Support for device tree booted kernel. When the kernel is booted with DeviceTree blob we support one led per leds-pwm device to have cleaner integration with the PWM subsystem.
For usage see: Documentation/devicetree/bindings/leds/leds-pwm.txt Signed-off-by: Peter Ujfalusi <[email protected]> --- .../devicetree/bindings/leds/leds-pwm.txt | 34 ++++++ drivers/leds/leds-pwm.c | 125 +++++++++++++++------ 2 files changed, 127 insertions(+), 32 deletions(-) create mode 100644 Documentation/devicetree/bindings/leds/leds-pwm.txt diff --git a/Documentation/devicetree/bindings/leds/leds-pwm.txt b/Documentation/devicetree/bindings/leds/leds-pwm.txt new file mode 100644 index 0000000..9fe3040 --- /dev/null +++ b/Documentation/devicetree/bindings/leds/leds-pwm.txt @@ -0,0 +1,34 @@ +LED connected to PWM + +Required properties: +- compatible : should be "pwm-leds". +- pwms : PWM property, please refer to: + Documentation/devicetree/bindings/pwm/pwm.txt +- pwm-names : (optional) Name to be used by the PWM subsystem for the PWM device +- label : (optional) The label for this LED. If omitted, the label is + taken from the node name (excluding the unit address). +- max-brightness : Maximum brightness possible for the LED +- linux,default-trigger : (optional) This parameter, if present, is a + string defining the trigger assigned to the LED. Current triggers are: + "backlight" - LED will act as a back-light, controlled by the framebuffer + system + "default-on" - LED will turn on, but see "default-state" below + "heartbeat" - LED "double" flashes at a load average based rate + "ide-disk" - LED indicates disk activity + "timer" - LED flashes at a fixed, configurable rate + +Example: + +twl_pwm: pwm { + compatible = "ti,twl6030-pwm"; + #pwm-cells = <2>; +}; + +pwmled_keypad { + compatible = "pwm-leds"; + pwms = <&twl_pwm 0 7812500>; + pwm-names = "Keypad LED"; + + label = "omap4::keypad"; + max-brightness = <127>; +}; diff --git a/drivers/leds/leds-pwm.c b/drivers/leds/leds-pwm.c index b219ea9..333c942 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 +59,98 @@ static inline int 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 led_pwm_priv *priv; + struct led_pwm_data *led_dat; + int ret; + + /* With DT boot we support one LED per leds-pwm device */ + priv = devm_kzalloc(&pdev->dev, sizeof_pwm_leds_priv(1), + GFP_KERNEL); + if (!priv) + return NULL; + + led_dat = &priv->leds[priv->num_leds]; + led_dat->cdev.name = of_get_property(node, "label", NULL) ? : node->name; + led_dat->pwm = devm_pwm_get(&pdev->dev, NULL); + if (IS_ERR(led_dat->pwm)) { + dev_err(&pdev->dev, "unable to request PWM for %s\n", + led_dat->cdev.name); + return NULL; + } + /* 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(node, + "linux,default-trigger", + NULL); + of_property_read_u32(node, "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(node); + return NULL; + } + + priv->num_leds = 1; + + return priv; +} + 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; - - 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; + 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; } - - 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); @@ -123,12 +176,20 @@ static int __devexit 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 = __devexit_p(led_pwm_remove), .driver = { .name = "leds_pwm", .owner = THIS_MODULE, + .of_match_table = of_match_ptr(of_pwm_leds_match), }, }; -- 1.8.0 _______________________________________________ devicetree-discuss mailing list [email protected] https://lists.ozlabs.org/listinfo/devicetree-discuss
