sony-laptop: keyboard backlight fixes

Restore the original state on module removal, set the latest values on
resume.
When setting the keyboard backlight mode try to turn on/off backlight
immediately.

[malattia@linux.it: patch taken from a largely modified sony-laptop.c,
ported and slightly modified to use defines already available.]

Signed-off-by: Mattia Dongili <malattia@linux.it>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

1 files changed, 34 insertions, 1 deletions

diff --git a/drivers/platform/x86/sony-laptop.c b/drivers/platform/x86/sony-laptop.c
index 33d9555470c3..8f709aec4da0 100644
--- a/drivers/platform/x86/sony-laptop.c
+++ b/drivers/platform/x86/sony-laptop.c
@@ -138,6 +138,8 @@ MODULE_PARM_DESC(kbd_backlight_timeout,
                  "1 for 30 seconds, 2 for 60 seconds and 3 to disable timeout "
                  "(default: 0)");
 
+static void sony_nc_kbd_backlight_resume(void);
+
 enum sony_nc_rfkill {
         SONY_WIFI,
         SONY_BLUETOOTH,
@@ -1176,6 +1178,9 @@ static int sony_nc_resume(struct acpi_device *device)
         /* re-read rfkill state */
         sony_nc_rfkill_update();
 
+        /* restore kbd backlight states */
+        sony_nc_kbd_backlight_resume();
+
         return 0;
 }
 
@@ -1363,6 +1368,7 @@ out_no_enum:
 #define KBDBL_HANDLER   0x137
 #define KBDBL_PRESENT   0xB00
 #define SET_MODE        0xC00
+#define SET_STATE       0xD00
 #define SET_TIMEOUT     0xE00
 
 struct kbd_backlight {
@@ -1385,6 +1391,10 @@ static ssize_t __sony_nc_kbd_backlight_mode_set(u8 value)
                                 (value << 0x10) | SET_MODE, &result))
                 return -EIO;
 
+        /* Try to turn the light on/off immediately */
+        sony_call_snc_handle(KBDBL_HANDLER, (value << 0x10) | SET_STATE,
+                        &result);
+
         kbdbl_handle->mode = value;
 
         return 0;
@@ -1466,7 +1476,7 @@ static int sony_nc_kbd_backlight_setup(struct platform_device *pd)
 {
         int result;
 
-        if (sony_call_snc_handle(0x137, KBDBL_PRESENT, &result))
+        if (sony_call_snc_handle(KBDBL_HANDLER, KBDBL_PRESENT, &result))
                 return 0;
         if (!(result & 0x02))
                 return 0;
@@ -1509,13 +1519,36 @@ outkzalloc:
 static int sony_nc_kbd_backlight_cleanup(struct platform_device *pd)
 {
         if (kbdbl_handle) {
+                int result;
+
                 device_remove_file(&pd->dev, &kbdbl_handle->mode_attr);
                 device_remove_file(&pd->dev, &kbdbl_handle->timeout_attr);
+
+                /* restore the default hw behaviour */
+                sony_call_snc_handle(KBDBL_HANDLER, 0x1000 | SET_MODE, &result);
+                sony_call_snc_handle(KBDBL_HANDLER, SET_TIMEOUT, &result);
+
                 kfree(kbdbl_handle);
         }
         return 0;
 }
 
+static void sony_nc_kbd_backlight_resume(void)
+{
+        int ignore = 0;
+
+        if (!kbdbl_handle)
+                return;
+
+        if (kbdbl_handle->mode == 0)
+                sony_call_snc_handle(KBDBL_HANDLER, SET_MODE, &ignore);
+
+        if (kbdbl_handle->timeout != 0)
+                sony_call_snc_handle(KBDBL_HANDLER,
+                                (kbdbl_handle->timeout << 0x10) | SET_TIMEOUT,
+                                &ignore);
+}
+
 static void sony_nc_backlight_setup(void)
 {
         acpi_handle unused;