+// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (c) 2016 Google, Inc
* Written by Simon Glass <sjg@chromium.org>
- *
- * SPDX-License-Identifier: GPL-2.0+
*/
+#define LOG_CATEGORY UCLASS_PANEL_BACKLIGHT
+
#include <common.h>
#include <dm.h>
#include <backlight.h>
#include <asm/gpio.h>
#include <power/regulator.h>
-DECLARE_GLOBAL_DATA_PTR;
-
+/**
+ * Private information for the PWM backlight
+ *
+ * If @num_levels is 0 then the levels are simple values with the backlight
+ * value going between the minimum (default 0) and the maximum (default 255).
+ * Otherwise the levels are an index into @levels (0..n-1).
+ *
+ * @reg: Regulator to enable to turn the backlight on (NULL if none)
+ * @enable, GPIO to set to enable the backlight (can be missing)
+ * @pwm: PWM to use to change the backlight brightness
+ * @channel: PWM channel to use
+ * @period_ns: Period of the backlight in nanoseconds
+ * @levels: Levels for the backlight, or NULL if not using indexed levels
+ * @num_levels: Number of levels
+ * @cur_level: Current level for the backlight (index or value)
+ * @default_level: Default level for the backlight (index or value)
+ * @min_level: Minimum level of the backlight (full off)
+ * @min_level: Maximum level of the backlight (full on)
+ * @enabled: true if backlight is enabled
+ */
struct pwm_backlight_priv {
struct udevice *reg;
struct gpio_desc enable;
struct udevice *pwm;
uint channel;
uint period_ns;
+ /*
+ * the polarity of one PWM
+ * 0: normal polarity
+ * 1: inverted polarity
+ */
+ bool polarity;
+ u32 *levels;
+ int num_levels;
uint default_level;
+ int cur_level;
uint min_level;
uint max_level;
+ bool enabled;
};
-static int pwm_backlight_enable(struct udevice *dev)
+static int set_pwm(struct pwm_backlight_priv *priv)
{
- struct pwm_backlight_priv *priv = dev_get_priv(dev);
- struct dm_regulator_uclass_platdata *plat;
uint duty_cycle;
int ret;
- plat = dev_get_uclass_platdata(priv->reg);
- debug("%s: Enable '%s', regulator '%s'/'%s'\n", __func__, dev->name,
- priv->reg->name, plat->name);
- ret = regulator_set_enable(priv->reg, true);
- if (ret) {
- debug("%s: Cannot enable regulator for PWM '%s'\n", __func__,
- dev->name);
- return ret;
- }
- mdelay(120);
-
- duty_cycle = priv->period_ns * (priv->default_level - priv->min_level) /
+ duty_cycle = priv->period_ns * (priv->cur_level - priv->min_level) /
(priv->max_level - priv->min_level + 1);
ret = pwm_set_config(priv->pwm, priv->channel, priv->period_ns,
duty_cycle);
if (ret)
- return ret;
+ return log_ret(ret);
+
+ ret = pwm_set_invert(priv->pwm, priv->channel, priv->polarity);
+ return log_ret(ret);
+}
+
+static int enable_sequence(struct udevice *dev, int seq)
+{
+ struct pwm_backlight_priv *priv = dev_get_priv(dev);
+ int ret;
+
+ switch (seq) {
+ case 0:
+ if (priv->reg) {
+ __maybe_unused struct dm_regulator_uclass_platdata
+ *plat;
+
+ plat = dev_get_uclass_platdata(priv->reg);
+ log_debug("Enable '%s', regulator '%s'/'%s'\n",
+ dev->name, priv->reg->name, plat->name);
+ ret = regulator_set_enable(priv->reg, true);
+ if (ret) {
+ log_debug("Cannot enable regulator for PWM '%s'\n",
+ dev->name);
+ return log_ret(ret);
+ }
+ mdelay(120);
+ }
+ break;
+ case 1:
+ mdelay(10);
+ dm_gpio_set_value(&priv->enable, 1);
+ break;
+ }
+
+ return 0;
+}
+
+static int pwm_backlight_enable(struct udevice *dev)
+{
+ struct pwm_backlight_priv *priv = dev_get_priv(dev);
+ int ret;
+
+ ret = enable_sequence(dev, 0);
+ if (ret)
+ return log_ret(ret);
+ ret = set_pwm(priv);
+ if (ret)
+ return log_ret(ret);
ret = pwm_set_enable(priv->pwm, priv->channel, true);
if (ret)
- return ret;
- mdelay(10);
- dm_gpio_set_value(&priv->enable, 1);
+ return log_ret(ret);
+ ret = enable_sequence(dev, 1);
+ if (ret)
+ return log_ret(ret);
+ priv->enabled = true;
+
+ return 0;
+}
+
+static int pwm_backlight_set_brightness(struct udevice *dev, int percent)
+{
+ struct pwm_backlight_priv *priv = dev_get_priv(dev);
+ bool disable = false;
+ int level;
+ int ret;
+
+ if (!priv->enabled) {
+ ret = enable_sequence(dev, 0);
+ if (ret)
+ return log_ret(ret);
+ }
+ if (percent == BACKLIGHT_OFF) {
+ disable = true;
+ percent = 0;
+ }
+ if (percent == BACKLIGHT_DEFAULT) {
+ level = priv->default_level;
+ } else {
+ if (priv->levels) {
+ level = priv->levels[percent * (priv->num_levels - 1)
+ / 100];
+ } else {
+ level = priv->min_level +
+ (priv->max_level - priv->min_level) *
+ percent / 100;
+ }
+ }
+ priv->cur_level = level;
+
+ ret = set_pwm(priv);
+ if (ret)
+ return log_ret(ret);
+ if (!priv->enabled) {
+ ret = enable_sequence(dev, 1);
+ if (ret)
+ return log_ret(ret);
+ priv->enabled = true;
+ }
+ if (disable) {
+ dm_gpio_set_value(&priv->enable, 0);
+ if (priv->reg) {
+ ret = regulator_set_enable(priv->reg, false);
+ if (ret)
+ return log_ret(ret);
+ }
+ priv->enabled = false;
+ }
return 0;
}
int index, ret, count, len;
const u32 *cell;
- debug("%s: start\n", __func__);
+ log_debug("start\n");
ret = uclass_get_device_by_phandle(UCLASS_REGULATOR, dev,
"power-supply", &priv->reg);
- if (ret) {
- debug("%s: Cannot get power supply: ret=%d\n", __func__, ret);
- return ret;
- }
+ if (ret)
+ log_debug("Cannot get power supply: ret=%d\n", ret);
ret = gpio_request_by_name(dev, "enable-gpios", 0, &priv->enable,
GPIOD_IS_OUT);
if (ret) {
- debug("%s: Warning: cannot get enable GPIO: ret=%d\n",
- __func__, ret);
+ log_debug("Warning: cannot get enable GPIO: ret=%d\n", ret);
if (ret != -ENOENT)
- return ret;
+ return log_ret(ret);
}
ret = dev_read_phandle_with_args(dev, "pwms", "#pwm-cells", 0, 0,
&args);
if (ret) {
- debug("%s: Cannot get PWM phandle: ret=%d\n", __func__, ret);
- return ret;
+ log_debug("Cannot get PWM phandle: ret=%d\n", ret);
+ return log_ret(ret);
}
ret = uclass_get_device_by_ofnode(UCLASS_PWM, args.node, &priv->pwm);
if (ret) {
- debug("%s: Cannot get PWM: ret=%d\n", __func__, ret);
- return ret;
+ log_debug("Cannot get PWM: ret=%d\n", ret);
+ return log_ret(ret);
}
+ if (args.args_count < 2)
+ return log_msg_ret("Not enough arguments to pwm\n", -EINVAL);
priv->channel = args.args[0];
priv->period_ns = args.args[1];
+ if (args.args_count > 2)
+ priv->polarity = args.args[2];
index = dev_read_u32_default(dev, "default-brightness-level", 255);
cell = dev_read_prop(dev, "brightness-levels", &len);
count = len / sizeof(u32);
if (cell && count > index) {
- priv->default_level = fdt32_to_cpu(cell[index]);
- priv->max_level = fdt32_to_cpu(cell[count - 1]);
+ priv->levels = malloc(len);
+ if (!priv->levels)
+ return log_ret(-ENOMEM);
+ dev_read_u32_array(dev, "brightness-levels", priv->levels,
+ count);
+ priv->num_levels = count;
+ priv->default_level = priv->levels[index];
+ priv->max_level = priv->levels[count - 1];
} else {
priv->default_level = index;
priv->max_level = 255;
}
- debug("%s: done\n", __func__);
+ priv->cur_level = priv->default_level;
+ log_debug("done\n");
return 0;
}
static const struct backlight_ops pwm_backlight_ops = {
- .enable = pwm_backlight_enable,
+ .enable = pwm_backlight_enable,
+ .set_brightness = pwm_backlight_set_brightness,
};
static const struct udevice_id pwm_backlight_ids[] = {
projects / oweals / u-boot.git / blobdiff