leds: hw acceleration for Clevo mail LED driver

Add support for hardware accelerated LED blinking for the mail LED
commonly found on Clevo notebooks.

Signed-off-by: Márton Németh <nm127@freemail.hu>
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>

2 files changed, 42 insertions, 3 deletions

diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index 659448ead685..922c3df548a5 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -122,9 +122,11 @@ config LEDS_CLEVO_MAIL
           programs through the leds subsystem. This LED have three
           known mode: off, blink at 0.5Hz and blink at 1Hz.
 
-          As this LED cannot change it's brightness it blinks instead.
-          The brightness value 0 means off, 1..127 means blink at 0.5Hz
-          and 128..255 means blink at 1Hz.
+          The driver supports two kinds of interface: using ledtrig-timer
+          or through /sys/class/leds/clevo::mail/brightness. As this LED
+          cannot change it's brightness it blinks instead. The brightness
+          value 0 means off, 1..127 means blink at 0.5Hz and 128..255 means
+          blink at 1Hz.
 
           This module can drive the mail LED for the following notebooks:
 
diff --git a/drivers/leds/leds-clevo-mail.c b/drivers/leds/leds-clevo-mail.c
index 49a7972459c9..6c3d33b8e383 100644
--- a/drivers/leds/leds-clevo-mail.c
+++ b/drivers/leds/leds-clevo-mail.c
@@ -92,9 +92,46 @@ static void clevo_mail_led_set(struct led_classdev *led_cdev,
 
 }
 
+static int clevo_mail_led_blink(struct led_classdev *led_cdev,
+                                unsigned long* delay_on,
+                                unsigned long* delay_off)
+{
+        int status = -EINVAL;
+
+        if (*delay_on == 0 /* ms */ && *delay_off == 0 /* ms */) {
+                /* Special case: the leds subsystem requested us to
+                 * chose one user friendly blinking of the LED, and
+                 * start it. Let's blink the led slowly (0.5Hz).
+                 */
+                *delay_on = 1000; /* ms */
+                *delay_off = 1000; /* ms */
+                i8042_command(NULL, CLEVO_MAIL_LED_BLINK_0_5HZ);
+                status = 0;
+
+        } else if (*delay_on == 500 /* ms */ && *delay_off == 500 /* ms */) {
+                /* blink the led with 1Hz */
+                i8042_command(NULL, CLEVO_MAIL_LED_BLINK_1HZ);
+                status = 0;
+
+        } else if (*delay_on == 1000 /* ms */ && *delay_off == 1000 /* ms */) {
+                /* blink the led with 0.5Hz */
+                i8042_command(NULL, CLEVO_MAIL_LED_BLINK_0_5HZ);
+                status = 0;
+
+        } else {
+                printk(KERN_DEBUG KBUILD_MODNAME
+                       ": clevo_mail_led_blink(..., %lu, %lu),"
+                       " returning -EINVAL (unsupported)\n",
+                       *delay_on, *delay_off);
+        }
+
+        return status;
+}
+
 static struct led_classdev clevo_mail_led = {
         .name                   = "clevo::mail",
         .brightness_set         = clevo_mail_led_set,
+        .blink_set              = clevo_mail_led_blink,
 };
 
 static int __init clevo_mail_led_probe(struct platform_device *pdev)