// SPDX-License-Identifier: GPL-2.0-only
/*
 *      LED driver for TI lp3952 controller
 *
 *      Copyright (C) 2016, DAQRI, LLC.
 *      Author: Tony Makkiel <tony.makkiel@daqri.com>
 */

#include <linux/delay.h>
#include <linux/gpio/consumer.h>
#include <linux/i2c.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/leds.h>
#include <linux/leds-lp3952.h>
#include <linux/module.h>
#include <linux/notifier.h>
#include <linux/platform_device.h>
#include <linux/pm.h>
#include <linux/reboot.h>
#include <linux/regmap.h>

static int lp3952_register_write(struct i2c_client *client, u8 reg, u8 val)
{
        int ret;
        struct lp3952_led_array *priv = i2c_get_clientdata(client);

        ret = regmap_write(priv->regmap, reg, val);

        if (ret)
                dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n",
                        __func__, reg, val, ret);
        return ret;
}

static void lp3952_on_off(struct lp3952_led_array *priv,
                          enum lp3952_leds led_id, bool on)
{
        int ret, val;

        dev_dbg(&priv->client->dev, "%s LED %d to %d\n", __func__, led_id, on);

        val = 1 << led_id;
        if (led_id == LP3952_LED_ALL)
                val = LP3952_LED_MASK_ALL;

        ret = regmap_update_bits(priv->regmap, LP3952_REG_LED_CTRL, val,
                                 on ? val : 0);
        if (ret)
                dev_err(&priv->client->dev, "%s, Error %d\n", __func__, ret);
}

/*
 * Using Imax to control brightness. There are 4 possible
 * setting 25, 50, 75 and 100 % of Imax. Possible values are
 * values 0-4. 0 meaning turn off.
 */
static int lp3952_set_brightness(struct led_classdev *cdev,
                                 enum led_brightness value)
{
        unsigned int reg, shift_val;
        struct lp3952_ctrl_hdl *led = container_of(cdev,
                                                   struct lp3952_ctrl_hdl,
                                                   cdev);
        struct lp3952_led_array *priv = (struct lp3952_led_array *)led->priv;

        dev_dbg(cdev->dev, "Brightness request: %d on %d\n", value,
                led->channel);

        if (value == LED_OFF) {
                lp3952_on_off(priv, led->channel, false);
                return 0;
        }

        if (led->channel > LP3952_RED_1) {
                dev_err(cdev->dev, " %s Invalid LED requested", __func__);
                return -EINVAL;
        }

        if (led->channel >= LP3952_BLUE_1) {
                reg = LP3952_REG_RGB1_MAX_I_CTRL;
                shift_val = (led->channel - LP3952_BLUE_1) * 2;
        } else {
                reg = LP3952_REG_RGB2_MAX_I_CTRL;
                shift_val = led->channel * 2;
        }

        /* Enable the LED in case it is not enabled already */
        lp3952_on_off(priv, led->channel, true);

        return regmap_update_bits(priv->regmap, reg, 3 << shift_val,
                                  --value << shift_val);
}

static int lp3952_get_label(struct device *dev, const char *label, char *dest)
{
        int ret;
        const char *str;

        ret = device_property_read_string(dev, label, &str);
        if (ret)
                return ret;

        strscpy(dest, str, LP3952_LABEL_MAX_LEN);
        return 0;
}

static int lp3952_register_led_classdev(struct lp3952_led_array *priv)
{
        int i, acpi_ret, ret = -ENODEV;
        static const char *led_name_hdl[LP3952_LED_ALL] = {
                "blue2",
                "green2",
                "red2",
                "blue1",
                "green1",
                "red1"
        };

        for (i = 0; i < LP3952_LED_ALL; i++) {
                acpi_ret = lp3952_get_label(&priv->client->dev, led_name_hdl[i],
                                            priv->leds[i].name);
                if (acpi_ret)
                        continue;

                priv->leds[i].cdev.name = priv->leds[i].name;
                priv->leds[i].cdev.brightness = LED_OFF;
                priv->leds[i].cdev.max_brightness = LP3952_BRIGHT_MAX;
                priv->leds[i].cdev.brightness_set_blocking =
                                lp3952_set_brightness;
                priv->leds[i].channel = i;
                priv->leds[i].priv = priv;

                ret = devm_led_classdev_register(&priv->client->dev,
                                                 &priv->leds[i].cdev);
                if (ret < 0) {
                        dev_err(&priv->client->dev,
                                "couldn't register LED %s\n",
                                priv->leds[i].cdev.name);
                        break;
                }
        }
        return ret;
}

static int lp3952_set_pattern_gen_cmd(struct lp3952_led_array *priv,
                                      u8 cmd_index, u8 r, u8 g, u8 b,
                                      enum lp3952_tt tt, enum lp3952_cet cet)
{
        int ret;
        struct ptrn_gen_cmd line = {
                {
                        {
                                .r = r,
                                .g = g,
                                .b = b,
                                .cet = cet,
                                .tt = tt
                        }
                }
        };

        if (cmd_index >= LP3952_CMD_REG_COUNT)
                return -EINVAL;

        ret = lp3952_register_write(priv->client,
                                    LP3952_REG_CMD_0 + cmd_index * 2,
                                    line.bytes.msb);
        if (ret)
                return ret;

        return lp3952_register_write(priv->client,
                                      LP3952_REG_CMD_0 + cmd_index * 2 + 1,
                                      line.bytes.lsb);
}

static int lp3952_configure(struct lp3952_led_array *priv)
{
        int ret;

        /* Disable any LEDs on from any previous conf. */
        ret = lp3952_register_write(priv->client, LP3952_REG_LED_CTRL, 0);
        if (ret)
                return ret;

        /* enable rgb patter, loop */
        ret = lp3952_register_write(priv->client, LP3952_REG_PAT_GEN_CTRL,
                                    LP3952_PATRN_LOOP | LP3952_PATRN_GEN_EN);
        if (ret)
                return ret;

        /* Update Bit 6 (Active mode), Select both Led sets, Bit [1:0] */
        ret = lp3952_register_write(priv->client, LP3952_REG_ENABLES,
                                    LP3952_ACTIVE_MODE | LP3952_INT_B00ST_LDR);
        if (ret)
                return ret;

        /* Set Cmd1 for RGB intensity,cmd and transition time */
        return lp3952_set_pattern_gen_cmd(priv, 0, I46, I71, I100, TT0,
                                           CET197);
}

static const struct regmap_config lp3952_regmap = {
        .reg_bits = 8,
        .val_bits = 8,
        .max_register = REG_MAX,
        .cache_type = REGCACHE_MAPLE,
};

static void gpio_set_low_action(void *data)
{
        struct lp3952_led_array *priv = data;

        gpiod_set_value(priv->enable_gpio, 0);
}

static int lp3952_probe(struct i2c_client *client)
{
        int status;
        struct lp3952_led_array *priv;

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

        priv->client = client;

        priv->enable_gpio = devm_gpiod_get(&client->dev, "nrst",
                                           GPIOD_OUT_HIGH);
        if (IS_ERR(priv->enable_gpio)) {
                status = PTR_ERR(priv->enable_gpio);
                dev_err(&client->dev, "Failed to enable gpio: %d\n", status);
                return status;
        }

        status = devm_add_action(&client->dev, gpio_set_low_action, priv);
        if (status)
                return status;

        priv->regmap = devm_regmap_init_i2c(client, &lp3952_regmap);
        if (IS_ERR(priv->regmap)) {
                int err = PTR_ERR(priv->regmap);

                dev_err(&client->dev, "Failed to allocate register map: %d\n",
                        err);
                return err;
        }

        i2c_set_clientdata(client, priv);

        status = lp3952_configure(priv);
        if (status) {
                dev_err(&client->dev, "Probe failed. Device not found (%d)\n",
                        status);
                return status;
        }

        status = lp3952_register_led_classdev(priv);
        if (status) {
                dev_err(&client->dev, "Unable to register led_classdev: %d\n",
                        status);
                return status;
        }

        return 0;
}

static const struct i2c_device_id lp3952_id[] = {
        { .name = LP3952_NAME },
        { }
};
MODULE_DEVICE_TABLE(i2c, lp3952_id);

static struct i2c_driver lp3952_i2c_driver = {
        .driver = {
                        .name = LP3952_NAME,
        },
        .probe = lp3952_probe,
        .id_table = lp3952_id,
};

module_i2c_driver(lp3952_i2c_driver);

MODULE_AUTHOR("Tony Makkiel <tony.makkiel@daqri.com>");
MODULE_DESCRIPTION("lp3952 I2C LED controller driver");
MODULE_LICENSE("GPL v2");