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linux/drivers/leds/leds-bd2606mvv.c

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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2023 Andreas Kemnade
*
* Datasheet:
* https://fscdn.rohm.com/en/products/databook/datasheet/ic/power/led_driver/bd2606mvv_1-e.pdf
*
* If LED brightness cannot be controlled independently due to shared
* brightness registers, max_brightness is set to 1 and only on/off
* is possible for the affected LED pair.
*/
#include <linux/i2c.h>
#include <linux/leds.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/property.h>
#include <linux/regmap.h>
#include <linux/slab.h>
#define BD2606_MAX_LEDS 6
#define BD2606_MAX_BRIGHTNESS 63
#define BD2606_REG_PWRCNT 3
#define ldev_to_led(c) container_of(c, struct bd2606mvv_led, ldev)
struct bd2606mvv_led {
unsigned int led_no;
struct led_classdev ldev;
struct bd2606mvv_priv *priv;
};
struct bd2606mvv_priv {
struct bd2606mvv_led leds[BD2606_MAX_LEDS];
struct regmap *regmap;
};
static int
bd2606mvv_brightness_set(struct led_classdev *led_cdev,
enum led_brightness brightness)
{
struct bd2606mvv_led *led = ldev_to_led(led_cdev);
struct bd2606mvv_priv *priv = led->priv;
int err;
if (brightness == 0)
return regmap_update_bits(priv->regmap,
BD2606_REG_PWRCNT,
1 << led->led_no,
0);
/* shared brightness register */
err = regmap_write(priv->regmap, led->led_no / 2,
led_cdev->max_brightness == 1 ?
BD2606_MAX_BRIGHTNESS : brightness);
if (err)
return err;
return regmap_update_bits(priv->regmap,
BD2606_REG_PWRCNT,
1 << led->led_no,
1 << led->led_no);
}
static const struct regmap_config bd2606mvv_regmap = {
.reg_bits = 8,
.val_bits = 8,
.max_register = 0x3,
};
static int bd2606mvv_probe(struct i2c_client *client)
{
struct device *dev = &client->dev;
struct bd2606mvv_priv *priv;
struct fwnode_handle *led_fwnodes[BD2606_MAX_LEDS] = { 0 };
int active_pairs[BD2606_MAX_LEDS / 2] = { 0 };
int err, reg;
int i, j;
if (!dev_fwnode(dev))
return -ENODEV;
priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
priv->regmap = devm_regmap_init_i2c(client, &bd2606mvv_regmap);
if (IS_ERR(priv->regmap)) {
err = PTR_ERR(priv->regmap);
dev_err(dev, "Failed to allocate register map: %d\n", err);
return err;
}
i2c_set_clientdata(client, priv);
device_for_each_child_node_scoped(dev, child) {
struct bd2606mvv_led *led;
err = fwnode_property_read_u32(child, "reg", &reg);
if (err)
return err;
if (reg < 0 || reg >= BD2606_MAX_LEDS || led_fwnodes[reg])
return -EINVAL;
led = &priv->leds[reg];
led_fwnodes[reg] = fwnode_handle_get(child);
active_pairs[reg / 2]++;
led->priv = priv;
led->led_no = reg;
led->ldev.brightness_set_blocking = bd2606mvv_brightness_set;
led->ldev.max_brightness = BD2606_MAX_BRIGHTNESS;
}
for (i = 0; i < BD2606_MAX_LEDS; i++) {
struct led_init_data init_data = {};
if (!led_fwnodes[i])
continue;
init_data.fwnode = led_fwnodes[i];
/* Check whether brightness can be independently adjusted. */
if (active_pairs[i / 2] == 2)
priv->leds[i].ldev.max_brightness = 1;
err = devm_led_classdev_register_ext(dev,
&priv->leds[i].ldev,
&init_data);
if (err < 0) {
for (j = i; j < BD2606_MAX_LEDS; j++)
fwnode_handle_put(led_fwnodes[j]);
return dev_err_probe(dev, err,
"couldn't register LED %s\n",
priv->leds[i].ldev.name);
}
}
return 0;
}
static const struct of_device_id __maybe_unused of_bd2606mvv_leds_match[] = {
{ .compatible = "rohm,bd2606mvv", },
{},
};
MODULE_DEVICE_TABLE(of, of_bd2606mvv_leds_match);
static struct i2c_driver bd2606mvv_driver = {
.driver = {
.name = "leds-bd2606mvv",
.of_match_table = of_match_ptr(of_bd2606mvv_leds_match),
},
.probe = bd2606mvv_probe,
};
module_i2c_driver(bd2606mvv_driver);
MODULE_AUTHOR("Andreas Kemnade <andreas@kemnade.info>");
MODULE_DESCRIPTION("BD2606 LED driver");
MODULE_LICENSE("GPL");