On 18/01/2023 23:12, Laurent Pinchart wrote:
Hi Tomi,
Thank you for the patch.
On Tue, Jan 17, 2023 at 03:51:51PM +0200, Tomi Valkeinen wrote:
From: Koji Matsuoka <koji.matsuoka.xm@xxxxxxxxxxx>
According to H/W manual, LVDCR0 register must be cleared bit by bit when
s@H/W@the hardware/
disabling LVDS.
I don't like this much, but I think I'll stop fighting :-)
Signed-off-by: Koji Matsuoka <koji.matsuoka.xm@xxxxxxxxxxx>
Signed-off-by: LUU HOAI <hoai.luu.ub@xxxxxxxxxxx>
[tomi.valkeinen: simplified the code a bit]
Signed-off-by: Tomi Valkeinen <tomi.valkeinen+renesas@xxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/rcar-du/rcar_lvds.c | 27 ++++++++++++++++++++++++++-
1 file changed, 26 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/rcar-du/rcar_lvds.c b/drivers/gpu/drm/rcar-du/rcar_lvds.c
index 674b727cdaa2..01800cef1c33 100644
--- a/drivers/gpu/drm/rcar-du/rcar_lvds.c
+++ b/drivers/gpu/drm/rcar-du/rcar_lvds.c
@@ -87,6 +87,11 @@ static void rcar_lvds_write(struct rcar_lvds *lvds, u32 reg, u32 data)
iowrite32(data, lvds->mmio + reg);
}
+static u32 rcar_lvds_read(struct rcar_lvds *lvds, u32 reg)
+{
+ return ioread32(lvds->mmio + reg);
+}
Could you please move read before write ?
Sure.
+
/* -----------------------------------------------------------------------------
* PLL Setup
*/
@@ -549,8 +554,28 @@ static void rcar_lvds_atomic_disable(struct drm_bridge *bridge,
struct drm_bridge_state *old_bridge_state)
{
struct rcar_lvds *lvds = bridge_to_rcar_lvds(bridge);
+ u32 lvdcr0;
+
+ lvdcr0 = rcar_lvds_read(lvds, LVDCR0);
+
+ lvdcr0 &= ~LVDCR0_LVRES;
+ rcar_lvds_write(lvds, LVDCR0, lvdcr0);
+
+ if (lvds->info->quirks & RCAR_LVDS_QUIRK_GEN3_LVEN) {
+ lvdcr0 &= ~LVDCR0_LVEN;
+ rcar_lvds_write(lvds, LVDCR0, lvdcr0);
+ }
+
+ if (lvds->info->quirks & RCAR_LVDS_QUIRK_PWD) {
+ lvdcr0 &= ~LVDCR0_PWD;
+ rcar_lvds_write(lvds, LVDCR0, lvdcr0);
+ }
+
+ if (!(lvds->info->quirks & RCAR_LVDS_QUIRK_EXT_PLL)) {
+ lvdcr0 &= ~LVDCR0_PLLON;
+ rcar_lvds_write(lvds, LVDCR0, lvdcr0);
+ }
This will leave LVDCR0_BEN and LVDCR0_LVEN on Gen2. Is that fine ?
I don't know, I don't have the manuals or HW. But your point is a bit
worrying.
I think we can just do a rcar_lvds_write(lvds, LVDCR0, 0) after the
above shenanigans, to make sure everything is disabled. The HW manual
doesn't tell us to do that, though, on gen3. Do you think that will be a
problem?
And I'm not fully serious with the last sentence...
Tomi
