Re: [PATCH v5 5/6] backlight: rt4831: Adds support for Richtek RT4831 backlight

Dear reviewers:

Didn't get any response about this backlight patch. Is there any part need to be refined?

cy_huang u0084500@gmail.com 於 2020年12月17日 週四 下午11:01寫道：

From: ChiYuan Huang cy_huang@richtek.com

Adds support for Richtek RT4831 backlight.

Signed-off-by: ChiYuan Huang cy_huang@richtek.com

drivers/video/backlight/Kconfig | 8 ++ drivers/video/backlight/Makefile | 1 + drivers/video/backlight/rt4831-backlight.c | 219 +++++++++++++++++++++++++++++ 3 files changed, 228 insertions(+) create mode 100644 drivers/video/backlight/rt4831-backlight.c

diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig index d83c87b..666bdb0 100644 --- a/drivers/video/backlight/Kconfig +++ b/drivers/video/backlight/Kconfig @@ -289,6 +289,14 @@ config BACKLIGHT_QCOM_WLED If you have the Qualcomm PMIC, say Y to enable a driver for the WLED block. Currently it supports PM8941 and PMI8998.

+config BACKLIGHT_RT4831

•   tristate "Richtek RT4831 Backlight Driver"
  

•   depends on MFD_RT4831
  

•   help
  

•     This enables support for Richtek RT4831 Backlight driver.
  

•     It's commont used to drive the display WLED. There're four channels
  

•     inisde, and each channel can provide up to 30mA current.
  

config BACKLIGHT_SAHARA tristate "Tabletkiosk Sahara Touch-iT Backlight Driver" depends on X86 diff --git a/drivers/video/backlight/Makefile b/drivers/video/backlight/Makefile index 685f3f1..cae2c83 100644 --- a/drivers/video/backlight/Makefile +++ b/drivers/video/backlight/Makefile @@ -49,6 +49,7 @@ obj-$(CONFIG_BACKLIGHT_PANDORA) += pandora_bl.o obj-$(CONFIG_BACKLIGHT_PCF50633) += pcf50633-backlight.o obj-$(CONFIG_BACKLIGHT_PWM) += pwm_bl.o obj-$(CONFIG_BACKLIGHT_QCOM_WLED) += qcom-wled.o +obj-$(CONFIG_BACKLIGHT_RT4831) += rt4831-backlight.o obj-$(CONFIG_BACKLIGHT_SAHARA) += kb3886_bl.o obj-$(CONFIG_BACKLIGHT_SKY81452) += sky81452-backlight.o obj-$(CONFIG_BACKLIGHT_TOSA) += tosa_bl.o diff --git a/drivers/video/backlight/rt4831-backlight.c b/drivers/video/backlight/rt4831-backlight.c new file mode 100644 index 00000000..816c4d6 --- /dev/null +++ b/drivers/video/backlight/rt4831-backlight.c @@ -0,0 +1,219 @@ +// SPDX-License-Identifier: GPL-2.0-only

+#include <dt-bindings/leds/rt4831-backlight.h> +#include <linux/backlight.h> +#include <linux/bitops.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/platform_device.h> +#include <linux/property.h> +#include <linux/regmap.h>

+#define RT4831_REG_BLCFG 0x02 +#define RT4831_REG_BLDIML 0x04 +#define RT4831_REG_ENABLE 0x08

+#define BL_MAX_BRIGHTNESS 2048

+#define RT4831_BLOVP_MASK GENMASK(7, 5) +#define RT4831_BLOVP_SHIFT 5 +#define RT4831_BLPWMEN_MASK BIT(0) +#define RT4831_BLEN_MASK BIT(4) +#define RT4831_BLCH_MASK GENMASK(3, 0) +#define RT4831_BLDIML_MASK GENMASK(2, 0) +#define RT4831_BLDIMH_MASK GENMASK(10, 3) +#define RT4831_BLDIMH_SHIFT 3

+struct rt4831_priv {

•   struct regmap *regmap;
  

•   struct mutex lock;
  

•   struct backlight_device *bl;
  

+};

+static int rt4831_bl_update_status(struct backlight_device *bl_dev) +{

•   struct rt4831_priv *priv = bl_get_data(bl_dev);
  

•   int brightness = backlight_get_brightness(bl_dev);
  

•   unsigned int enable = brightness ? RT4831_BLEN_MASK : 0;
  

•   u8 v[2];
  

•   int ret;
  

•   mutex_lock(&priv->lock);
  

•   if (brightness) {
  

•           v[0] = (brightness - 1) & RT4831_BLDIML_MASK;
  

•           v[1] = ((brightness - 1) & RT4831_BLDIMH_MASK) >> RT4831_BLDIMH_SHIFT;
  

•           ret = regmap_raw_write(priv->regmap, RT4831_REG_BLDIML, v, sizeof(v));
  

•           if (ret)
  

•                   goto unlock;
  

•   }
  

•   ret = regmap_update_bits(priv->regmap, RT4831_REG_ENABLE, RT4831_BLEN_MASK, enable);
  

+unlock:

•   mutex_unlock(&priv->lock);
  

•   return ret;
  

+}

+static int rt4831_bl_get_brightness(struct backlight_device *bl_dev) +{

•   struct rt4831_priv *priv = bl_get_data(bl_dev);
  

•   unsigned int val;
  

•   u8 v[2];
  

•   int ret;
  

•   mutex_lock(&priv->lock);
  

•   ret = regmap_read(priv->regmap, RT4831_REG_ENABLE, &val);
  

•   if (ret)
  

•           return ret;
  

•   if (!(val & RT4831_BLEN_MASK)) {
  

•           ret = 0;
  

•           goto unlock;
  

•   }
  

•   ret = regmap_raw_read(priv->regmap, RT4831_REG_BLDIML, v, sizeof(v));
  

•   if (ret)
  

•           goto unlock;
  

•   ret = (v[1] << RT4831_BLDIMH_SHIFT) + (v[0] & RT4831_BLDIML_MASK) + 1;
  

+unlock:

•   mutex_unlock(&priv->lock);
  

•   return ret;
  

+}

+static const struct backlight_ops rt4831_bl_ops = {

•   .options = BL_CORE_SUSPENDRESUME,
  

•   .update_status = rt4831_bl_update_status,
  

•   .get_brightness = rt4831_bl_get_brightness,
  

+};

+static int rt4831_init_device_properties(struct rt4831_priv *priv, struct device *dev,

•                                     struct backlight_properties *bl_props)
  

+{

•   u8 propval;
  

•   u32 brightness;
  

•   unsigned int val = 0;
  

•   int ret;
  

•   /* common properties */
  

•   ret = device_property_read_u32(dev, "max-brightness", &brightness);
  

•   if (ret) {
  

•           dev_warn(dev, "max-brightness DT property missing, use HW max as default\n");
  

•           brightness = BL_MAX_BRIGHTNESS;
  

•   }
  

•   bl_props->max_brightness = min_t(u32, brightness, BL_MAX_BRIGHTNESS);
  

•   ret = device_property_read_u32(dev, "default-brightness", &brightness);
  

•   if (ret) {
  

•           dev_warn(dev, "default-brightness DT property missing, use max limit as default\n");
  

•           brightness = bl_props->max_brightness;
  

•   }
  

•   bl_props->brightness = min_t(u32, brightness, bl_props->max_brightness);
  

•   /* vendor properties */
  

•   if (device_property_read_bool(dev, "richtek,pwm-enable"))
  

•           val = RT4831_BLPWMEN_MASK;
  

•   ret = regmap_update_bits(priv->regmap, RT4831_REG_BLCFG, RT4831_BLPWMEN_MASK, val);
  

•   if (ret)
  

•           return ret;
  

•   ret = device_property_read_u8(dev, "richtek,bled-ovp-sel", &propval);
  

•   if (ret) {
  

•           dev_warn(dev, "richtek,bled-ovp-sel DT property missing, use default 21V\n");
  

•           propval = RT4831_BLOVPLVL_21V;
  

•   }
  

•   propval = min_t(u8, propval, RT4831_BLOVPLVL_29V);
  

•   ret = regmap_update_bits(priv->regmap, RT4831_REG_BLCFG, RT4831_BLOVP_MASK,
  

•                            propval << RT4831_BLOVP_SHIFT);
  

•   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");
  

•           return ret;
  

•   }
  

•   if (!(propval & RT4831_BLCH_MASK)) {
  

•           dev_err(dev, "No channel specified\n");
  

•           return -EINVAL;
  

•   }
  

•   return regmap_update_bits(priv->regmap, RT4831_REG_ENABLE, RT4831_BLCH_MASK, propval);
  

+}

+static int rt4831_bl_probe(struct platform_device *pdev) +{

•   struct rt4831_priv *priv;
  

•   struct backlight_properties bl_props = { .type = BACKLIGHT_RAW, };
  

•   int ret;
  

•   priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
  

•   if (!priv)
  

•           return -ENOMEM;
  

•   mutex_init(&priv->lock);
  

•   priv->regmap = dev_get_regmap(pdev->dev.parent, NULL);
  

•   if (IS_ERR(priv->regmap)) {
  

•           dev_err(&pdev->dev, "Failed to init regmap\n");
  

•           return PTR_ERR(priv->regmap);
  

•   }
  

•   ret = rt4831_init_device_properties(priv, &pdev->dev, &bl_props);
  

•   if (ret) {
  

•           dev_err(&pdev->dev, "Failed to init device properties\n");
  

•           return ret;
  

•   }
  

•   priv->bl = devm_backlight_device_register(&pdev->dev, pdev->name, &pdev->dev, priv,
  

•                                             &rt4831_bl_ops, &bl_props);
  

•   if (IS_ERR(priv->bl)) {
  

•           dev_err(&pdev->dev, "Failed to register backlight\n");
  

•           return PTR_ERR(priv->bl);
  

•   }
  

•   backlight_update_status(priv->bl);
  

•   platform_set_drvdata(pdev, priv);
  

•   return 0;
  

+}

+static int 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[] = {

•   { .compatible = "richtek,rt4831-backlight", },
  

•   {}
  

+}; +MODULE_DEVICE_TABLE(of, rt4831_bl_of_match);

+static struct platform_driver rt4831_bl_driver = {

•   .driver = {
  

•           .name = "rt4831-backlight",
  

•           .of_match_table = rt4831_bl_of_match,
  

•   },
  

•   .probe = rt4831_bl_probe,
  

•   .remove = rt4831_bl_remove,
  

+}; +module_platform_driver(rt4831_bl_driver);

+MODULE_AUTHOR("ChiYuan Huang cy_huang@richtek.com");

+MODULE_LICENSE("GPL v2");

2.7.4