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133 lines
3.3 KiB
133 lines
3.3 KiB
// SPDX-License-Identifier: GPL-2.0+ |
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/* |
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* Copyright (c) 2016 Google, Inc |
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* Written by Simon Glass <[email protected]> |
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*/ |
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#include <common.h> |
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#include <dm.h> |
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#include <backlight.h> |
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#include <pwm.h> |
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#include <asm/gpio.h> |
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#include <power/regulator.h> |
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struct pwm_backlight_priv { |
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struct udevice *reg; |
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struct gpio_desc enable; |
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struct udevice *pwm; |
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uint channel; |
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uint period_ns; |
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uint default_level; |
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uint min_level; |
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uint max_level; |
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}; |
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static int pwm_backlight_enable(struct udevice *dev) |
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{ |
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struct pwm_backlight_priv *priv = dev_get_priv(dev); |
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struct dm_regulator_uclass_platdata *plat; |
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uint duty_cycle; |
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int ret; |
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if (priv->reg) { |
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plat = dev_get_uclass_platdata(priv->reg); |
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debug("%s: Enable '%s', regulator '%s'/'%s'\n", __func__, |
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dev->name, priv->reg->name, plat->name); |
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ret = regulator_set_enable(priv->reg, true); |
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if (ret) { |
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debug("%s: Cannot enable regulator for PWM '%s'\n", |
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__func__, dev->name); |
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return ret; |
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} |
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mdelay(120); |
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} |
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duty_cycle = priv->period_ns * (priv->default_level - priv->min_level) / |
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(priv->max_level - priv->min_level + 1); |
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ret = pwm_set_config(priv->pwm, priv->channel, priv->period_ns, |
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duty_cycle); |
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if (ret) |
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return ret; |
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ret = pwm_set_enable(priv->pwm, priv->channel, true); |
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if (ret) |
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return ret; |
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mdelay(10); |
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dm_gpio_set_value(&priv->enable, 1); |
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return 0; |
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} |
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static int pwm_backlight_ofdata_to_platdata(struct udevice *dev) |
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{ |
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struct pwm_backlight_priv *priv = dev_get_priv(dev); |
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struct ofnode_phandle_args args; |
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int index, ret, count, len; |
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const u32 *cell; |
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debug("%s: start\n", __func__); |
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ret = uclass_get_device_by_phandle(UCLASS_REGULATOR, dev, |
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"power-supply", &priv->reg); |
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if (ret) |
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debug("%s: Cannot get power supply: ret=%d\n", __func__, ret); |
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ret = gpio_request_by_name(dev, "enable-gpios", 0, &priv->enable, |
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GPIOD_IS_OUT); |
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if (ret) { |
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debug("%s: Warning: cannot get enable GPIO: ret=%d\n", |
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__func__, ret); |
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if (ret != -ENOENT) |
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return ret; |
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} |
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ret = dev_read_phandle_with_args(dev, "pwms", "#pwm-cells", 0, 0, |
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&args); |
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if (ret) { |
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debug("%s: Cannot get PWM phandle: ret=%d\n", __func__, ret); |
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return ret; |
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} |
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ret = uclass_get_device_by_ofnode(UCLASS_PWM, args.node, &priv->pwm); |
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if (ret) { |
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debug("%s: Cannot get PWM: ret=%d\n", __func__, ret); |
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return ret; |
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} |
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priv->channel = args.args[0]; |
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priv->period_ns = args.args[1]; |
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index = dev_read_u32_default(dev, "default-brightness-level", 255); |
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cell = dev_read_prop(dev, "brightness-levels", &len); |
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count = len / sizeof(u32); |
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if (cell && count > index) { |
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priv->default_level = fdt32_to_cpu(cell[index]); |
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priv->max_level = fdt32_to_cpu(cell[count - 1]); |
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} else { |
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priv->default_level = index; |
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priv->max_level = 255; |
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} |
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debug("%s: done\n", __func__); |
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return 0; |
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} |
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static int pwm_backlight_probe(struct udevice *dev) |
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{ |
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return 0; |
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} |
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static const struct backlight_ops pwm_backlight_ops = { |
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.enable = pwm_backlight_enable, |
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}; |
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static const struct udevice_id pwm_backlight_ids[] = { |
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{ .compatible = "pwm-backlight" }, |
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{ } |
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}; |
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U_BOOT_DRIVER(pwm_backlight) = { |
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.name = "pwm_backlight", |
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.id = UCLASS_PANEL_BACKLIGHT, |
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.of_match = pwm_backlight_ids, |
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.ops = &pwm_backlight_ops, |
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.ofdata_to_platdata = pwm_backlight_ofdata_to_platdata, |
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.probe = pwm_backlight_probe, |
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.priv_auto_alloc_size = sizeof(struct pwm_backlight_priv), |
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};
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