OMAP: Introduce device specific set rate and get rate in omap_device structure

This patch extends the omap_device structure to contain pointers to scale the
operating rate of the device and to retrieve the operating rate of the device.
This patch also adds the three new APIs in the omap device layer
namely omap_device_set_rate that can be called to set a new operating
rate for a device, omap_device_get_rate that can be called to retrieve
the operating frequency for a device and omap_device_register_dvfs_callbacks
to register the device specific set_rate and get_rate functions.
The omap_device_set_rate and omap_device_get_rate does some routine error
checks and finally calls into the device specific set_rate
and get_rate APIs populated through omap_device_populate_rate_fns.

Signed-off-by: Thara Gopinath <thara@ti.com>
Signed-off-by: Vishwanath BS <vishwanath.bs@ti.com>

2 files changed, 58 insertions, 0 deletions

diff --git a/arch/arm/plat-omap/include/plat/omap_device.h b/arch/arm/plat-omap/include/plat/omap_device.h
index e4c349ff9fd..204fb0a9b2f 100644
--- a/arch/arm/plat-omap/include/plat/omap_device.h
+++ b/arch/arm/plat-omap/include/plat/omap_device.h
@@ -50,6 +50,8 @@ extern struct device omap_device_parent;
  * @hwmods: (one .. many per omap_device)
  * @hwmods_cnt: ARRAY_SIZE() of @hwmods
  * @pm_lats: ptr to an omap_device_pm_latency table
+ * @set_rate: fn ptr to change the operating rate.
+ * @get_rate: fn ptr to retrieve the current operating rate.
  * @pm_lats_cnt: ARRAY_SIZE() of what is passed to @pm_lats
  * @pm_lat_level: array index of the last odpl entry executed - -1 if never
  * @dev_wakeup_lat: dev wakeup latency in nanoseconds
@@ -73,6 +75,8 @@ struct omap_device {
 	s8				pm_lat_level;
 	u8				hwmods_cnt;
 	u8				_state;
+	int (*set_rate)(struct device *dev, unsigned long rate);
+	unsigned long (*get_rate) (struct device *dev);
 };
 
 /* Device driver interface (call via platform_data fn ptrs) */
@@ -107,6 +111,11 @@ 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_set_rate(struct device *dev, unsigned long freq);
+unsigned long omap_device_get_rate(struct device *dev);
+void omap_device_register_dvfs_callbacks(struct device *dev,
+		int (*set_rate)(struct device *dev, unsigned long rate),
+		unsigned long (*get_rate) (struct device *dev));
 u32 omap_device_get_context_loss_count(struct platform_device *pdev);
 
 /* Other */
diff --git a/arch/arm/plat-omap/omap_device.c b/arch/arm/plat-omap/omap_device.c
index a84e8494d76..4cee430c40d 100644
--- a/arch/arm/plat-omap/omap_device.c
+++ b/arch/arm/plat-omap/omap_device.c
@@ -810,6 +810,55 @@ int omap_device_enable_clocks(struct omap_device *od)
 	return 0;
 }
 
+int omap_device_set_rate(struct device *dev, unsigned long freq)
+{
+	struct platform_device *pdev;
+	struct omap_device *od;
+
+	pdev = container_of(dev, struct platform_device, dev);
+	od = _find_by_pdev(pdev);
+
+	if (!od->set_rate) {
+		dev_err(dev, "%s: No set_rate API for scaling device\n",
+			__func__);
+		return -ENODATA;
+	}
+
+	return od->set_rate(dev, freq);
+}
+
+unsigned long omap_device_get_rate(struct device *dev)
+{
+	struct platform_device *pdev;
+	struct omap_device *od;
+
+	pdev = container_of(dev, struct platform_device, dev);
+	od = _find_by_pdev(pdev);
+
+
+	if (!od->get_rate) {
+		dev_err(dev, "%s: No get rate API for the device\n",
+			__func__);
+		return 0;
+	}
+
+	return od->get_rate(dev);
+}
+
+void omap_device_register_dvfs_callbacks(struct device *dev,
+		int (*set_rate)(struct device *dev, unsigned long rate),
+		unsigned long (*get_rate) (struct device *dev))
+{
+	struct platform_device *pdev;
+	struct omap_device *od;
+
+	pdev = container_of(dev, struct platform_device, dev);
+	od = _find_by_pdev(pdev);
+
+	od->set_rate = set_rate;
+	od->get_rate = get_rate;
+}
+
 struct device omap_device_parent = {
 	.init_name	= "omap",
 	.parent         = &platform_bus,