From patchwork Tue Sep 8 11:19:34 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tomi Valkeinen X-Patchwork-Id: 7140181 Return-Path: X-Original-To: patchwork-linux-fbdev@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 861D4BEEC1 for ; Tue, 8 Sep 2015 11:20:05 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 52337206E4 for ; Tue, 8 Sep 2015 11:20:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1EAD9206E0 for ; Tue, 8 Sep 2015 11:20:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754120AbbIHLT7 (ORCPT ); Tue, 8 Sep 2015 07:19:59 -0400 Received: from devils.ext.ti.com ([198.47.26.153]:45354 "EHLO devils.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754089AbbIHLT6 (ORCPT ); Tue, 8 Sep 2015 07:19:58 -0400 Received: from dflxv15.itg.ti.com ([128.247.5.124]) by devils.ext.ti.com (8.13.7/8.13.7) with ESMTP id t88BJl53021934; Tue, 8 Sep 2015 06:19:47 -0500 Received: from DLEE71.ent.ti.com (dlee71.ent.ti.com [157.170.170.114]) by dflxv15.itg.ti.com (8.14.3/8.13.8) with ESMTP id t88BJkaL027157; Tue, 8 Sep 2015 06:19:47 -0500 Received: from dflp33.itg.ti.com (10.64.6.16) by DLEE71.ent.ti.com (157.170.170.114) with Microsoft SMTP Server id 14.3.224.2; Tue, 8 Sep 2015 06:19:40 -0500 Received: from deskari.ti.com (ileax41-snat.itg.ti.com [10.172.224.153]) by dflp33.itg.ti.com (8.14.3/8.13.8) with ESMTP id t88BJgpF018809; Tue, 8 Sep 2015 06:19:45 -0500 From: Tomi Valkeinen To: Jacek Anaszewski , Jingoo Han , Lee Jones , , CC: Andrew Lunn , Tomi Valkeinen Subject: [PATCHv2 1/3] leds: Add of_led_get() and led_put() Date: Tue, 8 Sep 2015 14:19:34 +0300 Message-ID: <1441711176-4258-2-git-send-email-tomi.valkeinen@ti.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1441711176-4258-1-git-send-email-tomi.valkeinen@ti.com> References: <1441711176-4258-1-git-send-email-tomi.valkeinen@ti.com> MIME-Version: 1.0 Sender: linux-fbdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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/Makefile | 6 +++- drivers/leds/led-class.c | 13 +++++++- drivers/leds/led-of.c | 82 ++++++++++++++++++++++++++++++++++++++++++++++++ drivers/leds/leds.h | 1 + include/linux/leds-of.h | 26 +++++++++++++++ include/linux/leds.h | 2 ++ 6 files changed, 128 insertions(+), 2 deletions(-) create mode 100644 drivers/leds/led-of.c create mode 100644 include/linux/leds-of.h diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile index 8d6a24a2f513..6fd22e411810 100644 --- a/drivers/leds/Makefile +++ b/drivers/leds/Makefile @@ -1,7 +1,11 @@ # LED Core obj-$(CONFIG_NEW_LEDS) += led-core.o -obj-$(CONFIG_LEDS_CLASS) += led-class.o + +obj-$(CONFIG_LEDS_CLASS) += led-class-objs.o +led-class-objs-y := led-class.o +led-class-objs-$(CONFIG_OF) += led-of.o + obj-$(CONFIG_LEDS_CLASS_FLASH) += led-class-flash.o obj-$(CONFIG_LEDS_TRIGGERS) += led-triggers.o diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c index beabfbc6f7cd..1234f9dc3537 100644 --- a/drivers/leds/led-class.c +++ b/drivers/leds/led-class.c @@ -22,7 +22,7 @@ #include #include "leds.h" -static struct class *leds_class; +struct class *leds_class; static ssize_t brightness_show(struct device *dev, struct device_attribute *attr, char *buf) @@ -216,6 +216,17 @@ static int led_resume(struct device *dev) static SIMPLE_DEV_PM_OPS(leds_class_dev_pm_ops, led_suspend, led_resume); +/** + * led_put() - release a LED device, reserved with led_get() + * @led_cdev: LED device + */ +void led_put(struct led_classdev *led_cdev) +{ + put_device(led_cdev->dev); + module_put(led_cdev->dev->parent->driver->owner); +} +EXPORT_SYMBOL_GPL(led_put); + static int match_name(struct device *dev, const void *data) { if (!dev_name(dev)) diff --git a/drivers/leds/led-of.c b/drivers/leds/led-of.c new file mode 100644 index 000000000000..32631682be07 --- /dev/null +++ b/drivers/leds/led-of.c @@ -0,0 +1,82 @@ +/* + * LED Class Core OF support + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include +#include +#include +#include + +#include "leds.h" + +/* 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. + * + * The caller must use led_put() to release the device after use. + */ +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); + + of_node_put(led_node); + + if (!led_dev) { + pr_err("failed to find led device for node %s, deferring probe\n", + of_node_full_name(led_node)); + return ERR_PTR(-EPROBE_DEFER); + } + + 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); diff --git a/drivers/leds/leds.h b/drivers/leds/leds.h index bc89d7ace2c4..ccc3abb417d4 100644 --- a/drivers/leds/leds.h +++ b/drivers/leds/leds.h @@ -46,6 +46,7 @@ static inline int led_get_brightness(struct led_classdev *led_cdev) void led_stop_software_blink(struct led_classdev *led_cdev); +extern struct class *leds_class; extern struct rw_semaphore leds_list_lock; extern struct list_head leds_list; diff --git a/include/linux/leds-of.h b/include/linux/leds-of.h new file mode 100644 index 000000000000..7e8e64bd9811 --- /dev/null +++ b/include/linux/leds-of.h @@ -0,0 +1,26 @@ +/* + * OF support for leds + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + */ + +#ifndef __LINUX_LEDS_OF_H_INCLUDED +#define __LINUX_LEDS_OF_H_INCLUDED + +#if IS_ENABLED(CONFIG_OF) && IS_ENABLED(CONFIG_LEDS_CLASS) + +extern struct led_classdev *of_led_get(struct device_node *np); + +#else + +static inline struct led_classdev *of_led_get(struct device_node *np) +{ + return -ENODEV; +} + +#endif + +#endif /* __LINUX_LEDS_OF_H_INCLUDED */ diff --git a/include/linux/leds.h b/include/linux/leds.h index b122eeafb5dc..0fce71a06d68 100644 --- a/include/linux/leds.h +++ b/include/linux/leds.h @@ -113,6 +113,8 @@ 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 void led_put(struct led_classdev *led_cdev); + /** * led_blink_set - set blinking with software fallback * @led_cdev: the LED to start blinking