root/drivers/mfd/lp87565.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2017 Texas Instruments Incorporated - https://www.ti.com/
 *
 * Author: Keerthy <j-keerthy@ti.com>
 */

#include <linux/gpio/consumer.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/mfd/core.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/regmap.h>

#include <linux/mfd/lp87565.h>

static const struct regmap_config lp87565_regmap_config = {
        .reg_bits = 8,
        .val_bits = 8,
        .max_register = LP87565_REG_MAX,
};

static const struct mfd_cell lp87565_cells[] = {
        { .name = "lp87565-q1-regulator", },
        { .name = "lp87565-q1-gpio", },
};

static const struct of_device_id of_lp87565_match_table[] = {
        { .compatible = "ti,lp87565", },
        {
                .compatible = "ti,lp87524-q1",
                .data = (void *)LP87565_DEVICE_TYPE_LP87524_Q1,
        },
        {
                .compatible = "ti,lp87565-q1",
                .data = (void *)LP87565_DEVICE_TYPE_LP87565_Q1,
        },
        {
                .compatible = "ti,lp87561-q1",
                .data = (void *)LP87565_DEVICE_TYPE_LP87561_Q1,
        },
        {}
};
MODULE_DEVICE_TABLE(of, of_lp87565_match_table);

static int lp87565_probe(struct i2c_client *client)
{
        struct lp87565 *lp87565;
        int ret;
        unsigned int otpid;

        lp87565 = devm_kzalloc(&client->dev, sizeof(*lp87565), GFP_KERNEL);
        if (!lp87565)
                return -ENOMEM;

        lp87565->dev = &client->dev;

        lp87565->regmap = devm_regmap_init_i2c(client, &lp87565_regmap_config);
        if (IS_ERR(lp87565->regmap)) {
                ret = PTR_ERR(lp87565->regmap);
                dev_err(lp87565->dev,
                        "Failed to initialize register map: %d\n", ret);
                return ret;
        }

        lp87565->reset_gpio = devm_gpiod_get_optional(lp87565->dev, "reset",
                                                      GPIOD_OUT_LOW);
        if (IS_ERR(lp87565->reset_gpio)) {
                ret = PTR_ERR(lp87565->reset_gpio);
                if (ret == -EPROBE_DEFER)
                        return ret;
        }

        if (lp87565->reset_gpio) {
                gpiod_set_value_cansleep(lp87565->reset_gpio, 1);
                /* The minimum assertion time is undocumented, just guess */
                usleep_range(2000, 4000);

                gpiod_set_value_cansleep(lp87565->reset_gpio, 0);
                /* Min 1.2 ms before first I2C transaction */
                usleep_range(1500, 3000);
        }

        ret = regmap_read(lp87565->regmap, LP87565_REG_OTP_REV, &otpid);
        if (ret) {
                dev_err(lp87565->dev, "Failed to read OTP ID\n");
                return ret;
        }

        lp87565->rev = otpid & LP87565_OTP_REV_OTP_ID;
        lp87565->dev_type = (uintptr_t)i2c_get_match_data(client);

        i2c_set_clientdata(client, lp87565);

        return devm_mfd_add_devices(lp87565->dev, PLATFORM_DEVID_AUTO,
                                    lp87565_cells, ARRAY_SIZE(lp87565_cells),
                                    NULL, 0, NULL);
}

static void lp87565_shutdown(struct i2c_client *client)
{
        struct lp87565 *lp87565 = i2c_get_clientdata(client);

        gpiod_set_value_cansleep(lp87565->reset_gpio, 1);
}

static const struct i2c_device_id lp87565_id_table[] = {
        { "lp87565-q1" },
        { }
};
MODULE_DEVICE_TABLE(i2c, lp87565_id_table);

static struct i2c_driver lp87565_driver = {
        .driver = {
                .name   = "lp87565",
                .of_match_table = of_lp87565_match_table,
        },
        .probe = lp87565_probe,
        .shutdown = lp87565_shutdown,
        .id_table = lp87565_id_table,
};
module_i2c_driver(lp87565_driver);

MODULE_AUTHOR("J Keerthy <j-keerthy@ti.com>");
MODULE_DESCRIPTION("lp87565 chip family Multi-Function Device driver");
MODULE_LICENSE("GPL v2");