Re: [PATCH v2 10/25] drm/i915/xe2hpd: Add new C20 PLL register address

[Jani Nikula <jani.nikula@linux.intel.com>]

On Wed, 03 Apr 2024, Balasubramani Vivekanandan <balasubramani.vivekanandan@intel.com> wrote:
> Xe2_HPD has different address for C20 PLL registers. Enable the support
> to use the right PLL register address based on display version.
>
> Note that Xe2_LPD uses the same C20 SRAM offsets used by Xe_LPDP (i.e.
> MTL's display). According to the BSpec, currently, only Xe2_HPD has
> different offsets, so make sure it is the only display using them in the
> driver.

Even less of a fan of the register handling after seeing this patch.

BR,
Jani.

>
> Bspec: 67610
> Cc: Clint Taylor <Clinton.A.Taylor@intel.com>
> Cc: Gustavo Sousa <gustavo.sousa@intel.com>
> Signed-off-by: Balasubramani Vivekanandan <balasubramani.vivekanandan@intel.com>
> Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_cx0_phy.c  | 27 +++++++++++++++++--
>  .../gpu/drm/i915/display/intel_cx0_phy_regs.h |  9 +++++++
>  2 files changed, 34 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_cx0_phy.c b/drivers/gpu/drm/i915/display/intel_cx0_phy.c
> index caaae5d3758e..6e4647859fc6 100644
> --- a/drivers/gpu/drm/i915/display/intel_cx0_phy.c
> +++ b/drivers/gpu/drm/i915/display/intel_cx0_phy.c
> @@ -770,6 +770,17 @@ static struct intel_c20pll_reg mtl_c20_reg = {
>  	.mpllb_b = MTL_C20_B_MPLLB_CFG_ADDR
>  };
>  
> +static struct intel_c20pll_reg xe2hpd_c20_reg = {
> +	.tx_cnt_a = XE2HPD_C20_A_TX_CNTX_CFG_ADDR,
> +	.tx_cnt_b = XE2HPD_C20_B_TX_CNTX_CFG_ADDR,
> +	.cmn_cnt_a = XE2HPD_C20_A_CMN_CNTX_CFG_ADDR,
> +	.cmn_cnt_b = XE2HPD_C20_B_CMN_CNTX_CFG_ADDR,
> +	.mplla_a = XE2HPD_C20_A_MPLLA_CFG_ADDR,
> +	.mplla_b = XE2HPD_C20_B_MPLLA_CFG_ADDR,
> +	.mpllb_a = XE2HPD_C20_A_MPLLB_CFG_ADDR,
> +	.mpllb_b = XE2HPD_C20_B_MPLLB_CFG_ADDR,
> +};
> +
>  /* C20 basic DP 1.4 tables */
>  static const struct intel_c20pll_state mtl_c20_dp_rbr = {
>  	.clock = 162000,
> @@ -2166,19 +2177,29 @@ static int intel_c20pll_calc_port_clock(struct intel_encoder *encoder,
>  	return vco << tx_rate_mult >> tx_clk_div >> tx_rate;
>  }
>  
> +static struct intel_c20pll_reg *intel_c20_get_pll_reg(struct drm_i915_private *i915)
> +{
> +	if (DISPLAY_VER_FULL(i915) == IP_VER(14, 1))
> +		return &xe2hpd_c20_reg;
> +	else
> +		return &mtl_c20_reg;
> +}
> +
>  static void intel_c20pll_readout_hw_state(struct intel_encoder *encoder,
>  					  struct intel_c20pll_state *pll_state)
>  {
>  	bool cntx;
>  	intel_wakeref_t wakeref;
>  	int i;
> -	struct intel_c20pll_reg *pll_reg = &mtl_c20_reg;
> +	struct intel_c20pll_reg *pll_reg;
>  
>  	wakeref = intel_cx0_phy_transaction_begin(encoder);
>  
>  	/* 1. Read current context selection */
>  	cntx = intel_cx0_read(encoder, INTEL_CX0_LANE0, PHY_C20_VDR_CUSTOM_SERDES_RATE) & PHY_C20_CONTEXT_TOGGLE;
>  
> +	pll_reg = intel_c20_get_pll_reg(to_i915(encoder->base.dev));
> +
>  	/* Read Tx configuration */
>  	for (i = 0; i < ARRAY_SIZE(pll_state->tx); i++) {
>  		if (cntx)
> @@ -2353,7 +2374,7 @@ static void intel_c20_pll_program(struct drm_i915_private *i915,
>  	u32 clock = crtc_state->port_clock;
>  	bool cntx;
>  	int i;
> -	const struct intel_c20pll_reg *pll_reg = &mtl_c20_reg;
> +	const struct intel_c20pll_reg *pll_reg;
>  
>  	if (intel_crtc_has_dp_encoder(crtc_state))
>  		dp = true;
> @@ -2372,6 +2393,8 @@ static void intel_c20_pll_program(struct drm_i915_private *i915,
>  		usleep_range(4000, 4100);
>  	}
>  
> +	pll_reg = intel_c20_get_pll_reg(i915);
> +
>  	/* 3. Write SRAM configuration context. If A in use, write configuration to B context */
>  	/* 3.1 Tx configuration */
>  	for (i = 0; i < ARRAY_SIZE(pll_state->tx); i++) {
> 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 882b98dc347b..8e5fd605b99e 100644
> --- a/drivers/gpu/drm/i915/display/intel_cx0_phy_regs.h
> +++ b/drivers/gpu/drm/i915/display/intel_cx0_phy_regs.h
> @@ -292,6 +292,15 @@ struct intel_c20pll_reg {
>  #define MTL_C20_A_MPLLB_CFG_ADDR	0xCB5A
>  #define MTL_C20_B_MPLLB_CFG_ADDR	0xCB4E
>  
> +#define XE2HPD_C20_A_TX_CNTX_CFG_ADDR	0xCF5E
> +#define XE2HPD_C20_B_TX_CNTX_CFG_ADDR	0xCF5A
> +#define XE2HPD_C20_A_CMN_CNTX_CFG_ADDR	0xCE8E
> +#define XE2HPD_C20_B_CMN_CNTX_CFG_ADDR	0xCE89
> +#define XE2HPD_C20_A_MPLLA_CFG_ADDR	0xCE58
> +#define XE2HPD_C20_B_MPLLA_CFG_ADDR	0xCE4D
> +#define XE2HPD_C20_A_MPLLB_CFG_ADDR	0xCCC2
> +#define XE2HPD_C20_B_MPLLB_CFG_ADDR	0xCCB6
> +
>  /* C20 Phy VSwing Masks */
>  #define C20_PHY_VSWING_PREEMPH_MASK	REG_GENMASK8(5, 0)
>  #define C20_PHY_VSWING_PREEMPH(val)	REG_FIELD_PREP8(C20_PHY_VSWING_PREEMPH_MASK, val)

-- 
Jani Nikula, Intel