diff options
Diffstat (limited to 'drivers/video/backlight/rt4831-backlight.c')
| -rw-r--r-- | drivers/video/backlight/rt4831-backlight.c | 39 |
1 files changed, 35 insertions, 4 deletions
diff --git a/drivers/video/backlight/rt4831-backlight.c b/drivers/video/backlight/rt4831-backlight.c index 42155c7d2db1..26214519bfce 100644 --- a/drivers/video/backlight/rt4831-backlight.c +++ b/drivers/video/backlight/rt4831-backlight.c @@ -4,6 +4,7 @@ #include <linux/backlight.h> #include <linux/bitops.h> #include <linux/kernel.h> +#include <linux/mod_devicetable.h> #include <linux/module.h> #include <linux/platform_device.h> #include <linux/property.h> @@ -12,6 +13,7 @@ #define RT4831_REG_BLCFG 0x02 #define RT4831_REG_BLDIML 0x04 #define RT4831_REG_ENABLE 0x08 +#define RT4831_REG_BLOPT2 0x11 #define RT4831_BLMAX_BRIGHTNESS 2048 @@ -23,6 +25,11 @@ #define RT4831_BLDIML_MASK GENMASK(2, 0) #define RT4831_BLDIMH_MASK GENMASK(10, 3) #define RT4831_BLDIMH_SHIFT 3 +#define RT4831_BLOCP_MASK GENMASK(1, 0) + +#define RT4831_BLOCP_MINUA 900000 +#define RT4831_BLOCP_MAXUA 1800000 +#define RT4831_BLOCP_STEPUA 300000 struct rt4831_priv { struct device *dev; @@ -85,7 +92,7 @@ static int rt4831_parse_backlight_properties(struct rt4831_priv *priv, { struct device *dev = priv->dev; u8 propval; - u32 brightness; + u32 brightness, ocp_uA; unsigned int val = 0; int ret; @@ -120,6 +127,31 @@ static int rt4831_parse_backlight_properties(struct rt4831_priv *priv, if (ret) return ret; + /* + * This OCP level is used to protect and limit the inductor current. + * If inductor peak current reach the level, low-side MOSFET will be + * turned off. Meanwhile, the output channel current may be limited. + * To match the configured channel current, the inductor chosen must + * be higher than the OCP level. + * + * Not like the OVP level, the default 21V can be used in the most + * application. But if the chosen OCP level is smaller than needed, + * it will also affect the backlight channel output current to be + * smaller than the register setting. + */ + ret = device_property_read_u32(dev, "richtek,bled-ocp-microamp", + &ocp_uA); + if (!ret) { + ocp_uA = clamp_val(ocp_uA, RT4831_BLOCP_MINUA, + RT4831_BLOCP_MAXUA); + val = DIV_ROUND_UP(ocp_uA - RT4831_BLOCP_MINUA, + RT4831_BLOCP_STEPUA); + ret = regmap_update_bits(priv->regmap, RT4831_REG_BLOPT2, + RT4831_BLOCP_MASK, val); + if (ret) + return ret; + } + ret = device_property_read_u8(dev, "richtek,channel-use", &propval); if (ret) { dev_err(dev, "richtek,channel-use DT property missing\n"); @@ -172,15 +204,13 @@ static int rt4831_bl_probe(struct platform_device *pdev) return 0; } -static int rt4831_bl_remove(struct platform_device *pdev) +static void rt4831_bl_remove(struct platform_device *pdev) { struct rt4831_priv *priv = platform_get_drvdata(pdev); struct backlight_device *bl_dev = priv->bl; bl_dev->props.brightness = 0; backlight_update_status(priv->bl); - - return 0; } static const struct of_device_id __maybe_unused rt4831_bl_of_match[] = { @@ -200,4 +230,5 @@ static struct platform_driver rt4831_bl_driver = { module_platform_driver(rt4831_bl_driver); MODULE_AUTHOR("ChiYuan Huang <cy_huang@richtek.com>"); +MODULE_DESCRIPTION("Richtek RT4831 Backlight Driver"); MODULE_LICENSE("GPL v2"); |