forked from OERV-BSP/u-boot
bf2d1902f4
Add support for Skyworks AAT2870 LED Backlight Driver and Multiple LDO Lighting Management Unit. Only backlight is supported as for now. Supported backlight level range is from 2 to 255 with step of 1. Tested-by: Ion Agorria <ion@agorria.com> Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
133 lines
3.3 KiB
C
133 lines
3.3 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* Copyright (c) 2024 Svyatoslav Ryhel <clamor95@gmail.com>
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*/
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#define LOG_CATEGORY UCLASS_PANEL_BACKLIGHT
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#include <backlight.h>
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#include <dm.h>
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#include <i2c.h>
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#include <log.h>
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#include <linux/err.h>
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#include <asm/gpio.h>
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#include <power/regulator.h>
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#define AAT2870_BL_MIN_BRIGHTNESS 0x01
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#define AAT2870_BL_DEF_BRIGHTNESS 0x64
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#define AAT2870_BL_MAX_BRIGHTNESS 0xff
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#define AAT2870_BL_CH_EN 0x00
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#define AAT2870_BLM 0x01
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#define AAT2870_BL_CH_ALL 0xff
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#define AAT2870_CURRENT_MAX 27900000
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#define AAT2870_CURRENT_STEP 900000
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struct aat2870_backlight_priv {
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struct gpio_desc enable_gpio;
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int channels;
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int max_current;
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};
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static int aat2870_backlight_enable(struct udevice *dev)
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{
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struct aat2870_backlight_priv *priv = dev_get_priv(dev);
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int ret;
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dm_gpio_set_value(&priv->enable_gpio, 1);
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/* Enable backlight for defined set of channels */
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ret = dm_i2c_reg_write(dev, AAT2870_BL_CH_EN, priv->channels);
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if (ret)
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return ret;
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return 0;
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}
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static int aat2870_backlight_set_brightness(struct udevice *dev, int percent)
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{
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struct aat2870_backlight_priv *priv = dev_get_priv(dev);
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int brightness, ret;
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if (percent == BACKLIGHT_DEFAULT)
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percent = AAT2870_BL_DEF_BRIGHTNESS;
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if (percent < AAT2870_BL_MIN_BRIGHTNESS)
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percent = AAT2870_BL_MIN_BRIGHTNESS;
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if (percent > AAT2870_BL_MAX_BRIGHTNESS)
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percent = AAT2870_BL_MAX_BRIGHTNESS;
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brightness = percent * priv->max_current;
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brightness /= AAT2870_BL_MAX_BRIGHTNESS;
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/* Set brightness level */
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ret = dm_i2c_reg_write(dev, AAT2870_BLM, brightness);
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if (ret)
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return ret;
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return 0;
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}
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static int aat2870_backlight_of_to_plat(struct udevice *dev)
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{
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struct aat2870_backlight_priv *priv = dev_get_priv(dev);
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int ret;
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ret = gpio_request_by_name(dev, "enable-gpios", 0,
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&priv->enable_gpio, GPIOD_IS_OUT);
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if (ret) {
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log_err("%s: cannot get enable-gpios (%d)\n",
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__func__, ret);
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return ret;
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}
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/* Backlight is one of children but has no dedicated driver */
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ofnode backlight = ofnode_find_subnode(dev_ofnode(dev), "backlight");
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if (ofnode_valid(backlight) && ofnode_is_enabled(backlight)) {
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/* Number of channel is equal to bit number */
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priv->channels = dev_read_u32_default(dev, "channels", AAT2870_BL_CH_ALL);
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if (priv->channels != AAT2870_BL_CH_ALL)
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priv->channels = BIT(priv->channels);
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/* 450mA - 27900mA range with a 900mA step */
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priv->max_current = dev_read_u32_default(dev, "current-max-microamp",
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AAT2870_CURRENT_MAX);
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priv->max_current /= AAT2870_CURRENT_STEP;
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}
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return 0;
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}
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static int aat2870_backlight_probe(struct udevice *dev)
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{
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if (device_get_uclass_id(dev->parent) != UCLASS_I2C)
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return -EPROTONOSUPPORT;
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return 0;
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}
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static const struct backlight_ops aat2870_backlight_ops = {
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.enable = aat2870_backlight_enable,
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.set_brightness = aat2870_backlight_set_brightness,
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};
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static const struct udevice_id aat2870_backlight_ids[] = {
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{ .compatible = "analogictech,aat2870" },
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{ .compatible = "skyworks,aat2870" },
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{ }
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};
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U_BOOT_DRIVER(aat2870_backlight) = {
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.name = "aat2870_backlight",
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.id = UCLASS_PANEL_BACKLIGHT,
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.of_match = aat2870_backlight_ids,
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.of_to_plat = aat2870_backlight_of_to_plat,
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.probe = aat2870_backlight_probe,
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.ops = &aat2870_backlight_ops,
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.priv_auto = sizeof(struct aat2870_backlight_priv),
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};
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