// SPDX-License-Identifier: GPL-2.0-only
/*
 * This file is part of wl1251
 *
 * Copyright (C) 2008 Nokia Corporation
 */

#include <linux/err.h>
#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/gpio/consumer.h>
#include <linux/of.h>
#include <linux/regulator/consumer.h>

#include "wl1251.h"
#include "reg.h"
#include "spi.h"

struct wl1251_spi {
        struct spi_device *spi;
        struct gpio_desc *power_gpio;
};

static irqreturn_t wl1251_irq(int irq, void *cookie)
{
        struct wl1251 *wl;

        wl1251_debug(DEBUG_IRQ, "IRQ");

        wl = cookie;

        ieee80211_queue_work(wl->hw, &wl->irq_work);

        return IRQ_HANDLED;
}

static void wl1251_spi_reset(struct wl1251 *wl)
{
        struct wl1251_spi *wl_spi = wl->if_priv;
        u8 *cmd;
        struct spi_transfer t;
        struct spi_message m;

        cmd = kzalloc(WSPI_INIT_CMD_LEN, GFP_KERNEL);
        if (!cmd) {
                wl1251_error("could not allocate cmd for spi reset");
                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(wl_spi->spi, &m);

        wl1251_dump(DEBUG_SPI, "spi reset -> ", cmd, WSPI_INIT_CMD_LEN);

        kfree(cmd);
}

static void wl1251_spi_wake(struct wl1251 *wl)
{
        struct wl1251_spi *wl_spi = wl->if_priv;
        struct spi_transfer t;
        struct spi_message m;
        u8 *cmd = kzalloc(WSPI_INIT_CMD_LEN, GFP_KERNEL);

        if (!cmd) {
                wl1251_error("could not allocate cmd for spi init");
                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(wl_spi->spi, &m);

        wl1251_dump(DEBUG_SPI, "spi init -> ", cmd, WSPI_INIT_CMD_LEN);

        kfree(cmd);
}

static void wl1251_spi_reset_wake(struct wl1251 *wl)
{
        wl1251_spi_reset(wl);
        wl1251_spi_wake(wl);
}

static void wl1251_spi_read(struct wl1251 *wl, int addr, void *buf,
                            size_t len)
{
        struct wl1251_spi *wl_spi = wl->if_priv;
        struct spi_transfer t[3];
        struct spi_message m;
        u8 *busy_buf;
        u32 *cmd;

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

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

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

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

        /* Busy and non busy words read */
        t[1].rx_buf = busy_buf;
        t[1].len = WL1251_BUSY_WORD_LEN;
        spi_message_add_tail(&t[1], &m);

        t[2].rx_buf = buf;
        t[2].len = len;
        spi_message_add_tail(&t[2], &m);

        spi_sync(wl_spi->spi, &m);

        /* FIXME: check busy words */

        wl1251_dump(DEBUG_SPI, "spi_read cmd -> ", cmd, sizeof(*cmd));
        wl1251_dump(DEBUG_SPI, "spi_read buf <- ", buf, len);
}

static void wl1251_spi_write(struct wl1251 *wl, int addr, void *buf,
                             size_t len)
{
        struct wl1251_spi *wl_spi = wl->if_priv;
        struct spi_transfer t[2];
        struct spi_message m;
        u32 *cmd;

        cmd = &wl->buffer_cmd;

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

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

        t[0].tx_buf = cmd;
        t[0].len = sizeof(*cmd);
        spi_message_add_tail(&t[0], &m);

        t[1].tx_buf = buf;
        t[1].len = len;
        spi_message_add_tail(&t[1], &m);

        spi_sync(wl_spi->spi, &m);

        wl1251_dump(DEBUG_SPI, "spi_write cmd -> ", cmd, sizeof(*cmd));
        wl1251_dump(DEBUG_SPI, "spi_write buf -> ", buf, len);
}

static void wl1251_spi_enable_irq(struct wl1251 *wl)
{
        return enable_irq(wl->irq);
}

static void wl1251_spi_disable_irq(struct wl1251 *wl)
{
        return disable_irq(wl->irq);
}

static int wl1251_spi_set_power(struct wl1251 *wl, bool enable)
{
        struct wl1251_spi *wl_spi = wl->if_priv;

        if (wl_spi->power_gpio)
                gpiod_set_value_cansleep(wl_spi->power_gpio, enable);

        return 0;
}

static const struct wl1251_if_operations wl1251_spi_ops = {
        .read = wl1251_spi_read,
        .write = wl1251_spi_write,
        .reset = wl1251_spi_reset_wake,
        .enable_irq = wl1251_spi_enable_irq,
        .disable_irq = wl1251_spi_disable_irq,
        .power = wl1251_spi_set_power,
};

static int wl1251_spi_probe(struct spi_device *spi)
{
        struct device_node *np = spi->dev.of_node;
        struct ieee80211_hw *hw;
        struct wl1251_spi *wl_spi;
        struct wl1251 *wl;
        int ret;

        if (!np)
                return -ENODEV;

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

        wl_spi->spi = spi;

        hw = wl1251_alloc_hw();
        if (IS_ERR(hw))
                return PTR_ERR(hw);

        wl = hw->priv;

        SET_IEEE80211_DEV(hw, &spi->dev);
        spi_set_drvdata(spi, wl);
        wl->if_priv = wl_spi;
        wl->if_ops = &wl1251_spi_ops;

        /* 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;

        ret = spi_setup(spi);
        if (ret < 0) {
                wl1251_error("spi_setup failed");
                goto out_free;
        }

        wl->use_eeprom = of_property_read_bool(np, "ti,wl1251-has-eeprom");

        wl_spi->power_gpio = devm_gpiod_get_optional(&spi->dev, "ti,power",
                                                     GPIOD_OUT_LOW);
        ret = PTR_ERR_OR_ZERO(wl_spi->power_gpio);
        if (ret) {
                if (ret != -EPROBE_DEFER)
                        wl1251_error("Failed to request gpio: %d\n", ret);
                goto out_free;
        }

        gpiod_set_consumer_name(wl_spi->power_gpio, "wl1251 power");

        wl->irq = spi->irq;
        if (wl->irq < 0) {
                wl1251_error("irq missing in platform data");
                ret = -ENODEV;
                goto out_free;
        }

        irq_set_status_flags(wl->irq, IRQ_NOAUTOEN);
        ret = devm_request_irq(&spi->dev, wl->irq, wl1251_irq, 0,
                                                        DRIVER_NAME, wl);
        if (ret < 0) {
                wl1251_error("request_irq() failed: %d", ret);
                goto out_free;
        }

        irq_set_irq_type(wl->irq, IRQ_TYPE_EDGE_RISING);

        wl->vio = devm_regulator_get(&spi->dev, "vio");
        if (IS_ERR(wl->vio)) {
                ret = PTR_ERR(wl->vio);
                wl1251_error("vio regulator missing: %d", ret);
                goto out_free;
        }

        ret = regulator_enable(wl->vio);
        if (ret)
                goto out_free;

        ret = wl1251_init_ieee80211(wl);
        if (ret)
                goto disable_regulator;

        return 0;

disable_regulator:
        regulator_disable(wl->vio);
out_free:
        ieee80211_free_hw(hw);

        return ret;
}

static void wl1251_spi_remove(struct spi_device *spi)
{
        struct wl1251 *wl = spi_get_drvdata(spi);

        wl1251_free_hw(wl);
        regulator_disable(wl->vio);
}

static struct spi_driver wl1251_spi_driver = {
        .driver = {
                .name           = DRIVER_NAME,
        },

        .probe          = wl1251_spi_probe,
        .remove         = wl1251_spi_remove,
};

module_spi_driver(wl1251_spi_driver);

MODULE_DESCRIPTION("TI WL1251 SPI helpers");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Kalle Valo <kvalo@adurom.com>");
MODULE_ALIAS("spi:wl1251");