video: tegra: host: use runtime pm for clock management

- use runtime pm for clock management of host1x
and its clients thus replacing ACM
- start a delayed worker after disabling the clock
if module supports power gating
- in its timeout handler power gate the module after saving
its context for next submit
- use auto-suspend mode of runtime pm for clock management
- pm core seems to keep a ref count on runtime pm thus
we cannot use runtime pm's usage_count as an idicator
of module idle during suspend
- do not use runtime pm call-backs during system suspend.
instead manage the clocks directly for context save of
modules that support it
- enable runtime pm only during boot-up as pm core disables
it before suspending the device and enables it after resume

for bug 887332

Change-Id: I3b30643e8e75c13684cf4edaaae4429c3a18d6eb
Signed-off-by: Mayuresh Kulkarni <mkulkarni@nvidia.com>
Reviewed-on: http://git-master/r/79186
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>

1 files changed, 21 insertions, 4 deletions

diff --git a/drivers/video/tegra/host/bus.c b/drivers/video/tegra/host/bus.c
index 8234d0fa64c3..8fd4aa830afe 100644
--- a/drivers/video/tegra/host/bus.c
+++ b/drivers/video/tegra/host/bus.c
@@ -19,7 +19,7 @@
 
 #include <linux/pm_runtime.h>
 #include <linux/nvhost.h>
-
+#include <mach/clk.h>
 #include "dev.h"
 
 struct nvhost_master *nvhost;
@@ -487,17 +487,34 @@ static int nvhost_pm_restore_noirq(struct device *dev)
 
 int __weak nvhost_pm_runtime_suspend(struct device *dev)
 {
-	return pm_generic_runtime_suspend(dev);
+	int i;
+	struct nvhost_device *device = to_nvhost_device(dev);
+
+	for (i = 0; i < device->num_clks; i++)
+		clk_disable(device->clk[i]);
+
+	if (device->can_powergate)
+		schedule_delayed_work(&device->powerstate_down,
+			msecs_to_jiffies(device->powergate_delay));
+
+	return 0;
 };
 
 int __weak nvhost_pm_runtime_resume(struct device *dev)
 {
-	return pm_generic_runtime_resume(dev);
+	int i;
+	struct nvhost_device *device = to_nvhost_device(dev);
+
+	for (i = 0; i < device->num_clks; i++)
+		clk_enable(device->clk[i]);
+
+	return 0;
 };
 
 int __weak nvhost_pm_runtime_idle(struct device *dev)
 {
-	return pm_generic_runtime_idle(dev);
+	pm_runtime_autosuspend(dev);
+	return 0;
 };
 
 #else /* !CONFIG_PM_RUNTIME */