From: ChiaEn Wu <chiaen_wu@xxxxxxxxxxx> Add Mediatek MT6370 Backlight support. Signed-off-by: ChiaEn Wu <chiaen_wu@xxxxxxxxxxx> --- drivers/video/backlight/Kconfig | 8 + drivers/video/backlight/Makefile | 1 + drivers/video/backlight/mt6370-backlight.c | 338 +++++++++++++++++++++ 3 files changed, 347 insertions(+) create mode 100644 drivers/video/backlight/mt6370-backlight.c diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig index a003e02e13ce..d9868fbe7488 100644 --- a/drivers/video/backlight/Kconfig +++ b/drivers/video/backlight/Kconfig @@ -268,6 +268,14 @@ config BACKLIGHT_MAX8925 If you have a LCD backlight connected to the WLED output of MAX8925 WLED output, say Y here to enable this driver. +config BACKLIGHT_MT6370 + tristate "Mediatek MT6370 Backlight Driver" + depends on MFD_MT6370 + help + Say Y here to enable MT6370 Backlight support. + It's commonly used to drive the display WLED. There're 4 channels + inisde, and each channel can provide up to 30mA current. + config BACKLIGHT_APPLE tristate "Apple Backlight Driver" depends on X86 && ACPI diff --git a/drivers/video/backlight/Makefile b/drivers/video/backlight/Makefile index cae2c83422ae..e815f3f1deff 100644 --- a/drivers/video/backlight/Makefile +++ b/drivers/video/backlight/Makefile @@ -44,6 +44,7 @@ obj-$(CONFIG_BACKLIGHT_LP855X) += lp855x_bl.o obj-$(CONFIG_BACKLIGHT_LP8788) += lp8788_bl.o obj-$(CONFIG_BACKLIGHT_LV5207LP) += lv5207lp.o obj-$(CONFIG_BACKLIGHT_MAX8925) += max8925_bl.o +obj-$(CONFIG_BACKLIGHT_MT6370) += mt6370-backlight.o obj-$(CONFIG_BACKLIGHT_OMAP1) += omap1_bl.o obj-$(CONFIG_BACKLIGHT_PANDORA) += pandora_bl.o obj-$(CONFIG_BACKLIGHT_PCF50633) += pcf50633-backlight.o diff --git a/drivers/video/backlight/mt6370-backlight.c b/drivers/video/backlight/mt6370-backlight.c new file mode 100644 index 000000000000..f8a8d33203ed --- /dev/null +++ b/drivers/video/backlight/mt6370-backlight.c @@ -0,0 +1,338 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <linux/backlight.h> +#include <linux/bitfield.h> +#include <linux/bits.h> +#include <linux/gpio/consumer.h> +#include <linux/gpio/driver.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> + +#define MT6370_REG_DEV_INFO 0x100 +#define MT6370_REG_BL_EN 0x1A0 +#define MT6370_REG_BL_BSTCTRL 0x1A1 +#define MT6370_REG_BL_PWM 0x1A2 +#define MT6370_REG_BL_DIM2 0x1A4 + +#define MT6370_VENID_MASK GENMASK(7, 4) +#define MT6370_BL_EXT_EN_MASK BIT(7) +#define MT6370_BL_EN_MASK BIT(6) +#define MT6370_BL_CONFIG_MASK BIT(0) +#define MT6370_BL_CH_MASK GENMASK(5, 2) +#define MT6370_BL_DIM2_MASK GENMASK(2, 0) +#define MT6370_BL_DUMMY_6372_MASK GENMASK(2, 0) +#define MT6370_BL_DIM2_6372_SHIFT 3 +#define MT6370_BL_PWM_EN_MASK BIT(7) +#define MT6370_BL_PWM_HYS_EN_MASK BIT(2) +#define MT6370_BL_PWM_HYS_SEL_MASK GENMASK(1, 0) +#define MT6370_BL_OVP_EN_MASK BIT(7) +#define MT6370_BL_OVP_SEL_MASK GENMASK(6, 5) +#define MT6370_BL_OC_EN_MASK BIT(3) +#define MT6370_BL_OC_SEL_MASK GENMASK(2, 1) + +#define MT6370_BL_MAX_BRIGHTNESS 2048 + +enum { + MT6370_VID_COMMON = 0, + MT6370_VID_6372, + MT6370_VID_MAX, +}; + +enum mt6370_prop_type { + MT6370_PARSE_TYPE_BOOL = 0, + MT6370_PARSE_TYPE_U8, + MT6370_PARSE_TYPE_MAX, +}; + +struct mt6370_priv { + int vid_type; + struct backlight_device *bl; + struct device *dev; + struct gpio_desc *enable_gpio; + struct regmap *regmap; +}; + +static int mt6370_bl_update_status(struct backlight_device *bl_dev) +{ + struct mt6370_priv *priv = bl_get_data(bl_dev); + int brightness = backlight_get_brightness(bl_dev); + unsigned int enable_val; + u8 brightness_val[2]; + int ret; + + if (brightness) { + brightness_val[0] = (brightness - 1) & MT6370_BL_DIM2_MASK; + brightness_val[1] = (brightness - 1) + >> fls(MT6370_BL_DIM2_MASK); + + if (priv->vid_type == MT6370_VID_6372) { + brightness_val[0] <<= MT6370_BL_DIM2_6372_SHIFT; + brightness_val[0] |= MT6370_BL_DUMMY_6372_MASK; + } + + ret = regmap_raw_write(priv->regmap, MT6370_REG_BL_DIM2, + brightness_val, sizeof(brightness_val)); + if (ret) + return ret; + } + + if (priv->enable_gpio) + gpiod_set_value(priv->enable_gpio, brightness ? 1 : 0); + + enable_val = brightness ? MT6370_BL_EN_MASK : 0; + return regmap_update_bits(priv->regmap, MT6370_REG_BL_EN, + MT6370_BL_EN_MASK, enable_val); +} + +static int mt6370_bl_get_brightness(struct backlight_device *bl_dev) +{ + struct mt6370_priv *priv = bl_get_data(bl_dev); + unsigned int enable; + u8 brightness_val[2]; + int brightness, ret; + + ret = regmap_read(priv->regmap, MT6370_REG_BL_EN, &enable); + if (ret) + return ret; + + if (!(enable & MT6370_BL_EN_MASK)) + return 0; + + ret = regmap_raw_read(priv->regmap, MT6370_REG_BL_DIM2, + brightness_val, sizeof(brightness_val)); + if (ret) + return ret; + + if (priv->vid_type == MT6370_VID_6372) + brightness_val[0] >>= MT6370_BL_DIM2_6372_SHIFT; + + brightness = brightness_val[1] << fls(MT6370_BL_DIM2_MASK); + brightness += (brightness_val[0] & MT6370_BL_DIM2_MASK); + + return brightness + 1; +} + +static const struct backlight_ops mt6370_bl_ops = { + .options = BL_CORE_SUSPENDRESUME, + .update_status = mt6370_bl_update_status, + .get_brightness = mt6370_bl_get_brightness, +}; + +#define MT6370_DT_PROP_DECL(_name, _type, _reg, _mask, _max, _inv) \ +{ \ + .name = "mediatek,bled-" #_name, \ + .type = MT6370_PARSE_TYPE_##_type, \ + .reg = _reg, \ + .mask = _mask, \ + .max_val = _max, \ + .invert = _inv, \ +} + +static int mt6370_init_backlight_properties(struct mt6370_priv *priv, + struct backlight_properties *props) +{ + struct device *dev = priv->dev; + u8 prop_val; + u32 brightness; + unsigned int mask, val; + static const struct { + char *name; + enum mt6370_prop_type type; + unsigned int reg; + unsigned int mask; + u8 max_val; + bool invert; + } vendor_opt_props[] = { + MT6370_DT_PROP_DECL(pwm-enable, BOOL, MT6370_REG_BL_PWM, + MT6370_BL_PWM_EN_MASK, 1, false), + MT6370_DT_PROP_DECL(pwm-hys-enable, BOOL, MT6370_REG_BL_PWM, + MT6370_BL_PWM_HYS_EN_MASK, 1, false), + MT6370_DT_PROP_DECL(pwm-hys-sel, U8, MT6370_REG_BL_PWM, + MT6370_BL_PWM_HYS_SEL_MASK, 3, false), + MT6370_DT_PROP_DECL(ovp-level-sel, U8, MT6370_REG_BL_BSTCTRL, + MT6370_BL_OVP_SEL_MASK, 3, false), + MT6370_DT_PROP_DECL(ovp-shutdown, BOOL, MT6370_REG_BL_BSTCTRL, + MT6370_BL_OVP_EN_MASK, 1, true), + MT6370_DT_PROP_DECL(ocp-level-sel, U8, MT6370_REG_BL_BSTCTRL, + MT6370_BL_OC_SEL_MASK, 3, false), + MT6370_DT_PROP_DECL(ocp-shutdown, BOOL, MT6370_REG_BL_BSTCTRL, + MT6370_BL_OC_EN_MASK, 1, true), + }, *prop_now; + int i, ret; + + /* vendor optional properties */ + for (i = 0; i < ARRAY_SIZE(vendor_opt_props); i++) { + prop_now = vendor_opt_props + i; + + switch (prop_now->type) { + case MT6370_PARSE_TYPE_BOOL: + if (device_property_read_bool(dev, prop_now->name)) + val = 1; + else + val = 0; + break; + case MT6370_PARSE_TYPE_U8: + ret = device_property_read_u8(dev, prop_now->name, + &prop_val); + /* Property not exist, keep value in default */ + if (ret) + continue; + + val = min_t(u8, prop_val, prop_now->max_val); + break; + default: + return -EINVAL; + } + + if (prop_now->invert) + val = prop_now->max_val - val; + + val <<= ffs(prop_now->mask) - 1; + + ret = regmap_update_bits(priv->regmap, prop_now->reg, + prop_now->mask, val); + if (ret) + return ret; + } + + /* common properties */ + ret = device_property_read_u32(dev, "max-brightness", &brightness); + if (ret) + brightness = MT6370_BL_MAX_BRIGHTNESS; + + props->max_brightness = min_t(u32, brightness, + MT6370_BL_MAX_BRIGHTNESS); + + ret = device_property_read_u32(dev, "default-brightness", &brightness); + if (ret) + brightness = props->max_brightness; + + props->brightness = min_t(u32, brightness, props->max_brightness); + + + ret = device_property_read_u8(dev, "mediatek,bled-channel-use", + &prop_val); + if (ret) { + dev_err(dev, "mediatek,bled-channel-use DT property missing\n"); + return ret; + } + + if (!prop_val) { + dev_err(dev, "No channel specified\n"); + return -EINVAL; + } + + mask = MT6370_BL_EXT_EN_MASK | MT6370_BL_CH_MASK; + val = prop_val << (ffs(MT6370_BL_CH_MASK) - 1); + + if (priv->enable_gpio) + val |= MT6370_BL_EXT_EN_MASK; + + return regmap_update_bits(priv->regmap, MT6370_REG_BL_EN, mask, val); +} + +static int mt6370_check_vendor_info(struct mt6370_priv *priv) +{ + unsigned int dev_info, vid; + int ret; + + ret = regmap_read(priv->regmap, MT6370_REG_DEV_INFO, &dev_info); + if (ret) + return ret; + + vid = FIELD_GET(MT6370_VENID_MASK, dev_info); + if (vid == 0x9 || vid == 0xb) + priv->vid_type = MT6370_VID_6372; + else + priv->vid_type = MT6370_VID_COMMON; + + return 0; +} + +static int mt6370_bl_probe(struct platform_device *pdev) +{ + struct mt6370_priv *priv; + struct backlight_properties 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 get regmap\n"); + return -ENODEV; + } + + ret = mt6370_check_vendor_info(priv); + if (ret) { + dev_err(&pdev->dev, "Failed to check vendor info (%d)\n", ret); + return ret; + } + + priv->enable_gpio = devm_gpiod_get_optional(&pdev->dev, "enable", + GPIOD_OUT_HIGH); + if (IS_ERR(priv->enable_gpio)) { + dev_err(&pdev->dev, "Failed to get 'enable' gpio\n"); + return PTR_ERR(priv->enable_gpio); + } + + ret = mt6370_init_backlight_properties(priv, &props); + if (ret) { + dev_err(&pdev->dev, "Failed to init backlight properties\n"); + return ret; + } + + priv->bl = devm_backlight_device_register(&pdev->dev, pdev->name, + &pdev->dev, priv, + &mt6370_bl_ops, &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 mt6370_bl_remove(struct platform_device *pdev) +{ + struct mt6370_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 mt6370_bl_of_match[] = { + { .compatible = "mediatek,mt6370-backlight", }, + {} +}; +MODULE_DEVICE_TABLE(of, mt6370_bl_of_match); + +static struct platform_driver mt6370_bl_driver = { + .driver = { + .name = "mt6370-backlight", + .of_match_table = mt6370_bl_of_match, + }, + .probe = mt6370_bl_probe, + .remove = mt6370_bl_remove, +}; +module_platform_driver(mt6370_bl_driver); + +MODULE_AUTHOR("ChiaEn Wu <chiaen_wu@xxxxxxxxxxx>"); +MODULE_DESCRIPTION("Mediatek MT6370 Backlight Driver"); +MODULE_LICENSE("GPL v2"); -- 2.25.1