[Intel-gfx] [PATCH 2/2] drm/i915/hdmi: C20 computed PLL frequencies

Gustavo Sousa gustavo.sousa at intel.com
Mon May 8 13:25:03 UTC 2023


Quoting Clint Taylor (2023-05-05 15:46:40)
>Use algorithm to generate HDMI C20 PLL clock frequencies.
>
>BSPEC: 64568
>Cc: Radhakrishna Sripada <radhakrishna.sripada at intel.com>
>Cc: Mika Kahola <mika.kahola at intel.com>
>Cc: Anusha Srivatsa <anusha.srivatsa at intel.com>
>Cc: Gustavo Sousa <gustavo.sousa at intel.com>
>Signed-off-by: Clint Taylor <clinton.a.taylor at intel.com>

Reviewed-by: Gustavo Sousa <gustavo.sousa at intel.com>

>---
> drivers/gpu/drm/i915/display/intel_cx0_phy.c  | 89 +++++++++++++++++--
> .../gpu/drm/i915/display/intel_cx0_phy_regs.h | 53 +++++++++++
> 2 files changed, 136 insertions(+), 6 deletions(-)
>
>diff --git a/drivers/gpu/drm/i915/display/intel_cx0_phy.c b/drivers/gpu/drm/i915/display/intel_cx0_phy.c
>index d94127e7448b..fb5599ffca81 100644
>--- a/drivers/gpu/drm/i915/display/intel_cx0_phy.c
>+++ b/drivers/gpu/drm/i915/display/intel_cx0_phy.c
>@@ -3,6 +3,8 @@
>  * Copyright © 2023 Intel Corporation
>  */
> 
>+#include <linux/log2.h>
>+#include <linux/math64.h>
> #include "i915_reg.h"
> #include "intel_cx0_phy.h"
> #include "intel_cx0_phy_regs.h"
>@@ -1901,6 +1903,74 @@ void intel_c10pll_dump_hw_state(struct drm_i915_private *i915,
>                            i + 2, hw_state->pll[i + 2], i + 3, hw_state->pll[i + 3]);
> }
> 
>+static int intel_c20_compute_hdmi_tmds_pll(u64 pixel_clock, struct intel_c20pll_state *pll_state)
>+{
>+  u64 datarate;
>+  u64 mpll_tx_clk_div;
>+  u64 vco_freq_shift;
>+  u64 vco_freq;
>+  u64 multiplier;
>+  u64 mpll_multiplier;
>+  u64 mpll_fracn_quot;
>+  u64 mpll_fracn_rem;
>+  u8  mpllb_ana_freq_vco;
>+  u8  mpll_div_multiplier;
>+
>+  if (pixel_clock < 25175 || pixel_clock > 600000)
>+          return -EINVAL;
>+
>+  datarate = ((u64)pixel_clock * 1000) * 10;
>+  mpll_tx_clk_div = ilog2(div64_u64((u64)CLOCK_9999MHZ, (u64)datarate));
>+  vco_freq_shift = ilog2(div64_u64((u64)CLOCK_4999MHZ * (u64)256, (u64)datarate));
>+  vco_freq = (datarate << vco_freq_shift) >> 8;
>+  multiplier = div64_u64((vco_freq << 28), (REFCLK_38_4_MHZ >> 4));
>+  mpll_multiplier = 2 * (multiplier >> 32);
>+
>+  mpll_fracn_quot = (multiplier >> 16) & 0xFFFF;
>+  mpll_fracn_rem  = multiplier & 0xFFFF;
>+
>+  mpll_div_multiplier = min_t(u8, div64_u64((vco_freq * 16 + (datarate >> 1)), datarate), 255);
>+
>+  if (vco_freq <= DATARATE_3000000000)
>+          mpllb_ana_freq_vco = MPLLB_ANA_FREQ_VCO_3;
>+  else if (vco_freq <= DATARATE_3500000000)
>+          mpllb_ana_freq_vco = MPLLB_ANA_FREQ_VCO_2;
>+  else if (vco_freq <= DATARATE_4000000000)
>+          mpllb_ana_freq_vco = MPLLB_ANA_FREQ_VCO_1;
>+  else
>+          mpllb_ana_freq_vco = MPLLB_ANA_FREQ_VCO_0;
>+
>+  pll_state->link_bit_rate        = pixel_clock;
>+  pll_state->clock        = pixel_clock;
>+  pll_state->tx[0]        = 0xbe88;
>+  pll_state->tx[1]        = 0x9800;
>+  pll_state->tx[2]        = 0x0000;
>+  pll_state->cmn[0]       = 0x0500;
>+  pll_state->cmn[1]       = 0x0005;
>+  pll_state->cmn[2]       = 0x0000;
>+  pll_state->cmn[3]       = 0x0000;
>+  pll_state->mpllb[0]     = (MPLL_TX_CLK_DIV(mpll_tx_clk_div) |
>+                             MPLL_MULTIPLIER(mpll_multiplier));
>+  pll_state->mpllb[1]     = (CAL_DAC_CODE(CAL_DAC_CODE_31) |
>+                             WORD_CLK_DIV |
>+                             MPLL_DIV_MULTIPLIER(mpll_div_multiplier));
>+  pll_state->mpllb[2]     = (MPLLB_ANA_FREQ_VCO(mpllb_ana_freq_vco) |
>+                             CP_PROP(CP_PROP_20) |
>+                             CP_INT(CP_INT_6));
>+  pll_state->mpllb[3]     = (V2I(V2I_2) |
>+                             CP_PROP_GS(CP_PROP_GS_30) |
>+                             CP_INT_GS(CP_INT_GS_28));
>+  pll_state->mpllb[4]     = 0x0000;
>+  pll_state->mpllb[5]     = 0x0000;
>+  pll_state->mpllb[6]     = (C20_MPLLB_FRACEN | SSC_UP_SPREAD);
>+  pll_state->mpllb[7]     = MPLL_FRACN_DEN;
>+  pll_state->mpllb[8]     = mpll_fracn_quot;
>+  pll_state->mpllb[9]     = mpll_fracn_rem;
>+  pll_state->mpllb[10]    = HDMI_DIV(HDMI_DIV_1);
>+
>+  return 0;
>+}
>+
> static int intel_c20_phy_check_hdmi_link_rate(int clock)
> {
>        const struct intel_c20pll_state * const *tables = mtl_c20_hdmi_tables;
>@@ -1911,6 +1981,9 @@ static int intel_c20_phy_check_hdmi_link_rate(int clock)
>                        return MODE_OK;
>        }
> 
>+  if (clock >= 25175 && clock <= 594000)
>+          return MODE_OK;
>+
>        return MODE_CLOCK_RANGE;
> }
> 
>@@ -1944,6 +2017,13 @@ static int intel_c20pll_calc_state(struct intel_crtc_state *crtc_state,
>        const struct intel_c20pll_state * const *tables;
>        int i;
> 
>+  /* try computed C20 HDMI tables before using consolidated tables */
>+  if (intel_crtc_has_type(crtc_state, INTEL_OUTPUT_HDMI)) {
>+          if (intel_c20_compute_hdmi_tmds_pll(crtc_state->port_clock,
>+                                              &crtc_state->cx0pll_state.c20) == 0)
>+                  return 0;
>+  }
>+
>        tables = intel_c20_pll_tables_get(crtc_state, encoder);
>        if (!tables)
>                return -EINVAL;
>@@ -2093,13 +2173,10 @@ static u8 intel_c20_get_dp_rate(u32 clock)
> 
> static u8 intel_c20_get_hdmi_rate(u32 clock)
> {
>-  switch (clock) {
>-  case 25175:
>-  case 27000:
>-  case 74250:
>-  case 148500:
>-  case 594000:
>+  if ((clock >= 25175) && (clock <= 600000))
>                return 0;
>+
>+  switch (clock) {
>        case 166670: /* 3 Gbps */
>        case 333330: /* 6 Gbps */
>        case 666670: /* 12 Gbps */
>diff --git a/drivers/gpu/drm/i915/display/intel_cx0_phy_regs.h b/drivers/gpu/drm/i915/display/intel_cx0_phy_regs.h
>index ab9d1d983b88..cb5d1be2ba19 100644
>--- a/drivers/gpu/drm/i915/display/intel_cx0_phy_regs.h
>+++ b/drivers/gpu/drm/i915/display/intel_cx0_phy_regs.h
>@@ -218,4 +218,57 @@
> 
> #define RAWLANEAONX_DIG_TX_MPLLB_CAL_DONE_BANK(idx) (0x303D + (idx))
> 
>+/* C20 HDMI computed pll definitions */
>+#define REFCLK_38_4_MHZ           38400000
>+#define CLOCK_4999MHZ             4999999999
>+#define CLOCK_9999MHZ             9999999999
>+#define DATARATE_3000000000       3000000000
>+#define DATARATE_3500000000       3500000000
>+#define DATARATE_4000000000       4000000000
>+#define MPLL_FRACN_DEN            0xFFFF
>+
>+#define SSC_UP_SPREAD             REG_BIT16(9)
>+#define WORD_CLK_DIV              REG_BIT16(8)
>+
>+#define MPLL_TX_CLK_DIV(val)      REG_FIELD_PREP16(C20_MPLLB_TX_CLK_DIV_MASK, val)
>+#define MPLL_MULTIPLIER(val)      REG_FIELD_PREP16(C20_MULTIPLIER_MASK, val)
>+
>+#define MPLLB_ANA_FREQ_VCO_0      0
>+#define MPLLB_ANA_FREQ_VCO_1      1
>+#define MPLLB_ANA_FREQ_VCO_2      2
>+#define MPLLB_ANA_FREQ_VCO_3      3
>+#define MPLLB_ANA_FREQ_VCO_MASK   REG_GENMASK16(15, 14)
>+#define MPLLB_ANA_FREQ_VCO(val)   REG_FIELD_PREP16(MPLLB_ANA_FREQ_VCO_MASK, val)
>+
>+#define MPLL_DIV_MULTIPLIER_MASK  REG_GENMASK16(7, 0)
>+#define MPLL_DIV_MULTIPLIER(val)  REG_FIELD_PREP16(MPLL_DIV_MULTIPLIER_MASK, val)
>+
>+#define CAL_DAC_CODE_31           31
>+#define CAL_DAC_CODE_MASK REG_GENMASK16(14, 10)
>+#define CAL_DAC_CODE(val) REG_FIELD_PREP16(CAL_DAC_CODE_MASK, val)
>+
>+#define CP_INT_GS_28              28
>+#define CP_INT_GS_MASK            REG_GENMASK16(6, 0)
>+#define CP_INT_GS(val)            REG_FIELD_PREP16(CP_INT_GS_MASK, val)
>+
>+#define CP_PROP_GS_30             30
>+#define CP_PROP_GS_MASK           REG_GENMASK16(13, 7)
>+#define CP_PROP_GS(val)           REG_FIELD_PREP16(CP_PROP_GS_MASK, val)
>+
>+#define CP_INT_6          6
>+#define CP_INT_MASK               REG_GENMASK16(6, 0)
>+#define CP_INT(val)               REG_FIELD_PREP16(CP_INT_MASK, val)
>+
>+#define CP_PROP_20                20
>+#define CP_PROP_MASK              REG_GENMASK16(13, 7)
>+#define CP_PROP(val)              REG_FIELD_PREP16(CP_PROP_MASK, val)
>+
>+#define V2I_2                     2
>+#define V2I_MASK          REG_GENMASK16(15, 14)
>+#define V2I(val)          REG_FIELD_PREP16(V2I_MASK, val)
>+
>+#define HDMI_DIV_1                1
>+#define HDMI_DIV_MASK             REG_GENMASK16(2, 0)
>+#define HDMI_DIV(val)             REG_FIELD_PREP16(HDMI_DIV_MASK, val)
>+
> #endif /* __INTEL_CX0_REG_DEFS_H__ */
>-- 
>2.25.1
>


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