thinkpad-acpi: issue backlight class events

Take advantage of the new events capabilities of the backlight class to
notify userspace of backlight changes.

This depends on "backlight: Allow drivers to update the core, and
generate events on changes", by Matthew Garrett.

Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: Matthew Garrett <mjg@redhat.com>
Cc: Richard Purdie <rpurdie@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 23 insertions, 1 deletions

diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c
index 6160813d906a..44061367a10d 100644
--- a/drivers/platform/x86/thinkpad_acpi.c
+++ b/drivers/platform/x86/thinkpad_acpi.c
@@ -22,7 +22,7 @@
  */
 
 #define TPACPI_VERSION "0.23"
-#define TPACPI_SYSFS_VERSION 0x020500
+#define TPACPI_SYSFS_VERSION 0x020600
 
 /*
  *  Changelog:
@@ -6073,6 +6073,12 @@ static int brightness_get(struct backlight_device *bd)
         return status & TP_EC_BACKLIGHT_LVLMSK;
 }
 
+static void tpacpi_brightness_notify_change(void)
+{
+        backlight_force_update(ibm_backlight_device,
+                               BACKLIGHT_UPDATE_HOTKEY);
+}
+
 static struct backlight_ops ibm_backlight_data = {
         .get_brightness = brightness_get,
         .update_status  = brightness_update_status,
@@ -6227,6 +6233,12 @@ static int __init brightness_init(struct ibm_init_struct *iibm)
         ibm_backlight_device->props.brightness = b & TP_EC_BACKLIGHT_LVLMSK;
         backlight_update_status(ibm_backlight_device);
 
+        vdbg_printk(TPACPI_DBG_INIT | TPACPI_DBG_BRGHT,
+                        "brightness: registering brightness hotkeys "
+                        "as change notification\n");
+        tpacpi_hotkey_driver_mask_set(hotkey_driver_mask
+                                | TP_ACPI_HKEY_BRGHTUP_MASK
+                                | TP_ACPI_HKEY_BRGHTDWN_MASK);;
         return 0;
 }
 
@@ -6303,6 +6315,9 @@ static int brightness_write(char *buf)
          * Doing it this way makes the syscall restartable in case of EINTR
          */
         rc = brightness_set(level);
+        if (!rc && ibm_backlight_device)
+                backlight_force_update(ibm_backlight_device,
+                                        BACKLIGHT_UPDATE_SYSFS);
         return (rc == -EINTR)? -ERESTARTSYS : rc;
 }
 
@@ -7702,6 +7717,13 @@ static struct ibm_struct fan_driver_data = {
  */
 static void tpacpi_driver_event(const unsigned int hkey_event)
 {
+        if (ibm_backlight_device) {
+                switch (hkey_event) {
+                case TP_HKEY_EV_BRGHT_UP:
+                case TP_HKEY_EV_BRGHT_DOWN:
+                        tpacpi_brightness_notify_change();
+                }
+        }
 }