drm/msm/dp: Allow sub-regions to be specified in DT

Not all platforms has P0 at an offset of 0x1000 from the base address,
so add support for specifying each sub-region in DT. The code falls back
to the predefined offsets in the case that only a single reg is
specified, in order to support existing DT.
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Abhinav Kumar <abhinavk@codeaurora.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20211001174400.981707-6-bjorn.andersson@linaro.orgSigned-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>

drivers/gpu/drm/msm/dp/dp_parser.c

@@ -50,18 +50,45 @@ static int dp_parser_ctrl_res(struct dp_parser *parser)
 	if (IS_ERR(dss->ahb.base))
 		return PTR_ERR(dss->ahb.base);
 
-	if (dss->ahb.len < DP_DEFAULT_P0_OFFSET + DP_DEFAULT_P0_SIZE) {
-		DRM_ERROR("legacy memory region not large enough\n");
-		return -EINVAL;
-	}
+	dss->aux.base = dp_ioremap(pdev, 1, &dss->aux.len);
+	if (IS_ERR(dss->aux.base)) {
+		/*
+		 * The initial binding had a single reg, but in order to
+		 * support variation in the sub-region sizes this was split.
+		 * dp_ioremap() will fail with -EINVAL here if only a single
+		 * reg is specified, so fill in the sub-region offsets and
+		 * lengths based on this single region.
+		 */
+		if (PTR_ERR(dss->aux.base) == -EINVAL) {
+			if (dss->ahb.len < DP_DEFAULT_P0_OFFSET + DP_DEFAULT_P0_SIZE) {
+				DRM_ERROR("legacy memory region not large enough\n");
+				return -EINVAL;
+			}
+
+			dss->ahb.len = DP_DEFAULT_AHB_SIZE;
+			dss->aux.base = dss->ahb.base + DP_DEFAULT_AUX_OFFSET;
+			dss->aux.len = DP_DEFAULT_AUX_SIZE;
+			dss->link.base = dss->ahb.base + DP_DEFAULT_LINK_OFFSET;
+			dss->link.len = DP_DEFAULT_LINK_SIZE;
+			dss->p0.base = dss->ahb.base + DP_DEFAULT_P0_OFFSET;
+			dss->p0.len = DP_DEFAULT_P0_SIZE;
+		} else {
+			DRM_ERROR("unable to remap aux region: %pe\n", dss->aux.base);
+			return PTR_ERR(dss->aux.base);
+		}
+	} else {
+		dss->link.base = dp_ioremap(pdev, 2, &dss->link.len);
+		if (IS_ERR(dss->link.base)) {
+			DRM_ERROR("unable to remap link region: %pe\n", dss->link.base);
+			return PTR_ERR(dss->link.base);
+		}
 
-	dss->ahb.len = DP_DEFAULT_AHB_SIZE;
-	dss->aux.base = dss->ahb.base + DP_DEFAULT_AUX_OFFSET;
-	dss->aux.len = DP_DEFAULT_AUX_SIZE;
-	dss->link.base = dss->ahb.base + DP_DEFAULT_LINK_OFFSET;
-	dss->link.len = DP_DEFAULT_LINK_SIZE;
-	dss->p0.base = dss->ahb.base + DP_DEFAULT_P0_OFFSET;
-	dss->p0.len = DP_DEFAULT_P0_SIZE;
+		dss->p0.base = dp_ioremap(pdev, 3, &dss->p0.len);
+		if (IS_ERR(dss->p0.base)) {
+			DRM_ERROR("unable to remap p0 region: %pe\n", dss->p0.base);
+			return PTR_ERR(dss->p0.base);
+		}
+	}
 
 	io->phy = devm_phy_get(&pdev->dev, "dp");
 	if (IS_ERR(io->phy))