[PATCH] drm/i915/xe2lpd: Update C20 HDMI TMDS algorithm to include tx_misc

[Gustavo Sousa]

Quoting Pottumuttu, Sai Teja (2024-10-18 11:16:43-03:00)
>
>On 18-10-2024 02:23, Gustavo Sousa wrote:
>> There has been an update to the Bspec in which we need to set
>> tx_misc=0x5 field for C20 TX Context programming for HDMI TMDS for
>> Xe2_LPD and newer. That field is mapped to the bits 7:0 of
>> SRAM_GENERIC_<A/B>_TX_CNTX_CFG_1, which in turn translates to tx[1] of
>> our state struct. Update the algorithm to reflect this change.
>>
>> Bspec: 74489
>Nit: Would 74491 be a better Bspec here?

Oops. You're right. I remember having that one open as well while
implementing this, so I ended up copying the wrong reference. Thanks!

>> Signed-off-by: Gustavo Sousa <gustavo.sousa at intel.com>
>> ---
>>   drivers/gpu/drm/i915/display/intel_cx0_phy.c    | 17 ++++++++++++++---
>>   .../gpu/drm/i915/display/intel_cx0_phy_regs.h   |  2 ++
>>   2 files changed, 16 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/display/intel_cx0_phy.c b/drivers/gpu/drm/i915/display/intel_cx0_phy.c
>> index f73d576fd99e..22184b2d5a11 100644
>> --- a/drivers/gpu/drm/i915/display/intel_cx0_phy.c
>> +++ b/drivers/gpu/drm/i915/display/intel_cx0_phy.c
>> @@ -2142,8 +2142,12 @@ static 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)
>> +static int intel_c20_compute_hdmi_tmds_pll(struct intel_encoder *encoder,
>> +                                           u64 pixel_clock,
>> +                                           struct intel_c20pll_state *pll_state)
>>   {
>> +        struct drm_i915_private *i915 = to_i915(encoder->base.dev);
>> +
>>           u64 datarate;
>>           u64 mpll_tx_clk_div;
>>           u64 vco_freq_shift;
>> @@ -2154,6 +2158,7 @@ static int intel_c20_compute_hdmi_tmds_pll(u64 pixel_clock, struct intel_c20pll_
>>           u64 mpll_fracn_rem;
>>           u8  mpllb_ana_freq_vco;
>>           u8  mpll_div_multiplier;
>> +        u16  tx_misc;
>>   
>>           if (pixel_clock < 25175 || pixel_clock > 600000)
>>                   return -EINVAL;
>> @@ -2171,6 +2176,11 @@ static int intel_c20_compute_hdmi_tmds_pll(u64 pixel_clock, struct intel_c20pll_
>>           mpll_div_multiplier = min_t(u8, div64_u64((vco_freq * 16 + (datarate >> 1)),
>>                                                     datarate), 255);
>>   
>> +        if (DISPLAY_VER(i915) >= 20)
>> +                tx_misc = 0x5;
>> +        else
>> +                tx_misc = 0x0;
>Looks like tx_misc changed from 0x1 to 0x5 and not from 0x0.

Yeah and it looks like we missed doing that update. However, I'm not
sure what you mean here. Do you mean to use 0x1 for the "else" case? If
so, then I think we should not do it. The change was from 0x1 to 0x5 for
Xe2_LPD and newer displays.

--
Gustavo Sousa

>
>Thanks
>Sai Teja
>> +
>>           if (vco_freq <= DATARATE_3000000000)
>>                   mpllb_ana_freq_vco = MPLLB_ANA_FREQ_VCO_3;
>>           else if (vco_freq <= DATARATE_3500000000)
>> @@ -2182,7 +2192,7 @@ static int intel_c20_compute_hdmi_tmds_pll(u64 pixel_clock, struct intel_c20pll_
>>   
>>           pll_state->clock        = pixel_clock;
>>           pll_state->tx[0]        = 0xbe88;
>> -        pll_state->tx[1]        = 0x9800;
>> +        pll_state->tx[1]        = 0x9800 | C20_PHY_TX_MISC(tx_misc);
>>           pll_state->tx[2]        = 0x0000;
>>           pll_state->cmn[0]        = 0x0500;
>>           pll_state->cmn[1]        = 0x0005;
>> @@ -2266,7 +2276,8 @@ static int intel_c20pll_calc_state(struct intel_crtc_state *crtc_state,
>>   
>>           /* 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,
>> +                if (intel_c20_compute_hdmi_tmds_pll(encoder,
>> +                                                    crtc_state->port_clock,
>>                                                       &crtc_state->dpll_hw_state.cx0pll.c20) == 0)
>>                           return 0;
>>           }
>> 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 ab3ae110b68f..c1949aa1b909 100644
>> --- a/drivers/gpu/drm/i915/display/intel_cx0_phy_regs.h
>> +++ b/drivers/gpu/drm/i915/display/intel_cx0_phy_regs.h
>> @@ -280,6 +280,8 @@
>>   #define PHY_C20_B_TX_CNTX_CFG(i915, idx) \
>>                   ((_IS_XE2HPD_C20(i915) ? _XE2HPD_C20_B_TX_CNTX_CFG : _MTL_C20_B_TX_CNTX_CFG) - (idx))
>>   #define   C20_PHY_TX_RATE                REG_GENMASK(2, 0)
>> +#define   C20_PHY_TX_MISC_MASK                REG_GENMASK(7, 0)
>> +#define   C20_PHY_TX_MISC(val)                REG_FIELD_PREP16(C20_PHY_TX_MISC_MASK, (val))
>>   
>>   #define PHY_C20_A_CMN_CNTX_CFG(i915, idx) \
>>                   ((_IS_XE2HPD_C20(i915) ? _XE2HPD_C20_A_CMN_CNTX_CFG : _MTL_C20_A_CMN_CNTX_CFG) - (idx))