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author | Peter Ujfalusi <peter.ujfalusi@ti.com> | 2012-12-21 01:44:01 -0800 |
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committer | Bryan Wu <cooloney@gmail.com> | 2013-02-01 17:47:05 -0800 |
commit | 08541cbcc7386fa78efb454a92ddbfb1a2859cf9 (patch) | |
tree | 288c9a3b4fcd689cb4551999afa39dbfa2fd0ee2 /drivers | |
parent | 8a66a579083a20172a46e74d175a57621dccae0a (diff) | |
download | op-kernel-dev-08541cbcc7386fa78efb454a92ddbfb1a2859cf9.zip op-kernel-dev-08541cbcc7386fa78efb454a92ddbfb1a2859cf9.tar.gz |
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>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/leds/leds-pwm.c | 112 |
1 files changed, 92 insertions, 20 deletions
diff --git a/drivers/leds/leds-pwm.c b/drivers/leds/leds-pwm.c index 46f4e44..a1ea5f6 100644 --- a/drivers/leds/leds-pwm.c +++ b/drivers/leds/leds-pwm.c @@ -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 int led_pwm_probe(struct platform_device *pdev) +static struct led_pwm_priv *led_pwm_create_of(struct platform_device *pdev) { - struct led_pwm_platform_data *pdata = pdev->dev.platform_data; + struct device_node *node = pdev->dev.of_node; + struct device_node *child; struct led_pwm_priv *priv; - int i, ret = 0; + int count, ret; - if (!pdata) - return -EBUSY; + /* 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(pdata->num_leds), + priv = devm_kzalloc(&pdev->dev, sizeof_pwm_leds_priv(count), GFP_KERNEL); if (!priv) - return -ENOMEM; + return NULL; - 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_each_child_of_node(node, child) { + struct led_pwm_data *led_dat = &priv->leds[priv->num_leds]; - led_dat->pwm = devm_pwm_get(&pdev->dev, cur_led->name); + 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)) { - ret = PTR_ERR(led_dat->pwm); dev_err(&pdev->dev, "unable to request PWM for %s\n", - cur_led->name); + 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.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) + 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 && pdata->num_leds) { + 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]; + + 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; + } + 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), }, }; |