drm/vc4: Add debugfs node that dumps the vc5 gamma PWL entries

This helps with debugging the conversion from a 256 point gamma LUT to
16 point PWL entries as used by the BCM2711.

Co-developed-by: Juerg Haefliger <juergh@canonical.com>
Signed-off-by: Juerg Haefliger <juergh@canonical.com>
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>

diff --git a/drivers/gpu/drm/vc4/vc4_hvs.c b/drivers/gpu/drm/vc4/vc4_hvs.c
index c4851e1..941c7e3 100644 (file)
--- a/drivers/gpu/drm/vc4/vc4_hvs.c
+++ b/drivers/gpu/drm/vc4/vc4_hvs.c
@@ -134,6 +134,84 @@ static int vc4_hvs_debugfs_dlist(struct seq_file *m, void *data)
        return 0;
 }
 
+static int vc5_hvs_debugfs_gamma(struct seq_file *m, void *data)
+{
+       struct drm_info_node *node = m->private;
+       struct drm_device *dev = node->minor->dev;
+       struct vc4_dev *vc4 = to_vc4_dev(dev);
+       struct drm_printer p = drm_seq_file_printer(m);
+       unsigned int i, chan;
+       u32 dispstat, dispbkgndx;
+
+       for (chan = 0; chan < SCALER_CHANNELS_COUNT; chan++) {
+               u32 x_c, grad;
+               u32 offset = SCALER5_DSPGAMMA_START +
+                       chan * SCALER5_DSPGAMMA_CHAN_OFFSET;
+
+               dispstat = VC4_GET_FIELD(HVS_READ(SCALER_DISPSTATX(chan)),
+                                        SCALER_DISPSTATX_MODE);
+               if (dispstat == SCALER_DISPSTATX_MODE_DISABLED ||
+                   dispstat == SCALER_DISPSTATX_MODE_EOF) {
+                       drm_printf(&p, "HVS channel %u: Channel disabled\n", chan);
+                       continue;
+               }
+
+               dispbkgndx = HVS_READ(SCALER_DISPBKGNDX(chan));
+               if (!(dispbkgndx & SCALER_DISPBKGND_GAMMA)) {
+                       drm_printf(&p, "HVS channel %u: Gamma disabled\n", chan);
+                       continue;
+               }
+
+               drm_printf(&p, "HVS channel %u:\n", chan);
+               drm_printf(&p, "  red:\n");
+               for (i = 0; i < SCALER5_DSPGAMMA_NUM_POINTS; i++, offset += 8) {
+                       x_c = HVS_READ(offset);
+                       grad = HVS_READ(offset + 4);
+                       drm_printf(&p, "  %08x %08x - x %u, c %u, grad %u\n",
+                                  x_c, grad,
+                                  VC4_GET_FIELD(x_c, SCALER5_DSPGAMMA_OFF_X),
+                                  VC4_GET_FIELD(x_c, SCALER5_DSPGAMMA_OFF_C),
+                                  grad);
+               }
+               drm_printf(&p, "  green:\n");
+               for (i = 0; i < SCALER5_DSPGAMMA_NUM_POINTS; i++, offset += 8) {
+                       x_c = HVS_READ(offset);
+                       grad = HVS_READ(offset + 4);
+                       drm_printf(&p, "  %08x %08x - x %u, c %u, grad %u\n",
+                                  x_c, grad,
+                                  VC4_GET_FIELD(x_c, SCALER5_DSPGAMMA_OFF_X),
+                                  VC4_GET_FIELD(x_c, SCALER5_DSPGAMMA_OFF_C),
+                                  grad);
+               }
+               drm_printf(&p, "  blue:\n");
+               for (i = 0; i < SCALER5_DSPGAMMA_NUM_POINTS; i++, offset += 8) {
+                       x_c = HVS_READ(offset);
+                       grad = HVS_READ(offset + 4);
+                       drm_printf(&p, "  %08x %08x - x %u, c %u, grad %u\n",
+                                  x_c, grad,
+                                  VC4_GET_FIELD(x_c, SCALER5_DSPGAMMA_OFF_X),
+                                  VC4_GET_FIELD(x_c, SCALER5_DSPGAMMA_OFF_C),
+                                  grad);
+               }
+
+               /* Alpha only valid on channel 2 */
+               if (chan != 2)
+                       continue;
+
+               drm_printf(&p, "  alpha:\n");
+               for (i = 0; i < SCALER5_DSPGAMMA_NUM_POINTS; i++, offset += 8) {
+                       x_c = HVS_READ(offset);
+                       grad = HVS_READ(offset + 4);
+                       drm_printf(&p, "  %08x %08x - x %u, c %u, grad %u\n",
+                                  x_c, grad,
+                                  VC4_GET_FIELD(x_c, SCALER5_DSPGAMMA_OFF_X),
+                                  VC4_GET_FIELD(x_c, SCALER5_DSPGAMMA_OFF_C),
+                                  grad);
+               }
+       }
+       return 0;
+}
+
 /* The filter kernel is composed of dwords each containing 3 9-bit
  * signed integers packed next to each other.
  */
@@ -795,6 +873,9 @@ static int vc4_hvs_bind(struct device *dev, struct device *master, void *data)
                             NULL);
        vc4_debugfs_add_file(drm, "hvs_dlists", vc4_hvs_debugfs_dlist,
                             NULL);
+       if (hvs->hvs5)
+               vc4_debugfs_add_file(drm, "hvs_gamma", vc5_hvs_debugfs_gamma,
+                                    NULL);
 
        return 0;
 }