ARM: OMAP2PLUS: DSS: Ensure DSS works correctly if display is enabled in bootloader

Resetting DISPC when a DISPC output is enabled causes the DSS to go into an
inconsistent state. Thus if the bootloader has enabled a display, the hwmod code
cannot reset the DISPC module just like that, but the outputs need to be
disabled first.

Add function dispc_disable_outputs() which disables all active overlay manager
and ensure all frame transfers are completed.

Modify omap_dss_reset() to call this function and clear DSS_CONTROL,
DSS_SDI_CONTROL and DSS_PLL_CONTROL so that DSS is in a clean state when the
DSS2 driver starts.

This resolves the hang issue(caused by a L3 error during boot) seen on the
beagle board C3, which has a factory bootloader that enables display. The issue
is resolved with this patch.

Thanks to Tomi and Sricharan for some additional testing.

Acked-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Tested-by: R, Sricharan <r.sricharan@ti.com>
Signed-off-by: Archit Taneja <archit@ti.com>
[paul@pwsan.com: restructured code, removed omap_{read,write}l(), removed
 cpu_is_omap*() calls and converted to dev_attr]
Signed-off-by: Paul Walmsley <paul@pwsan.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/arch/arm/mach-omap2/omap_hwmod_44xx_data.c b/arch/arm/mach-omap2/omap_hwmod_44xx_data.c
index 3b04d63316f5..daaf165af696 100644
--- a/arch/arm/mach-omap2/omap_hwmod_44xx_data.c
+++ b/arch/arm/mach-omap2/omap_hwmod_44xx_data.c
@@ -1327,6 +1327,11 @@ static struct omap_hwmod_addr_space omap44xx_dss_dispc_addrs[] = {
 	{ }
 };
 
+static struct omap_dss_dispc_dev_attr omap44xx_dss_dispc_dev_attr = {
+	.manager_count		= 3,
+	.has_framedonetv_irq	= 1
+};
+
 /* l4_per -> dss_dispc */
 static struct omap_hwmod_ocp_if omap44xx_l4_per__dss_dispc = {
 	.master		= &omap44xx_l4_per_hwmod,
@@ -1357,6 +1362,7 @@ static struct omap_hwmod omap44xx_dss_dispc_hwmod = {
 	},
 	.slaves		= omap44xx_dss_dispc_slaves,
 	.slaves_cnt	= ARRAY_SIZE(omap44xx_dss_dispc_slaves),
+	.dev_attr	= &omap44xx_dss_dispc_dev_attr
 };
 
 /*