Re: [PATCH v7 2/2] leds: is32fl3207: Add controller driver
From: Lee Jones
Date: Thu Sep 10 2026 - 08:42:33 EST
On Sun, 23 Aug 2026, Ahmad Byagowi wrote:
> Add an I2C driver for the Lumissil IS32FL3207 18-channel LED controller.
>
> Expose individual and multicolor LEDs through the LED class. Use the
> default 8-bit, 62 kHz PWM mode, derive output current from RISET, and
> enforce each output current limit with the scaling registers. Serialize
> multicolor calculation, scaling, PWM, and controller-wide update
> operations.
>
> Clear retained scaling while SDB holds the outputs disabled. Release SDB
> and briefly enable normal operation to issue the required software reset,
> then keep the controller in software shutdown while registering every LED.
> Enable outputs only after all limits and initial brightness values are
> programmed.
>
> Handle an optional supply and enable GPIO. Serialize shutdown against
> pending brightness updates and honor retained shutdown state.
>
> Signed-off-by: Ahmad Byagowi <ahmadexp@xxxxxxxxx>
> ---
> MAINTAINERS | 1 +
> drivers/leds/rgb/Kconfig | 11 +
> drivers/leds/rgb/Makefile | 1 +
> drivers/leds/rgb/leds-is32fl3207.c | 736 +++++++++++++++++++++++++++++
> 4 files changed, 749 insertions(+)
> create mode 100644 drivers/leds/rgb/leds-is32fl3207.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index dbb2fc536c06..79bb970b025d 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -13822,6 +13822,7 @@ M: Ahmad Byagowi <ahmadexp@xxxxxxxxx>
> L: linux-leds@xxxxxxxxxxxxxxxx
> S: Maintained
> F: Documentation/devicetree/bindings/leds/issi,is32fl3207.yaml
> +F: drivers/leds/rgb/leds-is32fl3207.c
>
> IT87 HARDWARE MONITORING DRIVER
> M: Jean Delvare <jdelvare@xxxxxxxx>
> diff --git a/drivers/leds/rgb/Kconfig b/drivers/leds/rgb/Kconfig
> index 6e9ab5f60714..c896be1318dc 100644
> --- 'a/drivers/leds/rgb/Kconfig'
> +++ 'b/drivers/leds/rgb/Kconfig'
> @@ -14,6 +14,17 @@ config LEDS_GROUP_MULTICOLOR
> To compile this driver as a module, choose M here: the module
> will be called leds-group-multicolor.
>
> +config LEDS_IS32FL3207
> + tristate "LED support for ISSI IS32FL3207"
> + depends on I2C
> + select REGMAP_I2C
> + help
> + Say Y here to include support for the Lumissil IS32FL3207
> + 18-channel I2C LED controller.
> +
> + To compile this driver as a module, choose M here: the module will
> + be called leds-is32fl3207.
> +
> config LEDS_KTD202X
> tristate "LED support for KTD202x Chips"
> depends on I2C
> diff --git a/drivers/leds/rgb/Makefile b/drivers/leds/rgb/Makefile
> index cc0f2df66286..228923e8bb11 100644
> --- 'a/drivers/leds/rgb/Makefile'
> +++ 'b/drivers/leds/rgb/Makefile'
> @@ -1,6 +1,7 @@
> # SPDX-License-Identifier: GPL-2.0
>
> obj-$(CONFIG_LEDS_GROUP_MULTICOLOR) += leds-group-multicolor.o
> +obj-$(CONFIG_LEDS_IS32FL3207) += leds-is32fl3207.o
> obj-$(CONFIG_LEDS_KTD202X) += leds-ktd202x.o
> obj-$(CONFIG_LEDS_LP5812) += leds-lp5812.o
> obj-$(CONFIG_LEDS_LP5860_CORE) += leds-lp5860-core.o
> diff --git a/drivers/leds/rgb/leds-is32fl3207.c b/drivers/leds/rgb/leds-is32fl3207.c
> new file mode 100644
> index 000000000000..6a46f97ba50a
> --- /dev/null
> +++ 'b/drivers/leds/rgb/leds-is32fl3207.c'
> @@ -0,0 +1,736 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * ISSI IS32FL3207 LED controller driver
> + *
> + * Copyright 2026 Ahmad Byagowi
> + */
> +
> +#include <linux/bitmap.h>
> +#include <linux/delay.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/i2c.h>
> +#include <linux/led-class-multicolor.h>
> +#include <linux/math64.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <linux/property.h>
> +#include <linux/regmap.h>
> +#include <linux/regulator/consumer.h>
> +#include <linux/string.h>
> +
> +#include <dt-bindings/leds/common.h>
> +
> +#define IS32FL3207_NUM_CHANNELS 18
> +#define IS32FL3207_MAX_BRIGHTNESS 255
> +
> +#define IS32FL3207_REG_CONTROL 0x00
> +#define IS32FL3207_REG_PWM_LOW(channel) (0x01 + 2 * (channel))
> +#define IS32FL3207_REG_PWM_UPDATE 0x49
> +#define IS32FL3207_REG_SCALING(channel) (0x4a + (channel))
> +#define IS32FL3207_REG_GLOBAL_CURRENT 0x6e
> +#define IS32FL3207_REG_RESET 0x7f
> +
> +#define IS32FL3207_CONTROL_ENABLE BIT(0)
> +#define IS32FL3207_GLOBAL_CURRENT_MAX 0xff
> +
> +/* IOUT(MAX) in microamperes = 76,500,000 / RISET in ohms. */
> +#define IS32FL3207_CURRENT_NUMERATOR 76500000ULL
> +
> +struct is32fl3207;
> +
> +struct is32fl3207_led {
> + struct is32fl3207 *chip;
> + struct led_classdev *led_cdev;
Can we avoid storing the redundant 'led_cdev' pointer here? Since
'cdev' and 'mcdev.led_cdev' are unionised and share the same memory
offset, we could generalise and use '&led->cdev' whenever a pointer to
the base 'struct led_classdev' is required.
> + union {
> + struct led_classdev cdev;
> + struct led_classdev_mc mcdev;
> + };
> + unsigned int channel;
> +};
> +
> +struct is32fl3207 {
> + struct device *dev;
> + struct regmap *regmap;
> + struct gpio_desc *enable_gpio;
> + struct mutex lock; /* Serializes controller register updates. */
Not sure the comment is required here - this is what they usually do
context of device drivers.
> + unsigned long channels[BITS_TO_LONGS(IS32FL3207_NUM_CHANNELS)];
> + u32 output_max_microamp;
> + unsigned int num_leds;
> + bool shutting_down;
> + struct is32fl3207_led leds[] __counted_by(num_leds);
> +};
> +
> +static int is32fl3207_parse_led_properties(struct is32fl3207 *chip,
> + struct fwnode_handle *fwnode,
> + unsigned int *max_brightness,
> + unsigned int *brightness)
> +{
> + enum led_default_state default_state;
> + u32 value;
> + int ret;
> +
> + *max_brightness = IS32FL3207_MAX_BRIGHTNESS;
> + if (fwnode_property_present(fwnode, "max-brightness")) {
> + ret = fwnode_property_read_u32(fwnode, "max-brightness",
> + &value);
> + if (ret)
> + return dev_err_probe(chip->dev, ret,
> + "failed to read maximum brightness for %pfw\n",
> + fwnode);
> + if (!value || value > IS32FL3207_MAX_BRIGHTNESS)
> + return dev_err_probe(chip->dev, -EINVAL,
> + "invalid maximum brightness %u for %pfw\n",
> + value, fwnode);
> +
> + *max_brightness = value;
> + }
> +
> + value = *max_brightness;
> + if (fwnode_property_present(fwnode, "default-brightness")) {
> + ret = fwnode_property_read_u32(fwnode, "default-brightness",
> + &value);
> + if (ret)
> + return dev_err_probe(chip->dev, ret,
> + "failed to read default brightness for %pfw\n",
> + fwnode);
> + if (value > *max_brightness)
> + return dev_err_probe(chip->dev, -EINVAL,
> + "invalid default brightness %u for %pfw\n",
> + value, fwnode);
> + }
> +
> + default_state = led_init_default_state_get(fwnode);
> + if (default_state == LEDS_DEFSTATE_KEEP)
> + return dev_err_probe(chip->dev, -EINVAL,
> + "default state keep is not supported for %pfw\n",
> + fwnode);
> +
> + *brightness = default_state == LEDS_DEFSTATE_ON ? value : LED_OFF;
> + return 0;
> +}
> +
> +static int is32fl3207_validate_component(struct is32fl3207 *chip,
> + struct fwnode_handle *fwnode)
> +{
> + static const char * const unsupported[] = {
> + "default-brightness",
> + "default-state",
> + "max-brightness",
> + "retain-state-shutdown",
> + };
Really not sure about this. Validating everything that is unsupported
is a slippery slope. If anything, put it in the documentation and have
done.
> + unsigned int i;
> +
> + for (i = 0; i < ARRAY_SIZE(unsupported); i++)
for (int i = -; ...
> + if (fwnode_property_present(fwnode, unsupported[i]))
> + return dev_err_probe(chip->dev, -EINVAL,
> + "%s is not supported for component %pfw\n",
> + unsupported[i], fwnode);
> +
> + return 0;
> +}
> +
> +static int is32fl3207_write_channels_locked(struct is32fl3207 *chip,
> + const struct mc_subled *subleds,
> + unsigned int num_channels)
> +{
> + unsigned int i;
> + int ret;
> +
> + for (i = 0; i < num_channels; i++) {
for (int i = -; ...
> + ret = regmap_write(chip->regmap,
> + IS32FL3207_REG_PWM_LOW(subleds[i].channel),
> + subleds[i].brightness);
> + if (ret)
> + return ret;
> + }
> +
> + return regmap_write(chip->regmap, IS32FL3207_REG_PWM_UPDATE, 0);
> +}
> +
> +static int is32fl3207_brightness_set(struct led_classdev *cdev,
> + enum led_brightness brightness)
> +{
> + struct is32fl3207_led *led = container_of(cdev, struct is32fl3207_led,
> + cdev);
Use 100-chars to prevent crazy line breaks like this.
> + struct mc_subled subled = {
> + .brightness = brightness,
> + .channel = led->channel,
> + };
> +
> + guard(mutex)(&led->chip->lock);
> + if (led->chip->shutting_down)
> + return 0;
Is it even architecturally possible to set brightness on a shutdown or
disabled LED? That sounds like a bigger problem.
> +
> + return is32fl3207_write_channels_locked(led->chip, &subled, 1);
> +}
> +
> +static int is32fl3207_mc_brightness_set(struct led_classdev *cdev,
> + enum led_brightness brightness)
> +{
> + struct led_classdev_mc *mcdev = lcdev_to_mccdev(cdev);
> + struct is32fl3207_led *led = container_of(mcdev, struct is32fl3207_led,
> + mcdev);
> +
> + guard(mutex)(&led->chip->lock);
> + if (led->chip->shutting_down)
> + return 0;
> +
> + led_mc_calc_color_components(mcdev, brightness);
> +
> + return is32fl3207_write_channels_locked(led->chip, mcdev->subled_info,
> + mcdev->num_colors);
> +}
> +
> +static int is32fl3207_turn_off_locked(struct is32fl3207 *chip,
> + struct is32fl3207_led *led)
> +{
> + struct led_classdev *cdev = led->led_cdev;
> + struct mc_subled subled = {
> + .brightness = LED_OFF,
> + .channel = led->channel,
> + };
> +
> + if (cdev->flags & LED_MULTI_COLOR) {
> + struct led_classdev_mc *mcdev = lcdev_to_mccdev(cdev);
> +
> + led_mc_calc_color_components(mcdev, LED_OFF);
> + return is32fl3207_write_channels_locked(chip,
> + mcdev->subled_info,
> + mcdev->num_colors);
Is this a patch artefact? We line-up with the '('.
> + }
> +
> + return is32fl3207_write_channels_locked(chip, &subled, 1);
> +}
> +
> +static int is32fl3207_configure_channel(struct is32fl3207 *chip,
> + struct fwnode_handle *fwnode,
> + unsigned int *channel)
> +{
> + u64 scaling;
> + u32 max_microamp;
> + u32 reg;
> + int ret;
> +
> + ret = fwnode_property_read_u32(fwnode, "reg", ®);
> + if (ret)
> + return dev_err_probe(chip->dev, ret,
> + "failed to read channel for %pfw\n",
> + fwnode);
No line-break here. Same with some of lines below.
> +
> + if (reg >= IS32FL3207_NUM_CHANNELS)
> + return dev_err_probe(chip->dev, -EINVAL,
> + "channel %u is out of range\n", reg);
> +
> + if (test_bit(reg, chip->channels))
> + return dev_err_probe(chip->dev, -EINVAL,
> + "channel %u is used more than once\n",
> + reg);
> +
> + ret = fwnode_property_read_u32(fwnode, "led-max-microamp",
> + &max_microamp);
> + if (ret)
> + return dev_err_probe(chip->dev, ret,
> + "failed to read current limit for channel %u\n",
> + reg);
> +
> + if (!max_microamp || max_microamp > chip->output_max_microamp)
> + return dev_err_probe(chip->dev, -EINVAL,
> + "invalid current limit %u uA for channel %u\n",
> + max_microamp, reg);
> +
> + /* GCC is fixed at 0xff, so use each output's scaling register. */
> + scaling = div_u64((u64)max_microamp * 256 * 256,
These magic numbers need defining.
> + (u64)chip->output_max_microamp *
> + IS32FL3207_GLOBAL_CURRENT_MAX);
> + if (!scaling)
> + return dev_err_probe(chip->dev, -EINVAL,
> + "current limit %u uA is below channel %u resolution\n",
> + max_microamp, reg);
> +
> + scaling = min_t(u64, scaling, 0xff);
As above - MAX something something I presume.
> +
> + guard(mutex)(&chip->lock);
> + ret = regmap_write(chip->regmap, IS32FL3207_REG_SCALING(reg),
> + (unsigned int)scaling);
> + if (ret)
> + return ret;
> +
> + set_bit(reg, chip->channels);
> + *channel = reg;
> +
> + return 0;
> +}
> +
> +static int is32fl3207_register_single(struct is32fl3207 *chip,
> + struct fwnode_handle *fwnode,
> + struct is32fl3207_led *led)
> +{
> + struct led_init_data init_data = {
> + .devicename = dev_name(chip->dev),
> + .devname_mandatory = true,
> + .fwnode = fwnode,
> + };
> + unsigned int max_brightness;
> + unsigned int brightness;
> + u32 color;
> + int ret;
> +
> + if (!fwnode_property_present(fwnode, "function") &&
> + !fwnode_property_present(fwnode, "color"))
> + return dev_err_probe(chip->dev, -EINVAL,
> + "single LED %pfw requires function or color\n",
> + fwnode);
> +
> + ret = is32fl3207_parse_led_properties(chip, fwnode,
> + &max_brightness, &brightness);
Why not pass 'led' or 'cdev' and have this populate the brightnesses instead?
Passing pointers to ints gives me the ick!
> + if (ret)
> + return ret;
> +
> + if (fwnode_property_present(fwnode, "color")) {
> + ret = fwnode_property_read_u32(fwnode, "color", &color);
> + if (ret)
> + return dev_err_probe(chip->dev, ret,
> + "failed to read color for %pfw\n",
> + fwnode);
> + if (color >= LED_COLOR_ID_MAX || color == LED_COLOR_ID_MULTI ||
> + color == LED_COLOR_ID_RGB)
> + return dev_err_probe(chip->dev, -EINVAL,
> + "invalid single LED color %u\n",
> + color);
> + }
> +
> + ret = is32fl3207_configure_channel(chip, fwnode, &led->channel);
> + if (ret)
> + return ret;
> + led->chip = chip;
> + led->led_cdev = &led->cdev;
> + led->cdev.brightness = brightness;
> + led->cdev.max_brightness = max_brightness;
> + led->cdev.brightness_set_blocking = is32fl3207_brightness_set;
> +
> + ret = is32fl3207_brightness_set(&led->cdev, brightness);
> + if (ret)
> + return ret;
> +
> + return devm_led_classdev_register_ext(chip->dev, &led->cdev,
> + &init_data);
> +}
> +
> +static int is32fl3207_register_multicolor(struct is32fl3207 *chip,
> + struct fwnode_handle *fwnode,
> + struct is32fl3207_led *led)
> +{
> + struct led_init_data init_data = {
> + .devicename = dev_name(chip->dev),
> + .devname_mandatory = true,
> + .fwnode = fwnode,
> + };
> + struct mc_subled *subleds;
> + DECLARE_BITMAP(color_map, LED_COLOR_ID_MAX);
> + unsigned int max_brightness;
> + unsigned int brightness;
> + unsigned int count;
> + unsigned int i = 0;
> + bool has_group_reg;
> + u32 group_color;
> + u32 group_reg;
> + unsigned int first_channel = IS32FL3207_NUM_CHANNELS;
> + int ret;
> +
> + ret = is32fl3207_parse_led_properties(chip, fwnode,
> + &max_brightness, &brightness);
> + if (ret)
> + return ret;
> +
> + ret = fwnode_property_read_u32(fwnode, "color", &group_color);
> + if (ret)
> + return dev_err_probe(chip->dev, ret,
> + "failed to read color for %pfw\n", fwnode);
> +
> + if (group_color != LED_COLOR_ID_RGB &&
> + group_color != LED_COLOR_ID_MULTI)
> + return dev_err_probe(chip->dev, -EINVAL,
> + "invalid multicolor LED color %u\n",
> + group_color);
> +
> + has_group_reg = fwnode_property_present(fwnode, "reg");
> + if (has_group_reg) {
> + ret = fwnode_property_read_u32(fwnode, "reg", &group_reg);
> + if (ret)
> + return dev_err_probe(chip->dev, ret,
> + "failed to read group index for %pfw\n",
> + fwnode);
> + }
> +
> + count = fwnode_get_child_node_count(fwnode);
> + if (!count || count > LED_COLOR_ID_MAX)
> + return dev_err_probe(chip->dev, -EINVAL,
> + "invalid component count %u for %pfw\n",
> + count, fwnode);
> +
> + subleds = devm_kcalloc(chip->dev, count, sizeof(*subleds), GFP_KERNEL);
> + if (!subleds)
> + return -ENOMEM;
> + bitmap_zero(color_map, LED_COLOR_ID_MAX);
> +
> + fwnode_for_each_child_node_scoped(fwnode, child) {
> + u32 color;
> +
> + ret = is32fl3207_validate_component(chip, child);
> + if (ret)
> + return ret;
> +
> + ret = fwnode_property_read_u32(child, "color", &color);
> + if (ret)
> + return dev_err_probe(chip->dev, ret,
> + "failed to read color for %pfw\n",
> + child);
> +
> + if (color >= LED_COLOR_ID_MAX || color == LED_COLOR_ID_MULTI ||
> + color == LED_COLOR_ID_RGB)
> + return dev_err_probe(chip->dev, -EINVAL,
> + "invalid component color %u\n",
> + color);
> + if (test_and_set_bit(color, color_map))
> + return dev_err_probe(chip->dev, -EINVAL,
> + "component color %u is used more than once\n",
> + color);
> +
> + ret = is32fl3207_configure_channel(chip, child,
> + &subleds[i].channel);
> + if (ret)
> + return ret;
> +
> + subleds[i].color_index = color;
> + subleds[i].intensity = max_brightness;
> + subleds[i].max_intensity = 0;
> + first_channel = min(first_channel, subleds[i].channel);
> + i++;
> + }
> +
> + if (has_group_reg && group_reg != first_channel)
> + return dev_err_probe(chip->dev, -EINVAL,
> + "group index %u does not match first channel %u\n",
> + group_reg, first_channel);
> +
> + led->chip = chip;
> + led->led_cdev = &led->mcdev.led_cdev;
> + led->mcdev.num_colors = count;
> + led->mcdev.subled_info = subleds;
> + led->mcdev.led_cdev.brightness = brightness;
> + led->mcdev.led_cdev.max_brightness = max_brightness;
> + led->mcdev.led_cdev.brightness_set_blocking =
> + is32fl3207_mc_brightness_set;
> +
> + ret = is32fl3207_mc_brightness_set(&led->mcdev.led_cdev,
> + brightness);
> + if (ret)
> + return ret;
> +
> + return devm_led_classdev_multicolor_register_ext(chip->dev, &led->mcdev,
> + &init_data);
> +}
> +
> +static int is32fl3207_register_led(struct is32fl3207 *chip,
> + struct fwnode_handle *fwnode,
> + struct is32fl3207_led *led)
> +{
> + unsigned int count = fwnode_get_child_node_count(fwnode);
> + bool has_color = fwnode_property_present(fwnode, "color");
> + u32 color = LED_COLOR_ID_MAX;
> + int ret;
> +
> + if (has_color) {
> + ret = fwnode_property_read_u32(fwnode, "color", &color);
> + if (ret)
> + return dev_err_probe(chip->dev, ret,
> + "failed to read color for %pfw\n",
> + fwnode);
> + }
> +
> + if (color == LED_COLOR_ID_RGB || color == LED_COLOR_ID_MULTI) {
> + if (!count)
> + return dev_err_probe(chip->dev, -EINVAL,
> + "multicolor LED %pfw has no components\n",
> + fwnode);
> +
> + return is32fl3207_register_multicolor(chip, fwnode, led);
> + }
> +
> + if (count)
> + return dev_err_probe(chip->dev, -EINVAL,
> + "single LED %pfw must not have components\n",
> + fwnode);
> +
> + return is32fl3207_register_single(chip, fwnode, led);
> +}
> +
> +static int is32fl3207_clear_retained_scaling(struct is32fl3207 *chip)
> +{
> + u8 scaling[IS32FL3207_NUM_CHANNELS] = { };
> + int ret;
> +
> + ret = regmap_write(chip->regmap, IS32FL3207_REG_CONTROL, 0);
> + if (ret)
> + return ret;
> +
> + return regmap_bulk_write(chip->regmap,
> + IS32FL3207_REG_SCALING(0), scaling,
> + sizeof(scaling));
> +}
> +
> +static int is32fl3207_hw_init(struct is32fl3207 *chip)
> +{
> + u8 scaling[IS32FL3207_NUM_CHANNELS] = { };
> + u8 pwm[2 * IS32FL3207_NUM_CHANNELS] = { };
Why 2? Define?
> + int disable_ret;
> + int ret;
> +
> + /* Software reset requires normal operation (SSD = 1). */
> + ret = regmap_write(chip->regmap, IS32FL3207_REG_CONTROL,
> + IS32FL3207_CONTROL_ENABLE);
> + if (ret)
> + return ret;
> +
> + ret = regmap_write(chip->regmap, IS32FL3207_REG_RESET, 0);
> + if (ret)
> + return ret;
> + usleep_range(200, 300);
> +
> + ret = regmap_write(chip->regmap, IS32FL3207_REG_CONTROL, 0);
> + if (ret)
> + return ret;
> +
> + ret = regmap_write(chip->regmap, IS32FL3207_REG_GLOBAL_CURRENT,
> + IS32FL3207_GLOBAL_CURRENT_MAX);
> + if (ret)
> + return ret;
> +
> + ret = regmap_bulk_write(chip->regmap, IS32FL3207_REG_SCALING(0),
> + scaling, sizeof(scaling));
> + if (ret)
> + return ret;
> +
> + ret = regmap_bulk_write(chip->regmap, IS32FL3207_REG_PWM_LOW(0), pwm,
> + sizeof(pwm));
> + if (ret)
> + return ret;
> +
> + /* PWM data can be latched only in normal operation. */
> + ret = regmap_write(chip->regmap, IS32FL3207_REG_CONTROL,
> + IS32FL3207_CONTROL_ENABLE);
> + if (ret)
> + return ret;
> +
> + ret = regmap_write(chip->regmap, IS32FL3207_REG_PWM_UPDATE, 0);
> + disable_ret = regmap_write(chip->regmap, IS32FL3207_REG_CONTROL, 0);
> +
> + return ret ?: disable_ret;
> +}
> +
> +static int is32fl3207_enable(struct is32fl3207 *chip)
> +{
> + int ret;
> +
> + guard(mutex)(&chip->lock);
> +
> + ret = regmap_write(chip->regmap, IS32FL3207_REG_CONTROL,
> + IS32FL3207_CONTROL_ENABLE);
> + if (ret)
> + return ret;
> +
> + ret = regmap_write(chip->regmap, IS32FL3207_REG_PWM_UPDATE, 0);
> + if (ret)
> + regmap_write(chip->regmap, IS32FL3207_REG_CONTROL, 0);
Needs a comment. What does this fall-back do?
> +
> + return ret;
> +}
> +
> +static void is32fl3207_disable_locked(struct is32fl3207 *chip)
> +{
> + regmap_write(chip->regmap, IS32FL3207_REG_CONTROL, 0);
> + if (chip->enable_gpio)
> + gpiod_set_value_cansleep(chip->enable_gpio, 0);
> +}
> +
> +static void is32fl3207_disable(void *data)
> +{
> + struct is32fl3207 *chip = data;
> +
> + guard(mutex)(&chip->lock);
> + chip->shutting_down = true;
> + is32fl3207_disable_locked(chip);
> +}
> +
> +static const struct regmap_config is32fl3207_regmap_config = {
> + .reg_bits = 8,
> + .val_bits = 8,
> + .max_register = IS32FL3207_REG_RESET,
> +};
> +
> +static int is32fl3207_probe(struct i2c_client *client)
> +{
> + struct device *dev = &client->dev;
> + struct is32fl3207 *ddata;
This is confusing - ddata or chip, pick one and use one throughout.
Suggest you use chip here in LEDs, ddata elsewhere.
> + unsigned int count;
> + unsigned int i = 0;
> + u32 riset_ohms;
> + int ret;
> +
> + count = device_get_child_node_count(dev);
> + if (!count || count > IS32FL3207_NUM_CHANNELS)
> + return dev_err_probe(dev, -EINVAL,
> + "invalid LED count %u\n", count);
> +
> + ddata = devm_kzalloc(dev, struct_size(ddata, leds, count), GFP_KERNEL);
> + if (!ddata)
> + return -ENOMEM;
> +
> + ddata->dev = dev;
> + ddata->num_leds = count;
> + i2c_set_clientdata(client, ddata);
> +
> + ret = device_property_read_u32(dev, "issi,riset-ohms", &riset_ohms);
> + if (ret)
> + return dev_err_probe(dev, ret, "failed to read RISET value\n");
> +
> + if (riset_ohms < 2000)
> + return dev_err_probe(dev, -EINVAL,
> + "RISET value %u is below 2000 ohms\n",
> + riset_ohms);
> +
> + ddata->output_max_microamp = div_u64(IS32FL3207_CURRENT_NUMERATOR,
> + riset_ohms);
> + if (!ddata->output_max_microamp)
> + return dev_err_probe(dev, -EINVAL,
> + "RISET value %u is too large\n",
> + riset_ohms);
> +
> + ddata->enable_gpio = devm_gpiod_get_optional(dev, "enable",
> + GPIOD_OUT_LOW);
> + if (IS_ERR(ddata->enable_gpio))
> + return dev_err_probe(dev, PTR_ERR(ddata->enable_gpio),
> + "failed to get enable GPIO\n");
> +
> + ddata->regmap = devm_regmap_init_i2c(client,
> + &is32fl3207_regmap_config);
> + if (IS_ERR(ddata->regmap))
> + return dev_err_probe(dev, PTR_ERR(ddata->regmap),
> + "failed to allocate register map\n");
> +
> + ret = devm_mutex_init(dev, &ddata->lock);
> + if (ret)
> + return ret;
> +
> + ret = devm_regulator_get_enable_optional(dev, "vcc");
> + if (ret && ret != -ENODEV)
> + return dev_err_probe(dev, ret,
> + "failed to enable VCC regulator\n");
> +
> + ret = devm_add_action_or_reset(dev, is32fl3207_disable, ddata);
> + if (ret)
> + return ret;
> +
> + /* Let VCC settle while SDB keeps the outputs disabled. */
> + usleep_range(1000, 2000);
> +
> + /*
> + * Registers remain accessible with SDB low. Clear retained scaling
> + * before releasing hardware shutdown.
> + */
> + ret = is32fl3207_clear_retained_scaling(ddata);
> + if (ret)
> + return dev_err_probe(dev, ret,
> + "failed to clear retained current scaling\n");
> +
> + if (ddata->enable_gpio)
> + gpiod_set_value_cansleep(ddata->enable_gpio, 1);
> +
> + /* The SDB rising edge resets the I2C interface; allow it to settle. */
> + usleep_range(1000, 2000);
> +
> + ret = is32fl3207_hw_init(ddata);
> + if (ret)
> + return dev_err_probe(dev, ret,
> + "failed to initialize controller\n");
> +
> + device_for_each_child_node_scoped(dev, child) {
> + struct is32fl3207_led *led = &ddata->leds[i];
> +
> + ret = is32fl3207_register_led(ddata, child, led);
> + if (ret)
> + return ret;
> +
> + i++;
> + }
> +
> + ret = is32fl3207_enable(ddata);
> + if (ret)
> + return dev_err_probe(dev, ret, "failed to enable controller\n");
> +
> + return 0;
> +}
> +
> +static void is32fl3207_shutdown(struct i2c_client *client)
> +{
> + struct is32fl3207 *chip = i2c_get_clientdata(client);
> + bool retain_state = false;
> + unsigned int i;
> + int ret = 0;
> +
> + guard(mutex)(&chip->lock);
> + chip->shutting_down = true;
> +
> + for (i = 0; i < chip->num_leds; i++)
Needs braces.
> + if (chip->leds[i].led_cdev->flags & LED_RETAIN_AT_SHUTDOWN) {
> + retain_state = true;
> + break;
> + }
> +
> + if (!retain_state) {
> + is32fl3207_disable_locked(chip);
> + return;
> + }
> +
> + for (i = 0; i < chip->num_leds; i++) {
> + struct led_classdev *cdev = chip->leds[i].led_cdev;
> +
> + if (cdev->flags & LED_RETAIN_AT_SHUTDOWN)
> + continue;
Nit: '\n'
> + ret = is32fl3207_turn_off_locked(chip, &chip->leds[i]);
> +
> + if (ret) {
> + dev_warn(chip->dev,
> + "failed to turn off LEDs during shutdown: %d\n",
> + ret);
> + break;
> + }
> + }
> +}
> +
> +static const struct of_device_id is32fl3207_of_match[] = {
> + { .compatible = "issi,is32fl3207" },
> + { }
> +};
> +MODULE_DEVICE_TABLE(of, is32fl3207_of_match);
> +
> +static const struct i2c_device_id is32fl3207_id[] = {
> + { .name = "is32fl3207" },
> + { }
> +};
> +MODULE_DEVICE_TABLE(i2c, is32fl3207_id);
> +
> +static struct i2c_driver is32fl3207_driver = {
> + .driver = {
> + .name = "is32fl3207",
> + .of_match_table = is32fl3207_of_match,
> + },
> + .probe = is32fl3207_probe,
> + .shutdown = is32fl3207_shutdown,
> + .id_table = is32fl3207_id,
> +};
> +module_i2c_driver(is32fl3207_driver);
> +
> +MODULE_AUTHOR("Ahmad Byagowi <ahmadexp@xxxxxxxxx>");
> +MODULE_DESCRIPTION("Lumissil IS32FL3207 LED controller driver");
> +MODULE_LICENSE("GPL");
> --
> 2.50.1 (Apple Git-155)
>
>
--
Lee Jones