ACPI: Add a generic API for _OSC -v2

v2->v1:
.improve debug info as suggedted by Bjorn,Kenji
.API is using uuid string as suggested by Alexey

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>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 122 insertions, 0 deletions

diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
index 741191524353..12240be58f27 100644
--- a/drivers/acpi/bus.c
+++ b/drivers/acpi/bus.c
@@ -344,6 +344,128 @@ bool acpi_bus_can_wakeup(acpi_handle handle)
 
 EXPORT_SYMBOL(acpi_bus_can_wakeup);
 
+static void acpi_print_osc_error(acpi_handle handle,
+        struct acpi_osc_context *context, char *error)
+{
+        struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER};
+        int i;
+
+        if (ACPI_FAILURE(acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer)))
+                printk(KERN_DEBUG "%s\n", error);
+        else {
+                printk(KERN_DEBUG "%s:%s\n", (char *)buffer.pointer, error);
+                kfree(buffer.pointer);
+        }
+        printk(KERN_DEBUG"_OSC request data:");
+        for (i = 0; i < context->cap.length; i += sizeof(u32))
+                printk("%x ", *((u32 *)(context->cap.pointer + i)));
+        printk("\n");
+}
+
+static u8 hex_val(unsigned char c)
+{
+        return isdigit(c) ? c - '0' : toupper(c) - 'A' + 10;
+}
+
+static acpi_status acpi_str_to_uuid(char *str, u8 *uuid)
+{
+        int i;
+        static int opc_map_to_uuid[16] = {6, 4, 2, 0, 11, 9, 16, 14, 19, 21,
+                24, 26, 28, 30, 32, 34};
+
+        if (strlen(str) != 36)
+                return AE_BAD_PARAMETER;
+        for (i = 0; i < 36; i++) {
+                if (i == 8 || i == 13 || i == 18 || i == 23) {
+                        if (str[i] != '-')
+                                return AE_BAD_PARAMETER;
+                } else if (!isxdigit(str[i]))
+                        return AE_BAD_PARAMETER;
+        }
+        for (i = 0; i < 16; i++) {
+                uuid[i] = hex_val(str[opc_map_to_uuid[i]]) << 4;
+                uuid[i] |= hex_val(str[opc_map_to_uuid[i] + 1]);
+        }
+        return AE_OK;
+}
+
+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;
+        u8 uuid[16];
+        u32 errors;
+
+        if (!context)
+                return AE_ERROR;
+        if (ACPI_FAILURE(acpi_str_to_uuid(context->uuid_str, uuid)))
+                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     = 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) {
+                acpi_print_osc_error(handle, context,
+                        "_OSC evaluation returned wrong type");
+                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)
+                        acpi_print_osc_error(handle, context,
+                                "_OSC request failed");
+                if (errors & OSC_INVALID_UUID_ERROR)
+                        acpi_print_osc_error(handle, context,
+                                "_OSC invalid UUID");
+                if (errors & OSC_INVALID_REVISION_ERROR)
+                        acpi_print_osc_error(handle, context,
+                                "_OSC invalid revision");
+                if (errors & OSC_CAPABILITIES_MASK_ERROR) {
+                        if (((u32 *)context->cap.pointer)[OSC_QUERY_TYPE]
+                            & OSC_QUERY_ENABLE)
+                                goto out_success;
+                        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
    -------------------------------------------------------------------------- */