drm/radeon/rs780: implement get_current_sclk/mclk

Will be used for exposing current clocks via INFO ioctl.

Tested-by: Marek Olšák <[e-mail]>
Signed-off-by: Alex Deucher <[e-mail]>

drivers/gpu/drm/radeon/radeon_asic.c

···
 		.print_power_state = &rs780_dpm_print_power_state,
 		.debugfs_print_current_performance_level = &rs780_dpm_debugfs_print_current_performance_level,
 		.force_performance_level = &rs780_dpm_force_performance_level,
+		.get_current_sclk = &rs780_dpm_get_current_sclk,
+		.get_current_mclk = &rs780_dpm_get_current_mclk,
 	},
 	.pflip = {
 		.page_flip = &rs600_page_flip,

drivers/gpu/drm/radeon/radeon_asic.h

···
 						       struct seq_file *m);
 int rs780_dpm_force_performance_level(struct radeon_device *rdev,
 				      enum radeon_dpm_forced_level level);
+u32 rs780_dpm_get_current_sclk(struct radeon_device *rdev);
+u32 rs780_dpm_get_current_mclk(struct radeon_device *rdev);
 
 /*
  * rv770,rv730,rv710,rv740

drivers/gpu/drm/radeon/rs780_dpm.c

···
 			   ps->sclk_high, ps->max_voltage);
 }
 
+/* get the current sclk in 10 khz units */
+u32 rs780_dpm_get_current_sclk(struct radeon_device *rdev)
+{
+	u32 current_fb_div = RREG32(FVTHROT_STATUS_REG0) & CURRENT_FEEDBACK_DIV_MASK;
+	u32 func_cntl = RREG32(CG_SPLL_FUNC_CNTL);
+	u32 ref_div = ((func_cntl & SPLL_REF_DIV_MASK) >> SPLL_REF_DIV_SHIFT) + 1;
+	u32 post_div = ((func_cntl & SPLL_SW_HILEN_MASK) >> SPLL_SW_HILEN_SHIFT) + 1 +
+		((func_cntl & SPLL_SW_LOLEN_MASK) >> SPLL_SW_LOLEN_SHIFT) + 1;
+	u32 sclk = (rdev->clock.spll.reference_freq * current_fb_div) /
+		(post_div * ref_div);
+
+	return sclk;
+}
+
+/* get the current mclk in 10 khz units */
+u32 rs780_dpm_get_current_mclk(struct radeon_device *rdev)
+{
+	struct igp_power_info *pi = rs780_get_pi(rdev);
+
+	return pi->bootup_uma_clk;
+}
+
 int rs780_dpm_force_performance_level(struct radeon_device *rdev,
 				      enum radeon_dpm_forced_level level)
 {