samsung-laptop: add keyboard backlight support

Signed-off-by: Corentin Chary <corentincj@iksaif.net>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index 1906fc4762dee799525516c75186e16d6abbcc4a..912ffef0f148c343d09fcd3ec306db2d20a74045 100644 (file)
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -771,6 +771,8 @@ config SAMSUNG_LAPTOP
        depends on X86
        depends on RFKILL || RFKILL = n
        depends on BACKLIGHT_CLASS_DEVICE
+       select LEDS_CLASS
+       select NEW_LEDS
        ---help---
          This module implements a driver for a wide range of different
          Samsung laptops.  It offers control over the different

diff --git a/drivers/platform/x86/samsung-laptop.c b/drivers/platform/x86/samsung-laptop.c
index b8d2145981e06b43eb24c2ebde264046ed139a19..fd0ebedc86e217f6416171c61b1c4542fc3b63e7 100644 (file)
--- a/drivers/platform/x86/samsung-laptop.c
+++ b/drivers/platform/x86/samsung-laptop.c
@@ -17,6 +17,7 @@
 #include <linux/delay.h>
 #include <linux/pci.h>
 #include <linux/backlight.h>
+#include <linux/leds.h>
 #include <linux/fb.h>
 #include <linux/dmi.h>
 #include <linux/platform_device.h>
@@ -112,6 +113,9 @@ struct sabi_commands {
        u16 get_usb_charge;
        u16 set_usb_charge;
 
+       /* 0x81 to read, (0x82 | level << 8) to set, 0xaabb to enable */
+       u16 kbd_backlight;
+
        /*
         * Tell the BIOS that Linux is running on this machine.
         * 81 is on, 80 is off
@@ -171,6 +175,8 @@ static const struct sabi_config sabi_configs[] = {
                        .get_usb_charge = 0xFFFF,
                        .set_usb_charge = 0xFFFF,
 
+                       .kbd_backlight = 0xFFFF,
+
                        .set_linux = 0x0a,
                },
 
@@ -224,6 +230,8 @@ static const struct sabi_config sabi_configs[] = {
                        .get_usb_charge = 0x67,
                        .set_usb_charge = 0x68,
 
+                       .kbd_backlight = 0x78,
+
                        .set_linux = 0xff,
                },
 
@@ -290,6 +298,11 @@ struct samsung_laptop {
        struct backlight_device *backlight_device;
        struct rfkill *rfk;
 
+       struct led_classdev kbd_led;
+       int kbd_led_wk;
+       struct workqueue_struct *led_workqueue;
+       struct work_struct kbd_led_work;
+
        struct samsung_laptop_debug debug;
 
        bool handle_backlight;
@@ -757,6 +770,122 @@ static int __init samsung_rfkill_init(struct samsung_laptop *samsung)
        return 0;
 }
 
+static int kbd_backlight_enable(struct samsung_laptop *samsung)
+{
+       const struct sabi_commands *commands = &samsung->config->commands;
+       struct sabi_data data;
+       int retval;
+
+       if (commands->kbd_backlight == 0xFFFF)
+               return -ENODEV;
+
+       memset(&data, 0, sizeof(data));
+       data.d0 = 0xaabb;
+       retval = sabi_command(samsung, commands->kbd_backlight,
+                             &data, &data);
+
+       if (retval)
+               return retval;
+
+       if (data.d0 != 0xccdd)
+               return -ENODEV;
+       return 0;
+}
+
+static int kbd_backlight_read(struct samsung_laptop *samsung)
+{
+       const struct sabi_commands *commands = &samsung->config->commands;
+       struct sabi_data data;
+       int retval;
+
+       memset(&data, 0, sizeof(data));
+       data.data[0] = 0x81;
+       retval = sabi_command(samsung, commands->kbd_backlight,
+                             &data, &data);
+
+       if (retval)
+               return retval;
+
+       return data.data[0];
+}
+
+static int kbd_backlight_write(struct samsung_laptop *samsung, int brightness)
+{
+       const struct sabi_commands *commands = &samsung->config->commands;
+       struct sabi_data data;
+
+       memset(&data, 0, sizeof(data));
+       data.d0 = 0x82 | ((brightness & 0xFF) << 8);
+       return sabi_command(samsung, commands->kbd_backlight,
+                           &data, NULL);
+}
+
+static void kbd_led_update(struct work_struct *work)
+{
+       struct samsung_laptop *samsung;
+
+       samsung = container_of(work, struct samsung_laptop, kbd_led_work);
+       kbd_backlight_write(samsung, samsung->kbd_led_wk);
+}
+
+static void kbd_led_set(struct led_classdev *led_cdev,
+                       enum led_brightness value)
+{
+       struct samsung_laptop *samsung;
+
+       samsung = container_of(led_cdev, struct samsung_laptop, kbd_led);
+
+       if (value > samsung->kbd_led.max_brightness)
+               value = samsung->kbd_led.max_brightness;
+       else if (value < 0)
+               value = 0;
+
+       samsung->kbd_led_wk = value;
+       queue_work(samsung->led_workqueue, &samsung->kbd_led_work);
+}
+
+static enum led_brightness kbd_led_get(struct led_classdev *led_cdev)
+{
+       struct samsung_laptop *samsung;
+
+       samsung = container_of(led_cdev, struct samsung_laptop, kbd_led);
+       return kbd_backlight_read(samsung);
+}
+
+static void samsung_leds_exit(struct samsung_laptop *samsung)
+{
+       if (!IS_ERR_OR_NULL(samsung->kbd_led.dev))
+               led_classdev_unregister(&samsung->kbd_led);
+       if (samsung->led_workqueue)
+               destroy_workqueue(samsung->led_workqueue);
+}
+
+static int __init samsung_leds_init(struct samsung_laptop *samsung)
+{
+       int ret = 0;
+
+       samsung->led_workqueue = create_singlethread_workqueue("led_workqueue");
+       if (!samsung->led_workqueue)
+               return -ENOMEM;
+
+       if (kbd_backlight_enable(samsung) >= 0) {
+               INIT_WORK(&samsung->kbd_led_work, kbd_led_update);
+
+               samsung->kbd_led.name = "samsung::kbd_backlight";
+               samsung->kbd_led.brightness_set = kbd_led_set;
+               samsung->kbd_led.brightness_get = kbd_led_get;
+               samsung->kbd_led.max_brightness = 8;
+
+               ret = led_classdev_register(&samsung->platform_device->dev,
+                                          &samsung->kbd_led);
+       }
+
+       if (ret)
+               samsung_leds_exit(samsung);
+
+       return ret;
+}
+
 static void samsung_backlight_exit(struct samsung_laptop *samsung)
 {
        if (samsung->backlight_device) {
@@ -1366,6 +1495,10 @@ static int __init samsung_init(void)
        if (ret)
                goto error_rfkill;
 
+       ret = samsung_leds_init(samsung);
+       if (ret)
+               goto error_leds;
+
        ret = samsung_debugfs_init(samsung);
        if (ret)
                goto error_debugfs;
@@ -1374,6 +1507,8 @@ static int __init samsung_init(void)
        return ret;
 
 error_debugfs:
+       samsung_leds_exit(samsung);
+error_leds:
        samsung_rfkill_exit(samsung);
 error_rfkill:
        samsung_backlight_exit(samsung);
@@ -1395,6 +1530,7 @@ static void __exit samsung_exit(void)
        samsung = platform_get_drvdata(samsung_platform_device);
 
        samsung_debugfs_exit(samsung);
+       samsung_leds_exit(samsung);
        samsung_rfkill_exit(samsung);
        samsung_backlight_exit(samsung);
        samsung_sysfs_exit(samsung);