ACPI / i915: replace open-coded _DSM code with helper functions

Use helper functions to simplify _DSM related code in i915 driver.

Function intel_dsm() is used to check functions supported by ACPI _DSM
method, but it has strange check for special value 0x80000002. After
digging into nouveau driver, I think the check is copied from nouveau
driver and is useless for i915 driver, so remove it.

Acked-by: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/gpu/drm/i915/intel_acpi.c b/drivers/gpu/drm/i915/intel_acpi.c
index dfff090..1bfac94 100644 (file)
--- a/drivers/gpu/drm/i915/intel_acpi.c
+++ b/drivers/gpu/drm/i915/intel_acpi.c
@@ -12,8 +12,6 @@
 #include "i915_drv.h"
 
 #define INTEL_DSM_REVISION_ID 1 /* For Calpella anyway... */
-
-#define INTEL_DSM_FN_SUPPORTED_FUNCTIONS 0 /* No args */
 #define INTEL_DSM_FN_PLATFORM_MUX_INFO 1 /* No args */
 
 static struct intel_dsm_priv {
@@ -28,61 +26,6 @@ static const u8 intel_dsm_guid[] = {
        0x0f, 0x13, 0x17, 0xb0, 0x1c, 0x2c
 };
 
-static int intel_dsm(acpi_handle handle, int func)
-{
-       struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
-       struct acpi_object_list input;
-       union acpi_object params[4];
-       union acpi_object *obj;
-       u32 result;
-       int ret = 0;
-
-       input.count = 4;
-       input.pointer = params;
-       params[0].type = ACPI_TYPE_BUFFER;
-       params[0].buffer.length = sizeof(intel_dsm_guid);
-       params[0].buffer.pointer = (char *)intel_dsm_guid;
-       params[1].type = ACPI_TYPE_INTEGER;
-       params[1].integer.value = INTEL_DSM_REVISION_ID;
-       params[2].type = ACPI_TYPE_INTEGER;
-       params[2].integer.value = func;
-       params[3].type = ACPI_TYPE_PACKAGE;
-       params[3].package.count = 0;
-       params[3].package.elements = NULL;
-
-       ret = acpi_evaluate_object(handle, "_DSM", &input, &output);
-       if (ret) {
-               DRM_DEBUG_DRIVER("failed to evaluate _DSM: %d\n", ret);
-               return ret;
-       }
-
-       obj = (union acpi_object *)output.pointer;
-
-       result = 0;
-       switch (obj->type) {
-       case ACPI_TYPE_INTEGER:
-               result = obj->integer.value;
-               break;
-
-       case ACPI_TYPE_BUFFER:
-               if (obj->buffer.length == 4) {
-                       result = (obj->buffer.pointer[0] |
-                               (obj->buffer.pointer[1] <<  8) |
-                               (obj->buffer.pointer[2] << 16) |
-                               (obj->buffer.pointer[3] << 24));
-                       break;
-               }
-       default:
-               ret = -EINVAL;
-               break;
-       }
-       if (result == 0x80000002)
-               ret = -ENODEV;
-
-       kfree(output.pointer);
-       return ret;
-}
-
 static char *intel_dsm_port_name(u8 id)
 {
        switch (id) {
@@ -137,83 +80,56 @@ static char *intel_dsm_mux_type(u8 type)
 
 static void intel_dsm_platform_mux_info(void)
 {
-       struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
-       struct acpi_object_list input;
-       union acpi_object params[4];
-       union acpi_object *pkg;
-       int i, ret;
-
-       input.count = 4;
-       input.pointer = params;
-       params[0].type = ACPI_TYPE_BUFFER;
-       params[0].buffer.length = sizeof(intel_dsm_guid);
-       params[0].buffer.pointer = (char *)intel_dsm_guid;
-       params[1].type = ACPI_TYPE_INTEGER;
-       params[1].integer.value = INTEL_DSM_REVISION_ID;
-       params[2].type = ACPI_TYPE_INTEGER;
-       params[2].integer.value = INTEL_DSM_FN_PLATFORM_MUX_INFO;
-       params[3].type = ACPI_TYPE_PACKAGE;
-       params[3].package.count = 0;
-       params[3].package.elements = NULL;
-
-       ret = acpi_evaluate_object(intel_dsm_priv.dhandle, "_DSM", &input,
-                                  &output);
-       if (ret) {
-               DRM_DEBUG_DRIVER("failed to evaluate _DSM: %d\n", ret);
-               goto out;
+       int i;
+       union acpi_object *pkg, *connector_count;
+
+       pkg = acpi_evaluate_dsm_typed(intel_dsm_priv.dhandle, intel_dsm_guid,
+                       INTEL_DSM_REVISION_ID, INTEL_DSM_FN_PLATFORM_MUX_INFO,
+                       NULL, ACPI_TYPE_PACKAGE);
+       if (!pkg) {
+               DRM_DEBUG_DRIVER("failed to evaluate _DSM\n");
+               return;
        }
 
-       pkg = (union acpi_object *)output.pointer;
-
-       if (pkg->type == ACPI_TYPE_PACKAGE) {
-               union acpi_object *connector_count = &pkg->package.elements[0];
-               DRM_DEBUG_DRIVER("MUX info connectors: %lld\n",
-                         (unsigned long long)connector_count->integer.value);
-               for (i = 1; i < pkg->package.count; i++) {
-                       union acpi_object *obj = &pkg->package.elements[i];
-                       union acpi_object *connector_id =
-                               &obj->package.elements[0];
-                       union acpi_object *info = &obj->package.elements[1];
-                       DRM_DEBUG_DRIVER("Connector id: 0x%016llx\n",
-                                 (unsigned long long)connector_id->integer.value);
-                       DRM_DEBUG_DRIVER("  port id: %s\n",
-                              intel_dsm_port_name(info->buffer.pointer[0]));
-                       DRM_DEBUG_DRIVER("  display mux info: %s\n",
-                              intel_dsm_mux_type(info->buffer.pointer[1]));
-                       DRM_DEBUG_DRIVER("  aux/dc mux info: %s\n",
-                              intel_dsm_mux_type(info->buffer.pointer[2]));
-                       DRM_DEBUG_DRIVER("  hpd mux info: %s\n",
-                              intel_dsm_mux_type(info->buffer.pointer[3]));
-               }
+       connector_count = &pkg->package.elements[0];
+       DRM_DEBUG_DRIVER("MUX info connectors: %lld\n",
+                 (unsigned long long)connector_count->integer.value);
+       for (i = 1; i < pkg->package.count; i++) {
+               union acpi_object *obj = &pkg->package.elements[i];
+               union acpi_object *connector_id = &obj->package.elements[0];
+               union acpi_object *info = &obj->package.elements[1];
+               DRM_DEBUG_DRIVER("Connector id: 0x%016llx\n",
+                         (unsigned long long)connector_id->integer.value);
+               DRM_DEBUG_DRIVER("  port id: %s\n",
+                      intel_dsm_port_name(info->buffer.pointer[0]));
+               DRM_DEBUG_DRIVER("  display mux info: %s\n",
+                      intel_dsm_mux_type(info->buffer.pointer[1]));
+               DRM_DEBUG_DRIVER("  aux/dc mux info: %s\n",
+                      intel_dsm_mux_type(info->buffer.pointer[2]));
+               DRM_DEBUG_DRIVER("  hpd mux info: %s\n",
+                      intel_dsm_mux_type(info->buffer.pointer[3]));
        }
 
-out:
-       kfree(output.pointer);
+       ACPI_FREE(pkg);
 }
 
 static bool intel_dsm_pci_probe(struct pci_dev *pdev)
 {
        acpi_handle dhandle;
-       int ret;
 
        dhandle = ACPI_HANDLE(&pdev->dev);
        if (!dhandle)
                return false;
 
-       if (!acpi_has_method(dhandle, "_DSM")) {
+       if (!acpi_check_dsm(dhandle, intel_dsm_guid, INTEL_DSM_REVISION_ID,
+                           1 << INTEL_DSM_FN_PLATFORM_MUX_INFO)) {
                DRM_DEBUG_KMS("no _DSM method for intel device\n");
                return false;
        }
 
-       ret = intel_dsm(dhandle, INTEL_DSM_FN_SUPPORTED_FUNCTIONS);
-       if (ret < 0) {
-               DRM_DEBUG_KMS("failed to get supported _DSM functions\n");
-               return false;
-       }
-
        intel_dsm_priv.dhandle = dhandle;
-
        intel_dsm_platform_mux_info();
+
        return true;
 }