--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2023 Richtek Technology Corp.
+ *
+ * Authors:
+ * Alice Chen <alice_chen@richtek.com>
+ * ChiYuan Huang <cy_huang@richtek.com>
+ */
+
+#include <linux/bitops.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/led-class-flash.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/platform_device.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+
+#include <media/v4l2-flash-led-class.h>
+
+enum {
+ MT6370_LED_FLASH1 = 0,
+ MT6370_LED_FLASH2,
+ MT6370_MAX_LEDS
+};
+
+/* Virtual definition for multicolor */
+
+#define MT6370_REG_FLEDEN 0x17E
+#define MT6370_REG_STRBTO 0x173
+#define MT6370_REG_CHGSTAT2 0x1D1
+#define MT6370_REG_FLEDSTAT1 0x1D9
+#define MT6370_REG_FLEDISTRB(_id) (0x174 + 4 * (_id))
+#define MT6370_REG_FLEDITOR(_id) (0x175 + 4 * (_id))
+#define MT6370_ITORCH_MASK GENMASK(4, 0)
+#define MT6370_ISTROBE_MASK GENMASK(6, 0)
+#define MT6370_STRBTO_MASK GENMASK(6, 0)
+#define MT6370_TORCHEN_MASK BIT(3)
+#define MT6370_STROBEN_MASK BIT(2)
+#define MT6370_FLCSEN_MASK(_id) BIT(MT6370_LED_FLASH2 - (_id))
+#define MT6370_FLCSEN_MASK_ALL GENMASK(1, 0)
+#define MT6370_FLEDCHGVINOVP_MASK BIT(3)
+#define MT6370_FLED1STRBTO_MASK BIT(11)
+#define MT6370_FLED2STRBTO_MASK BIT(10)
+#define MT6370_FLED1STRB_MASK BIT(9)
+#define MT6370_FLED2STRB_MASK BIT(8)
+#define MT6370_FLED1SHORT_MASK BIT(7)
+#define MT6370_FLED2SHORT_MASK BIT(6)
+#define MT6370_FLEDLVF_MASK BIT(3)
+
+#define MT6370_LED_JOINT 2
+#define MT6370_RANGE_FLED_REG 4
+#define MT6370_ITORCH_MIN_uA 25000
+#define MT6370_ITORCH_STEP_uA 12500
+#define MT6370_ITORCH_MAX_uA 400000
+#define MT6370_ITORCH_DOUBLE_MAX_uA 800000
+#define MT6370_ISTRB_MIN_uA 50000
+#define MT6370_ISTRB_STEP_uA 12500
+#define MT6370_ISTRB_MAX_uA 1500000
+#define MT6370_ISTRB_DOUBLE_MAX_uA 3000000
+#define MT6370_STRBTO_MIN_US 64000
+#define MT6370_STRBTO_STEP_US 32000
+#define MT6370_STRBTO_MAX_US 2432000
+
+#define to_mt6370_led(ptr, member) container_of(ptr, struct mt6370_led, member)
+
+struct mt6370_led {
+ struct led_classdev_flash flash;
+ struct v4l2_flash *v4l2_flash;
+ struct mt6370_priv *priv;
+ u8 led_no;
+};
+
+struct mt6370_priv {
+ struct regmap *regmap;
+ struct mutex lock;
+ unsigned int fled_strobe_used;
+ unsigned int fled_torch_used;
+ unsigned int leds_active;
+ unsigned int leds_count;
+ struct mt6370_led leds[];
+};
+
+static int mt6370_torch_brightness_set(struct led_classdev *lcdev, enum led_brightness level)
+{
+ struct mt6370_led *led = to_mt6370_led(lcdev, flash.led_cdev);
+ struct mt6370_priv *priv = led->priv;
+ u32 led_enable_mask = led->led_no == MT6370_LED_JOINT ? MT6370_FLCSEN_MASK_ALL :
+ MT6370_FLCSEN_MASK(led->led_no);
+ u32 enable_mask = MT6370_TORCHEN_MASK | led_enable_mask;
+ u32 val = level ? led_enable_mask : 0;
+ u32 curr;
+ int ret, i;
+
+ mutex_lock(&priv->lock);
+
+ /*
+ * There is only one set of flash control logic, and this flag is used to check if 'strobe'
+ * is currently being used.
+ */
+ if (priv->fled_strobe_used) {
+ dev_warn(lcdev->dev, "Please disable strobe first [%d]\n", priv->fled_strobe_used);
+ ret = -EBUSY;
+ goto unlock;
+ }
+
+ if (level)
+ curr = priv->fled_torch_used | BIT(led->led_no);
+ else
+ curr = priv->fled_torch_used & ~BIT(led->led_no);
+
+ if (curr)
+ val |= MT6370_TORCHEN_MASK;
+
+ if (level) {
+ level -= 1;
+ if (led->led_no == MT6370_LED_JOINT) {
+ u32 flevel[MT6370_MAX_LEDS];
+
+ /*
+ * There're two flash channels in MT6370. If joint flash output is used,
+ * torch current will be averaged output from both channels.
+ */
+ flevel[0] = level / 2;
+ flevel[1] = level - flevel[0];
+ for (i = 0; i < MT6370_MAX_LEDS; i++) {
+ ret = regmap_update_bits(priv->regmap, MT6370_REG_FLEDITOR(i),
+ MT6370_ITORCH_MASK, flevel[i]);
+ if (ret)
+ goto unlock;
+ }
+ } else {
+ ret = regmap_update_bits(priv->regmap, MT6370_REG_FLEDITOR(led->led_no),
+ MT6370_ITORCH_MASK, level);
+ if (ret)
+ goto unlock;
+ }
+ }
+
+ ret = regmap_update_bits(priv->regmap, MT6370_REG_FLEDEN, enable_mask, val);
+ if (ret)
+ goto unlock;
+
+ priv->fled_torch_used = curr;
+
+unlock:
+ mutex_unlock(&priv->lock);
+ return ret;
+}
+
+static int mt6370_flash_brightness_set(struct led_classdev_flash *fl_cdev, u32 brightness)
+{
+ /*
+ * Because of the current spikes when turning on the flash, the brightness should be kept
+ * by the LED framework. This empty function is used to prevent checking failure when
+ * led_classdev_flash registers ops.
+ */
+ return 0;
+}
+
+static int _mt6370_flash_brightness_set(struct led_classdev_flash *fl_cdev, u32 brightness)
+{
+ struct mt6370_led *led = to_mt6370_led(fl_cdev, flash);
+ struct mt6370_priv *priv = led->priv;
+ struct led_flash_setting *setting = &fl_cdev->brightness;
+ u32 val = (brightness - setting->min) / setting->step;
+ int ret, i;
+
+ if (led->led_no == MT6370_LED_JOINT) {
+ u32 flevel[MT6370_MAX_LEDS];
+
+ /*
+ * There're two flash channels in MT6370. If joint flash output is used, storbe
+ * current will be averaged output from both channels.
+ */
+ flevel[0] = val / 2;
+ flevel[1] = val - flevel[0];
+ for (i = 0; i < MT6370_MAX_LEDS; i++) {
+ ret = regmap_update_bits(priv->regmap, MT6370_REG_FLEDISTRB(i),
+ MT6370_ISTROBE_MASK, flevel[i]);
+ if (ret)
+ break;
+ }
+ } else {
+ ret = regmap_update_bits(priv->regmap, MT6370_REG_FLEDISTRB(led->led_no),
+ MT6370_ISTROBE_MASK, val);
+ }
+
+ return ret;
+}
+
+static int mt6370_strobe_set(struct led_classdev_flash *fl_cdev, bool state)
+{
+ struct mt6370_led *led = to_mt6370_led(fl_cdev, flash);
+ struct mt6370_priv *priv = led->priv;
+ struct led_classdev *lcdev = &fl_cdev->led_cdev;
+ struct led_flash_setting *s = &fl_cdev->brightness;
+ u32 led_enable_mask = led->led_no == MT6370_LED_JOINT ? MT6370_FLCSEN_MASK_ALL :
+ MT6370_FLCSEN_MASK(led->led_no);
+ u32 enable_mask = MT6370_STROBEN_MASK | led_enable_mask;
+ u32 val = state ? led_enable_mask : 0;
+ u32 curr;
+ int ret;
+
+ mutex_lock(&priv->lock);
+
+ /*
+ * There is only one set of flash control logic, and this flag is used to check if 'torch'
+ * is currently being used.
+ */
+ if (priv->fled_torch_used) {
+ dev_warn(lcdev->dev, "Please disable torch first [0x%x]\n", priv->fled_torch_used);
+ ret = -EBUSY;
+ goto unlock;
+ }
+
+ if (state)
+ curr = priv->fled_strobe_used | BIT(led->led_no);
+ else
+ curr = priv->fled_strobe_used & ~BIT(led->led_no);
+
+ if (curr)
+ val |= MT6370_STROBEN_MASK;
+
+ ret = regmap_update_bits(priv->regmap, MT6370_REG_FLEDEN, enable_mask, val);
+ if (ret) {
+ dev_err(lcdev->dev, "[%d] control current source %d fail\n", led->led_no, state);
+ goto unlock;
+ }
+
+ /*
+ * If the flash needs to turn on, configure the flash current to ramp up to the setting
+ * value. Otherwise, always revert to the minimum one.
+ */
+ ret = _mt6370_flash_brightness_set(fl_cdev, state ? s->val : s->min);
+ if (ret) {
+ dev_err(lcdev->dev, "[%d] Failed to set brightness\n", led->led_no);
+ goto unlock;
+ }
+
+ /*
+ * For the flash to turn on/off, we must wait for HW ramping up/down time 5ms/500us to
+ * prevent the unexpected problem.
+ */
+ if (!priv->fled_strobe_used && curr)
+ usleep_range(5000, 6000);
+ else if (priv->fled_strobe_used && !curr)
+ usleep_range(500, 600);
+
+ priv->fled_strobe_used = curr;
+
+unlock:
+ mutex_unlock(&priv->lock);
+ return ret;
+}
+
+static int mt6370_strobe_get(struct led_classdev_flash *fl_cdev, bool *state)
+{
+ struct mt6370_led *led = to_mt6370_led(fl_cdev, flash);
+ struct mt6370_priv *priv = led->priv;
+
+ mutex_lock(&priv->lock);
+ *state = !!(priv->fled_strobe_used & BIT(led->led_no));
+ mutex_unlock(&priv->lock);
+
+ return 0;
+}
+
+static int mt6370_timeout_set(struct led_classdev_flash *fl_cdev, u32 timeout)
+{
+ struct mt6370_led *led = to_mt6370_led(fl_cdev, flash);
+ struct mt6370_priv *priv = led->priv;
+ struct led_flash_setting *s = &fl_cdev->timeout;
+ u32 val = (timeout - s->min) / s->step;
+
+ return regmap_update_bits(priv->regmap, MT6370_REG_STRBTO, MT6370_STRBTO_MASK, val);
+}
+
+static int mt6370_fault_get(struct led_classdev_flash *fl_cdev, u32 *fault)
+{
+ struct mt6370_led *led = to_mt6370_led(fl_cdev, flash);
+ struct mt6370_priv *priv = led->priv;
+ u16 fled_stat;
+ unsigned int chg_stat, strobe_timeout_mask, fled_short_mask;
+ u32 rfault = 0;
+ int ret;
+
+ ret = regmap_read(priv->regmap, MT6370_REG_CHGSTAT2, &chg_stat);
+ if (ret)
+ return ret;
+
+ ret = regmap_raw_read(priv->regmap, MT6370_REG_FLEDSTAT1, &fled_stat, sizeof(fled_stat));
+ if (ret)
+ return ret;
+
+ switch (led->led_no) {
+ case MT6370_LED_FLASH1:
+ strobe_timeout_mask = MT6370_FLED1STRBTO_MASK;
+ fled_short_mask = MT6370_FLED1SHORT_MASK;
+ break;
+
+ case MT6370_LED_FLASH2:
+ strobe_timeout_mask = MT6370_FLED2STRBTO_MASK;
+ fled_short_mask = MT6370_FLED2SHORT_MASK;
+ break;
+
+ case MT6370_LED_JOINT:
+ strobe_timeout_mask = MT6370_FLED1STRBTO_MASK | MT6370_FLED2STRBTO_MASK;
+ fled_short_mask = MT6370_FLED1SHORT_MASK | MT6370_FLED2SHORT_MASK;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ if (chg_stat & MT6370_FLEDCHGVINOVP_MASK)
+ rfault |= LED_FAULT_INPUT_VOLTAGE;
+
+ if (fled_stat & strobe_timeout_mask)
+ rfault |= LED_FAULT_TIMEOUT;
+
+ if (fled_stat & fled_short_mask)
+ rfault |= LED_FAULT_SHORT_CIRCUIT;
+
+ if (fled_stat & MT6370_FLEDLVF_MASK)
+ rfault |= LED_FAULT_UNDER_VOLTAGE;
+
+ *fault = rfault;
+ return ret;
+}
+
+static const struct led_flash_ops mt6370_flash_ops = {
+ .flash_brightness_set = mt6370_flash_brightness_set,
+ .strobe_set = mt6370_strobe_set,
+ .strobe_get = mt6370_strobe_get,
+ .timeout_set = mt6370_timeout_set,
+ .fault_get = mt6370_fault_get,
+};
+
+#if IS_ENABLED(CONFIG_V4L2_FLASH_LED_CLASS)
+static int mt6370_flash_external_strobe_set(struct v4l2_flash *v4l2_flash,
+ bool enable)
+{
+ struct led_classdev_flash *flash = v4l2_flash->fled_cdev;
+ struct mt6370_led *led = to_mt6370_led(flash, flash);
+ struct mt6370_priv *priv = led->priv;
+ u32 mask = led->led_no == MT6370_LED_JOINT ? MT6370_FLCSEN_MASK_ALL :
+ MT6370_FLCSEN_MASK(led->led_no);
+ u32 val = enable ? mask : 0;
+ int ret;
+
+ mutex_lock(&priv->lock);
+
+ ret = regmap_update_bits(priv->regmap, MT6370_REG_FLEDEN, mask, val);
+ if (ret)
+ goto unlock;
+
+ if (enable)
+ priv->fled_strobe_used |= BIT(led->led_no);
+ else
+ priv->fled_strobe_used &= ~BIT(led->led_no);
+
+unlock:
+ mutex_unlock(&priv->lock);
+ return ret;
+}
+
+static const struct v4l2_flash_ops v4l2_flash_ops = {
+ .external_strobe_set = mt6370_flash_external_strobe_set,
+};
+
+static void mt6370_init_v4l2_flash_config(struct mt6370_led *led, struct v4l2_flash_config *cfg)
+{
+ struct led_classdev *lcdev;
+ struct led_flash_setting *s = &cfg->intensity;
+
+ lcdev = &led->flash.led_cdev;
+
+ s->min = MT6370_ITORCH_MIN_uA;
+ s->step = MT6370_ITORCH_STEP_uA;
+ s->val = s->max = s->min + (lcdev->max_brightness - 1) * s->step;
+
+ cfg->has_external_strobe = 1;
+ strscpy(cfg->dev_name, dev_name(lcdev->dev), sizeof(cfg->dev_name));
+
+ cfg->flash_faults = LED_FAULT_SHORT_CIRCUIT | LED_FAULT_TIMEOUT |
+ LED_FAULT_INPUT_VOLTAGE | LED_FAULT_UNDER_VOLTAGE;
+}
+#else
+static const struct v4l2_flash_ops v4l2_flash_ops;
+static void mt6370_init_v4l2_flash_config(struct mt6370_led *led, struct v4l2_flash_config *cfg)
+{
+}
+#endif
+
+static void mt6370_v4l2_flash_release(void *v4l2_flash)
+{
+ v4l2_flash_release(v4l2_flash);
+}
+
+static int mt6370_led_register(struct device *parent, struct mt6370_led *led,
+ struct fwnode_handle *fwnode)
+{
+ struct led_init_data init_data = { .fwnode = fwnode };
+ struct v4l2_flash_config v4l2_config = {};
+ int ret;
+
+ ret = devm_led_classdev_flash_register_ext(parent, &led->flash, &init_data);
+ if (ret)
+ return dev_err_probe(parent, ret, "Couldn't register flash %d\n", led->led_no);
+
+ mt6370_init_v4l2_flash_config(led, &v4l2_config);
+ led->v4l2_flash = v4l2_flash_init(parent, fwnode, &led->flash, &v4l2_flash_ops,
+ &v4l2_config);
+ if (IS_ERR(led->v4l2_flash))
+ return dev_err_probe(parent, PTR_ERR(led->v4l2_flash),
+ "Failed to register %d v4l2 sd\n", led->led_no);
+
+ return devm_add_action_or_reset(parent, mt6370_v4l2_flash_release, led->v4l2_flash);
+}
+
+static u32 mt6370_clamp(u32 val, u32 min, u32 max, u32 step)
+{
+ u32 retval;
+
+ retval = clamp_val(val, min, max);
+ if (step > 1)
+ retval = rounddown(retval - min, step) + min;
+
+ return retval;
+}
+
+static int mt6370_init_flash_properties(struct device *dev, struct mt6370_led *led,
+ struct fwnode_handle *fwnode)
+{
+ struct led_classdev_flash *flash = &led->flash;
+ struct led_classdev *lcdev = &flash->led_cdev;
+ struct mt6370_priv *priv = led->priv;
+ struct led_flash_setting *s;
+ u32 sources[MT6370_MAX_LEDS];
+ u32 max_ua, val;
+ int i, ret, num;
+
+ num = fwnode_property_count_u32(fwnode, "led-sources");
+ if (num < 1)
+ return dev_err_probe(dev, -EINVAL,
+ "Not specified or wrong number of led-sources\n");
+
+ ret = fwnode_property_read_u32_array(fwnode, "led-sources", sources, num);
+ if (ret)
+ return ret;
+
+ for (i = 0; i < num; i++) {
+ if (sources[i] >= MT6370_MAX_LEDS)
+ return -EINVAL;
+ if (priv->leds_active & BIT(sources[i]))
+ return -EINVAL;
+ priv->leds_active |= BIT(sources[i]);
+ }
+
+ /* If both channels are specified in 'led-sources', joint flash output mode is used */
+ led->led_no = num == 2 ? MT6370_LED_JOINT : sources[0];
+
+ max_ua = num == 2 ? MT6370_ITORCH_DOUBLE_MAX_uA : MT6370_ITORCH_MAX_uA;
+ val = MT6370_ITORCH_MIN_uA;
+ ret = fwnode_property_read_u32(fwnode, "led-max-microamp", &val);
+ if (!ret)
+ val = mt6370_clamp(val, MT6370_ITORCH_MIN_uA, max_ua, MT6370_ITORCH_STEP_uA);
+
+ lcdev->max_brightness = (val - MT6370_ITORCH_MIN_uA) / MT6370_ITORCH_STEP_uA + 1;
+ lcdev->brightness_set_blocking = mt6370_torch_brightness_set;
+ lcdev->flags |= LED_DEV_CAP_FLASH;
+
+ max_ua = num == 2 ? MT6370_ISTRB_DOUBLE_MAX_uA : MT6370_ISTRB_MAX_uA;
+ val = MT6370_ISTRB_MIN_uA;
+ ret = fwnode_property_read_u32(fwnode, "flash-max-microamp", &val);
+ if (!ret)
+ val = mt6370_clamp(val, MT6370_ISTRB_MIN_uA, max_ua, MT6370_ISTRB_STEP_uA);
+
+ s = &flash->brightness;
+ s->min = MT6370_ISTRB_MIN_uA;
+ s->step = MT6370_ISTRB_STEP_uA;
+ s->val = s->max = val;
+
+ /* Always configure to the minimum level when off to prevent flash current spikes. */
+ ret = _mt6370_flash_brightness_set(flash, s->min);
+ if (ret)
+ return ret;
+
+ val = MT6370_STRBTO_MIN_US;
+ ret = fwnode_property_read_u32(fwnode, "flash-max-timeout-us", &val);
+ if (!ret)
+ val = mt6370_clamp(val, MT6370_STRBTO_MIN_US, MT6370_STRBTO_MAX_US,
+ MT6370_STRBTO_STEP_US);
+
+ s = &flash->timeout;
+ s->min = MT6370_STRBTO_MIN_US;
+ s->step = MT6370_STRBTO_STEP_US;
+ s->val = s->max = val;
+
+ flash->ops = &mt6370_flash_ops;
+
+ return 0;
+}
+
+static int mt6370_led_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct mt6370_priv *priv;
+ struct fwnode_handle *child;
+ size_t count;
+ int i = 0, ret;
+
+ count = device_get_child_node_count(dev);
+ if (!count || count > MT6370_MAX_LEDS)
+ return dev_err_probe(dev, -EINVAL,
+ "No child node or node count over max led number %zu\n", count);
+
+ priv = devm_kzalloc(dev, struct_size(priv, leds, count), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->leds_count = count;
+ mutex_init(&priv->lock);
+
+ priv->regmap = dev_get_regmap(dev->parent, NULL);
+ if (!priv->regmap)
+ return dev_err_probe(dev, -ENODEV, "Failed to get parent regmap\n");
+
+ device_for_each_child_node(dev, child) {
+ struct mt6370_led *led = priv->leds + i;
+
+ led->priv = priv;
+
+ ret = mt6370_init_flash_properties(dev, led, child);
+ if (ret) {
+ fwnode_handle_put(child);
+ return ret;
+ }
+
+ ret = mt6370_led_register(dev, led, child);
+ if (ret) {
+ fwnode_handle_put(child);
+ return ret;
+ }
+
+ i++;
+ }
+
+ return 0;
+}
+
+static const struct of_device_id mt6370_led_of_id[] = {
+ { .compatible = "mediatek,mt6370-flashlight" },
+ {}
+};
+MODULE_DEVICE_TABLE(of, mt6370_led_of_id);
+
+static struct platform_driver mt6370_led_driver = {
+ .driver = {
+ .name = "mt6370-flashlight",
+ .of_match_table = mt6370_led_of_id,
+ },
+ .probe = mt6370_led_probe,
+};
+module_platform_driver(mt6370_led_driver);
+
+MODULE_AUTHOR("Alice Chen <alice_chen@richtek.com>");
+MODULE_AUTHOR("ChiYuan Huang <cy_huang@richtek.com>");
+MODULE_DESCRIPTION("MT6370 FLASH LED Driver");
+MODULE_LICENSE("GPL");
projects / linux-2.6-microblaze.git / commitdiff