drm/msm/dp: use ARRAY_SIZE for calculating num_descs

If for some reason the msm_dp_config::descs array starts from non-zero
index or contains the hole, setting the msm_dp_config::num_descs might
be not that obvious and error-prone. Use ARRAY_SIZE to set this field
rather than encoding the value manually.
Reported-by: Kuogee Hsieh <quic_khsieh@quicinc.com>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Kuogee Hsieh <quic_khsieh@quicinc.com>
Patchwork: https://patchwork.freedesktop.org/patch/491399/
Link: https://lore.kernel.org/r/20220627165413.657142-1-dmitry.baryshkov@linaro.orgSigned-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

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

@@ -131,35 +131,43 @@ struct msm_dp_config {
 	size_t num_descs;
 };
 
+static const struct msm_dp_desc sc7180_dp_descs[] = {
+	[MSM_DP_CONTROLLER_0] = { .io_start = 0x0ae90000, .connector_type = DRM_MODE_CONNECTOR_DisplayPort },
+};
+
 static const struct msm_dp_config sc7180_dp_cfg = {
-	.descs = (const struct msm_dp_desc[]) {
-		[MSM_DP_CONTROLLER_0] = { .io_start = 0x0ae90000, .connector_type = DRM_MODE_CONNECTOR_DisplayPort },
-	},
-	.num_descs = 1,
+	.descs = sc7180_dp_descs,
+	.num_descs = ARRAY_SIZE(sc7180_dp_descs),
+};
+
+static const struct msm_dp_desc sc7280_dp_descs[] = {
+	[MSM_DP_CONTROLLER_0] =	{ .io_start = 0x0ae90000, .connector_type = DRM_MODE_CONNECTOR_DisplayPort, .wide_bus_en = true },
+	[MSM_DP_CONTROLLER_1] =	{ .io_start = 0x0aea0000, .connector_type = DRM_MODE_CONNECTOR_eDP, .wide_bus_en = true },
 };
 
 static const struct msm_dp_config sc7280_dp_cfg = {
-	.descs = (const struct msm_dp_desc[]) {
-		[MSM_DP_CONTROLLER_0] =	{ .io_start = 0x0ae90000, .connector_type = DRM_MODE_CONNECTOR_DisplayPort, .wide_bus_en = true },
-		[MSM_DP_CONTROLLER_1] =	{ .io_start = 0x0aea0000, .connector_type = DRM_MODE_CONNECTOR_eDP, .wide_bus_en = true },
-	},
-	.num_descs = 2,
+	.descs = sc7280_dp_descs,
+	.num_descs = ARRAY_SIZE(sc7280_dp_descs),
+};
+
+static const struct msm_dp_desc sc8180x_dp_descs[] = {
+	[MSM_DP_CONTROLLER_0] = { .io_start = 0x0ae90000, .connector_type = DRM_MODE_CONNECTOR_DisplayPort },
+	[MSM_DP_CONTROLLER_1] = { .io_start = 0x0ae98000, .connector_type = DRM_MODE_CONNECTOR_DisplayPort },
+	[MSM_DP_CONTROLLER_2] = { .io_start = 0x0ae9a000, .connector_type = DRM_MODE_CONNECTOR_eDP },
 };
 
 static const struct msm_dp_config sc8180x_dp_cfg = {
-	.descs = (const struct msm_dp_desc[]) {
-		[MSM_DP_CONTROLLER_0] = { .io_start = 0x0ae90000, .connector_type = DRM_MODE_CONNECTOR_DisplayPort },
-		[MSM_DP_CONTROLLER_1] = { .io_start = 0x0ae98000, .connector_type = DRM_MODE_CONNECTOR_DisplayPort },
-		[MSM_DP_CONTROLLER_2] = { .io_start = 0x0ae9a000, .connector_type = DRM_MODE_CONNECTOR_eDP },
-	},
-	.num_descs = 3,
+	.descs = sc8180x_dp_descs,
+	.num_descs = ARRAY_SIZE(sc8180x_dp_descs),
+};
+
+static const struct msm_dp_desc sm8350_dp_descs[] = {
+	[MSM_DP_CONTROLLER_0] = { .io_start = 0x0ae90000, .connector_type = DRM_MODE_CONNECTOR_DisplayPort },
 };
 
 static const struct msm_dp_config sm8350_dp_cfg = {
-	.descs = (const struct msm_dp_desc[]) {
-		[MSM_DP_CONTROLLER_0] = { .io_start = 0x0ae90000, .connector_type = DRM_MODE_CONNECTOR_DisplayPort },
-	},
-	.num_descs = 1,
+	.descs = sm8350_dp_descs,
+	.num_descs = ARRAY_SIZE(sm8350_dp_descs),
 };
 
 static const struct of_device_id dp_dt_match[] = {