[Intel-gfx] [PATCH 20/20] drm/i915/mtl: Pin assignment for TypeC

[Kahola, Mika]

> -----Original Message-----
> From: Deak, Imre <imre.deak at intel.com>
> Sent: Wednesday, October 26, 2022 5:27 PM
> To: Kahola, Mika <mika.kahola at intel.com>
> Cc: intel-gfx at lists.freedesktop.org; Srivatsa, Anusha
> <anusha.srivatsa at intel.com>; Roper, Matthew D
> <matthew.d.roper at intel.com>; Souza, Jose <jose.souza at intel.com>
> Subject: Re: [PATCH 20/20] drm/i915/mtl: Pin assignment for TypeC
> 
> On Fri, Oct 14, 2022 at 03:47:40PM +0300, Mika Kahola wrote:
> > From: Anusha Srivatsa <anusha.srivatsa at intel.com>
> >
> > Unlike previous platforms that used PORT_TX_DFLEXDPSP for max_lane
> > calculation, MTL uses only PORT_TX_DFLEXPA1 from which the max_lanes
> > has to be calculated.
> >
> > Bspec: 50235, 65380
> > Cc: Mika Kahola <mika.kahola at intel.com>
> > Cc: Imre Deak <imre.deak at intel.com>
> > Cc: Matt Roper <matthew.d.roper at intel.com>
> > Signed-off-by: Anusha Srivatsa <anusha.srivatsa at intel.com>
> > Signed-off-by: Jose Roberto de Souza <jose.souza at intel.com>
> > ---
> >  drivers/gpu/drm/i915/display/intel_tc.c | 30
> > +++++++++++++++++++++++++
> >  1 file changed, 30 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/i915/display/intel_tc.c
> > b/drivers/gpu/drm/i915/display/intel_tc.c
> > index dba10bcc6b66..1bc81adf1ad7 100644
> > --- a/drivers/gpu/drm/i915/display/intel_tc.c
> > +++ b/drivers/gpu/drm/i915/display/intel_tc.c
> > @@ -13,6 +13,10 @@
> >  #include "intel_tc.h"
> >  #include "intel_tc_phy_regs.h"
> >
> > +#define DP_PIN_ASSIGNMENT_C	0x3
> > +#define DP_PIN_ASSIGNMENT_D	0x4
> > +#define DP_PIN_ASSIGNMENT_E	0x5
> 
> The above are flags for the PORT_TX_DFLEXPA1 register, so should be defined
> next to it.
Ok. I will move these defines to the correct place.

> 
> TGL handles a few more encodings, not sure if that's correct or the register
> description, opened a bspec ticket to clarify that.
> 
> > +
> >  static const char *tc_port_mode_name(enum tc_port_mode mode)  {
> >  	static const char * const names[] = { @@ -149,6 +153,29 @@ u32
> > intel_tc_port_get_pin_assignment_mask(struct intel_digital_port *dig_port)
> >  	       DP_PIN_ASSIGNMENT_SHIFT(dig_port->tc_phy_fia_idx);
> >  }
> >
> > +static int mtl_tc_port_get_pin_assignment_mask(struct
> > +intel_digital_port *dig_port)
> 
> The function returns the maximum number of lanes, so should be named
> accordingly.

Yes, I will figure out a different name for that function.

> 
> > +{
> > +	struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
> > +	intel_wakeref_t wakeref;
> > +	u32 pin_mask;
> > +
> > +	assert_tc_cold_blocked(dig_port);
> > +
> > +	with_intel_display_power(i915, POWER_DOMAIN_DISPLAY_CORE,
> wakeref)
> > +		pin_mask = intel_tc_port_get_pin_assignment_mask(dig_port);
> 
> The called function handles all the above, so it can be just:
> 
> 	switch (intel_tc_port_get_pin_assignment_mask()):

Yes. This simplifies the code a bit.

Thanks for a review and comments!

Cheers,
Mika
> 
> > +
> > +	switch(pin_mask) {
> > +	default:
> > +		MISSING_CASE(pin_mask);
> > +		fallthrough;
> > +	case DP_PIN_ASSIGNMENT_D:
> > +		return 2;
> > +	case DP_PIN_ASSIGNMENT_C:
> > +	case DP_PIN_ASSIGNMENT_E:
> > +		return 4;
> > +	}
> > +}
> > +
> >  int intel_tc_port_fia_max_lane_count(struct intel_digital_port
> > *dig_port)  {
> >  	struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev); @@
> > -158,6 +185,9 @@ int intel_tc_port_fia_max_lane_count(struct
> intel_digital_port *dig_port)
> >  	if (dig_port->tc_mode != TC_PORT_DP_ALT)
> >  		return 4;
> >
> > +	if (DISPLAY_VER(i915) >= 14)
> > +		return mtl_tc_port_get_pin_assignment_mask(dig_port);
> > +
> >  	assert_tc_cold_blocked(dig_port);
> >
> >  	lane_mask = 0;
> > --
> > 2.34.1
> >