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authorTomi Valkeinen <tomi.valkeinen@ti.com>2012-03-08 12:52:38 +0200
committerTomi Valkeinen <tomi.valkeinen@ti.com>2012-04-23 10:48:03 +0300
commita8081d317978416197295df22fc2ea71e4812f50 (patch)
treec4156f1a48fd63f6abc6209cc98d80523e36a843
parent62c1dcfc7451a8e42104776705a317e06a8e24a3 (diff)
OMAPDSS: Ensure OPP100 when DSS is operational
Most of the DSS clocks have restrictions on their frequency based on the OPP in use. For example, maximum frequency for a clock may be 180MHz in OPP100, but 90MHz in OPP50. This means that when a high enough pixel clock or function clock is required, we need to use OPP100. However, there's currently no way in the PM framework to make that kind of request. The closest we get is to ask for very high bus throughput from the PM framework, which should effectively force OPP100. This patch is a simple version for handling the problem. Instead of asking for OPP100 only when needed, this patch asks for OPP100 whenever DSS is active. This obviously is not an optimal solution for cases with small displays where OPP50 would work just fine. However, a proper solution is a complex one, and this patch is a short term solution for the problem. Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com> Cc: Paul Walmsley <paul@pwsan.com> Acked-by: Kevin Hilman <khilman@ti.com>
-rw-r--r--drivers/video/omap2/dss/core.c10
-rw-r--r--drivers/video/omap2/dss/dss.c13
-rw-r--r--drivers/video/omap2/dss/dss.h1
3 files changed, 24 insertions, 0 deletions
diff --git a/drivers/video/omap2/dss/core.c b/drivers/video/omap2/dss/core.c
index e8a120771ac..5ad8cc79823 100644
--- a/drivers/video/omap2/dss/core.c
+++ b/drivers/video/omap2/dss/core.c
@@ -87,6 +87,16 @@ struct regulator *dss_get_vdds_sdi(void)
return reg;
}
+int dss_set_min_bus_tput(struct device *dev, unsigned long tput)
+{
+ struct omap_dss_board_info *pdata = core.pdev->dev.platform_data;
+
+ if (pdata->set_min_bus_tput)
+ return pdata->set_min_bus_tput(dev, tput);
+ else
+ return 0;
+}
+
#if defined(CONFIG_DEBUG_FS) && defined(CONFIG_OMAP2_DSS_DEBUG_SUPPORT)
static int dss_debug_show(struct seq_file *s, void *unused)
{
diff --git a/drivers/video/omap2/dss/dss.c b/drivers/video/omap2/dss/dss.c
index bd2d5e15946..e731aa46eea 100644
--- a/drivers/video/omap2/dss/dss.c
+++ b/drivers/video/omap2/dss/dss.c
@@ -829,11 +829,24 @@ static int omap_dsshw_remove(struct platform_device *pdev)
static int dss_runtime_suspend(struct device *dev)
{
dss_save_context();
+ dss_set_min_bus_tput(dev, 0);
return 0;
}
static int dss_runtime_resume(struct device *dev)
{
+ int r;
+ /*
+ * Set an arbitrarily high tput request to ensure OPP100.
+ * What we should really do is to make a request to stay in OPP100,
+ * without any tput requirements, but that is not currently possible
+ * via the PM layer.
+ */
+
+ r = dss_set_min_bus_tput(dev, 1000000000);
+ if (r)
+ return r;
+
dss_restore_context();
return 0;
}
diff --git a/drivers/video/omap2/dss/dss.h b/drivers/video/omap2/dss/dss.h
index d4b3dff2ead..42f8f62cf3d 100644
--- a/drivers/video/omap2/dss/dss.h
+++ b/drivers/video/omap2/dss/dss.h
@@ -162,6 +162,7 @@ struct platform_device;
struct bus_type *dss_get_bus(void);
struct regulator *dss_get_vdds_dsi(void);
struct regulator *dss_get_vdds_sdi(void);
+int dss_set_min_bus_tput(struct device *dev, unsigned long tput);
/* apply */
void dss_apply_init(void);