[PATCH] platform samsung-q10: use ACPI instead of direct EC calls

From: Frederick van der Wyck
Date: Wed Jul 03 2013 - 17:13:17 EST


This patch changes the Samsung Q10 backlight driver to use ACPI methods (the same ones as triggered by the brightness up/down function keys) instead of direct EC calls. The advantage is that the brightness setting is not lost on shutdown.

Signed-off-by: Frederick van der Wyck <fvanderwyck@xxxxxxxxx>
---
drivers/platform/x86/Kconfig | 2 +-
drivers/platform/x86/samsung-q10.c | 77 ++++++++++++++++--------------------
2 files changed, 35 insertions(+), 44 deletions(-)

diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index 8577261..52aed6d 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -762,7 +762,7 @@ config INTEL_OAKTRAIL

config SAMSUNG_Q10
tristate "Samsung Q10 Extras"
- depends on SERIO_I8042
+ depends on ACPI
select BACKLIGHT_CLASS_DEVICE
---help---
This driver provides support for backlight control on Samsung Q10
diff --git a/drivers/platform/x86/samsung-q10.c b/drivers/platform/x86/samsung-q10.c
index 1a90b62..e7caaa3 100644
--- a/drivers/platform/x86/samsung-q10.c
+++ b/drivers/platform/x86/samsung-q10.c
@@ -14,16 +14,14 @@
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/backlight.h>
-#include <linux/i8042.h>
#include <linux/dmi.h>
+#include <acpi/acpi_drivers.h>

-#define SAMSUNGQ10_BL_MAX_INTENSITY 255
-#define SAMSUNGQ10_BL_DEFAULT_INTENSITY 185
+#define SAMSUNGQ10_BL_MAX_INTENSITY 7

-#define SAMSUNGQ10_BL_8042_CMD 0xbe
-#define SAMSUNGQ10_BL_8042_DATA { 0x89, 0x91 }
+#define EC_HID "PNP0C09"

-static int samsungq10_bl_brightness;
+static acpi_handle ec_handle;

static bool force;
module_param(force, bool, 0);
@@ -33,21 +31,26 @@ MODULE_PARM_DESC(force,
static int samsungq10_bl_set_intensity(struct backlight_device *bd)
{

- int brightness = bd->props.brightness;
- unsigned char c[3] = SAMSUNGQ10_BL_8042_DATA;
+ acpi_status status;
+ int i;

- c[2] = (unsigned char)brightness;
- i8042_lock_chip();
- i8042_command(c, (0x30 << 8) | SAMSUNGQ10_BL_8042_CMD);
- i8042_unlock_chip();
- samsungq10_bl_brightness = brightness;
+ for (i = 0; i < SAMSUNGQ10_BL_MAX_INTENSITY; i++) {
+ status = acpi_evaluate_object(ec_handle, "_Q63", NULL, NULL);
+ if (ACPI_FAILURE(status))
+ return -EIO;
+ }
+ for (i = 0; i < bd->props.brightness; i++) {
+ status = acpi_evaluate_object(ec_handle, "_Q64", NULL, NULL);
+ if (ACPI_FAILURE(status))
+ return -EIO;
+ }

return 0;
}

static int samsungq10_bl_get_intensity(struct backlight_device *bd)
{
- return samsungq10_bl_brightness;
+ return bd->props.brightness;
}

static const struct backlight_ops samsungq10_bl_ops = {
@@ -55,28 +58,6 @@ static const struct backlight_ops samsungq10_bl_ops = {
.update_status = samsungq10_bl_set_intensity,
};

-#ifdef CONFIG_PM_SLEEP
-static int samsungq10_suspend(struct device *dev)
-{
- return 0;
-}
-
-static int samsungq10_resume(struct device *dev)
-{
-
- struct backlight_device *bd = dev_get_drvdata(dev);
-
- samsungq10_bl_set_intensity(bd);
- return 0;
-}
-#else
-#define samsungq10_suspend NULL
-#define samsungq10_resume NULL
-#endif
-
-static SIMPLE_DEV_PM_OPS(samsungq10_pm_ops,
- samsungq10_suspend, samsungq10_resume);
-
static int samsungq10_probe(struct platform_device *pdev)
{

@@ -93,9 +74,6 @@ static int samsungq10_probe(struct platform_device *pdev)

platform_set_drvdata(pdev, bd);

- bd->props.brightness = SAMSUNGQ10_BL_DEFAULT_INTENSITY;
- samsungq10_bl_set_intensity(bd);
-
return 0;
}

@@ -104,9 +82,6 @@ static int samsungq10_remove(struct platform_device *pdev)

struct backlight_device *bd = platform_get_drvdata(pdev);

- bd->props.brightness = SAMSUNGQ10_BL_DEFAULT_INTENSITY;
- samsungq10_bl_set_intensity(bd);
-
backlight_device_unregister(bd);

return 0;
@@ -116,7 +91,6 @@ static struct platform_driver samsungq10_driver = {
.driver = {
.name = KBUILD_MODNAME,
.owner = THIS_MODULE,
- .pm = &samsungq10_pm_ops,
},
.probe = samsungq10_probe,
.remove = samsungq10_remove,
@@ -167,11 +141,28 @@ static struct dmi_system_id __initdata samsungq10_dmi_table[] = {
};
MODULE_DEVICE_TABLE(dmi, samsungq10_dmi_table);

+static acpi_status __init acpi_handle_locate_callback(acpi_handle handle,
+ u32 level, void *context, void **return_value)
+{
+ *(acpi_handle *)return_value = handle;
+
+ return AE_CTRL_TERMINATE;
+}
+
static int __init samsungq10_init(void)
{
+
+ acpi_status status;
+
if (!force && !dmi_check_system(samsungq10_dmi_table))
return -ENODEV;

+ status = acpi_get_devices(EC_HID, acpi_handle_locate_callback,
+ NULL, &ec_handle);
+
+ if (ACPI_FAILURE(status))
+ return -ENODEV;
+
samsungq10_device = platform_create_bundle(&samsungq10_driver,
samsungq10_probe,
NULL, 0, NULL, 0);
--
1.7.3.4

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