7cf208d73b
Update this driver to support a live device tree. Signed-off-by: Simon Glass <sjg@chromium.org> Acked-by: Anatolij Gustschin <agust@denx.de> Tested-by: Marcel Ziswiler <marcel.ziswiler@toradex.com> Tested-on: Beaver, Jetson-TK1
137 lines
3.3 KiB
C
137 lines
3.3 KiB
C
/*
|
|
* Copyright (c) 2016 Google, Inc
|
|
* Written by Simon Glass <sjg@chromium.org>
|
|
*
|
|
* SPDX-License-Identifier: GPL-2.0+
|
|
*/
|
|
|
|
#include <common.h>
|
|
#include <dm.h>
|
|
#include <backlight.h>
|
|
#include <pwm.h>
|
|
#include <asm/gpio.h>
|
|
#include <power/regulator.h>
|
|
|
|
DECLARE_GLOBAL_DATA_PTR;
|
|
|
|
struct pwm_backlight_priv {
|
|
struct udevice *reg;
|
|
struct gpio_desc enable;
|
|
struct udevice *pwm;
|
|
uint channel;
|
|
uint period_ns;
|
|
uint default_level;
|
|
uint min_level;
|
|
uint max_level;
|
|
};
|
|
|
|
static int pwm_backlight_enable(struct udevice *dev)
|
|
{
|
|
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) /
|
|
(priv->max_level - priv->min_level + 1);
|
|
ret = pwm_set_config(priv->pwm, priv->channel, priv->period_ns,
|
|
duty_cycle);
|
|
if (ret)
|
|
return ret;
|
|
ret = pwm_set_enable(priv->pwm, priv->channel, true);
|
|
if (ret)
|
|
return ret;
|
|
mdelay(10);
|
|
dm_gpio_set_value(&priv->enable, 1);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int pwm_backlight_ofdata_to_platdata(struct udevice *dev)
|
|
{
|
|
struct pwm_backlight_priv *priv = dev_get_priv(dev);
|
|
struct ofnode_phandle_args args;
|
|
int index, ret, count, len;
|
|
const u32 *cell;
|
|
|
|
debug("%s: start\n", __func__);
|
|
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;
|
|
}
|
|
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);
|
|
if (ret != -ENOENT)
|
|
return 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;
|
|
}
|
|
|
|
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;
|
|
}
|
|
priv->channel = args.args[0];
|
|
priv->period_ns = args.args[1];
|
|
|
|
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]);
|
|
} else {
|
|
priv->default_level = index;
|
|
priv->max_level = 255;
|
|
}
|
|
debug("%s: done\n", __func__);
|
|
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int pwm_backlight_probe(struct udevice *dev)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static const struct backlight_ops pwm_backlight_ops = {
|
|
.enable = pwm_backlight_enable,
|
|
};
|
|
|
|
static const struct udevice_id pwm_backlight_ids[] = {
|
|
{ .compatible = "pwm-backlight" },
|
|
{ }
|
|
};
|
|
|
|
U_BOOT_DRIVER(pwm_backlight) = {
|
|
.name = "pwm_backlight",
|
|
.id = UCLASS_PANEL_BACKLIGHT,
|
|
.of_match = pwm_backlight_ids,
|
|
.ops = &pwm_backlight_ops,
|
|
.ofdata_to_platdata = pwm_backlight_ofdata_to_platdata,
|
|
.probe = pwm_backlight_probe,
|
|
.priv_auto_alloc_size = sizeof(struct pwm_backlight_priv),
|
|
};
|