Re: [PATCH v5 10/13] drm/mediatek: Support CRC in display driver

[AngeloGioacchino Del Regno]

Il 15/02/24 11:11, Hsiao Chien Sung ha scritto:

Register CRC related function pointers to support
CRC retrieval.

Signed-off-by: Hsiao Chien Sung <shawn.s...@mediatek.com>
---
  drivers/gpu/drm/mediatek/mtk_drm_crtc.c     | 239 ++++++++++++++++++++
  drivers/gpu/drm/mediatek/mtk_drm_crtc.h     |  39 ++++
  drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h |   3 +
  3 files changed, 281 insertions(+)

diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c 
b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
index 14cf75fa217f9..6cb1ed419dee7 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
@@ -68,6 +68,9 @@ struct mtk_drm_crtc {
        /* lock for display hardware access */
        struct mutex                    hw_lock;
        bool                            config_updating;
+
+       struct mtk_ddp_comp             *crc_provider;
+       unsigned int                    frames;
  };

struct mtk_crtc_state {

@@ -635,6 +638,14 @@ static void mtk_crtc_ddp_irq(void *data)
        struct drm_crtc *crtc = data;
        struct mtk_drm_crtc *mtk_crtc = to_mtk_crtc(crtc);
        struct mtk_drm_private *priv = crtc->dev->dev_private;
+       struct mtk_ddp_comp *comp = mtk_crtc->crc_provider;
+
+       /*
+        * crc providers should make sure the crc is always correct
+        * by resetting it in .crc_read()
+        */
+       if (crtc->crc.opened)
+               comp->funcs->crc_read(comp->dev);

#if IS_REACHABLE(CONFIG_MTK_CMDQ)

        if (!priv->data->shadow_register && !mtk_crtc->cmdq_client.chan)
@@ -646,6 +657,24 @@ static void mtk_crtc_ddp_irq(void *data)
        if (!priv->data->shadow_register)
                mtk_crtc_ddp_config(crtc, NULL);
  #endif
+
+       /*
+        * drm_crtc_add_crc_entry() could take more than 50ms to finish
+        * put it at the end of the isr
+        */
+       if (crtc->crc.opened) {
+               /*
+                * skip the first crc because the first frame is configured by
+                * mtk_crtc_ddp_hw_init() when atomic enable
+                */
+               if (++mtk_crtc->frames > 1) {
+                       drm_crtc_add_crc_entry(crtc, true,
+                                              drm_crtc_vblank_count(crtc),
+                                              
comp->funcs->crc_entry(comp->dev));
+               }
+       } else {
+               mtk_crtc->frames = 0;
+       }
        mtk_drm_finish_page_flip(mtk_crtc);
  }

@@ -704,6 +733,40 @@ static void mtk_drm_crtc_update_output(struct drm_crtc *crtc,

        }
  }

+static int mtk_drm_crtc_set_crc_source(struct drm_crtc *crtc, const char *src)

+{
+       if (src && strcmp(src, "auto") != 0) {
+               DRM_ERROR("%s(crtc-%d): unknown source '%s'\n",
+                         __func__, drm_crtc_index(crtc), src);
+               return -EINVAL;
+       }
+       return 0;
+}
+
+static int mtk_drm_crtc_verify_crc_source(struct drm_crtc *crtc,
+                                         const char *src,
+                                         size_t *cnt)
+{
+       struct mtk_drm_crtc *mtk_crtc = to_mtk_crtc(crtc);
+       struct mtk_ddp_comp *comp = mtk_crtc->crc_provider;
+
+       if (!comp) {
+               DRM_ERROR("%s(crtc-%d): no crc provider\n",
+                         __func__, drm_crtc_index(crtc));
+               return -ENOENT;
+       }
+
+       if (src && strcmp(src, "auto") != 0) {
+               DRM_ERROR("%s(crtc-%d): unknown source '%s'\n",
+                         __func__, drm_crtc_index(crtc), src);
+               return -EINVAL;
+       }
+
+       *cnt = comp->funcs->crc_cnt(comp->dev);
+
+       return 0;
+}
+
  int mtk_drm_crtc_plane_check(struct drm_crtc *crtc, struct drm_plane *plane,
                             struct mtk_plane_state *state)
  {
@@ -841,6 +904,8 @@ static const struct drm_crtc_funcs mtk_crtc_funcs = {
        .atomic_destroy_state   = mtk_drm_crtc_destroy_state,
        .enable_vblank          = mtk_drm_crtc_enable_vblank,
        .disable_vblank         = mtk_drm_crtc_disable_vblank,
+       .set_crc_source         = mtk_drm_crtc_set_crc_source,
+       .verify_crc_source      = mtk_drm_crtc_verify_crc_source,
  };

static const struct drm_crtc_helper_funcs mtk_crtc_helper_funcs = {

@@ -1033,6 +1098,11 @@ int mtk_drm_crtc_create(struct drm_device *drm_dev,

if (comp->funcs->ctm_set)

                                has_ctm = true;
+
+                       if (comp->funcs->crc_cnt &&
+                           comp->funcs->crc_entry &&
+                           comp->funcs->crc_read)
+                               mtk_crtc->crc_provider = comp;
                }

mtk_ddp_comp_register_vblank_cb(comp, mtk_crtc_ddp_irq,

@@ -1137,3 +1207,172 @@ int mtk_drm_crtc_create(struct drm_device *drm_dev,

return 0;

  }
+
+void mtk_drm_crc_init(struct mtk_drm_crc *crc,
+                     const u32 *crc_offset_table, size_t crc_count,
+                     u32 reset_offset, u32 reset_mask)
+{
+       crc->ofs = crc_offset_table;
+       crc->cnt = crc_count;
+       crc->rst_ofs = reset_offset;
+       crc->rst_msk = reset_mask;
+       crc->va = kcalloc(crc->cnt, sizeof(*crc->va), GFP_KERNEL);
+       if (!crc->va) {
+               DRM_ERROR("failed to allocate memory for crc\n");
+               crc->cnt = 0;
+       }
+}
+
+void mtk_drm_crc_read(struct mtk_drm_crc *crc, void __iomem *reg)
+{

        u32 n; goes here

+       if (!crc->cnt || !crc->ofs || !crc->va)
+               return;
+
+#if IS_REACHABLE(CONFIG_MTK_CMDQ)
+       /* sync to see the most up-to-date copy of the DMA buffer */
+       dma_sync_single_for_cpu(crc->cmdq_client.chan->mbox->dev,
+                               crc->pa, crc->cnt * sizeof(*crc->va),
+                               DMA_FROM_DEVICE);
+#else
+       /* read crc with cpu for the platforms without cmdq */
+       {

then you don't need the braces.

Regards,
Angelo