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asus-laptop: add backlight support
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Adds backlight support using backlight class. We now
change the brightness *and toggle the backlight !* via
/sys/class/backlight/asus-laptop/.

If the user switchs the backlight using the keyboard,
asus_hotk_notify looks for ATKD_LCD_OFF and ATKD_LCD_ON events,
and stores the right state into hotk->status and bd->props->power .

Signed-off-by: Corentin Chary <corentincj@iksaif.net>
Signed-off-by: Len Brown <len.brown@intel.com>
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Corentin Chary authored and Len Brown committed Jan 30, 2007
1 parent 4564de1 commit 6b7091e
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Showing 2 changed files with 183 additions and 1 deletion.
1 change: 1 addition & 0 deletions drivers/misc/Kconfig
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Original file line number Diff line number Diff line change
Expand Up @@ -75,6 +75,7 @@ config ASUS_LAPTOP
depends on ACPI
depends on EXPERIMENTAL && !ACPI_ASUS
depends on LEDS_CLASS
depends on BACKLIGHT_CLASS_DEVICE
---help---
This is the new Linux driver for Asus laptops. It may also support some
MEDION, JVC or VICTOR laptops. It makes all the extra buttons generate
Expand Down
183 changes: 182 additions & 1 deletion drivers/misc/asus-laptop.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -40,6 +40,8 @@
#include <linux/types.h>
#include <linux/err.h>
#include <linux/proc_fs.h>
#include <linux/backlight.h>
#include <linux/fb.h>
#include <linux/leds.h>
#include <linux/platform_device.h>
#include <acpi/acpi_drivers.h>
Expand All @@ -55,6 +57,14 @@
#define ASUS_HOTK_FILE "asus-laptop"
#define ASUS_HOTK_PREFIX "\\_SB.ATKD."

/*
* Some events we use, same for all Asus
*/
#define ATKD_BR_UP 0x10
#define ATKD_BR_DOWN 0x20
#define ATKD_LCD_ON 0x33
#define ATKD_LCD_OFF 0x34

/*
* Known bits returned by \_SB.ATKD.HWRS
*/
Expand All @@ -71,6 +81,7 @@
#define TLED_ON 0x08 //touchpad LED
#define RLED_ON 0x10 //Record LED
#define PLED_ON 0x20 //Phone LED
#define LCD_ON 0x40 //LCD backlight

#define ASUS_LOG ASUS_HOTK_FILE ": "
#define ASUS_ERR KERN_ERR ASUS_LOG
Expand Down Expand Up @@ -101,6 +112,19 @@ ASUS_HANDLE(wl_switch, ASUS_HOTK_PREFIX "WLED");
ASUS_HANDLE(bt_switch, ASUS_HOTK_PREFIX "BLED");
ASUS_HANDLE(wireless_status, ASUS_HOTK_PREFIX "RSTS"); /* All new models */

/* Brightness */
ASUS_HANDLE(brightness_set, ASUS_HOTK_PREFIX "SPLV");
ASUS_HANDLE(brightness_get, ASUS_HOTK_PREFIX "GPLV");

/* Backlight */
ASUS_HANDLE(lcd_switch, "\\_SB.PCI0.SBRG.EC0._Q10", /* All new models */
"\\_SB.PCI0.ISA.EC0._Q10", /* A1x */
"\\_SB.PCI0.PX40.ECD0._Q10", /* L3C */
"\\_SB.PCI0.PX40.EC0.Q10", /* M1A */
"\\_SB.PCI0.LPCB.EC0._Q10", /* P30 */
"\\_SB.PCI0.PX40.Q10", /* S1x */
"\\Q10"); /* A2x, L2D, L3D, M2E */

/*
* This is the main structure, we can use it to store anything interesting
* about the hotk device
Expand Down Expand Up @@ -138,6 +162,21 @@ static struct acpi_driver asus_hotk_driver = {
},
};

/* The backlight device /sys/class/backlight */
static struct backlight_device *asus_backlight_device;

/*
* The backlight class declaration
*/
static int read_brightness(struct backlight_device *bd);
static int update_bl_status(struct backlight_device *bd);
static struct backlight_properties asusbl_data = {
.owner = THIS_MODULE,
.get_brightness = read_brightness,
.update_status = update_bl_status,
.max_brightness = 15,
};

/* These functions actually update the LED's, and are called from a
* workqueue. By doing this as separate work rather than when the LED
* subsystem asks, we avoid messing with the Asus ACPI stuff during a
Expand Down Expand Up @@ -253,6 +292,86 @@ ASUS_LED_HANDLER(pled, PLED_ON, 0);
ASUS_LED_HANDLER(rled, RLED_ON, 0);
ASUS_LED_HANDLER(tled, TLED_ON, 0);

static int get_lcd_state(void)
{
return read_status(LCD_ON);
}

static int set_lcd_state(int value)
{
int lcd = 0;
acpi_status status = 0;

lcd = value ? 1 : 0;

if (lcd == get_lcd_state())
return 0;

if(lcd_switch_handle) {
status = acpi_evaluate_object(lcd_switch_handle,
NULL, NULL, NULL);

if (ACPI_FAILURE(status))
printk(ASUS_WARNING "Error switching LCD\n");
}

write_status(NULL, lcd, LCD_ON, 0);
return 0;
}

static void lcd_blank(int blank)
{
struct backlight_device *bd = asus_backlight_device;

if(bd) {
down(&bd->sem);
if(likely(bd->props)) {
bd->props->power = blank;
if(likely(bd->props->update_status))
bd->props->update_status(bd);
}
up(&bd->sem);
}
}

static int read_brightness(struct backlight_device *bd)
{
int value;

if (!read_acpi_int(brightness_get_handle, NULL, &value, NULL))
printk(ASUS_WARNING "Error reading brightness\n");

return value;
}

static int set_brightness(struct backlight_device *bd, int value)
{
int ret = 0;

value = (0 < value) ? ((15 < value) ? 15 : value) : 0;
/* 0 <= value <= 15 */

if (!write_acpi_int(brightness_set_handle, NULL, value, NULL)) {
printk(ASUS_WARNING "Error changing brightness\n");
ret = -EIO;
}

return ret;
}

static int update_bl_status(struct backlight_device *bd)
{
int rv;
int value = bd->props->brightness;

rv = set_brightness(bd, value);
if(rv)
return rv;

value = (bd->props->power == FB_BLANK_UNBLANK) ? 1 : 0;
return set_lcd_state(value);
}

/*
* Platform device handlers
*/
Expand Down Expand Up @@ -378,6 +497,18 @@ static void asus_hotk_notify(acpi_handle handle, u32 event, void *data)
if (!hotk)
return;

/*
* We need to tell the backlight device when the backlight power is
* switched
*/
if (event == ATKD_LCD_ON) {
write_status(NULL, 1, LCD_ON, 0);
lcd_blank(FB_BLANK_UNBLANK);
} else if(event == ATKD_LCD_OFF) {
write_status(NULL, 0, LCD_ON, 0);
lcd_blank(FB_BLANK_POWERDOWN);
}

acpi_bus_generate_event(hotk->device, event,
hotk->event_count[event % 128]++);

Expand Down Expand Up @@ -547,6 +678,11 @@ static int asus_hotk_get_info(void)

ASUS_HANDLE_INIT(wireless_status);

ASUS_HANDLE_INIT(brightness_set);
ASUS_HANDLE_INIT(brightness_get);

ASUS_HANDLE_INIT(lcd_switch);

kfree(model);

return AE_OK;
Expand Down Expand Up @@ -611,10 +747,13 @@ static int asus_hotk_add(struct acpi_device *device)

asus_hotk_found = 1;

/* WLED and BLED are on by default */
/* WLED and BLED are on by default */
write_status(bt_switch_handle, 1, BT_ON, 0);
write_status(wl_switch_handle, 1, WL_ON, 0);

/* LCD Backlight is on by default */
write_status(NULL, 1, LCD_ON, 0);

end:
if (result) {
kfree(hotk->name);
Expand Down Expand Up @@ -642,6 +781,12 @@ static int asus_hotk_remove(struct acpi_device *device, int type)
return 0;
}

static void asus_backlight_exit(void)
{
if(asus_backlight_device)
backlight_device_unregister(asus_backlight_device);
}

#define ASUS_LED_UNREGISTER(object) \
if(object##_led.class_dev \
&& !IS_ERR(object##_led.class_dev)) \
Expand All @@ -659,6 +804,7 @@ static void asus_led_exit(void)

static void __exit asus_laptop_exit(void)
{
asus_backlight_exit();
asus_led_exit();

acpi_bus_unregister_driver(&asus_hotk_driver);
Expand All @@ -669,6 +815,34 @@ static void __exit asus_laptop_exit(void)
kfree(asus_info);
}

static int asus_backlight_init(struct device * dev)
{
struct backlight_device *bd;

if(brightness_set_handle && lcd_switch_handle) {
bd = backlight_device_register (ASUS_HOTK_FILE, dev,
NULL, &asusbl_data);
if (IS_ERR (bd)) {
printk(ASUS_ERR
"Could not register asus backlight device\n");
asus_backlight_device = NULL;
return PTR_ERR(bd);
}

asus_backlight_device = bd;

down(&bd->sem);
if(likely(bd->props)) {
bd->props->brightness = read_brightness(NULL);
bd->props->power = FB_BLANK_UNBLANK;
if(likely(bd->props->update_status))
bd->props->update_status(bd);
}
up(&bd->sem);
}
return 0;
}

static int asus_led_register(acpi_handle handle,
struct led_classdev * ldev,
struct device * dev)
Expand Down Expand Up @@ -739,6 +913,10 @@ static int __init asus_laptop_init(void)

dev = acpi_get_physical_device(hotk->device->handle);

result = asus_backlight_init(dev);
if(result)
goto fail_backlight;

result = asus_led_init(dev);
if(result)
goto fail_led;
Expand Down Expand Up @@ -778,6 +956,9 @@ static int __init asus_laptop_init(void)
asus_led_exit();

fail_led:
asus_backlight_exit();

fail_backlight:

return result;
}
Expand Down

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