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

From: Alessandro Guido
Date: Mon Nov 27 2006 - 11:43:39 EST


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@xxxxxxxxx>
---

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,
-
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