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// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2022 VK
* Author: Ivan Vozvakhov <i.vozvakhov@vk.team>
*/
#include <common.h>
#include <dm.h>
#include <errno.h>
#include <led.h>
#include <malloc.h>
#include <dm/lists.h>
#include <pwm.h>
#define LEDS_PWM_DRIVER_NAME "led_pwm"
struct led_pwm_priv {
struct udevice *pwm;
uint period; /* period in ns */
uint duty; /* duty cycle in ns */
uint channel; /* pwm channel number */
bool active_low; /* pwm polarity */
bool enabled;
};
static int led_pwm_enable(struct udevice *dev)
{
struct led_pwm_priv *priv = dev_get_priv(dev);
int ret;
ret = pwm_set_invert(priv->pwm, priv->channel, priv->active_low);
if (ret)
return ret;
ret = pwm_set_config(priv->pwm, priv->channel, priv->period, priv->duty);
if (ret)
return ret;
ret = pwm_set_enable(priv->pwm, priv->channel, true);
if (ret)
return ret;
priv->enabled = true;
return 0;
}
static int led_pwm_disable(struct udevice *dev)
{
struct led_pwm_priv *priv = dev_get_priv(dev);
int ret;
ret = pwm_set_config(priv->pwm, priv->channel, priv->period, 0);
if (ret)
return ret;
ret = pwm_set_enable(priv->pwm, priv->channel, false);
if (ret)
return ret;
priv->enabled = false;
return 0;
}
static int led_pwm_set_state(struct udevice *dev, enum led_state_t state)
{
struct led_pwm_priv *priv = dev_get_priv(dev);
int ret;
switch (state) {
case LEDST_OFF:
ret = led_pwm_disable(dev);
break;
case LEDST_ON:
ret = led_pwm_enable(dev);
break;
case LEDST_TOGGLE:
ret = (priv->enabled) ? led_pwm_disable(dev) : led_pwm_enable(dev);
break;
default:
ret = -ENOSYS;
}
return ret;
}
static enum led_state_t led_pwm_get_state(struct udevice *dev)
{
struct led_pwm_priv *priv = dev_get_priv(dev);
return (priv->enabled) ? LEDST_ON : LEDST_OFF;
}
static int led_pwm_probe(struct udevice *dev)
{
struct led_pwm_priv *priv = dev_get_priv(dev);
return led_pwm_set_state(dev, (priv->enabled) ? LEDST_ON : LEDST_OFF);
}
static int led_pwm_of_to_plat(struct udevice *dev)
{
struct led_pwm_priv *priv = dev_get_priv(dev);
struct ofnode_phandle_args args;
uint def_brightness, max_brightness;
int ret;
ret = dev_read_phandle_with_args(dev, "pwms", "#pwm-cells", 0, 0, &args);
if (ret)
return ret;
ret = uclass_get_device_by_ofnode(UCLASS_PWM, args.node, &priv->pwm);
if (ret)
return ret;
priv->channel = args.args[0];
priv->period = args.args[1];
priv->active_low = dev_read_bool(dev, "active-low");
def_brightness = dev_read_u32_default(dev, "u-boot,default-brightness", 0);
max_brightness = dev_read_u32_default(dev, "max-brightness", 255);
priv->enabled = !!def_brightness;
/*
* No need to handle pwm inverted case (active_low)
* because of pwm_set_invert function
*/
if (def_brightness < max_brightness)
priv->duty = priv->period * def_brightness / max_brightness;
else
priv->duty = priv->period;
return 0;
}
static int led_pwm_bind(struct udevice *parent)
{
struct udevice *dev;
ofnode node;
int ret;
dev_for_each_subnode(node, parent) {
ret = device_bind_driver_to_node(parent, LEDS_PWM_DRIVER_NAME,
ofnode_get_name(node),
node, &dev);
if (ret)
return ret;
}
return 0;
}
static const struct led_ops led_pwm_ops = {
.set_state = led_pwm_set_state,
.get_state = led_pwm_get_state,
};
static const struct udevice_id led_pwm_ids[] = {
{ .compatible = "pwm-leds" },
{ }
};
U_BOOT_DRIVER(led_pwm) = {
.name = LEDS_PWM_DRIVER_NAME,
.id = UCLASS_LED,
.ops = &led_pwm_ops,
.priv_auto = sizeof(struct led_pwm_priv),
.probe = led_pwm_probe,
.of_to_plat = led_pwm_of_to_plat,
};
U_BOOT_DRIVER(led_pwm_wrap) = {
.name = LEDS_PWM_DRIVER_NAME "_wrap",
.id = UCLASS_NOP,
.of_match = led_pwm_ids,
.bind = led_pwm_bind,
};
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