[PATCH v3 3/5] drm: rcar-du: dsi: Improve DSI shutdown

[Tomi Valkeinen]

From: Tomi Valkeinen <tomi.valkeinen+renesas at ideasonboard.com>

Improve the DSI shutdown procedure by clearing various bits that were
set while enabling the DSI output. There has been no clear issues caused
by these, but it's safer to ensure that the features are disabled at the
start of the next DSI enable.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen+renesas at ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
---
 drivers/gpu/drm/rcar-du/rcar_mipi_dsi.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/gpu/drm/rcar-du/rcar_mipi_dsi.c b/drivers/gpu/drm/rcar-du/rcar_mipi_dsi.c
index 7f2be490fcf8..9c79fe2fc70b 100644
--- a/drivers/gpu/drm/rcar-du/rcar_mipi_dsi.c
+++ b/drivers/gpu/drm/rcar-du/rcar_mipi_dsi.c
@@ -441,9 +441,21 @@ static int rcar_mipi_dsi_startup(struct rcar_mipi_dsi *dsi,
 
 static void rcar_mipi_dsi_shutdown(struct rcar_mipi_dsi *dsi)
 {
+	/* Disable VCLKEN */
+	rcar_mipi_dsi_write(dsi, VCLKSET, 0);
+
+	/* Disable DOT clock */
+	rcar_mipi_dsi_write(dsi, VCLKSET, 0);
+
 	rcar_mipi_dsi_clr(dsi, PHYSETUP, PHYSETUP_RSTZ);
 	rcar_mipi_dsi_clr(dsi, PHYSETUP, PHYSETUP_SHUTDOWNZ);
 
+	/* CFGCLK disable */
+	rcar_mipi_dsi_clr(dsi, CFGCLKSET, CFGCLKSET_CKEN);
+
+	/* LPCLK disable */
+	rcar_mipi_dsi_clr(dsi, LPCLKSET, LPCLKSET_CKEN);
+
 	dev_dbg(dsi->dev, "DSI device is shutdown\n");
 }
 
-- 
2.34.1