ARM: tegra: power: Add initial SiMon support

Defined tegra Silicon Monitor (SiMon) domains: CPU, GPU, core. Added
SiMon domain grade notification chain, and debugfs entries.

Bug 1343366

Change-Id: Ieff7ca57af48e5a5a2224fd6800bcccabf8eef5e
Signed-off-by: Alex Frid <afrid@nvidia.com>
Reviewed-on: http://git-master/r/338521
Reviewed-by: Automatic_Commit_Validation_User
GVS: Gerrit_Virtual_Submit
Reviewed-by: Sai Gurrappadi <sgurrappadi@nvidia.com>
Reviewed-by: Yu-Huan Hsu <yhsu@nvidia.com>

1 files changed, 129 insertions, 0 deletions

diff --git a/arch/arm/mach-tegra/tegra_simon.c b/arch/arm/mach-tegra/tegra_simon.c
new file mode 100644
index 000000000000..3f45b853c42c
--- /dev/null
+++ b/arch/arm/mach-tegra/tegra_simon.c
@@ -0,0 +1,129 @@
+/*
+ * arch/arm/mach-tegra/tegra_simon.c
+ *
+ * Copyright (c) 2013, NVIDIA CORPORATION. All rights reserved.
+ *
+ * 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/init.h>
+#include <linux/module.h>
+#include <linux/err.h>
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+
+#include "tegra_simon.h"
+
+static DEFINE_MUTEX(simon_lock);
+static RAW_NOTIFIER_HEAD(simon_nh);
+static int simon_grades[TEGRA_SIMON_DOMAIN_NUM];
+
+static const char *simon_domain_names[TEGRA_SIMON_DOMAIN_NUM] = {
+	[TEGRA_SIMON_DOMAIN_CPU] = "cpu",
+	[TEGRA_SIMON_DOMAIN_GPU] = "gpu",
+	[TEGRA_SIMON_DOMAIN_CORE] = "core",
+};
+
+
+int tegra_register_simon_notifier(struct notifier_block *nb)
+{
+	int ret;
+
+	mutex_lock(&simon_lock);
+	ret = raw_notifier_chain_register(&simon_nh, nb);
+	mutex_unlock(&simon_lock);
+	return ret;
+}
+
+void tegra_unregister_simon_notifier(struct notifier_block *nb)
+{
+	mutex_lock(&simon_lock);
+	raw_notifier_chain_unregister(&simon_nh, nb);
+	mutex_unlock(&simon_lock);
+}
+
+static int simon_grade_change_notify(int grade, enum tegra_simon_domain domain)
+{
+	int ret = 0;
+
+	mutex_lock(&simon_lock);
+	if (simon_grades[domain] != grade) {
+		simon_grades[domain] = grade;
+		ret = raw_notifier_call_chain(&simon_nh, grade, (void *)domain);
+	}
+	mutex_unlock(&simon_lock);
+	return ret;
+}
+
+#ifdef CONFIG_DEBUG_FS
+
+static int grade_get(void *data, u64 *val)
+{
+	int domain = (int)data;
+
+	if (domain >= TEGRA_SIMON_DOMAIN_NUM) {
+		*val = -EINVAL;
+		return -EINVAL;
+	}
+
+	*val = simon_grades[domain];
+	return 0;
+}
+static int grade_set(void *data, u64 val)
+{
+	int domain = (int)data;
+
+	if (domain >= TEGRA_SIMON_DOMAIN_NUM)
+		return -EINVAL;
+
+	simon_grade_change_notify(val, domain);
+	return 0;
+}
+DEFINE_SIMPLE_ATTRIBUTE(grade_fops, grade_get, grade_set, "%llu\n");
+
+static int __init simon_debugfs_init(void)
+{
+	int domain;
+	struct dentry *d, *dir;
+
+	dir = debugfs_create_dir("tegra_simon", NULL);
+	if (!dir)
+		return -ENOMEM;
+
+	for (domain = 0; domain < TEGRA_SIMON_DOMAIN_NUM; domain++) {
+		if (!simon_domain_names[domain])
+			continue;
+
+		d = debugfs_create_file(simon_domain_names[domain],
+			S_IWUSR | S_IRUGO, dir, (void *)domain, &grade_fops);
+		if (!d)
+			goto err_out;
+	}
+
+	return 0;
+
+err_out:
+	debugfs_remove_recursive(dir);
+	return -ENOMEM;
+}
+#endif
+
+static int __init tegra_simon_init(void)
+{
+#ifdef CONFIG_DEBUG_FS
+	simon_debugfs_init();
+#endif
+	return 0;
+
+}
+late_initcall_sync(tegra_simon_init);
+