OMAP: DSS2: DISPC: Fix minimum PCD value
The current driver had a hardcoded minimum value of 2 for pixel clock
divisor (PCD). This doesn't seem to be right.
OMAP4 TRM says that PCD can be 1 when not downscaling, and inverted
pixel clock (IPC) is off.
OMAP3 TRM says the same, but also in the register descriptions that PCD
value 1 is invalid.
OMAP2 TRM says PCD 2 is the minimum.
OMAP2 is still untested, but for both OMAP3 and OMAP4 PCD of 1 seems to
work fine.
This patch adds a new DSS feature, FEAT_PARAM_DSS_PCD, which is used to
find the minimum and maximum PCD. The minimum is set to 2 for OMAP2, and
1 for OMAP3/4.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
diff --git a/drivers/video/omap2/dss/dss_features.c b/drivers/video/omap2/dss/dss_features.c
index 8670612..076f399 100644
--- a/drivers/video/omap2/dss/dss_features.c
+++ b/drivers/video/omap2/dss/dss_features.c
@@ -281,6 +281,7 @@
static const struct dss_param_range omap2_dss_param_range[] = {
[FEAT_PARAM_DSS_FCK] = { 0, 173000000 },
+ [FEAT_PARAM_DSS_PCD] = { 2, 255 },
[FEAT_PARAM_DSIPLL_REGN] = { 0, 0 },
[FEAT_PARAM_DSIPLL_REGM] = { 0, 0 },
[FEAT_PARAM_DSIPLL_REGM_DISPC] = { 0, 0 },
@@ -291,6 +292,7 @@
static const struct dss_param_range omap3_dss_param_range[] = {
[FEAT_PARAM_DSS_FCK] = { 0, 173000000 },
+ [FEAT_PARAM_DSS_PCD] = { 1, 255 },
[FEAT_PARAM_DSIPLL_REGN] = { 0, (1 << 7) - 1 },
[FEAT_PARAM_DSIPLL_REGM] = { 0, (1 << 11) - 1 },
[FEAT_PARAM_DSIPLL_REGM_DISPC] = { 0, (1 << 4) - 1 },
@@ -301,6 +303,7 @@
static const struct dss_param_range omap4_dss_param_range[] = {
[FEAT_PARAM_DSS_FCK] = { 0, 186000000 },
+ [FEAT_PARAM_DSS_PCD] = { 1, 255 },
[FEAT_PARAM_DSIPLL_REGN] = { 0, (1 << 8) - 1 },
[FEAT_PARAM_DSIPLL_REGM] = { 0, (1 << 12) - 1 },
[FEAT_PARAM_DSIPLL_REGM_DISPC] = { 0, (1 << 5) - 1 },