Re: [PATCH 32/67] drm/i915/cnl: DDI - PLL mapping

[Paulo Zanoni <paulo.r.zanoni@intel.com>]

Em Qui, 2017-04-06 às 12:15 -0700, Rodrigo Vivi escreveu:
> One of the steps for PLL (un)initialization is to (un)map
> the correspondent DDI that is actually using that PLL.
> 
> So, let's do this step following the places already stablished
> and used so far, although spec put this as part of PLL
> initialization sequences.
> 
> v2: Use proper prefix on bits names as suggested by Ander.
> v3: Add missed "~". Without that the logic was inverted
>     so we were disabling interrupts.
>     Credits-to: Clinton
>     Credits-to: Art
> v4: Spec is getting updated to do DDI -> PLL mapping
>     and clock on in 2 separated reg writes. (Paulo)
>     Also update bits definitions to use space
>     (1 << 1) instead of (1<<1). (Paulo)
> 
> Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
> Cc: Art Runyan <arthur.j.runyan@intel.com>
> Cc: Clint Taylor <clinton.a.taylor@intel.com>
> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
> Cc: Kahola, Mika <mika.kahola@intel.com>
> Cc: Ander Conselvan De Oliveira <ander.conselvan.de.oliveira@intel.co
> m>
> Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
> Reviewed-by: Kahola, Mika <mika.kahola@intel.com>
> Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
> ---
>  drivers/gpu/drm/i915/i915_reg.h  |  9 +++++++++
>  drivers/gpu/drm/i915/intel_ddi.c | 23 ++++++++++++++++++++---
>  2 files changed, 29 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_reg.h
> b/drivers/gpu/drm/i915/i915_reg.h
> index 3cfc65f..dcb8e21 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -8150,6 +8150,15 @@ enum {
>  #define DPLL_CFGCR1(id)	_MMIO_PIPE((id) - SKL_DPLL1,
> _DPLL1_CFGCR1, _DPLL2_CFGCR1)
>  #define DPLL_CFGCR2(id)	_MMIO_PIPE((id) - SKL_DPLL1,
> _DPLL1_CFGCR2, _DPLL2_CFGCR2)
>  
> +/*
> + * CNL Clocks
> + */
> +#define DPCLKA_CFGCR0				_MMIO(0x6C200)
> +#define  DPCLKA_CFGCR0_DDI_CLK_OFF(port)	(1 << ((port)+10))
> +#define  DPCLKA_CFGCR0_DDI_CLK_SEL_MASK(port)	(3 <<
> ((port)*2))
> +#define  DPCLKA_CFGCR0_DDI_CLK_SEL_SHIFT(port)	((port)*2)
> +#define  DPCLKA_CFGCR0_DDI_CLK_SEL(pll, port)	((pll) <<
> ((port)*2))
> +
>  /* BXT display engine PLL */
>  #define BXT_DE_PLL_CTL			_MMIO(0x6d000)
>  #define   BXT_DE_PLL_RATIO(x)		(x)	/*
> {60,65,100} * 19.2MHz */
> diff --git a/drivers/gpu/drm/i915/intel_ddi.c
> b/drivers/gpu/drm/i915/intel_ddi.c
> index 0914ad9..2a901bf 100644
> --- a/drivers/gpu/drm/i915/intel_ddi.c
> +++ b/drivers/gpu/drm/i915/intel_ddi.c
> @@ -1621,13 +1621,27 @@ static void intel_ddi_clk_select(struct
> intel_encoder *encoder,
>  {
>  	struct drm_i915_private *dev_priv = to_i915(encoder-
> >base.dev);
>  	enum port port = intel_ddi_get_encoder_port(encoder);
> +	uint32_t val;
>  
>  	if (WARN_ON(!pll))
>  		return;
>  
> -	if (IS_GEN9_BC(dev_priv)) {
> -		uint32_t val;
> +	if (IS_CANNONLAKE(dev_priv)) {
> +		/* Configure DPCLKA_CFGCR0 to map the DPLL to the
> DDI. */
> +		val = I915_READ(DPCLKA_CFGCR0);
> +		val |= DPCLKA_CFGCR0_DDI_CLK_SEL(pll->id, port);
> +		I915_WRITE(DPCLKA_CFGCR0, val);

A question to the Atomic Lords: don't we need some sort of locking
around this register since it's used by all ports/clocks? I suppose
dev_priv->dpll_lock would do...

Maybe the same would apply for gen9_bc.

>  
> +		/*
> +		 * Configure DPCLKA_CFGCR0 to turn on the clock for
> the DDI.
> +		 * This step and the step before must be done with
> separate
> +		 * register writes.
> +		 */
> +		val = I915_READ(DPCLKA_CFGCR0);
> +		val &= ~(DPCLKA_CFGCR0_DDI_CLK_OFF(port) |
> +			 DPCLKA_CFGCR0_DDI_CLK_SEL_MASK(port));
> +		I915_WRITE(DPCLKA_CFGCR0, val);
> +	} else if (IS_GEN9_BC(dev_priv)) {
>  		/* DDI -> PLL mapping  */
>  		val = I915_READ(DPLL_CTRL2);
>  
> @@ -1763,7 +1777,10 @@ static void intel_ddi_post_disable(struct
> intel_encoder *intel_encoder,
>  	if (dig_port)
>  		intel_display_power_put(dev_priv, dig_port-
> >ddi_io_power_domain);
>  
> -	if (IS_GEN9_BC(dev_priv))
> +	if (IS_CANNONLAKE(dev_priv))
> +		I915_WRITE(DPCLKA_CFGCR0, I915_READ(DPCLKA_CFGCR0) |
> +			   DPCLKA_CFGCR0_DDI_CLK_OFF(port));
> +	else if (IS_GEN9_BC(dev_priv))
>  		I915_WRITE(DPLL_CTRL2, (I915_READ(DPLL_CTRL2) |
>  					DPLL_CTRL2_DDI_CLK_OFF(port)
> ));
>  	else if (INTEL_GEN(dev_priv) < 9)
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