--- /dev/null
+/*
+ * Copyright (c) 2014, NVIDIA CORPORATION. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/devfreq.h>
+#include <linux/debugfs.h>
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/device.h>
+#include <linux/notifier.h>
+#include <linux/platform_device.h>
+
+#include <governor.h>
+
+enum watermark_type {
+ NO_WATERMARK_EVENT = 0,
+ HIGH_WATERMARK_EVENT = 1,
+ LOW_WATERMARK_EVENT = 2
+};
+
+struct wmark_gov_info {
+ unsigned long *freqlist;
+ int freq_count;
+ unsigned long last_request;
+
+ enum watermark_type event;
+
+ struct devfreq *df;
+ struct platform_device *pdev;
+};
+
+static unsigned long freqlist_up(struct wmark_gov_info *wmarkinfo,
+ unsigned long curr_freq)
+{
+ int i, pos;
+
+ for (i = 0; i < wmarkinfo->freq_count; i++)
+ if (wmarkinfo->freqlist[i] > curr_freq)
+ break;
+
+ pos = min(wmarkinfo->freq_count - 1, i);
+
+ return wmarkinfo->freqlist[pos];
+}
+
+static unsigned long freqlist_down(struct wmark_gov_info *wmarkinfo,
+ unsigned long curr_freq)
+{
+ int i, pos;
+
+ for (i = wmarkinfo->freq_count - 1; i >= 0; i--)
+ if (wmarkinfo->freqlist[i] < curr_freq)
+ break;
+
+ pos = max(0, i);
+ return wmarkinfo->freqlist[pos];
+}
+
+static int devfreq_watermark_target_freq(struct devfreq *df,
+ unsigned long *freq)
+{
+ struct wmark_gov_info *wmarkinfo = df->data;
+ struct devfreq_dev_status dev_stat;
+ int err;
+
+ err = df->profile->get_dev_status(df->dev.parent, &dev_stat);
+ if (err < 0)
+ return err;
+
+ switch (wmarkinfo->event) {
+ case HIGH_WATERMARK_EVENT:
+ *freq = freqlist_up(wmarkinfo, dev_stat.current_frequency);
+
+ /* always enable low watermark */
+ df->profile->set_low_wmark(df->dev.parent, 100);
+
+ /* disable high watermark if no change */
+ if (*freq == wmarkinfo->last_request)
+ df->profile->set_high_wmark(df->dev.parent, 1000);
+ break;
+ case LOW_WATERMARK_EVENT:
+ *freq = freqlist_down(wmarkinfo, dev_stat.current_frequency);
+
+ /* always enable high watermark */
+ df->profile->set_high_wmark(df->dev.parent, 600);
+
+ /* disable low watermark if no change */
+ if (*freq == wmarkinfo->last_request)
+ df->profile->set_low_wmark(df->dev.parent, 0);
+ break;
+ default:
+ break;
+ }
+
+ /* Mark that you handled event */
+ wmarkinfo->event = NO_WATERMARK_EVENT;
+ wmarkinfo->last_request = *freq;
+
+ return 0;
+}
+
+static int devfreq_watermark_start(struct devfreq *df)
+{
+ struct wmark_gov_info *wmarkinfo;
+ struct platform_device *pdev = to_platform_device(df->dev.parent);
+
+ if (!df->profile->freq_table) {
+ dev_err(&pdev->dev, "Frequency table missing\n");
+ return -EINVAL;
+ }
+
+ wmarkinfo = kzalloc(sizeof(struct wmark_gov_info), GFP_KERNEL);
+ if (!wmarkinfo)
+ return -ENOMEM;
+
+ df->data = (void *)wmarkinfo;
+ wmarkinfo->freqlist = df->profile->freq_table;
+ wmarkinfo->freq_count = df->profile->max_state;
+ wmarkinfo->event = NO_WATERMARK_EVENT;
+ wmarkinfo->df = df;
+ wmarkinfo->pdev = pdev;
+
+ return 0;
+}
+
+static int devfreq_watermark_event_handler(struct devfreq *df,
+ unsigned int event, void *wmark_type)
+{
+ int ret = 0;
+ struct wmark_gov_info *wmarkinfo = df->data;
+ enum watermark_type *type = wmark_type;
+
+ switch (event) {
+ case DEVFREQ_GOV_START:
+ devfreq_watermark_start(df);
+ if (df->profile->set_low_wmark)
+ df->profile->set_low_wmark(df->dev.parent, 100);
+ if (df->profile->set_high_wmark)
+ df->profile->set_high_wmark(df->dev.parent, 600);
+ break;
+ case DEVFREQ_GOV_STOP:
+ break;
+ case DEVFREQ_GOV_SUSPEND:
+ devfreq_monitor_suspend(df);
+ break;
+
+ case DEVFREQ_GOV_RESUME:
+ if (df->profile->set_low_wmark)
+ df->profile->set_low_wmark(df->dev.parent, 100);
+ if (df->profile->set_high_wmark)
+ df->profile->set_high_wmark(df->dev.parent, 600);
+ devfreq_monitor_resume(df);
+ break;
+
+ case DEVFREQ_GOV_WMARK:
+ /* Set watermark interrupt type */
+ wmarkinfo->event = *type;
+
+ mutex_lock(&df->lock);
+ update_devfreq(df);
+ mutex_unlock(&df->lock);
+
+ break;
+
+ default:
+ break;
+ }
+
+ return ret;
+}
+
+static struct devfreq_governor devfreq_watermark = {
+ .name = "watermark",
+ .get_target_freq = devfreq_watermark_target_freq,
+ .event_handler = devfreq_watermark_event_handler,
+};
+
+
+static int __init devfreq_watermark_init(void)
+{
+ return devfreq_add_governor(&devfreq_watermark);
+}
+
+static void __exit devfreq_watermark_exit(void)
+{
+ devfreq_remove_governor(&devfreq_watermark);
+}
+
+rootfs_initcall(devfreq_watermark_init);
+module_exit(devfreq_watermark_exit);
projects / sojka / nv-tegra / linux-3.10.git / commitdiff