drm/radeon/kms: add new radeon_info ioctl query for clock crystal freq

Needed for timer queries in the 3D driver.
Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@gmail.com>

drivers/gpu/drm/radeon/radeon_drv.c

@@ -48,7 +48,7 @@
  * - 2.5.0 - add get accel 2 to work around ddx breakage for evergreen
  * - 2.6.0 - add tiling config query (r6xx+), add initial HiZ support (r300->r500)
  *   2.7.0 - fixups for r600 2D tiling support. (no external ABI change), add eg dyn gpr regs
- *   2.8.0 - pageflip support, r500 US_FORMAT regs. r500 ARGB2101010 colorbuf, r300->r500 CMASK
+ *   2.8.0 - pageflip support, r500 US_FORMAT regs. r500 ARGB2101010 colorbuf, r300->r500 CMASK, clock crystal query
  */
 #define KMS_DRIVER_MAJOR	2
 #define KMS_DRIVER_MINOR	8

drivers/gpu/drm/radeon/radeon_kms.c

@@ -201,6 +201,10 @@ int radeon_info_ioctl(struct drm_device *dev, void *data, struct drm_file *filp)
 		}
 		radeon_set_filp_rights(dev, &rdev->cmask_filp, filp, &value);
 		break;
+	case RADEON_INFO_CLOCK_CRYSTAL_FREQ:
+		/* return clock value in KHz */
+		value = rdev->clock.spll.reference_freq * 10;
+		break;
 	default:
 		DRM_DEBUG_KMS("Invalid request %d\n", info->request);
 		return -EINVAL;

include/drm/radeon_drm.h

@@ -907,6 +907,7 @@ struct drm_radeon_cs {
 #define RADEON_INFO_TILING_CONFIG	0x06
 #define RADEON_INFO_WANT_HYPERZ		0x07
 #define RADEON_INFO_WANT_CMASK		0x08 /* get access to CMASK on r300 */
+#define RADEON_INFO_CLOCK_CRYSTAL_FREQ	0x09 /* clock crystal frequency */
 
 struct drm_radeon_info {
 	uint32_t		request;