[Intel-gfx] [PATCH v5 09/13] drm/i915/icl: Program TA_TIMING_PARAM registers
Chauhan, Madhav
madhav.chauhan at intel.com
Fri Jul 20 08:08:16 UTC 2018
> -----Original Message-----
> From: Ville Syrjälä [mailto:ville.syrjala at linux.intel.com]
> Sent: Thursday, July 19, 2018 9:51 PM
> To: Chauhan, Madhav <madhav.chauhan at intel.com>
> Cc: intel-gfx at lists.freedesktop.org; Nikula, Jani <jani.nikula at intel.com>;
> Zanoni, Paulo R <paulo.r.zanoni at intel.com>; Vivi, Rodrigo
> <rodrigo.vivi at intel.com>
> Subject: Re: [Intel-gfx] [PATCH v5 09/13] drm/i915/icl: Program
> TA_TIMING_PARAM registers
>
> On Tue, Jul 10, 2018 at 03:10:10PM +0530, Madhav Chauhan wrote:
> > This patch programs D-PHY timing parameters for the bus turn around
> > flow(in escape clocks) only if dsi link frequency <=800 MHz using
> > DPHY_TA_TIMING_PARAM and its identical register
> DSI_TA_TIMING_PARAM
> > (inside DSI Controller within the Display Core).
> >
> > Signed-off-by: Madhav Chauhan <madhav.chauhan at intel.com>
> > ---
> > drivers/gpu/drm/i915/icl_dsi.c | 21 +++++++++++++++++++++
> > drivers/gpu/drm/i915/intel_dsi.h | 1 +
> > drivers/gpu/drm/i915/intel_dsi_vbt.c | 1 +
> > 3 files changed, 23 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/i915/icl_dsi.c
> > b/drivers/gpu/drm/i915/icl_dsi.c index 832772d..8fd5284 100644
> > --- a/drivers/gpu/drm/i915/icl_dsi.c
> > +++ b/drivers/gpu/drm/i915/icl_dsi.c
> > @@ -302,6 +302,27 @@ static void gen11_dsi_setup_dphy_timings(struct
> intel_encoder *encoder)
> > I915_WRITE(DSI_DATA_TIMING_PARAM(port),
> > intel_dsi->dphy_data_lane_reg);
> > }
> > +
> > + /*
> > + * If DSI link operating at or below an 800 MHz,
> > + * TA_SURE should be override and programmed to
> > + * a value '0' inside TA_PARAM_REGISTERS otherwise
> > + * leave all fields at HW default values.
> > + */
> > + if (intel_dsi->bitrate_khz <= KHz(800)) {
>
> The KHz(800) confuses me. My brain thinks this value is 800 kHz when it's
> not. So I'd write it without the KHz() macro.
Ok. Initially I wrote without using KHz macro, but got comment to use KHz macro :)
Regards,
Madhav
>
> > + for_each_dsi_port(port, intel_dsi->ports) {
> > + tmp = I915_READ(DPHY_TA_TIMING_PARAM(port));
> > + tmp &= ~TA_SURE_TIME_MASK;
> > + tmp |= (TA_SURE_OVERRIDE | TA_SURE_TIME(0));
> > + I915_WRITE(DPHY_TA_TIMING_PARAM(port), tmp);
> > +
> > + /* shadow register inside display core */
> > + tmp = I915_READ(DSI_TA_TIMING_PARAM(port));
> > + tmp &= ~TA_SURE_TIME_MASK;
> > + tmp |= (TA_SURE_OVERRIDE | TA_SURE_TIME(0));
> > + I915_WRITE(DSI_TA_TIMING_PARAM(port), tmp);
> > + }
> > + }
> > }
> >
> > static void gen11_dsi_enable_port_and_phy(struct intel_encoder
> > *encoder) diff --git a/drivers/gpu/drm/i915/intel_dsi.h
> > b/drivers/gpu/drm/i915/intel_dsi.h
> > index 9fd8526..25e7396 100644
> > --- a/drivers/gpu/drm/i915/intel_dsi.h
> > +++ b/drivers/gpu/drm/i915/intel_dsi.h
> > @@ -101,6 +101,7 @@ struct intel_dsi {
> >
> > u16 init_count;
> > u32 pclk;
> > + u32 bitrate_khz;
> > u16 burst_mode_ratio;
> >
> > /* all delays in ms */
> > diff --git a/drivers/gpu/drm/i915/intel_dsi_vbt.c
> > b/drivers/gpu/drm/i915/intel_dsi_vbt.c
> > index 428290d..a9a98a4 100644
> > --- a/drivers/gpu/drm/i915/intel_dsi_vbt.c
> > +++ b/drivers/gpu/drm/i915/intel_dsi_vbt.c
> > @@ -589,6 +589,7 @@ bool intel_dsi_vbt_init(struct intel_dsi *intel_dsi,
> u16 panel_id)
> > intel_dsi->pclk = pclk;
> >
> > bitrate = (pclk * bpp) / intel_dsi->lane_count;
> > + intel_dsi->bitrate_khz = bitrate;
> >
> > switch (intel_dsi->escape_clk_div) {
> > case 0:
> > --
> > 2.7.4
> >
> > _______________________________________________
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> > Intel-gfx at lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/intel-gfx
>
> --
> Ville Syrjälä
> Intel
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