[PATCH/RFC 2/2] OMAP: PM: implement context loss count APIs

[Kevin Hilman <khilman@deeprootsystems.com>]

Implement OMAP PM layer omap_pm_get_dev_context_loss_count() API by
creating similar APIs at the omap_device and omap_hwmod levels.  The
omap_hwmod level call is the layer with access to the powerdomain
core, so it is the place where the powerdomain is queried to get the
context loss count.

NOTE: only works for devices which have been converted to use
      omap_device/omap_hwmod.

Longer term, we could possibly remove this API from the OMAP PM layer,
and instead directly use the omap_device level API.

Cc: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
---
 arch/arm/mach-omap2/omap_hwmod.c              |   18 ++++++++++++++++++
 arch/arm/plat-omap/include/plat/omap_device.h |    1 +
 arch/arm/plat-omap/include/plat/omap_hwmod.h  |    1 +
 arch/arm/plat-omap/omap-pm-noop.c             |   17 +++++++++--------
 arch/arm/plat-omap/omap_device.c              |   20 ++++++++++++++++++++
 5 files changed, 49 insertions(+), 8 deletions(-)

diff --git a/arch/arm/mach-omap2/omap_hwmod.c b/arch/arm/mach-omap2/omap_hwmod.c
index 81c1097..0ec9c70 100644
--- a/arch/arm/mach-omap2/omap_hwmod.c
+++ b/arch/arm/mach-omap2/omap_hwmod.c
@@ -2220,3 +2220,21 @@ ohsps_unlock:
 
 	return ret;
 }
+
+/**
+ * omap_hwmod_get_context_loss_count - get lost context count
+ * @oh: struct omap_hwmod *
+ *
+ * Query the powerdomain of of @oh to get the context loss
+ * count for this device.
+ */
+int omap_hwmod_get_context_loss_count(struct omap_hwmod *oh)
+{
+	struct powerdomain *pwrdm;
+
+	pwrdm = omap_hwmod_get_pwrdm(oh);
+	if (!pwrdm)
+		return -ENODEV;
+
+	return pwrdm_get_context_loss_count(pwrdm);
+}
diff --git a/arch/arm/plat-omap/include/plat/omap_device.h b/arch/arm/plat-omap/include/plat/omap_device.h
index 28e2d1a..70d31d0 100644
--- a/arch/arm/plat-omap/include/plat/omap_device.h
+++ b/arch/arm/plat-omap/include/plat/omap_device.h
@@ -107,6 +107,7 @@ void __iomem *omap_device_get_rt_va(struct omap_device *od);
 int omap_device_align_pm_lat(struct platform_device *pdev,
 			     u32 new_wakeup_lat_limit);
 struct powerdomain *omap_device_get_pwrdm(struct omap_device *od);
+int omap_device_get_context_loss_count(struct platform_device *pdev);
 
 /* Other */
 
diff --git a/arch/arm/plat-omap/include/plat/omap_hwmod.h b/arch/arm/plat-omap/include/plat/omap_hwmod.h
index 62bdb23..5a96ac5 100644
--- a/arch/arm/plat-omap/include/plat/omap_hwmod.h
+++ b/arch/arm/plat-omap/include/plat/omap_hwmod.h
@@ -568,6 +568,7 @@ int omap_hwmod_for_each_by_class(const char *classname,
 				 void *user);
 
 int omap_hwmod_set_postsetup_state(struct omap_hwmod *oh, u8 state);
+int omap_hwmod_get_context_loss_count(struct omap_hwmod *oh);
 
 /*
  * Chip variant-specific hwmod init routines - XXX should be converted
diff --git a/arch/arm/plat-omap/omap-pm-noop.c b/arch/arm/plat-omap/omap-pm-noop.c
index 7578366..5a58f97 100644
--- a/arch/arm/plat-omap/omap-pm-noop.c
+++ b/arch/arm/plat-omap/omap-pm-noop.c
@@ -20,9 +20,11 @@
 #include <linux/init.h>
 #include <linux/cpufreq.h>
 #include <linux/device.h>
+#include <linux/platform_device.h>
 
 /* Interface documentation is in mach/omap-pm.h */
 #include <plat/omap-pm.h>
+#include <plat/omap_device.h>
 
 struct omap_opp *dsp_opps;
 struct omap_opp *mpu_opps;
@@ -288,20 +290,19 @@ unsigned long omap_pm_cpu_get_freq(void)
 
 int omap_pm_get_dev_context_loss_count(struct device *dev)
 {
+	struct platform_device *pdev = to_platform_device(dev);
+	int count;
+
 	if (!dev) {
 		WARN_ON(1);
 		return -EINVAL;
 	};
 
-	pr_debug("OMAP PM: returning context loss count for dev %s\n",
-		 dev_name(dev));
+	count = omap_device_get_context_loss_count(pdev);
+	pr_debug("OMAP PM: context loss count for dev %s = %d\n",
+		 dev_name(dev), count);
 
-	/*
-	 * Map the device to the powerdomain.  Return the powerdomain
-	 * off counter.
-	 */
-
-	return 0;
+	return count;
 }
 
 
diff --git a/arch/arm/plat-omap/omap_device.c b/arch/arm/plat-omap/omap_device.c
index abe933c..e29c2d6 100644
--- a/arch/arm/plat-omap/omap_device.c
+++ b/arch/arm/plat-omap/omap_device.c
@@ -280,6 +280,26 @@ static void _add_optional_clock_alias(struct omap_device *od,
 /* Public functions for use by core code */
 
 /**
+ * omap_device_get_context_loss_count - get lost context count
+ * @od: struct omap_device *
+ *
+ * Using the primary hwmod for this device, query the context loss
+ * count for this device.
+ */
+int omap_device_get_context_loss_count(struct platform_device *pdev)
+{
+	struct omap_device *od;
+	int ret = -ENODEV;
+
+	od = _find_by_pdev(pdev);
+
+	if (od->hwmods_cnt)
+		omap_hwmod_get_context_loss_count(od->hwmods[0]);
+
+	return ret;
+}
+
+/**
  * omap_device_count_resources - count number of struct resource entries needed
  * @od: struct omap_device *
  *
-- 
1.7.2.1