forked from Minki/linux
leds: leds-pwm: Add device tree bindings
The DT binding for the pwm-leds devices are similar to the gpio-leds type. LEDs are represented as sub-nodes of the pwm-leds device. The code for handling the DT boot is based on the code found in the leds-gpio driver and adapted to use PWMs instead of GPIOs. To avoid having custom cleanup code in case of DT boot the newly created devm_of_pwm_get() API is used to get the correct PWM instance. For usage see: Documentation/devicetree/bindings/leds/leds-pwm.txt Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Acked-by: Grant Likely <grant.likely@secretlab.ca> Signed-off-by: Bryan Wu <cooloney@gmail.com>
This commit is contained in:
Peter Ujfalusi
Bryan Wu
parent
8a66a57908
commit
08541cbcc7
48
Documentation/devicetree/bindings/leds/leds-pwm.txt
Normal file
48
Documentation/devicetree/bindings/leds/leds-pwm.txt
Normal file
@ -0,0 +1,48 @@
|
||||
LED connected to PWM
|
||||
|
||||
Required properties:
|
||||
- compatible : should be "pwm-leds".
|
||||
|
||||
Each LED is represented as a sub-node of the pwm-leds device. Each
|
||||
node's name represents the name of the corresponding LED.
|
||||
|
||||
LED sub-node properties:
|
||||
- pwms : PWM property to point to the PWM device (phandle)/port (id) and to
|
||||
specify the period time to be used: <&phandle id period_ns>;
|
||||
- pwm-names : (optional) Name to be used by the PWM subsystem for the PWM device
|
||||
For the pwms and pwm-names property please refer to:
|
||||
Documentation/devicetree/bindings/pwm/pwm.txt
|
||||
- max-brightness : Maximum brightness possible for the LED
|
||||
- label : (optional)
|
||||
see Documentation/devicetree/bindings/leds/common.txt
|
||||
- linux,default-trigger : (optional)
|
||||
see Documentation/devicetree/bindings/leds/common.txt
|
||||
|
||||
Example:
|
||||
|
||||
twl_pwm: pwm {
|
||||
/* provides two PWMs (id 0, 1 for PWM1 and PWM2) */
|
||||
compatible = "ti,twl6030-pwm";
|
||||
#pwm-cells = <2>;
|
||||
};
|
||||
|
||||
twl_pwmled: pwmled {
|
||||
/* provides one PWM (id 0 for Charing indicator LED) */
|
||||
compatible = "ti,twl6030-pwmled";
|
||||
#pwm-cells = <2>;
|
||||
};
|
||||
|
||||
pwmleds {
|
||||
compatible = "pwm-leds";
|
||||
kpad {
|
||||
label = "omap4::keypad";
|
||||
pwms = <&twl_pwm 0 7812500>;
|
||||
max-brightness = <127>;
|
||||
};
|
||||
|
||||
charging {
|
||||
label = "omap4:green:chrg";
|
||||
pwms = <&twl_pwmled 0 7812500>;
|
||||
max-brightness = <255>;
|
||||
};
|
||||
};
|
||||
@ -16,6 +16,7 @@
|
||||
#include <linux/kernel.h>
|
||||
#include <linux/init.h>
|
||||
#include <linux/platform_device.h>
|
||||
#include <linux/of_platform.h>
|
||||
#include <linux/fb.h>
|
||||
#include <linux/leds.h>
|
||||
#include <linux/err.h>
|
||||
@ -58,46 +59,110 @@ static inline size_t sizeof_pwm_leds_priv(int num_leds)
|
||||
(sizeof(struct led_pwm_data) * num_leds);
|
||||
}
|
||||
|
||||
static struct led_pwm_priv *led_pwm_create_of(struct platform_device *pdev)
|
||||
{
|
||||
struct device_node *node = pdev->dev.of_node;
|
||||
struct device_node *child;
|
||||
struct led_pwm_priv *priv;
|
||||
int count, ret;
|
||||
|
||||
/* count LEDs in this device, so we know how much to allocate */
|
||||
count = of_get_child_count(node);
|
||||
if (!count)
|
||||
return NULL;
|
||||
|
||||
priv = devm_kzalloc(&pdev->dev, sizeof_pwm_leds_priv(count),
|
||||
GFP_KERNEL);
|
||||
if (!priv)
|
||||
return NULL;
|
||||
|
||||
for_each_child_of_node(node, child) {
|
||||
struct led_pwm_data *led_dat = &priv->leds[priv->num_leds];
|
||||
|
||||
led_dat->cdev.name = of_get_property(child, "label",
|
||||
NULL) ? : child->name;
|
||||
|
||||
led_dat->pwm = devm_of_pwm_get(&pdev->dev, child, NULL);
|
||||
if (IS_ERR(led_dat->pwm)) {
|
||||
dev_err(&pdev->dev, "unable to request PWM for %s\n",
|
||||
led_dat->cdev.name);
|
||||
goto err;
|
||||
}
|
||||
/* Get the period from PWM core when n*/
|
||||
led_dat->period = pwm_get_period(led_dat->pwm);
|
||||
|
||||
led_dat->cdev.default_trigger = of_get_property(child,
|
||||
"linux,default-trigger", NULL);
|
||||
of_property_read_u32(child, "max-brightness",
|
||||
&led_dat->cdev.max_brightness);
|
||||
|
||||
led_dat->cdev.brightness_set = led_pwm_set;
|
||||
led_dat->cdev.brightness = LED_OFF;
|
||||
led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
|
||||
|
||||
ret = led_classdev_register(&pdev->dev, &led_dat->cdev);
|
||||
if (ret < 0) {
|
||||
dev_err(&pdev->dev, "failed to register for %s\n",
|
||||
led_dat->cdev.name);
|
||||
of_node_put(child);
|
||||
goto err;
|
||||
}
|
||||
priv->num_leds++;
|
||||
}
|
||||
|
||||
return priv;
|
||||
err:
|
||||
while (priv->num_leds--)
|
||||
led_classdev_unregister(&priv->leds[priv->num_leds].cdev);
|
||||
|
||||
return NULL;
|
||||
}
|
||||
|
||||
static int led_pwm_probe(struct platform_device *pdev)
|
||||
{
|
||||
struct led_pwm_platform_data *pdata = pdev->dev.platform_data;
|
||||
struct led_pwm_priv *priv;
|
||||
int i, ret = 0;
|
||||
|
||||
if (!pdata)
|
||||
return -EBUSY;
|
||||
if (pdata && pdata->num_leds) {
|
||||
priv = devm_kzalloc(&pdev->dev,
|
||||
sizeof_pwm_leds_priv(pdata->num_leds),
|
||||
GFP_KERNEL);
|
||||
if (!priv)
|
||||
return -ENOMEM;
|
||||
|
||||
priv = devm_kzalloc(&pdev->dev, sizeof_pwm_leds_priv(pdata->num_leds),
|
||||
GFP_KERNEL);
|
||||
if (!priv)
|
||||
return -ENOMEM;
|
||||
for (i = 0; i < pdata->num_leds; i++) {
|
||||
struct led_pwm *cur_led = &pdata->leds[i];
|
||||
struct led_pwm_data *led_dat = &priv->leds[i];
|
||||
|
||||
for (i = 0; i < pdata->num_leds; i++) {
|
||||
struct led_pwm *cur_led = &pdata->leds[i];
|
||||
struct led_pwm_data *led_dat = &priv->leds[i];
|
||||
led_dat->pwm = devm_pwm_get(&pdev->dev, cur_led->name);
|
||||
if (IS_ERR(led_dat->pwm)) {
|
||||
ret = PTR_ERR(led_dat->pwm);
|
||||
dev_err(&pdev->dev,
|
||||
"unable to request PWM for %s\n",
|
||||
cur_led->name);
|
||||
goto err;
|
||||
}
|
||||
|
||||
led_dat->pwm = devm_pwm_get(&pdev->dev, cur_led->name);
|
||||
if (IS_ERR(led_dat->pwm)) {
|
||||
ret = PTR_ERR(led_dat->pwm);
|
||||
dev_err(&pdev->dev, "unable to request PWM for %s\n",
|
||||
cur_led->name);
|
||||
goto err;
|
||||
led_dat->cdev.name = cur_led->name;
|
||||
led_dat->cdev.default_trigger = cur_led->default_trigger;
|
||||
led_dat->active_low = cur_led->active_low;
|
||||
led_dat->period = cur_led->pwm_period_ns;
|
||||
led_dat->cdev.brightness_set = led_pwm_set;
|
||||
led_dat->cdev.brightness = LED_OFF;
|
||||
led_dat->cdev.max_brightness = cur_led->max_brightness;
|
||||
led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
|
||||
|
||||
ret = led_classdev_register(&pdev->dev, &led_dat->cdev);
|
||||
if (ret < 0)
|
||||
goto err;
|
||||
}
|
||||
|
||||
led_dat->cdev.name = cur_led->name;
|
||||
led_dat->cdev.default_trigger = cur_led->default_trigger;
|
||||
led_dat->active_low = cur_led->active_low;
|
||||
led_dat->period = cur_led->pwm_period_ns;
|
||||
led_dat->cdev.brightness_set = led_pwm_set;
|
||||
led_dat->cdev.brightness = LED_OFF;
|
||||
led_dat->cdev.max_brightness = cur_led->max_brightness;
|
||||
led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
|
||||
|
||||
ret = led_classdev_register(&pdev->dev, &led_dat->cdev);
|
||||
if (ret < 0)
|
||||
goto err;
|
||||
priv->num_leds = pdata->num_leds;
|
||||
} else {
|
||||
priv = led_pwm_create_of(pdev);
|
||||
if (!priv)
|
||||
return -ENODEV;
|
||||
}
|
||||
priv->num_leds = pdata->num_leds;
|
||||
|
||||
platform_set_drvdata(pdev, priv);
|
||||
|
||||
@ -121,12 +186,19 @@ static int led_pwm_remove(struct platform_device *pdev)
|
||||
return 0;
|
||||
}
|
||||
|
||||
static const struct of_device_id of_pwm_leds_match[] = {
|
||||
{ .compatible = "pwm-leds", },
|
||||
{},
|
||||
};
|
||||
MODULE_DEVICE_TABLE(of, of_pwm_leds_match);
|
||||
|
||||
static struct platform_driver led_pwm_driver = {
|
||||
.probe = led_pwm_probe,
|
||||
.remove = led_pwm_remove,
|
||||
.driver = {
|
||||
.name = "leds_pwm",
|
||||
.owner = THIS_MODULE,
|
||||
.of_match_table = of_match_ptr(of_pwm_leds_match),
|
||||
},
|
||||
};
|
||||
|
||||
|
||||
Loading…
Reference in New Issue
Block a user