Merge branch 'for-next/pwm'

1 files changed, 90 insertions, 0 deletions

diff --git a/drivers/video/backlight.c b/drivers/video/backlight.c
new file mode 100644
index 0000000000..ddde6f8523
--- /dev/null
+++ b/drivers/video/backlight.c
@@ -0,0 +1,90 @@
+#include <common.h>
+#include <driver.h>
+#include <linux/list.h>
+#include <video/backlight.h>
+
+static LIST_HEAD(backlights);
+
+int backlight_set_brightness(struct backlight_device *bl, int brightness)
+{
+	int ret, step, i, num_steps;
+
+	if (brightness > bl->brightness_max)
+		brightness = bl->brightness_max;
+
+	if (brightness == bl->brightness_cur)
+		return 0;
+
+	if (brightness > bl->brightness_cur)
+		step = 1;
+	else
+		step = -1;
+
+	i = bl->brightness_cur;
+
+	num_steps = abs(brightness - bl->brightness_cur);
+
+	while (1) {
+		i += step;
+
+		ret = bl->brightness_set(bl, i);
+		if (ret)
+			return ret;
+
+		if (i == brightness)
+			break;
+
+		udelay(100000 / num_steps);
+	}
+
+
+	bl->brightness_cur = bl->brightness = brightness;
+
+	return ret;
+}
+
+int backlight_set_brightness_default(struct backlight_device *bl)
+{
+	int ret;
+
+	ret = backlight_set_brightness(bl, bl->brightness_default);
+
+	return ret;
+}
+
+static int backlight_brightness_set(struct param_d *p, void *priv)
+{
+	struct backlight_device *bl = priv;
+
+	return backlight_set_brightness(bl, bl->brightness);
+}
+
+int backlight_register(struct backlight_device *bl)
+{
+	int ret;
+
+	sprintf(bl->dev.name, "backlight");
+	bl->dev.id = DEVICE_ID_DYNAMIC;
+
+	ret = register_device(&bl->dev);
+	if (ret)
+		return ret;
+
+	dev_add_param_int(&bl->dev, "brightness", backlight_brightness_set,
+			NULL, &bl->brightness, "%d", bl);
+
+	list_add_tail(&bl->list, &backlights);
+
+	return ret;
+}
+
+struct backlight_device *of_backlight_find(struct device_node *node)
+{
+	struct backlight_device *bl;
+
+	list_for_each_entry(bl, &backlights, list)
+		if (bl->node == node)
+			return bl;
+
+	return NULL;
+}