From 08541cbcc7386fa78efb454a92ddbfb1a2859cf9 Mon Sep 17 00:00:00 2001 From: Peter Ujfalusi Date: Fri, 21 Dec 2012 01:44:01 -0800 Subject: [PATCH] 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 Acked-by: Grant Likely Signed-off-by: Bryan Wu --- .../devicetree/bindings/leds/leds-pwm.txt | 48 ++++++++ drivers/leds/leds-pwm.c | 112 ++++++++++++++---- 2 files changed, 140 insertions(+), 20 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 000000000000..7297107cf832 --- /dev/null +++ b/Documentation/devicetree/bindings/leds/leds-pwm.txt @@ -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>; + }; +}; diff --git a/drivers/leds/leds-pwm.c b/drivers/leds/leds-pwm.c index 46f4e44c6c6d..a1ea5f6a8d39 100644 --- a/drivers/leds/leds-pwm.c +++ b/drivers/leds/leds-pwm.c @@ -16,6 +16,7 @@ #include #include #include +#include #include #include #include @@ -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), }, }; -- 2.34.1