Re: PATCH [3/3]: Provide generic backlight support in Toshiba ACPI driver

Re: PATCH [3/3]: Provide generic backlight support in Toshiba ACPI driver

[Andrey Borzenkov]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

> @@ -546,6 +591,12 @@ static int __init toshiba_acpi_init(void
>                         remove_proc_entry(PROC_TOSHIBA, acpi_root_dir);
>         }
>
> +       tosh_backlight_device = backlight_device_register ("tosh-bl", NULL,
> +                                                          &toshbl_data);
> +
> +       if (IS_ERR (tosh_backlight_device))
> +               printk("Failed to register Toshiba backlight device\n");
> +
>         return (ACPI_SUCCESS(status)) ? 0 : -ENODEV;
>  }
>

Should not this be

       if (IS_ERR (tosh_backlight_device)) {
               printk("Failed to register Toshiba backlight device\n");
               tosh_backlight_device = NULL;
       }

> @@ -556,6 +607,8 @@ static void __exit toshiba_acpi_exit(voi
>         if (toshiba_proc_dir)
>                 remove_proc_entry(PROC_TOSHIBA, acpi_root_dir);
>
> +       backlight_device_unregister(tosh_backlight_device);
> +
>         return;
>  }

What if it failed register before?

- -andrey
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PATCH [1/3]: Provide generic backlight support in Asus ACPI driver

[Matthew Garrett]

This allows Asus backlight control to be performed via 
/sys/class/backlight. It does not currently remove the legacy /proc 
interface.

Signed-off-by: Matthew Garrett <mjg59@srcf.ucam.org>

diff -urp drivers/acpi.bak/asus_acpi.c drivers/acpi/asus_acpi.c
--- drivers/acpi.bak/asus_acpi.c	2006-04-03 04:22:10 +0100
+++ a/drivers/acpi/asus_acpi.c	2006-04-18 09:23:58 +0100
@@ -38,6 +38,8 @@
 #include <linux/init.h>
 #include <linux/types.h>
 #include <linux/proc_fs.h>
+#include <linux/backlight.h>
+#include <linux/err.h>
 #include <acpi/acpi_drivers.h>
 #include <acpi/acpi_bus.h>
 #include <asm/uaccess.h>
@@ -82,6 +84,8 @@ MODULE_PARM_DESC(asus_uid, "UID for entr
 module_param(asus_gid, uint, 0);
 MODULE_PARM_DESC(asus_gid, "GID for entries in /proc/acpi/asus.\n");
 
+static struct backlight_device *asus_backlight_device;
+
 /* For each model, all features implemented, 
  * those marked with R are relative to HOTK, A for absolute */
 struct model_data {
@@ -689,7 +693,7 @@ proc_write_lcd(struct file *file, const 
 	return count;
 }
 
-static int read_brightness(void)
+static int read_brightness(struct backlight_device *bd)
 {
 	int value;
 
@@ -711,39 +715,50 @@ static int read_brightness(void)
 /*
  * Change the brightness level
  */
-static void set_brightness(int value)
+static int set_brightness(struct backlight_device *bd, int value)
 {
 	acpi_status status = 0;
 
+	value = (0 < value) ? ((15 < value) ? 15 : value) : 0;
+	/* 0 <= value <= 15 */
+
 	/* SPLV laptop */
 	if (hotk->methods->brightness_set) {
 		if (!write_acpi_int(hotk->handle, hotk->methods->brightness_set,
 				    value, NULL))
 			printk(KERN_WARNING
 			       "Asus ACPI: Error changing brightness\n");
-		return;
+		return -EINVAL;
 	}
 
 	/* No SPLV method if we are here, act as appropriate */
-	value -= read_brightness();
+	value -= read_brightness(NULL);
 	while (value != 0) {
 		status = acpi_evaluate_object(NULL, (value > 0) ?
 					      hotk->methods->brightness_up :
 					      hotk->methods->brightness_down,
 					      NULL, NULL);
 		(value > 0) ? value-- : value++;
-		if (ACPI_FAILURE(status))
+		if (ACPI_FAILURE(status)) {
 			printk(KERN_WARNING
 			       "Asus ACPI: Error changing brightness\n");
+			return -EINVAL;
+		}		
 	}
-	return;
+	return 0;
+}
+
+static int update_brightness(struct backlight_device *bd)
+{
+	int value = bd->props->brightness;
+	return set_brightness(bd, value);
 }
 
 static int
 proc_read_brn(char *page, char **start, off_t off, int count, int *eof,
 	      void *data)
 {
-	return sprintf(page, "%d\n", read_brightness());
+	return sprintf(page, "%d\n", read_brightness(NULL));
 }
 
 static int
@@ -754,9 +769,7 @@ proc_write_brn(struct file *file, const 
 
 	count = parse_arg(buffer, count, &value);
 	if (count > 0) {
-		value = (0 < value) ? ((15 < value) ? 15 : value) : 0;
-		/* 0 <= value <= 15 */
-		set_brightness(value);
+		set_brightness(NULL,value);
 	} else if (count < 0) {
 		printk(KERN_WARNING "Asus ACPI: Error reading user input\n");
 	}
@@ -1207,6 +1220,13 @@ static int asus_hotk_remove(struct acpi_
 	return 0;
 }
 
+static struct backlight_properties asusbl_data = {
+	.owner          = THIS_MODULE,
+	.get_brightness = read_brightness,
+	.update_status  = update_brightness,
+	.max_brightness = 15,
+};
+
 static int __init asus_acpi_init(void)
 {
 	int result;
@@ -1232,11 +1252,24 @@ static int __init asus_acpi_init(void)
 		return -ENODEV;
 	}
 
+	asus_backlight_device = backlight_device_register ("asus_bl", NULL,
+							   &asusbl_data);
+
+	if (IS_ERR (asus_backlight_device)) {
+		printk("Unable to register backlight\n");
+		acpi_bus_unregister_driver(&asus_hotk_driver);
+		remove_proc_entry(PROC_ASUS, acpi_root_dir);
+		
+		acpi_os_free(asus_info);
+		return -ENODEV;
+	}
+
 	return 0;
 }
 
 static void __exit asus_acpi_exit(void)
 {
+	backlight_device_unregister(asus_backlight_device);
 	acpi_bus_unregister_driver(&asus_hotk_driver);
 	remove_proc_entry(PROC_ASUS, acpi_root_dir);
 
diff -urp drivers/acpi.bak/Kconfig drivers/acpi/Kconfig
--- drivers/acpi.bak/Kconfig	2006-04-18 08:51:49 +0100
+++ a/drivers/acpi/Kconfig	2006-04-18 09:20:42 +0100
@@ -167,7 +167,7 @@ config ACPI_NUMA
 
 config ACPI_ASUS
         tristate "ASUS/Medion Laptop Extras"
-	depends on X86
+	depends on X86 && BACKLIGHT_DEVICE
         ---help---
           This driver provides support for extra features of ACPI-compatible
           ASUS laptops. As some of Medion laptops are made by ASUS, it may also

-- 
Matthew Garrett | mjg59@srcf.ucam.org

PATCH [2/3]: Provide generic backlight support in IBM ACPI driver

[Matthew Garrett]

This provides support for altering IBM backlight brightness via 
/sys/class/backlight. It does not remove the legacy /proc interface.

Signed-off-by: Matthew Garrett <mjg59@srcf.ucam.org>

diff -urp drivers/acpi.bak/ibm_acpi.c drivers/acpi/ibm_acpi.c
--- drivers/acpi.bak/ibm_acpi.c	2006-04-03 04:22:10 +0100
+++ a/drivers/acpi/ibm_acpi.c	2006-04-18 09:19:21 +0100
@@ -78,6 +78,8 @@
 #include <linux/init.h>
 #include <linux/types.h>
 #include <linux/proc_fs.h>
+#include <linux/backlight.h>
+#include <linux/err.h>
 #include <asm/uaccess.h>
 
 #include <acpi/acpi_drivers.h>
@@ -243,6 +245,8 @@ struct ibm_struct {
 
 static struct proc_dir_entry *proc_dir = NULL;
 
+static struct backlight_device *ibm_backlight_device;
+
 #define onoff(status,bit) ((status) & (1 << (bit)) ? "on" : "off")
 #define enabled(status,bit) ((status) & (1 << (bit)) ? "enabled" : "disabled")
 #define strlencmp(a,b) (strncmp((a), (b), strlen(b)))
@@ -1318,15 +1322,25 @@ static int ecdump_write(char *buf)
 
 static int brightness_offset = 0x31;
 
+static int brightness_read_value(struct backlight_device *bd)
+{
+	u8 level;
+	if (!acpi_ec_read(brightness_offset, &level))
+		return -EIO;
+
+	level &= 0x7;
+	return level;
+}
+
 static int brightness_read(char *p)
 {
 	int len = 0;
-	u8 level;
+	int level = brightness_read_value(NULL);
 
-	if (!acpi_ec_read(brightness_offset, &level)) {
+	if (level < 0) {
 		len += sprintf(p + len, "level:\t\tunreadable\n");
 	} else {
-		len += sprintf(p + len, "level:\t\t%d\n", level & 0x7);
+		len += sprintf(p + len, "level:\t\t%d\n", level);
 		len += sprintf(p + len, "commands:\tup, down\n");
 		len += sprintf(p + len, "commands:\tlevel <level>"
 			       " (<level> is 0-7)\n");
@@ -1338,9 +1352,38 @@ static int brightness_read(char *p)
 #define BRIGHTNESS_UP	4
 #define BRIGHTNESS_DOWN	5
 
+static int brightness_write_value(struct backlight_device *bd, int value)
+{
+	int current_value = brightness_read_value(bd);
+	int inc;
+	int cmos_cmd; 
+
+	value &= 7;
+
+	cmos_cmd = value > current_value ? BRIGHTNESS_UP : BRIGHTNESS_DOWN;
+
+	inc = value > current_value ? 1 : -1;
+
+	while (value != current_value) {
+		current_value += inc;
+
+		if (!cmos_eval(cmos_cmd))
+			return -EIO;
+		if (!acpi_ec_write(brightness_offset, current_value))
+			return -EIO;
+	}
+
+	return 0;
+}
+
+static int brightness_update_value(struct backlight_device *bd)
+{
+	int value = bd->props->brightness;
+	return brightness_write_value(bd, value);
+}
+
 static int brightness_write(char *buf)
 {
-	int cmos_cmd, inc, i;
 	u8 level;
 	int new_level;
 	char *cmd;
@@ -1360,14 +1403,8 @@ static int brightness_write(char *buf)
 		} else
 			return -EINVAL;
 
-		cmos_cmd = new_level > level ? BRIGHTNESS_UP : BRIGHTNESS_DOWN;
-		inc = new_level > level ? 1 : -1;
-		for (i = level; i != new_level; i += inc) {
-			if (!cmos_eval(cmos_cmd))
-				return -EIO;
-			if (!acpi_ec_write(brightness_offset, i + inc))
-				return -EIO;
-		}
+		brightness_write_value(NULL, new_level);
+		
 	}
 
 	return 0;
@@ -1895,10 +1932,20 @@ IBM_PARAM(brightness);
 IBM_PARAM(volume);
 IBM_PARAM(fan);
 
+
+static struct backlight_properties ibmbl_data = {
+        .owner          = THIS_MODULE,
+        .get_brightness = brightness_read_value,
+        .update_status  = brightness_update_value,
+        .max_brightness = 7,
+};
+
 static void acpi_ibm_exit(void)
 {
 	int i;
 
+	backlight_device_unregister(ibm_backlight_device);
+
 	for (i = ARRAY_SIZE(ibms) - 1; i >= 0; i--)
 		ibm_exit(&ibms[i]);
 
@@ -1966,6 +2013,11 @@ static int __init acpi_ibm_init(void)
 		}
 	}
 
+	ibm_backlight_device = backlight_device_register ("ibm_bl", NULL,
+							  &ibmbl_data);
+        if (IS_ERR (ibm_backlight_device))
+		acpi_ibm_exit();
+
 	return 0;
 }
 
diff -urp drivers/acpi.bak/Kconfig drivers/acpi/Kconfig
--- drivers/acpi.bak/Kconfig	2006-04-18 08:51:49 +0100
+++ a/drivers/acpi/Kconfig	2006-04-18 09:13:09 +0100
@@ -195,7 +195,7 @@ config ACPI_ASUS
           
 config ACPI_IBM
 	tristate "IBM ThinkPad Laptop Extras"
-	depends on X86
+	depends on X86 && BACKLIGHT_DEVICE
 	---help---
 	  This is a Linux ACPI driver for the IBM ThinkPad laptops. It adds
 	  support for Fn-Fx key combinations, Bluetooth control, video

-- 
Matthew Garrett | mjg59@srcf.ucam.org

PATCH [3/3]: Provide generic backlight support in Toshiba ACPI driver

[Matthew Garrett]

This patch provides support for altering Toshiba backlight brightness 
via /sys/class/backlight. It does not remove the legacy /proc interface.

Signed-off-by: Matthew Garrett <mjg59@srcf.ucam.org>

diff -urp drivers/acpi.bak/Kconfig drivers/acpi/Kconfig
--- drivers/acpi.bak/Kconfig	2006-04-18 08:51:49 +0100
+++ a/drivers/acpi/Kconfig	2006-04-18 09:24:45 +0100
@@ -219,7 +219,7 @@ config ACPI_IBM_DOCK
 
 config ACPI_TOSHIBA
 	tristate "Toshiba Laptop Extras"
-	depends on X86
+	depends on X86 && BACKLIGHT_DEVICE
 	---help---
 	  This driver adds support for access to certain system settings
 	  on "legacy free" Toshiba laptops.  These laptops can be recognized by
diff -urp drivers/acpi.bak/toshiba_acpi.c drivers/acpi/toshiba_acpi.c
--- drivers/acpi.bak/toshiba_acpi.c	2006-04-03 04:22:10 +0100
+++ a/drivers/acpi/toshiba_acpi.c	2006-04-18 09:26:41 +0100
@@ -41,6 +41,7 @@
 #include <linux/init.h>
 #include <linux/types.h>
 #include <linux/proc_fs.h>
+#include <linux/backlight.h>
 #include <asm/uaccess.h>
 
 #include <acpi/acpi_drivers.h>
@@ -97,6 +98,8 @@ MODULE_LICENSE("GPL");
 #define HCI_VIDEO_OUT_CRT		0x2
 #define HCI_VIDEO_OUT_TV		0x4
 
+static struct backlight_device *tosh_backlight_device;
+
 /* utility
  */
 
@@ -289,6 +292,19 @@ static char *read_lcd(char *p)
 	return p;
 }
 
+static int tosh_get_brightness(struct backlight_device *bd)
+{
+	int brightness;
+	u32 hci_result;
+
+	hci_read1(HCI_LCD_BRIGHTNESS, &brightness, &hci_result);
+	if (hci_result == HCI_SUCCESS) {
+		brightness = brightness >> HCI_LCD_BRIGHTNESS_SHIFT;
+		return brightness;
+	} else
+		return 0;
+}
+
 static unsigned long write_lcd(const char *buffer, unsigned long count)
 {
 	int value;
@@ -307,6 +323,28 @@ static unsigned long write_lcd(const cha
 	return count;
 }
 
+static int tosh_set_brightness(struct backlight_device *bd, int brightness)
+{
+	u32 hci_result;
+
+	if (brightness >= 0 && brightness < HCI_LCD_BRIGHTNESS_LEVELS) {
+		brightness= brightness << HCI_LCD_BRIGHTNESS_SHIFT;
+		hci_write1(HCI_LCD_BRIGHTNESS, brightness, &hci_result);
+		if (hci_result != HCI_SUCCESS)
+			return -EFAULT;
+	} else {
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int tosh_update_brightness(struct backlight_device *bd)
+{
+	int value = bd->props->brightness;
+	return tosh_set_brightness(bd, value);
+}
+
 static char *read_video(char *p)
 {
 	u32 hci_result;
@@ -477,6 +515,13 @@ static ProcItem proc_items[] = {
 	{NULL}
 };
 
+static struct backlight_properties toshbl_data = {
+	.owner          = THIS_MODULE,
+	.get_brightness = tosh_get_brightness,
+	.update_status  = tosh_update_brightness,
+	.max_brightness = HCI_LCD_BRIGHTNESS_LEVELS,
+};
+
 static acpi_status __init add_device(void)
 {
 	struct proc_dir_entry *proc;
@@ -546,6 +591,12 @@ static int __init toshiba_acpi_init(void
 			remove_proc_entry(PROC_TOSHIBA, acpi_root_dir);
 	}
 
+	tosh_backlight_device = backlight_device_register ("tosh-bl", NULL,
+							   &toshbl_data);
+
+	if (IS_ERR (tosh_backlight_device))
+		printk("Failed to register Toshiba backlight device\n");
+
 	return (ACPI_SUCCESS(status)) ? 0 : -ENODEV;
 }
 
@@ -556,6 +607,8 @@ static void __exit toshiba_acpi_exit(voi
 	if (toshiba_proc_dir)
 		remove_proc_entry(PROC_TOSHIBA, acpi_root_dir);
 
+	backlight_device_unregister(tosh_backlight_device);
+
 	return;
 }

-- 
Matthew Garrett | mjg59@srcf.ucam.org

Re: PATCH [1/3]: Provide generic backlight support in Asus ACPI driver

[Patrick Mochel]

On Tue, Apr 18, 2006 at 09:29:52AM +0100, Matthew Garrett wrote:
> This allows Asus backlight control to be performed via 
> /sys/class/backlight. It does not currently remove the legacy /proc 
> interface.

Neat, though a few questions that apply to each of the three ACPI platform drivers..


> diff -urp drivers/acpi.bak/asus_acpi.c drivers/acpi/asus_acpi.c

> +static struct backlight_device *asus_backlight_device;
> +

Why is this dynamically allocated? If there is only one per driver, then the
register() function could take that as a parameter -- instead of passing various
variable to initialize it with -- and return an error. 

> -static int read_brightness(void)
> +static int read_brightness(struct backlight_device *bd)

It seems that you're always passing NULL to this. And, if you're not passing NULL,
aren't you always referencing the single global instance above? 

> -static void set_brightness(int value)
> +static int set_brightness(struct backlight_device *bd, int value)
>  {
>  	acpi_status status = 0;
>  
> +	value = (0 < value) ? ((15 < value) ? 15 : value) : 0;
> +	/* 0 <= value <= 15 */

Is there something wrong with:

	if (value < 0)
		value = 0;
	else if (value > 15)
		value = 15;

? Or, could you just make the parameter an unsigned int and just keep the 2nd check? 

> -		value = (0 < value) ? ((15 < value) ? 15 : value) : 0;
> -		/* 0 <= value <= 15 */
> -		set_brightness(value);
> +		set_brightness(NULL,value);

There should be a space between parameters. 

> +	asus_backlight_device = backlight_device_register ("asus_bl", NULL,
> +							   &asusbl_data);
> +
> +	if (IS_ERR (asus_backlight_device)) {
> +		printk("Unable to register backlight\n");

Could you print the name of the driver? 

> +		acpi_bus_unregister_driver(&asus_hotk_driver);
> +		remove_proc_entry(PROC_ASUS, acpi_root_dir);

If the backlight fails to register, does it mean that these must also fail? 


Thanks,


	Patrick

PATCH [1/3]: Provide generic backlight support in Asus ACPI driver

[Matthew Garrett]

Here are some fixed-up versions of my patches to move acpi drivers 
towards using the standard backlight interface. I've kept the dynamic 
allocation of backlight_device for now, since changing that would also 
mean changing the backlight core code and updating other drivers.

Signed-off-by: Matthew Garrett <mjg59@srcf.ucam.org>

diff -ur drivers/acpi.bak/asus_acpi.c drivers/acpi/asus_acpi.c
--- drivers/acpi.bak/asus_acpi.c	2006-04-03 04:22:10 +0100
+++ a/drivers/acpi/asus_acpi.c	2006-04-19 19:29:50 +0100
@@ -38,6 +38,8 @@
 #include <linux/init.h>
 #include <linux/types.h>
 #include <linux/proc_fs.h>
+#include <linux/backlight.h>
+#include <linux/err.h>
 #include <acpi/acpi_drivers.h>
 #include <acpi/acpi_bus.h>
 #include <asm/uaccess.h>
@@ -82,6 +84,8 @@
 module_param(asus_gid, uint, 0);
 MODULE_PARM_DESC(asus_gid, "GID for entries in /proc/acpi/asus.\n");
 
+static struct backlight_device *asus_backlight_device;
+
 /* For each model, all features implemented, 
  * those marked with R are relative to HOTK, A for absolute */
 struct model_data {
@@ -689,7 +693,7 @@
 	return count;
 }
 
-static int read_brightness(void)
+static int read_brightness(struct backlight_device *bd)
 {
 	int value;
 
@@ -711,39 +715,50 @@
 /*
  * Change the brightness level
  */
-static void set_brightness(int value)
+static int set_brightness(unsigned int value)
 {
 	acpi_status status = 0;
 
+	if (value > 15)
+		value = 15;
+
 	/* SPLV laptop */
 	if (hotk->methods->brightness_set) {
 		if (!write_acpi_int(hotk->handle, hotk->methods->brightness_set,
 				    value, NULL))
 			printk(KERN_WARNING
 			       "Asus ACPI: Error changing brightness\n");
-		return;
+		return -EINVAL;
 	}
 
 	/* No SPLV method if we are here, act as appropriate */
-	value -= read_brightness();
+	value -= read_brightness(NULL);
 	while (value != 0) {
 		status = acpi_evaluate_object(NULL, (value > 0) ?
 					      hotk->methods->brightness_up :
 					      hotk->methods->brightness_down,
 					      NULL, NULL);
 		(value > 0) ? value-- : value++;
-		if (ACPI_FAILURE(status))
+		if (ACPI_FAILURE(status)) {
 			printk(KERN_WARNING
 			       "Asus ACPI: Error changing brightness\n");
+			return -EINVAL;
+		}		
 	}
-	return;
+	return 0;
+}
+
+static int update_brightness(struct backlight_device *bd)
+{
+	int value = bd->props->brightness;
+	return set_brightness (value);
 }
 
 static int
 proc_read_brn(char *page, char **start, off_t off, int count, int *eof,
 	      void *data)
 {
-	return sprintf(page, "%d\n", read_brightness());
+	return sprintf(page, "%d\n", read_brightness(NULL));
 }
 
 static int
@@ -754,9 +769,7 @@
 
 	count = parse_arg(buffer, count, &value);
 	if (count > 0) {
-		value = (0 < value) ? ((15 < value) ? 15 : value) : 0;
-		/* 0 <= value <= 15 */
-		set_brightness(value);
+		set_brightness(value);
 	} else if (count < 0) {
 		printk(KERN_WARNING "Asus ACPI: Error reading user input\n");
 	}
@@ -1207,6 +1220,13 @@
 	return 0;
 }
 
+static struct backlight_properties asusbl_data = {
+	.owner          = THIS_MODULE,
+	.get_brightness = read_brightness,
+	.update_status  = update_brightness,
+	.max_brightness = 15,
+};
+
 static int __init asus_acpi_init(void)
 {
 	int result;
@@ -1232,15 +1252,26 @@
 		return -ENODEV;
 	}
 
+	asus_backlight_device = backlight_device_register("asus_bl", NULL,
+							   &asusbl_data);
+
+	if (IS_ERR (asus_backlight_device)) {
+		printk("Unable to register ASUS backlight\n");
+		asus_backlight_device = NULL;
+	}
+
 	return 0;
 }
 
 static void __exit asus_acpi_exit(void)
 {
-	acpi_bus_unregister_driver(&asus_hotk_driver);
-	remove_proc_entry(PROC_ASUS, acpi_root_dir);
+	if (asus_backlight_device)
+		backlight_device_unregister(asus_backlight_device);
+
+	acpi_bus_unregister_driver (&asus_hotk_driver);
+	remove_proc_entry (PROC_ASUS, acpi_root_dir);
 
-	acpi_os_free(asus_info);
+	acpi_os_free (asus_info);
 
 	return;
 }
diff -ur drivers/acpi.bak/Kconfig drivers/acpi/Kconfig
--- drivers/acpi.bak/Kconfig	2006-04-18 08:51:49 +0100
+++ a/drivers/acpi/Kconfig	2006-04-19 19:27:08 +0100
@@ -168,6 +168,7 @@
 config ACPI_ASUS
         tristate "ASUS/Medion Laptop Extras"
 	depends on X86
+	select BACKLIGHT_DEVICE
         ---help---
           This driver provides support for extra features of ACPI-compatible
           ASUS laptops. As some of Medion laptops are made by ASUS, it may also


-- 
Matthew Garrett | mjg59@srcf.ucam.org

PATCH [2/3]: Provide generic backlight support in IBM ACPI driver

[Matthew Garrett]

Signed-off-by: Matthew Garrett <mjg59@srcf.ucam.org>

diff -ur drivers/acpi.bak/ibm_acpi.c drivers/acpi/ibm_acpi.c
--- drivers/acpi.bak/ibm_acpi.c	2006-04-03 04:22:10 +0100
+++ a/drivers/acpi/ibm_acpi.c	2006-04-19 19:40:48 +0100
@@ -78,6 +78,8 @@
 #include <linux/init.h>
 #include <linux/types.h>
 #include <linux/proc_fs.h>
+#include <linux/backlight.h>
+#include <linux/err.h>
 #include <asm/uaccess.h>
 
 #include <acpi/acpi_drivers.h>
@@ -243,6 +245,8 @@
 
 static struct proc_dir_entry *proc_dir = NULL;
 
+static struct backlight_device *ibm_backlight_device;
+
 #define onoff(status,bit) ((status) & (1 << (bit)) ? "on" : "off")
 #define enabled(status,bit) ((status) & (1 << (bit)) ? "enabled" : "disabled")
 #define strlencmp(a,b) (strncmp((a), (b), strlen(b)))
@@ -1318,15 +1322,25 @@
 
 static int brightness_offset = 0x31;
 
+static int brightness_read_value(struct backlight_device *bd)
+{
+	u8 level;
+	if (!acpi_ec_read(brightness_offset, &level))
+		return -EIO;
+
+	level &= 0x7;
+	return level;
+}
+
 static int brightness_read(char *p)
 {
 	int len = 0;
-	u8 level;
+	int level = brightness_read_value(NULL);
 
-	if (!acpi_ec_read(brightness_offset, &level)) {
+	if (level < 0) {
 		len += sprintf(p + len, "level:\t\tunreadable\n");
 	} else {
-		len += sprintf(p + len, "level:\t\t%d\n", level & 0x7);
+		len += sprintf(p + len, "level:\t\t%d\n", level);
 		len += sprintf(p + len, "commands:\tup, down\n");
 		len += sprintf(p + len, "commands:\tlevel <level>"
 			       " (<level> is 0-7)\n");
@@ -1338,9 +1352,38 @@
 #define BRIGHTNESS_UP	4
 #define BRIGHTNESS_DOWN	5
 
+static int brightness_write_value(int value)
+{
+	int current_value = brightness_read_value(NULL);
+	int inc;
+	int cmos_cmd; 
+
+	value &= 7;
+
+	cmos_cmd = value > current_value ? BRIGHTNESS_UP : BRIGHTNESS_DOWN;
+
+	inc = value > current_value ? 1 : -1;
+
+	while (value != current_value) {
+		current_value += inc;
+
+		if (!cmos_eval(cmos_cmd))
+			return -EIO;
+		if (!acpi_ec_write(brightness_offset, current_value))
+			return -EIO;
+	}
+
+	return 0;
+}
+
+static int brightness_update_value(struct backlight_device *bd)
+{
+	int value = bd->props->brightness;
+	return brightness_write_value(value);
+}
+
 static int brightness_write(char *buf)
 {
-	int cmos_cmd, inc, i;
 	u8 level;
 	int new_level;
 	char *cmd;
@@ -1360,14 +1403,8 @@
 		} else
 			return -EINVAL;
 
-		cmos_cmd = new_level > level ? BRIGHTNESS_UP : BRIGHTNESS_DOWN;
-		inc = new_level > level ? 1 : -1;
-		for (i = level; i != new_level; i += inc) {
-			if (!cmos_eval(cmos_cmd))
-				return -EIO;
-			if (!acpi_ec_write(brightness_offset, i + inc))
-				return -EIO;
-		}
+		brightness_write_value(new_level);
+		
 	}
 
 	return 0;
@@ -1895,10 +1932,21 @@
 IBM_PARAM(volume);
 IBM_PARAM(fan);
 
+
+static struct backlight_properties ibmbl_data = {
+        .owner          = THIS_MODULE,
+        .get_brightness = brightness_read_value,
+        .update_status  = brightness_update_value,
+        .max_brightness = 7,
+};
+
 static void acpi_ibm_exit(void)
 {
 	int i;
 
+	if (ibm_backlight_device)
+		backlight_device_unregister(ibm_backlight_device);
+
 	for (i = ARRAY_SIZE(ibms) - 1; i >= 0; i--)
 		ibm_exit(&ibms[i]);
 
@@ -1966,6 +2014,13 @@
 		}
 	}
 
+	ibm_backlight_device = backlight_device_register ("ibm_bl", NULL,
+							  &ibmbl_data);
+        if (IS_ERR (ibm_backlight_device)) {
+		printk(KERN_ERR "Unable to register IBM backlight driver\n");
+		ibm_backlight_device = NULL;
+	}
+
 	return 0;
 }
 
diff -ur drivers/acpi.bak/Kconfig drivers/acpi/Kconfig
--- drivers/acpi.bak/Kconfig	2006-04-18 08:51:49 +0100
+++ a/drivers/acpi/Kconfig	2006-04-19 19:39:03 +0100
@@ -196,6 +196,7 @@
 config ACPI_IBM
 	tristate "IBM ThinkPad Laptop Extras"
 	depends on X86
+	select BACKLIGHT_DEVICE
 	---help---
 	  This is a Linux ACPI driver for the IBM ThinkPad laptops. It adds
 	  support for Fn-Fx key combinations, Bluetooth control, video

-- 
Matthew Garrett | mjg59@srcf.ucam.org

PATCH [3/3]: Provide generic backlight support in Toshiba ACPI driver

[Matthew Garrett]

Signed-off-by: Matthew Garrett <mjg59@srcf.ucam.org>

diff -ur drivers/acpi.bak/Kconfig drivers/acpi/Kconfig
--- drivers/acpi.bak/Kconfig	2006-04-18 08:51:49 +0100
+++ a/drivers/acpi/Kconfig	2006-04-19 19:37:08 +0100
@@ -220,6 +220,7 @@
 config ACPI_TOSHIBA
 	tristate "Toshiba Laptop Extras"
 	depends on X86
+	select BACKLIGHT_DEVICE
 	---help---
 	  This driver adds support for access to certain system settings
 	  on "legacy free" Toshiba laptops.  These laptops can be recognized by
diff -ur drivers/acpi.bak/toshiba_acpi.c drivers/acpi/toshiba_acpi.c
--- drivers/acpi.bak/toshiba_acpi.c	2006-04-03 04:22:10 +0100
+++ a/drivers/acpi/toshiba_acpi.c	2006-04-19 19:37:48 +0100
@@ -41,6 +41,7 @@
 #include <linux/init.h>
 #include <linux/types.h>
 #include <linux/proc_fs.h>
+#include <linux/backlight.h>
 #include <asm/uaccess.h>
 
 #include <acpi/acpi_drivers.h>
@@ -97,6 +98,8 @@
 #define HCI_VIDEO_OUT_CRT		0x2
 #define HCI_VIDEO_OUT_TV		0x4
 
+static struct backlight_device *tosh_backlight_device;
+
 /* utility
  */
 
@@ -289,6 +292,19 @@
 	return p;
 }
 
+static int tosh_get_brightness(struct backlight_device *bd)
+{
+	int brightness;
+	u32 hci_result;
+
+	hci_read1(HCI_LCD_BRIGHTNESS, &brightness, &hci_result);
+	if (hci_result == HCI_SUCCESS) {
+		brightness = brightness >> HCI_LCD_BRIGHTNESS_SHIFT;
+		return brightness;
+	} else
+		return 0;
+}
+
 static unsigned long write_lcd(const char *buffer, unsigned long count)
 {
 	int value;
@@ -307,6 +323,28 @@
 	return count;
 }
 
+static int tosh_set_brightness(int brightness)
+{
+	u32 hci_result;
+
+	if (brightness >= 0 && brightness < HCI_LCD_BRIGHTNESS_LEVELS) {
+		brightness= brightness << HCI_LCD_BRIGHTNESS_SHIFT;
+		hci_write1(HCI_LCD_BRIGHTNESS, brightness, &hci_result);
+		if (hci_result != HCI_SUCCESS)
+			return -EFAULT;
+	} else {
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int tosh_update_brightness(struct backlight_device *bd)
+{
+	int value = bd->props->brightness;
+	return tosh_set_brightness(value);
+}
+
 static char *read_video(char *p)
 {
 	u32 hci_result;
@@ -477,6 +515,13 @@
 	{NULL}
 };
 
+static struct backlight_properties toshbl_data = {
+	.owner          = THIS_MODULE,
+	.get_brightness = tosh_get_brightness,
+	.update_status  = tosh_update_brightness,
+	.max_brightness = HCI_LCD_BRIGHTNESS_LEVELS,
+};
+
 static acpi_status __init add_device(void)
 {
 	struct proc_dir_entry *proc;
@@ -546,6 +591,14 @@
 			remove_proc_entry(PROC_TOSHIBA, acpi_root_dir);
 	}
 
+	tosh_backlight_device = backlight_device_register ("tosh-bl", NULL,
+							   &toshbl_data);
+
+	if (IS_ERR (tosh_backlight_device)) {
+		printk("Failed to register Toshiba backlight device\n");
+		tosh_backlight_device = NULL;
+	}
+
 	return (ACPI_SUCCESS(status)) ? 0 : -ENODEV;
 }
 
@@ -556,6 +609,9 @@
 	if (toshiba_proc_dir)
 		remove_proc_entry(PROC_TOSHIBA, acpi_root_dir);
 
+	if (tosh_backlight_device) 
+		backlight_device_unregister(tosh_backlight_device);
+
 	return;
 }

-- 
Matthew Garrett | mjg59@srcf.ucam.org