From: Linus Torvalds Date: Wed, 5 Oct 2022 17:45:15 +0000 (-0700) Subject: Merge tag 'backlight-next-6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/lee... X-Git-Tag: v6.6.17~6494 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=a47e60729d9624e931f988709ab76e043e2ee8b9;hp=7fb68b6c821be7165d5be5d8801d909912af9159;p=platform%2Fkernel%2Flinux-rpi.git Merge tag 'backlight-next-6.1' of git://git./linux/kernel/git/lee/backlight Pull backlight update from Lee Jones: - Add support for MediaTek MT6370 Backlight * tag 'backlight-next-6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/backlight: video: backlight: mt6370: Add MediaTek MT6370 support dt-bindings: backlight: Add MediaTek MT6370 backlight --- diff --git a/Documentation/devicetree/bindings/leds/backlight/mediatek,mt6370-backlight.yaml b/Documentation/devicetree/bindings/leds/backlight/mediatek,mt6370-backlight.yaml new file mode 100644 index 0000000..5533b65 --- /dev/null +++ b/Documentation/devicetree/bindings/leds/backlight/mediatek,mt6370-backlight.yaml @@ -0,0 +1,121 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/leds/backlight/mediatek,mt6370-backlight.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: MediaTek MT6370 Backlight + +maintainers: + - ChiaEn Wu + +description: | + This module is part of the MT6370 MFD device. + The MT6370 Backlight WLED driver supports up to a 29V output voltage for + 4 channels of 8 series WLEDs. Each channel supports up to 30mA of current + capability with 2048 current steps (11 bits, only for MT6370/MT6371) or + 16384 current steps (14 bits, only for MT6372) in exponential or linear + mapping curves. + +allOf: + - $ref: common.yaml# + +properties: + compatible: + enum: + - mediatek,mt6370-backlight + - mediatek,mt6372-backlight + + default-brightness: + minimum: 0 + + max-brightness: + minimum: 0 + + enable-gpios: + description: External backlight 'enable' pin + maxItems: 1 + + mediatek,bled-pwm-enable: + description: | + Enable external PWM input for backlight dimming + type: boolean + + mediatek,bled-pwm-hys-enable: + description: | + Enable the backlight input-hysteresis for PWM mode + type: boolean + + mediatek,bled-pwm-hys-input-th-steps: + $ref: /schemas/types.yaml#/definitions/uint8 + enum: [1, 4, 16, 64] + description: | + The selection of the upper and lower bounds threshold of backlight + PWM resolution. If we choose selection 64, the variation of PWM + resolution needs more than 64 steps. + + mediatek,bled-ovp-shutdown: + description: | + Enable the backlight shutdown when OVP level triggered + type: boolean + + mediatek,bled-ovp-microvolt: + enum: [17000000, 21000000, 25000000, 29000000] + description: | + Backlight OVP level selection. + + mediatek,bled-ocp-shutdown: + description: | + Enable the backlight shutdown when OCP level triggerred. + type: boolean + + mediatek,bled-ocp-microamp: + enum: [900000, 1200000, 1500000, 1800000] + description: | + Backlight OC level selection. + + mediatek,bled-exponential-mode-enable: + description: | + Enable the exponential mode of backlight brightness. If this property + is not enabled, the default is to use linear mode. + type: boolean + + mediatek,bled-channel-use: + $ref: /schemas/types.yaml#/definitions/uint8 + description: | + Backlight LED channel to be used. + Each bit mapping to: + - 0: CH4 + - 1: CH3 + - 2: CH2 + - 3: CH1 + minimum: 1 + maximum: 15 + +if: + properties: + compatible: + contains: + const: mediatek,mt6372-backlight + +then: + properties: + default-brightness: + maximum: 16384 + + max-brightness: + maximum: 16384 + +else: + properties: + default-brightness: + maximum: 2048 + + max-brightness: + maximum: 2048 + +required: + - compatible + - mediatek,bled-channel-use + +additionalProperties: false diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig index a003e02..936ba1e 100644 --- a/drivers/video/backlight/Kconfig +++ b/drivers/video/backlight/Kconfig @@ -268,6 +268,19 @@ config BACKLIGHT_MAX8925 If you have a LCD backlight connected to the WLED output of MAX8925 WLED output, say Y here to enable this driver. +config BACKLIGHT_MT6370 + tristate "MediaTek MT6370 Backlight Driver" + depends on MFD_MT6370 + help + This enables support for Mediatek MT6370 Backlight driver. + It's commonly used to drive the display WLED. There are 4 channels + inside, and each channel supports up to 30mA of current capability + with 2048 current steps (only for MT6370/MT6371) or 16384 current + steps (only for MT6372) in exponential or linear mapping curves. + + This driver can also be built as a module. If so, the module + will be called "mt6370-backlight". + config BACKLIGHT_APPLE tristate "Apple Backlight Driver" depends on X86 && ACPI diff --git a/drivers/video/backlight/Makefile b/drivers/video/backlight/Makefile index cae2c83..e815f3f 100644 --- a/drivers/video/backlight/Makefile +++ b/drivers/video/backlight/Makefile @@ -44,6 +44,7 @@ obj-$(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 0000000..623d4f2 --- /dev/null +++ b/drivers/video/backlight/mt6370-backlight.c @@ -0,0 +1,351 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2022 Richtek Technology Corp. + * + * Author: ChiaEn Wu + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#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_CODE_MASK BIT(0) +#define MT6370_BL_CH_MASK GENMASK(5, 2) +#define MT6370_BL_CH_SHIFT 2 +#define MT6370_BL_DIM2_COMMON_MASK GENMASK(2, 0) +#define MT6370_BL_DIM2_COMMON_SHIFT 3 +#define MT6370_BL_DIM2_6372_MASK GENMASK(5, 0) +#define MT6370_BL_DIM2_6372_SHIFT 6 +#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_OVP_SEL_SHIFT 5 +#define MT6370_BL_OC_EN_MASK BIT(3) +#define MT6370_BL_OC_SEL_MASK GENMASK(2, 1) +#define MT6370_BL_OC_SEL_SHIFT 1 + +#define MT6370_BL_PWM_HYS_TH_MIN_STEP 1 +#define MT6370_BL_PWM_HYS_TH_MAX_STEP 64 +#define MT6370_BL_OVP_MIN_UV 17000000 +#define MT6370_BL_OVP_MAX_UV 29000000 +#define MT6370_BL_OVP_STEP_UV 4000000 +#define MT6370_BL_OCP_MIN_UA 900000 +#define MT6370_BL_OCP_MAX_UA 1800000 +#define MT6370_BL_OCP_STEP_UA 300000 +#define MT6370_BL_MAX_COMMON_BRIGHTNESS 2048 +#define MT6370_BL_MAX_6372_BRIGHTNESS 16384 +#define MT6370_BL_MAX_CH 15 + +enum { + MT6370_VID_COMMON = 1, + MT6370_VID_6372, +}; + +struct mt6370_priv { + u8 dim2_mask; + u8 dim2_shift; + int def_max_brightness; + 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) & priv->dim2_mask; + brightness_val[1] = (brightness - 1) >> priv->dim2_shift; + + ret = regmap_raw_write(priv->regmap, MT6370_REG_BL_DIM2, + brightness_val, sizeof(brightness_val)); + if (ret) + return ret; + } + + gpiod_set_value(priv->enable_gpio, !!brightness); + + 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; + + brightness = brightness_val[1] << priv->dim2_shift; + brightness += brightness_val[0] & priv->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, +}; + +static int mt6370_init_backlight_properties(struct mt6370_priv *priv, + struct backlight_properties *props) +{ + struct device *dev = priv->dev; + u8 prop_val; + u32 brightness, ovp_uV, ocp_uA; + unsigned int mask, val; + int ret; + + /* Vendor optional properties */ + val = 0; + if (device_property_read_bool(dev, "mediatek,bled-pwm-enable")) + val |= MT6370_BL_PWM_EN_MASK; + + if (device_property_read_bool(dev, "mediatek,bled-pwm-hys-enable")) + val |= MT6370_BL_PWM_HYS_EN_MASK; + + ret = device_property_read_u8(dev, + "mediatek,bled-pwm-hys-input-th-steps", + &prop_val); + if (!ret) { + prop_val = clamp_val(prop_val, + MT6370_BL_PWM_HYS_TH_MIN_STEP, + MT6370_BL_PWM_HYS_TH_MAX_STEP); + prop_val = prop_val <= 1 ? 0 : + prop_val <= 4 ? 1 : + prop_val <= 16 ? 2 : 3; + val |= prop_val; + } + + ret = regmap_update_bits(priv->regmap, MT6370_REG_BL_PWM, + val, val); + if (ret) + return ret; + + val = 0; + if (device_property_read_bool(dev, "mediatek,bled-ovp-shutdown")) + val |= MT6370_BL_OVP_EN_MASK; + + ret = device_property_read_u32(dev, "mediatek,bled-ovp-microvolt", + &ovp_uV); + if (!ret) { + ovp_uV = clamp_val(ovp_uV, MT6370_BL_OVP_MIN_UV, + MT6370_BL_OVP_MAX_UV); + ovp_uV = DIV_ROUND_UP(ovp_uV - MT6370_BL_OVP_MIN_UV, + MT6370_BL_OVP_STEP_UV); + val |= ovp_uV << MT6370_BL_OVP_SEL_SHIFT; + } + + if (device_property_read_bool(dev, "mediatek,bled-ocp-shutdown")) + val |= MT6370_BL_OC_EN_MASK; + + ret = device_property_read_u32(dev, "mediatek,bled-ocp-microamp", + &ocp_uA); + if (!ret) { + ocp_uA = clamp_val(ocp_uA, MT6370_BL_OCP_MIN_UA, + MT6370_BL_OCP_MAX_UA); + ocp_uA = DIV_ROUND_UP(ocp_uA - MT6370_BL_OCP_MIN_UA, + MT6370_BL_OCP_STEP_UA); + val |= ocp_uA << MT6370_BL_OC_SEL_SHIFT; + } + + ret = regmap_update_bits(priv->regmap, MT6370_REG_BL_BSTCTRL, + val, val); + if (ret) + return ret; + + /* Common properties */ + ret = device_property_read_u32(dev, "max-brightness", &brightness); + if (ret) + brightness = priv->def_max_brightness; + + props->max_brightness = min_t(u32, brightness, priv->def_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); + + val = 0; + if (device_property_read_bool(dev, "mediatek,bled-exponential-mode-enable")) { + val |= MT6370_BL_CODE_MASK; + props->scale = BACKLIGHT_SCALE_NON_LINEAR; + } else + props->scale = BACKLIGHT_SCALE_LINEAR; + + 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 || prop_val > MT6370_BL_MAX_CH) { + dev_err(dev, + "No channel specified or over than upper bound (%d)\n", + prop_val); + return -EINVAL; + } + + mask = MT6370_BL_EXT_EN_MASK | MT6370_BL_CH_MASK; + val |= prop_val << MT6370_BL_CH_SHIFT; + + 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) +{ + /* + * Because MT6372 uses 14 bits to control the brightness, + * MT6370 and MT6371 use 11 bits. This function is used + * to check the vendor's ID and set the relative hardware + * mask, shift and default maximum brightness value that + * should be used. + */ + unsigned int dev_info, hw_vid, of_vid; + int ret; + + ret = regmap_read(priv->regmap, MT6370_REG_DEV_INFO, &dev_info); + if (ret) + return ret; + + of_vid = (uintptr_t)device_get_match_data(priv->dev); + hw_vid = FIELD_GET(MT6370_VENID_MASK, dev_info); + hw_vid = (hw_vid == 0x9 || hw_vid == 0xb) ? MT6370_VID_6372 : MT6370_VID_COMMON; + if (hw_vid != of_vid) + return dev_err_probe(priv->dev, -EINVAL, + "Buggy DT, wrong compatible string\n"); + + if (hw_vid == MT6370_VID_6372) { + priv->dim2_mask = MT6370_BL_DIM2_6372_MASK; + priv->dim2_shift = MT6370_BL_DIM2_6372_SHIFT; + priv->def_max_brightness = MT6370_BL_MAX_6372_BRIGHTNESS; + } else { + priv->dim2_mask = MT6370_BL_DIM2_COMMON_MASK; + priv->dim2_shift = MT6370_BL_DIM2_COMMON_SHIFT; + priv->def_max_brightness = MT6370_BL_MAX_COMMON_BRIGHTNESS; + } + + return 0; +} + +static int mt6370_bl_probe(struct platform_device *pdev) +{ + struct backlight_properties props = { + .type = BACKLIGHT_RAW, + }; + struct device *dev = &pdev->dev; + struct mt6370_priv *priv; + int ret; + + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + priv->dev = dev; + + priv->regmap = dev_get_regmap(dev->parent, NULL); + if (!priv->regmap) + return dev_err_probe(dev, -ENODEV, "Failed to get regmap\n"); + + ret = mt6370_check_vendor_info(priv); + if (ret) + return dev_err_probe(dev, ret, "Failed to check vendor info\n"); + + priv->enable_gpio = devm_gpiod_get_optional(dev, "enable", + GPIOD_OUT_HIGH); + if (IS_ERR(priv->enable_gpio)) + return dev_err_probe(dev, PTR_ERR(priv->enable_gpio), + "Failed to get 'enable' gpio\n"); + + ret = mt6370_init_backlight_properties(priv, &props); + if (ret) + return dev_err_probe(dev, ret, + "Failed to init backlight properties\n"); + + priv->bl = devm_backlight_device_register(dev, pdev->name, dev, priv, + &mt6370_bl_ops, &props); + if (IS_ERR(priv->bl)) + return dev_err_probe(dev, PTR_ERR(priv->bl), + "Failed to register backlight\n"); + + 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 mt6370_bl_of_match[] = { + { .compatible = "mediatek,mt6370-backlight", .data = (void *)MT6370_VID_COMMON }, + { .compatible = "mediatek,mt6372-backlight", .data = (void *)MT6370_VID_6372 }, + {} +}; +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 "); +MODULE_DESCRIPTION("MediaTek MT6370 Backlight Driver"); +MODULE_LICENSE("GPL v2");