/sys/class/leds/<led>/add_blkdev - to create device/LED associations /sys/class/leds/<led>/delete_blkdev to remove device/LED associations For both attributes, accept multiple device names separated by whitespace Signed-off-by: Ian Pilcher <arequipeno@gmail.com> --- drivers/leds/trigger/ledtrig-blkdev.c | 48 +++++++++++++++++++++++++++ 1 file changed, 48 insertions(+) diff --git a/drivers/leds/trigger/ledtrig-blkdev.c b/drivers/leds/trigger/ledtrig-blkdev.c index a1646752b9a0..15b15aefdfd8 100644 --- a/drivers/leds/trigger/ledtrig-blkdev.c +++ b/drivers/leds/trigger/ledtrig-blkdev.c @@ -480,3 +480,51 @@ static int blkdev_disk_add(struct ledtrig_blkdev_led *const led, exit_return: return ret; } + + +/* + * + * sysfs attributes to add & delete devices from LEDs + * + */ + +static ssize_t blkdev_add_or_del(struct device *const dev, + struct device_attribute *const attr, + const char *const buf, const size_t count); + +static struct device_attribute ledtrig_blkdev_attr_add = + __ATTR(add_blkdev, 0200, NULL, blkdev_add_or_del); + +static struct device_attribute ledtrig_blkdev_attr_del = + __ATTR(delete_blkdev, 0200, NULL, blkdev_add_or_del); + +static ssize_t blkdev_add_or_del(struct device *const dev, + struct device_attribute *const attr, + const char *const buf, const size_t count) +{ + struct ledtrig_blkdev_led *const led = led_trigger_get_drvdata(dev); + const char *const disk_name = blkdev_skip_space(buf); + const char *const endp = blkdev_find_space(disk_name); + const ptrdiff_t name_len = endp - disk_name; /* always >= 0 */ + int ret; + + if (name_len == 0) { + pr_info("blkdev LED: empty block device name\n"); + return -EINVAL; + } + + if (attr == &ledtrig_blkdev_attr_del) { + blkdev_disk_delete(led, disk_name, name_len); + } else { /* attr == &ledtrig_blkdev_attr_add */ + ret = blkdev_disk_add(led, disk_name, name_len); + if (ret != 0) + return ret; + } + + /* + * Consume everything up to the next non-whitespace token (or the end + * of the input). Avoids "empty block device name" error if there is + * whitespace after the last token (e.g. a newline). + */ + return blkdev_skip_space(endp) - buf; +} -- 2.31.1