--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Flash and Torch LED Driver for Samsung S2M series PMICs.
+ *
+ * Copyright (c) 2015 Samsung Electronics Co., Ltd
+ * Copyright (c) 2026 Kaustabh Chakraborty <kauschluss@disroot.org>
+ */
+
+#include <linux/container_of.h>
+#include <linux/led-class-flash.h>
+#include <linux/mfd/samsung/core.h>
+#include <linux/mfd/samsung/s2mu005.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <media/v4l2-flash-led-class.h>
+
+#define MAX_CHANNELS 2
+
+struct s2m_led {
+ struct regmap *regmap;
+ struct led_classdev_flash fled;
+ struct v4l2_flash *v4l2_flash;
+ /*
+ * The mutex object prevents the concurrent access of flash control
+ * registers by the LED and V4L2 subsystems.
+ */
+ struct mutex lock;
+ unsigned int reg_enable;
+ u8 channel;
+ u8 flash_brightness;
+ u8 flash_timeout;
+};
+
+static struct s2m_led *to_s2m_led(struct led_classdev_flash *fled)
+{
+ return container_of(fled, struct s2m_led, fled);
+}
+
+static struct led_classdev_flash *to_s2m_fled(struct led_classdev *cdev)
+{
+ return container_of(cdev, struct led_classdev_flash, led_cdev);
+}
+
+static int s2m_fled_flash_brightness_set(struct led_classdev_flash *fled, u32 brightness)
+{
+ struct s2m_led *led = to_s2m_led(fled);
+ struct led_flash_setting *setting = &fled->brightness;
+
+ mutex_lock(&led->lock);
+ led->flash_brightness = (brightness - setting->min) / setting->step;
+ mutex_unlock(&led->lock);
+
+ return 0;
+}
+
+static int s2m_fled_flash_timeout_set(struct led_classdev_flash *fled, u32 timeout)
+{
+ struct s2m_led *led = to_s2m_led(fled);
+ struct led_flash_setting *setting = &fled->timeout;
+
+ mutex_lock(&led->lock);
+ led->flash_timeout = (timeout - setting->min) / setting->step;
+ mutex_unlock(&led->lock);
+
+ return 0;
+}
+
+#if IS_ENABLED(CONFIG_V4L2_FLASH_LED_CLASS)
+static int s2m_fled_flash_external_strobe_set(struct v4l2_flash *v4l2_flash, bool enable)
+{
+ struct s2m_led *led = to_s2m_led(v4l2_flash->fled_cdev);
+
+ return led->fled.ops->strobe_set(&led->fled, enable);
+}
+
+static const struct v4l2_flash_ops s2m_fled_v4l2_flash_ops = {
+ .external_strobe_set = s2m_fled_flash_external_strobe_set,
+};
+#else
+static const struct v4l2_flash_ops s2m_fled_v4l2_flash_ops;
+#endif
+
+static void s2m_fled_v4l2_flash_release(void *v4l2_flash)
+{
+ v4l2_flash_release(v4l2_flash);
+}
+
+static int s2mu005_fled_torch_brightness_set(struct led_classdev *cdev, enum led_brightness value)
+{
+ struct s2m_led *led = to_s2m_led(to_s2m_fled(cdev));
+ int ret;
+
+ mutex_lock(&led->lock);
+
+ if (!value) {
+ ret = regmap_clear_bits(led->regmap, led->reg_enable,
+ S2MU005_FLED_TORCH_EN(led->channel));
+ if (ret)
+ dev_err(cdev->dev, "failed to disable torch LED\n");
+ goto unlock;
+ }
+
+ ret = regmap_update_bits(led->regmap, S2MU005_REG_FLED_CH_CTRL1(led->channel),
+ S2MU005_FLED_TORCH_IOUT,
+ FIELD_PREP(S2MU005_FLED_TORCH_IOUT, value - 1));
+ if (ret) {
+ dev_err(cdev->dev, "failed to set torch current\n");
+ goto unlock;
+ }
+
+ ret = regmap_set_bits(led->regmap, led->reg_enable, S2MU005_FLED_TORCH_EN(led->channel));
+ if (ret) {
+ dev_err(cdev->dev, "failed to enable torch LED\n");
+ goto unlock;
+ }
+
+unlock:
+ mutex_unlock(&led->lock);
+
+ return ret;
+}
+
+static int s2mu005_fled_flash_strobe_set(struct led_classdev_flash *fled, bool state)
+{
+ struct s2m_led *led = to_s2m_led(fled);
+ int ret;
+
+ mutex_lock(&led->lock);
+
+ ret = regmap_clear_bits(led->regmap, led->reg_enable, S2MU005_FLED_FLASH_EN(led->channel));
+ if (ret) {
+ dev_err(fled->led_cdev.dev, "failed to disable flash LED\n");
+ goto unlock;
+ }
+
+ if (!state)
+ goto unlock;
+
+ ret = regmap_update_bits(led->regmap, S2MU005_REG_FLED_CH_CTRL0(led->channel),
+ S2MU005_FLED_FLASH_IOUT,
+ FIELD_PREP(S2MU005_FLED_FLASH_IOUT, led->flash_brightness));
+ if (ret) {
+ dev_err(fled->led_cdev.dev, "failed to set flash brightness\n");
+ goto unlock;
+ }
+
+ ret = regmap_update_bits(led->regmap, S2MU005_REG_FLED_CH_CTRL3(led->channel),
+ S2MU005_FLED_FLASH_TIMEOUT,
+ FIELD_PREP(S2MU005_FLED_FLASH_TIMEOUT, led->flash_timeout));
+ if (ret) {
+ dev_err(fled->led_cdev.dev, "failed to set flash timeout\n");
+ goto unlock;
+ }
+
+ ret = regmap_set_bits(led->regmap, led->reg_enable, S2MU005_FLED_FLASH_EN(led->channel));
+ if (ret) {
+ dev_err(fled->led_cdev.dev, "failed to enable flash LED\n");
+ goto unlock;
+ }
+
+unlock:
+ mutex_unlock(&led->lock);
+
+ return ret;
+}
+
+static int s2mu005_fled_flash_strobe_get(struct led_classdev_flash *fled, bool *state)
+{
+ struct s2m_led *led = to_s2m_led(fled);
+ u32 val;
+ int ret;
+
+ mutex_lock(&led->lock);
+
+ ret = regmap_read(led->regmap, S2MU005_REG_FLED_STATUS, &val);
+ if (ret) {
+ dev_err(fled->led_cdev.dev, "failed to fetch LED status\n");
+ goto unlock;
+ }
+
+ *state = !!(val & S2MU005_FLED_FLASH_STATUS(led->channel));
+
+unlock:
+ mutex_unlock(&led->lock);
+
+ return ret;
+}
+
+static const struct led_flash_ops s2mu005_fled_flash_ops = {
+ .flash_brightness_set = s2m_fled_flash_brightness_set,
+ .timeout_set = s2m_fled_flash_timeout_set,
+ .strobe_set = s2mu005_fled_flash_strobe_set,
+ .strobe_get = s2mu005_fled_flash_strobe_get,
+};
+
+static int s2mu005_fled_init(struct s2m_led *led, struct device *dev, struct regmap *regmap,
+ unsigned int nr_channels)
+{
+ unsigned int val;
+ int ret;
+
+ ret = regmap_read(regmap, S2MU005_REG_ID, &val);
+ if (ret)
+ return dev_err_probe(dev, ret, "failed to read revision\n");
+
+ for (int i = 0; i < nr_channels; i++) {
+ /*
+ * Read the revision register. Revision EVT0 has the register
+ * at CTRL4, while EVT1 and higher have it at CTRL6.
+ */
+ if (FIELD_GET(S2MU005_ID_MASK, val) == 0)
+ led[i].reg_enable = S2MU005_REG_FLED_CTRL4;
+ else
+ led[i].reg_enable = S2MU005_REG_FLED_CTRL6;
+ }
+
+ /* Enable the LED channels. */
+ ret = regmap_set_bits(regmap, S2MU005_REG_FLED_CTRL1, S2MU005_FLED_CH_EN);
+ if (ret)
+ return dev_err_probe(dev, ret, "failed to enable LED channels\n");
+
+ return 0;
+}
+
+static int s2mu005_fled_init_channel(struct s2m_led *led, struct device *dev,
+ struct fwnode_handle *fwnp)
+{
+ struct led_classdev *cdev = &led->fled.led_cdev;
+ struct led_init_data init_data = {};
+ struct v4l2_flash_config v4l2_cfg = {};
+ int ret;
+
+ cdev->max_brightness = 16;
+ cdev->brightness_set_blocking = s2mu005_fled_torch_brightness_set;
+ cdev->flags |= LED_DEV_CAP_FLASH;
+
+ led->fled.timeout.min = 62000;
+ led->fled.timeout.step = 62000;
+ led->fled.timeout.max = 992000;
+ led->fled.timeout.val = 992000;
+
+ led->fled.brightness.min = 25000;
+ led->fled.brightness.step = 25000;
+ led->fled.brightness.max = 375000; /* 400000 causes flickering */
+ led->fled.brightness.val = 375000;
+
+ s2m_fled_flash_timeout_set(&led->fled, led->fled.timeout.val);
+ s2m_fled_flash_brightness_set(&led->fled, led->fled.brightness.val);
+
+ led->fled.ops = &s2mu005_fled_flash_ops;
+
+ init_data.fwnode = fwnp;
+ ret = devm_led_classdev_flash_register_ext(dev, &led->fled, &init_data);
+ if (ret)
+ return dev_err_probe(dev, ret, "failed to create LED flash device\n");
+
+ v4l2_cfg.intensity.min = led->fled.brightness.min;
+ v4l2_cfg.intensity.step = led->fled.brightness.step;
+ v4l2_cfg.intensity.max = led->fled.brightness.max;
+ v4l2_cfg.intensity.val = led->fled.brightness.val;
+
+ v4l2_cfg.has_external_strobe = true;
+
+ led->v4l2_flash = v4l2_flash_init(dev, fwnp, &led->fled, &s2m_fled_v4l2_flash_ops,
+ &v4l2_cfg);
+ if (IS_ERR(led->v4l2_flash))
+ return dev_err_probe(dev, PTR_ERR(led->v4l2_flash),
+ "failed to create V4L2 flash device\n");
+
+ ret = devm_add_action_or_reset(dev, s2m_fled_v4l2_flash_release, led->v4l2_flash);
+ if (ret)
+ return dev_err_probe(dev, ret, "failed to add cleanup action\n");
+
+ return 0;
+}
+
+static int s2m_fled_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct sec_pmic_dev *ddata = dev_get_drvdata(dev->parent);
+ struct s2m_led *led;
+ int ret;
+
+ led = devm_kzalloc(dev, sizeof(*led) * MAX_CHANNELS, GFP_KERNEL);
+ if (!led)
+ return -ENOMEM;
+
+ /* Initialize LED controller with variant-specific implementation. */
+ ret = s2mu005_fled_init(led, dev, ddata->regmap_pmic, MAX_CHANNELS);
+ if (ret)
+ return ret;
+
+ device_for_each_child_node_scoped(dev, child) {
+ u32 reg;
+
+ if (fwnode_property_read_u32(child, "reg", ®))
+ continue;
+
+ if (reg >= MAX_CHANNELS) {
+ dev_warn(dev, "channel %d is non-existent\n", reg);
+ continue;
+ }
+
+ if (led[reg].regmap) {
+ dev_warn(dev, "duplicate node for channel %d\n", reg);
+ continue;
+ }
+
+ led[reg].regmap = ddata->regmap_pmic;
+ led[reg].channel = (u8)reg;
+
+ ret = devm_mutex_init(dev, &led[reg].lock);
+ if (ret)
+ return dev_err_probe(dev, ret, "failed to create mutex\n");
+
+ /* Initialize LED channel with variant-specific implementation. */
+ ret = s2mu005_fled_init_channel(led + reg, dev, child);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+static const struct platform_device_id s2m_fled_id_table[] = {
+ { "s2mu005-flash", S2MU005 },
+ { /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(platform, s2m_fled_id_table);
+
+static const struct of_device_id s2m_fled_of_match_table[] = {
+ { .compatible = "samsung,s2mu005-flash", .data = (void *)S2MU005 },
+ { /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, s2m_fled_of_match_table);
+
+static struct platform_driver s2m_fled_driver = {
+ .driver = {
+ .name = "s2m-flash",
+ },
+ .probe = s2m_fled_probe,
+ .id_table = s2m_fled_id_table,
+};
+module_platform_driver(s2m_fled_driver);
+
+MODULE_DESCRIPTION("Flash/Torch LED Driver for Samsung S2M Series PMICs");
+MODULE_AUTHOR("Kaustabh Chakraborty <kauschluss@disroot.org>");
+MODULE_LICENSE("GPL");
projects / thirdparty / kernel / linux.git / commitdiff
