drm: renesas: rz-du: mipi_dsi: Make "rst" reset control optional for RZ/V2H(P)

In preparation for adding support for the Renesas RZ/V2H(P) SoC, make the
"rst" reset control optional in the MIPI DSI driver. The RZ/V2H(P) SoC
does not provide this reset line, and attempting to acquire it using the
mandatory API causes probe failure.

Switching to devm_reset_control_get_optional_exclusive() ensures
compatibility with both SoCs that provide this reset line and those that
do not, such as RZ/V2H(P).

Co-developed-by: Fabrizio Castro <fabrizio.castro.jz@renesas.com>
Signed-off-by: Fabrizio Castro <fabrizio.castro.jz@renesas.com>
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Link: https://lore.kernel.org/r/20250609225630.502888-6-prabhakar.mahadev-lad.rj@bp.renesas.com

diff --git a/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c b/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c
index 85074e0c3cc4c3aa20dc898a150a266e7fc17449..d4f2867e0c5f9b4cf7d504d9527902fc76158c48 100644 (file)
--- a/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c
+++ b/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c
@@ -937,7 +937,7 @@ static int rzg2l_mipi_dsi_probe(struct platform_device *pdev)
        if (IS_ERR(dsi->vclk))
                return PTR_ERR(dsi->vclk);
 
-       dsi->rstc = devm_reset_control_get_exclusive(dsi->dev, "rst");
+       dsi->rstc = devm_reset_control_get_optional_exclusive(dsi->dev, "rst");
        if (IS_ERR(dsi->rstc))
                return dev_err_probe(dsi->dev, PTR_ERR(dsi->rstc),
                                     "failed to get rst\n");