[PATCH] acpi: add backlight support to the sony_acpi driver (v2)

[PATCH] acpi: add backlight support to the sony_acpi driver (v2)

[Alessandro Guido]

Enable the sony_acpi driver to use the backlight subsysyem for
adjusting the monitor brightness. Old way of changing the brightness will be
still available for compatibility with existing tools.

Signed-off-by: Alessandro Guido <alessandro.guido@gmail.com>
---

 Kconfig     |    1 +
 sony_acpi.c |   53 ++++++++++++++++++++++++++++++++++++++++++++++++-----
 2 files changed, 49 insertions(+), 5 deletions(-)

Index: linux-2.6.18/drivers/acpi/Kconfig
===================================================================
--- linux-2.6.18.orig/drivers/acpi/Kconfig
+++ linux-2.6.18/drivers/acpi/Kconfig
@@ -251,6 +251,7 @@ config ACPI_TOSHIBA
 config ACPI_SONY
 	tristate "Sony Laptop Extras"
 	depends on X86 && ACPI
+	select BACKLIGHT_CLASS_DEVICE
 	default m
 	  ---help---
 	  This mini-driver drives the ACPI SNC device present in the
Index: linux-2.6.18/drivers/acpi/sony_acpi.c
===================================================================
--- linux-2.6.18.orig/drivers/acpi/sony_acpi.c
+++ linux-2.6.18/drivers/acpi/sony_acpi.c
@@ -27,13 +27,19 @@
 #include <linux/moduleparam.h>
 #include <linux/init.h>
 #include <linux/types.h>
+#include <linux/backlight.h>
+#include <linux/err.h>
 #include <acpi/acpi_drivers.h>
 #include <acpi/acpi_bus.h>
 #include <asm/uaccess.h>
 
 #define ACPI_SNC_CLASS		"sony"
 #define ACPI_SNC_HID		"SNY5001"
-#define ACPI_SNC_DRIVER_NAME	"ACPI Sony Notebook Control Driver v0.2"
+#define ACPI_SNC_DRIVER_NAME	"ACPI Sony Notebook Control Driver v0.3"
+
+/* the device uses 1-based values, while the backlight subsystem uses
+   0-based values */
+#define SONY_MAX_BRIGHTNESS	8
 
 #define LOG_PFX			KERN_WARNING "sony_acpi: "
 
@@ -49,6 +55,16 @@ MODULE_PARM_DESC(debug, "set this to 1 (
 static acpi_handle sony_acpi_handle;
 static struct proc_dir_entry *sony_acpi_dir;
 
+static int sony_backlight_update_status(struct backlight_device *bd);
+static int sony_backlight_get_brightness(struct backlight_device *bd);
+static struct backlight_device *sony_backlight_device;
+static struct backlight_properties sony_backlight_properties = {
+	.owner		= THIS_MODULE,
+	.update_status	= sony_backlight_update_status,
+	.get_brightness	= sony_backlight_get_brightness,
+	.max_brightness	= SONY_MAX_BRIGHTNESS - 1,
+};
+
 static struct sony_acpi_value {
 	char			*name;	 /* name of the entry */
 	struct proc_dir_entry 	*proc;	 /* /proc entry */
@@ -65,7 +81,7 @@ static struct sony_acpi_value {
 		.acpiget	= "GBRT",
 		.acpiset	= "SBRT",
 		.min		= 1,
-		.max		= 8,
+		.max		= SONY_MAX_BRIGHTNESS,
 		.debug		= 0,
 	},
 	{
@@ -73,7 +89,7 @@ static struct sony_acpi_value {
 		.acpiget	= "GPBR",
 		.acpiset	= "SPBR",
 		.min		= 1,
-		.max		= 8,
+		.max		= SONY_MAX_BRIGHTNESS,
 		.debug		= 0,
 	},
 	{
@@ -276,6 +292,7 @@ static int sony_acpi_add(struct acpi_dev
 {
 	acpi_status status;
 	int result;
+	acpi_handle handle;
 	struct sony_acpi_value *item;
 
 	sony_acpi_handle = device->handle;
@@ -303,9 +320,15 @@ static int sony_acpi_add(struct acpi_dev
 		}
 	}
 
-	for (item = sony_acpi_values; item->name; ++item) {
-		acpi_handle handle;
+	if (ACPI_SUCCESS(acpi_get_handle(sony_acpi_handle, "GBRT", &handle))) {
+		sony_backlight_device = backlight_device_register("sony", NULL,
+					&sony_backlight_properties);
+	        if (IS_ERR(sony_backlight_device)) {
+        	        printk(LOG_PFX "unable to register backlight device\n");
+		}
+	}
 
+	for (item = sony_acpi_values; item->name; ++item) {
 		if (!debug && item->debug)
 			continue;
 
@@ -358,6 +381,9 @@ static int sony_acpi_remove(struct acpi_
 	acpi_status status;
 	struct sony_acpi_value *item;
 
+	if (sony_backlight_device)
+		backlight_device_unregister(sony_backlight_device);
+
 	if (debug) {
 		status = acpi_remove_notify_handler(sony_acpi_handle,
 						    ACPI_DEVICE_NOTIFY,
@@ -375,6 +401,23 @@ static int sony_acpi_remove(struct acpi_
 	return 0;
 }
 
+static int sony_backlight_update_status(struct backlight_device *bd)
+{
+	return acpi_callsetfunc(sony_acpi_handle, "SBRT",
+				bd->props->brightness + 1,
+				NULL);
+}
+
+static int sony_backlight_get_brightness(struct backlight_device *bd)
+{
+	int value;
+
+	if (acpi_callgetfunc(sony_acpi_handle, "GBRT", &value))
+		return 0;
+	/* brightness levels are 1-based, while backlight ones are 0-based */
+	return value - 1;
+}
+
 static struct acpi_driver sony_acpi_driver = {
 	.name	= ACPI_SNC_DRIVER_NAME,
 	.class	= ACPI_SNC_CLASS,

Re: [PATCH] acpi: add backlight support to the sony_acpi driver (v2)

[Pavel Machek]

Hi!

> Enable the sony_acpi driver to use the backlight subsysyem for
> adjusting the monitor brightness. Old way of changing the brightness will be
> still available for compatibility with existing tools.
> 
> Signed-off-by: Alessandro Guido <alessandro.guido@gmail.com>

Looks okay to me. We really want unified interface for backlight.

							Pavel
-- 
Thanks for all the (sleeping) penguins.

Re: [PATCH] acpi: add backlight support to the sony_acpi driver (v2)

[Henrique de Moraes Holschuh]

On Fri, 01 Dec 2006, Pavel Machek wrote:
> Looks okay to me. We really want unified interface for backlight.

Then I request some help to get
http://article.gmane.org/gmane.linux.acpi.devel/19792
merged.

Without it, the backlight interface becomes annoying on laptops.  Your
screen will be powered off when you remove the modules providing the
backlight interface.  This is not consistent with the needs of laptop
backlight devices, or with the behaviour the drivers had before the
backlight sysfs support was added.

-- 
  "One disk to rule them all, One disk to find them. One disk to bring
  them all and in the darkness grind them. In the Land of Redmond
  where the shadows lie." -- The Silicon Valley Tarot
  Henrique Holschuh

Re: [PATCH] acpi: add backlight support to the sony_acpi driver (v2)

[Pavel Machek]

Hi!

> > Looks okay to me. We really want unified interface for backlight.
> 
> Then I request some help to get
> http://article.gmane.org/gmane.linux.acpi.devel/19792
> merged.
> 
> Without it, the backlight interface becomes annoying on laptops.  Your
> screen will be powered off when you remove the modules providing the
> backlight interface.  This is not consistent with the needs of laptop
> backlight devices, or with the behaviour the drivers had before the
> backlight sysfs support was added.

Just retransmit it to akpm and list, and add acked-by headers with
people who said patch is okay... that included me IIRC.

-- 
Thanks for all the (sleeping) penguins.

Re: [PATCH] acpi: add backlight support to the sony_acpi driver (v2)

[James Simmons]

Its nice to see acpi moving to the backlight api. Will acpi also move to 
hwmon and led class support ?

On Sat, 2 Dec 2006, Pavel Machek wrote:

> Hi!
> 
> > > Looks okay to me. We really want unified interface for backlight.
> > 
> > Then I request some help to get
> > http://article.gmane.org/gmane.linux.acpi.devel/19792
> > merged.
> > 
> > Without it, the backlight interface becomes annoying on laptops.  Your
> > screen will be powered off when you remove the modules providing the
> > backlight interface.  This is not consistent with the needs of laptop
> > backlight devices, or with the behaviour the drivers had before the
> > backlight sysfs support was added.
> 
> Just retransmit it to akpm and list, and add acked-by headers with
> people who said patch is okay... that included me IIRC.
> 
> 

Re: [PATCH] acpi: add backlight support to the sony_acpi driver (v2)

[Pavel Machek]

Please don't top-post...

> Its nice to see acpi moving to the backlight api. Will acpi also move to 
> hwmon and led class support ?

It would be nice... ACPI does not drive many leds ... usually ... but
creating battery API based on hwmon and moving ACPI battery support to
that API would certainly be nice... and I believe it is ongoing work.
								Pavel

> > Hi!
> > 
> > > > Looks okay to me. We really want unified interface for backlight.
> > > 
> > > Then I request some help to get
> > > http://article.gmane.org/gmane.linux.acpi.devel/19792
> > > merged.
> > > 
> > > Without it, the backlight interface becomes annoying on laptops.  Your
> > > screen will be powered off when you remove the modules providing the
> > > backlight interface.  This is not consistent with the needs of laptop
> > > backlight devices, or with the behaviour the drivers had before the
> > > backlight sysfs support was added.
> > 
> > Just retransmit it to akpm and list, and add acked-by headers with
> > people who said patch is okay... that included me IIRC.
> > 
> > 

-- 
Thanks, Sharp!

Re: [PATCH] acpi: add backlight support to the sony_acpi driver (v2)

[Stefan Schmidt]

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Hello.

On Wed, 2006-12-06 at 19:54, Pavel Machek wrote:
> 
> Please don't top-post...
> 
> > Its nice to see acpi moving to the backlight api. Will acpi also move to 
> > hwmon and led class support ?
> 
> It would be nice... ACPI does not drive many leds ... usually ...

I work on led class support for ibm-acpi. It's on is way.

regards
Stefan Schmidt

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