From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hans de Goede Subject: [PATCH v5 3/6] leds: triggers: Add support for read-only triggers Date: Thu, 17 Nov 2016 23:24:38 +0100 Message-ID: <20161117222441.31464-3-hdegoede@redhat.com> References: <20161117222441.31464-1-hdegoede@redhat.com> Return-path: Received: from mx1.redhat.com ([209.132.183.28]:60098 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752190AbcKQWYu (ORCPT ); Thu, 17 Nov 2016 17:24:50 -0500 In-Reply-To: <20161117222441.31464-1-hdegoede@redhat.com> Sender: linux-leds-owner@vger.kernel.org List-Id: linux-leds@vger.kernel.org To: Darren Hart , Matthew Garrett , =?UTF-8?q?Pali=20Roh=C3=A1r?= , Henrique de Moraes Holschuh , Richard Purdie , Jacek Anaszewski Cc: ibm-acpi-devel@lists.sourceforge.net, platform-driver-x86@vger.kernel.org, linux-leds@vger.kernel.org, Hans de Goede In some cases an LED is controlled through a hardwired (taken care of in firmware outside of the kernels control) trigger. Add an LED_TRIGGER_READ_ONLY flag for this and disallow user-space changing the trigger when this flag is set. Signed-off-by: Hans de Goede --- Changes in v5: -This is a new patch in v5 of this patch-set --- drivers/leds/led-class.c | 2 +- drivers/leds/led-triggers.c | 5 +++++ include/linux/leds.h | 1 + 3 files changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c index 326ee6e..56f32cc 100644 --- a/drivers/leds/led-class.c +++ b/drivers/leds/led-class.c @@ -54,7 +54,7 @@ static ssize_t brightness_store(struct device *dev, if (ret) goto unlock; - if (state == LED_OFF) + if (state == LED_OFF && !(led_cdev->flags & LED_TRIGGER_READ_ONLY)) led_trigger_remove(led_cdev); led_set_brightness(led_cdev, state); diff --git a/drivers/leds/led-triggers.c b/drivers/leds/led-triggers.c index d2ed9c2..9669104 100644 --- a/drivers/leds/led-triggers.c +++ b/drivers/leds/led-triggers.c @@ -37,6 +37,11 @@ ssize_t led_trigger_store(struct device *dev, struct device_attribute *attr, struct led_trigger *trig; int ret = count; + if (led_cdev->flags & LED_TRIGGER_READ_ONLY) { + dev_err(led_cdev->dev, "Error this led triggers is hardwired and cannot be changed\n"); + return -EINVAL; + } + mutex_lock(&led_cdev->led_access); if (led_sysfs_is_disabled(led_cdev)) { diff --git a/include/linux/leds.h b/include/linux/leds.h index 870b8c2..e076b74 100644 --- a/include/linux/leds.h +++ b/include/linux/leds.h @@ -47,6 +47,7 @@ struct led_classdev { #define LED_DEV_CAP_FLASH (1 << 18) #define LED_HW_PLUGGABLE (1 << 19) #define LED_PANIC_INDICATOR (1 << 20) +#define LED_TRIGGER_READ_ONLY (1 << 21) /* set_brightness_work / blink_timer flags, atomic, private. */ unsigned long work_flags; -- 2.9.3