thinkpad_acpi: save kbdlight state on suspend and restore it on resume

Override default LED class suspend/resume handles, by keeping track of
the brightness level before suspending so that it can be automatically
restored on resume by calling default resume handler.

Signed-off-by: Marco Trevisan (Treviño) <mail@3v1n0.net>
Acked-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Darren Hart <dvhart@linux.intel.com>

1 files changed, 40 insertions, 3 deletions

diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c
index e305ab541a22..5f09f161765f 100644
--- a/drivers/platform/x86/thinkpad_acpi.c
+++ b/drivers/platform/x86/thinkpad_acpi.c
@@ -5001,6 +5001,8 @@ static int kbdlight_set_level(int level)
         return 0;
 }
 
+static int kbdlight_set_level_and_update(int level);
+
 static int kbdlight_get_level(void)
 {
         int status = 0;
@@ -5068,7 +5070,7 @@ static void kbdlight_set_worker(struct work_struct *work)
                         container_of(work, struct tpacpi_led_classdev, work);
 
         if (likely(tpacpi_lifecycle == TPACPI_LIFE_RUNNING))
-                kbdlight_set_level(data->new_state);
+                kbdlight_set_level_and_update(data->new_state);
 }
 
 static void kbdlight_sysfs_set(struct led_classdev *led_cdev,
@@ -5099,7 +5101,6 @@ static struct tpacpi_led_classdev tpacpi_led_kbdlight = {
                 .max_brightness = 2,
                 .brightness_set = &kbdlight_sysfs_set,
                 .brightness_get = &kbdlight_sysfs_get,
-                .flags          = LED_CORE_SUSPENDRESUME,
         }
 };
 
@@ -5137,6 +5138,20 @@ static void kbdlight_exit(void)
         flush_workqueue(tpacpi_wq);
 }
 
+static int kbdlight_set_level_and_update(int level)
+{
+        int ret;
+        struct led_classdev *led_cdev;
+
+        ret = kbdlight_set_level(level);
+        led_cdev = &tpacpi_led_kbdlight.led_classdev;
+
+        if (ret == 0 && !(led_cdev->flags & LED_SUSPENDED))
+                led_cdev->brightness = level;
+
+        return ret;
+}
+
 static int kbdlight_read(struct seq_file *m)
 {
         int level;
@@ -5177,13 +5192,35 @@ static int kbdlight_write(char *buf)
         if (level == -1)
                 return -EINVAL;
 
-        return kbdlight_set_level(level);
+        return kbdlight_set_level_and_update(level);
+}
+
+static void kbdlight_suspend(void)
+{
+        struct led_classdev *led_cdev;
+
+        if (!tp_features.kbdlight)
+                return;
+
+        led_cdev = &tpacpi_led_kbdlight.led_classdev;
+        led_update_brightness(led_cdev);
+        led_classdev_suspend(led_cdev);
+}
+
+static void kbdlight_resume(void)
+{
+        if (!tp_features.kbdlight)
+                return;
+
+        led_classdev_resume(&tpacpi_led_kbdlight.led_classdev);
 }
 
 static struct ibm_struct kbdlight_driver_data = {
         .name = "kbdlight",
         .read = kbdlight_read,
         .write = kbdlight_write,
+        .suspend = kbdlight_suspend,
+        .resume = kbdlight_resume,
         .exit = kbdlight_exit,
 };