diff --git a/Documentation/ABI/testing/sysfs-class-led-driver-sc27xx b/Documentation/ABI/testing/sysfs-class-led-driver-sc27xx new file mode 100644 index 000000000000..45b1e605d355 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-class-led-driver-sc27xx @@ -0,0 +1,22 @@ +What: /sys/class/leds//hw_pattern +Date: September 2018 +KernelVersion: 4.20 +Description: + Specify a hardware pattern for the SC27XX LED. For the SC27XX + LED controller, it only supports 4 stages to make a single + hardware pattern, which is used to configure the rise time, + high time, fall time and low time for the breathing mode. + + For the breathing mode, the SC27XX LED only expects one brightness + for the high stage. To be compatible with the hardware pattern + format, we should set brightness as 0 for rise stage, fall + stage and low stage. + + Min stage duration: 125 ms + Max stage duration: 31875 ms + + Since the stage duration step is 125 ms, the duration should be + a multiplier of 125, like 125ms, 250ms, 375ms, 500ms ... 31875ms. + + Thus the format of the hardware pattern values should be: + "0 rise_duration brightness high_duration 0 fall_duration 0 low_duration". diff --git a/drivers/leds/leds-sc27xx-bltc.c b/drivers/leds/leds-sc27xx-bltc.c index 9d9b7aab843f..fecf27fb1cdc 100644 --- a/drivers/leds/leds-sc27xx-bltc.c +++ b/drivers/leds/leds-sc27xx-bltc.c @@ -32,8 +32,18 @@ #define SC27XX_DUTY_MASK GENMASK(15, 0) #define SC27XX_MOD_MASK GENMASK(7, 0) +#define SC27XX_CURVE_SHIFT 8 +#define SC27XX_CURVE_L_MASK GENMASK(7, 0) +#define SC27XX_CURVE_H_MASK GENMASK(15, 8) + #define SC27XX_LEDS_OFFSET 0x10 #define SC27XX_LEDS_MAX 3 +#define SC27XX_LEDS_PATTERN_CNT 4 +/* Stage duration step, in milliseconds */ +#define SC27XX_LEDS_STEP 125 +/* Minimum and maximum duration, in milliseconds */ +#define SC27XX_DELTA_T_MIN SC27XX_LEDS_STEP +#define SC27XX_DELTA_T_MAX (SC27XX_LEDS_STEP * 255) struct sc27xx_led { char name[LED_MAX_NAME_SIZE]; @@ -122,6 +132,113 @@ static int sc27xx_led_set(struct led_classdev *ldev, enum led_brightness value) return err; } +static void sc27xx_led_clamp_align_delta_t(u32 *delta_t) +{ + u32 v, offset, t = *delta_t; + + v = t + SC27XX_LEDS_STEP / 2; + v = clamp_t(u32, v, SC27XX_DELTA_T_MIN, SC27XX_DELTA_T_MAX); + offset = v - SC27XX_DELTA_T_MIN; + offset = SC27XX_LEDS_STEP * (offset / SC27XX_LEDS_STEP); + + *delta_t = SC27XX_DELTA_T_MIN + offset; +} + +static int sc27xx_led_pattern_clear(struct led_classdev *ldev) +{ + struct sc27xx_led *leds = to_sc27xx_led(ldev); + struct regmap *regmap = leds->priv->regmap; + u32 base = sc27xx_led_get_offset(leds); + u32 ctrl_base = leds->priv->base + SC27XX_LEDS_CTRL; + u8 ctrl_shift = SC27XX_CTRL_SHIFT * leds->line; + int err; + + mutex_lock(&leds->priv->lock); + + /* Reset the rise, high, fall and low time to zero. */ + regmap_write(regmap, base + SC27XX_LEDS_CURVE0, 0); + regmap_write(regmap, base + SC27XX_LEDS_CURVE1, 0); + + err = regmap_update_bits(regmap, ctrl_base, + (SC27XX_LED_RUN | SC27XX_LED_TYPE) << ctrl_shift, 0); + + ldev->brightness = LED_OFF; + + mutex_unlock(&leds->priv->lock); + + return err; +} + +static int sc27xx_led_pattern_set(struct led_classdev *ldev, + struct led_pattern *pattern, + u32 len, int repeat) +{ + struct sc27xx_led *leds = to_sc27xx_led(ldev); + u32 base = sc27xx_led_get_offset(leds); + u32 ctrl_base = leds->priv->base + SC27XX_LEDS_CTRL; + u8 ctrl_shift = SC27XX_CTRL_SHIFT * leds->line; + struct regmap *regmap = leds->priv->regmap; + int err; + + /* + * Must contain 4 tuples to configure the rise time, high time, fall + * time and low time to enable the breathing mode. + */ + if (len != SC27XX_LEDS_PATTERN_CNT) + return -EINVAL; + + mutex_lock(&leds->priv->lock); + + sc27xx_led_clamp_align_delta_t(&pattern[0].delta_t); + err = regmap_update_bits(regmap, base + SC27XX_LEDS_CURVE0, + SC27XX_CURVE_L_MASK, + pattern[0].delta_t / SC27XX_LEDS_STEP); + if (err) + goto out; + + sc27xx_led_clamp_align_delta_t(&pattern[1].delta_t); + err = regmap_update_bits(regmap, base + SC27XX_LEDS_CURVE1, + SC27XX_CURVE_L_MASK, + pattern[1].delta_t / SC27XX_LEDS_STEP); + if (err) + goto out; + + sc27xx_led_clamp_align_delta_t(&pattern[2].delta_t); + err = regmap_update_bits(regmap, base + SC27XX_LEDS_CURVE0, + SC27XX_CURVE_H_MASK, + (pattern[2].delta_t / SC27XX_LEDS_STEP) << + SC27XX_CURVE_SHIFT); + if (err) + goto out; + + sc27xx_led_clamp_align_delta_t(&pattern[3].delta_t); + err = regmap_update_bits(regmap, base + SC27XX_LEDS_CURVE1, + SC27XX_CURVE_H_MASK, + (pattern[3].delta_t / SC27XX_LEDS_STEP) << + SC27XX_CURVE_SHIFT); + if (err) + goto out; + + err = regmap_update_bits(regmap, base + SC27XX_LEDS_DUTY, + SC27XX_DUTY_MASK, + (pattern[1].brightness << SC27XX_DUTY_SHIFT) | + SC27XX_MOD_MASK); + if (err) + goto out; + + /* Enable the LED breathing mode */ + err = regmap_update_bits(regmap, ctrl_base, + SC27XX_LED_RUN << ctrl_shift, + SC27XX_LED_RUN << ctrl_shift); + if (!err) + ldev->brightness = pattern[1].brightness; + +out: + mutex_unlock(&leds->priv->lock); + + return err; +} + static int sc27xx_led_register(struct device *dev, struct sc27xx_led_priv *priv) { int i, err; @@ -140,6 +257,9 @@ static int sc27xx_led_register(struct device *dev, struct sc27xx_led_priv *priv) led->priv = priv; led->ldev.name = led->name; led->ldev.brightness_set_blocking = sc27xx_led_set; + led->ldev.pattern_set = sc27xx_led_pattern_set; + led->ldev.pattern_clear = sc27xx_led_pattern_clear; + led->ldev.default_trigger = "pattern"; err = devm_led_classdev_register(dev, &led->ldev); if (err) @@ -241,4 +361,5 @@ module_platform_driver(sc27xx_led_driver); MODULE_DESCRIPTION("Spreadtrum SC27xx breathing light controller driver"); MODULE_AUTHOR("Xiaotong Lu "); +MODULE_AUTHOR("Baolin Wang "); MODULE_LICENSE("GPL v2");