1 files changed, 134 insertions, 0 deletions

diff --git a/extras/recipes-kernel/linux/linux-omap/dvfs/0012-OMAP-Introduce-device-scale.patch b/extras/recipes-kernel/linux/linux-omap/dvfs/0012-OMAP-Introduce-device-scale.patch
new file mode 100644
index 00000000..a6d35bd6
--- /dev/null
+++ b/extras/recipes-kernel/linux/linux-omap/dvfs/0012-OMAP-Introduce-device-scale.patch
@@ -0,0 +1,134 @@
+From b461bd17384c73bbb243c54bf1d6466c94e594c3 Mon Sep 17 00:00:00 2001
+From: Thara Gopinath <thara@ti.com>
+Date: Fri, 2 Jul 2010 13:07:35 +0530
+Subject: [PATCH 12/20] OMAP: Introduce device scale
+
+This patch adds omap_device_scale API  which can be used to generic
+device rate scaling.
+
+Signed-off-by: Thara Gopinath <thara@ti.com>
+---
+ 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 1178b86..e44a0f7 100644
+--- a/arch/arm/plat-omap/include/plat/omap_device.h
++++ b/arch/arm/plat-omap/include/plat/omap_device.h
+@@ -117,6 +117,8 @@ 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 */
+ 
+@@ -126,7 +128,6 @@ 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 0d67af6..458d648 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>
+@@ -862,6 +863,83 @@ 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,
+-- 
+1.6.6.1
+