[Intel-gfx] [PATCH 04/20] drm/i915/icl: Enable DSI IO power

[Chauhan, Madhav]

> -----Original Message-----
> From: Nikula, Jani
> Sent: Monday, July 2, 2018 3:53 PM
> To: Chauhan, Madhav <madhav.chauhan at intel.com>; intel-
> gfx at lists.freedesktop.org
> Cc: Zanoni, Paulo R <paulo.r.zanoni at intel.com>; Shankar, Uma
> <uma.shankar at intel.com>; Vivi, Rodrigo <rodrigo.vivi at intel.com>
> Subject: RE: [PATCH 04/20] drm/i915/icl: Enable DSI IO power
> 
> On Mon, 02 Jul 2018, "Chauhan, Madhav" <madhav.chauhan at intel.com>
> wrote:
> >> -----Original Message-----
> >> From: Nikula, Jani
> >> Sent: Monday, July 2, 2018 3:27 PM
> >> To: Chauhan, Madhav <madhav.chauhan at intel.com>; intel-
> >> gfx at lists.freedesktop.org
> >> Cc: Zanoni, Paulo R <paulo.r.zanoni at intel.com>; Shankar, Uma
> >> <uma.shankar at intel.com>; Vivi, Rodrigo <rodrigo.vivi at intel.com>;
> >> Chauhan, Madhav <madhav.chauhan at intel.com>
> >> Subject: Re: [PATCH 04/20] drm/i915/icl: Enable DSI IO power
> >>
> >> On Fri, 15 Jun 2018, Madhav Chauhan <madhav.chauhan at intel.com>
> wrote:
> >> > This patch configures mode of operation for DSI and enable DDI IO
> >> > power by configuring power well.
> >> >
> >> > Signed-off-by: Madhav Chauhan <madhav.chauhan at intel.com>
> >> > ---
> >> >  drivers/gpu/drm/i915/intel_dsi_new.c | 22 ++++++++++++++++++++++
> >> >  1 file changed, 22 insertions(+)
> >> >
> >> > diff --git a/drivers/gpu/drm/i915/intel_dsi_new.c
> >> > b/drivers/gpu/drm/i915/intel_dsi_new.c
> >> > index 0d325ca..5ec4016 100644
> >> > --- a/drivers/gpu/drm/i915/intel_dsi_new.c
> >> > +++ b/drivers/gpu/drm/i915/intel_dsi_new.c
> >> > @@ -55,11 +55,33 @@ static void
> >> > gen11_dsi_program_esc_clk_div(struct
> >> intel_encoder *encoder)
> >> >  	}
> >> >  }
> >> >
> >> > +static void gen11_dsi_enable_io_power(struct intel_encoder
> >> > +*encoder) {
> >> > +	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
> >> > +	struct intel_dsi *intel_dsi = enc_to_intel_dsi(&encoder->base);
> >> > +	enum port port;
> >> > +	u32 tmp;
> >> > +
> >> > +	for_each_dsi_port(port, intel_dsi->ports) {
> >> > +		tmp = I915_READ(ICL_DSI_IO_MODECTL(port));
> >> > +		tmp |= COMBO_PHY_MODE_DSI;
> >> > +		I915_WRITE(ICL_DSI_IO_MODECTL(port), tmp);
> >> > +	}
> >> > +
> >> > +	intel_display_power_get(dev_priv,
> >> POWER_DOMAIN_PORT_DDI_A_IO);
> >> > +
> >> > +	if (intel_dsi->dual_link)
> >> > +		intel_display_power_get(dev_priv,
> >> POWER_DOMAIN_PORT_DDI_B_IO);
> >>
> >> Per bspec, "DSI0 uses DDI A; DSI1 uses DDI B" so shouldn't this be a
> >> for_each_dsi_port() too, with the appropriate mapping to power domain?
> >
> > Do you mean something like this:
> >
> > enum intel_display_power_domain power_domain;
> > for_each_dsi_port()
> > {
> > 	if (port ==PORT_A)
> > 		power_domain = POWER_DOMAIN_PORT_DDI_A_IO;
> > 	else if( port == PORT_B)
> > 		power_domain = POWER_DOMAIN_PORT_DDI_A_IO;
> >
> > 	intel_display_power_get(dev_priv, power_domain); }
> 
> That's my understanding of the spec, yes. Maybe simply:
> 
> 	for_each_dsi_port() {
>         	intel_display_power_get(port == PORT_A ?
> 					POWER_DOMAIN_PORT_DDI_A_IO :
>                                         POWER_DOMAIN_PORT_DDI_B_IO)
>         }

Agree, power domain should not be hardcoded just on the basis of intel_dsi->dual_link.
Wanted to have this change earlier but forgot to add while patches published :)

Regards,
Madhav

> 
> BR,
> Jani.
> 
> 
> >
> >>
> >> > +}
> >> > +
> >> >  static void __attribute__((unused)) gen11_dsi_pre_enable(
> >> >  				struct intel_encoder *encoder,
> >> >  				const struct intel_crtc_state *pipe_config,
> >> >  				const struct drm_connector_state
> >> *conn_state)
> >>
> >> Please don't end lines in (. You can add a newline before the
> >> function
> >> name:
> >>
> >> static void __attribute__((unused))
> >> gen11_dsi_pre_enable(struct intel_encoder *encoder,
> >> 		     const struct intel_crtc_state *pipe_config,
> >> 		     const struct drm_connector_state *conn_state)
> >>
> >
> > Got it. Thanks!!
> >
> > Regards,
> > Madhav
> >
> >> >  {
> >> > +	/* step2: enable IO power */
> >> > +	gen11_dsi_enable_io_power(encoder);
> >> > +
> >> >  	/* step3: enable DSI PLL */
> >> >  	gen11_dsi_program_esc_clk_div(encoder);
> >> >  }
> >>
> >> --
> >> Jani Nikula, Intel Open Source Graphics Center
> 
> --
> Jani Nikula, Intel Open Source Graphics Center