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 <paul.henrys_ext@softathome.com>

diff --git a/drivers/led/led_bcm6858.c b/drivers/led/led_bcm6858.c
index fbf46a114c522db5b60f2c14ca52f71a818631ef..3ca6c5b8a9e299b329dd313a35dd8c2cac6ffd50 100644 (file)
--- 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;