[PATCH 1/3] Add a generic API for _OSC

[Shaohua Li <shaohua.li@intel.com>]

Add an API to execute _OSC. A lot of devices can have this method, so add a
generic API.

Signed-off-by: Shaohua Li <shaohua.li@intel.com>
---
 drivers/acpi/bus.c   |   72 +++++++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/acpi.h |    9 ++++++
 2 files changed, 81 insertions(+)

Index: linux/drivers/acpi/bus.c
===================================================================
--- linux.orig/drivers/acpi/bus.c	2009-10-27 13:50:24.000000000 +0800
+++ linux/drivers/acpi/bus.c	2009-10-27 14:02:30.000000000 +0800
@@ -344,6 +344,78 @@ bool acpi_bus_can_wakeup(acpi_handle han
 
 EXPORT_SYMBOL(acpi_bus_can_wakeup);
 
+acpi_status acpi_run_osc(acpi_handle handle, struct acpi_osc_context *context)
+{
+	acpi_status status;
+	struct acpi_object_list input;
+	union acpi_object in_params[4];
+	union acpi_object *out_obj;
+	u32 errors;
+
+	if (!context)
+		return AE_ERROR;
+	context->ret.length = ACPI_ALLOCATE_BUFFER;
+	context->ret.pointer = NULL;
+
+	/* Setting up input parameters */
+	input.count = 4;
+	input.pointer = in_params;
+	in_params[0].type 		= ACPI_TYPE_BUFFER;
+	in_params[0].buffer.length 	= 16;
+	in_params[0].buffer.pointer	= context->uuid;
+	in_params[1].type 		= ACPI_TYPE_INTEGER;
+	in_params[1].integer.value 	= context->rev;
+	in_params[2].type 		= ACPI_TYPE_INTEGER;
+	in_params[2].integer.value	= context->cap.length/sizeof(u32);
+	in_params[3].type		= ACPI_TYPE_BUFFER;
+	in_params[3].buffer.length 	= context->cap.length;
+	in_params[3].buffer.pointer 	= context->cap.pointer;
+
+	status = acpi_evaluate_object(handle, "_OSC", &input, &context->ret);
+	if (ACPI_FAILURE(status))
+		return status;
+
+	/* return buffer should have the same length as cap buffer */
+	if (context->ret.length != context->cap.length)
+		return AE_NULL_OBJECT;
+
+	out_obj = context->ret.pointer;
+	if (out_obj->type != ACPI_TYPE_BUFFER) {
+		printk(KERN_DEBUG "_OSC evaluation returned wrong type\n");
+		status = AE_TYPE;
+		goto out_kfree;
+	}
+	/* Need to ignore the bit0 in result code */
+	errors = *((u32 *)out_obj->buffer.pointer) & ~(1 << 0);
+	if (errors) {
+		if (errors & OSC_REQUEST_ERROR)
+			printk(KERN_DEBUG "_OSC request failed\n");
+		if (errors & OSC_INVALID_UUID_ERROR)
+			printk(KERN_DEBUG "_OSC invalid UUID\n");
+		if (errors & OSC_INVALID_REVISION_ERROR)
+			printk(KERN_DEBUG "_OSC invalid revision\n");
+		if (errors & OSC_CAPABILITIES_MASK_ERROR) {
+			if (((u32 *)context->cap.pointer)[OSC_QUERY_TYPE]
+			    & OSC_QUERY_ENABLE)
+				goto out_success;
+			printk(KERN_DEBUG
+			       "Firmware did not grant requested _OSC control\n");
+			status = AE_SUPPORT;
+			goto out_kfree;
+		}
+		status = AE_ERROR;
+		goto out_kfree;
+	}
+out_success:
+	return AE_OK;
+
+out_kfree:
+	kfree(context->ret.pointer);
+	context->ret.pointer = NULL;
+	return status;
+}
+EXPORT_SYMBOL(acpi_run_osc);
+
 /* --------------------------------------------------------------------------
                                 Event Management
    -------------------------------------------------------------------------- */
Index: linux/include/linux/acpi.h
===================================================================
--- linux.orig/include/linux/acpi.h	2009-10-27 13:50:24.000000000 +0800
+++ linux/include/linux/acpi.h	2009-10-27 13:50:35.000000000 +0800
@@ -253,6 +253,13 @@ void __init acpi_old_suspend_ordering(vo
 void __init acpi_s4_no_nvs(void);
 #endif /* CONFIG_PM_SLEEP */
 
+struct acpi_osc_context {
+	u8 *uuid;
+	int rev;
+	struct acpi_buffer cap; /* arg2/arg3 */
+	struct acpi_buffer ret; /* free by caller if success */
+};
+
 #define OSC_QUERY_TYPE			0
 #define OSC_SUPPORT_TYPE 		1
 #define OSC_CONTROL_TYPE		2
@@ -265,6 +272,8 @@ void __init acpi_s4_no_nvs(void);
 #define OSC_INVALID_REVISION_ERROR	8
 #define OSC_CAPABILITIES_MASK_ERROR	16
 
+acpi_status acpi_run_osc(acpi_handle handle, struct acpi_osc_context *context);
+
 /* _OSC DW1 Definition (OS Support Fields) */
 #define OSC_EXT_PCI_CONFIG_SUPPORT		1
 #define OSC_ACTIVE_STATE_PWR_SUPPORT 		2