
        int ret = 0;

        if (!spi_device->dev.of_node)
                return -EINVAL;

        pdata->extclockenable = of_property_read_bool(
                spi_device->dev.of_node,
                "extclock-enable"
        );
        if (pdata->extclockenable) {
                ret = of_property_read_u32(
                        spi_device->dev.of_node,
                        "extclock-freq",
                        &pdata->extclockfreq
                );
                if (ret < 0)
                        return ret;

                ret = of_property_read_u32(
                        spi_device->dev.of_node,
                        "extclock-gpio",
                        &pdata->extclockgpio
                );
        }

        return ret;
}

/**
 * ca8210_config_extern_clk() - Configure the external clock provided by the
 *                              ca8210
 * @pdata:  Pointer to ca8210_platform_data containing clock parameters
 * @spi:    Pointer to target ca8210 spi device
 * @on:     True to turn the clock on, false to turn off
 *
 * The external clock is configured with a frequency and output pin taken from
 * the platform data.
 *
 * Return: 0 or linux error code
 */
static int ca8210_config_extern_clk(
        struct ca8210_platform_data *pdata,
        struct spi_device *spi,
        bool on
)
{
        u8 clkparam[2];

        if (on) {
                dev_info(&spi->dev, "Switching external clock on\n");
                switch (pdata->extclockfreq) {
                case SIXTEEN_MHZ:
                        clkparam[0] = 1;
                        break;
                case EIGHT_MHZ:
                        clkparam[0] = 2;
                        break;
                case FOUR_MHZ:
                        clkparam[0] = 3;
                        break;
                case TWO_MHZ:
                        clkparam[0] = 4;
                        break;
                case ONE_MHZ:
                        clkparam[0] = 5;
                        break;
                default:
                        dev_crit(&spi->dev, "Invalid extclock-freq\n");
                        return -EINVAL;
                }
                clkparam[1] = pdata->extclockgpio;
        } else {
                dev_info(&spi->dev, "Switching external clock off\n");
                clkparam[0] = 0; /* off */
                clkparam[1] = 0;
        }
        return link_to_linux_err(
                hwme_set_request_sync(HWME_SYSCLKOUT, 2, clkparam, spi)
        );
}

/**
 * ca8210_register_ext_clock() - Register ca8210's external clock with kernel
 * @spi:  Pointer to target ca8210 spi device
 *
 * Return: 0 or linux error code
 */
static int ca8210_register_ext_clock(struct spi_device *spi)
{
        struct device_node *np = spi->dev.of_node;
        struct ca8210_priv *priv = spi_get_drvdata(spi);
        struct ca8210_platform_data *pdata = spi->dev.platform_data;
        int ret = 0;

        if (!np)
                return -EFAULT;

        priv->clk = clk_register_fixed_rate(
                &spi->dev,
                np->name,
                NULL,
                0,
                pdata->extclockfreq
        );

        if (IS_ERR(priv->clk)) {
                dev_crit(&spi->dev, "Failed to register external clk\n");
                return PTR_ERR(priv->clk);
        }
        ret = of_clk_add_provider(np, of_clk_src_simple_get, priv->clk);
        if (ret) {
                clk_unregister(priv->clk);
                dev_crit(
                        &spi->dev,
                        "Failed to register external clock as clock provider\n"
                );
        } else {
                dev_info(&spi->dev, "External clock set as clock provider\n");
        }

        return ret;
}

/**
 * ca8210_unregister_ext_clock() - Unregister ca8210's external clock with
 *                                 kernel
 * @spi:  Pointer to target ca8210 spi device
 */
static void ca8210_unregister_ext_clock(struct spi_device *spi)
{
        struct ca8210_priv *priv = spi_get_drvdata(spi);

        if (!priv->clk)
                return

        of_clk_del_provider(spi->dev.of_node);
        clk_unregister(priv->clk);
        dev_info(&spi->dev, "External clock unregistered\n");
}

/**
 * ca8210_reset_init() - Initialise the reset input to the ca8210
 * @spi:  Pointer to target ca8210 spi device
 *
 * Return: 0 or linux error code
 */
static int ca8210_reset_init(struct spi_device *spi)
{
        int ret;
        struct ca8210_platform_data *pdata = spi->dev.platform_data;

        pdata->gpio_reset = of_get_named_gpio(
                spi->dev.of_node,
                "reset-gpio",
                0
        );

        ret = gpio_direction_output(pdata->gpio_reset, 1);
        if (ret < 0) {
                dev_crit(
                        &spi->dev,
                        "Reset GPIO %d did not set to output mode\n",
                        pdata->gpio_reset
                );
        }

        return ret;
}

/**
 * ca8210_interrupt_init() - Initialise the irq output from the ca8210
 * @spi:  Pointer to target ca8210 spi device
 *
 * Return: 0 or linux error code
 */
static int ca8210_interrupt_init(struct spi_device *spi)
{
        int ret;
        struct ca8210_platform_data *pdata = spi->dev.platform_data;

        pdata->gpio_irq = of_get_named_gpio(
                spi->dev.of_node,
                "irq-gpio",
                0
        );

        pdata->irq_id = gpio_to_irq(pdata->gpio_irq);
        if (pdata->irq_id < 0) {
                dev_crit(
                        &spi->dev,
                        "Could not get irq for gpio pin %d\n",
                        pdata->gpio_irq
                );
                gpio_free(pdata->gpio_irq);
                return pdata->irq_id;
        }

        ret = request_irq(
                pdata->irq_id,
                ca8210_interrupt_handler,
                IRQF_TRIGGER_FALLING,
                "ca8210-irq",
                spi_get_drvdata(spi)
        );
        if (ret) {
                dev_crit(&spi->dev, "request_irq %d failed\n", pdata->irq_id);
                gpio_unexport(pdata->gpio_irq);
                gpio_free(pdata->gpio_irq);
        }

        return ret;
}

/**
 * ca8210_dev_com_init() - Initialise the spi communication component
 * @priv:  Pointer to private data structure
 *
 * Return: 0 or linux error code
 */
static int ca8210_dev_com_init(struct ca8210_priv *priv)
{
        priv->mlme_workqueue = alloc_ordered_workqueue(
                "MLME work queue",
                WQ_UNBOUND
        );
        if (!priv->mlme_workqueue) {
                dev_crit(&priv->spi->dev, "alloc of mlme_workqueue failed!\n");
                return -ENOMEM;
        }

        priv->irq_workqueue = alloc_ordered_workqueue(
                "ca8210 irq worker",
                WQ_UNBOUND
        );
        if (!priv->irq_workqueue) {
                dev_crit(&priv->spi->dev, "alloc of irq_workqueue failed!\n");
                return -ENOMEM;
        }

        return 0;
}

/**
 * ca8210_dev_com_clear() - Deinitialise the spi communication component
 * @priv:  Pointer to private data structure
 */
static void ca8210_dev_com_clear(struct ca8210_priv *priv)
{
        flush_workqueue(priv->mlme_workqueue);
        destroy_workqueue(priv->mlme_workqueue);
        flush_workqueue(priv->irq_workqueue);
        destroy_workqueue(priv->irq_workqueue);
}

#define CA8210_MAX_TX_POWERS (9)
static const s32 ca8210_tx_powers[CA8210_MAX_TX_POWERS] = {
        800, 700, 600, 500, 400, 300, 200, 100, 0
};

#define CA8210_MAX_ED_LEVELS (21)
static const s32 ca8210_ed_levels[CA8210_MAX_ED_LEVELS] = {
        -10300, -10250, -10200, -10150, -10100, -10050, -10000, -9950, -9900,
        -9850, -9800, -9750, -9700, -9650, -9600, -9550, -9500, -9450, -9400,
        -9350, -9300
};

/**
 * ca8210_hw_setup() - Populate the ieee802154_hw phy attributes with the
 *                     ca8210's defaults
 * @ca8210_hw:  Pointer to ieee802154_hw to populate
 */
static void ca8210_hw_setup(struct ieee802154_hw *ca8210_hw)
{
        /* Support channels 11-26 */
        ca8210_hw->phy->supported.channels[0] = CA8210_VALID_CHANNELS;
        ca8210_hw->phy->supported.tx_powers_size = CA8210_MAX_TX_POWERS;
        ca8210_hw->phy->supported.tx_powers = ca8210_tx_powers;
        ca8210_hw->phy->supported.cca_ed_levels_size = CA8210_MAX_ED_LEVELS;
        ca8210_hw->phy->supported.cca_ed_levels = ca8210_ed_levels;
        ca8210_hw->phy->current_channel = 18;
        ca8210_hw->phy->current_page = 0;
        ca8210_hw->phy->transmit_power = 800;
        ca8210_hw->phy->cca.mode = NL802154_CCA_ENERGY_CARRIER;
        ca8210_hw->phy->cca.opt = NL802154_CCA_OPT_ENERGY_CARRIER_AND;
        ca8210_hw->phy->cca_ed_level = -9800;
        ca8210_hw->phy->symbol_duration = 16;
        ca8210_hw->phy->lifs_period = 40;
        ca8210_hw->phy->sifs_period = 12;
        ca8210_hw->flags =
                IEEE802154_HW_AFILT |
                IEEE802154_HW_OMIT_CKSUM |
                IEEE802154_HW_FRAME_RETRIES |
                IEEE802154_HW_PROMISCUOUS |
                IEEE802154_HW_CSMA_PARAMS;
        ca8210_hw->phy->flags =
                WPAN_PHY_FLAG_TXPOWER |
                WPAN_PHY_FLAG_CCA_ED_LEVEL |
                WPAN_PHY_FLAG_CCA_MODE;
}

/**
 * ca8210_test_interface_init() - Initialise the test file interface
 * @priv:  Pointer to private data structure
 *
 * Provided as an alternative to the standard linux network interface, the test
 * interface exposes a file in the filesystem (ca8210_test) that allows
 * 802.15.4 SAP Commands and Cascoda EVBME commands to be sent directly to
 * the stack.
 *
 * Return: 0 or linux error code

 */
static int ca8210_test_interface_init(struct ca8210_priv *priv)
{
        struct ca8210_test *test = &priv->test;
        char node_name[32];

        snprintf(
                node_name,
                sizeof(node_name),
                "ca8210@%d_%d",
                priv->spi->master->bus_num,
                priv->spi->chip_select
        );

        test->ca8210_dfs_spi_int = debugfs_create_file(
                node_name,
                0600, /* S_IRUSR | S_IWUSR */
                NULL,
                priv,
                &test_int_fops
        );
        if (IS_ERR(test->ca8210_dfs_spi_int)) {
                dev_err(
                        &priv->spi->dev,
                        "Error %ld when creating debugfs node\n",
                        PTR_ERR(test->ca8210_dfs_spi_int)
                );
                return PTR_ERR(test->ca8210_dfs_spi_int);
        }
        debugfs_create_symlink("ca8210", NULL, node_name);
        init_waitqueue_head(&test->readq);
        return kfifo_alloc(
                &test->up_fifo,
                CA8210_TEST_INT_FIFO_SIZE,
                GFP_KERNEL
        );
}

/**
 * ca8210_test_interface_clear() - Deinitialise the test file interface
 * @priv:  Pointer to private data structure
 */
static void ca8210_test_interface_clear(struct ca8210_priv *priv)
{
        struct ca8210_test *test = &priv->test;

        debugfs_remove(test->ca8210_dfs_spi_int);
        kfifo_free(&test->up_fifo);
        dev_info(&priv->spi->dev, "Test interface removed\n");
}

/**
 * ca8210_remove() - Shut down a ca8210 upon being disconnected
 * @priv:  Pointer to private data structure
 *
 * Return: 0 or linux error code
 */
static int ca8210_remove(struct spi_device *spi_device)
{
        struct ca8210_priv *priv;
        struct ca8210_platform_data *pdata;

        dev_info(&spi_device->dev, "Removing ca8210\n");

        pdata = spi_device->dev.platform_data;
        if (pdata) {
                if (pdata->extclockenable) {
                        ca8210_unregister_ext_clock(spi_device);
                        ca8210_config_extern_clk(pdata, spi_device, 0);
                }
                free_irq(pdata->irq_id, spi_device->dev.driver_data);
                kfree(pdata);
                spi_device->dev.platform_data = NULL;
        }
        /* get spi_device private data */
        priv = spi_get_drvdata(spi_device);
        if (priv) {
                dev_info(
                        &spi_device->dev,
                        "sync_down = %d, sync_up = %d\n",
                        priv->sync_down,
                        priv->sync_up
                );
                ca8210_dev_com_clear(spi_device->dev.driver_data);
                if (priv->hw) {
                        if (priv->hw_registered)
                                ieee802154_unregister_hw(priv->hw);
                        ieee802154_free_hw(priv->hw);
                        priv->hw = NULL;
                        dev_info(
                                &spi_device->dev,
                                "Unregistered & freed ieee802154_hw.\n"
                        );
                }
                if (IS_ENABLED(CONFIG_IEEE802154_CA8210_DEBUGFS))
                        ca8210_test_interface_clear(priv);
        }

        return 0;
}

/**
 * ca8210_probe() - Set up a connected ca8210 upon being detected by the system
 * @priv:  Pointer to private data structure
 *
 * Return: 0 or linux error code
 */
static int ca8210_probe(struct spi_device *spi_device)
{
        struct ca8210_priv *priv;
        struct ieee802154_hw *hw;
        struct ca8210_platform_data *pdata;
        int ret;

        dev_info(&spi_device->dev, "Inserting ca8210\n");

        /* allocate ieee802154_hw and private data */
        hw = ieee802154_alloc_hw(sizeof(struct ca8210_priv), &ca8210_phy_ops);
        if (!hw) {
                dev_crit(&spi_device->dev, "ieee802154_alloc_hw failed\n");
                ret = -ENOMEM;
                goto error;
        }

        priv = hw->priv;
        priv->hw = hw;
        priv->spi = spi_device;
        hw->parent = &spi_device->dev;
        spin_lock_init(&priv->lock);
        priv->async_tx_pending = false;
        priv->hw_registered = false;
        priv->sync_up = 0;
        priv->sync_down = 0;
        priv->promiscuous = false;
        priv->retries = 0;
        init_completion(&priv->ca8210_is_awake);
        init_completion(&priv->spi_transfer_complete);
        init_completion(&priv->sync_exchange_complete);
        spi_set_drvdata(priv->spi, priv);
        if (IS_ENABLED(CONFIG_IEEE802154_CA8210_DEBUGFS)) {
                cascoda_api_upstream = ca8210_test_int_driver_write;
                ca8210_test_interface_init(priv);
        } else {
                cascoda_api_upstream = NULL;
        }
        ca8210_hw_setup(hw);
        ieee802154_random_extended_addr(&hw->phy->perm_extended_addr);

        pdata = kmalloc(sizeof(*pdata), GFP_KERNEL);
        if (!pdata) {
                ret = -ENOMEM;
                goto error;
        }

        ret = ca8210_get_platform_data(priv->spi, pdata);
        if (ret) {
                dev_crit(&spi_device->dev, "ca8210_get_platform_data failed\n");
                goto error;
        }
        priv->spi->dev.platform_data = pdata;

        ret = ca8210_dev_com_init(priv);
        if (ret) {
                dev_crit(&spi_device->dev, "ca8210_dev_com_init failed\n");
                goto error;
        }
        ret = ca8210_reset_init(priv->spi);
        if (ret) {
                dev_crit(&spi_device->dev, "ca8210_reset_init failed\n");
                goto error;
        }

        ret = ca8210_interrupt_init(priv->spi);
        if (ret) {
                dev_crit(&spi_device->dev, "ca8210_interrupt_init failed\n");
                goto error;
        }

        msleep(100);

        ca8210_reset_send(priv->spi, 1);

        ret = tdme_chipinit(priv->spi);
        if (ret) {
                dev_crit(&spi_device->dev, "tdme_chipinit failed\n");
                goto error;
        }

        if (pdata->extclockenable) {
                ret = ca8210_config_extern_clk(pdata, priv->spi, 1);
                if (ret) {
                        dev_crit(
                                &spi_device->dev,
                                "ca8210_config_extern_clk failed\n"
                        );
                        goto error;
                }
                ret = ca8210_register_ext_clock(priv->spi);
                if (ret) {
                        dev_crit(
                                &spi_device->dev,
                                "ca8210_register_ext_clock failed\n"
                        );
                        goto error;
                }
        }

        ret = ieee802154_register_hw(hw);
        if (ret) {
                dev_crit(&spi_device->dev, "ieee802154_register_hw failed\n");
                goto error;
        }
        priv->hw_registered = true;

        return 0;
error:
        msleep(100); /* wait for pending spi transfers to complete */
        ca8210_remove(spi_device);
        return link_to_linux_err(ret);
}

static const struct of_device_id ca8210_of_ids[] = {
        {.compatible = "cascoda,ca8210", },
        {},
};
MODULE_DEVICE_TABLE(of, ca8210_of_ids);

static struct spi_driver ca8210_spi_driver = {
        .driver = {
                .name =                 DRIVER_NAME,
                .owner =                THIS_MODULE,
                .of_match_table =       of_match_ptr(ca8210_of_ids),
        },
        .probe  =                       ca8210_probe,
        .remove =                       ca8210_remove
};

module_spi_driver(ca8210_spi_driver);

MODULE_AUTHOR("Harry Morris <h.morris@cascoda.com>");
MODULE_DESCRIPTION("CA-8210 SoftMAC driver");
MODULE_LICENSE("Dual BSD/GPL");
MODULE_VERSION("1.0");