Re: [Intel-gfx] [PATCH 2/3] drm/i915/dg2: use existing mechanisms for SNPS PHY translations

[Matt Roper <matthew.d.roper@intel.com>]

On Fri, Aug 13, 2021 at 10:54:25PM +0300, Jani Nikula wrote:
> On Fri, 13 Aug 2021, Jani Nikula <jani.nikula@intel.com> wrote:
> > On Fri, 13 Aug 2021, Matt Roper <matthew.d.roper@intel.com> wrote:
> >> On Fri, Aug 13, 2021 at 02:51:50PM +0300, Jani Nikula wrote:
> >>> We use encoder->get_buf_trans() in many places, for example
> >>> intel_ddi_dp_voltage_max(), and the hook was set to some old platform's
> >>> function for DG2 SNPS PHY. Convert SNPS PHY to use the same translation
> >>> mechanisms as everything else.
> >>> 
> >>> Cc: Manasi Navare <manasi.d.navare@intel.com>
> >>> Cc: Matt Roper <matthew.d.roper@intel.com>
> >>> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
> >>> ---
> >>>  drivers/gpu/drm/i915/display/intel_ddi.c      |  6 +-
> >>>  .../drm/i915/display/intel_ddi_buf_trans.c    | 31 +++++++++-
> >>>  .../drm/i915/display/intel_ddi_buf_trans.h    |  7 +++
> >>>  drivers/gpu/drm/i915/display/intel_snps_phy.c | 61 ++++++-------------
> >>>  drivers/gpu/drm/i915/display/intel_snps_phy.h |  3 +-
> >>>  5 files changed, 59 insertions(+), 49 deletions(-)
> >>> 
> >>> diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
> >>> index 8cf5d1572ee0..9e46cf5c4378 100644
> >>> --- a/drivers/gpu/drm/i915/display/intel_ddi.c
> >>> +++ b/drivers/gpu/drm/i915/display/intel_ddi.c
> >>> @@ -1388,7 +1388,7 @@ dg2_set_signal_levels(struct intel_dp *intel_dp,
> >>>  	struct intel_encoder *encoder = &dp_to_dig_port(intel_dp)->base;
> >>>  	int level = intel_ddi_dp_level(intel_dp, crtc_state);
> >>>  
> >>> -	intel_snps_phy_ddi_vswing_sequence(encoder, level);
> >>> +	intel_snps_phy_ddi_vswing_sequence(encoder, crtc_state, level);
> >>>  }
> >>>  
> >>>  static void
> >>> @@ -2388,7 +2388,7 @@ static void dg2_ddi_pre_enable_dp(struct intel_atomic_state *state,
> >>>  	 */
> >>>  
> >>>  	/* 5.e Configure voltage swing and related IO settings */
> >>> -	intel_snps_phy_ddi_vswing_sequence(encoder, level);
> >>> +	intel_snps_phy_ddi_vswing_sequence(encoder, crtc_state, level);
> >>>  
> >>>  	/*
> >>>  	 * 5.f Configure and enable DDI_BUF_CTL
> >>> @@ -3057,7 +3057,7 @@ static void intel_enable_ddi_hdmi(struct intel_atomic_state *state,
> >>>  			    connector->base.id, connector->name);
> >>>  
> >>>  	if (IS_DG2(dev_priv))
> >>> -		intel_snps_phy_ddi_vswing_sequence(encoder, U32_MAX);
> >>> +		intel_snps_phy_ddi_vswing_sequence(encoder, crtc_state, level);
> >>>  	else if (DISPLAY_VER(dev_priv) >= 12)
> >>>  		tgl_ddi_vswing_sequence(encoder, crtc_state, level);
> >>>  	else if (DISPLAY_VER(dev_priv) == 11)
> >>> diff --git a/drivers/gpu/drm/i915/display/intel_ddi_buf_trans.c b/drivers/gpu/drm/i915/display/intel_ddi_buf_trans.c
> >>> index ba2c08f1a797..ebb39624bfc9 100644
> >>> --- a/drivers/gpu/drm/i915/display/intel_ddi_buf_trans.c
> >>> +++ b/drivers/gpu/drm/i915/display/intel_ddi_buf_trans.c
> >>> @@ -983,6 +983,25 @@ static const struct intel_ddi_buf_trans adlp_dkl_phy_ddi_translations_dp_hbr2_hb
> >>>  	.num_entries = ARRAY_SIZE(_adlp_dkl_phy_ddi_translations_dp_hbr2_hbr3),
> >>>  };
> >>>  
> >>> +static const union intel_ddi_buf_trans_entry _dg2_snps_translations[] = {
> >>> +	{ .snps = { 26, 0, 0 } },	/* VS 0, pre-emph 0 */
> >>> +	{ .snps = { 33, 0, 6 } },	/* VS 0, pre-emph 1 */
> >>> +	{ .snps = { 38, 0, 12 } },	/* VS 0, pre-emph 2 */
> >>> +	{ .snps = { 43, 0, 19 } },	/* VS 0, pre-emph 3 */
> >>> +	{ .snps = { 39, 0, 0 } },	/* VS 1, pre-emph 0 */
> >>> +	{ .snps = { 44, 0, 8 } },	/* VS 1, pre-emph 1 */
> >>> +	{ .snps = { 47, 0, 15 } },	/* VS 1, pre-emph 2 */
> >>> +	{ .snps = { 52, 0, 0 } },	/* VS 2, pre-emph 0 */
> >>> +	{ .snps = { 51, 0, 10 } },	/* VS 2, pre-emph 1 */
> >>> +	{ .snps = { 62, 0, 0 } },	/* VS 3, pre-emph 0 */
> >>> +};
> >>> +
> >>> +static const struct intel_ddi_buf_trans dg2_snps_translations = {
> >>> +	.entries = _dg2_snps_translations,
> >>> +	.num_entries = ARRAY_SIZE(_dg2_snps_translations),
> >>> +	.hdmi_default_entry = ARRAY_SIZE(_dg2_snps_translations) - 1,
> >>> +};
> >>> +
> >>>  bool is_hobl_buf_trans(const struct intel_ddi_buf_trans *table)
> >>>  {
> >>>  	return table == &tgl_combo_phy_ddi_translations_edp_hbr2_hobl;
> >>> @@ -1563,6 +1582,14 @@ adlp_get_dkl_buf_trans(struct intel_encoder *encoder,
> >>>  		return adlp_get_dkl_buf_trans_dp(encoder, crtc_state, n_entries);
> >>>  }
> >>>  
> >>> +static const struct intel_ddi_buf_trans *
> >>> +dg2_get_snps_buf_trans(struct intel_encoder *encoder,
> >>> +		       const struct intel_crtc_state *crtc_state,
> >>> +		       int *n_entries)
> >>> +{
> >>> +	return intel_get_buf_trans(&dg2_snps_translations, n_entries);
> >>> +}
> >>> +
> >>>  int intel_ddi_hdmi_num_entries(struct intel_encoder *encoder,
> >>>  			       const struct intel_crtc_state *crtc_state,
> >>>  			       int *default_entry)
> >>> @@ -1588,7 +1615,9 @@ void intel_ddi_buf_trans_init(struct intel_encoder *encoder)
> >>>  	struct drm_i915_private *i915 = to_i915(encoder->base.dev);
> >>>  	enum phy phy = intel_port_to_phy(i915, encoder->port);
> >>>  
> >>> -	if (IS_ALDERLAKE_P(i915)) {
> >>> +	if (IS_DG2(i915)) {
> >>> +		encoder->get_buf_trans = dg2_get_snps_buf_trans;
> >>> +	} else if (IS_ALDERLAKE_P(i915)) {
> >>>  		if (intel_phy_is_combo(i915, phy))
> >>>  			encoder->get_buf_trans = adlp_get_combo_buf_trans;
> >>>  		else
> >>
> >> While we're at it, maybe change the 'else' to a IS_HASWELL check and
> >> then add a new 'else' with MISSING_CASE to make sure we don't miss this
> >> for future platforms?
> >>
> >> Up to you.  Either way,
> >>
> >> Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
> >
> > Thanks! I decided to push these as-is, and will send a follow-up to add
> > the MISSING_CASE.
> 
> I wrote the patch, but realized the DISPLAY_VER(i915) >= 12 case will
> catch most new platforms anyway. Do you still think it's worth it?

Doesn't matter too much to me either way.  We could change that ">=" to
"==" so that that case stops catching anything that should be version 13
or beyond.  Up to you though.


Matt

> 
> BR,
> Jani.
> 
> 
> >
> > BR,
> > Jani.
> >
> >
> >>
> >>
> >>> diff --git a/drivers/gpu/drm/i915/display/intel_ddi_buf_trans.h b/drivers/gpu/drm/i915/display/intel_ddi_buf_trans.h
> >>> index 2acd720f9d4f..94d338287f61 100644
> >>> --- a/drivers/gpu/drm/i915/display/intel_ddi_buf_trans.h
> >>> +++ b/drivers/gpu/drm/i915/display/intel_ddi_buf_trans.h
> >>> @@ -45,12 +45,19 @@ struct tgl_dkl_phy_ddi_buf_trans {
> >>>  	u32 dkl_de_emphasis_control;
> >>>  };
> >>>  
> >>> +struct dg2_snps_phy_buf_trans {
> >>> +	u8 snps_vswing;
> >>> +	u8 snps_pre_cursor;
> >>> +	u8 snps_post_cursor;
> >>> +};
> >>> +
> >>>  union intel_ddi_buf_trans_entry {
> >>>  	struct hsw_ddi_buf_trans hsw;
> >>>  	struct bxt_ddi_buf_trans bxt;
> >>>  	struct icl_ddi_buf_trans icl;
> >>>  	struct icl_mg_phy_ddi_buf_trans mg;
> >>>  	struct tgl_dkl_phy_ddi_buf_trans dkl;
> >>> +	struct dg2_snps_phy_buf_trans snps;
> >>>  };
> >>>  
> >>>  struct intel_ddi_buf_trans {
> >>> diff --git a/drivers/gpu/drm/i915/display/intel_snps_phy.c b/drivers/gpu/drm/i915/display/intel_snps_phy.c
> >>> index 18b52b64af95..d81f71296297 100644
> >>> --- a/drivers/gpu/drm/i915/display/intel_snps_phy.c
> >>> +++ b/drivers/gpu/drm/i915/display/intel_snps_phy.c
> >>> @@ -5,6 +5,7 @@
> >>>  
> >>>  #include <linux/util_macros.h>
> >>>  
> >>> +#include "intel_ddi_buf_trans.h"
> >>>  #include "intel_de.h"
> >>>  #include "intel_display_types.h"
> >>>  #include "intel_snps_phy.h"
> >>> @@ -50,58 +51,30 @@ void intel_snps_phy_update_psr_power_state(struct drm_i915_private *dev_priv,
> >>>  			 SNPS_PHY_TX_REQ_LN_DIS_PWR_STATE_PSR, val);
> >>>  }
> >>>  
> >>> -static const u32 dg2_ddi_translations[] = {
> >>> -	/* VS 0, pre-emph 0 */
> >>> -	REG_FIELD_PREP(SNPS_PHY_TX_EQ_MAIN, 26),
> >>> -
> >>> -	/* VS 0, pre-emph 1 */
> >>> -	REG_FIELD_PREP(SNPS_PHY_TX_EQ_MAIN, 33) |
> >>> -		REG_FIELD_PREP(SNPS_PHY_TX_EQ_POST, 6),
> >>> -
> >>> -	/* VS 0, pre-emph 2 */
> >>> -	REG_FIELD_PREP(SNPS_PHY_TX_EQ_MAIN, 38) |
> >>> -		REG_FIELD_PREP(SNPS_PHY_TX_EQ_POST, 12),
> >>> -
> >>> -	/* VS 0, pre-emph 3 */
> >>> -	REG_FIELD_PREP(SNPS_PHY_TX_EQ_MAIN, 43) |
> >>> -		REG_FIELD_PREP(SNPS_PHY_TX_EQ_POST, 19),
> >>> -
> >>> -	/* VS 1, pre-emph 0 */
> >>> -	REG_FIELD_PREP(SNPS_PHY_TX_EQ_MAIN, 39),
> >>> -
> >>> -	/* VS 1, pre-emph 1 */
> >>> -	REG_FIELD_PREP(SNPS_PHY_TX_EQ_MAIN, 44) |
> >>> -		REG_FIELD_PREP(SNPS_PHY_TX_EQ_POST, 8),
> >>> -
> >>> -	/* VS 1, pre-emph 2 */
> >>> -	REG_FIELD_PREP(SNPS_PHY_TX_EQ_MAIN, 47) |
> >>> -		REG_FIELD_PREP(SNPS_PHY_TX_EQ_POST, 15),
> >>> -
> >>> -	/* VS 2, pre-emph 0 */
> >>> -	REG_FIELD_PREP(SNPS_PHY_TX_EQ_MAIN, 52),
> >>> -
> >>> -	/* VS 2, pre-emph 1 */
> >>> -	REG_FIELD_PREP(SNPS_PHY_TX_EQ_MAIN, 51) |
> >>> -		REG_FIELD_PREP(SNPS_PHY_TX_EQ_POST, 10),
> >>> -
> >>> -	/* VS 3, pre-emph 0 */
> >>> -	REG_FIELD_PREP(SNPS_PHY_TX_EQ_MAIN, 62),
> >>> -};
> >>> -
> >>>  void intel_snps_phy_ddi_vswing_sequence(struct intel_encoder *encoder,
> >>> -					u32 level)
> >>> +					const struct intel_crtc_state *crtc_state,
> >>> +					int level)
> >>>  {
> >>>  	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
> >>> +	const struct intel_ddi_buf_trans *ddi_translations;
> >>>  	enum phy phy = intel_port_to_phy(dev_priv, encoder->port);
> >>>  	int n_entries, ln;
> >>>  
> >>> -	n_entries = ARRAY_SIZE(dg2_ddi_translations);
> >>> -	if (level >= n_entries)
> >>> +	ddi_translations = encoder->get_buf_trans(encoder, crtc_state, &n_entries);
> >>> +	if (drm_WARN_ON_ONCE(&dev_priv->drm, !ddi_translations))
> >>> +		return;
> >>> +	if (drm_WARN_ON_ONCE(&dev_priv->drm, level < 0 || level >= n_entries))
> >>>  		level = n_entries - 1;
> >>>  
> >>> -	for (ln = 0; ln < 4; ln++)
> >>> -		intel_de_write(dev_priv, SNPS_PHY_TX_EQ(ln, phy),
> >>> -			       dg2_ddi_translations[level]);
> >>> +	for (ln = 0; ln < 4; ln++) {
> >>> +		u32 val = 0;
> >>> +
> >>> +		val |= REG_FIELD_PREP(SNPS_PHY_TX_EQ_MAIN, ddi_translations->entries[level].snps.snps_vswing);
> >>> +		val |= REG_FIELD_PREP(SNPS_PHY_TX_EQ_PRE, ddi_translations->entries[level].snps.snps_pre_cursor);
> >>> +		val |= REG_FIELD_PREP(SNPS_PHY_TX_EQ_POST, ddi_translations->entries[level].snps.snps_post_cursor);
> >>> +
> >>> +		intel_de_write(dev_priv, SNPS_PHY_TX_EQ(ln, phy), val);
> >>> +	}
> >>>  }
> >>>  
> >>>  /*
> >>> diff --git a/drivers/gpu/drm/i915/display/intel_snps_phy.h b/drivers/gpu/drm/i915/display/intel_snps_phy.h
> >>> index 6261ff88ef5c..a68547a6fee5 100644
> >>> --- a/drivers/gpu/drm/i915/display/intel_snps_phy.h
> >>> +++ b/drivers/gpu/drm/i915/display/intel_snps_phy.h
> >>> @@ -30,6 +30,7 @@ int intel_mpllb_calc_port_clock(struct intel_encoder *encoder,
> >>>  
> >>>  int intel_snps_phy_check_hdmi_link_rate(int clock);
> >>>  void intel_snps_phy_ddi_vswing_sequence(struct intel_encoder *encoder,
> >>> -					u32 level);
> >>> +					const struct intel_crtc_state *crtc_state,
> >>> +					int level);
> >>>  
> >>>  #endif /* __INTEL_SNPS_PHY_H__ */
> >>> -- 
> >>> 2.20.1
> >>> 
> 
> -- 
> Jani Nikula, Intel Open Source Graphics Center

-- 
Matt Roper
Graphics Software Engineer
VTT-OSGC Platform Enablement
Intel Corporation
(916) 356-2795