drm/amdgpu: SI support for UVD clock control

Port functionality from the Radeon driver to support
UVD clock control.
Signed-off-by: Alex Jivin <alex.jivin@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/si.c

@@ -1267,12 +1267,6 @@ static u32 si_get_xclk(struct amdgpu_device *adev)
 	return reference_clock;
 }
 
-//xxx:not implemented
-static int si_set_uvd_clocks(struct amdgpu_device *adev, u32 vclk, u32 dclk)
-{
-	return 0;
-}
-
 static void si_flush_hdp(struct amdgpu_device *adev, struct amdgpu_ring *ring)
 {
 	if (!ring || !ring->funcs->emit_wreg) {
@@ -1428,6 +1422,234 @@ static uint64_t si_get_pcie_replay_count(struct amdgpu_device *adev)
 	return (nak_r + nak_g);
 }
 
+static int si_uvd_send_upll_ctlreq(struct amdgpu_device *adev,
+				   unsigned cg_upll_func_cntl)
+{
+	unsigned i;
+
+	/* Make sure UPLL_CTLREQ is deasserted */
+	WREG32_P(cg_upll_func_cntl, 0, ~UPLL_CTLREQ_MASK);
+
+	mdelay(10);
+
+	/* Assert UPLL_CTLREQ */
+	WREG32_P(cg_upll_func_cntl, UPLL_CTLREQ_MASK, ~UPLL_CTLREQ_MASK);
+
+	/* Wait for CTLACK and CTLACK2 to get asserted */
+	for (i = 0; i < SI_MAX_CTLACKS_ASSERTION_WAIT; ++i) {
+		uint32_t mask = UPLL_CTLACK_MASK | UPLL_CTLACK2_MASK;
+
+		if ((RREG32(cg_upll_func_cntl) & mask) == mask)
+			break;
+		mdelay(10);
+	}
+
+	/* Deassert UPLL_CTLREQ */
+	WREG32_P(cg_upll_func_cntl, 0, ~UPLL_CTLREQ_MASK);
+
+	if (i == SI_MAX_CTLACKS_ASSERTION_WAIT) {
+		DRM_ERROR("Timeout setting UVD clocks!\n");
+		return -ETIMEDOUT;
+	}
+
+	return 0;
+}
+
+static unsigned si_uvd_calc_upll_post_div(unsigned vco_freq,
+					  unsigned target_freq,
+					  unsigned pd_min,
+					  unsigned pd_even)
+{
+	unsigned post_div = vco_freq / target_freq;
+
+	/* Adjust to post divider minimum value */
+	if (post_div < pd_min)
+		post_div = pd_min;
+
+	/* We alway need a frequency less than or equal the target */
+	if ((vco_freq / post_div) > target_freq)
+		post_div += 1;
+
+	/* Post dividers above a certain value must be even */
+	if (post_div > pd_even && post_div % 2)
+		post_div += 1;
+
+	return post_div;
+}
+
+/**
+ * si_calc_upll_dividers - calc UPLL clock dividers
+ *
+ * @adev: amdgpu_device pointer
+ * @vclk: wanted VCLK
+ * @dclk: wanted DCLK
+ * @vco_min: minimum VCO frequency
+ * @vco_max: maximum VCO frequency
+ * @fb_factor: factor to multiply vco freq with
+ * @fb_mask: limit and bitmask for feedback divider
+ * @pd_min: post divider minimum
+ * @pd_max: post divider maximum
+ * @pd_even: post divider must be even above this value
+ * @optimal_fb_div: resulting feedback divider
+ * @optimal_vclk_div: resulting vclk post divider
+ * @optimal_dclk_div: resulting dclk post divider
+ *
+ * Calculate dividers for UVDs UPLL (except APUs).
+ * Returns zero on success; -EINVAL on error.
+ */
+static int si_calc_upll_dividers(struct amdgpu_device *adev,
+				 unsigned vclk, unsigned dclk,
+				 unsigned vco_min, unsigned vco_max,
+				 unsigned fb_factor, unsigned fb_mask,
+				 unsigned pd_min, unsigned pd_max,
+				 unsigned pd_even,
+				 unsigned *optimal_fb_div,
+				 unsigned *optimal_vclk_div,
+				 unsigned *optimal_dclk_div)
+{
+	unsigned vco_freq, ref_freq = adev->clock.spll.reference_freq;
+
+	/* Start off with something large */
+	unsigned optimal_score = ~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 += 100) {
+		uint64_t fb_div = (uint64_t)vco_freq * fb_factor;
+		unsigned vclk_div, dclk_div, score;
+
+		do_div(fb_div, ref_freq);
+
+		/* fb div out of range ? */
+		if (fb_div > fb_mask)
+			break; /* It can oly get worse */
+
+		fb_div &= fb_mask;
+
+		/* Calc vclk divider with current vco freq */
+		vclk_div = si_uvd_calc_upll_post_div(vco_freq, vclk,
+						     pd_min, pd_even);
+		if (vclk_div > pd_max)
+			break; /* vco is too big, it has to stop */
+
+		/* Calc dclk divider with current vco freq */
+		dclk_div = si_uvd_calc_upll_post_div(vco_freq, dclk,
+						     pd_min, pd_even);
+		if (dclk_div > pd_max)
+			break; /* vco is too big, it has to stop */
+
+		/* Calc score with current vco freq */
+		score = vclk - (vco_freq / vclk_div) + dclk - (vco_freq / dclk_div);
+
+		/* Determine if this vco setting is better than current optimal settings */
+		if (score < optimal_score) {
+			*optimal_fb_div = fb_div;
+			*optimal_vclk_div = vclk_div;
+			*optimal_dclk_div = dclk_div;
+			optimal_score = score;
+			if (optimal_score == 0)
+				break; /* It can't get better than this */
+		}
+	}
+
+	/* Did we found a valid setup ? */
+	if (optimal_score == ~0)
+		return -EINVAL;
+
+	return 0;
+}
+
+static int si_set_uvd_clocks(struct amdgpu_device *adev, u32 vclk, u32 dclk)
+{
+	unsigned fb_div = 0, vclk_div = 0, dclk_div = 0;
+	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 */
+		return 0;
+	}
+
+	r = si_calc_upll_dividers(adev, vclk, dclk, 125000, 250000,
+				  16384, 0x03FFFFFF, 0, 128, 5,
+				  &fb_div, &vclk_div, &dclk_div);
+	if (r)
+		return r;
+
+	/* Set RESET_ANTI_MUX to 0 */
+	WREG32_P(CG_UPLL_FUNC_CNTL_5, 0, ~RESET_ANTI_MUX_MASK);
+
+	/* Set VCO_MODE to 1 */
+	WREG32_P(CG_UPLL_FUNC_CNTL, UPLL_VCO_MODE_MASK, ~UPLL_VCO_MODE_MASK);
+
+	/* Disable sleep mode */
+	WREG32_P(CG_UPLL_FUNC_CNTL, 0, ~UPLL_SLEEP_MASK);
+
+	/* Deassert UPLL_RESET */
+	WREG32_P(CG_UPLL_FUNC_CNTL, 0, ~UPLL_RESET_MASK);
+
+	mdelay(1);
+
+	r = si_uvd_send_upll_ctlreq(adev, CG_UPLL_FUNC_CNTL);
+	if (r)
+		return r;
+
+	/* Assert UPLL_RESET again */
+	WREG32_P(CG_UPLL_FUNC_CNTL, UPLL_RESET_MASK, ~UPLL_RESET_MASK);
+
+	/* Disable spread spectrum. */
+	WREG32_P(CG_UPLL_SPREAD_SPECTRUM, 0, ~SSEN_MASK);
+
+	/* Set feedback divider */
+	WREG32_P(CG_UPLL_FUNC_CNTL_3, UPLL_FB_DIV(fb_div), ~UPLL_FB_DIV_MASK);
+
+	/* Set ref divider to 0 */
+	WREG32_P(CG_UPLL_FUNC_CNTL, 0, ~UPLL_REF_DIV_MASK);
+
+	if (fb_div < 307200)
+		WREG32_P(CG_UPLL_FUNC_CNTL_4, 0, ~UPLL_SPARE_ISPARE9);
+	else
+		WREG32_P(CG_UPLL_FUNC_CNTL_4,
+			 UPLL_SPARE_ISPARE9,
+			 ~UPLL_SPARE_ISPARE9);
+
+	/* Set PDIV_A and PDIV_B */
+	WREG32_P(CG_UPLL_FUNC_CNTL_2,
+		 UPLL_PDIV_A(vclk_div) | UPLL_PDIV_B(dclk_div),
+		 ~(UPLL_PDIV_A_MASK | UPLL_PDIV_B_MASK));
+
+	/* Give the PLL some time to settle */
+	mdelay(15);
+
+	/* Deassert PLL_RESET */
+	WREG32_P(CG_UPLL_FUNC_CNTL, 0, ~UPLL_RESET_MASK);
+
+	mdelay(15);
+
+	/* Switch from bypass mode to normal mode */
+	WREG32_P(CG_UPLL_FUNC_CNTL, 0, ~UPLL_BYPASS_EN_MASK);
+
+	r = si_uvd_send_upll_ctlreq(adev, CG_UPLL_FUNC_CNTL);
+	if (r)
+		return r;
+
+	/* Switch VCLK and DCLK selection */
+	WREG32_P(CG_UPLL_FUNC_CNTL_2,
+		 VCLK_SRC_SEL(2) | DCLK_SRC_SEL(2),
+		 ~(VCLK_SRC_SEL_MASK | DCLK_SRC_SEL_MASK));
+
+	mdelay(100);
+
+	return 0;
+}
+
 static const struct amdgpu_asic_funcs si_asic_funcs =
 {
 	.read_disabled_bios = &si_read_disabled_bios,

drivers/gpu/drm/amd/amdgpu/sid.h

@@ -47,6 +47,7 @@
 #define SI_MAX_LDS_NUM           	0xFFFF
 #define SI_MAX_TCC               	16
 #define SI_MAX_TCC_MASK          	0xFFFF
+#define SI_MAX_CTLACKS_ASSERTION_WAIT   100
 
 #define AMDGPU_NUM_OF_VMIDS 		8