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Date: Thu, 6 Apr 2023 11:57:15 +0300
From: Matti Vaittinen <mazziesaccount@...il.com>
To: Andreas Kemnade <andreas@...nade.info>, pavel@....cz,
lee@...nel.org, robh+dt@...nel.org,
krzysztof.kozlowski+dt@...aro.org, linux-leds@...r.kernel.org,
devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
hns@...delico.com
Subject: Re: [PATCH 2/2] leds: bd2606mvv: Driver for the Rohm 6 Channel i2c
LED driver
Hi Andreas,
Overall a nice and clean driver with a good explanation of shared
brightness. Just some minor things.
On 4/6/23 09:08, Andreas Kemnade wrote:
> The device provides 6 channels which can be individually
> turned off and on but groups of two channels share a common brightness
> register.
>
> Signed-off-by: Andreas Kemnade <andreas@...nade.info>
> ---
> drivers/leds/Kconfig | 11 +++
> drivers/leds/Makefile | 1 +
> drivers/leds/leds-bd2606mvv.c | 145 ++++++++++++++++++++++++++++++++++
> 3 files changed, 157 insertions(+)
> create mode 100644 drivers/leds/leds-bd2606mvv.c
>
> diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
> index 9dbce09eabacf..cc4eadbb2542e 100644
> --- a/drivers/leds/Kconfig
> +++ b/drivers/leds/Kconfig
> @@ -551,6 +551,17 @@ 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.
> +
> 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..47ddd016bae3f
> --- /dev/null
> +++ b/drivers/leds/leds-bd2606mvv.c
> @@ -0,0 +1,145 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (C) 2023 Andreas Kemnade
Could add a link to data-sheet here.
> + */
> +
> +#include <linux/i2c.h>
> +#include <linux/leds.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_device.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 {
> + bool active;
I didn't spot where this 'active' was used?
> + 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);
> + }
could drop the brackets.
> +
> + /* shared brightness register */
> + err = regmap_write(priv->regmap, led->led_no / 2,
> + 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_node *np, *child;
Is it possible to only use the fwnode? I think the more generic fwnode_*
is preferred over of_*.
> + struct device *dev = &client->dev;
> + struct bd2606mvv_priv *priv;
> + int err, count, reg;
> +
> + np = dev_of_node(dev);
> + if (!np)
> + return -ENODEV;
> +
> + count = of_get_available_child_count(np);
> + if (!count || count > BD2606_MAX_LEDS)
> + return -EINVAL;
> +
> + 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);
> +
The IC seems to have an enable pin. I think you might add the
enable-gpio in dt-bindings and try to (optionally) get and enable it here.
> + for_each_available_child_of_node(np, child) {
> + struct bd2606mvv_led *led;
> + struct led_init_data init_data = {};
> +
> + init_data.fwnode = of_fwnode_handle(child);
> +
> + err = of_property_read_u32(child, "reg", ®);
> + if (err) {
> + of_node_put(child);
> + return err;
> + }
> + if (reg < 0 || reg >= BD2606_MAX_LEDS ||
> + priv->leds[reg].active) {
> + of_node_put(child);
> + return -EINVAL;
> + }
> + led = &priv->leds[reg];
> +
> + led->active = true;
> + led->priv = priv;
> + led->led_no = reg;
> + led->ldev.brightness_set_blocking = bd2606mvv_brightness_set;
> + led->ldev.max_brightness = BD2606_MAX_BRIGHTNESS;
> + err = devm_led_classdev_register_ext(dev, &led->ldev,
> + &init_data);
> + if (err < 0) {
> + of_node_put(child);
> + return dev_err_probe(dev, err,
> + "couldn't register LED %s\n",
> + led->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@...nade.info>");
> +MODULE_DESCRIPTION("BD2606 LED driver");
> +MODULE_LICENSE("GPL");
Yours,
-- Matti
--
Matti Vaittinen
Linux kernel developer at ROHM Semiconductors
Oulu Finland
~~ When things go utterly wrong vim users can always type :help! ~~
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