From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jacek Anaszewski Subject: Re: [PATCH 1/3] leds: Add of_led_get() and led_put() Date: Tue, 25 Aug 2015 15:25:13 +0200 Message-ID: <55DC6CB9.5060301@samsung.com> References: <1440502442-19531-1-git-send-email-tomi.valkeinen@ti.com> <1440502442-19531-2-git-send-email-tomi.valkeinen@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mailout1.w1.samsung.com ([210.118.77.11]:34407 "EHLO mailout1.w1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754183AbbHYNZS (ORCPT ); Tue, 25 Aug 2015 09:25:18 -0400 In-reply-to: <1440502442-19531-2-git-send-email-tomi.valkeinen@ti.com> Sender: linux-leds-owner@vger.kernel.org List-Id: linux-leds@vger.kernel.org To: Tomi Valkeinen Cc: Jingoo Han , Lee Jones , linux-leds@vger.kernel.org, linux-fbdev@vger.kernel.org, Andrew Lunn Hi Tomi, Thanks for the patch. Generally, I'd prefer to add files drivers/leds/of.c and include/linux/of_leds.h and put related functions there. Those functions' names should begin with "of_". Please provide also no-op versions of the functions to address configurations when CONFIG_OF isn't enabled. I have also few comments below. On 08/25/2015 01:34 PM, Tomi Valkeinen wrote: > This patch adds basic support for a kernel driver to get a LED device. > This will be used by the led-backlight driver. > > Only OF version is implemented for now, and the behavior is similar to > PWM's of_pwm_get() and pwm_put(). > > Signed-off-by: Tomi Valkeinen > --- > drivers/leds/led-class.c | 75 ++++++++++++++++++++++++++++++++++++++++++++++++ > include/linux/leds.h | 4 +++ > 2 files changed, 79 insertions(+) > > diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c > index beabfbc6f7cd..0cb4fd7d71d6 100644 > --- a/drivers/leds/led-class.c > +++ b/drivers/leds/led-class.c > @@ -20,6 +20,7 @@ > #include > #include > #include > +#include > #include "leds.h" > > static struct class *leds_class; > @@ -216,6 +217,80 @@ static int led_resume(struct device *dev) > > static SIMPLE_DEV_PM_OPS(leds_class_dev_pm_ops, led_suspend, led_resume); > > +/* find OF node for the given led_cdev */ > +static struct device_node *find_led_of_node(struct led_classdev *led_cdev) > +{ > + struct device *led_dev = led_cdev->dev; > + struct device_node *child; > + > + for_each_child_of_node(led_dev->parent->of_node, child) { > + if (of_property_match_string(child, "label", led_cdev->name) == 0) > + return child; > + } > + > + return NULL; > +} > + > +static int led_match_led_node(struct device *led_dev, const void *data) > +{ > + struct led_classdev *led_cdev = dev_get_drvdata(led_dev); > + const struct device_node *target_node = data; > + struct device_node *led_node; > + > + led_node = find_led_of_node(led_cdev); > + if (!led_node) > + return 0; > + > + of_node_put(led_node); > + > + return led_node == target_node ? 1 : 0; > +} > + > +/** > + * of_led_get() - request a LED device via the LED framework > + * @np: device node to get the LED device from > + * > + * Returns the LED device parsed from the phandle specified in the "leds" > + * property of a device tree node or a negative error-code on failure. > + */ > +struct led_classdev *of_led_get(struct device_node *np) > +{ > + struct device *led_dev; > + struct led_classdev *led_cdev; > + struct device_node *led_node; > + > + led_node = of_parse_phandle(np, "leds", 0); > + if (!led_node) > + return ERR_PTR(-ENODEV); > + > + led_dev = class_find_device(leds_class, NULL, led_node, > + led_match_led_node); Single of_node_put(led_node) here will do. > + if (!led_dev) { > + of_node_put(led_node); > + return ERR_PTR(-EPROBE_DEFER); > + } > + > + of_node_put(led_node); > + led_cdev = dev_get_drvdata(led_dev); > + > + if (!try_module_get(led_cdev->dev->parent->driver->owner)) > + return ERR_PTR(-ENODEV); > + > + return led_cdev; > +} > +EXPORT_SYMBOL_GPL(of_led_get); > +/** > + * led_put() - release a LED device > + * @led_cdev: LED device > + */ > +void led_put(struct led_classdev *led_cdev) > +{ > + module_put(led_cdev->dev->parent->driver->owner); > +} > +EXPORT_SYMBOL_GPL(led_put); Please move it to include/linux/leds.h, make static inline and provide also no-op version for the case when CONFIG_LEDS_CLASS isn't enabled. > static int match_name(struct device *dev, const void *data) > { > if (!dev_name(dev)) > diff --git a/include/linux/leds.h b/include/linux/leds.h > index b122eeafb5dc..efc9b28af564 100644 > --- a/include/linux/leds.h > +++ b/include/linux/leds.h > @@ -21,6 +21,7 @@ > #include > > struct device; > +struct device_node; > /* > * LED Core > */ > @@ -113,6 +114,9 @@ extern void devm_led_classdev_unregister(struct device *parent, > extern void led_classdev_suspend(struct led_classdev *led_cdev); > extern void led_classdev_resume(struct led_classdev *led_cdev); > > +extern struct led_classdev *of_led_get(struct device_node *np); We need also no-op version for (!CONFIG_OF || !CONFIG_LEDS_CLASS). > +extern void led_put(struct led_classdev *led_cdev); > + > /** > * led_blink_set - set blinking with software fallback > * @led_cdev: the LED to start blinking > -- Best Regards, Jacek Anaszewski