[PATCH v2] drm: Add DPCD definitions for DP 1.4 DSC feature

Navare, Manasi D manasi.d.navare at intel.com
Wed Feb 22 01:12:21 UTC 2017


On Fri, 17 Feb 2017, Manasi Navare <manasi.d.navare at intel.com> wrote:
> Display stream compression is supported on DP 1.4 DP devices. This 
> patch adds the corersponding DPCD register definitions for DSC.
>
> v2:
> * Rebased on drm-tip
>
> Signed-off-by: Manasi Navare <manasi.d.navare at intel.com>
> Cc: Jani Nikula <jani.nikula at linux.intel.com>
> Cc: Paulo Zanoni <paulo.r.zanoni at intel.com>
> Cc: dri-devel at lists.freedesktop.org

Tedious work to cross check this stuff against the spec... found one real issue; while at it please fix a few nitpicks that I would otherwise have ignored.

BR,
Jani.


> ---
>  include/drm/drm_dp_helper.h | 102 
> ++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 102 insertions(+)
>
> diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h 
> index ba89295..4c1fc26 100644
> --- a/include/drm/drm_dp_helper.h
> +++ b/include/drm/drm_dp_helper.h
> @@ -179,6 +179,108 @@
>  
>  #define DP_GUID				    0x030   /* 1.2 */
>  
> +#define DP_DSC_SUPPORT                      0x060   /* DP 1.4 */
> +# define DP_DSC_DECOMPRESSION_IS_SUPPORTED  (1 << 0)
> +
> +#define DP_DSC_REV                          0x061
> +# define DP_DSC_MAJOR_MASK                  (15 << 0)
> +# define DP_DSC_MINOR_MASK                  (15 << 4)
> +# define DP_DSC_MINOR_SHIFT                 4

Nitpick: Hex is preferred for masks. Same for all masks below. MAJOR_SHIFT for completeness.

So should I add the MAJOR_SHIFT as well even though it will just 0?


> +
> +#define DP_DSC_RC_BUF_BLK_SIZE              0x062
> +# define DP_DSC_RC_BUF_BLK_SIZE_1           0x0
> +# define DP_DSC_RC_BUF_BLK_SIZE_4           0x1
> +# define DP_DSC_RC_BUF_BLK_SIZE_16          0x2
> +# define DP_DSC_RC_BUF_BLK_SIZE_64          0x3
> +
> +#define DP_DSC_RC_BUF_SIZE                  0x063
> +
> +#define DP_DSC_SLICE_CAP_1                  0x064
> +# define DP_DSC_1_PER_DP_DSC_SINK           (1 << 0)
> +# define DP_DSC_2_PER_DP_DSC_SINK           (1 << 1)
> +# define DP_DSC_4_PER_DP_DSC_SINK           (1 << 3)
> +# define DP_DSC_6_PER_DP_DSC_SINK           (1 << 4)
> +# define DP_DSC_8_PER_DP_DSC_SINK           (1 << 5)
> +# define DP_DSC_10_PER_DP_DSC_SINK          (1 << 6)
> +# define DP_DSC_12_PER_DP_DSC_SINK          (1 << 7)
> +
> +#define DP_DSC_LINE_BUF_BIT_DEPTH           0x065
> +# define DP_DSC_LINE_BUF_BIT_DEPTH_MASK     (15 << 0)
> +# define DP_DSC_LINE_BUF_BIT_DEPTH_9        0x0
> +# define DP_DSC_LINE_BUF_BIT_DEPTH_10       0x1
> +# define DP_DSC_LINE_BUF_BIT_DEPTH_11       0x2
> +# define DP_DSC_LINE_BUF_BIT_DEPTH_12       0x3
> +# define DP_DSC_LINE_BUF_BIT_DEPTH_13       0x4
> +# define DP_DSC_LINE_BUF_BIT_DEPTH_14       0x5
> +# define DP_DSC_LINE_BUF_BIT_DEPTH_15       0x6
> +# define DP_DSC_LINE_BUF_BIT_DEPTH_16       0x7
> +# define DP_DSC_LINE_BUF_BIT_DEPTH_8        0x8
> +
> +#define DP_DSC_BLK_PREDICTION_SUPPORT       0x066
> +# define DP_DSC_BLK_PREDICTION_IS_SUPPORTED (1 << 0)
> +
> +#define DP_DSC_MAX_BITS_PER_PIXEL_LOW       0x067   /* eDP 1.4 */
> +
> +#define DP_DSC_MAX_BITS_PER_PIXEL_HI        0x068   /* eDP 1.4 */
> +
> +#define DP_DSC_DEC_COLOR_FORMAT_CAP         0x069
> +# define DP_DSC_RGB                         (1 << 0)
> +# define DP_DSC_YCbCr444                    (1 << 1)
> +# define DP_DSC_YCbCr422_Simple             (1 << 2)
> +# define DP_DSC_YCbCr422_Native             (1 << 3)
> +# define DP_DSC_YCbCr420_Native             (1 << 4)
> +
> +#define DP_DSC_DEC_COLOR_DEPTH_CAP          0x06A
> +# define DP_DSC_8_BPC                       (1 << 1)
> +# define DP_DSC_10_BPC                      (1 << 2)
> +# define DP_DSC_12_BPC                      (1 >> 3)

Oops, shifting to wrong direction!

Oops, yes that is my mistake, I will fix the shift direction.

> +
> +#define DP_DSC_PEAK_THROUGHPUT              0x06B
> +# define DP_DSC_THROUGHPUT_MODE_0_340       0x1
> +# define DP_DSC_THROUGHPUT_MODE_0_400       0x2
> +# define DP_DSC_THROUGHPUT_MODE_0_450       0x3
> +# define DP_DSC_THROUGHPUT_MODE_0_500       0x4
> +# define DP_DSC_THROUGHPUT_MODE_0_550       0x5
> +# define DP_DSC_THROUGHPUT_MODE_0_600       0x6
> +# define DP_DSC_THROUGHPUT_MODE_0_650       0x7
> +# define DP_DSC_THROUGHPUT_MODE_0_700       0x8
> +# define DP_DSC_THROUGHPUT_MODE_0_750       0x9
> +# define DP_DSC_THROUGHPUT_MODE_0_800       0xA
> +# define DP_DSC_THROUGHPUT_MODE_0_850       0xB
> +# define DP_DSC_THROUGHPUT_MODE_0_900       0xC
> +# define DP_DSC_THROUGHPUT_MODE_0_950       0xD
> +# define DP_DSC_THROUGHPUT_MODE_0_1000      0xE

Nitpick: MODE_0_MASK and MODE_0_SHIFT for completeness. Seems inconsistent to use hex for MODE_0 values and dec for MODE_1 values.

For Mode 0, it would be all these values shifted by 0, should I add the shifts by 0 for consistency with 
MODE_1?
And yes I will add MODE_0 MASK and SHIFT.

Regards
Manasi

> +# define DP_DSC_THROUGHPUT_MODE_1_MASK      (15 << 4)
> +# define DP_DSC_THROUGHPUT_MODE_1_SHIFT     4
> +# define DP_DSC_THROUGHPUT_MODE_1_340       (1 << 4)
> +# define DP_DSC_THROUGHPUT_MODE_1_400       (2 << 4)
> +# define DP_DSC_THROUGHPUT_MODE_1_450       (3 << 4)
> +# define DP_DSC_THROUGHPUT_MODE_1_500       (4 << 4)
> +# define DP_DSC_THROUGHPUT_MODE_1_550       (5 << 4)
> +# define DP_DSC_THROUGHPUT_MODE_1_600       (6 << 4)
> +# define DP_DSC_THROUGHPUT_MODE_1_650       (7 << 4)
> +# define DP_DSC_THROUGHPUT_MODE_1_700       (8 << 4)
> +# define DP_DSC_THROUGHPUT_MODE_1_750       (9 << 4)
> +# define DP_DSC_THROUGHPUT_MODE_1_800       (10 << 4)
> +# define DP_DSC_THROUGHPUT_MODE_1_850       (11 << 4)
> +# define DP_DSC_THROUGHPUT_MODE_1_900       (12 << 4)
> +# define DP_DSC_THROUGHPUT_MODE_1_950       (13 << 4)
> +# define DP_DSC_THROUGHPUT_MODE_1_1000      (14 << 4)
> +
> +#define DP_DSC_MAX_SLICE_WIDTH              0x06C
> +
> +#define DP_DSC_SLICE_CAP_2                  0x06D
> +# define DP_DSC_16_PER_DP_DSC_SINK          (1 << 0)
> +# define DP_DSC_20_PER_DP_DSC_SINK          (1 << 1)
> +# define DP_DSC_24_PER_DP_DSC_SINK          (1 << 2)
> +
> +#define DP_DSC_BITS_PER_PIXEL_INC           0x06F
> +# define DP_DSC_BITS_PER_PIXEL_1_16         0x0
> +# define DP_DSC_BITS_PER_PIXEL_1_8          0x1
> +# define DP_DSC_BITS_PER_PIXEL_1_4          0x2
> +# define DP_DSC_BITS_PER_PIXEL_1_2          0x3
> +# define DP_DSC_BITS_PER_PIXEL_1            0x4
> +
>  #define DP_PSR_SUPPORT                      0x070   /* XXX 1.2? */
>  # define DP_PSR_IS_SUPPORTED                1
>  # define DP_PSR2_IS_SUPPORTED		    2	    /* eDP 1.4 */

--
Jani Nikula, Intel Open Source Technology Center


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