Re: [PATCH v3 2/2] drm/tidss: Add support for AM625 DSS

From: Aradhya Bhatia
Date: Tue Aug 09 2022 - 02:09:14 EST


Hi Tomi,

On 28-Jul-22 17:34, Tomi Valkeinen wrote:
On 27/06/2022 18:12, Aradhya Bhatia wrote:
Add support for the DSS IP on TI's new AM625 SoC in the tidss driver.

Signed-off-by: Aradhya Bhatia <a-bhatia1@xxxxxx>
Reviewed-by: Rahul T R <r-ravikumar@xxxxxx>
---
  drivers/gpu/drm/tidss/tidss_dispc.c | 56 ++++++++++++++++++++++++++++-
  drivers/gpu/drm/tidss/tidss_dispc.h |  2 ++
  drivers/gpu/drm/tidss/tidss_drv.c   |  1 +
  3 files changed, 58 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/tidss/tidss_dispc.c b/drivers/gpu/drm/tidss/tidss_dispc.c
index dae47853b728..f084f0688a54 100644
--- a/drivers/gpu/drm/tidss/tidss_dispc.c
+++ b/drivers/gpu/drm/tidss/tidss_dispc.c
@@ -272,6 +272,55 @@ const struct dispc_features dispc_j721e_feats = {
      .vid_order = { 1, 3, 0, 2 },
  };
+const struct dispc_features dispc_am625_feats = {
+    .max_pclk_khz = {
+        [DISPC_VP_DPI] = 165000,
+        [DISPC_VP_OLDI] = 165000,
+    },
+
+    .scaling = {
+        .in_width_max_5tap_rgb = 1280,
+        .in_width_max_3tap_rgb = 2560,
+        .in_width_max_5tap_yuv = 2560,
+        .in_width_max_3tap_yuv = 4096,
+        .upscale_limit = 16,
+        .downscale_limit_5tap = 4,
+        .downscale_limit_3tap = 2,
+        /*
+         * The max supported pixel inc value is 255. The value
+         * of pixel inc is calculated like this: 1+(xinc-1)*bpp.
+         * The maximum bpp of all formats supported by the HW
+         * is 8. So the maximum supported xinc value is 32,
+         * because 1+(32-1)*8 < 255 < 1+(33-1)*4.
+         */
+        .xinc_max = 32,
+    },
+
+    .subrev = DISPC_AM625,
+
+    .common = "common",
+    .common_regs = tidss_am65x_common_regs,
+
+    .num_vps = 2,
+    .vp_name = { "vp1", "vp2" },
+    .ovr_name = { "ovr1", "ovr2" },
+    .vpclk_name =  { "vp1", "vp2" },
+    .vp_bus_type = { DISPC_VP_OLDI, DISPC_VP_DPI },

This looks correct, but with the two OLDI TXes, I think there will be some interesting issues.

The tidss_kms.c associates a DSS VP and a DT port, but that's no longer true if you add the ports for both OLDI TXes, as they both use the same VP. I think fixing that won't affect this patch, though, and merging this patch will, afaik, enable similar DSS functionality as we have for AM65x.

So, I think these two patches could be merged, or we could wait a bit until the OLDI situation becomes more clear. Up to you. In any case, for both patches:

Reviewed-by: Tomi Valkeinen <tomi.valkeinen@xxxxxxxxxxxxxxxx>\

Thank you for the review!

This patch set is required for the dss DT patches to be upstreamed for
the AM625-SK, so I would like them to get merged.

Since these were posted in the previous merge window, I will re-send with your tag.

Regards
Aradhya