[Intel-gfx] [PATCH v2 43/50] drm/i915/dg2: Add vswing programming for SNPS phys

Matt Atwood matthew.s.atwood at intel.com
Fri Jul 16 21:38:56 UTC 2021


On Tue, Jul 13, 2021 at 08:15:33PM -0700, Matt Roper wrote:
> Vswing programming for SNPS PHYs is just a single step -- look up the
> value that corresponds to the voltage level from a table and program it
> into the SNPS_PHY_TX_EQ register.
> 
> Bspec: 53920
> Cc: Matt Atwood <matthew.s.atwood at intel.com>
> Signed-off-by: Matt Roper <matthew.d.roper at intel.com>
> Signed-off-by: Jani Nikula <jani.nikula at intel.com>
Reviewed-by: Matt Atwood <matthew.s.atwood at intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_ddi.c      | 23 ++++++--
>  drivers/gpu/drm/i915/display/intel_snps_phy.c | 54 +++++++++++++++++++
>  drivers/gpu/drm/i915/display/intel_snps_phy.h |  4 ++
>  drivers/gpu/drm/i915/i915_reg.h               |  5 ++
>  4 files changed, 83 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
> index 929a95ddb316..ade03cf41caa 100644
> --- a/drivers/gpu/drm/i915/display/intel_ddi.c
> +++ b/drivers/gpu/drm/i915/display/intel_ddi.c
> @@ -1496,6 +1496,16 @@ static int intel_ddi_dp_level(struct intel_dp *intel_dp)
>  	return translate_signal_level(intel_dp, signal_levels);
>  }
>  
> +static void
> +dg2_set_signal_levels(struct intel_dp *intel_dp,
> +		      const struct intel_crtc_state *crtc_state)
> +{
> +	struct intel_encoder *encoder = &dp_to_dig_port(intel_dp)->base;
> +	int level = intel_ddi_dp_level(intel_dp);
> +
> +	intel_snps_phy_ddi_vswing_sequence(encoder, level);
> +}
> +
>  static void
>  tgl_set_signal_levels(struct intel_dp *intel_dp,
>  		      const struct intel_crtc_state *crtc_state)
> @@ -2563,7 +2573,10 @@ static void tgl_ddi_pre_enable_dp(struct intel_atomic_state *state,
>  	 */
>  
>  	/* 7.e Configure voltage swing and related IO settings */
> -	tgl_ddi_vswing_sequence(encoder, crtc_state, level);
> +	if (IS_DG2(dev_priv))
> +		intel_snps_phy_ddi_vswing_sequence(encoder, level);
> +	else
> +		tgl_ddi_vswing_sequence(encoder, crtc_state, level);
>  
>  	/*
>  	 * 7.f Combo PHY: Configure PORT_CL_DW10 Static Power Down to power up
> @@ -3102,7 +3115,9 @@ static void intel_enable_ddi_hdmi(struct intel_atomic_state *state,
>  			    "[CONNECTOR:%d:%s] Failed to configure sink scrambling/TMDS bit clock ratio\n",
>  			    connector->base.id, connector->name);
>  
> -	if (DISPLAY_VER(dev_priv) >= 12)
> +	if (IS_DG2(dev_priv))
> +		intel_snps_phy_ddi_vswing_sequence(encoder, U32_MAX);
> +	else if (DISPLAY_VER(dev_priv) >= 12)
>  		tgl_ddi_vswing_sequence(encoder, crtc_state, level);
>  	else if (DISPLAY_VER(dev_priv) == 11)
>  		icl_ddi_vswing_sequence(encoder, crtc_state, level);
> @@ -4075,7 +4090,9 @@ intel_ddi_init_dp_connector(struct intel_digital_port *dig_port)
>  	dig_port->dp.set_link_train = intel_ddi_set_link_train;
>  	dig_port->dp.set_idle_link_train = intel_ddi_set_idle_link_train;
>  
> -	if (DISPLAY_VER(dev_priv) >= 12)
> +	if (IS_DG2(dev_priv))
> +		dig_port->dp.set_signal_levels = dg2_set_signal_levels;
> +	else if (DISPLAY_VER(dev_priv) >= 12)
>  		dig_port->dp.set_signal_levels = tgl_set_signal_levels;
>  	else if (DISPLAY_VER(dev_priv) >= 11)
>  		dig_port->dp.set_signal_levels = icl_set_signal_levels;
> diff --git a/drivers/gpu/drm/i915/display/intel_snps_phy.c b/drivers/gpu/drm/i915/display/intel_snps_phy.c
> index 1317b4e94b50..77759bda98a4 100644
> --- a/drivers/gpu/drm/i915/display/intel_snps_phy.c
> +++ b/drivers/gpu/drm/i915/display/intel_snps_phy.c
> @@ -21,6 +21,60 @@
>   * since it is not handled by the shared DPLL framework as on other platforms.
>   */
>  
> +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)
> +{
> +	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
> +	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)
> +		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]);
> +}
> +
>  /*
>   * Basic DP link rates with 100 MHz reference clock.
>   */
> diff --git a/drivers/gpu/drm/i915/display/intel_snps_phy.h b/drivers/gpu/drm/i915/display/intel_snps_phy.h
> index ca4c2a25182b..3ce92d424f66 100644
> --- a/drivers/gpu/drm/i915/display/intel_snps_phy.h
> +++ b/drivers/gpu/drm/i915/display/intel_snps_phy.h
> @@ -6,6 +6,8 @@
>  #ifndef __INTEL_SNPS_PHY_H__
>  #define __INTEL_SNPS_PHY_H__
>  
> +#include <linux/types.h>
> +
>  struct intel_encoder;
>  struct intel_crtc_state;
>  struct intel_mpllb_state;
> @@ -21,5 +23,7 @@ int intel_mpllb_calc_port_clock(struct intel_encoder *encoder,
>  				const struct intel_mpllb_state *pll_state);
>  
>  int intel_snps_phy_check_hdmi_link_rate(int clock);
> +void intel_snps_phy_ddi_vswing_sequence(struct intel_encoder *encoder,
> +					u32 level);
>  
>  #endif /* __INTEL_SNPS_PHY_H__ */
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index 92408b4e2730..c44031dcdcb4 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -2340,6 +2340,11 @@ static inline bool i915_mmio_reg_valid(i915_reg_t reg)
>  #define SNPS_PHY_REF_CONTROL(phy)		_MMIO_SNPS(phy, 0x168188)
>  #define   SNPS_PHY_REF_CONTROL_REF_RANGE	REG_GENMASK(31, 27)
>  
> +#define SNPS_PHY_TX_EQ(ln, phy)			_MMIO_SNPS_LN(ln, phy, 0x168300)
> +#define   SNPS_PHY_TX_EQ_MAIN			REG_GENMASK(23, 18)
> +#define   SNPS_PHY_TX_EQ_POST			REG_GENMASK(15, 10)
> +#define   SNPS_PHY_TX_EQ_PRE			REG_GENMASK(7, 2)
> +
>  /* The spec defines this only for BXT PHY0, but lets assume that this
>   * would exist for PHY1 too if it had a second channel.
>   */
> -- 
> 2.25.4
> 


More information about the Intel-gfx mailing list