/sys/class/leds/<led>/blink_time controls - per-LED blink duration /sys/class/leds/<led>/interval - global frequency with which devices are checked for activity and LEDs are blinked Enforce 25 millisecond minimum for both attributes Signed-off-by: Ian Pilcher <arequipeno@gmail.com> --- drivers/leds/trigger/ledtrig-blkdev.c | 63 +++++++++++++++++++++++++++ 1 file changed, 63 insertions(+) diff --git a/drivers/leds/trigger/ledtrig-blkdev.c b/drivers/leds/trigger/ledtrig-blkdev.c index 15b15aefdfd8..481b2d142db2 100644 --- a/drivers/leds/trigger/ledtrig-blkdev.c +++ b/drivers/leds/trigger/ledtrig-blkdev.c @@ -528,3 +528,66 @@ static ssize_t blkdev_add_or_del(struct device *const dev, */ return blkdev_skip_space(endp) - buf; } + + +/* + * + * blink_time & interval device attributes + * + */ + +static ssize_t blkdev_time_show(struct device *const dev, + struct device_attribute *const attr, + char *const buf); + +static ssize_t blkdev_time_store(struct device *const dev, + struct device_attribute *const attr, + const char *const buf, const size_t count); + +static struct device_attribute ledtrig_blkdev_attr_blink_time = + __ATTR(blink_time, 0644, blkdev_time_show, blkdev_time_store); + +static struct device_attribute ledtrig_blkdev_attr_interval = + __ATTR(interval, 0644, blkdev_time_show, blkdev_time_store); + +static ssize_t blkdev_time_show(struct device *const dev, + struct device_attribute *const attr, + char *const buf) +{ + const struct ledtrig_blkdev_led *const led = + led_trigger_get_drvdata(dev); + unsigned int value; + + if (attr == &ledtrig_blkdev_attr_blink_time) + value = READ_ONCE(led->blink_msec); + else // attr == &ledtrig_blkdev_attr_interval + value = jiffies_to_msecs(READ_ONCE(ledtrig_blkdev_interval)); + + return sprintf(buf, "%u\n", value); +} + +static ssize_t blkdev_time_store(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); + unsigned int value; + int ret; + + ret = kstrtouint(buf, 0, &value); + if (ret != 0) + return ret; + + if (value < LEDTRIG_BLKDEV_MIN_TIME) { + pr_info("blkdev LED: attempt to set time < %s milliseconds\n", + __stringify(LEDTRIG_BLKDEV_MIN_TIME)); + return -ERANGE; + } + + if (attr == &ledtrig_blkdev_attr_blink_time) + WRITE_ONCE(led->blink_msec, value); + else // attr == &ledtrig_blkdev_attr_interval + WRITE_ONCE(ledtrig_blkdev_interval, msecs_to_jiffies(value)); + + return count; +} -- 2.31.1