From 877de2a369aaeebe7fb0a2f8f1438255d249c6c0 Mon Sep 17 00:00:00 2001 From: Paul HENRYS Date: Thu, 17 Mar 2022 10:29:47 +0100 Subject: drivers: led: bcm6858: Set a default brightness when probing LEDs When probing the LEDs, a default brightness is set based on settings from the U-Boot device tree, i.e. the 'default-brightness' property of the LED nodes. If that property is not present, the default maximum brightness is set. This should make sure the LED controller's registers affecting the brightness are correctly initialized and should give a consistent behaviour. Signed-off-by: Paul HENRYS --- drivers/led/led_bcm6858.c | 32 +++++++++++++++++++++++++++++++- 1 file changed, 31 insertions(+), 1 deletion(-) diff --git a/drivers/led/led_bcm6858.c b/drivers/led/led_bcm6858.c index fbf46a1..3ca6c5b 100644 --- a/drivers/led/led_bcm6858.c +++ b/drivers/led/led_bcm6858.c @@ -18,6 +18,7 @@ #define LEDS_MAX 32 #define LEDS_WAIT 100 +#define LEDS_MAX_BRIGHTNESS 7 /* LED Mode register */ #define LED_MODE_REG 0x0 @@ -38,6 +39,8 @@ #define LED_HW_LED_EN_REG 0x08 /* LED Flash control register0 */ #define LED_FLASH_RATE_CONTROL_REG0 0x10 +/* LED Brightness control register0 */ +#define LED_BRIGHTNESS_CONTROL_REG0 0x20 /* Soft LED input register */ #define LED_SW_LED_IP_REG 0xb8 /* Parallel LED Output Polarity Register */ @@ -96,6 +99,27 @@ static int bcm6858_led_set_period(struct udevice *dev, int period_ms) } #endif +static int led_set_brightness(struct udevice *dev, unsigned int brightness) +{ + struct bcm6858_led_priv *priv = dev_get_priv(dev); + u32 offset, shift, mask, value; + + offset = (priv->pin / 8) * 4; + shift = (priv->pin % 8) * 4; + mask = 0xf << shift; + + /* 8 levels of brightness achieved through PWM */ + value = (brightness > LEDS_MAX_BRIGHTNESS ? + LEDS_MAX_BRIGHTNESS : brightness) << shift; + + debug("%s: %s brightness set to %u\n", __func__, dev->name, value >> shift); + + clrbits_32(priv->regs + LED_BRIGHTNESS_CONTROL_REG0 + offset, mask); + setbits_32(priv->regs + LED_BRIGHTNESS_CONTROL_REG0 + offset, value); + + return 0; +} + static enum led_state_t bcm6858_led_get_state(struct udevice *dev) { struct bcm6858_led_priv *priv = dev_get_priv(dev); @@ -113,6 +137,8 @@ static int bcm6858_led_set_state(struct udevice *dev, enum led_state_t state) { struct bcm6858_led_priv *priv = dev_get_priv(dev); + debug("%s: Set led %s to %d\n", __func__, dev->name, state); + switch (state) { case LEDST_OFF: clrbits_32(priv->regs + LED_SW_LED_IP_REG, (1 << priv->pin)); @@ -180,7 +206,7 @@ static int bcm6858_led_probe(struct udevice *dev) } else { struct bcm6858_led_priv *priv = dev_get_priv(dev); void __iomem *regs; - unsigned int pin; + unsigned int pin, brightness; regs = dev_remap_addr(dev_get_parent(dev)); if (!regs) @@ -201,6 +227,10 @@ static int bcm6858_led_probe(struct udevice *dev) clrbits_32(regs + LED_PLED_OP_PPOL_REG, 1 << pin); else setbits_32(regs + LED_PLED_OP_PPOL_REG, 1 << pin); + + brightness = dev_read_u32_default(dev, "default-brightness", + LEDS_MAX_BRIGHTNESS); + led_set_brightness(dev, brightness); } return 0; -- cgit v1.1