// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2023 Richtek Technology Corp.
*
* Authors:
* Alice Chen <[email protected]>
* ChiYuan Huang <[email protected]>
*/
#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[] __counted_by(leds_count);
};
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 <[email protected]>");
MODULE_AUTHOR("ChiYuan Huang <[email protected]>");
MODULE_DESCRIPTION("MT6370 FLASH LED Driver");
MODULE_LICENSE("GPL");
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