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Date:   Thu, 22 Jun 2023 19:10:50 +0100
From:   Lee Jones <lee@kernel.org>
To:     =?iso-8859-1?Q?Andr=E9?= Apitzsch <git@apitzsch.eu>
Cc:     Pavel Machek <pavel@ucw.cz>, Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Conor Dooley <conor+dt@kernel.org>, linux-leds@vger.kernel.org,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
        ~postmarketos/upstreaming@lists.sr.ht
Subject: Re: [PATCH 2/2] leds: add ktd202x driver
Message-ID: <20230622181050.GY10378@google.com>
References: <20230618-ktd202x-v1-0-fc182fefadd7@apitzsch.eu>
 <20230618-ktd202x-v1-2-fc182fefadd7@apitzsch.eu>
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In-Reply-To: <20230618-ktd202x-v1-2-fc182fefadd7@apitzsch.eu>
Precedence: bulk

On Sun, 18 Jun 2023, André Apitzsch wrote:

> This commit adds support for Kinetic KTD2026/7 RGB/White LED driver.
> 
> Signed-off-by: André Apitzsch <git@apitzsch.eu>
> ---
>  drivers/leds/rgb/Kconfig        |  12 +
>  drivers/leds/rgb/Makefile       |   1 +
>  drivers/leds/rgb/leds-ktd202x.c | 610 ++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 623 insertions(+)
> 
> diff --git a/drivers/leds/rgb/Kconfig b/drivers/leds/rgb/Kconfig
> index 360c8679c6e2..fa422e7a3f74 100644
> --- a/drivers/leds/rgb/Kconfig
> +++ b/drivers/leds/rgb/Kconfig
> @@ -2,6 +2,18 @@
>  
>  if LEDS_CLASS_MULTICOLOR
>  
> +config LEDS_KTD202X
> +	tristate "LED support for KTD202x Chips"
> +	depends on I2C
> +	depends on OF
> +	select REGMAP_I2C
> +	help
> +	  This option enables support for LEDs connected to the KTD202x
> +	  chip.

More info please.

Who makes it?  Where can it be found?  What is it?  What does it do?

> +	  To compile this driver as a module, choose M here: the module
> +	  will be called leds-ktd202x.
> +
>  config LEDS_PWM_MULTICOLOR
>  	tristate "PWM driven multi-color LED Support"
>  	depends on PWM
> diff --git a/drivers/leds/rgb/Makefile b/drivers/leds/rgb/Makefile
> index 8c01daf63f61..5b4f22e077c0 100644
> --- a/drivers/leds/rgb/Makefile
> +++ b/drivers/leds/rgb/Makefile
> @@ -1,5 +1,6 @@
>  # SPDX-License-Identifier: GPL-2.0
>  
> +obj-$(CONFIG_LEDS_KTD202X)		+= leds-ktd202x.o
>  obj-$(CONFIG_LEDS_PWM_MULTICOLOR)	+= leds-pwm-multicolor.o
>  obj-$(CONFIG_LEDS_QCOM_LPG)		+= leds-qcom-lpg.o
>  obj-$(CONFIG_LEDS_MT6370_RGB)		+= leds-mt6370-rgb.o
> diff --git a/drivers/leds/rgb/leds-ktd202x.c b/drivers/leds/rgb/leds-ktd202x.c
> new file mode 100644
> index 000000000000..4f0cc558c797
> --- /dev/null
> +++ b/drivers/leds/rgb/leds-ktd202x.c
> @@ -0,0 +1,610 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +// Driver for Kinetic KTD2026/7 RGB/White LED driver

No C++ comments beyond the SPDX please.

Copyright?  Author?  Date?  Description.

> +#include <linux/i2c.h>
> +#include <linux/led-class-multicolor.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <linux/of.h>
> +#include <linux/of_device.h>
> +#include <linux/regmap.h>
> +#include <linux/regulator/consumer.h>
> +
> +#define KTD202X_MAX_LEDS 4
> +
> +#define KTD202X_REG_RESET_CONTROL	0x00
> +#define KTD202X_REG_FLASH_PERIOD	0x01
> +#define KTD202X_REG_PWM1_TIMER		0x02
> +#define KTD202X_REG_PWM2_TIMER		0x03
> +#define KTD202X_REG_CHANNEL_CTRL	0x04
> +#define KTD202X_REG_TRISE_FALL		0x05
> +#define KTD202X_REG_LED_IOUT(x)		(0x06 + (x))
> +
> +#define KTD202X_RSTR_RESET 0x07
> +
> +#define KTD202X_ENABLE_CTRL_WAKE 0x00 /* SCL & SDA High */
> +#define KTD202X_ENABLE_CTRL_SLEEP 0x08 /* SCL=High & SDA Toggling */

The formatting between the 2 comments above is making my OCD twitch.

> +#define KTD202X_CHANNEL_CTRL_MASK(x) (BIT(2 * (x)) | BIT(2 * (x) + 1))
> +#define KTD202X_CHANNEL_CTRL_OFF 0
> +#define KTD202X_CHANNEL_CTRL_ON(x) BIT(2 * (x))
> +#define KTD202X_CHANNEL_CTRL_PWM1(x) BIT(2 * (x) + 1)
> +#define KTD202X_CHANNEL_CTRL_PWM2(x) (BIT(2 * (x)) | BIT(2 * (x) + 1))
> +
> +#define KTD202X_TIME_MIN 256 /* ms */

Put MS in the name, then omit the comment.

> +#define KTD202X_TIME_STEP 128 /* ms */
> +#define KTD202X_ON_MAX 256
> +
> +static const struct reg_default ktd202x_reg_defaults[] = {
> +	{ KTD202X_REG_RESET_CONTROL, 0x00 },
> +	{ KTD202X_REG_FLASH_PERIOD, 0x00 },
> +	{ KTD202X_REG_PWM1_TIMER, 0x01 },
> +	{ KTD202X_REG_PWM2_TIMER, 0x01 },
> +	{ KTD202X_REG_CHANNEL_CTRL, 0x00 },
> +	{ KTD202X_REG_TRISE_FALL, 0x00 },
> +	{ KTD202X_REG_LED_IOUT(0), 0x4f },
> +	{ KTD202X_REG_LED_IOUT(1), 0x4f },
> +	{ KTD202X_REG_LED_IOUT(2), 0x4f },
> +	{ KTD202X_REG_LED_IOUT(3), 0x4f },

What do these magic numbers mean?

Better to define them I think.

> +};
> +
> +struct ktd202x;

No forward declarations, please reorder your structs.

> +struct ktd202x_led {
> +	struct ktd202x *chip;
> +	union {
> +		struct led_classdev cdev;
> +		struct led_classdev_mc mcdev;
> +	};
> +	u32 index;
> +};
> +
> +struct ktd202x {
> +	struct mutex mutex; /* held when writing to registers */

This comment is superfluous.

> +	struct regulator *vin_regulator;
> +	struct device *dev;
> +	struct regmap *regmap;
> +	bool enabled;
> +	int num_leds;
> +	struct ktd202x_led leds[KTD202X_MAX_LEDS];

Please restructure so you do not have interwoven deps.

This should not be a thing:

ktd202x->ktd202x_led->ktd202x->ktd202x_led

> +};
> +
> +struct ktd202x_info {
> +	unsigned int num_leds;
> +};

Do you need a whole struct for one value?

> +static const struct ktd202x_info ktd2026 = {
> +	.num_leds = 3,
> +};
> +
> +static const struct ktd202x_info ktd2027 = {
> +	.num_leds = 4,
> +};
> +
> +static int ktd202x_chip_init(struct ktd202x *chip)
> +{
> +	int ret;
> +
> +	ret = regmap_write(chip->regmap, KTD202X_REG_RESET_CONTROL,
> +			   KTD202X_ENABLE_CTRL_WAKE);

Why does this have to be its own function?

Can't we just put this call inside _chip_enable()?

> +
> +	if (ret) {
> +		dev_err(chip->dev, "Failed to enable the chip: %d\n", ret);
> +		return ret;
> +	}
> +
> +	return ret;
> +}
> +
> +static void ktd202x_chip_disable(struct ktd202x *chip)
> +{
> +	int ret;
> +
> +	if (!chip->enabled)
> +		return;
> +
> +	regmap_write(chip->regmap, KTD202X_REG_RESET_CONTROL,
> +		     KTD202X_ENABLE_CTRL_SLEEP);
> +
> +	ret = regulator_disable(chip->vin_regulator);
> +	if (ret) {
> +		dev_err(chip->dev, "Failed to disable regulator: %d\n", ret);

I would avoid printing out errors that have no affect or meaning.

Since you are not returning an error, perhaps just make this a warn.

Better yet, return the error?

> +		return;
> +	}
> +
> +	chip->enabled = false;
> +}
> +
> +static int ktd202x_chip_enable(struct ktd202x *chip)
> +{
> +	int ret;
> +
> +	if (chip->enabled)
> +		return 0;
> +
> +	ret = regulator_enable(chip->vin_regulator);
> +	if (ret) {
> +		dev_err(chip->dev, "Failed to enable regulator: %d\n", ret);
> +		return ret;
> +	}
> +	chip->enabled = true;

Does this require locks?

> +	ret = ktd202x_chip_init(chip);
> +	if (ret)
> +		ktd202x_chip_disable(chip);
> +
> +	return ret;
> +}
> +
> +static bool ktd202x_chip_in_use(struct ktd202x *chip)
> +{
> +	int i;
> +
> +	if (chip->num_leds == 1) {

Why are we treating one LED differently to >=2?

> +		if (chip->leds[0].mcdev.led_cdev.brightness)
> +			return true;
> +	} else {
> +		for (i = 0; i < chip->num_leds; i++)
> +			if (chip->leds[i].cdev.brightness)
> +				return true;
> +	}
> +	return false;
> +}
> +
> +static void ktd202x_brightness_set(struct ktd202x_led *led, struct led_classdev *cdev,
> +				   struct mc_subled *subleds, unsigned int num_colors)

Why have channels suddenly been converted to colours?

> +{
> +	enum led_brightness brightness;
> +	int idx;
> +	int ret;
> +	int i;
> +
> +	if (ktd202x_chip_in_use(led->chip)) {
> +		ret = ktd202x_chip_enable(led->chip);

Why are we ignoring return values?

> +		if (ret)
> +			return;
> +	}
> +
> +	for (i = 0; i < num_colors; i++) {
> +		idx = subleds[i].channel;
> +		brightness = subleds[i].brightness;
> +
> +		ret = regmap_write(led->chip->regmap, KTD202X_REG_LED_IOUT(idx),
> +				   brightness ? brightness-1 : 0);
> +		if (ret)
> +			return;
> +
> +		if (brightness) {
> +			ret = regmap_update_bits(led->chip->regmap,
> +						 KTD202X_REG_CHANNEL_CTRL,
> +						 KTD202X_CHANNEL_CTRL_MASK(idx),
> +						 KTD202X_CHANNEL_CTRL_ON(idx));
> +		} else {
> +			ret = regmap_update_bits(led->chip->regmap,
> +						 KTD202X_REG_CHANNEL_CTRL,
> +						 KTD202X_CHANNEL_CTRL_MASK(idx),
> +						 KTD202X_CHANNEL_CTRL_OFF);
> +		}
> +		if (ret)
> +			return;
> +	}
> +
> +	if (!ktd202x_chip_in_use(led->chip))
> +		ktd202x_chip_disable(led->chip);
> +}
> +
> +static int ktd202x_brightness_single_set(struct led_classdev *cdev,
> +					 enum led_brightness value)
> +{
> +	struct ktd202x_led *led = container_of(cdev, struct ktd202x_led, cdev);
> +	struct mc_subled info;
> +	int num_channels = 1;

Why do you need a variable for this?

> +	mutex_lock(&led->chip->mutex);
> +
> +	info.brightness = value;
> +	info.channel = led->index;
> +	ktd202x_brightness_set(led, cdev, &info, num_channels);
> +
> +	mutex_unlock(&led->chip->mutex);
> +
> +	return 0;

This could be a lie, right?  Why not aggregate the received error values?

> +}
> +
> +static int ktd202x_brightness_mc_set(struct led_classdev *cdev,
> +				     enum led_brightness value)
> +{
> +	struct led_classdev_mc *mc = lcdev_to_mccdev(cdev);
> +	struct ktd202x_led *led = container_of(mc, struct ktd202x_led, mcdev);
> +
> +	mutex_lock(&led->chip->mutex);
> +
> +	led_mc_calc_color_components(mc, value);
> +	ktd202x_brightness_set(led, cdev, mc->subled_info, mc->num_colors);
> +
> +	mutex_unlock(&led->chip->mutex);
> +
> +	return 0;
> +}
> +
> +static int ktd202x_blink_set(struct ktd202x_led *led, struct led_classdev *cdev,
> +			     unsigned long *delay_on, unsigned long *delay_off,
> +			     u8 ctrl_mask, u8 ctrl_on, u8 ctrl_pwm1)
> +{
> +	unsigned long delay_total; /* ms */

Change the variable name.

> +	int ret, num_steps, on;
> +
> +	/* Never off - brightness is already set, disable blinking */
> +	if (!*delay_off) {
> +		ret = regmap_update_bits(led->chip->regmap,
> +					 KTD202X_REG_CHANNEL_CTRL,
> +					 ctrl_mask,
> +					 ctrl_on);
> +		return ret;
> +	}
> +
> +	/* Convert into values the HW will understand. */
> +	num_steps = (*delay_on + *delay_off - KTD202X_TIME_MIN) /
> +		    KTD202X_TIME_STEP + 1;
> +	num_steps = min(126, num_steps);

Please define this magic number.

> +	on = (*delay_on * KTD202X_ON_MAX) / (*delay_on + *delay_off);
> +
> +	delay_total = num_steps * KTD202X_TIME_STEP + KTD202X_TIME_MIN;
> +	*delay_on = (delay_total * on) / KTD202X_ON_MAX;
> +	*delay_off = delay_total - *delay_on;

Care to add a few comments to save the reader a few moments?

> +	/* Set timings */
> +	ret = regmap_write(led->chip->regmap, KTD202X_REG_FLASH_PERIOD,
> +			   num_steps);
> +	if (ret)
> +		return ret;

'\n' here.

> +	ret = regmap_write(led->chip->regmap, KTD202X_REG_PWM1_TIMER, on);
> +	if (ret)
> +		return ret;
> +
> +	ret = regmap_update_bits(led->chip->regmap, KTD202X_REG_CHANNEL_CTRL,
> +				 ctrl_mask,
> +				 ctrl_pwm1);
> +	return ret;
> +}
> +
> +static int ktd202x_blink_single_set(struct led_classdev *cdev,
> +				    unsigned long *delay_on,
> +				    unsigned long *delay_off)
> +{
> +	struct ktd202x_led *led = container_of(cdev, struct ktd202x_led, cdev);
> +	struct led_classdev *lcdev;

What's the difference between lcdev and cdev?

If nothing, please keep the nomenclature consistent throughout.

> +	int index, ret;
> +	u8 ctrl_mask;
> +	u8 ctrl_on;
> +	u8 ctrl_pwm1;
> +
> +	lcdev = &led->cdev;

Why can't this be part of the declaration above?

> +	/* If no blink specified, default to 1 Hz. */
> +	if (!*delay_off && !*delay_on) {
> +		*delay_off = 500;
> +		*delay_on = 500;
> +	}
> +
> +	if (!lcdev->brightness) {
> +		lcdev->brightness = LED_FULL;

LED_FULL is supposed to be deprecated:

https://elixir.bootlin.com/linux/latest/source/include/linux/leds.h#L32

> +		ret = ktd202x_brightness_single_set(lcdev, lcdev->brightness);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	/* Never on - just set to off */
> +	if (!*delay_on) {
> +		lcdev->brightness = LED_OFF;

Instead of setting this before the call here and above, can you do it
centrally inside the call?

> +		return ktd202x_brightness_single_set(lcdev, LED_OFF);
> +	}
> +
> +	index = led->index;
> +	ctrl_mask = KTD202X_CHANNEL_CTRL_MASK(index);
> +	ctrl_on = KTD202X_CHANNEL_CTRL_ON(index);
> +	ctrl_pwm1 = KTD202X_CHANNEL_CTRL_PWM1(index);
> +
> +	mutex_lock(&led->chip->mutex);

Maybe lock inside the call, save some lines here and below?

> +	ret = ktd202x_blink_set(led, lcdev, delay_on, delay_off, ctrl_mask,
> +				ctrl_on, ctrl_pwm1);
> +
> +	mutex_unlock(&led->chip->mutex);
> +
> +	return ret;
> +}
> +
> +static int ktd202x_blink_mc_set(struct led_classdev *cdev,
> +				unsigned long *delay_on,
> +				unsigned long *delay_off)
> +{
> +	struct led_classdev_mc *mc = lcdev_to_mccdev(cdev);
> +	struct ktd202x_led *led = container_of(mc, struct ktd202x_led, mcdev);
> +	struct led_classdev *lcdev;
> +	u8 ctrl_mask = 0;
> +	u8 ctrl_on = 0;
> +	u8 ctrl_pwm1 = 0;
> +	int ret, i;
> +
> +	lcdev = &led->mcdev.led_cdev;
> +
> +	/* If no blink specified, default to 1 Hz. */
> +	if (!*delay_off && !*delay_on) {
> +		*delay_off = 500;
> +		*delay_on = 500;
> +	}

Can this be moved down below the 2 early returns below?

> +	if (!lcdev->brightness) {
> +		lcdev->brightness = LED_FULL;
> +		ret = ktd202x_brightness_mc_set(lcdev, lcdev->brightness);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	/* Never on - just set to off */
> +	if (!*delay_on) {
> +		lcdev->brightness = LED_OFF;
> +		return ktd202x_brightness_mc_set(lcdev, LED_OFF);
> +	}

I see a lot of hoop jumping and code repetition between single and
multi-color.  Is there no way to treat the multi-color case as multiple
single colours?

> +	for (i = 0; i < mc->num_colors; i++) {
> +		int index = mc->subled_info[i].channel;
> +
> +		ctrl_mask |= KTD202X_CHANNEL_CTRL_MASK(index);
> +		ctrl_on |= KTD202X_CHANNEL_CTRL_ON(index);
> +		ctrl_pwm1 |= KTD202X_CHANNEL_CTRL_PWM1(index);
> +	}
> +
> +	mutex_lock(&led->chip->mutex);
> +
> +	ret = ktd202x_blink_set(led, lcdev, delay_on, delay_off, ctrl_mask,
> +				ctrl_on, ctrl_pwm1);
> +
> +	mutex_unlock(&led->chip->mutex);
> +
> +	return ret;
> +}
> +
> +static int ktd202x_add_led(struct ktd202x *chip, struct device_node *np,
> +			   unsigned int index)
> +{
> +	struct led_init_data init_data = {};
> +	struct led_classdev *cdev;
> +	struct device_node *child;
> +	struct mc_subled *info;
> +	struct ktd202x_led *led = &chip->leds[index];
> +	int num_channels;
> +	u32 color = 0;
> +	u32 reg;
> +	int ret;
> +	int i;
> +
> +	ret = of_property_read_u32(np, "color", &color);
> +	if (ret < 0 && ret != -EINVAL) {

This is unusual.  Why are we allowing -EINVAL?

Does this make it optional?

If that's the case, perhaps a comment?

> +		dev_err(chip->dev, "failed to parse \"color\" of %pOF\n", np);

That's pretty ugly.  Can you use single quotes instead?

> +		return ret;
> +	}
> +
> +	if (color == LED_COLOR_ID_RGB) {
> +		num_channels = of_get_available_child_count(np);
> +		if (!num_channels || num_channels > chip->num_leds)
> +			return -EINVAL;
> +	} else {
> +		num_channels = 1;
> +	}
> +
> +	led->chip = chip;
> +
> +	if (color == LED_COLOR_ID_RGB) {
> +		info = devm_kcalloc(chip->dev, num_channels, sizeof(*info),
> +				    GFP_KERNEL);
> +		if (!info)
> +			return -ENOMEM;
> +
> +		i = 0;
> +		for_each_available_child_of_node(np, child) {
> +			u32 color = 0;

Not sure I've seen anyone overload a variable in the kernel before.

LED_COLOR_ID_WHITE

Is that correct?  No colour means that it's white?

> +			ret = of_property_read_u32(child, "reg", &reg);
> +			if (ret != 0 || reg >= chip->num_leds) {
> +				dev_err(chip->dev, "invalid \"reg\" of %pOFn\n",
> +					np);
> +				return -EINVAL;
> +			}
> +
> +			ret = of_property_read_u32(child, "color", &color);
> +			if (ret < 0 && ret != -EINVAL) {
> +				dev_err(chip->dev,
> +					"failed to parse \"color\" of %pOF\n",
> +					np);
> +				return ret;
> +			}
> +
> +			info[i].color_index = color;
> +			info[i].channel = reg;
> +			info[i].intensity = 0;
> +			i++;
> +		}
> +
> +		led->mcdev.subled_info = info;
> +		led->mcdev.num_colors = num_channels;
> +
> +		cdev = &led->mcdev.led_cdev;
> +		cdev->brightness_set_blocking = ktd202x_brightness_mc_set;
> +		cdev->blink_set = ktd202x_blink_mc_set;
> +	} else {
> +		ret = of_property_read_u32(np, "reg", &reg);
> +		if (ret != 0 || reg >= chip->num_leds) {
> +			dev_err(chip->dev, "invalid \"reg\" of %pOFn\n", np);
> +			return -EINVAL;
> +		}
> +		led->index = reg;
> +
> +		cdev = &led->cdev;
> +		cdev->brightness_set_blocking = ktd202x_brightness_single_set;
> +		cdev->blink_set = ktd202x_blink_single_set;
> +	}
> +
> +	cdev->max_brightness = 192;

Define please.

> +	init_data.fwnode = of_fwnode_handle(np);
> +
> +	if (color == LED_COLOR_ID_RGB)
> +		ret = devm_led_classdev_multicolor_register_ext(chip->dev,
> +								&led->mcdev,
> +								&init_data);
> +	else
> +		ret = devm_led_classdev_register_ext(chip->dev, &led->cdev,
> +						     &init_data);
> +	if (ret) {
> +		dev_err(chip->dev, "unable to register %s\n", cdev->name);
> +		of_node_put(np);
> +	}
> +
> +	return ret;
> +}
> +
> +static int ktd202x_probe_dt(struct ktd202x *chip)
> +{
> +	struct device_node *np = dev_of_node(chip->dev), *child;
> +	const struct ktd202x_info *ktd202x;
> +	unsigned int i;
> +	int count, ret;
> +
> +	ktd202x = of_device_get_match_data(chip->dev);
> +	if (!ktd202x)
> +		return -ENODEV;
> +
> +	chip->num_leds = ktd202x->num_leds;
> +
> +	count = of_get_available_child_count(np);
> +	if (!count || count > ktd202x->num_leds)
> +		return -EINVAL;
> +
> +	regmap_write(chip->regmap, KTD202X_REG_RESET_CONTROL,
> +		     KTD202X_RSTR_RESET);

'\n'

> +	/* allow the device to execute the complete reset */

"Allow"

> +	usleep_range(200, 300);
> +
> +	i = 0;
> +	for_each_available_child_of_node(np, child) {
> +		ret = ktd202x_add_led(chip, child, i);
> +		if (ret)
> +			return ret;
> +		i++;
> +	}
> +
> +	return 0;
> +}
> +
> +static const struct regmap_config ktd202x_regmap_config = {
> +	.reg_bits = 8,
> +	.val_bits = 8,
> +	.max_register = 0x09,
> +	.cache_type = REGCACHE_FLAT,
> +	.reg_defaults = ktd202x_reg_defaults,
> +	.num_reg_defaults = ARRAY_SIZE(ktd202x_reg_defaults),
> +};
> +
> +static int ktd202x_probe(struct i2c_client *client)
> +{
> +	struct ktd202x *chip;
> +	int ret;
> +
> +	chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
> +	if (!chip)
> +		return -ENOMEM;
> +
> +	mutex_init(&chip->mutex);
> +	mutex_lock(&chip->mutex);

Locking during the whole of probe is unusual.

Are you sure this is required?

> +	chip->dev = &client->dev;
> +	i2c_set_clientdata(client, chip);
> +
> +	chip->regmap = devm_regmap_init_i2c(client, &ktd202x_regmap_config);
> +	if (IS_ERR(chip->regmap)) {
> +		ret = dev_err_probe(&client->dev, PTR_ERR(chip->regmap),
> +				    "Failed to allocate register map.\n");
> +		goto error;
> +	}
> +
> +	chip->vin_regulator = devm_regulator_get(&client->dev, "vin");
> +	ret = PTR_ERR_OR_ZERO(chip->vin_regulator);
> +	if (ret) {
> +		dev_err_probe(&client->dev, ret,
> +			      "Failed to request regulator.\n");
> +		goto error;
> +	}
> +
> +	ret = regulator_enable(chip->vin_regulator);
> +	if (ret) {
> +		dev_err_probe(&client->dev, ret,
> +			      "Failed to enable regulator.\n");
> +		goto error;
> +	}
> +
> +	ret = ktd202x_probe_dt(chip);
> +	if (ret < 0)
> +		goto error_reg;
> +
> +	ret = regulator_disable(chip->vin_regulator);
> +	if (ret) {
> +		dev_err_probe(&client->dev, ret,
> +			      "Failed to disable regulator.\n");
> +		goto error;
> +	}
> +
> +	mutex_unlock(&chip->mutex);
> +
> +	return 0;
> +
> +error_reg:
> +	regulator_disable(chip->vin_regulator);
> +
> +error:
> +	mutex_destroy(&chip->mutex);

No need to unlock first?

> +	return ret;
> +}
> +
> +static void ktd202x_remove(struct i2c_client *client)
> +{
> +	struct ktd202x *chip = i2c_get_clientdata(client);
> +
> +	ktd202x_chip_disable(chip);
> +
> +	mutex_destroy(&chip->mutex);
> +}
> +
> +static void ktd202x_shutdown(struct i2c_client *client)
> +{
> +	struct ktd202x *chip = i2c_get_clientdata(client);
> +
> +	/* Reset registers to make sure all off before shutdown */
> +	regmap_write(chip->regmap, KTD202X_REG_RESET_CONTROL,
> +		     KTD202X_RSTR_RESET);
> +}
> +
> +static const struct of_device_id ktd202x_match_table[] = {
> +	{ .compatible = "kinetic,ktd2026", .data = &ktd2026 },

.data = KTD2026_NUM_LEDS;

> +	{ .compatible = "kinetic,ktd2027", .data = &ktd2027 },
> +	{ /* sentinel */ },

Please remove this comment.  We know how NULL entries work.

> +};
> +
> +MODULE_DEVICE_TABLE(of, ktd202x_match_table);
> +
> +static struct i2c_driver ktd202x_driver = {
> +	.driver = {
> +		.name = "leds-ktd202x",
> +		.of_match_table = of_match_ptr(ktd202x_match_table),

Last I heard we were removing these of_match_ptr()s?

Might be old info though.  Someone else should confirm.

> +	},
> +	.probe_new = ktd202x_probe,
> +	.remove = ktd202x_remove,
> +	.shutdown = ktd202x_shutdown,
> +};
> +

Remove this line.

> +module_i2c_driver(ktd202x_driver);
> +
> +MODULE_AUTHOR("André Apitzsch <git@apitzsch.eu>");
> +MODULE_DESCRIPTION("Kinetic KTD2026/7 LED driver");
> +MODULE_LICENSE("GPL");
> 
> -- 
> 2.41.0
> 

-- 
Lee Jones [李琼斯]