From patchwork Tue Aug 25 11:34:00 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tomi Valkeinen X-Patchwork-Id: 7070891 Return-Path: X-Original-To: patchwork-linux-fbdev@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 9FFC49F374 for ; Tue, 25 Aug 2015 11:34:25 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id B0F9120882 for ; Tue, 25 Aug 2015 11:34:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5047F20884 for ; Tue, 25 Aug 2015 11:34:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755512AbbHYLeW (ORCPT ); Tue, 25 Aug 2015 07:34:22 -0400 Received: from devils.ext.ti.com ([198.47.26.153]:59195 "EHLO devils.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751935AbbHYLeV (ORCPT ); Tue, 25 Aug 2015 07:34:21 -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 t7PBYAj0010809; Tue, 25 Aug 2015 06:34:10 -0500 Received: from DFLE72.ent.ti.com (dfle72.ent.ti.com [128.247.5.109]) by dflxv15.itg.ti.com (8.14.3/8.13.8) with ESMTP id t7PBYAb6023588; Tue, 25 Aug 2015 06:34:10 -0500 Received: from dlep32.itg.ti.com (157.170.170.100) by DFLE72.ent.ti.com (128.247.5.109) with Microsoft SMTP Server id 14.3.224.2; Tue, 25 Aug 2015 06:34:10 -0500 Received: from deskari.ti.com (ileax41-snat.itg.ti.com [10.172.224.153]) by dlep32.itg.ti.com (8.14.3/8.13.8) with ESMTP id t7PBY5as032677; Tue, 25 Aug 2015 06:34:08 -0500 From: Tomi Valkeinen To: Jacek Anaszewski , Jingoo Han , Lee Jones , , CC: Andrew Lunn , Tomi Valkeinen Subject: [PATCH 1/3] leds: Add of_led_get() and led_put() Date: Tue, 25 Aug 2015 14:34:00 +0300 Message-ID: <1440502442-19531-2-git-send-email-tomi.valkeinen@ti.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1440502442-19531-1-git-send-email-tomi.valkeinen@ti.com> References: <1440502442-19531-1-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=-8.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, 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/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); + 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); + 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); +extern void led_put(struct led_classdev *led_cdev); + /** * led_blink_set - set blinking with software fallback * @led_cdev: the LED to start blinking