[PATCH V2] drm: Add LTTPR defines for DP 1.4a

Siqueira, Rodrigo Rodrigo.Siqueira at amd.com
Wed Aug 28 19:58:57 UTC 2019


On 08/27, Jani Nikula wrote:
> On Mon, 26 Aug 2019, "Siqueira, Rodrigo" <Rodrigo.Siqueira at amd.com> wrote:
> > DP 1.4a specification defines Link Training Tunable PHY Repeater (LTTPR)
> > which is required to add support for systems with Thunderbolt or other
> > repeater devices.
> >
> > Changes since V1:
> > - Adjusts registers names to be aligned with spec and the rest of the
> >   file
> > - Update spec comment from 1.4 to 1.4a
> >
> > Cc: Abdoulaye Berthe <Abdoulaye.Berthe at amd.com>
> > Cc: Harry Wentland <harry.wentland at amd.com>
> > Cc: Leo Li <sunpeng.li at amd.com>
> > Signed-off-by: Rodrigo Siqueira <Rodrigo.Siqueira at amd.com>
> > Signed-off-by: Abdoulaye Berthe <Abdoulaye.Berthe at amd.com>
> > ---
> >  include/drm/drm_dp_helper.h | 25 +++++++++++++++++++++++++
> >  1 file changed, 25 insertions(+)
> >
> > diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
> > index 8364502f92cf..e8beb4e7e5da 100644
> > --- a/include/drm/drm_dp_helper.h
> > +++ b/include/drm/drm_dp_helper.h
> > @@ -134,6 +134,31 @@
> >  #define DP_SUPPORTED_LINK_RATES		    0x010 /* eDP 1.4 */
> >  # define DP_MAX_SUPPORTED_RATES		     8	    /* 16-bit little-endian */
> >  
> > +/** Link Training (LT)-tunable Physical Repeaters - DP 1.4a **/
> 
> This is not a kernel-doc comment, so please drop the double ** and use
> regular comments.
> 
> All the DPCD register definitions are ordered according to register
> offset. Why add 0xf0000 and friends between 0x10 and 0x20...?

Hi Jani,

Thank you for the feedback. I already sent a V3 patch based on your
comments; please let me know if you have any other suggestion.

Best Regards

> BR,
> Jani.
> 
> > +#define DP_LT_TUNABLE_PHY_REPEATER_FIELD_DATA_STRUCTURE_REV 0xf0000
> > +#define DP_MAX_LINK_RATE_PHY_REPEATER                       0xf0001
> > +#define DP_PHY_REPEATER_CNT                                 0xf0002
> > +#define DP_PHY_REPEATER_MODE                                0xf0003
> > +#define DP_MAX_LANE_COUNT_PHY_REPEATER                      0xf0004
> > +#define DP_PHY_REPEATER_EXTENDED_WAIT_TIMEOUT               0xf0005
> > +#define DP_TRAINING_PATTERN_SET_PHY_REPEATER1               0xf0010
> > +#define DP_TRAINING_LANE0_SET_PHY_REPEATER1                 0xf0011
> > +#define DP_TRAINING_LANE1_SET_PHY_REPEATER1                 0xf0012
> > +#define DP_TRAINING_LANE2_SET_PHY_REPEATER1                 0xf0013
> > +#define DP_TRAINING_LANE3_SET_PHY_REPEATER1                 0xf0014
> > +#define DP_TRAINING_AUX_RD_INTERVAL_PHY_REPEATER1           0xf0020
> > +#define DP_TRANSMITTER_CAPABILITY_PHY_REPEATER1             0xf0021
> > +#define DP_LANE0_1_STATUS_PHY_REPEATER1                     0xf0030
> > +#define DP_LANE2_3_STATUS_PHY_REPEATER1                     0xf0031
> > +#define DP_LANE_ALIGN_STATUS_UPDATED_PHY_REPEATER1          0xf0032
> > +#define DP_ADJUST_REQUEST_LANE0_1_PHY_REPEATER1             0xf0033
> > +#define DP_ADJUST_REQUEST_LANE2_3_PHY_REPEATER1             0xf0034
> > +#define DP_SYMBOL_ERROR_COUNT_LANE0_PHY_REPEATER1           0xf0035
> > +#define DP_SYMBOL_ERROR_COUNT_LANE1_PHY_REPEATER1           0xf0037
> > +#define DP_SYMBOL_ERROR_COUNT_LANE2_PHY_REPEATER1           0xf0039
> > +#define DP_SYMBOL_ERROR_COUNT_LANE3_PHY_REPEATER1           0xf003b
> > +#define DP_FEC_STATUS_PHY_REPEATER1                         0xf0290
> > +
> >  /* Multiple stream transport */
> >  #define DP_FAUX_CAP			    0x020   /* 1.2 */
> >  # define DP_FAUX_CAP_1			    (1 << 0)
> 
> -- 
> Jani Nikula, Intel Open Source Graphics Center

-- 
Rodrigo Siqueira
Software Engineer, Advanced Micro Devices (AMD)
https://siqueira.tech
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