From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jacek Anaszewski Subject: Re: [PATCH 02/24] leds: core: Add support for composing LED class device names Date: Thu, 8 Nov 2018 21:48:04 +0100 Message-ID: <5e857610-baee-9b4b-7a21-025be1f9670e@gmail.com> References: <1541542052-10081-1-git-send-email-jacek.anaszewski@gmail.com> <1541542052-10081-3-git-send-email-jacek.anaszewski@gmail.com> <84dd8750-883e-1318-df85-f4c6b46b898f@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <84dd8750-883e-1318-df85-f4c6b46b898f@ti.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Dan Murphy , linux-leds@vger.kernel.org Cc: devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, pavel@ucw.cz, robh@kernel.org, Baolin Wang , Daniel Mack , Linus Walleij , Oleh Kravchenko , Sakari Ailus , Simon Shields , Xiaotong Lu List-Id: linux-leds@vger.kernel.org Dan, On 11/08/2018 07:06 PM, Dan Murphy wrote: > On 11/06/2018 04:07 PM, Jacek Anaszewski wrote: >> 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 we have the label do we need to continue to look for the function and color nodes? > > It can be checked and diverted using fwnode_property_present for the "label" property Good catch. I will respin it as proposed. >> + 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 > > s/aforementioned > >> + * 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, >> > > -- Best regards, Jacek Anaszewski