/*
 * This file is part of wl1271
 *
 * Copyright (C) 2008-2009 Nokia Corporation
 *
 * Contact: Luciano Coelho <luciano.coelho@nokia.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms 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, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA
 *
 */

#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/swab.h>
#include <linux/crc7.h>
#include <linux/spi/spi.h>
#include <linux/wl12xx.h>
#include <linux/platform_device.h>
#include <linux/of_irq.h>
#include <linux/regulator/consumer.h>

#include "wlcore.h"
#include "wl12xx_80211.h"
#include "io.h"

#define WSPI_CMD_READ                 0x40000000
#define WSPI_CMD_WRITE                0x00000000
#define WSPI_CMD_FIXED                0x20000000
#define WSPI_CMD_BYTE_LENGTH          0x1FFE0000
#define WSPI_CMD_BYTE_LENGTH_OFFSET   17
#define WSPI_CMD_BYTE_ADDR            0x0001FFFF

#define WSPI_INIT_CMD_CRC_LEN       5

#define WSPI_INIT_CMD_START         0x00
#define WSPI_INIT_CMD_TX            0x40
/* the extra bypass bit is sampled by the TNET as '1' */
#define WSPI_INIT_CMD_BYPASS_BIT    0x80
#define WSPI_INIT_CMD_FIXEDBUSY_LEN 0x07
#define WSPI_INIT_CMD_EN_FIXEDBUSY  0x80
#define WSPI_INIT_CMD_DIS_FIXEDBUSY 0x00
#define WSPI_INIT_CMD_IOD           0x40
#define WSPI_INIT_CMD_IP            0x20
#define WSPI_INIT_CMD_CS            0x10
#define WSPI_INIT_CMD_WS            0x08
#define WSPI_INIT_CMD_WSPI          0x01
#define WSPI_INIT_CMD_END           0x01

#define WSPI_INIT_CMD_LEN           8

#define HW_ACCESS_WSPI_FIXED_BUSY_LEN \
                ((WL1271_BUSY_WORD_LEN - 4) / sizeof(u32))
#define HW_ACCESS_WSPI_INIT_CMD_MASK  0

/* HW limitation: maximum possible chunk size is 4095 bytes */
#define WSPI_MAX_CHUNK_SIZE    4092

/*
 * wl18xx driver aggregation buffer size is (13 * 4K) compared to
 * (4 * 4K) for wl12xx, so use the larger buffer needed for wl18xx
 */
#define SPI_AGGR_BUFFER_SIZE (13 * SZ_4K)

/* Maximum number of SPI write chunks */
#define WSPI_MAX_NUM_OF_CHUNKS \
        ((SPI_AGGR_BUFFER_SIZE / WSPI_MAX_CHUNK_SIZE) + 1)

static const struct wilink_family_data wl127x_data = {
        .name = "wl127x",
        .nvs_name = "ti-connectivity/wl127x-nvs.bin",
};

static const struct wilink_family_data wl128x_data = {
        .name = "wl128x",
        .nvs_name = "ti-connectivity/wl128x-nvs.bin",
};

static const struct wilink_family_data wl18xx_data = {
        .name = "wl18xx",
        .cfg_name = "ti-connectivity/wl18xx-conf.bin",
        .nvs_name = "ti-connectivity/wl1271-nvs.bin",
};

struct wl12xx_spi_glue {
        struct device *dev;
        struct platform_device *core;
        struct regulator *reg; /* Power regulator */
};

static void wl12xx_spi_reset(struct device *child)
{
        struct wl12xx_spi_glue *glue = dev_get_drvdata(child->parent);
        u8 *cmd;
        struct spi_transfer t;
        struct spi_message m;

        cmd = kzalloc(WSPI_INIT_CMD_LEN, GFP_KERNEL);
        if (!cmd) {
                dev_err(child->parent,
                        "could not allocate cmd for spi reset\n");
                return;
        }

        memset(&t, 0, sizeof(t));
        spi_message_init(&m);

        memset(cmd, 0xff, WSPI_INIT_CMD_LEN);

        t.tx_buf = cmd;
        t.len = WSPI_INIT_CMD_LEN;
        spi_message_add_tail(&t, &m);

        spi_sync(to_spi_device(glue->dev), &m);

        kfree(cmd);
}

static void wl12xx_spi_init(struct device *child)
{
        struct wl12xx_spi_glue *glue = dev_get_drvdata(child->parent);
        struct spi_transfer t;
        struct spi_message m;
        struct spi_device *spi = to_spi_device(glue->dev);
        u8 *cmd = kzalloc(WSPI_INIT_CMD_LEN, GFP_KERNEL);

        if (!cmd) {
                dev_err(child->parent,
                        "could not allocate cmd for spi init\n");
                return;
        }

        memset(&t, 0, sizeof(t));
        spi_message_init(&m);

        /*
         * Set WSPI_INIT_COMMAND
         * the data is being send from the MSB to LSB
         */
        cmd[0] = 0xff;
        cmd[1] = 0xff;
        cmd[2] = WSPI_INIT_CMD_START | WSPI_INIT_CMD_TX;
        cmd[3] = 0;
        cmd[4] = 0;
        cmd[5] = HW_ACCESS_WSPI_INIT_CMD_MASK << 3;
        cmd[5] |= HW_ACCESS_WSPI_FIXED_BUSY_LEN & WSPI_INIT_CMD_FIXEDBUSY_LEN;

        cmd[6] = WSPI_INIT_CMD_IOD | WSPI_INIT_CMD_IP | WSPI_INIT_CMD_CS
                | WSPI_INIT_CMD_WSPI | WSPI_INIT_CMD_WS;

        if (HW_ACCESS_WSPI_FIXED_BUSY_LEN == 0)
                cmd[6] |= WSPI_INIT_CMD_DIS_FIXEDBUSY;
        else
                cmd[6] |= WSPI_INIT_CMD_EN_FIXEDBUSY;

        cmd[7] = crc7_be(0, cmd+2, WSPI_INIT_CMD_CRC_LEN) | WSPI_INIT_CMD_END;

        /*
         * The above is the logical order; it must actually be stored
         * in the buffer byte-swapped.
         */
        __swab32s((u32 *)cmd);
        __swab32s((u32 *)cmd+1);

        t.tx_buf = cmd;
        t.len = WSPI_INIT_CMD_LEN;
        spi_message_add_tail(&t, &m);

        spi_sync(to_spi_device(glue->dev), &m);

        /* Send extra clocks with inverted CS (high). this is required
         * by the wilink family in order to successfully enter WSPI mode.
         */
        spi->mode ^= SPI_CS_HIGH;
        memset(&m, 0, sizeof(m));
        spi_message_init(&m);

        cmd[0] = 0xff;
        cmd[1] = 0xff;
        cmd[2] = 0xff;
        cmd[3] = 0xff;
        __swab32s((u32 *)cmd);

        t.tx_buf = cmd;
        t.len = 4;
        spi_message_add_tail(&t, &m);

        spi_sync(to_spi_device(glue->dev), &m);

        /* Restore chip select configration to normal */
        spi->mode ^= SPI_CS_HIGH;
        kfree(cmd);
}

#define WL1271_BUSY_WORD_TIMEOUT 1000

static int wl12xx_spi_read_busy(struct device *child)
{
        struct wl12xx_spi_glue *glue = dev_get_drvdata(child->parent);
        struct wl1271 *wl = dev_get_drvdata(child);
        struct spi_transfer t[1];
        struct spi_message m;
        u32 *busy_buf;
        int num_busy_bytes = 0;

        /*
         * Read further busy words from SPI until a non-busy word is
         * encountered, then read the data itself into the buffer.
         */

        num_busy_bytes = WL1271_BUSY_WORD_TIMEOUT;
        busy_buf = wl->buffer_busyword;
        while (num_busy_bytes) {
                num_busy_bytes--;
                spi_message_init(&m);
                memset(t, 0, sizeof(t));
                t[0].rx_buf = busy_buf;
                t[0].len = sizeof(u32);
                t[0].cs_change = true;
                spi_message_add_tail(&t[0], &m);
                spi_sync(to_spi_device(glue->dev), &m);

                if (*busy_buf & 0x1)
                        return 0;
        }

        /* The SPI bus is unresponsive, the read failed. */
        dev_err(child->parent, "SPI read busy-word timeout!\n");
        return -ETIMEDOUT;
}

static int __must_check wl12xx_spi_raw_read(struct device *child, int addr,
                                            void *buf, size_t len, bool fixed)
{
        struct wl12xx_spi_glue *glue = dev_get_drvdata(child->parent);
        struct wl1271 *wl = dev_get_drvdata(child);
        struct spi_transfer t[2];
        struct spi_message m;
        u32 *busy_buf;
        u32 *cmd;
        u32 chunk_len;

        while (len > 0) {
                chunk_len = min_t(size_t, WSPI_MAX_CHUNK_SIZE, len);

                cmd = &wl->buffer_cmd;
                busy_buf = wl->buffer_busyword;

                *cmd = 0;
                *cmd |= WSPI_CMD_READ;
                *cmd |= (chunk_len << WSPI_CMD_BYTE_LENGTH_OFFSET) &
                        WSPI_CMD_BYTE_LENGTH;
                *cmd |= addr & WSPI_CMD_BYTE_ADDR;

                if (fixed)
                        *cmd |= WSPI_CMD_FIXED;

                spi_message_init(&m);
                memset(t, 0, sizeof(t));

                t[0].tx_buf = cmd;
                t[0].len = 4;
                t[0].cs_change = true;
                spi_message_add_tail(&t[0], &m);

                /* Busy and non busy words read */
                t[1].rx_buf = busy_buf;
                t[1].len = WL1271_BUSY_WORD_LEN;
                t[1].cs_change = true;
                spi_message_add_tail(&t[1], &m);

                spi_sync(to_spi_device(glue->dev), &m);

                if (!(busy_buf[WL1271_BUSY_WORD_CNT - 1] & 0x1) &&
                    wl12xx_spi_read_busy(child)) {
                        memset(buf, 0, chunk_len);
                        return 0;
                }

                spi_message_init(&m);
                memset(t, 0, sizeof(t));

                t[0].rx_buf = buf;
                t[0].len = chunk_len;
                t[0].cs_change = true;
                spi_message_add_tail(&t[0], &m);

                spi_sync(to_spi_device(glue->dev), &m);

                if (!fixed)
                        addr += chunk_len;
                buf += chunk_len;
                len -= chunk_len;
        }

        return 0;
}

static int __wl12xx_spi_raw_write(struct device *child, int addr,
                                  void *buf, size_t len, bool fixed)
{
        struct wl12xx_spi_glue *glue = dev_get_drvdata(child->parent);
        struct spi_transfer *t;
        struct spi_message m;
        u32 commands[WSPI_MAX_NUM_OF_CHUNKS]; /* 1 command per chunk */
        u32 *cmd;
        u32 chunk_len;
        int i;

        /* SPI write buffers - 2 for each chunk */
        t = kzalloc(sizeof(*t) * 2 * WSPI_MAX_NUM_OF_CHUNKS, GFP_KERNEL);
        if (!t)
                return -ENOMEM;

        WARN_ON(len > SPI_AGGR_BUFFER_SIZE);

        spi_message_init(&m);

        cmd = &commands[0];
        i = 0;
        while (len > 0) {
                chunk_len = min_t(size_t, WSPI_MAX_CHUNK_SIZE, len);

                *cmd = 0;
                *cmd |= WSPI_CMD_WRITE;
                *cmd |= (chunk_len << WSPI_CMD_BYTE_LENGTH_OFFSET) &
                        WSPI_CMD_BYTE_LENGTH;
                *cmd |= addr & WSPI_CMD_BYTE_ADDR;

                if (fixed)
                        *cmd |= WSPI_CMD_FIXED;

                t[i].tx_buf = cmd;
                t[i].len = sizeof(*cmd);
                spi_message_add_tail(&t[i++], &m);

                t[i].tx_buf = buf;
                t[i].len = chunk_len;
                spi_message_add_tail(&t[i++], &m);

                if (!fixed)
                        addr += chunk_len;
                buf += chunk_len;
                len -= chunk_len;
                cmd++;
        }

        spi_sync(to_spi_device(glue->dev), &m);

        kfree(t);
        return 0;
}

static int __must_check wl12xx_spi_raw_write(struct device *child, int addr,
                                             void *buf, size_t len, bool fixed)
{
        /* The ELP wakeup write may fail the first time due to internal
         * hardware latency. It is safer to send the wakeup command twice to
         * avoid unexpected failures.
         */
        if (addr == HW_ACCESS_ELP_CTRL_REG)
                __wl12xx_spi_raw_write(child, addr, buf, len, fixed);

        return __wl12xx_spi_raw_write(child, addr, buf, len, fixed);
}

/**
 * wl12xx_spi_set_power - power on/off the wl12xx unit
 * @child: wl12xx device handle.
 * @enable: true/false to power on/off the unit.
 *
 * use the WiFi enable regulator to enable/disable the WiFi unit.
 */
static int wl12xx_spi_set_power(struct device *child, bool enable)
{
        int ret = 0;
        struct wl12xx_spi_glue *glue = dev_get_drvdata(child->parent);

        WARN_ON(!glue->reg);

        /* Update regulator state */
        if (enable) {
                ret = regulator_enable(glue->reg);
                if (ret)
                        dev_err(child, "Power enable failure\n");
        } else {
                ret =  regulator_disable(glue->reg);
                if (ret)
                        dev_err(child, "Power disable failure\n");
        }

        return ret;
}

/**
 * wl12xx_spi_set_block_size
 *
 * This function is not needed for spi mode, but need to be present.
 * Without it defined the wlcore fallback to use the wrong packet
 * allignment on tx.
 */
static void wl12xx_spi_set_block_size(struct device *child,
                                      unsigned int blksz)
{
}

static struct wl1271_if_operations spi_ops = {
        .read           = wl12xx_spi_raw_read,
        .write          = wl12xx_spi_raw_write,
        .reset          = wl12xx_spi_reset,
        .init           = wl12xx_spi_init,
        .power          = wl12xx_spi_set_power,
        .set_block_size = wl12xx_spi_set_block_size,
};

static const struct of_device_id wlcore_spi_of_match_table[] = {
        { .compatible = "ti,wl1271", .data = &wl127x_data},
        { .compatible = "ti,wl1273", .data = &wl127x_data},
        { .compatible = "ti,wl1281", .data = &wl128x_data},
        { .compatible = "ti,wl1283", .data = &wl128x_data},
        { .compatible = "ti,wl1285", .data = &wl128x_data},
        { .compatible = "ti,wl1801", .data = &wl18xx_data},
        { .compatible = "ti,wl1805", .data = &wl18xx_data},
        { .compatible = "ti,wl1807", .data = &wl18xx_data},
        { .compatible = "ti,wl1831", .data = &wl18xx_data},
        { .compatible = "ti,wl1835", .data = &wl18xx_data},
        { .compatible = "ti,wl1837", .data = &wl18xx_data},
        { }
};
MODULE_DEVICE_TABLE(of, wlcore_spi_of_match_table);

/**
 * wlcore_probe_of - DT node parsing.
 * @spi: SPI slave device parameters.
 * @res: resource parameters.
 * @glue: wl12xx SPI bus to slave device glue parameters.
 * @pdev_data: wlcore device parameters
 */
static int wlcore_probe_of(struct spi_device *spi, struct wl12xx_spi_glue *glue,
                           struct wlcore_platdev_data *pdev_data)
{
        struct device_node *dt_node = spi->dev.of_node;
        const struct of_device_id *of_id;

        of_id = of_match_node(wlcore_spi_of_match_table, dt_node);
        if (!of_id)
                return -ENODEV;

        pdev_data->family = of_id->data;
        dev_info(&spi->dev, "selected chip family is %s\n",
                 pdev_data->family->name);

        if (of_find_property(dt_node, "clock-xtal", NULL))
                pdev_data->ref_clock_xtal = true;

        /* optional clock frequency params */
        of_property_read_u32(dt_node, "ref-clock-frequency",
                             &pdev_data->ref_clock_freq);
        of_property_read_u32(dt_node, "tcxo-clock-frequency",
                             &pdev_data->tcxo_clock_freq);

        return 0;
}

static int wl1271_probe(struct spi_device *spi)
{
        struct wl12xx_spi_glue *glue;
        struct wlcore_platdev_data *pdev_data;
        struct resource res[1];
        int ret;

        pdev_data = devm_kzalloc(&spi->dev, sizeof(*pdev_data), GFP_KERNEL);
        if (!pdev_data)
                return -ENOMEM;

        pdev_data->if_ops = &spi_ops;

        glue = devm_kzalloc(&spi->dev, sizeof(*glue), GFP_KERNEL);
        if (!glue) {
                dev_err(&spi->dev, "can't allocate glue\n");
                return -ENOMEM;
        }

        glue->dev = &spi->dev;

        spi_set_drvdata(spi, glue);

        /* This is the only SPI value that we need to set here, the rest
         * comes from the board-peripherals file */
        spi->bits_per_word = 32;

        glue->reg = devm_regulator_get(&spi->dev, "vwlan");
        if (PTR_ERR(glue->reg) == -EPROBE_DEFER)
                return -EPROBE_DEFER;
        if (IS_ERR(glue->reg)) {
                dev_err(glue->dev, "can't get regulator\n");
                return PTR_ERR(glue->reg);
        }

        ret = wlcore_probe_of(spi, glue, pdev_data);
        if (ret) {
                dev_err(glue->dev,
                        "can't get device tree parameters (%d)\n", ret);
                return ret;
        }

        ret = spi_setup(spi);
        if (ret < 0) {
                dev_err(glue->dev, "spi_setup failed\n");
                return ret;
        }

        glue->core = platform_device_alloc(pdev_data->family->name,
                                           PLATFORM_DEVID_AUTO);
        if (!glue->core) {
                dev_err(glue->dev, "can't allocate platform_device\n");
                return -ENOMEM;
        }

        glue->core->dev.parent = &spi->dev;

        memset(res, 0x00, sizeof(res));

        res[0].start = spi->irq;
        res[0].flags = IORESOURCE_IRQ | irq_get_trigger_type(spi->irq);
        res[0].name = "irq";

        ret = platform_device_add_resources(glue->core, res, ARRAY_SIZE(res));
        if (ret) {
                dev_err(glue->dev, "can't add resources\n");
                goto out_dev_put;
        }

        ret = platform_device_add_data(glue->core, pdev_data,
                                       sizeof(*pdev_data));
        if (ret) {
                dev_err(glue->dev, "can't add platform data\n");
                goto out_dev_put;
        }

        ret = platform_device_add(glue->core);
        if (ret) {
                dev_err(glue->dev, "can't register platform device\n");
                goto out_dev_put;
        }

        return 0;

out_dev_put:
        platform_device_put(glue->core);
        return ret;
}

static int wl1271_remove(struct spi_device *spi)
{
        struct wl12xx_spi_glue *glue = spi_get_drvdata(spi);

        platform_device_unregister(glue->core);

        return 0;
}

static struct spi_driver wl1271_spi_driver = {
        .driver = {
                .name           = "wl1271_spi",
                .of_match_table = of_match_ptr(wlcore_spi_of_match_table),
        },

        .probe          = wl1271_probe,
        .remove         = wl1271_remove,
};

module_spi_driver(wl1271_spi_driver);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Luciano Coelho <coelho@ti.com>");
MODULE_AUTHOR("Juuso Oikarinen <juuso.oikarinen@nokia.com>");
MODULE_ALIAS("spi:wl1271");