drm/radeon: put UVD PLLs in bypass mode

Just power down the PLL when we get a VCLK or DCLK of zero.
Enabling the bypass mode early should also allow us to
switch UVD clocks on the fly.

Signed-off-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/radeon/evergreen.c

@@ -189,6 +189,20 @@ int evergreen_set_uvd_clocks(struct radeon_device *rdev, u32 vclk, u32 dclk)
 	unsigned vco_freq;
 	int r;
 
+	/* bypass vclk and dclk with bclk */
+	WREG32_P(CG_UPLL_FUNC_CNTL_2,
+		VCLK_SRC_SEL(1) | DCLK_SRC_SEL(1),
+		~(VCLK_SRC_SEL_MASK | DCLK_SRC_SEL_MASK));
+
+	/* put PLL in bypass mode */
+	WREG32_P(CG_UPLL_FUNC_CNTL, UPLL_BYPASS_EN_MASK, ~UPLL_BYPASS_EN_MASK);
+
+	if (!vclk || !dclk) {
+		/* keep the Bypass mode, put PLL to sleep */
+		WREG32_P(CG_UPLL_FUNC_CNTL, UPLL_SLEEP_MASK, ~UPLL_SLEEP_MASK);
+		return 0;
+	}
+
 	/* loop through vco from low to high */
 	for (vco_freq = 125000; vco_freq <= 250000; vco_freq += 100) {
 		unsigned fb_div = vco_freq / rdev->clock.spll.reference_freq * 16384;
@@ -236,14 +250,6 @@ int evergreen_set_uvd_clocks(struct radeon_device *rdev, u32 vclk, u32 dclk)
 
 	mdelay(1);
 
-	/* bypass vclk and dclk with bclk */
-	WREG32_P(CG_UPLL_FUNC_CNTL_2,
-		VCLK_SRC_SEL(1) | DCLK_SRC_SEL(1),
-		~(VCLK_SRC_SEL_MASK | DCLK_SRC_SEL_MASK));
-
-	/* put PLL in bypass mode */
-	WREG32_P(CG_UPLL_FUNC_CNTL, UPLL_BYPASS_EN_MASK, ~UPLL_BYPASS_EN_MASK);
-
 	r = evergreen_uvd_send_upll_ctlreq(rdev);
 	if (r)
 		return r;

drivers/gpu/drm/radeon/rv770.c

@@ -100,6 +100,17 @@ int rv770_set_uvd_clocks(struct radeon_device *rdev, u32 vclk, u32 dclk)
 	if (rdev->family == CHIP_RV740)
 		return evergreen_set_uvd_clocks(rdev, vclk, dclk);
 
+	/* bypass vclk and dclk with bclk */
+	WREG32_P(CG_UPLL_FUNC_CNTL_2,
+		 VCLK_SRC_SEL(1) | DCLK_SRC_SEL(1),
+		 ~(VCLK_SRC_SEL_MASK | DCLK_SRC_SEL_MASK));
+
+	if (!vclk || !dclk) {
+		/* keep the Bypass mode, put PLL to sleep */
+		WREG32_P(CG_UPLL_FUNC_CNTL, UPLL_SLEEP_MASK, ~UPLL_SLEEP_MASK);
+		return 0;
+	}
+
 	/* loop through vco from low to high */
 	vco_min = max(max(vco_min, vclk), dclk);
 	for (vco_freq = vco_min; vco_freq <= vco_max; vco_freq += 500) {
@@ -139,16 +150,11 @@ int rv770_set_uvd_clocks(struct radeon_device *rdev, u32 vclk, u32 dclk)
 		}
 	}
 
-	/* bypass vclk and dclk with bclk */
-	WREG32_P(CG_UPLL_FUNC_CNTL_2,
-		 VCLK_SRC_SEL(1) | DCLK_SRC_SEL(1),
-		 ~(VCLK_SRC_SEL_MASK | DCLK_SRC_SEL_MASK));
-
 	/* set UPLL_FB_DIV to 0x50000 */
 	WREG32_P(CG_UPLL_FUNC_CNTL_3, UPLL_FB_DIV(0x50000), ~UPLL_FB_DIV_MASK);
 
-	/* deassert UPLL_RESET */
-	WREG32_P(CG_UPLL_FUNC_CNTL, 0, ~UPLL_RESET_MASK);
+	/* deassert UPLL_RESET and UPLL_SLEEP */
+	WREG32_P(CG_UPLL_FUNC_CNTL, 0, ~(UPLL_RESET_MASK | UPLL_SLEEP_MASK));
 
 	/* assert BYPASS EN and FB_DIV[0] <- ??? why? */
 	WREG32_P(CG_UPLL_FUNC_CNTL, UPLL_BYPASS_EN_MASK, ~UPLL_BYPASS_EN_MASK);

drivers/gpu/drm/radeon/si.c

@@ -4680,6 +4680,20 @@ int si_set_uvd_clocks(struct radeon_device *rdev, u32 vclk, u32 dclk)
 	unsigned vco_freq;
 	int r;
 
+	/* bypass vclk and dclk with bclk */
+	WREG32_P(CG_UPLL_FUNC_CNTL_2,
+		VCLK_SRC_SEL(1) | DCLK_SRC_SEL(1),
+		~(VCLK_SRC_SEL_MASK | DCLK_SRC_SEL_MASK));
+
+	/* put PLL in bypass mode */
+	WREG32_P(CG_UPLL_FUNC_CNTL, UPLL_BYPASS_EN_MASK, ~UPLL_BYPASS_EN_MASK);
+
+	if (!vclk || !dclk) {
+		/* keep the Bypass mode, put PLL to sleep */
+		WREG32_P(CG_UPLL_FUNC_CNTL, UPLL_SLEEP_MASK, ~UPLL_SLEEP_MASK);
+		return 0;
+	}
+
 	/* loop through vco from low to high */
 	for (vco_freq = 125000; vco_freq <= 250000; vco_freq += 100) {
 		unsigned fb_div = vco_freq / rdev->clock.spll.reference_freq * 16384;
@@ -4730,14 +4744,6 @@ int si_set_uvd_clocks(struct radeon_device *rdev, u32 vclk, u32 dclk)
 
 	mdelay(1);
 
-	/* bypass vclk and dclk with bclk */
-	WREG32_P(CG_UPLL_FUNC_CNTL_2,
-		VCLK_SRC_SEL(1) | DCLK_SRC_SEL(1),
-		~(VCLK_SRC_SEL_MASK | DCLK_SRC_SEL_MASK));
-
-	/* put PLL in bypass mode */
-	WREG32_P(CG_UPLL_FUNC_CNTL, UPLL_BYPASS_EN_MASK, ~UPLL_BYPASS_EN_MASK);
-
 	r = si_uvd_send_upll_ctlreq(rdev);
 	if (r)
 		return r;