[PATCH v6 2/2] leds: bd2606mvv: Driver for the Rohm 6 Channel i2c LED driver

Andreas Kemnade
2023-04-19T11:19:11Z

The device provides 6 channels which can be individually
turned off and on but groups of two channels share a common brightness
register.

Limitation: The GPIO to enable the device is not used yet.

Signed-off-by: Andreas Kemnade <andreas@kemnade.info>
Reviewed-by: Matti Vaittinen <mazziesaccount@gmail.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
---
drivers/leds/Kconfig | 14 +++
drivers/leds/Makefile | 1 +
drivers/leds/leds-bd2606mvv.c | 160 ++++++++++++++++++++++++++++++++++
3 files changed, 175 insertions(+)
create mode 100644 drivers/leds/leds-bd2606mvv.c

diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index 9dbce09eabacf..09afc56f54f16 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -551,6 +551,20 @@ config LEDS_REGULATOR
help
This option enables support for regulator driven LEDs.

+config LEDS_BD2606MVV
+ tristate "LED driver for BD2606MVV"
+ depends on LEDS_CLASS
+ depends on I2C
+ select REGMAP_I2C
+ help
+ This option enables support for BD2606MVV LED driver chips
+ accessed via the I2C bus. It supports setting brightness, with
+ the limitiation that there are groups of two channels sharing
+ a brightness setting, but not the on/off setting.
+
+ To compile this driver as a module, choose M here: the module will
+ be called leds-bd2606mvv.
+
config LEDS_BD2802
tristate "LED driver for BD2802 RGB LED"
depends on LEDS_CLASS
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index d30395d11fd84..c07d1512c745a 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -17,6 +17,7 @@ obj-$(CONFIG_LEDS_ARIEL) += leds-ariel.o
obj-$(CONFIG_LEDS_AW2013) += leds-aw2013.o
obj-$(CONFIG_LEDS_BCM6328) += leds-bcm6328.o
obj-$(CONFIG_LEDS_BCM6358) += leds-bcm6358.o
+obj-$(CONFIG_LEDS_BD2606MVV) += leds-bd2606mvv.o
obj-$(CONFIG_LEDS_BD2802) += leds-bd2802.o
obj-$(CONFIG_LEDS_BLINKM) += leds-blinkm.o
obj-$(CONFIG_LEDS_CLEVO_MAIL) += leds-clevo-mail.o
diff --git a/drivers/leds/leds-bd2606mvv.c b/drivers/leds/leds-bd2606mvv.c
new file mode 100644
index 0000000000000..76f9d4d70f9a6
--- /dev/null
+++ b/drivers/leds/leds-bd2606mvv.c
@@ -0,0 +1,160 @@
+// 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 fwnode_handle *np, *child;
+ 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;
+
+ np = dev_fwnode(dev);
+ if (!np)
+ 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);
+
+ fwnode_for_each_available_child_node(np, child) {
+ struct bd2606mvv_led *led;
+
+ err = fwnode_property_read_u32(child, "reg", &reg);
+ if (err) {
+ fwnode_handle_put(child);
+ return err;
+ }
+ if (reg < 0 || reg >= BD2606_MAX_LEDS || led_fwnodes[reg]) {
+ fwnode_handle_put(child);
+ return -EINVAL;
+ }
+ led = &priv->leds[reg];
+ led_fwnodes[reg] = 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) {
+ fwnode_handle_put(child);
+ 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_new = bd2606mvv_probe,
+};
+
+module_i2c_driver(bd2606mvv_driver);
+
+MODULE_AUTHOR("Andreas Kemnade <andreas@kemnade.info>");
+MODULE_DESCRIPTION("BD2606 LED driver");
+MODULE_LICENSE("GPL");
--
2.39.2