// SPDX-License-Identifier: GPL-2.0
/*
 * Rockchip RK806 Core (SPI) driver
 *
 * Copyright (c) 2021 Rockchip Electronics Co., Ltd.
 * Copyright (c) 2023 Collabora Ltd.
 *
 * Author: Xu Shengfei <xsf@rock-chips.com>
 * Author: Sebastian Reichel <sebastian.reichel@collabora.com>
 */

#include <linux/interrupt.h>
#include <linux/mfd/core.h>
#include <linux/mfd/rk808.h>
#include <linux/module.h>
#include <linux/regmap.h>
#include <linux/spi/spi.h>

#define RK806_ADDR_SIZE 2
#define RK806_CMD_WITH_SIZE(CMD, VALUE_BYTES) \
        (RK806_CMD_##CMD | RK806_CMD_CRC_DIS | (VALUE_BYTES - 1))

static const struct regmap_range rk806_volatile_ranges[] = {
        regmap_reg_range(RK806_POWER_EN0, RK806_POWER_EN5),
        regmap_reg_range(RK806_DVS_START_CTRL, RK806_INT_MSK1),
};

static const struct regmap_access_table rk806_volatile_table = {
        .yes_ranges = rk806_volatile_ranges,
        .n_yes_ranges = ARRAY_SIZE(rk806_volatile_ranges),
};

static const struct regmap_config rk806_regmap_config_spi = {
        .reg_bits = 16,
        .val_bits = 8,
        .max_register = RK806_BUCK_RSERVE_REG5,
        .cache_type = REGCACHE_MAPLE,
        .volatile_table = &rk806_volatile_table,
};

static int rk806_spi_bus_write(void *context, const void *vdata, size_t count)
{
        struct device *dev = context;
        struct spi_device *spi = to_spi_device(dev);
        struct spi_transfer xfer[2] = { 0 };
        /* data and thus count includes the register address */
        size_t val_size = count - RK806_ADDR_SIZE;
        char cmd;

        if (val_size < 1 || val_size > (RK806_CMD_LEN_MSK + 1))
                return -EINVAL;

        cmd = RK806_CMD_WITH_SIZE(WRITE, val_size);

        xfer[0].tx_buf = &cmd;
        xfer[0].len = sizeof(cmd);
        xfer[1].tx_buf = vdata;
        xfer[1].len = count;

        return spi_sync_transfer(spi, xfer, ARRAY_SIZE(xfer));
}

static int rk806_spi_bus_read(void *context, const void *vreg, size_t reg_size,
                              void *val, size_t val_size)
{
        struct device *dev = context;
        struct spi_device *spi = to_spi_device(dev);
        char txbuf[3] = { 0 };

        if (reg_size != RK806_ADDR_SIZE ||
            val_size < 1 || val_size > (RK806_CMD_LEN_MSK + 1))
                return -EINVAL;

        /* TX buffer contains command byte followed by two address bytes */
        txbuf[0] = RK806_CMD_WITH_SIZE(READ, val_size);
        memcpy(txbuf+1, vreg, reg_size);

        return spi_write_then_read(spi, txbuf, sizeof(txbuf), val, val_size);
}

static const struct regmap_bus rk806_regmap_bus_spi = {
        .write = rk806_spi_bus_write,
        .read = rk806_spi_bus_read,
        .reg_format_endian_default = REGMAP_ENDIAN_LITTLE,
};

static int rk8xx_spi_probe(struct spi_device *spi)
{
        struct regmap *regmap;

        regmap = devm_regmap_init(&spi->dev, &rk806_regmap_bus_spi,
                                  &spi->dev, &rk806_regmap_config_spi);
        if (IS_ERR(regmap))
                return dev_err_probe(&spi->dev, PTR_ERR(regmap),
                                     "Failed to init regmap\n");

        return rk8xx_probe(&spi->dev, RK806_ID, spi->irq, regmap);
}

static const struct of_device_id rk8xx_spi_of_match[] = {
        { .compatible = "rockchip,rk806", },
        { }
};
MODULE_DEVICE_TABLE(of, rk8xx_spi_of_match);

static const struct spi_device_id rk8xx_spi_id_table[] = {
        { "rk806", 0 },
        { }
};
MODULE_DEVICE_TABLE(spi, rk8xx_spi_id_table);

static struct spi_driver rk8xx_spi_driver = {
        .driver         = {
                .name   = "rk8xx-spi",
                .of_match_table = rk8xx_spi_of_match,
        },
        .probe          = rk8xx_spi_probe,
        .id_table       = rk8xx_spi_id_table,
};
module_spi_driver(rk8xx_spi_driver);

MODULE_AUTHOR("Xu Shengfei <xsf@rock-chips.com>");
MODULE_DESCRIPTION("RK8xx SPI PMIC driver");
MODULE_LICENSE("GPL");