ARM: tegra: dvfs: Add DVFS rails statistic

On Tegra3: complete account of in- and out-of-bound rails control.
On Tegra2: out-of-bound vdd_cpu control in LP2 state is not accounted.

Change-Id: Ib68cbbfe3e4f965e758aca17a0ba30277d530347
Signed-off-by: Alex Frid <afrid@nvidia.com>
Reviewed-on: http://git-master/r/67340
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Yu-Huan Hsu <yhsu@nvidia.com>

Rebase-Id: Rf2aa9242f09fc393fa5114cd059894ebdbeedcee

1 files changed, 127 insertions, 0 deletions

diff --git a/arch/arm/mach-tegra/dvfs.c b/arch/arm/mach-tegra/dvfs.c
index c39a10a9e46b..22c666081c90 100644
--- a/arch/arm/mach-tegra/dvfs.c
+++ b/arch/arm/mach-tegra/dvfs.c
@@ -39,6 +39,11 @@
 #include "clock.h"
 #include "dvfs.h"
 
+#define DVFS_RAIL_STATS_BIN	25
+#define DVFS_RAIL_STATS_SCALE	2
+#define DVFS_RAIL_STATS_RANGE   ((DVFS_RAIL_STATS_TOP_BIN - 1) * \
+				 DVFS_RAIL_STATS_BIN / DVFS_RAIL_STATS_SCALE)
+
 static LIST_HEAD(dvfs_rail_list);
 static DEFINE_MUTEX(dvfs_lock);
 static DEFINE_MUTEX(rail_disable_lock);
@@ -89,6 +94,74 @@ static int dvfs_solve_relationship(struct dvfs_relationship *rel)
 	return rel->solve(rel->from, rel->to);
 }
 
+/* rail statistic - called during rail init, or under dfs_lock, or with
+   CPU0 only on-line, and interrupts disabled */
+static void dvfs_rail_stats_init(struct dvfs_rail *rail, int millivolts)
+{
+	rail->stats.last_update = ktime_get();
+	if (millivolts >= rail->min_millivolts) {
+		int i = 1 + (2 * (millivolts - rail->min_millivolts) *
+			DVFS_RAIL_STATS_SCALE + DVFS_RAIL_STATS_BIN) /
+			(2 * DVFS_RAIL_STATS_BIN);
+		rail->stats.last_index = min(i, DVFS_RAIL_STATS_TOP_BIN);
+	}
+
+	if (rail->max_millivolts >
+	    rail->min_millivolts + DVFS_RAIL_STATS_RANGE)
+		pr_warn("tegra_dvfs: %s: stats above %d mV will be squashed\n",
+			rail->reg_id,
+			rail->min_millivolts + DVFS_RAIL_STATS_RANGE);
+}
+
+static void dvfs_rail_stats_update(
+	struct dvfs_rail *rail, int millivolts, ktime_t now)
+{
+	rail->stats.time_at_mv[rail->stats.last_index] = ktime_add(
+		rail->stats.time_at_mv[rail->stats.last_index], ktime_sub(
+			now, rail->stats.last_update));
+	rail->stats.last_update = now;
+
+	if (rail->stats.off)
+		return;
+
+	if (millivolts >= rail->min_millivolts) {
+		int i = 1 + (2 * (millivolts - rail->min_millivolts) *
+			DVFS_RAIL_STATS_SCALE + DVFS_RAIL_STATS_BIN) /
+			(2 * DVFS_RAIL_STATS_BIN);
+		rail->stats.last_index = min(i, DVFS_RAIL_STATS_TOP_BIN);
+	} else if (millivolts == 0)
+			rail->stats.last_index = 0;
+}
+
+static void dvfs_rail_stats_pause(struct dvfs_rail *rail,
+				  ktime_t delta, bool on)
+{
+	int i = on ? rail->stats.last_index : 0;
+	rail->stats.time_at_mv[i] = ktime_add(rail->stats.time_at_mv[i], delta);
+}
+
+void tegra_dvfs_rail_off(struct dvfs_rail *rail, ktime_t now)
+{
+	if (rail) {
+		dvfs_rail_stats_update(rail, 0, now);
+		rail->stats.off = true;
+	}
+}
+
+void tegra_dvfs_rail_on(struct dvfs_rail *rail, ktime_t now)
+{
+	if (rail) {
+		rail->stats.off = false;
+		dvfs_rail_stats_update(rail, rail->millivolts, now);
+	}
+}
+
+void tegra_dvfs_rail_pause(struct dvfs_rail *rail, ktime_t delta, bool on)
+{
+	if (rail)
+		dvfs_rail_stats_pause(rail, delta, on);
+}
+
 /* Sets the voltage on a dvfs rail to a specific value, and updates any
  * rails that depend on this rail. */
 static int dvfs_rail_set_voltage(struct dvfs_rail *rail, int millivolts)
@@ -148,6 +221,7 @@ static int dvfs_rail_set_voltage(struct dvfs_rail *rail, int millivolts)
 		}
 
 		rail->millivolts = rail->new_millivolts;
+		dvfs_rail_stats_update(rail, rail->millivolts, ktime_get());
 
 		/* After changing the voltage, tell each rail that depends
 		 * on this rail that the voltage has changed.
@@ -242,6 +316,7 @@ static int dvfs_rail_connect_to_regulator(struct dvfs_rail *rail)
 	}
 	rail->millivolts = v / 1000;
 	rail->new_millivolts = rail->millivolts;
+	dvfs_rail_stats_init(rail, rail->millivolts);
 	return 0;
 }
 
@@ -664,6 +739,53 @@ static const struct file_operations dvfs_tree_fops = {
 	.release	= single_release,
 };
 
+static int rail_stats_show(struct seq_file *s, void *data)
+{
+	int i;
+	struct dvfs_rail *rail;
+
+	seq_printf(s, "%-12s %-10s (bin: %d.%dmV)\n", "millivolts", "time",
+		   DVFS_RAIL_STATS_BIN / DVFS_RAIL_STATS_SCALE,
+		   ((DVFS_RAIL_STATS_BIN * 100) / DVFS_RAIL_STATS_SCALE) % 100);
+
+	mutex_lock(&dvfs_lock);
+
+	list_for_each_entry(rail, &dvfs_rail_list, node) {
+		seq_printf(s, "%s\n", rail->reg_id);
+		dvfs_rail_stats_update(rail, -1, ktime_get());
+
+		seq_printf(s, "%-12d %-10llu\n", 0,
+			cputime64_to_clock_t(msecs_to_jiffies(
+				ktime_to_ms(rail->stats.time_at_mv[0]))));
+
+		for (i = 1; i <= DVFS_RAIL_STATS_TOP_BIN; i++) {
+			ktime_t ktime_zero = ktime_set(0, 0);
+			if (ktime_equal(rail->stats.time_at_mv[i], ktime_zero))
+				continue;
+			seq_printf(s, "%-12d %-10llu\n",
+				   rail->min_millivolts + (i - 1) *
+				   DVFS_RAIL_STATS_BIN / DVFS_RAIL_STATS_SCALE,
+				cputime64_to_clock_t(msecs_to_jiffies(
+					ktime_to_ms(rail->stats.time_at_mv[i])))
+			);
+		}
+	}
+	mutex_unlock(&dvfs_lock);
+	return 0;
+}
+
+static int rail_stats_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, rail_stats_show, inode->i_private);
+}
+
+static const struct file_operations rail_stats_fops = {
+	.open		= rail_stats_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
 int __init dvfs_debugfs_init(struct dentry *clk_debugfs_root)
 {
 	struct dentry *d;
@@ -673,6 +795,11 @@ int __init dvfs_debugfs_init(struct dentry *clk_debugfs_root)
 	if (!d)
 		return -ENOMEM;
 
+	d = debugfs_create_file("rails", S_IRUGO, clk_debugfs_root, NULL,
+		&rail_stats_fops);
+	if (!d)
+		return -ENOMEM;
+
 	return 0;
 }