Message-Id: <20250228-leds-tps6131x-v1-2-d1071d90f9ea@emfend.at>
Date: Fri, 28 Feb 2025 11:31:24 +0100
From: Matthias Fend <matthias.fend@...end.at>
To: Pavel Machek <pavel@....cz>, Lee Jones <lee@...nel.org>, 
 Rob Herring <robh@...nel.org>, Krzysztof Kozlowski <krzk+dt@...nel.org>, 
 Conor Dooley <conor+dt@...nel.org>
Cc: linux-leds@...r.kernel.org, devicetree@...r.kernel.org, 
 linux-kernel@...r.kernel.org, Matthias Fend <matthias.fend@...end.at>, 
 bsp-development.geo@...ca-geosystems.com
Subject: [PATCH 2/2] leds: tps6131x: add support for Texas Instruments
 TPS6131X flash LED driver

The TPS61310/TPS61311 is a flash LED driver with I2C interface. Its power
stage is capable of supplying a maximum total current of roughly 1500mA.
The TPS6131x provides three constant-current sinks, capable of sinking up
to 2 × 400mA (LED1 and LED3) and 800mA (LED2) in flash mode. In torch mode
each sink (LED1, LED2, LED3) supports currents up to 175mA.

Signed-off-by: Matthias Fend <matthias.fend@...end.at>
---
 MAINTAINERS                        |   7 +
 drivers/leds/flash/Kconfig         |  11 +
 drivers/leds/flash/Makefile        |   1 +
 drivers/leds/flash/leds-tps6131x.c | 798 +++++++++++++++++++++++++++++++++++++
 4 files changed, 817 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 0fa7c5728f1e64d031f4a47b6fce1db484ce0fc2..d2ca840647b566cfee4d8ded1f787e32be4aa163 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -23225,6 +23225,13 @@ F:	Documentation/devicetree/bindings/hwmon/ti,tps23861.yaml
 F:	Documentation/hwmon/tps23861.rst
 F:	drivers/hwmon/tps23861.c
 
+TEXAS INSTRUMENTS TPS6131X FLASH LED DRIVER
+M:	Matthias Fend <matthias.fend@...end.at>
+L:	linux-leds@...r.kernel.org
+S:	Maintained
+F:	Documentation/devicetree/bindings/leds/ti,tps6131x.yaml
+F:	drivers/leds/flash/leds-tps6131x.c
+
 TEXAS INSTRUMENTS' DAC7612 DAC DRIVER
 M:	Ricardo Ribalda <ribalda@...nel.org>
 L:	linux-iio@...r.kernel.org
diff --git a/drivers/leds/flash/Kconfig b/drivers/leds/flash/Kconfig
index f39f0bfe6eefcd376405d9d35dc36e323a485002..55ca663ca506ad8be627f58f6d6308368ea2b928 100644
--- a/drivers/leds/flash/Kconfig
+++ b/drivers/leds/flash/Kconfig
@@ -132,4 +132,15 @@ config LEDS_SY7802
 
 	  This driver can be built as a module, it will be called "leds-sy7802".
 
+config LEDS_TPS6131X
+	tristate "LED support for TI TPS6131x flash LED driver"
+	depends on I2C && OF
+	depends on GPIOLIB
+	select REGMAP_I2C
+	help
+	  This option enables support for Texas Instruments TPS61310/TPS61311
+	  flash LED driver.
+
+	  This driver can be built as a module, it will be called "leds-tps6131x".
+
 endif # LEDS_CLASS_FLASH
diff --git a/drivers/leds/flash/Makefile b/drivers/leds/flash/Makefile
index 48860eeced79513a0ed303e4af3db9bfe9724b7e..712fb737a428e42747e1aa339058dc4306ade9c8 100644
--- a/drivers/leds/flash/Makefile
+++ b/drivers/leds/flash/Makefile
@@ -12,3 +12,4 @@ obj-$(CONFIG_LEDS_RT4505)	+= leds-rt4505.o
 obj-$(CONFIG_LEDS_RT8515)	+= leds-rt8515.o
 obj-$(CONFIG_LEDS_SGM3140)	+= leds-sgm3140.o
 obj-$(CONFIG_LEDS_SY7802)	+= leds-sy7802.o
+obj-$(CONFIG_LEDS_TPS6131X)	+= leds-tps6131x.o
diff --git a/drivers/leds/flash/leds-tps6131x.c b/drivers/leds/flash/leds-tps6131x.c
new file mode 100644
index 0000000000000000000000000000000000000000..5fca542ac88da1db755a75e982dee8e3dde06373
--- /dev/null
+++ b/drivers/leds/flash/leds-tps6131x.c
@@ -0,0 +1,798 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Texas Instruments TPS61310/TPS61311 flash LED driver with I2C interface
+ *
+ * Copyright 2025 Matthias Fend <matthias.fend@...end.at>
+ */
+
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/led-class-flash.h>
+#include <linux/leds.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <media/v4l2-flash-led-class.h>
+
+/* Registers */
+
+#define TPS6131X_REG_0				0x00
+#define TPS6131X_REG_0_RESET			BIT(7)
+#define TPS6131X_REG_0_DCLC13			GENMASK(5, 3)
+#define TPS6131X_REG_0_DCLC13_SHIFT		3
+#define TPS6131X_REG_0_DCLC2			GENMASK(2, 0)
+#define TPS6131X_REG_0_DCLC2_SHIFT		0
+
+#define TPS6131X_REG_1				0x01
+#define TPS6131X_REG_1_MODE			GENMASK(7, 6)
+#define TPS6131X_REG_1_MODE_SHIFT		6
+#define TPS6131X_REG_1_FC2			GENMASK(5, 0)
+#define TPS6131X_REG_1_FC2_SHIFT		0
+
+#define TPS6131X_REG_2				0x02
+#define TPS6131X_REG_2_MODE			GENMASK(7, 6)
+#define TPS6131X_REG_2_MODE_SHIFT		6
+#define TPS6131X_REG_2_ENVM			BIT(5)
+#define TPS6131X_REG_2_FC13			GENMASK(4, 0)
+#define TPS6131X_REG_2_FC13_SHIFT		0
+
+#define TPS6131X_REG_3				0x03
+#define TPS6131X_REG_3_STIM			GENMASK(7, 5)
+#define TPS6131X_REG_3_STIM_SHIFT		5
+#define TPS6131X_REG_3_HPFL			BIT(4)
+#define TPS6131X_REG_3_SELSTIM_TO		BIT(3)
+#define TPS6131X_REG_3_STT			BIT(2)
+#define TPS6131X_REG_3_SFT			BIT(1)
+#define TPS6131X_REG_3_TXMASK			BIT(0)
+
+#define TPS6131X_REG_4				0x04
+#define TPS6131X_REG_4_PG			BIT(7)
+#define TPS6131X_REG_4_HOTDIE_HI		BIT(6)
+#define TPS6131X_REG_4_HOTDIE_LO		BIT(5)
+#define TPS6131X_REG_4_ILIM			BIT(4)
+#define TPS6131X_REG_4_INDC			GENMASK(3, 0)
+#define TPS6131X_REG_4_SHIFT			0
+
+#define TPS6131X_REG_5				0x05
+#define TPS6131X_REG_5_SELFCAL			BIT(7)
+#define TPS6131X_REG_5_ENPSM			BIT(6)
+#define TPS6131X_REG_5_STSTRB1_DIR		BIT(5)
+#define TPS6131X_REG_5_GPIO			BIT(4)
+#define TPS6131X_REG_5_GPIOTYPE			BIT(3)
+#define TPS6131X_REG_5_ENLED3			BIT(2)
+#define TPS6131X_REG_5_ENLED2			BIT(1)
+#define TPS6131X_REG_5_ENLED1			BIT(0)
+
+#define TPS6131X_REG_6				0x06
+#define TPS6131X_REG_6_ENTS			BIT(7)
+#define TPS6131X_REG_6_LEDHOT			BIT(6)
+#define TPS6131X_REG_6_LEDWARN			BIT(5)
+#define TPS6131X_REG_6_LEDHDR			BIT(4)
+#define TPS6131X_REG_6_OV			GENMASK(3, 0)
+#define TPS6131X_REG_6_OV_SHIFT			0
+
+#define TPS6131X_REG_7				0x07
+#define TPS6131X_REG_7_ENBATMON			BIT(7)
+#define TPS6131X_REG_7_BATDROOP			GENMASK(6, 4)
+#define TPS6131X_REG_7_BATDROOP_SHIFT		4
+#define TPS6131X_REG_7_REVID			GENMASK(2, 0)
+#define TPS6131X_REG_7_REVID_SHIFT		0
+
+/* Constants */
+
+#define TPS6131X_MAX_CHANNELS			3
+
+#define TPS6131X_FLASH_MAX_I_CHAN13_MA		400
+#define TPS6131X_FLASH_MAX_I_CHAN2_MA		800
+#define TPS6131X_FLASH_STEP_I_MA		25
+
+#define TPS6131X_TORCH_MAX_I_CHAN13_MA		175
+#define TPS6131X_TORCH_MAX_I_CHAN2_MA		175
+#define TPS6131X_TORCH_STEP_I_MA		25
+
+#define TPS6131X_TORCH_REFRESH_INTERVAL_JIFFIES msecs_to_jiffies(10000)
+
+struct tps6131x {
+	struct i2c_client *client;
+	struct regmap *regmap;
+	struct gpio_desc *reset_gpio;
+	struct mutex lock; /* */
+	struct delayed_work torch_refresh_work;
+	bool valley_current_limit;
+	bool chan1_en;
+	bool chan2_en;
+	bool chan3_en;
+	struct fwnode_handle *led_node;
+	u32 max_flash_current_ma;
+	u32 step_flash_current_ma;
+	u32 max_torch_current_ma;
+	u32 step_torch_current_ma;
+	u32 max_timeout_us;
+	struct led_classdev_flash fled_cdev;
+	struct v4l2_flash *v4l2_flash;
+};
+
+static struct tps6131x *fled_cdev_to_tps6131x(struct led_classdev_flash *fled_cdev)
+{
+	return container_of(fled_cdev, struct tps6131x, fled_cdev);
+}
+
+static const struct reg_default tps6131x_regmap_defaults[] = {
+	{ TPS6131X_REG_0, 0x0A },
+	{ TPS6131X_REG_1, 0x10 },
+	{ TPS6131X_REG_2, 0x08 },
+	{ TPS6131X_REG_3, 0xC1 },
+	{ TPS6131X_REG_4, 0x00 },
+	{ TPS6131X_REG_5, 0x6A },
+	{ TPS6131X_REG_6, 0x00 },
+	{ TPS6131X_REG_7, 0x46 },
+};
+
+/*
+ * These registers contain flags that are reset when read. Ensure that these registers are not read
+ * outside of a call from the driver.
+ */
+static bool tps6131x_regmap_precious(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case TPS6131X_REG_3:
+	case TPS6131X_REG_4:
+	case TPS6131X_REG_6:
+		return true;
+	default:
+		return false;
+	}
+}
+
+static const struct regmap_config tps6131x_regmap = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = TPS6131X_REG_7,
+	.reg_defaults = tps6131x_regmap_defaults,
+	.num_reg_defaults = ARRAY_SIZE(tps6131x_regmap_defaults),
+	.cache_type = REGCACHE_FLAT,
+	.precious_reg = &tps6131x_regmap_precious,
+};
+
+struct tps6131x_timer_config {
+	u8 val;
+	u8 range;
+	u32 time_us;
+};
+
+static const struct tps6131x_timer_config tps6131x_timer_configs[] = {
+	{ .val = 0, .range = 1, .time_us = 5300 },
+	{ .val = 1, .range = 1, .time_us = 10700 },
+	{ .val = 2, .range = 1, .time_us = 16000 },
+	{ .val = 3, .range = 1, .time_us = 21300 },
+	{ .val = 4, .range = 1, .time_us = 26600 },
+	{ .val = 5, .range = 1, .time_us = 32000 },
+	{ .val = 6, .range = 1, .time_us = 37300 },
+	{ .val = 0, .range = 0, .time_us = 68200 },
+	{ .val = 7, .range = 1, .time_us = 71500 },
+	{ .val = 1, .range = 0, .time_us = 102200 },
+	{ .val = 2, .range = 0, .time_us = 136300 },
+	{ .val = 3, .range = 0, .time_us = 170400 },
+	{ .val = 4, .range = 0, .time_us = 204500 },
+	{ .val = 5, .range = 0, .time_us = 340800 },
+	{ .val = 6, .range = 0, .time_us = 579300 },
+	{ .val = 7, .range = 0, .time_us = 852000 },
+};
+
+static const struct tps6131x_timer_config *tps6131x_find_closest_timer_config(u32 timeout_us)
+{
+	const struct tps6131x_timer_config *timer_config = &tps6131x_timer_configs[0];
+	u32 diff, min_diff = U32_MAX;
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(tps6131x_timer_configs); i++) {
+		diff = abs(tps6131x_timer_configs[i].time_us - timeout_us);
+		if (diff < min_diff) {
+			timer_config = &tps6131x_timer_configs[i];
+			min_diff = diff;
+			if (!min_diff)
+				break;
+		}
+	}
+
+	return timer_config;
+}
+
+static int tps6131x_reset_chip(struct tps6131x *tps6131x)
+{
+	int ret;
+
+	if (IS_ERR_OR_NULL(tps6131x->reset_gpio)) {
+		ret = regmap_update_bits(tps6131x->regmap, TPS6131X_REG_0, TPS6131X_REG_0_RESET,
+					 TPS6131X_REG_0_RESET);
+		if (ret)
+			return ret;
+
+		ret = regmap_update_bits(tps6131x->regmap, TPS6131X_REG_0, TPS6131X_REG_0_RESET, 0);
+		if (ret)
+			return ret;
+	} else {
+		gpiod_set_value_cansleep(tps6131x->reset_gpio, 1);
+		fsleep(10);
+		gpiod_set_value_cansleep(tps6131x->reset_gpio, 0);
+	}
+
+	return 0;
+}
+
+static int tps6131x_init_chip(struct tps6131x *tps6131x)
+{
+	u32 reg4, reg5, reg6;
+	int ret;
+
+	reg4 = tps6131x->valley_current_limit ? TPS6131X_REG_4_ILIM : 0;
+	ret = regmap_write(tps6131x->regmap, TPS6131X_REG_4, reg4);
+	if (ret)
+		return ret;
+
+	reg5 = TPS6131X_REG_5_ENPSM | TPS6131X_REG_5_STSTRB1_DIR | TPS6131X_REG_5_GPIOTYPE;
+	if (tps6131x->chan1_en)
+		reg5 |= TPS6131X_REG_5_ENLED1;
+
+	if (tps6131x->chan2_en)
+		reg5 |= TPS6131X_REG_5_ENLED2;
+
+	if (tps6131x->chan3_en)
+		reg5 |= TPS6131X_REG_5_ENLED3;
+	ret = regmap_write(tps6131x->regmap, TPS6131X_REG_5, reg5);
+	if (ret)
+		return ret;
+
+	reg6 = TPS6131X_REG_6_ENTS;
+	ret = regmap_write(tps6131x->regmap, TPS6131X_REG_6, reg6);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+enum tps6131x_mode {
+	TPS6131X_MODE_SHUTDOWN,
+	TPS6131X_MODE_TORCH,
+	TPS6131X_MODE_FLASH,
+};
+
+static int tps6131x_set_mode(struct tps6131x *tps6131x, enum tps6131x_mode mode, bool force)
+{
+	u8 val;
+
+	switch (mode) {
+	case TPS6131X_MODE_FLASH:
+		val = 2 << TPS6131X_REG_1_MODE_SHIFT;
+		break;
+	case TPS6131X_MODE_TORCH:
+		val = 1 << TPS6131X_REG_1_MODE_SHIFT;
+		break;
+	case TPS6131X_MODE_SHUTDOWN:
+	default:
+		val = 0 << TPS6131X_REG_1_MODE_SHIFT;
+		break;
+	}
+
+	return regmap_update_bits_base(tps6131x->regmap, TPS6131X_REG_1, TPS6131X_REG_1_MODE, val,
+				       NULL, false, force);
+}
+
+static void tps6131x_torch_refresh_handler(struct work_struct *work)
+{
+	struct tps6131x *tps6131x = container_of(work, struct tps6131x, torch_refresh_work.work);
+
+	guard(mutex)(&tps6131x->lock);
+
+	tps6131x_set_mode(tps6131x, TPS6131X_MODE_TORCH, true);
+
+	schedule_delayed_work(&tps6131x->torch_refresh_work,
+			      TPS6131X_TORCH_REFRESH_INTERVAL_JIFFIES);
+}
+
+static int tps6131x_brightness_set(struct led_classdev *cdev, enum led_brightness brightness)
+{
+	struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(cdev);
+	struct tps6131x *tps6131x = fled_cdev_to_tps6131x(fled_cdev);
+	int ret;
+	u8 reg0;
+	u32 steps_remaining, steps_chan13, steps_chan2;
+	unsigned int num_chans = tps6131x->chan1_en + tps6131x->chan2_en + tps6131x->chan3_en;
+
+	cancel_delayed_work_sync(&tps6131x->torch_refresh_work);
+
+	guard(mutex)(&tps6131x->lock);
+
+	/*
+	 * The brightness parameter uses the number of current steps as the unit (not the current
+	 * value itself). Since the reported step size can vary depending on the configuration,
+	 * this value must be converted into actual register steps.
+	 */
+	steps_remaining = (brightness * tps6131x->step_torch_current_ma) / TPS6131X_TORCH_STEP_I_MA;
+
+	/*
+	 * The currents are distributed as evenly as possible across the activated channels.
+	 * Since channels 1 and 3 share the same register setting, they always use the same current
+	 * value. Channel 2 supports higher currents and thus takes over the remaining additional
+	 * portion that cannot be covered by the other channels.
+	 */
+	steps_chan13 = min_t(u32, steps_remaining / num_chans,
+			     TPS6131X_TORCH_MAX_I_CHAN13_MA / TPS6131X_TORCH_STEP_I_MA);
+	if (tps6131x->chan1_en)
+		steps_remaining -= steps_chan13;
+	if (tps6131x->chan3_en)
+		steps_remaining -= steps_chan13;
+
+	steps_chan2 = min_t(u32, steps_remaining,
+			    TPS6131X_TORCH_MAX_I_CHAN2_MA / TPS6131X_TORCH_STEP_I_MA);
+
+	reg0 = (steps_chan13 << TPS6131X_REG_0_DCLC13_SHIFT) |
+	       (steps_chan2 << TPS6131X_REG_0_DCLC2_SHIFT);
+	ret = regmap_update_bits(tps6131x->regmap, TPS6131X_REG_0,
+				 TPS6131X_REG_0_DCLC13 | TPS6131X_REG_0_DCLC2, reg0);
+	if (ret < 0)
+		return ret;
+
+	ret = tps6131x_set_mode(tps6131x, brightness ? TPS6131X_MODE_TORCH : TPS6131X_MODE_SHUTDOWN,
+				true);
+	if (ret < 0)
+		return ret;
+
+	/*
+	 * In order to use both the flash and the video light functions purely via the I2C
+	 * interface, STRB1 must be low. If STRB1 is low, then the video light watchdog timer
+	 * is also active, which puts the device into the shutdown state after around 13 seconds.
+	 * To prevent this, the mode must be refreshed within the watchdog timeout.
+	 */
+	if (brightness)
+		schedule_delayed_work(&tps6131x->torch_refresh_work,
+				      TPS6131X_TORCH_REFRESH_INTERVAL_JIFFIES);
+
+	return 0;
+}
+
+static int tps6131x_strobe_set(struct led_classdev_flash *fled_cdev, bool state)
+{
+	struct tps6131x *tps6131x = fled_cdev_to_tps6131x(fled_cdev);
+	int ret;
+
+	guard(mutex)(&tps6131x->lock);
+
+	ret = tps6131x_set_mode(tps6131x, state ? TPS6131X_MODE_FLASH : TPS6131X_MODE_SHUTDOWN,
+				true);
+	if (ret < 0)
+		return ret;
+
+	if (state) {
+		ret = regmap_update_bits_base(tps6131x->regmap, TPS6131X_REG_3, TPS6131X_REG_3_SFT,
+					      TPS6131X_REG_3_SFT, NULL, false, true);
+		if (ret)
+			return ret;
+	}
+
+	ret = regmap_update_bits_base(tps6131x->regmap, TPS6131X_REG_3, TPS6131X_REG_3_SFT, 0, NULL,
+				      false, true);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static int tps6131x_flash_brightness_set(struct led_classdev_flash *fled_cdev, u32 brightness)
+{
+	struct tps6131x *tps6131x = fled_cdev_to_tps6131x(fled_cdev);
+	u32 steps_remaining, steps_chan13, steps_chan2, num_chans;
+	int ret;
+
+	guard(mutex)(&tps6131x->lock);
+
+	steps_remaining = brightness / TPS6131X_FLASH_STEP_I_MA;
+	num_chans = tps6131x->chan1_en + tps6131x->chan2_en + tps6131x->chan3_en;
+
+	steps_chan13 = min_t(u32, steps_remaining / num_chans,
+			     TPS6131X_FLASH_MAX_I_CHAN13_MA / TPS6131X_FLASH_STEP_I_MA);
+	if (tps6131x->chan1_en)
+		steps_remaining -= steps_chan13;
+	if (tps6131x->chan3_en)
+		steps_remaining -= steps_chan13;
+	steps_chan2 = min_t(u32, steps_remaining,
+			    TPS6131X_FLASH_MAX_I_CHAN2_MA / TPS6131X_FLASH_STEP_I_MA);
+
+	ret = regmap_update_bits(tps6131x->regmap, TPS6131X_REG_2, TPS6131X_REG_2_FC13,
+				 steps_chan13 << TPS6131X_REG_2_FC13_SHIFT);
+	if (ret < 0)
+		return ret;
+
+	ret = regmap_update_bits(tps6131x->regmap, TPS6131X_REG_1, TPS6131X_REG_1_FC2,
+				 steps_chan2 << TPS6131X_REG_1_FC2_SHIFT);
+	if (ret < 0)
+		return ret;
+
+	fled_cdev->brightness.val = brightness;
+
+	return 0;
+}
+
+static int tps6131x_flash_timeout_set(struct led_classdev_flash *fled_cdev, u32 timeout_us)
+{
+	struct tps6131x *tps6131x = fled_cdev_to_tps6131x(fled_cdev);
+	int ret;
+	u8 reg3;
+	const struct tps6131x_timer_config *timer_config;
+
+	guard(mutex)(&tps6131x->lock);
+
+	timer_config = tps6131x_find_closest_timer_config(timeout_us);
+
+	reg3 = timer_config->val << TPS6131X_REG_3_STIM_SHIFT;
+	if (timer_config->range)
+		reg3 |= TPS6131X_REG_3_SELSTIM_TO;
+
+	ret = regmap_update_bits(tps6131x->regmap, TPS6131X_REG_3,
+				 TPS6131X_REG_3_STIM | TPS6131X_REG_3_SELSTIM_TO, reg3);
+	if (ret < 0)
+		return ret;
+
+	fled_cdev->timeout.val = timer_config->time_us;
+
+	return 0;
+}
+
+static int tps6131x_strobe_get(struct led_classdev_flash *fled_cdev, bool *state)
+{
+	struct tps6131x *tps6131x = fled_cdev_to_tps6131x(fled_cdev);
+	unsigned int reg3;
+	int ret;
+
+	guard(mutex)(&tps6131x->lock);
+
+	ret = regmap_read_bypassed(tps6131x->regmap, TPS6131X_REG_3, &reg3);
+	if (ret)
+		return ret;
+
+	*state = !!(reg3 & TPS6131X_REG_3_SFT);
+
+	return 0;
+}
+
+static int tps6131x_flash_fault_get(struct led_classdev_flash *fled_cdev, u32 *fault)
+{
+	struct tps6131x *tps6131x = fled_cdev_to_tps6131x(fled_cdev);
+	unsigned int reg3, reg4, reg6;
+	int ret;
+
+	*fault = 0;
+
+	ret = regmap_read_bypassed(tps6131x->regmap, TPS6131X_REG_3, &reg3);
+	if (ret < 0)
+		return ret;
+
+	ret = regmap_read_bypassed(tps6131x->regmap, TPS6131X_REG_4, &reg4);
+	if (ret < 0)
+		return ret;
+
+	ret = regmap_read_bypassed(tps6131x->regmap, TPS6131X_REG_6, &reg6);
+	if (ret < 0)
+		return ret;
+
+	if (reg3 & TPS6131X_REG_3_HPFL)
+		*fault |= LED_FAULT_SHORT_CIRCUIT;
+
+	if (reg3 & TPS6131X_REG_3_SELSTIM_TO)
+		*fault |= LED_FAULT_TIMEOUT;
+
+	if (reg4 & TPS6131X_REG_4_HOTDIE_HI)
+		*fault |= LED_FAULT_OVER_TEMPERATURE;
+
+	if (reg6 & (TPS6131X_REG_6_LEDHOT | TPS6131X_REG_6_LEDWARN))
+		*fault |= LED_FAULT_LED_OVER_TEMPERATURE;
+
+	if (!(reg6 & TPS6131X_REG_6_LEDHDR))
+		*fault |= LED_FAULT_UNDER_VOLTAGE;
+
+	if (reg6 & TPS6131X_REG_6_LEDHOT) {
+		ret = regmap_update_bits_base(tps6131x->regmap, TPS6131X_REG_6,
+					      TPS6131X_REG_6_LEDHOT, 0, NULL, false, true);
+		if (ret < 0)
+			return ret;
+	}
+
+	return 0;
+}
+
+static const struct led_flash_ops flash_ops = {
+	.flash_brightness_set = tps6131x_flash_brightness_set,
+	.strobe_set = tps6131x_strobe_set,
+	.strobe_get = tps6131x_strobe_get,
+	.timeout_set = tps6131x_flash_timeout_set,
+	.fault_get = tps6131x_flash_fault_get,
+};
+
+static int tps6131x_parse_node(struct tps6131x *tps6131x)
+{
+	struct device *dev = &tps6131x->client->dev;
+	int ret;
+	u32 current_ua, timeout_us;
+	const struct tps6131x_timer_config *timer_config;
+	u32 flash_max_i_ma, torch_max_i_ma;
+	u32 current_step_multiplier;
+	u32 channels[TPS6131X_MAX_CHANNELS];
+	unsigned int num_channels;
+	int i;
+
+	tps6131x->valley_current_limit = device_property_read_bool(dev, "ti,valley-current-limit");
+
+	tps6131x->led_node = fwnode_get_next_available_child_node(dev->fwnode, NULL);
+	if (!tps6131x->led_node) {
+		dev_err(dev, "Missing LED node\n");
+		return -EINVAL;
+	}
+
+	num_channels = fwnode_property_count_u32(tps6131x->led_node, "led-sources");
+	if (num_channels <= 0) {
+		dev_err(dev, "Failed to read led-sources property\n");
+		return -EINVAL;
+	}
+
+	if (num_channels > TPS6131X_MAX_CHANNELS) {
+		dev_err(dev, "led-sources count %u exceeds maximum channel count %u\n",
+			num_channels, TPS6131X_MAX_CHANNELS);
+		return -EINVAL;
+	}
+
+	ret = fwnode_property_read_u32_array(tps6131x->led_node, "led-sources", channels,
+					     num_channels);
+	if (ret < 0) {
+		dev_err(dev, "Failed to read led-sources property\n");
+		return ret;
+	}
+
+	flash_max_i_ma = 0;
+	torch_max_i_ma = 0;
+	for (i = 0; i < num_channels; i++) {
+		switch (channels[i]) {
+		case 1:
+			tps6131x->chan1_en = true;
+			flash_max_i_ma += TPS6131X_FLASH_MAX_I_CHAN13_MA;
+			torch_max_i_ma += TPS6131X_TORCH_MAX_I_CHAN13_MA;
+			break;
+		case 2:
+			tps6131x->chan2_en = true;
+			flash_max_i_ma += TPS6131X_FLASH_MAX_I_CHAN2_MA;
+			torch_max_i_ma += TPS6131X_TORCH_MAX_I_CHAN2_MA;
+			break;
+		case 3:
+			tps6131x->chan3_en = true;
+			flash_max_i_ma += TPS6131X_FLASH_MAX_I_CHAN13_MA;
+			torch_max_i_ma += TPS6131X_TORCH_MAX_I_CHAN13_MA;
+			break;
+		default:
+			dev_err(dev, "led-source out of range [1-3]\n");
+			return -EINVAL;
+		}
+	}
+
+	/*
+	 * If only channels 1 and 3 are used, the step size is doubled because the two channels
+	 * share the same current control register.
+	 */
+	current_step_multiplier =
+		(tps6131x->chan1_en && tps6131x->chan3_en && !tps6131x->chan2_en) ? 2 : 1;
+	tps6131x->step_flash_current_ma = current_step_multiplier * TPS6131X_FLASH_STEP_I_MA;
+	tps6131x->step_torch_current_ma = current_step_multiplier * TPS6131X_TORCH_STEP_I_MA;
+
+	ret = fwnode_property_read_u32(tps6131x->led_node, "led-max-microamp", &current_ua);
+	if (ret < 0) {
+		dev_err(dev, "Failed to read led-max-microamp property\n");
+		return ret;
+	}
+
+	tps6131x->max_torch_current_ma = current_ua / 1000;
+
+	if (!tps6131x->max_torch_current_ma || tps6131x->max_torch_current_ma > torch_max_i_ma ||
+	    (tps6131x->max_torch_current_ma % tps6131x->step_torch_current_ma)) {
+		dev_err(dev, "led-max-microamp out of range or not a multiple of %u\n",
+			tps6131x->step_torch_current_ma);
+		return -EINVAL;
+	}
+
+	ret = fwnode_property_read_u32(tps6131x->led_node, "flash-max-microamp", &current_ua);
+	if (ret < 0) {
+		dev_err(dev, "Failed to read flash-max-microamp property\n");
+		return ret;
+	}
+
+	tps6131x->max_flash_current_ma = current_ua / 1000;
+
+	if (!tps6131x->max_flash_current_ma || tps6131x->max_flash_current_ma > flash_max_i_ma ||
+	    (tps6131x->max_flash_current_ma % tps6131x->step_flash_current_ma)) {
+		dev_err(dev, "flash-max-microamp out of range or not a multiple of %u\n",
+			tps6131x->step_flash_current_ma);
+		return -EINVAL;
+	}
+
+	ret = fwnode_property_read_u32(tps6131x->led_node, "flash-max-timeout-us", &timeout_us);
+	if (ret < 0) {
+		dev_err(dev, "Failed to read flash-max-timeout-us property\n");
+		return ret;
+	}
+
+	timer_config = tps6131x_find_closest_timer_config(timeout_us);
+	tps6131x->max_timeout_us = timer_config->time_us;
+
+	if (tps6131x->max_timeout_us != timeout_us)
+		dev_warn(dev, "flash-max-timeout-us %u not supported (using %u)\n", timeout_us,
+			 tps6131x->max_timeout_us);
+
+	return 0;
+}
+
+static int tps6131x_led_class_setup(struct tps6131x *tps6131x)
+{
+	struct led_classdev *led_cdev;
+	struct led_flash_setting *setting;
+	struct led_init_data init_data = {};
+	static const struct tps6131x_timer_config *timer_config;
+	int ret;
+
+	tps6131x->fled_cdev.ops = &flash_ops;
+
+	setting = &tps6131x->fled_cdev.timeout;
+	timer_config = tps6131x_find_closest_timer_config(0);
+	setting->min = timer_config->time_us;
+	setting->max = tps6131x->max_timeout_us;
+	setting->step = 1; /* Only some specific time periods are supported. No fixed step size. */
+	setting->val = setting->min;
+
+	setting = &tps6131x->fled_cdev.brightness;
+	setting->min = tps6131x->step_flash_current_ma;
+	setting->max = tps6131x->max_flash_current_ma;
+	setting->step = tps6131x->step_flash_current_ma;
+	setting->val = setting->min;
+
+	led_cdev = &tps6131x->fled_cdev.led_cdev;
+	led_cdev->brightness_set_blocking = tps6131x_brightness_set;
+	led_cdev->max_brightness = tps6131x->max_torch_current_ma;
+	led_cdev->flags |= LED_DEV_CAP_FLASH;
+
+	init_data.fwnode = tps6131x->led_node;
+	init_data.devicename = NULL;
+	init_data.default_label = NULL;
+	init_data.devname_mandatory = false;
+
+	ret = devm_led_classdev_flash_register_ext(&tps6131x->client->dev, &tps6131x->fled_cdev,
+						   &init_data);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+#if IS_ENABLED(CONFIG_V4L2_FLASH_LED_CLASS)
+
+static int tps6131x_flash_external_strobe_set(struct v4l2_flash *v4l2_flash, bool enable)
+{
+	struct led_classdev_flash *fled_cdev = v4l2_flash->fled_cdev;
+	struct tps6131x *tps6131x = fled_cdev_to_tps6131x(fled_cdev);
+
+	guard(mutex)(&tps6131x->lock);
+
+	return tps6131x_set_mode(tps6131x, enable ? TPS6131X_MODE_FLASH : TPS6131X_MODE_SHUTDOWN,
+				 false);
+}
+
+static const struct v4l2_flash_ops tps6131x_v4l2_flash_ops = {
+	.external_strobe_set = tps6131x_flash_external_strobe_set,
+};
+
+static int tps6131x_v4l2_setup(struct tps6131x *tps6131x)
+{
+	struct v4l2_flash_config v4l2_cfg = { 0 };
+	struct led_flash_setting *intensity = &v4l2_cfg.intensity;
+
+	intensity->min = tps6131x->step_torch_current_ma;
+	intensity->max = tps6131x->max_torch_current_ma;
+	intensity->step = tps6131x->step_torch_current_ma;
+	intensity->val = intensity->min;
+
+	strscpy(v4l2_cfg.dev_name, tps6131x->fled_cdev.led_cdev.dev->kobj.name,
+		sizeof(v4l2_cfg.dev_name));
+
+	v4l2_cfg.has_external_strobe = true;
+	v4l2_cfg.flash_faults = LED_FAULT_TIMEOUT | LED_FAULT_OVER_TEMPERATURE |
+				LED_FAULT_SHORT_CIRCUIT | LED_FAULT_UNDER_VOLTAGE |
+				LED_FAULT_LED_OVER_TEMPERATURE;
+
+	tps6131x->v4l2_flash = v4l2_flash_init(&tps6131x->client->dev, tps6131x->led_node,
+					       &tps6131x->fled_cdev, &tps6131x_v4l2_flash_ops,
+					       &v4l2_cfg);
+	if (IS_ERR(tps6131x->v4l2_flash)) {
+		dev_err(&tps6131x->client->dev, "v4l2_flash_init failed\n");
+		return PTR_ERR(tps6131x->v4l2_flash);
+	}
+
+	return 0;
+}
+
+#else
+
+static int tps6131x_v4l2_setup(struct tps6131x *tps6131x)
+{
+	return 0;
+}
+
+#endif
+
+static int tps6131x_probe(struct i2c_client *client)
+{
+	struct tps6131x *tps6131x;
+	int ret;
+
+	tps6131x = devm_kzalloc(&client->dev, sizeof(*tps6131x), GFP_KERNEL);
+	if (!tps6131x)
+		return -ENOMEM;
+
+	tps6131x->client = client;
+	i2c_set_clientdata(client, tps6131x);
+	mutex_init(&tps6131x->lock);
+	INIT_DELAYED_WORK(&tps6131x->torch_refresh_work, tps6131x_torch_refresh_handler);
+
+	ret = tps6131x_parse_node(tps6131x);
+	if (ret)
+		return -ENODEV;
+
+	tps6131x->regmap = devm_regmap_init_i2c(client, &tps6131x_regmap);
+	if (IS_ERR(tps6131x->regmap)) {
+		ret = PTR_ERR(tps6131x->regmap);
+		dev_err(&client->dev, "Failed to allocate register map\n");
+		return ret;
+	}
+
+	tps6131x->reset_gpio = devm_gpiod_get_optional(&client->dev, "reset", GPIOD_OUT_HIGH);
+	ret = tps6131x_reset_chip(tps6131x);
+	if (ret)
+		return dev_err_probe(&client->dev, ret, "Failed to reset LED controller\n");
+
+	ret = tps6131x_init_chip(tps6131x);
+	if (ret)
+		return dev_err_probe(&client->dev, ret, "Failed to initialize LED controller\n");
+
+	ret = tps6131x_led_class_setup(tps6131x);
+	if (ret)
+		return dev_err_probe(&client->dev, ret, "Failed to setup led class\n");
+
+	ret = tps6131x_v4l2_setup(tps6131x);
+	if (ret)
+		return dev_err_probe(&client->dev, ret, "Failed to setup v4l2 flash\n");
+
+	return 0;
+}
+
+static void tps6131x_remove(struct i2c_client *client)
+{
+	struct tps6131x *tps6131x = i2c_get_clientdata(client);
+
+	v4l2_flash_release(tps6131x->v4l2_flash);
+
+	cancel_delayed_work_sync(&tps6131x->torch_refresh_work);
+}
+
+static const struct of_device_id of_tps6131x_leds_match[] = {
+	{ .compatible = "ti,tps61310" },
+	{ .compatible = "ti,tps61311" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, of_tps6131x_leds_match);
+
+static struct i2c_driver tps6131x_i2c_driver = {
+	.driver = {
+		.name = "tps6131x",
+		.of_match_table = of_tps6131x_leds_match,
+	},
+	.probe = tps6131x_probe,
+	.remove = tps6131x_remove,
+};
+module_i2c_driver(tps6131x_i2c_driver);
+
+MODULE_DESCRIPTION("Texas Instruments TPS6131X flash LED driver");
+MODULE_AUTHOR("Matthias Fend <matthias.fend@...end.at>");
+MODULE_LICENSE("GPL");

-- 
2.34.1

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