/*
 * I2C Link Layer for PN544 HCI based Driver
 *
 * Copyright (C) 2012  Intel Corporation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, see <http://www.gnu.org/licenses/>.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/crc-ccitt.h>
#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/gpio.h>
#include <linux/miscdevice.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/nfc.h>
#include <linux/firmware.h>
#include <linux/unaligned/access_ok.h>
#include <linux/platform_data/pn544.h>

#include <net/nfc/hci.h>
#include <net/nfc/llc.h>
#include <net/nfc/nfc.h>

#include "pn544.h"

#define PN544_I2C_FRAME_HEADROOM 1
#define PN544_I2C_FRAME_TAILROOM 2

/* framing in HCI mode */
#define PN544_HCI_I2C_LLC_LEN           1
#define PN544_HCI_I2C_LLC_CRC           2
#define PN544_HCI_I2C_LLC_LEN_CRC       (PN544_HCI_I2C_LLC_LEN + \
                                         PN544_HCI_I2C_LLC_CRC)
#define PN544_HCI_I2C_LLC_MIN_SIZE      (1 + PN544_HCI_I2C_LLC_LEN_CRC)
#define PN544_HCI_I2C_LLC_MAX_PAYLOAD   29
#define PN544_HCI_I2C_LLC_MAX_SIZE      (PN544_HCI_I2C_LLC_LEN_CRC + 1 + \
                                         PN544_HCI_I2C_LLC_MAX_PAYLOAD)

static struct i2c_device_id pn544_hci_i2c_id_table[] = {
        {"pn544", 0},
        {}
};

MODULE_DEVICE_TABLE(i2c, pn544_hci_i2c_id_table);

#define PN544_HCI_I2C_DRIVER_NAME "pn544_hci_i2c"

/*
 * Exposed through the 4 most significant bytes
 * from the HCI SW_VERSION first byte, a.k.a.
 * SW RomLib.
 */
#define PN544_HW_VARIANT_C2 0xa
#define PN544_HW_VARIANT_C3 0xb

#define PN544_FW_CMD_RESET 0x01
#define PN544_FW_CMD_WRITE 0x08
#define PN544_FW_CMD_CHECK 0x06
#define PN544_FW_CMD_SECURE_WRITE 0x0C
#define PN544_FW_CMD_SECURE_CHUNK_WRITE 0x0D

struct pn544_i2c_fw_frame_write {
        u8 cmd;
        u16 be_length;
        u8 be_dest_addr[3];
        u16 be_datalen;
        u8 data[];
} __packed;

struct pn544_i2c_fw_frame_check {
        u8 cmd;
        u16 be_length;
        u8 be_start_addr[3];
        u16 be_datalen;
        u16 be_crc;
} __packed;

struct pn544_i2c_fw_frame_response {
        u8 status;
        u16 be_length;
} __packed;

struct pn544_i2c_fw_blob {
        u32 be_size;
        u32 be_destaddr;
        u8 data[];
};

struct pn544_i2c_fw_secure_frame {
        u8 cmd;
        u16 be_datalen;
        u8 data[];
} __packed;

struct pn544_i2c_fw_secure_blob {
        u64 header;
        u8 data[];
};

#define PN544_FW_CMD_RESULT_TIMEOUT 0x01
#define PN544_FW_CMD_RESULT_BAD_CRC 0x02
#define PN544_FW_CMD_RESULT_ACCESS_DENIED 0x08
#define PN544_FW_CMD_RESULT_PROTOCOL_ERROR 0x0B
#define PN544_FW_CMD_RESULT_INVALID_PARAMETER 0x11
#define PN544_FW_CMD_RESULT_UNSUPPORTED_COMMAND 0x13
#define PN544_FW_CMD_RESULT_INVALID_LENGTH 0x18
#define PN544_FW_CMD_RESULT_CRYPTOGRAPHIC_ERROR 0x19
#define PN544_FW_CMD_RESULT_VERSION_CONDITIONS_ERROR 0x1D
#define PN544_FW_CMD_RESULT_MEMORY_ERROR 0x20
#define PN544_FW_CMD_RESULT_CHUNK_OK 0x21
#define PN544_FW_CMD_RESULT_WRITE_FAILED 0x74
#define PN544_FW_CMD_RESULT_COMMAND_REJECTED 0xE0
#define PN544_FW_CMD_RESULT_CHUNK_ERROR 0xE6

#define MIN(X, Y) ((X) < (Y) ? (X) : (Y))

#define PN544_FW_WRITE_BUFFER_MAX_LEN 0x9f7
#define PN544_FW_I2C_MAX_PAYLOAD PN544_HCI_I2C_LLC_MAX_SIZE
#define PN544_FW_I2C_WRITE_FRAME_HEADER_LEN 8
#define PN544_FW_I2C_WRITE_DATA_MAX_LEN MIN((PN544_FW_I2C_MAX_PAYLOAD -\
                                         PN544_FW_I2C_WRITE_FRAME_HEADER_LEN),\
                                         PN544_FW_WRITE_BUFFER_MAX_LEN)
#define PN544_FW_SECURE_CHUNK_WRITE_HEADER_LEN 3
#define PN544_FW_SECURE_CHUNK_WRITE_DATA_MAX_LEN (PN544_FW_I2C_MAX_PAYLOAD -\
                        PN544_FW_SECURE_CHUNK_WRITE_HEADER_LEN)
#define PN544_FW_SECURE_FRAME_HEADER_LEN 3
#define PN544_FW_SECURE_BLOB_HEADER_LEN 8

#define FW_WORK_STATE_IDLE 1
#define FW_WORK_STATE_START 2
#define FW_WORK_STATE_WAIT_WRITE_ANSWER 3
#define FW_WORK_STATE_WAIT_CHECK_ANSWER 4
#define FW_WORK_STATE_WAIT_SECURE_WRITE_ANSWER 5

struct pn544_i2c_phy {
        struct i2c_client *i2c_dev;
        struct nfc_hci_dev *hdev;

        unsigned int gpio_en;
        unsigned int gpio_irq;
        unsigned int gpio_fw;
        unsigned int en_polarity;

        u8 hw_variant;

        struct work_struct fw_work;
        int fw_work_state;
        char firmware_name[NFC_FIRMWARE_NAME_MAXSIZE + 1];
        const struct firmware *fw;
        u32 fw_blob_dest_addr;
        size_t fw_blob_size;
        const u8 *fw_blob_data;
        size_t fw_written;
        size_t fw_size;

        int fw_cmd_result;

        int powered;
        int run_mode;

        int hard_fault;         /*
                                 * < 0 if hardware error occured (e.g. i2c err)
                                 * and prevents normal operation.
                                 */
};

#define I2C_DUMP_SKB(info, skb)                                 \
do {                                                            \
        pr_debug("%s:\n", info);                                \
        print_hex_dump(KERN_DEBUG, "i2c: ", DUMP_PREFIX_OFFSET, \
                       16, 1, (skb)->data, (skb)->len, 0);      \
} while (0)

static void pn544_hci_i2c_platform_init(struct pn544_i2c_phy *phy)
{
        int polarity, retry, ret;
        char rset_cmd[] = { 0x05, 0xF9, 0x04, 0x00, 0xC3, 0xE5 };
        int count = sizeof(rset_cmd);

        nfc_info(&phy->i2c_dev->dev, "Detecting nfc_en polarity\n");

        /* Disable fw download */
        gpio_set_value(phy->gpio_fw, 0);

        for (polarity = 0; polarity < 2; polarity++) {
                phy->en_polarity = polarity;
                retry = 3;
                while (retry--) {
                        /* power off */
                        gpio_set_value(phy->gpio_en, !phy->en_polarity);
                        usleep_range(10000, 15000);

                        /* power on */
                        gpio_set_value(phy->gpio_en, phy->en_polarity);
                        usleep_range(10000, 15000);

                        /* send reset */
                        dev_dbg(&phy->i2c_dev->dev, "Sending reset cmd\n");
                        ret = i2c_master_send(phy->i2c_dev, rset_cmd, count);
                        if (ret == count) {
                                nfc_info(&phy->i2c_dev->dev,
                                         "nfc_en polarity : active %s\n",
                                         (polarity == 0 ? "low" : "high"));
                                goto out;
                        }
                }
        }

        nfc_err(&phy->i2c_dev->dev,
                "Could not detect nfc_en polarity, fallback to active high\n");

out:
        gpio_set_value(phy->gpio_en, !phy->en_polarity);
}

static void pn544_hci_i2c_enable_mode(struct pn544_i2c_phy *phy, int run_mode)
{
        gpio_set_value(phy->gpio_fw, run_mode == PN544_FW_MODE ? 1 : 0);
        gpio_set_value(phy->gpio_en, phy->en_polarity);
        usleep_range(10000, 15000);

        phy->run_mode = run_mode;
}

static int pn544_hci_i2c_enable(void *phy_id)
{
        struct pn544_i2c_phy *phy = phy_id;

        pr_info("%s\n", __func__);

        pn544_hci_i2c_enable_mode(phy, PN544_HCI_MODE);

        phy->powered = 1;

        return 0;
}

static void pn544_hci_i2c_disable(void *phy_id)
{
        struct pn544_i2c_phy *phy = phy_id;

        gpio_set_value(phy->gpio_fw, 0);
        gpio_set_value(phy->gpio_en, !phy->en_polarity);
        usleep_range(10000, 15000);

        gpio_set_value(phy->gpio_en, phy->en_polarity);
        usleep_range(10000, 15000);

        gpio_set_value(phy->gpio_en, !phy->en_polarity);
        usleep_range(10000, 15000);

        phy->powered = 0;
}

static void pn544_hci_i2c_add_len_crc(struct sk_buff *skb)
{
        u16 crc;
        int len;

        len = skb->len + 2;
        *skb_push(skb, 1) = len;

        crc = crc_ccitt(0xffff, skb->data, skb->len);
        crc = ~crc;
        *skb_put(skb, 1) = crc & 0xff;
        *skb_put(skb, 1) = crc >> 8;
}

static void pn544_hci_i2c_remove_len_crc(struct sk_buff *skb)
{
        skb_pull(skb, PN544_I2C_FRAME_HEADROOM);
        skb_trim(skb, PN544_I2C_FRAME_TAILROOM);
}

/*
 * Writing a frame must not return the number of written bytes.
 * It must return either zero for success, or <0 for error.
 * In addition, it must not alter the skb
 */
static int pn544_hci_i2c_write(void *phy_id, struct sk_buff *skb)
{
        int r;
        struct pn544_i2c_phy *phy = phy_id;
        struct i2c_client *client = phy->i2c_dev;

        if (phy->hard_fault != 0)
                return phy->hard_fault;

        usleep_range(3000, 6000);

        pn544_hci_i2c_add_len_crc(skb);

        I2C_DUMP_SKB("i2c frame written", skb);

        r = i2c_master_send(client, skb->data, skb->len);

        if (r == -EREMOTEIO) {  /* Retry, chip was in standby */
                usleep_range(6000, 10000);
                r = i2c_master_send(client, skb->data, skb->len);
        }

        if (r >= 0) {
                if (r != skb->len)
                        r = -EREMOTEIO;
                else
                        r = 0;
        }

        pn544_hci_i2c_remove_len_crc(skb);

        return r;
}

static int check_crc(u8 *buf, int buflen)
{
        int len;
        u16 crc;

        len = buf[0] + 1;
        crc = crc_ccitt(0xffff, buf, len - 2);
        crc = ~crc;

        if (buf[len - 2] != (crc & 0xff) || buf[len - 1] != (crc >> 8)) {
                pr_err("CRC error 0x%x != 0x%x 0x%x\n",
                       crc, buf[len - 1], buf[len - 2]);
                pr_info("%s: BAD CRC\n", __func__);
                print_hex_dump(KERN_DEBUG, "crc: ", DUMP_PREFIX_NONE,
                               16, 2, buf, buflen, false);
                return -EPERM;
        }
        return 0;
}

/*
 * Reads an shdlc frame and returns it in a newly allocated sk_buff. Guarantees
 * that i2c bus will be flushed and that next read will start on a new frame.
 * returned skb contains only LLC header and payload.
 * returns:
 * -EREMOTEIO : i2c read error (fatal)
 * -EBADMSG : frame was incorrect and discarded
 * -ENOMEM : cannot allocate skb, frame dropped
 */
static int pn544_hci_i2c_read(struct pn544_i2c_phy *phy, struct sk_buff **skb)
{
        int r;
        u8 len;
        u8 tmp[PN544_HCI_I2C_LLC_MAX_SIZE - 1];
        struct i2c_client *client = phy->i2c_dev;

        r = i2c_master_recv(client, &len, 1);
        if (r != 1) {
                nfc_err(&client->dev, "cannot read len byte\n");
                return -EREMOTEIO;
        }

        if ((len < (PN544_HCI_I2C_LLC_MIN_SIZE - 1)) ||
            (len > (PN544_HCI_I2C_LLC_MAX_SIZE - 1))) {
                nfc_err(&client->dev, "invalid len byte\n");
                r = -EBADMSG;
                goto flush;
        }

        *skb = alloc_skb(1 + len, GFP_KERNEL);
        if (*skb == NULL) {
                r = -ENOMEM;
                goto flush;
        }

        *skb_put(*skb, 1) = len;

        r = i2c_master_recv(client, skb_put(*skb, len), len);
        if (r != len) {
                kfree_skb(*skb);
                return -EREMOTEIO;
        }

        I2C_DUMP_SKB("i2c frame read", *skb);

        r = check_crc((*skb)->data, (*skb)->len);
        if (r != 0) {
                kfree_skb(*skb);
                r = -EBADMSG;
                goto flush;
        }

        skb_pull(*skb, 1);
        skb_trim(*skb, (*skb)->len - 2);

        usleep_range(3000, 6000);

        return 0;

flush:
        if (i2c_master_recv(client, tmp, sizeof(tmp)) < 0)
                r = -EREMOTEIO;

        usleep_range(3000, 6000);

        return r;
}

static int pn544_hci_i2c_fw_read_status(struct pn544_i2c_phy *phy)
{
        int r;
        struct pn544_i2c_fw_frame_response response;
        struct i2c_client *client = phy->i2c_dev;

        r = i2c_master_recv(client, (char *) &response, sizeof(response));
        if (r != sizeof(response)) {
                nfc_err(&client->dev, "cannot read fw status\n");
                return -EIO;
        }

        usleep_range(3000, 6000);

        switch (response.status) {
        case 0:
                return 0;
        case PN544_FW_CMD_RESULT_CHUNK_OK:
                return response.status;
        case PN544_FW_CMD_RESULT_TIMEOUT:
                return -ETIMEDOUT;
        case PN544_FW_CMD_RESULT_BAD_CRC:
                return -ENODATA;
        case PN544_FW_CMD_RESULT_ACCESS_DENIED:
                return -EACCES;
        case PN544_FW_CMD_RESULT_PROTOCOL_ERROR:
                return -EPROTO;
        case PN544_FW_CMD_RESULT_INVALID_PARAMETER:
                return -EINVAL;
        case PN544_FW_CMD_RESULT_UNSUPPORTED_COMMAND:
                return -ENOTSUPP;
        case PN544_FW_CMD_RESULT_INVALID_LENGTH:
                return -EBADMSG;
        case PN544_FW_CMD_RESULT_CRYPTOGRAPHIC_ERROR:
                return -ENOKEY;
        case PN544_FW_CMD_RESULT_VERSION_CONDITIONS_ERROR:
                return -EINVAL;
        case PN544_FW_CMD_RESULT_MEMORY_ERROR:
                return -ENOMEM;
        case PN544_FW_CMD_RESULT_COMMAND_REJECTED:
                return -EACCES;
        case PN544_FW_CMD_RESULT_WRITE_FAILED:
        case PN544_FW_CMD_RESULT_CHUNK_ERROR:
                return -EIO;
        default:
                return -EIO;
        }
}

/*
 * Reads an shdlc frame from the chip. This is not as straightforward as it
 * seems. There are cases where we could loose the frame start synchronization.
 * The frame format is len-data-crc, and corruption can occur anywhere while
 * transiting on i2c bus, such that we could read an invalid len.
 * In order to recover synchronization with the next frame, we must be sure
 * to read the real amount of data without using the len byte. We do this by
 * assuming the following:
 * - the chip will always present only one single complete frame on the bus
 *   before triggering the interrupt
 * - the chip will not present a new frame until we have completely read
 *   the previous one (or until we have handled the interrupt).
 * The tricky case is when we read a corrupted len that is less than the real
 * len. We must detect this here in order to determine that we need to flush
 * the bus. This is the reason why we check the crc here.
 */
static irqreturn_t pn544_hci_i2c_irq_thread_fn(int irq, void *phy_id)
{
        struct pn544_i2c_phy *phy = phy_id;
        struct i2c_client *client;
        struct sk_buff *skb = NULL;
        int r;

        if (!phy || irq != phy->i2c_dev->irq) {
                WARN_ON_ONCE(1);
                return IRQ_NONE;
        }

        client = phy->i2c_dev;
        dev_dbg(&client->dev, "IRQ\n");

        if (phy->hard_fault != 0)
                return IRQ_HANDLED;

        if (phy->run_mode == PN544_FW_MODE) {
                phy->fw_cmd_result = pn544_hci_i2c_fw_read_status(phy);
                schedule_work(&phy->fw_work);
        } else {
                r = pn544_hci_i2c_read(phy, &skb);
                if (r == -EREMOTEIO) {
                        phy->hard_fault = r;

                        nfc_hci_recv_frame(phy->hdev, NULL);

                        return IRQ_HANDLED;
                } else if ((r == -ENOMEM) || (r == -EBADMSG)) {
                        return IRQ_HANDLED;
                }

                nfc_hci_recv_frame(phy->hdev, skb);
        }
        return IRQ_HANDLED;
}

static struct nfc_phy_ops i2c_phy_ops = {
        .write = pn544_hci_i2c_write,
        .enable = pn544_hci_i2c_enable,
        .disable = pn544_hci_i2c_disable,
};

static int pn544_hci_i2c_fw_download(void *phy_id, const char *firmware_name,
                                        u8 hw_variant)
{
        struct pn544_i2c_phy *phy = phy_id;

        pr_info("Starting Firmware Download (%s)\n", firmware_name);

        strcpy(phy->firmware_name, firmware_name);

        phy->hw_variant = hw_variant;
        phy->fw_work_state = FW_WORK_STATE_START;

        schedule_work(&phy->fw_work);

        return 0;
}

static void pn544_hci_i2c_fw_work_complete(struct pn544_i2c_phy *phy,
                                           int result)
{
        pr_info("Firmware Download Complete, result=%d\n", result);

        pn544_hci_i2c_disable(phy);

        phy->fw_work_state = FW_WORK_STATE_IDLE;

        if (phy->fw) {
                release_firmware(phy->fw);
                phy->fw = NULL;
        }

        nfc_fw_download_done(phy->hdev->ndev, phy->firmware_name, (u32) -result);
}

static int pn544_hci_i2c_fw_write_cmd(struct i2c_client *client, u32 dest_addr,
                                      const u8 *data, u16 datalen)
{
        u8 frame[PN544_FW_I2C_MAX_PAYLOAD];
        struct pn544_i2c_fw_frame_write *framep;
        u16 params_len;
        int framelen;
        int r;

        if (datalen > PN544_FW_I2C_WRITE_DATA_MAX_LEN)
                datalen = PN544_FW_I2C_WRITE_DATA_MAX_LEN;

        framep = (struct pn544_i2c_fw_frame_write *) frame;

        params_len = sizeof(framep->be_dest_addr) +
                     sizeof(framep->be_datalen) + datalen;
        framelen = params_len + sizeof(framep->cmd) +
                             sizeof(framep->be_length);

        framep->cmd = PN544_FW_CMD_WRITE;

        put_unaligned_be16(params_len, &framep->be_length);

        framep->be_dest_addr[0] = (dest_addr & 0xff0000) >> 16;
        framep->be_dest_addr[1] = (dest_addr & 0xff00) >> 8;
        framep->be_dest_addr[2] = dest_addr & 0xff;

        put_unaligned_be16(datalen, &framep->be_datalen);

        memcpy(framep->data, data, datalen);

        r = i2c_master_send(client, frame, framelen);

        if (r == framelen)
                return datalen;
        else if (r < 0)
                return r;
        else
                return -EIO;
}

static int pn544_hci_i2c_fw_check_cmd(struct i2c_client *client, u32 start_addr,
                                      const u8 *data, u16 datalen)
{
        struct pn544_i2c_fw_frame_check frame;
        int r;
        u16 crc;

        /* calculate local crc for the data we want to check */
        crc = crc_ccitt(0xffff, data, datalen);

        frame.cmd = PN544_FW_CMD_CHECK;

        put_unaligned_be16(sizeof(frame.be_start_addr) +
                           sizeof(frame.be_datalen) + sizeof(frame.be_crc),
                           &frame.be_length);

        /* tell the chip the memory region to which our crc applies */
        frame.be_start_addr[0] = (start_addr & 0xff0000) >> 16;
        frame.be_start_addr[1] = (start_addr & 0xff00) >> 8;
        frame.be_start_addr[2] = start_addr & 0xff;

        put_unaligned_be16(datalen, &frame.be_datalen);

        /*
         * and give our local crc. Chip will calculate its own crc for the
         * region and compare with ours.
         */
        put_unaligned_be16(crc, &frame.be_crc);

        r = i2c_master_send(client, (const char *) &frame, sizeof(frame));

        if (r == sizeof(frame))
                return 0;
        else if (r < 0)
                return r;
        else
                return -EIO;
}

static int pn544_hci_i2c_fw_write_chunk(struct pn544_i2c_phy *phy)
{
        int r;

        r = pn544_hci_i2c_fw_write_cmd(phy->i2c_dev,
                                       phy->fw_blob_dest_addr + phy->fw_written,
                                       phy->fw_blob_data + phy->fw_written,
                                       phy->fw_blob_size - phy->fw_written);
        if (r < 0)
                return r;

        phy->fw_written += r;
        phy->fw_work_state = FW_WORK_STATE_WAIT_WRITE_ANSWER;

        return 0;
}

static int pn544_hci_i2c_fw_secure_write_frame_cmd(struct pn544_i2c_phy *phy,
                                        const u8 *data, u16 datalen)
{
        u8 buf[PN544_FW_I2C_MAX_PAYLOAD];
        struct pn544_i2c_fw_secure_frame *chunk;
        int chunklen;
        int r;

        if (datalen > PN544_FW_SECURE_CHUNK_WRITE_DATA_MAX_LEN)
                datalen = PN544_FW_SECURE_CHUNK_WRITE_DATA_MAX_LEN;

        chunk = (struct pn544_i2c_fw_secure_frame *) buf;

        chunk->cmd = PN544_FW_CMD_SECURE_CHUNK_WRITE;

        put_unaligned_be16(datalen, &chunk->be_datalen);

        memcpy(chunk->data, data, datalen);

        chunklen = sizeof(chunk->cmd) + sizeof(chunk->be_datalen) + datalen;

        r = i2c_master_send(phy->i2c_dev, buf, chunklen);

        if (r == chunklen)
                return datalen;
        else if (r < 0)
                return r;
        else
                return -EIO;

}

static int pn544_hci_i2c_fw_secure_write_frame(struct pn544_i2c_phy *phy)
{
        struct pn544_i2c_fw_secure_frame *framep;
        int r;

        framep = (struct pn544_i2c_fw_secure_frame *) phy->fw_blob_data;
        if (phy->fw_written == 0)
                phy->fw_blob_size = get_unaligned_be16(&framep->be_datalen)
                                + PN544_FW_SECURE_FRAME_HEADER_LEN;

        /* Only secure write command can be chunked*/
        if (phy->fw_blob_size > PN544_FW_I2C_MAX_PAYLOAD &&
                        framep->cmd != PN544_FW_CMD_SECURE_WRITE)
                return -EINVAL;

        /* The firmware also have other commands, we just send them directly */
        if (phy->fw_blob_size < PN544_FW_I2C_MAX_PAYLOAD) {
                r = i2c_master_send(phy->i2c_dev,
                        (const char *) phy->fw_blob_data, phy->fw_blob_size);

                if (r == phy->fw_blob_size)
                        goto exit;
                else if (r < 0)
                        return r;
                else
                        return -EIO;
        }

        r = pn544_hci_i2c_fw_secure_write_frame_cmd(phy,
                                       phy->fw_blob_data + phy->fw_written,
                                       phy->fw_blob_size - phy->fw_written);
        if (r < 0)
                return r;

exit:
        phy->fw_written += r;
        phy->fw_work_state = FW_WORK_STATE_WAIT_SECURE_WRITE_ANSWER;

        /* SW reset command will not trig any response from PN544 */
        if (framep->cmd == PN544_FW_CMD_RESET) {
                pn544_hci_i2c_enable_mode(phy, PN544_FW_MODE);
                phy->fw_cmd_result = 0;
                schedule_work(&phy->fw_work);
        }

        return 0;
}

static void pn544_hci_i2c_fw_work(struct work_struct *work)
{
        struct pn544_i2c_phy *phy = container_of(work, struct pn544_i2c_phy,
                                                fw_work);
        int r;
        struct pn544_i2c_fw_blob *blob;
        struct pn544_i2c_fw_secure_blob *secure_blob;

        switch (phy->fw_work_state) {
        case FW_WORK_STATE_START:
                pn544_hci_i2c_enable_mode(phy, PN544_FW_MODE);

                r = request_firmware(&phy->fw, phy->firmware_name,
                                     &phy->i2c_dev->dev);
                if (r < 0)
                        goto exit_state_start;

                phy->fw_written = 0;

                switch (phy->hw_variant) {
                case PN544_HW_VARIANT_C2:
                        blob = (struct pn544_i2c_fw_blob *) phy->fw->data;
                        phy->fw_blob_size = get_unaligned_be32(&blob->be_size);
                        phy->fw_blob_dest_addr = get_unaligned_be32(
                                                        &blob->be_destaddr);
                        phy->fw_blob_data = blob->data;

                        r = pn544_hci_i2c_fw_write_chunk(phy);
                        break;
                case PN544_HW_VARIANT_C3:
                        secure_blob = (struct pn544_i2c_fw_secure_blob *)
                                                                phy->fw->data;
                        phy->fw_blob_data = secure_blob->data;
                        phy->fw_size = phy->fw->size;
                        r = pn544_hci_i2c_fw_secure_write_frame(phy);
                        break;
                default:
                        r = -ENOTSUPP;
                        break;
                }

exit_state_start:
                if (r < 0)
                        pn544_hci_i2c_fw_work_complete(phy, r);
                break;

        case FW_WORK_STATE_WAIT_WRITE_ANSWER:
                r = phy->fw_cmd_result;
                if (r < 0)
                        goto exit_state_wait_write_answer;

                if (phy->fw_written == phy->fw_blob_size) {
                        r = pn544_hci_i2c_fw_check_cmd(phy->i2c_dev,
                                                       phy->fw_blob_dest_addr,
                                                       phy->fw_blob_data,
                                                       phy->fw_blob_size);
                        if (r < 0)
                                goto exit_state_wait_write_answer;
                        phy->fw_work_state = FW_WORK_STATE_WAIT_CHECK_ANSWER;
                        break;
                }

                r = pn544_hci_i2c_fw_write_chunk(phy);

exit_state_wait_write_answer:
                if (r < 0)
                        pn544_hci_i2c_fw_work_complete(phy, r);
                break;

        case FW_WORK_STATE_WAIT_CHECK_ANSWER:
                r = phy->fw_cmd_result;
                if (r < 0)
                        goto exit_state_wait_check_answer;

                blob = (struct pn544_i2c_fw_blob *) (phy->fw_blob_data +
                       phy->fw_blob_size);
                phy->fw_blob_size = get_unaligned_be32(&blob->be_size);
                if (phy->fw_blob_size != 0) {
                        phy->fw_blob_dest_addr =
                                        get_unaligned_be32(&blob->be_destaddr);
                        phy->fw_blob_data = blob->data;

                        phy->fw_written = 0;
                        r = pn544_hci_i2c_fw_write_chunk(phy);
                }

exit_state_wait_check_answer:
                if (r < 0 || phy->fw_blob_size == 0)
                        pn544_hci_i2c_fw_work_complete(phy, r);
                break;

        case FW_WORK_STATE_WAIT_SECURE_WRITE_ANSWER:
                r = phy->fw_cmd_result;
                if (r < 0)
                        goto exit_state_wait_secure_write_answer;

                if (r == PN544_FW_CMD_RESULT_CHUNK_OK) {
                        r = pn544_hci_i2c_fw_secure_write_frame(phy);
                        goto exit_state_wait_secure_write_answer;
                }

                if (phy->fw_written == phy->fw_blob_size) {
                        secure_blob = (struct pn544_i2c_fw_secure_blob *)
                                (phy->fw_blob_data + phy->fw_blob_size);
                        phy->fw_size -= phy->fw_blob_size +
                                PN544_FW_SECURE_BLOB_HEADER_LEN;
                        if (phy->fw_size >= PN544_FW_SECURE_BLOB_HEADER_LEN
                                        + PN544_FW_SECURE_FRAME_HEADER_LEN) {
                                phy->fw_blob_data = secure_blob->data;

                                phy->fw_written = 0;
                                r = pn544_hci_i2c_fw_secure_write_frame(phy);
                        }
                }

exit_state_wait_secure_write_answer:
                if (r < 0 || phy->fw_size == 0)
                        pn544_hci_i2c_fw_work_complete(phy, r);
                break;

        default:
                break;
        }
}

static int pn544_hci_i2c_probe(struct i2c_client *client,
                               const struct i2c_device_id *id)
{
        struct pn544_i2c_phy *phy;
        struct pn544_nfc_platform_data *pdata;
        int r = 0;

        dev_dbg(&client->dev, "%s\n", __func__);
        dev_dbg(&client->dev, "IRQ: %d\n", client->irq);

        if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
                nfc_err(&client->dev, "Need I2C_FUNC_I2C\n");
                return -ENODEV;
        }

        phy = devm_kzalloc(&client->dev, sizeof(struct pn544_i2c_phy),
                           GFP_KERNEL);
        if (!phy) {
                nfc_err(&client->dev,
                        "Cannot allocate memory for pn544 i2c phy.\n");
                return -ENOMEM;
        }

        INIT_WORK(&phy->fw_work, pn544_hci_i2c_fw_work);
        phy->fw_work_state = FW_WORK_STATE_IDLE;

        phy->i2c_dev = client;
        i2c_set_clientdata(client, phy);

        pdata = client->dev.platform_data;
        if (pdata == NULL) {
                nfc_err(&client->dev, "No platform data\n");
                return -EINVAL;
        }

        if (pdata->request_resources == NULL) {
                nfc_err(&client->dev, "request_resources() missing\n");
                return -EINVAL;
        }

        r = pdata->request_resources(client);
        if (r) {
                nfc_err(&client->dev, "Cannot get platform resources\n");
                return r;
        }

        phy->gpio_en = pdata->get_gpio(NFC_GPIO_ENABLE);
        phy->gpio_fw = pdata->get_gpio(NFC_GPIO_FW_RESET);
        phy->gpio_irq = pdata->get_gpio(NFC_GPIO_IRQ);

        pn544_hci_i2c_platform_init(phy);

        r = request_threaded_irq(client->irq, NULL, pn544_hci_i2c_irq_thread_fn,
                                 IRQF_TRIGGER_RISING | IRQF_ONESHOT,
                                 PN544_HCI_I2C_DRIVER_NAME, phy);
        if (r < 0) {
                nfc_err(&client->dev, "Unable to register IRQ handler\n");
                goto err_rti;
        }

        r = pn544_hci_probe(phy, &i2c_phy_ops, LLC_SHDLC_NAME,
                            PN544_I2C_FRAME_HEADROOM, PN544_I2C_FRAME_TAILROOM,
                            PN544_HCI_I2C_LLC_MAX_PAYLOAD,
                            pn544_hci_i2c_fw_download, &phy->hdev);
        if (r < 0)
                goto err_hci;

        return 0;

err_hci:
        free_irq(client->irq, phy);

err_rti:
        if (pdata->free_resources != NULL)
                pdata->free_resources();

        return r;
}

static int pn544_hci_i2c_remove(struct i2c_client *client)
{
        struct pn544_i2c_phy *phy = i2c_get_clientdata(client);
        struct pn544_nfc_platform_data *pdata = client->dev.platform_data;

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

        cancel_work_sync(&phy->fw_work);
        if (phy->fw_work_state != FW_WORK_STATE_IDLE)
                pn544_hci_i2c_fw_work_complete(phy, -ENODEV);

        pn544_hci_remove(phy->hdev);

        if (phy->powered)
                pn544_hci_i2c_disable(phy);

        free_irq(client->irq, phy);
        if (pdata->free_resources)
                pdata->free_resources();

        return 0;
}

static struct i2c_driver pn544_hci_i2c_driver = {
        .driver = {
                   .name = PN544_HCI_I2C_DRIVER_NAME,
                  },
        .probe = pn544_hci_i2c_probe,
        .id_table = pn544_hci_i2c_id_table,
        .remove = pn544_hci_i2c_remove,
};

module_i2c_driver(pn544_hci_i2c_driver);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION(DRIVER_DESC);