[PATCH v1 5/6] drm/mediatek: mtk_dpi: Add checks for reg_h_fre_con existence

[AngeloGioacchino Del Regno]

In preparation for adding support for newer DPI instances which
do support direct-pin but do not have any H_FRE_CON register,
like the one found in MT8195 and MT8188, add a branch to check
if the reg_h_fre_con variable was declared in the mtk_dpi_conf
structure for the probed SoC DPI version.

As a note, this is useful specifically only for cases in which
the support_direct_pin variable is true, so mt8195-dpintf is
not affected by any issue.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno at collabora.com>
---
 drivers/gpu/drm/mediatek/mtk_dpi.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c b/drivers/gpu/drm/mediatek/mtk_dpi.c
index 378b49b6bdfb..79923d1bfbc9 100644
--- a/drivers/gpu/drm/mediatek/mtk_dpi.c
+++ b/drivers/gpu/drm/mediatek/mtk_dpi.c
@@ -430,12 +430,13 @@ static void mtk_dpi_config_swap_input(struct mtk_dpi *dpi, bool enable)
 
 static void mtk_dpi_config_2n_h_fre(struct mtk_dpi *dpi)
 {
-	mtk_dpi_mask(dpi, dpi->conf->reg_h_fre_con, H_FRE_2N, H_FRE_2N);
+	if (dpi->conf->reg_h_fre_con)
+		mtk_dpi_mask(dpi, dpi->conf->reg_h_fre_con, H_FRE_2N, H_FRE_2N);
 }
 
 static void mtk_dpi_config_disable_edge(struct mtk_dpi *dpi)
 {
-	if (dpi->conf->edge_sel_en)
+	if (dpi->conf->edge_sel_en && dpi->conf->reg_h_fre_con)
 		mtk_dpi_mask(dpi, dpi->conf->reg_h_fre_con, 0, EDGE_SEL_EN);
 }
 
-- 
2.47.0