// SPDX-License-Identifier: GPL-2.0
/*
 * Lochnagar I2C bus interface
 *
 * Copyright (c) 2012-2018 Cirrus Logic, Inc. and
 *                         Cirrus Logic International Semiconductor Ltd.
 *
 * Author: Charles Keepax <ckeepax@opensource.cirrus.com>
 */

#include <linux/delay.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/gpio/consumer.h>
#include <linux/i2c.h>
#include <linux/lockdep.h>
#include <linux/mfd/core.h>
#include <linux/mod_devicetable.h>
#include <linux/mutex.h>
#include <linux/of_platform.h>
#include <linux/regmap.h>

#include <linux/mfd/lochnagar.h>
#include <linux/mfd/lochnagar1_regs.h>
#include <linux/mfd/lochnagar2_regs.h>

#define LOCHNAGAR_BOOT_RETRIES          10
#define LOCHNAGAR_BOOT_DELAY_MS         350

#define LOCHNAGAR_CONFIG_POLL_US        10000

static bool lochnagar1_readable_register(struct device *dev, unsigned int reg)
{
        switch (reg) {
        case LOCHNAGAR_SOFTWARE_RESET:
        case LOCHNAGAR_FIRMWARE_ID1...LOCHNAGAR_FIRMWARE_ID2:
        case LOCHNAGAR1_CDC_AIF1_SEL...LOCHNAGAR1_CDC_AIF3_SEL:
        case LOCHNAGAR1_CDC_MCLK1_SEL...LOCHNAGAR1_CDC_MCLK2_SEL:
        case LOCHNAGAR1_CDC_AIF_CTRL1...LOCHNAGAR1_CDC_AIF_CTRL2:
        case LOCHNAGAR1_EXT_AIF_CTRL:
        case LOCHNAGAR1_DSP_AIF1_SEL...LOCHNAGAR1_DSP_AIF2_SEL:
        case LOCHNAGAR1_DSP_CLKIN_SEL:
        case LOCHNAGAR1_DSP_AIF:
        case LOCHNAGAR1_GF_AIF1...LOCHNAGAR1_GF_AIF2:
        case LOCHNAGAR1_PSIA_AIF:
        case LOCHNAGAR1_PSIA1_SEL...LOCHNAGAR1_PSIA2_SEL:
        case LOCHNAGAR1_SPDIF_AIF_SEL:
        case LOCHNAGAR1_GF_AIF3_SEL...LOCHNAGAR1_GF_AIF4_SEL:
        case LOCHNAGAR1_GF_CLKOUT1_SEL:
        case LOCHNAGAR1_GF_AIF1_SEL...LOCHNAGAR1_GF_AIF2_SEL:
        case LOCHNAGAR1_GF_GPIO2...LOCHNAGAR1_GF_GPIO7:
        case LOCHNAGAR1_RST:
        case LOCHNAGAR1_LED1...LOCHNAGAR1_LED2:
        case LOCHNAGAR1_I2C_CTRL:
                return true;
        default:
                return false;
        }
}

static const struct regmap_config lochnagar1_i2c_regmap = {
        .reg_bits = 8,
        .val_bits = 8,
        .reg_format_endian = REGMAP_ENDIAN_BIG,
        .val_format_endian = REGMAP_ENDIAN_BIG,

        .max_register = 0x50,
        .readable_reg = lochnagar1_readable_register,

        .use_single_read = true,
        .use_single_write = true,

        .cache_type = REGCACHE_MAPLE,
};

static const struct reg_sequence lochnagar1_patch[] = {
        { 0x40, 0x0083 },
        { 0x47, 0x0018 },
        { 0x50, 0x0000 },
};

static bool lochnagar2_readable_register(struct device *dev, unsigned int reg)
{
        switch (reg) {
        case LOCHNAGAR_SOFTWARE_RESET:
        case LOCHNAGAR_FIRMWARE_ID1...LOCHNAGAR_FIRMWARE_ID2:
        case LOCHNAGAR2_CDC_AIF1_CTRL...LOCHNAGAR2_CDC_AIF3_CTRL:
        case LOCHNAGAR2_DSP_AIF1_CTRL...LOCHNAGAR2_DSP_AIF2_CTRL:
        case LOCHNAGAR2_PSIA1_CTRL...LOCHNAGAR2_PSIA2_CTRL:
        case LOCHNAGAR2_GF_AIF3_CTRL...LOCHNAGAR2_GF_AIF4_CTRL:
        case LOCHNAGAR2_GF_AIF1_CTRL...LOCHNAGAR2_GF_AIF2_CTRL:
        case LOCHNAGAR2_SPDIF_AIF_CTRL:
        case LOCHNAGAR2_USB_AIF1_CTRL...LOCHNAGAR2_USB_AIF2_CTRL:
        case LOCHNAGAR2_ADAT_AIF_CTRL:
        case LOCHNAGAR2_CDC_MCLK1_CTRL...LOCHNAGAR2_CDC_MCLK2_CTRL:
        case LOCHNAGAR2_DSP_CLKIN_CTRL:
        case LOCHNAGAR2_PSIA1_MCLK_CTRL...LOCHNAGAR2_PSIA2_MCLK_CTRL:
        case LOCHNAGAR2_SPDIF_MCLK_CTRL:
        case LOCHNAGAR2_GF_CLKOUT1_CTRL...LOCHNAGAR2_GF_CLKOUT2_CTRL:
        case LOCHNAGAR2_ADAT_MCLK_CTRL:
        case LOCHNAGAR2_SOUNDCARD_MCLK_CTRL:
        case LOCHNAGAR2_GPIO_FPGA_GPIO1...LOCHNAGAR2_GPIO_FPGA_GPIO6:
        case LOCHNAGAR2_GPIO_CDC_GPIO1...LOCHNAGAR2_GPIO_CDC_GPIO8:
        case LOCHNAGAR2_GPIO_DSP_GPIO1...LOCHNAGAR2_GPIO_DSP_GPIO6:
        case LOCHNAGAR2_GPIO_GF_GPIO2...LOCHNAGAR2_GPIO_GF_GPIO7:
        case LOCHNAGAR2_GPIO_CDC_AIF1_BCLK...LOCHNAGAR2_GPIO_CDC_AIF3_TXDAT:
        case LOCHNAGAR2_GPIO_DSP_AIF1_BCLK...LOCHNAGAR2_GPIO_DSP_AIF2_TXDAT:
        case LOCHNAGAR2_GPIO_PSIA1_BCLK...LOCHNAGAR2_GPIO_PSIA2_TXDAT:
        case LOCHNAGAR2_GPIO_GF_AIF3_BCLK...LOCHNAGAR2_GPIO_GF_AIF4_TXDAT:
        case LOCHNAGAR2_GPIO_GF_AIF1_BCLK...LOCHNAGAR2_GPIO_GF_AIF2_TXDAT:
        case LOCHNAGAR2_GPIO_DSP_UART1_RX...LOCHNAGAR2_GPIO_DSP_UART2_TX:
        case LOCHNAGAR2_GPIO_GF_UART2_RX...LOCHNAGAR2_GPIO_GF_UART2_TX:
        case LOCHNAGAR2_GPIO_USB_UART_RX:
        case LOCHNAGAR2_GPIO_CDC_PDMCLK1...LOCHNAGAR2_GPIO_CDC_PDMDAT2:
        case LOCHNAGAR2_GPIO_CDC_DMICCLK1...LOCHNAGAR2_GPIO_CDC_DMICDAT4:
        case LOCHNAGAR2_GPIO_DSP_DMICCLK1...LOCHNAGAR2_GPIO_DSP_DMICDAT2:
        case LOCHNAGAR2_GPIO_I2C2_SCL...LOCHNAGAR2_GPIO_I2C4_SDA:
        case LOCHNAGAR2_GPIO_DSP_STANDBY:
        case LOCHNAGAR2_GPIO_CDC_MCLK1...LOCHNAGAR2_GPIO_CDC_MCLK2:
        case LOCHNAGAR2_GPIO_DSP_CLKIN:
        case LOCHNAGAR2_GPIO_PSIA1_MCLK...LOCHNAGAR2_GPIO_PSIA2_MCLK:
        case LOCHNAGAR2_GPIO_GF_GPIO1...LOCHNAGAR2_GPIO_GF_GPIO5:
        case LOCHNAGAR2_GPIO_DSP_GPIO20:
        case LOCHNAGAR2_GPIO_CHANNEL1...LOCHNAGAR2_GPIO_CHANNEL16:
        case LOCHNAGAR2_MINICARD_RESETS:
        case LOCHNAGAR2_ANALOGUE_PATH_CTRL1...LOCHNAGAR2_ANALOGUE_PATH_CTRL2:
        case LOCHNAGAR2_COMMS_CTRL4:
        case LOCHNAGAR2_SPDIF_CTRL:
        case LOCHNAGAR2_IMON_CTRL1...LOCHNAGAR2_IMON_CTRL4:
        case LOCHNAGAR2_IMON_DATA1...LOCHNAGAR2_IMON_DATA2:
        case LOCHNAGAR2_POWER_CTRL:
        case LOCHNAGAR2_MICVDD_CTRL1:
        case LOCHNAGAR2_MICVDD_CTRL2:
        case LOCHNAGAR2_VDDCORE_CDC_CTRL1:
        case LOCHNAGAR2_VDDCORE_CDC_CTRL2:
        case LOCHNAGAR2_SOUNDCARD_AIF_CTRL:
                return true;
        default:
                return false;
        }
}

static bool lochnagar2_volatile_register(struct device *dev, unsigned int reg)
{
        switch (reg) {
        case LOCHNAGAR2_GPIO_CHANNEL1...LOCHNAGAR2_GPIO_CHANNEL16:
        case LOCHNAGAR2_ANALOGUE_PATH_CTRL1:
        case LOCHNAGAR2_IMON_CTRL3...LOCHNAGAR2_IMON_CTRL4:
        case LOCHNAGAR2_IMON_DATA1...LOCHNAGAR2_IMON_DATA2:
                return true;
        default:
                return false;
        }
}

static const struct regmap_config lochnagar2_i2c_regmap = {
        .reg_bits = 16,
        .val_bits = 16,
        .reg_format_endian = REGMAP_ENDIAN_BIG,
        .val_format_endian = REGMAP_ENDIAN_BIG,

        .max_register = 0x1F1F,
        .readable_reg = lochnagar2_readable_register,
        .volatile_reg = lochnagar2_volatile_register,

        .cache_type = REGCACHE_MAPLE,
};

static const struct reg_sequence lochnagar2_patch[] = {
        { 0x00EE, 0x0000 },
};

struct lochnagar_config {
        int id;
        const char * const name;
        enum lochnagar_type type;
        const struct regmap_config *regmap;
        const struct reg_sequence *patch;
        int npatch;
};

static struct lochnagar_config lochnagar_configs[] = {
        {
                .id = 0x50,
                .name = "lochnagar1",
                .type = LOCHNAGAR1,
                .regmap = &lochnagar1_i2c_regmap,
                .patch = lochnagar1_patch,
                .npatch = ARRAY_SIZE(lochnagar1_patch),
        },
        {
                .id = 0xCB58,
                .name = "lochnagar2",
                .type = LOCHNAGAR2,
                .regmap = &lochnagar2_i2c_regmap,
                .patch = lochnagar2_patch,
                .npatch = ARRAY_SIZE(lochnagar2_patch),
        },
};

static const struct of_device_id lochnagar_of_match[] = {
        { .compatible = "cirrus,lochnagar1", .data = &lochnagar_configs[0] },
        { .compatible = "cirrus,lochnagar2", .data = &lochnagar_configs[1] },
        {},
};

static int lochnagar_wait_for_boot(struct regmap *regmap, unsigned int *id)
{
        int i, ret;

        for (i = 0; i < LOCHNAGAR_BOOT_RETRIES; ++i) {
                msleep(LOCHNAGAR_BOOT_DELAY_MS);

                /* The reset register will return the device ID when read */
                ret = regmap_read(regmap, LOCHNAGAR_SOFTWARE_RESET, id);
                if (!ret)
                        return ret;
        }

        return -ETIMEDOUT;
}

/**
 * lochnagar_update_config - Synchronise the boards analogue configuration to
 *                           the hardware.
 *
 * @lochnagar: A pointer to the primary core data structure.
 *
 * Return: Zero on success or an appropriate negative error code on failure.
 */
int lochnagar_update_config(struct lochnagar *lochnagar)
{
        struct regmap *regmap = lochnagar->regmap;
        unsigned int done = LOCHNAGAR2_ANALOGUE_PATH_UPDATE_STS_MASK;
        int timeout_ms = LOCHNAGAR_BOOT_DELAY_MS * LOCHNAGAR_BOOT_RETRIES;
        unsigned int val = 0;
        int ret;

        lockdep_assert_held(&lochnagar->analogue_config_lock);

        if (lochnagar->type != LOCHNAGAR2)
                return 0;

        /*
         * Toggle the ANALOGUE_PATH_UPDATE bit and wait for the device to
         * acknowledge that any outstanding changes to the analogue
         * configuration have been applied.
         */
        ret = regmap_write(regmap, LOCHNAGAR2_ANALOGUE_PATH_CTRL1, 0);
        if (ret < 0)
                return ret;

        ret = regmap_write(regmap, LOCHNAGAR2_ANALOGUE_PATH_CTRL1,
                           LOCHNAGAR2_ANALOGUE_PATH_UPDATE_MASK);
        if (ret < 0)
                return ret;

        ret = regmap_read_poll_timeout(regmap,
                                       LOCHNAGAR2_ANALOGUE_PATH_CTRL1, val,
                                       (val & done), LOCHNAGAR_CONFIG_POLL_US,
                                       timeout_ms * 1000);
        if (ret < 0)
                return ret;

        return 0;
}
EXPORT_SYMBOL_GPL(lochnagar_update_config);

static int lochnagar_i2c_probe(struct i2c_client *i2c)
{
        struct device *dev = &i2c->dev;
        const struct lochnagar_config *config = NULL;
        struct lochnagar *lochnagar;
        struct gpio_desc *reset, *present;
        unsigned int val;
        unsigned int firmwareid;
        unsigned int devid, rev;
        int ret;

        lochnagar = devm_kzalloc(dev, sizeof(*lochnagar), GFP_KERNEL);
        if (!lochnagar)
                return -ENOMEM;

        config = i2c_get_match_data(i2c);

        lochnagar->dev = dev;
        mutex_init(&lochnagar->analogue_config_lock);

        dev_set_drvdata(dev, lochnagar);

        reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
        if (IS_ERR(reset)) {
                ret = PTR_ERR(reset);
                dev_err(dev, "Failed to get reset GPIO: %d\n", ret);
                return ret;
        }

        present = devm_gpiod_get_optional(dev, "present", GPIOD_OUT_HIGH);
        if (IS_ERR(present)) {
                ret = PTR_ERR(present);
                dev_err(dev, "Failed to get present GPIO: %d\n", ret);
                return ret;
        }

        /* Leave the Lochnagar in reset for a reasonable amount of time */
        msleep(20);

        /* Bring Lochnagar out of reset */
        gpiod_set_value_cansleep(reset, 1);

        /* Identify Lochnagar */
        lochnagar->type = config->type;

        lochnagar->regmap = devm_regmap_init_i2c(i2c, config->regmap);
        if (IS_ERR(lochnagar->regmap)) {
                ret = PTR_ERR(lochnagar->regmap);
                dev_err(dev, "Failed to allocate register map: %d\n", ret);
                return ret;
        }

        /* Wait for Lochnagar to boot */
        ret = lochnagar_wait_for_boot(lochnagar->regmap, &val);
        if (ret < 0) {
                dev_err(dev, "Failed to read device ID: %d\n", ret);
                return ret;
        }

        devid = val & LOCHNAGAR_DEVICE_ID_MASK;
        rev = val & LOCHNAGAR_REV_ID_MASK;

        if (devid != config->id) {
                dev_err(dev,
                        "ID does not match %s (expected 0x%x got 0x%x)\n",
                        config->name, config->id, devid);
                return -ENODEV;
        }

        /* Identify firmware */
        ret = regmap_read(lochnagar->regmap, LOCHNAGAR_FIRMWARE_ID1, &val);
        if (ret < 0) {
                dev_err(dev, "Failed to read firmware id 1: %d\n", ret);
                return ret;
        }

        firmwareid = val;

        ret = regmap_read(lochnagar->regmap, LOCHNAGAR_FIRMWARE_ID2, &val);
        if (ret < 0) {
                dev_err(dev, "Failed to read firmware id 2: %d\n", ret);
                return ret;
        }

        firmwareid |= (val << config->regmap->val_bits);

        dev_info(dev, "Found %s (0x%x) revision %u firmware 0x%.6x\n",
                 config->name, devid, rev + 1, firmwareid);

        ret = regmap_register_patch(lochnagar->regmap, config->patch,
                                    config->npatch);
        if (ret < 0) {
                dev_err(dev, "Failed to register patch: %d\n", ret);
                return ret;
        }

        ret = devm_of_platform_populate(dev);
        if (ret < 0) {
                dev_err(dev, "Failed to populate child nodes: %d\n", ret);
                return ret;
        }

        return ret;
}

static struct i2c_driver lochnagar_i2c_driver = {
        .driver = {
                .name = "lochnagar",
                .of_match_table = lochnagar_of_match,
                .suppress_bind_attrs = true,
        },
        .probe = lochnagar_i2c_probe,
};

static int __init lochnagar_i2c_init(void)
{
        int ret;

        ret = i2c_add_driver(&lochnagar_i2c_driver);
        if (ret)
                pr_err("Failed to register Lochnagar driver: %d\n", ret);

        return ret;
}
subsys_initcall(lochnagar_i2c_init);