From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jacek Anaszewski Subject: [PATCH 02/24] leds: core: Add support for composing LED class device names Date: Tue, 6 Nov 2018 23:07:10 +0100 Message-ID: <1541542052-10081-3-git-send-email-jacek.anaszewski@gmail.com> References: <1541542052-10081-1-git-send-email-jacek.anaszewski@gmail.com> Return-path: In-Reply-To: <1541542052-10081-1-git-send-email-jacek.anaszewski@gmail.com> Sender: linux-kernel-owner@vger.kernel.org To: linux-leds@vger.kernel.org Cc: devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, pavel@ucw.cz, robh@kernel.org, jacek.anaszewski@gmail.com, Baolin Wang , Daniel Mack , Dan Murphy , Linus Walleij , Oleh Kravchenko , Sakari Ailus , Simon Shields , Xiaotong Lu List-Id: linux-leds@vger.kernel.org Add public led_compose_name() API for composing LED class device name basing on fwnode_handle data. The function composes device name according to either a new pattern or the legacy pattern. The decision on using the particular pattern is made basing on whether fwnode contains new "function" and "color" properties, or the legacy "label" proeprty. Backwards compatibility with in-driver hard-coded LED class device names is assured thanks to the default_desc argument. In case none of the aformentioned properties was found, then, for OF nodes, the node name is adopted for LED class device name. Signed-off-by: Jacek Anaszewski Cc: Baolin Wang Cc: Daniel Mack Cc: Dan Murphy Cc: Linus Walleij Cc: Oleh Kravchenko Cc: Sakari Ailus Cc: Simon Shields Cc: Xiaotong Lu --- Documentation/leds/leds-class.txt | 2 +- drivers/leds/led-core.c | 71 +++++++++++++++++++++++++++++++++++++++ include/linux/leds.h | 32 ++++++++++++++++++ 3 files changed, 104 insertions(+), 1 deletion(-) diff --git a/Documentation/leds/leds-class.txt b/Documentation/leds/leds-class.txt index 836cb16..e9009c4 100644 --- a/Documentation/leds/leds-class.txt +++ b/Documentation/leds/leds-class.txt @@ -43,7 +43,7 @@ LED Device Naming Is currently of the form: -"devicename:colour:function" +"colour:function" There have been calls for LED properties such as colour to be exported as individual led class attributes. As a solution which doesn't incur as much diff --git a/drivers/leds/led-core.c b/drivers/leds/led-core.c index ede4fa0..f7371fc 100644 --- a/drivers/leds/led-core.c +++ b/drivers/leds/led-core.c @@ -16,6 +16,8 @@ #include #include #include +#include +#include #include #include "leds.h" @@ -327,3 +329,72 @@ void led_sysfs_enable(struct led_classdev *led_cdev) led_cdev->flags &= ~LED_SYSFS_DISABLE; } EXPORT_SYMBOL_GPL(led_sysfs_enable); + +static void led_parse_properties(struct fwnode_handle *fwnode, + struct led_properties *props) +{ + int ret; + + if (!fwnode) + return; + + ret = fwnode_property_read_string(fwnode, "label", &props->label); + if (!ret) + return; + + ret = fwnode_property_read_string(fwnode, "function", &props->function); + if (ret) + pr_info("Failed to parse function property\n"); + + ret = fwnode_property_read_string(fwnode, "color", &props->color); + if (ret) + pr_info("Failed to parse color property\n"); +} + +int led_compose_name(struct fwnode_handle *fwnode, const char *led_hw_name, + const char *default_desc, char *led_classdev_name) +{ + struct led_properties props = {}; + + if (!led_classdev_name) + return -EINVAL; + + led_parse_properties(fwnode, &props); + + if (props.label) { + /* + * Presence of 'label' DT property implies legacy LED name, + * formatted as , with possible + * section omission if doesn't apply to given device. + * + * If no led_hw_name has been passed, then it indicates that + * DT label should be used as-is for LED class device name. + * Otherwise the label is prepended with led_hw_name to compose + * the final LED class device name. + */ + if (!led_hw_name) { + strncpy(led_classdev_name, props.label, + LED_MAX_NAME_SIZE); + } else { + snprintf(led_classdev_name, LED_MAX_NAME_SIZE, "%s:%s", + led_hw_name, props.label); + } + } else if (props.function || props.color) { + snprintf(led_classdev_name, LED_MAX_NAME_SIZE, "%s:%s", + props.color ?: "", props.function ?: ""); + } else if (default_desc) { + if (!led_hw_name) { + pr_err("Legacy LED naming requires devicename segment"); + return -EINVAL; + } + snprintf(led_classdev_name, LED_MAX_NAME_SIZE, "%s:%s", + led_hw_name, default_desc); + } else if (is_of_node(fwnode)) { + strncpy(led_classdev_name, to_of_node(fwnode)->name, + LED_MAX_NAME_SIZE); + } else + return -EINVAL; + + return 0; +} +EXPORT_SYMBOL_GPL(led_compose_name); diff --git a/include/linux/leds.h b/include/linux/leds.h index 646c49a..ddb4001 100644 --- a/include/linux/leds.h +++ b/include/linux/leds.h @@ -238,6 +238,32 @@ extern void led_sysfs_disable(struct led_classdev *led_cdev); extern void led_sysfs_enable(struct led_classdev *led_cdev); /** + * led_compose_name - compose LED class device name + * @child: child fwnode_handle describing a LED, + * or a group of synchronized LEDs. + * @led_hw_name: name of the LED controller, used when falling back to legacy + * LED naming; it should be set to NULL in new LED class drivers + * @default_desc: default tuple, for backwards compatibility + * with in-driver hard-coded LED names used as a fallback when + * "label" DT property was absent; it should be set to NULL + * in new LED class drivers + * @led_classdev_name: composed LED class device name + * + * Create LED class device name basing on the configuration provided by the + * board firmware. The name can have a legacy form , + * or a new form . The latter is chosen if at least one of + * "color" or "function" properties is present in the fwnode, leaving the + * section blank if the related property is absent. The former is applied + * when legacy "label" property is present in the fwnode. In case none of the + * aformentioned properties was found, then, for OF nodes, the node name + * is adopted for LED class device name. + * + * Returns: 0 on success or negative error value on failure + */ +extern int led_compose_name(struct fwnode_handle *child, const char *led_hw_name, + const char *default_desc, char *led_classdev_name); + +/** * led_sysfs_is_disabled - check if LED sysfs interface is disabled * @led_cdev: the LED to query * @@ -414,6 +440,12 @@ struct led_platform_data { struct led_info *leds; }; +struct led_properties { + const char *color; + const char *function; + const char *label; +}; + struct gpio_desc; typedef int (*gpio_blink_set_t)(struct gpio_desc *desc, int state, unsigned long *delay_on, -- 2.1.4