ARM: tegra: power: Separate throttling code
Alex Frid [Wed, 10 Aug 2011 21:42:54 +0000 (14:42 -0700)]
Moved tegra CPU throttling algorithm implementation into a separate
file. For now, the same algorithm is used for both Tegra2 and Tegra3
architecture.

Original-Change-Id: I478c32b5adee4c946472129b89615580c10b41e1
Reviewed-on: http://git-master/r/46748
Tested-by: Aleksandr Frid <afrid@nvidia.com>
Reviewed-by: Bitan Biswas <bbiswas@nvidia.com>
Reviewed-by: Scott Williams <scwilliams@nvidia.com>
Reviewed-by: Diwakar Tundlam <dtundlam@nvidia.com>
Reviewed-by: Anshul Jain (SW) <anshulj@nvidia.com>
Reviewed-by: Yu-Huan Hsu <yhsu@nvidia.com>

Rebase-Id: R2340f78e1d22942022e171044d6b20f260e2d312

arch/arm/mach-tegra/Makefile
arch/arm/mach-tegra/cpu-tegra.c
arch/arm/mach-tegra/cpu-tegra.h
arch/arm/mach-tegra/tegra2-throttle.c [new file with mode: 0644]

index bde11a8..8776f13 100644 (file)
@@ -76,6 +76,9 @@ obj-$(CONFIG_ARCH_TEGRA_2x_SOC)         += cpuidle-t2.o
 obj-$(CONFIG_ARCH_TEGRA_3x_SOC)         += cpuidle-t3.o
 endif
 endif
+ifeq ($(CONFIG_TEGRA_THERMAL_THROTTLE),y)
+obj-y                                   += tegra2-throttle.o
+endif
 obj-$(CONFIG_TEGRA_IOVMM)               += iovmm.o
 obj-$(CONFIG_TEGRA_IOVMM_GART)          += iovmm-gart.o
 obj-$(CONFIG_TEGRA_IOVMM_SMMU)          += iovmm-smmu.o
index aa2e572..b0163f0 100644 (file)
@@ -54,108 +54,16 @@ static DEFINE_MUTEX(tegra_cpu_lock);
 static bool is_suspended;
 static int suspend_index;
 
-unsigned int tegra_getspeed(unsigned int cpu);
-
 #ifdef CONFIG_TEGRA_THERMAL_THROTTLE
-/* CPU frequency is gradually lowered when throttling is enabled */
-#define THROTTLE_DELAY         msecs_to_jiffies(2000)
-
-static int is_throttling;
-static int throttle_lowest_index;
-static int throttle_highest_index;
-static int throttle_index;
-static int throttle_next_index;
-static struct delayed_work throttle_work;
-static struct workqueue_struct *workqueue;
-static DEFINE_MUTEX(tegra_throttle_lock);
-
-static void tegra_throttle_work_func(struct work_struct *work)
-{
-       unsigned int current_freq;
-
-       mutex_lock(&tegra_cpu_lock);
-       if (!is_throttling)
-               goto out;
-
-       current_freq = tegra_getspeed(0);
-       throttle_index = throttle_next_index;
-
-       if (freq_table[throttle_index].frequency < current_freq)
-               tegra_cpu_set_speed_cap(NULL);
-
-       if (throttle_index > throttle_lowest_index) {
-               throttle_next_index = throttle_index - 1;
-               queue_delayed_work(workqueue, &throttle_work, THROTTLE_DELAY);
-       }
-out:
-       mutex_unlock(&tegra_cpu_lock);
-}
-
-/*
- * tegra_throttling_enable
- * This function may sleep
- */
-void tegra_throttling_enable(bool enable)
-{
-       mutex_lock(&tegra_throttle_lock);
-       mutex_lock(&tegra_cpu_lock);
-
-       if (enable && !(is_throttling++)) {
-               unsigned int current_freq = tegra_getspeed(0);
-
-               for (throttle_index = throttle_highest_index;
-                    throttle_index >= throttle_lowest_index;
-                    throttle_index--)
-                       if (freq_table[throttle_index].frequency
-                           < current_freq)
-                               break;
-
-               throttle_index = max(throttle_index, throttle_lowest_index);
-               throttle_next_index = throttle_index;
-               queue_delayed_work(workqueue, &throttle_work, 0);
-       } else if (!enable && is_throttling) {
-               if (!(--is_throttling)) {
-                       /* restore speed requested by governor */
-                       tegra_cpu_set_speed_cap(NULL);
-
-                       mutex_unlock(&tegra_cpu_lock);
-                       cancel_delayed_work_sync(&throttle_work);
-                       mutex_unlock(&tegra_throttle_lock);
-                       return;
-               }
-       }
-       mutex_unlock(&tegra_cpu_lock);
-       mutex_unlock(&tegra_throttle_lock);
-}
-EXPORT_SYMBOL_GPL(tegra_throttling_enable);
-
-static unsigned int throttle_governor_speed(unsigned int requested_speed)
-{
-       return is_throttling ?
-               min(requested_speed, freq_table[throttle_index].frequency) :
-               requested_speed;
-}
 
 static ssize_t show_throttle(struct cpufreq_policy *policy, char *buf)
 {
-       return sprintf(buf, "%u\n", is_throttling);
+       return sprintf(buf, "%u\n", tegra_is_throttling());
 }
 
 cpufreq_freq_attr_ro(throttle);
 
 #ifdef CONFIG_DEBUG_FS
-static int throttle_debug_set(void *data, u64 val)
-{
-       tegra_throttling_enable(val);
-       return 0;
-}
-static int throttle_debug_get(void *data, u64 *val)
-{
-       *val = (u64) is_throttling;
-       return 0;
-}
-
-DEFINE_SIMPLE_ATTRIBUTE(throttle_fops, throttle_debug_get, throttle_debug_set, "%llu\n");
 
 static struct dentry *cpu_tegra_debugfs_root;
 
@@ -166,7 +74,7 @@ static int __init tegra_cpu_debug_init(void)
        if (!cpu_tegra_debugfs_root)
                return -ENOMEM;
 
-       if (!debugfs_create_file("throttle", 0644, cpu_tegra_debugfs_root, NULL, &throttle_fops))
+       if (tegra_throttle_debug_init(cpu_tegra_debugfs_root))
                goto err_out;
 
        return 0;
@@ -185,9 +93,6 @@ static void __exit tegra_cpu_debug_exit(void)
 late_initcall(tegra_cpu_debug_init);
 module_exit(tegra_cpu_debug_exit);
 #endif /* CONFIG_DEBUG_FS */
-
-#else /* CONFIG_TEGRA_THERMAL_THROTTLE */
-#define throttle_governor_speed(requested_speed) (requested_speed)
 #endif /* CONFIG_TEGRA_THERMAL_THROTTLE */
 
 #ifdef CONFIG_TEGRA_EDP_LIMITS
@@ -453,7 +358,7 @@ int tegra_cpu_set_speed_cap(unsigned int *speed_cap)
        if (is_suspended)
                return -EBUSY;
 
-       new_speed = throttle_governor_speed(new_speed);
+       new_speed = tegra_throttle_governor_speed(new_speed);
        new_speed = edp_governor_speed(new_speed);
        if (speed_cap)
                *speed_cap = new_speed;
@@ -591,21 +496,10 @@ static int __init tegra_cpufreq_init(void)
 
        suspend_index = table_data->suspend_index;
 
-#ifdef CONFIG_TEGRA_THERMAL_THROTTLE
-       /*
-        * High-priority, others flags default: not bound to a specific
-        * CPU, has rescue worker task (in case of allocation deadlock,
-        * etc.).  Single-threaded.
-        */
-       workqueue = alloc_workqueue("cpu-tegra",
-                                   WQ_HIGHPRI | WQ_UNBOUND | WQ_RESCUER, 1);
-       if (!workqueue)
-               return -ENOMEM;
-       INIT_DELAYED_WORK(&throttle_work, tegra_throttle_work_func);
+       ret = tegra_throttle_init(&tegra_cpu_lock);
+       if (ret)
+               return ret;
 
-       throttle_lowest_index = table_data->throttle_lowest_index;
-       throttle_highest_index = table_data->throttle_highest_index;
-#endif
        ret = tegra_auto_hotplug_init(&tegra_cpu_lock);
        if (ret)
                return ret;
@@ -617,9 +511,7 @@ static int __init tegra_cpufreq_init(void)
 
 static void __exit tegra_cpufreq_exit(void)
 {
-#ifdef CONFIG_TEGRA_THERMAL_THROTTLE
-       destroy_workqueue(workqueue);
-#endif
+       tegra_throttle_exit();
        tegra_cpu_edp_exit();
        tegra_auto_hotplug_exit();
        cpufreq_unregister_driver(&tegra_cpufreq_driver);
index eaa2305..b47828f 100644 (file)
@@ -21,6 +21,7 @@
 #ifndef __MACH_TEGRA_CPU_TEGRA_H
 #define __MACH_TEGRA_CPU_TEGRA_H
 
+unsigned int tegra_getspeed(unsigned int cpu);
 int tegra_cpu_set_speed_cap(unsigned int *speed_cap);
 unsigned int tegra_count_slow_cpus(unsigned long speed_limit);
 unsigned int tegra_get_slowest_cpu_n(void);
@@ -28,8 +29,25 @@ unsigned long tegra_cpu_lowest_speed(void);
 unsigned long tegra_cpu_highest_speed(void);
 
 #ifdef CONFIG_TEGRA_THERMAL_THROTTLE
+int tegra_throttle_init(struct mutex *cpu_lock);
+void tegra_throttle_exit(void);
+bool tegra_is_throttling(void);
+unsigned int tegra_throttle_governor_speed(unsigned int requested_speed);
+int tegra_throttle_debug_init(struct dentry *cpu_tegra_debugfs_root);
 void tegra_throttling_enable(bool enable);
 #else
+static inline int tegra_throttle_init(struct mutex *cpu_lock)
+{ return 0; }
+static inline void tegra_throttle_exit(void)
+{}
+static inline bool tegra_is_throttling(void)
+{ return false; }
+static inline unsigned int tegra_throttle_governor_speed(
+       unsigned int requested_speed)
+{ return requested_speed; }
+static inline int tegra_throttle_debug_init(
+       struct dentry *cpu_tegra_debugfs_root)
+{ return 0; }
 #define tegra_throttling_enable NULL
 #endif /* CONFIG_TEGRA_THERMAL_THROTTLE */
 
diff --git a/arch/arm/mach-tegra/tegra2-throttle.c b/arch/arm/mach-tegra/tegra2-throttle.c
new file mode 100644 (file)
index 0000000..dd0d1d7
--- /dev/null
@@ -0,0 +1,180 @@
+/*
+ * arch/arm/mach-tegra/tegra2-throttle.c
+ *
+ * Copyright (C) 2010 Google, Inc.
+ *
+ * Author:
+ *     Colin Cross <ccross@google.com>
+ *     Based on arch/arm/plat-omap/cpu-omap.c, (C) 2005 Nokia Corporation
+ *
+ * Copyright (C) 2010-2011 NVIDIA Corporation
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/sched.h>
+#include <linux/cpufreq.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/err.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/debugfs.h>
+
+#include "clock.h"
+#include "cpu-tegra.h"
+
+/* tegra throttling require frequencies in the table to be in ascending order */
+static struct cpufreq_frequency_table *throttle_table;
+static struct mutex *cpu_throttle_lock;
+
+/* CPU frequency is gradually lowered when throttling is enabled */
+#define THROTTLE_DELAY         msecs_to_jiffies(2000)
+
+static int is_throttling;
+static int throttle_lowest_index;
+static int throttle_highest_index;
+static int throttle_index;
+static int throttle_next_index;
+static struct delayed_work throttle_work;
+static struct workqueue_struct *workqueue;
+static DEFINE_MUTEX(tegra_throttle_lock);
+
+static void tegra_throttle_work_func(struct work_struct *work)
+{
+       unsigned int current_freq;
+
+       mutex_lock(cpu_throttle_lock);
+       if (!is_throttling)
+               goto out;
+
+       current_freq = tegra_getspeed(0);
+       throttle_index = throttle_next_index;
+
+       if (throttle_table[throttle_index].frequency < current_freq)
+               tegra_cpu_set_speed_cap(NULL);
+
+       if (throttle_index > throttle_lowest_index) {
+               throttle_next_index = throttle_index - 1;
+               queue_delayed_work(workqueue, &throttle_work, THROTTLE_DELAY);
+       }
+out:
+       mutex_unlock(cpu_throttle_lock);
+}
+
+/*
+ * tegra_throttling_enable
+ * This function may sleep
+ */
+void tegra_throttling_enable(bool enable)
+{
+       mutex_lock(&tegra_throttle_lock);
+       mutex_lock(cpu_throttle_lock);
+
+       if (enable && !(is_throttling++)) {
+               unsigned int current_freq = tegra_getspeed(0);
+
+               for (throttle_index = throttle_highest_index;
+                    throttle_index >= throttle_lowest_index;
+                    throttle_index--)
+                       if (throttle_table[throttle_index].frequency
+                           < current_freq)
+                               break;
+
+               throttle_index = max(throttle_index, throttle_lowest_index);
+               throttle_next_index = throttle_index;
+               queue_delayed_work(workqueue, &throttle_work, 0);
+       } else if (!enable && is_throttling) {
+               if (!(--is_throttling)) {
+                       /* restore speed requested by governor */
+                       tegra_cpu_set_speed_cap(NULL);
+
+                       mutex_unlock(cpu_throttle_lock);
+                       cancel_delayed_work_sync(&throttle_work);
+                       mutex_unlock(&tegra_throttle_lock);
+                       return;
+               }
+       }
+       mutex_unlock(cpu_throttle_lock);
+       mutex_unlock(&tegra_throttle_lock);
+}
+EXPORT_SYMBOL_GPL(tegra_throttling_enable);
+
+unsigned int tegra_throttle_governor_speed(unsigned int requested_speed)
+{
+       return is_throttling ?
+               min(requested_speed, throttle_table[throttle_index].frequency) :
+               requested_speed;
+}
+
+bool tegra_is_throttling(void)
+{
+       return is_throttling;
+}
+
+int __init tegra_throttle_init(struct mutex *cpu_lock)
+{
+       struct tegra_cpufreq_table_data *table_data =
+               tegra_cpufreq_table_get();
+       if (IS_ERR_OR_NULL(table_data))
+               return -EINVAL;
+
+       /*
+        * High-priority, others flags default: not bound to a specific
+        * CPU, has rescue worker task (in case of allocation deadlock,
+        * etc.).  Single-threaded.
+        */
+       workqueue = alloc_workqueue("cpu-tegra",
+                                   WQ_HIGHPRI | WQ_UNBOUND | WQ_RESCUER, 1);
+       if (!workqueue)
+               return -ENOMEM;
+       INIT_DELAYED_WORK(&throttle_work, tegra_throttle_work_func);
+
+       throttle_lowest_index = table_data->throttle_lowest_index;
+       throttle_highest_index = table_data->throttle_highest_index;
+       throttle_table = table_data->freq_table;
+       cpu_throttle_lock = cpu_lock;
+
+       return 0;
+}
+
+void tegra_throttle_exit(void)
+{
+       destroy_workqueue(workqueue);
+}
+
+#ifdef CONFIG_DEBUG_FS
+
+static int throttle_debug_set(void *data, u64 val)
+{
+       tegra_throttling_enable(val);
+       return 0;
+}
+static int throttle_debug_get(void *data, u64 *val)
+{
+       *val = (u64) is_throttling;
+       return 0;
+}
+DEFINE_SIMPLE_ATTRIBUTE(throttle_fops, throttle_debug_get, throttle_debug_set,
+                       "%llu\n");
+
+int __init tegra_throttle_debug_init(struct dentry *cpu_tegra_debugfs_root)
+{
+       if (!debugfs_create_file("throttle", 0644, cpu_tegra_debugfs_root,
+                                NULL, &throttle_fops))
+               return -ENOMEM;
+       return 0;
+}
+#endif /* CONFIG_DEBUG_FS */
+