This patch adds omap_device_scale API which can be used to generic
device rate scaling.
Signed-off-by: Thara Gopinath <thara@xxxxxx>
---
arch/arm/plat-omap/include/plat/omap_device.h | 3 +-
arch/arm/plat-omap/omap_device.c | 78 +++++++++++++++++++++++++
2 files changed, 80 insertions(+), 1 deletions(-)
diff --git a/arch/arm/plat-omap/include/plat/omap_device.h b/arch/arm/plat-omap/include/plat/omap_device.h
index 2a37345..daafb5a 100644
--- a/arch/arm/plat-omap/include/plat/omap_device.h
+++ b/arch/arm/plat-omap/include/plat/omap_device.h
@@ -116,6 +116,8 @@ unsigned long omap_device_get_rate(struct device *dev);
void omap_device_populate_rate_fns(struct device *dev,
int (*set_rate)(struct device *dev, unsigned long rate),
unsigned long (*get_rate) (struct device *dev));
+int omap_device_scale(struct device *req_dev, struct device *dev,
+ unsigned long rate);
/* Other */
@@ -125,7 +127,6 @@ int omap_device_enable_hwmods(struct omap_device *od);
int omap_device_disable_clocks(struct omap_device *od);
int omap_device_enable_clocks(struct omap_device *od);
-
/*
* Entries should be kept in latency order ascending
*
diff --git a/arch/arm/plat-omap/omap_device.c b/arch/arm/plat-omap/omap_device.c
index ffe06eb..a273230 100644
--- a/arch/arm/plat-omap/omap_device.c
+++ b/arch/arm/plat-omap/omap_device.c
@@ -83,6 +83,7 @@
#include <linux/err.h>
#include <linux/io.h>
#include <linux/clk.h>
+#include <linux/opp.h>
#include <plat/omap_device.h>
#include <plat/omap_hwmod.h>
@@ -834,6 +835,83 @@ void omap_device_populate_rate_fns(struct device *dev,
od->get_rate = get_rate;
}
+/**
+ * omap_device_scale() - Set a new rate at which the device is to operate
+ * @req_dev: pointer to the device requesting the scaling.
+ * @dev: pointer to the device that is to be scaled
+ * @rate: the rnew rate for the device.
+ *
+ * This API gets the device opp table associated with this device and
+ * tries putting the device to the requested rate and the voltage domain
+ * associated with the device to the voltage corresponding to the
+ * requested rate. Since multiple devices can be assocciated with a
+ * voltage domain this API finds out the possible voltage the
+ * voltage domain can enter and then decides on the final device
+ * rate. Return 0 on success else the error value
+ */
+int omap_device_scale(struct device *req_dev, struct device *dev,
+ unsigned long rate)
+{
+ struct opp *opp;
+ unsigned long volt, freq, min_freq, max_freq;
+ struct voltagedomain *voltdm;
+ struct platform_device *pdev;
+ struct omap_device *od;
+ int ret;
+
+ pdev = container_of(dev, struct platform_device, dev);
+ od = _find_by_pdev(pdev);
+
+ /*
+ * Figure out if the desired frquency lies between the
+ * maximum and minimum possible for the particular device
+ */
+ min_freq = 0;
+ if (IS_ERR(opp_find_freq_ceil(dev, &min_freq))) {
+ dev_err(dev, "%s: Unable to find lowest opp\n", __func__);
+ return -ENODEV;
+ }
+
+ max_freq = ULONG_MAX;
+ if (IS_ERR(opp_find_freq_floor(dev, &max_freq))) {
+ dev_err(dev, "%s: Unable to find highest opp\n", __func__);
+ return -ENODEV;
+ }
+
+ if (rate < min_freq)
+ freq = min_freq;
+ else if (rate > max_freq)
+ freq = max_freq;
+ else
+ freq = rate;
+
+ opp = opp_find_freq_ceil(dev, &freq);
+ if (IS_ERR(opp)) {
+ dev_err(dev, "%s: Unable to find OPP for freq%ld\n",
+ __func__, rate);
+ return -ENODEV;
+ }
+
+ /* Get the voltage corresponding to the requested frequency */
+ volt = opp_get_voltage(opp);
+
+ /*
+ * Call into the voltage layer to get the final voltage possible
+ * for the voltage domain associated with the device.
+ */
+ voltdm = od->hwmods[0]->voltdm;
+ ret = omap_voltage_add_request(voltdm, req_dev, &volt);
+ if (ret) {
+ dev_err(dev, "%s: Unable to get the final volt for scaling\n",
+ __func__);
+ return ret;
+ }
+
+ /* Do the actual scaling */
+ return omap_voltage_scale(voltdm, volt);
+}
+EXPORT_SYMBOL(omap_device_scale);
+
struct device omap_device_parent = {
.init_name = "omap",
.parent = &platform_bus,
--
1.7.0.4
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