[PATCH 1/2] drm/i915/xe2lpd: Move D2D enable/disable

[Matt Roper]

On Fri, Jan 26, 2024 at 02:46:36PM -0800, Lucas De Marchi wrote:
> Bits to enable/disable and check state for D2D moved from
> XELPDP_PORT_BUF_CTL1 to DDI_BUF_CTL (now named DDI_CTL_DE in the spec).
> Make the functions mtl_ddi_disable_d2d() and mtl_ddi_enable_d2d generic
> to work with multiple reg location and bitfield layout.
> 
> v2: Set/Clear XE2LPD_DDI_BUF_D2D_LINK_ENABLE in saved_port_bits when
>     enabling/disabling D2D so DDI_BUF_CTL is correctly programmed in
>     other places without overriding these bits (Clint)
> v3: Leave saved_port_bits alone as those bits are not meant to be
>     modified outside of the port initialization. Rather propagate the
>     additional bit in DDI_BUF_CTL to be set when that register is
>     written again after D2D is enabled.
> 
> Cc: Matt Roper <matthew.d.roper at intel.com>
> Signed-off-by: Lucas De Marchi <lucas.demarchi at intel.com>

Reviewed-by: Matt Roper <matthew.d.roper at intel.com>

> ---
>  drivers/gpu/drm/i915/display/intel_ddi.c | 44 ++++++++++++++++++------
>  drivers/gpu/drm/i915/i915_reg.h          |  2 ++
>  2 files changed, 36 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
> index 12a29363e5df..188c537dbb5d 100644
> --- a/drivers/gpu/drm/i915/display/intel_ddi.c
> +++ b/drivers/gpu/drm/i915/display/intel_ddi.c
> @@ -2429,13 +2429,22 @@ mtl_ddi_enable_d2d(struct intel_encoder *encoder)
>  {
>  	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
>  	enum port port = encoder->port;
> +	i915_reg_t reg;
> +	u32 set_bits, wait_bits;
>  
> -	intel_de_rmw(dev_priv, XELPDP_PORT_BUF_CTL1(port), 0,
> -		     XELPDP_PORT_BUF_D2D_LINK_ENABLE);
> +	if (DISPLAY_VER(dev_priv) >= 20) {
> +		reg = DDI_BUF_CTL(port);
> +		set_bits = XE2LPD_DDI_BUF_D2D_LINK_ENABLE;
> +		wait_bits = XE2LPD_DDI_BUF_D2D_LINK_STATE;
> +	} else {
> +		reg = XELPDP_PORT_BUF_CTL1(port);
> +		set_bits = XELPDP_PORT_BUF_D2D_LINK_ENABLE;
> +		wait_bits = XELPDP_PORT_BUF_D2D_LINK_STATE;
> +	}
>  
> -	if (wait_for_us((intel_de_read(dev_priv, XELPDP_PORT_BUF_CTL1(port)) &
> -			 XELPDP_PORT_BUF_D2D_LINK_STATE), 100)) {
> -		drm_err(&dev_priv->drm, "Timeout waiting for D2D Link enable for PORT_BUF_CTL %c\n",
> +	intel_de_rmw(dev_priv, reg, 0, set_bits);
> +	if (wait_for_us(intel_de_read(dev_priv, reg) & wait_bits, 100)) {
> +		drm_err(&dev_priv->drm, "Timeout waiting for D2D Link enable for DDI/PORT_BUF_CTL %c\n",
>  			port_name(port));
>  	}
>  }
> @@ -2898,13 +2907,22 @@ mtl_ddi_disable_d2d_link(struct intel_encoder *encoder)
>  {
>  	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
>  	enum port port = encoder->port;
> +	i915_reg_t reg;
> +	u32 clr_bits, wait_bits;
>  
> -	intel_de_rmw(dev_priv, XELPDP_PORT_BUF_CTL1(port),
> -		     XELPDP_PORT_BUF_D2D_LINK_ENABLE, 0);
> +	if (DISPLAY_VER(dev_priv) >= 20) {
> +		reg = DDI_BUF_CTL(port);
> +		clr_bits = XE2LPD_DDI_BUF_D2D_LINK_ENABLE;
> +		wait_bits = XE2LPD_DDI_BUF_D2D_LINK_STATE;
> +	} else {
> +		reg = XELPDP_PORT_BUF_CTL1(port);
> +		clr_bits = XELPDP_PORT_BUF_D2D_LINK_ENABLE;
> +		wait_bits = XELPDP_PORT_BUF_D2D_LINK_STATE;
> +	}
>  
> -	if (wait_for_us(!(intel_de_read(dev_priv, XELPDP_PORT_BUF_CTL1(port)) &
> -			  XELPDP_PORT_BUF_D2D_LINK_STATE), 100))
> -		drm_err(&dev_priv->drm, "Timeout waiting for D2D Link disable for PORT_BUF_CTL %c\n",
> +	intel_de_rmw(dev_priv, reg, clr_bits, 0);
> +	if (wait_for_us(!(intel_de_read(dev_priv, reg) & wait_bits), 100))
> +		drm_err(&dev_priv->drm, "Timeout waiting for D2D Link disable for DDI/PORT_BUF_CTL %c\n",
>  			port_name(port));
>  }
>  
> @@ -3323,6 +3341,9 @@ static void intel_enable_ddi_hdmi(struct intel_atomic_state *state,
>  			     XELPDP_PORT_WIDTH_MASK | XELPDP_PORT_REVERSAL, port_buf);
>  
>  		buf_ctl |= DDI_PORT_WIDTH(lane_count);
> +
> +		if (DISPLAY_VER(dev_priv) >= 20)
> +		       buf_ctl |= XE2LPD_DDI_BUF_D2D_LINK_ENABLE;
>  	} else if (IS_ALDERLAKE_P(dev_priv) && intel_phy_is_tc(dev_priv, phy)) {
>  		drm_WARN_ON(&dev_priv->drm, !intel_tc_port_in_legacy_mode(dig_port));
>  		buf_ctl |= DDI_BUF_CTL_TC_PHY_OWNERSHIP;
> @@ -3543,6 +3564,9 @@ static void mtl_ddi_prepare_link_retrain(struct intel_dp *intel_dp,
>  
>  	/* 6.i Configure and enable DDI_CTL_DE to start sending valid data to port slice */
>  	intel_dp->DP |= DDI_BUF_CTL_ENABLE;
> +	if (DISPLAY_VER(dev_priv) >= 20)
> +		intel_dp->DP |= XE2LPD_DDI_BUF_D2D_LINK_ENABLE;
> +
>  	intel_de_write(dev_priv, DDI_BUF_CTL(port), intel_dp->DP);
>  	intel_de_posting_read(dev_priv, DDI_BUF_CTL(port));
>  
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index 27dc903f0553..f034b7b0f1da 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -5684,6 +5684,8 @@ enum skl_power_gate {
>  /* Known as DDI_CTL_DE in MTL+ */
>  #define DDI_BUF_CTL(port) _MMIO_PORT(port, _DDI_BUF_CTL_A, _DDI_BUF_CTL_B)
>  #define  DDI_BUF_CTL_ENABLE			(1 << 31)
> +#define  XE2LPD_DDI_BUF_D2D_LINK_ENABLE		REG_BIT(29)
> +#define  XE2LPD_DDI_BUF_D2D_LINK_STATE		REG_BIT(28)
>  #define  DDI_BUF_TRANS_SELECT(n)	((n) << 24)
>  #define  DDI_BUF_EMP_MASK			(0xf << 24)
>  #define  DDI_BUF_PHY_LINK_RATE(r)		((r) << 20)
> -- 
> 2.43.0
> 

-- 
Matt Roper
Graphics Software Engineer
Linux GPU Platform Enablement
Intel Corporation