Re: [RESEND PATCH v6 4/4] backlight: rt4831: Adds support for Richtek RT4831 backlight

ChiYuan Huang
2021-04-26T10:50:37Z

Hi,

Daniel Thompson <daniel.thompson@linaro.org> 於 2021年4月26日 週一 下午6:19寫道：
>
> On Mon, Apr 26, 2021 at 03:18:11PM +0800, cy_huang wrote:
> > From: ChiYuan Huang <cy_huang@richtek.com>
> >
> > Adds support for Richtek RT4831 backlight.
> >
> > Signed-off-by: ChiYuan Huang <cy_huang@richtek.com>
> > Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
> > ---
> > Resend this v6 patch series to loop devicetree reviewers.
> >
> > For next, if the typo in Kconfig 'common' to 'commonly' can be added the below line
> > Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
> > ---
>
> This isn't the best way to handle feedback from multiple maintainers.
>
> It is great to see you are keeping track of feedback. However it doesn't
> make sense to RESEND an old patchset and acknowledge that you haven't
> fixed a typo yet.
>
> It would be better to fix the typo and to resend a v7.
>
You can refer to the below reply
https://lkml.org/lkml/2021/4/23/229

>
> Daniel.
>
>
> > drivers/video/backlight/Kconfig | 8 ++
> > drivers/video/backlight/Makefile | 1 +
> > drivers/video/backlight/rt4831-backlight.c | 203 +++++++++++++++++++++++++++++
> > 3 files changed, 212 insertions(+)
> > create mode 100644 drivers/video/backlight/rt4831-backlight.c
> >
> > diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig
> > index d83c87b..de96441 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 common 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..42155c7
> > --- /dev/null
> > +++ b/drivers/video/backlight/rt4831-backlight.c
> > @@ -0,0 +1,203 @@
> > +// 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/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 RT4831_BLMAX_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 device *dev;
> > + struct regmap *regmap;
> > + 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;
> > +
> > + 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)
> > + return ret;
> > + }
> > +
> > + return regmap_update_bits(priv->regmap, RT4831_REG_ENABLE, RT4831_BLEN_MASK, enable);
> > +
> > +}
> > +
> > +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;
> > +
> > + ret = regmap_read(priv->regmap, RT4831_REG_ENABLE, &val);
> > + if (ret)
> > + return ret;
> > +
> > + if (!(val & RT4831_BLEN_MASK))
> > + return 0;
> > +
> > + ret = regmap_raw_read(priv->regmap, RT4831_REG_BLDIML, v, sizeof(v));
> > + if (ret)
> > + return ret;
> > +
> > + ret = (v[1] << RT4831_BLDIMH_SHIFT) + (v[0] & RT4831_BLDIML_MASK) + 1;
> > +
> > + 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_parse_backlight_properties(struct rt4831_priv *priv,
> > + struct backlight_properties *bl_props)
> > +{
> > + struct device *dev = priv->dev;
> > + u8 propval;
> > + u32 brightness;
> > + unsigned int val = 0;
> > + int ret;
> > +
> > + /* common properties */
> > + ret = device_property_read_u32(dev, "max-brightness", &brightness);
> > + if (ret)
> > + brightness = RT4831_BLMAX_BRIGHTNESS;
> > +
> > + bl_props->max_brightness = min_t(u32, brightness, RT4831_BLMAX_BRIGHTNESS);
> > +
> > + ret = device_property_read_u32(dev, "default-brightness", &brightness);
> > + if (ret)
> > + 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)
> > + 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,
> > + .scale = BACKLIGHT_SCALE_LINEAR };
> > + int ret;
> > +
> > + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
> > + if (!priv)
> > + return -ENOMEM;
> > +
> > + priv->dev = &pdev->dev;
> > +
> > + priv->regmap = dev_get_regmap(pdev->dev.parent, NULL);
> > + if (!priv->regmap) {
> > + dev_err(&pdev->dev, "Failed to init regmap\n");
> > + return -ENODEV;
> > + }
> > +
> > + ret = rt4831_parse_backlight_properties(priv, &bl_props);
> > + if (ret) {
> > + dev_err(&pdev->dev, "Failed to parse backlight 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
> >