[Intel-gfx] [PATCH v2 46/50] drm/i915/dg2: Wait for SNPS PHY calibration during display init

[Matt Atwood]

On Tue, Jul 13, 2021 at 08:15:36PM -0700, Matt Roper wrote:
> Initialization of the PHY is handled by the hardware/firmware, but the
> driver should wait up to 25ms for the PHY to report that its calibration
> has completed.
> 
> Bspec: 49189
> Bspec: 50107
> Cc: Matt Atwood <matthew.s.atwood at intel.com>
> Signed-off-by: Matt Roper <matthew.d.roper at intel.com>
Reviewed-by: Matt Atwood <matthew.s.atwood at intel.com>
> ---
>  .../gpu/drm/i915/display/intel_display_power.c    |  5 +++++
>  drivers/gpu/drm/i915/display/intel_snps_phy.c     | 15 +++++++++++++++
>  drivers/gpu/drm/i915/display/intel_snps_phy.h     |  3 +++
>  drivers/gpu/drm/i915/i915_reg.h                   |  1 +
>  4 files changed, 24 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_display_power.c b/drivers/gpu/drm/i915/display/intel_display_power.c
> index 9593c517a321..2fb178a27327 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_power.c
> +++ b/drivers/gpu/drm/i915/display/intel_display_power.c
> @@ -18,6 +18,7 @@
>  #include "intel_pm.h"
>  #include "intel_pps.h"
>  #include "intel_sideband.h"
> +#include "intel_snps_phy.h"
>  #include "intel_tc.h"
>  #include "intel_vga.h"
>  
> @@ -5900,6 +5901,10 @@ static void icl_display_core_init(struct drm_i915_private *dev_priv,
>  	if (DISPLAY_VER(dev_priv) >= 12)
>  		tgl_bw_buddy_init(dev_priv);
>  
> +	/* 8. Ensure PHYs have completed calibration and adaptation */
> +	if (IS_DG2(dev_priv))
> +		intel_snps_phy_wait_for_calibration(dev_priv);
> +
>  	if (resume && intel_dmc_has_payload(dev_priv))
>  		intel_dmc_load_program(dev_priv);
>  
> diff --git a/drivers/gpu/drm/i915/display/intel_snps_phy.c b/drivers/gpu/drm/i915/display/intel_snps_phy.c
> index 77759bda98a4..f0c30d3d2dfb 100644
> --- a/drivers/gpu/drm/i915/display/intel_snps_phy.c
> +++ b/drivers/gpu/drm/i915/display/intel_snps_phy.c
> @@ -21,6 +21,21 @@
>   * since it is not handled by the shared DPLL framework as on other platforms.
>   */
>  
> +void intel_snps_phy_wait_for_calibration(struct drm_i915_private *dev_priv)
> +{
> +	enum phy phy;
> +
> +	for_each_phy_masked(phy, ~0) {
> +		if (!intel_phy_is_snps(dev_priv, phy))
> +			continue;
> +
> +		if (intel_de_wait_for_clear(dev_priv, ICL_PHY_MISC(phy),
> +					    DG2_PHY_DP_TX_ACK_MASK, 25))
> +			DRM_ERROR("SNPS PHY %c failed to calibrate after 25ms.\n",
> +				  phy);
> +	}
> +}
> +
>  static const u32 dg2_ddi_translations[] = {
>  	/* VS 0, pre-emph 0 */
>  	REG_FIELD_PREP(SNPS_PHY_TX_EQ_MAIN, 26),
> diff --git a/drivers/gpu/drm/i915/display/intel_snps_phy.h b/drivers/gpu/drm/i915/display/intel_snps_phy.h
> index 3ce92d424f66..6aa33ff729ec 100644
> --- a/drivers/gpu/drm/i915/display/intel_snps_phy.h
> +++ b/drivers/gpu/drm/i915/display/intel_snps_phy.h
> @@ -8,10 +8,13 @@
>  
>  #include <linux/types.h>
>  
> +struct drm_i915_private;
>  struct intel_encoder;
>  struct intel_crtc_state;
>  struct intel_mpllb_state;
>  
> +void intel_snps_phy_wait_for_calibration(struct drm_i915_private *dev_priv);
> +
>  int intel_mpllb_calc_state(struct intel_crtc_state *crtc_state,
>  			   struct intel_encoder *encoder);
>  void intel_mpllb_enable(struct intel_encoder *encoder,
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index c44031dcdcb4..9c7dc812317e 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -12454,6 +12454,7 @@ enum skl_power_gate {
>  						 _ICL_PHY_MISC_B)
>  #define  ICL_PHY_MISC_MUX_DDID			(1 << 28)
>  #define  ICL_PHY_MISC_DE_IO_COMP_PWR_DOWN	(1 << 23)
> +#define  DG2_PHY_DP_TX_ACK_MASK			REG_GENMASK(23, 20)
>  
>  /* Icelake Display Stream Compression Registers */
>  #define DSCA_PICTURE_PARAMETER_SET_0		_MMIO(0x6B200)
> -- 
> 2.25.4
>