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351 lines
9.7 KiB
351 lines
9.7 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* Copyright (C) 2022 Richtek Technology Corp. |
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* |
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* Author: ChiaEn Wu <[email protected]> |
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*/ |
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#include <linux/backlight.h> |
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#include <linux/bitfield.h> |
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#include <linux/bits.h> |
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#include <linux/gpio/consumer.h> |
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#include <linux/kernel.h> |
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#include <linux/minmax.h> |
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#include <linux/mod_devicetable.h> |
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#include <linux/module.h> |
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#include <linux/platform_device.h> |
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#include <linux/property.h> |
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#include <linux/regmap.h> |
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#define MT6370_REG_DEV_INFO 0x100 |
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#define MT6370_REG_BL_EN 0x1A0 |
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#define MT6370_REG_BL_BSTCTRL 0x1A1 |
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#define MT6370_REG_BL_PWM 0x1A2 |
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#define MT6370_REG_BL_DIM2 0x1A4 |
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#define MT6370_VENID_MASK GENMASK(7, 4) |
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#define MT6370_BL_EXT_EN_MASK BIT(7) |
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#define MT6370_BL_EN_MASK BIT(6) |
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#define MT6370_BL_CODE_MASK BIT(0) |
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#define MT6370_BL_CH_MASK GENMASK(5, 2) |
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#define MT6370_BL_CH_SHIFT 2 |
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#define MT6370_BL_DIM2_COMMON_MASK GENMASK(2, 0) |
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#define MT6370_BL_DIM2_COMMON_SHIFT 3 |
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#define MT6370_BL_DIM2_6372_MASK GENMASK(5, 0) |
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#define MT6370_BL_DIM2_6372_SHIFT 6 |
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#define MT6370_BL_PWM_EN_MASK BIT(7) |
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#define MT6370_BL_PWM_HYS_EN_MASK BIT(2) |
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#define MT6370_BL_PWM_HYS_SEL_MASK GENMASK(1, 0) |
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#define MT6370_BL_OVP_EN_MASK BIT(7) |
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#define MT6370_BL_OVP_SEL_MASK GENMASK(6, 5) |
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#define MT6370_BL_OVP_SEL_SHIFT 5 |
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#define MT6370_BL_OC_EN_MASK BIT(3) |
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#define MT6370_BL_OC_SEL_MASK GENMASK(2, 1) |
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#define MT6370_BL_OC_SEL_SHIFT 1 |
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#define MT6370_BL_PWM_HYS_TH_MIN_STEP 1 |
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#define MT6370_BL_PWM_HYS_TH_MAX_STEP 64 |
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#define MT6370_BL_OVP_MIN_UV 17000000 |
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#define MT6370_BL_OVP_MAX_UV 29000000 |
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#define MT6370_BL_OVP_STEP_UV 4000000 |
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#define MT6370_BL_OCP_MIN_UA 900000 |
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#define MT6370_BL_OCP_MAX_UA 1800000 |
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#define MT6370_BL_OCP_STEP_UA 300000 |
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#define MT6370_BL_MAX_COMMON_BRIGHTNESS 2048 |
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#define MT6370_BL_MAX_6372_BRIGHTNESS 16384 |
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#define MT6370_BL_MAX_CH 15 |
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enum { |
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MT6370_VID_COMMON = 1, |
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MT6370_VID_6372, |
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}; |
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struct mt6370_priv { |
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u8 dim2_mask; |
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u8 dim2_shift; |
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int def_max_brightness; |
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struct backlight_device *bl; |
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struct device *dev; |
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struct gpio_desc *enable_gpio; |
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struct regmap *regmap; |
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}; |
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static int mt6370_bl_update_status(struct backlight_device *bl_dev) |
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{ |
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struct mt6370_priv *priv = bl_get_data(bl_dev); |
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int brightness = backlight_get_brightness(bl_dev); |
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unsigned int enable_val; |
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u8 brightness_val[2]; |
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int ret; |
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if (brightness) { |
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brightness_val[0] = (brightness - 1) & priv->dim2_mask; |
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brightness_val[1] = (brightness - 1) >> priv->dim2_shift; |
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ret = regmap_raw_write(priv->regmap, MT6370_REG_BL_DIM2, |
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brightness_val, sizeof(brightness_val)); |
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if (ret) |
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return ret; |
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} |
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gpiod_set_value(priv->enable_gpio, !!brightness); |
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enable_val = brightness ? MT6370_BL_EN_MASK : 0; |
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return regmap_update_bits(priv->regmap, MT6370_REG_BL_EN, |
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MT6370_BL_EN_MASK, enable_val); |
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} |
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static int mt6370_bl_get_brightness(struct backlight_device *bl_dev) |
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{ |
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struct mt6370_priv *priv = bl_get_data(bl_dev); |
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unsigned int enable; |
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u8 brightness_val[2]; |
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int brightness, ret; |
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ret = regmap_read(priv->regmap, MT6370_REG_BL_EN, &enable); |
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if (ret) |
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return ret; |
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if (!(enable & MT6370_BL_EN_MASK)) |
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return 0; |
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ret = regmap_raw_read(priv->regmap, MT6370_REG_BL_DIM2, |
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brightness_val, sizeof(brightness_val)); |
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if (ret) |
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return ret; |
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brightness = brightness_val[1] << priv->dim2_shift; |
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brightness += brightness_val[0] & priv->dim2_mask; |
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return brightness + 1; |
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} |
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static const struct backlight_ops mt6370_bl_ops = { |
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.options = BL_CORE_SUSPENDRESUME, |
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.update_status = mt6370_bl_update_status, |
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.get_brightness = mt6370_bl_get_brightness, |
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}; |
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static int mt6370_init_backlight_properties(struct mt6370_priv *priv, |
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struct backlight_properties *props) |
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{ |
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struct device *dev = priv->dev; |
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u8 prop_val; |
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u32 brightness, ovp_uV, ocp_uA; |
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unsigned int mask, val; |
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int ret; |
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/* Vendor optional properties */ |
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val = 0; |
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if (device_property_read_bool(dev, "mediatek,bled-pwm-enable")) |
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val |= MT6370_BL_PWM_EN_MASK; |
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if (device_property_read_bool(dev, "mediatek,bled-pwm-hys-enable")) |
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val |= MT6370_BL_PWM_HYS_EN_MASK; |
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ret = device_property_read_u8(dev, |
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"mediatek,bled-pwm-hys-input-th-steps", |
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&prop_val); |
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if (!ret) { |
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prop_val = clamp_val(prop_val, |
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MT6370_BL_PWM_HYS_TH_MIN_STEP, |
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MT6370_BL_PWM_HYS_TH_MAX_STEP); |
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prop_val = prop_val <= 1 ? 0 : |
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prop_val <= 4 ? 1 : |
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prop_val <= 16 ? 2 : 3; |
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val |= prop_val; |
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} |
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ret = regmap_update_bits(priv->regmap, MT6370_REG_BL_PWM, |
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val, val); |
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if (ret) |
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return ret; |
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val = 0; |
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if (device_property_read_bool(dev, "mediatek,bled-ovp-shutdown")) |
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val |= MT6370_BL_OVP_EN_MASK; |
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ret = device_property_read_u32(dev, "mediatek,bled-ovp-microvolt", |
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&ovp_uV); |
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if (!ret) { |
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ovp_uV = clamp_val(ovp_uV, MT6370_BL_OVP_MIN_UV, |
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MT6370_BL_OVP_MAX_UV); |
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ovp_uV = DIV_ROUND_UP(ovp_uV - MT6370_BL_OVP_MIN_UV, |
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MT6370_BL_OVP_STEP_UV); |
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val |= ovp_uV << MT6370_BL_OVP_SEL_SHIFT; |
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} |
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if (device_property_read_bool(dev, "mediatek,bled-ocp-shutdown")) |
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val |= MT6370_BL_OC_EN_MASK; |
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ret = device_property_read_u32(dev, "mediatek,bled-ocp-microamp", |
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&ocp_uA); |
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if (!ret) { |
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ocp_uA = clamp_val(ocp_uA, MT6370_BL_OCP_MIN_UA, |
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MT6370_BL_OCP_MAX_UA); |
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ocp_uA = DIV_ROUND_UP(ocp_uA - MT6370_BL_OCP_MIN_UA, |
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MT6370_BL_OCP_STEP_UA); |
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val |= ocp_uA << MT6370_BL_OC_SEL_SHIFT; |
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} |
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ret = regmap_update_bits(priv->regmap, MT6370_REG_BL_BSTCTRL, |
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val, val); |
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if (ret) |
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return ret; |
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/* Common properties */ |
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ret = device_property_read_u32(dev, "max-brightness", &brightness); |
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if (ret) |
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brightness = priv->def_max_brightness; |
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props->max_brightness = min_t(u32, brightness, priv->def_max_brightness); |
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ret = device_property_read_u32(dev, "default-brightness", &brightness); |
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if (ret) |
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brightness = props->max_brightness; |
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props->brightness = min_t(u32, brightness, props->max_brightness); |
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val = 0; |
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if (device_property_read_bool(dev, "mediatek,bled-exponential-mode-enable")) { |
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val |= MT6370_BL_CODE_MASK; |
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props->scale = BACKLIGHT_SCALE_NON_LINEAR; |
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} else |
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props->scale = BACKLIGHT_SCALE_LINEAR; |
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ret = device_property_read_u8(dev, "mediatek,bled-channel-use", |
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&prop_val); |
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if (ret) { |
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dev_err(dev, "mediatek,bled-channel-use DT property missing\n"); |
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return ret; |
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} |
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if (!prop_val || prop_val > MT6370_BL_MAX_CH) { |
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dev_err(dev, |
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"No channel specified or over than upper bound (%d)\n", |
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prop_val); |
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return -EINVAL; |
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} |
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mask = MT6370_BL_EXT_EN_MASK | MT6370_BL_CH_MASK; |
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val |= prop_val << MT6370_BL_CH_SHIFT; |
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if (priv->enable_gpio) |
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val |= MT6370_BL_EXT_EN_MASK; |
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return regmap_update_bits(priv->regmap, MT6370_REG_BL_EN, mask, val); |
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} |
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static int mt6370_check_vendor_info(struct mt6370_priv *priv) |
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{ |
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/* |
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* Because MT6372 uses 14 bits to control the brightness, |
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* MT6370 and MT6371 use 11 bits. This function is used |
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* to check the vendor's ID and set the relative hardware |
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* mask, shift and default maximum brightness value that |
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* should be used. |
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*/ |
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unsigned int dev_info, hw_vid, of_vid; |
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int ret; |
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ret = regmap_read(priv->regmap, MT6370_REG_DEV_INFO, &dev_info); |
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if (ret) |
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return ret; |
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of_vid = (uintptr_t)device_get_match_data(priv->dev); |
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hw_vid = FIELD_GET(MT6370_VENID_MASK, dev_info); |
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hw_vid = (hw_vid == 0x9 || hw_vid == 0xb) ? MT6370_VID_6372 : MT6370_VID_COMMON; |
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if (hw_vid != of_vid) |
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return dev_err_probe(priv->dev, -EINVAL, |
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"Buggy DT, wrong compatible string\n"); |
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if (hw_vid == MT6370_VID_6372) { |
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priv->dim2_mask = MT6370_BL_DIM2_6372_MASK; |
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priv->dim2_shift = MT6370_BL_DIM2_6372_SHIFT; |
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priv->def_max_brightness = MT6370_BL_MAX_6372_BRIGHTNESS; |
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} else { |
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priv->dim2_mask = MT6370_BL_DIM2_COMMON_MASK; |
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priv->dim2_shift = MT6370_BL_DIM2_COMMON_SHIFT; |
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priv->def_max_brightness = MT6370_BL_MAX_COMMON_BRIGHTNESS; |
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} |
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return 0; |
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} |
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static int mt6370_bl_probe(struct platform_device *pdev) |
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{ |
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struct backlight_properties props = { |
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.type = BACKLIGHT_RAW, |
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}; |
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struct device *dev = &pdev->dev; |
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struct mt6370_priv *priv; |
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int ret; |
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priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); |
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if (!priv) |
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return -ENOMEM; |
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priv->dev = dev; |
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priv->regmap = dev_get_regmap(dev->parent, NULL); |
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if (!priv->regmap) |
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return dev_err_probe(dev, -ENODEV, "Failed to get regmap\n"); |
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ret = mt6370_check_vendor_info(priv); |
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if (ret) |
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return dev_err_probe(dev, ret, "Failed to check vendor info\n"); |
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priv->enable_gpio = devm_gpiod_get_optional(dev, "enable", |
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GPIOD_OUT_HIGH); |
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if (IS_ERR(priv->enable_gpio)) |
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return dev_err_probe(dev, PTR_ERR(priv->enable_gpio), |
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"Failed to get 'enable' gpio\n"); |
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ret = mt6370_init_backlight_properties(priv, &props); |
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if (ret) |
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return dev_err_probe(dev, ret, |
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"Failed to init backlight properties\n"); |
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priv->bl = devm_backlight_device_register(dev, pdev->name, dev, priv, |
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&mt6370_bl_ops, &props); |
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if (IS_ERR(priv->bl)) |
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return dev_err_probe(dev, PTR_ERR(priv->bl), |
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"Failed to register backlight\n"); |
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backlight_update_status(priv->bl); |
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platform_set_drvdata(pdev, priv); |
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return 0; |
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} |
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static int mt6370_bl_remove(struct platform_device *pdev) |
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{ |
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struct mt6370_priv *priv = platform_get_drvdata(pdev); |
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struct backlight_device *bl_dev = priv->bl; |
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bl_dev->props.brightness = 0; |
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backlight_update_status(priv->bl); |
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return 0; |
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} |
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static const struct of_device_id mt6370_bl_of_match[] = { |
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{ .compatible = "mediatek,mt6370-backlight", .data = (void *)MT6370_VID_COMMON }, |
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{ .compatible = "mediatek,mt6372-backlight", .data = (void *)MT6370_VID_6372 }, |
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{} |
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}; |
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MODULE_DEVICE_TABLE(of, mt6370_bl_of_match); |
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static struct platform_driver mt6370_bl_driver = { |
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.driver = { |
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.name = "mt6370-backlight", |
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.of_match_table = mt6370_bl_of_match, |
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}, |
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.probe = mt6370_bl_probe, |
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.remove = mt6370_bl_remove, |
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}; |
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module_platform_driver(mt6370_bl_driver); |
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MODULE_AUTHOR("ChiaEn Wu <[email protected]>"); |
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MODULE_DESCRIPTION("MediaTek MT6370 Backlight Driver"); |
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MODULE_LICENSE("GPL v2");
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