According to revision 1.00 of R-Car Gen3 Soc manual, writing to ESCR
register of DU channels equipped with a display PLL (DPLL) is invalid.
Fix this by writing ESCR only for channels making use of the DU internal
post-divider to generate the dotclockout signal, with R-Car H3 ES1.x being
a notable exception.
Signed-off-by: Jacopo Mondi <jacopo+renesas@xxxxxxxxxx>
---
drivers/gpu/drm/rcar-du/rcar_du_crtc.c | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/rcar-du/rcar_du_crtc.c b/drivers/gpu/drm/rcar-du/rcar_du_crtc.c
index 1541152..7b1c05b 100644
--- a/drivers/gpu/drm/rcar-du/rcar_du_crtc.c
+++ b/drivers/gpu/drm/rcar-du/rcar_du_crtc.c
@@ -246,7 +246,6 @@ static void rcar_du_crtc_set_display_timing(struct rcar_du_crtc *rcrtc)
struct rcar_du_device *rcdu = rcrtc->group->dev;
unsigned long mode_clock = mode->clock * 1000;
u32 dsmr;
- u32 escr;
if (rcdu->info->dpll_mask & (1 << rcrtc->index)) {
unsigned long target = mode_clock;
@@ -293,7 +292,11 @@ static void rcar_du_crtc_set_display_timing(struct rcar_du_crtc *rcrtc)
rcar_du_group_write(rcrtc->group, DPLLCR, dpllcr);
- escr = ESCR_DCLKSEL_DCLKIN | div;
+ /* Only H3 ES1.x has a post divider when a DPLL is present. */
+ if (soc_device_match(rcar_du_r8a7795_es1))
+ rcar_du_crtc_write(rcrtc,
+ rcrtc->index % 2 ? ESCR13 : ESCR02,
+ ESCR_DCLKSEL_DCLKIN | div);
} else {
struct du_clk_params params = { .diff = (unsigned long)-1 };
@@ -308,12 +311,10 @@ static void rcar_du_crtc_set_display_timing(struct rcar_du_crtc *rcrtc)
params.rate);
clk_set_rate(params.clk, params.rate);
- escr = params.escr;
+ rcar_du_crtc_write(rcrtc, rcrtc->index % 2 ? ESCR13 : ESCR02,
+ params.escr);
}
- dev_dbg(rcrtc->group->dev->dev, "%s: ESCR 0x%08x\n", __func__, escr);
-
- rcar_du_crtc_write(rcrtc, rcrtc->index % 2 ? ESCR13 : ESCR02, escr);
rcar_du_crtc_write(rcrtc, rcrtc->index % 2 ? OTAR13 : OTAR02, 0);
/* Signal polarities */
--
2.7.4
