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authorVishwanath BS <vishwanath.bs@ti.com>2011-01-12 21:20:03 +0530
committerNicolas Pitre <nicolas.pitre@linaro.org>2011-02-21 23:10:39 -0500
commitdef12feea28270116be43242e9f807107fd717b5 (patch)
tree68805562e50a96bbaf1612fae05aa3e2ae9a3957
parentd79ea126cc51b9d2b80141e92246128b9010133d (diff)
downloadlinux-linaro-def12feea28270116be43242e9f807107fd717b5.tar.gz
OMAP: Introduce device scale implementation
This patch adds omap_device_scale API which can be used to generic device rate scaling. Based on original patch from Thara. Signed-off-by: Vishwanath BS <vishwanath.bs@ti.com> Cc: Thara Gopinath <thara@ti.com>
-rw-r--r--arch/arm/mach-omap2/dvfs.c116
-rw-r--r--arch/arm/plat-omap/include/plat/dvfs.h7
2 files changed, 123 insertions, 0 deletions
diff --git a/arch/arm/mach-omap2/dvfs.c b/arch/arm/mach-omap2/dvfs.c
index c9d3894df69..05a9ce3767b 100644
--- a/arch/arm/mach-omap2/dvfs.c
+++ b/arch/arm/mach-omap2/dvfs.c
@@ -19,6 +19,7 @@
#include <plat/common.h>
#include <plat/voltage.h>
#include <plat/omap_device.h>
+#include <plat/smartreflex.h>
/**
* struct omap_dev_user_list - Structure maitain userlist per device
@@ -585,6 +586,121 @@ static int omap_dvfs_voltage_scale(struct omap_vdd_dvfs_info *dvfs_info)
}
/**
+ * omap_device_scale() - Set a new rate at which the device is to operate
+ * @req_dev: pointer to the device requesting the scaling.
+ * @target_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 *target_dev,
+ unsigned long rate)
+{
+ struct opp *opp;
+ unsigned long volt, freq, min_freq, max_freq;
+ struct omap_vdd_dvfs_info *dvfs_info;
+ struct platform_device *pdev;
+ struct omap_device *od;
+ int ret = 0;
+
+ pdev = container_of(target_dev, struct platform_device, dev);
+ od = container_of(pdev, struct omap_device, 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(target_dev, &min_freq))) {
+ dev_err(target_dev, "%s: Unable to find lowest opp\n",
+ __func__);
+ return -ENODEV;
+ }
+
+ max_freq = ULONG_MAX;
+ if (IS_ERR(opp_find_freq_floor(target_dev, &max_freq))) {
+ dev_err(target_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(target_dev, &freq);
+ if (IS_ERR(opp)) {
+ dev_err(target_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.
+ */
+
+ if (rate) {
+ dvfs_info = get_dvfs_info(od->hwmods[0]->voltdm);
+
+ ret = omap_dvfs_add_freq_request(dvfs_info, req_dev,
+ target_dev, freq);
+ if (ret) {
+ dev_err(target_dev, "%s: Unable to add frequency request\n",
+ __func__);
+ return ret;
+ }
+
+ ret = omap_dvfs_add_vdd_user(dvfs_info, req_dev, volt);
+ if (ret) {
+ dev_err(target_dev, "%s: Unable to add voltage request\n",
+ __func__);
+ omap_dvfs_remove_freq_request(dvfs_info, req_dev,
+ target_dev);
+ return ret;
+ }
+ } else {
+ dvfs_info = get_dvfs_info(od->hwmods[0]->voltdm);
+
+ ret = omap_dvfs_remove_freq_request(dvfs_info, req_dev,
+ target_dev);
+ if (ret) {
+ dev_err(target_dev, "%s: Unable to remove frequency request\n",
+ __func__);
+ return ret;
+ }
+
+ ret = omap_dvfs_remove_vdd_user(dvfs_info, req_dev);
+ if (ret) {
+ dev_err(target_dev, "%s: Unable to remove voltage request\n",
+ __func__);
+ return ret;
+ }
+ }
+
+ /* Do the actual scaling */
+ ret = omap_dvfs_voltage_scale(dvfs_info);
+ if (!ret)
+ if (omap_device_get_rate(target_dev) >= rate)
+ return 0;
+
+ return ret;
+}
+EXPORT_SYMBOL(omap_device_scale);
+
+/**
* omap_dvfs_init() - Initialize omap dvfs layer
*
* Initalizes omap dvfs layer. It basically allocates memory for
diff --git a/arch/arm/plat-omap/include/plat/dvfs.h b/arch/arm/plat-omap/include/plat/dvfs.h
index 1302990c27d..1be2b9d8bd3 100644
--- a/arch/arm/plat-omap/include/plat/dvfs.h
+++ b/arch/arm/plat-omap/include/plat/dvfs.h
@@ -17,11 +17,18 @@
#ifdef CONFIG_PM
int omap_dvfs_register_device(struct voltagedomain *voltdm, struct device *dev);
+int omap_device_scale(struct device *req_dev, struct device *dev,
+ unsigned long rate);
#else
static inline int omap_dvfs_register_device(struct voltagedomain *voltdm,
struct device *dev)
{
return -EINVAL;
}
+static inline int omap_device_scale(struct device *req_dev, struct devices
+ *target_dev, unsigned long rate);
+{
+ return -EINVAL;
+}
#endif
#endif