regulator: add a data summary tree in debugfs

On modern systems the regulator hierarchy can get quite long and nested with regulators supplying other regulators. In some cases when debugging it might be nice to get a tree of these regulators, their consumers and the regulation constraints in one go.

To achieve this add a regulator_summary sysfs node, similar to clk_summary in the common clock framework, that walks the regulator list and creates a tree out of the regulators, their consumers and core per-regulator settings.

On a rk3288-firefly the regulator_summary would for example look something like:

regulator use,open,bypass value min max
--------------------------------------------------------------------------------

 vcc_sys                          0,  12,     0     5000mV     5000mV     5000mV
    vcc_lan                       1,   1,     0     3300mV     3300mV     3300mV

ff290000.ethernet 0mV 0mV
vcca_33 0, 0, 0 3300mV 3300mV 3300mV
vcca_18 0, 0, 0 1800mV 1800mV 1800mV
vdd10_lcd 0, 0, 0 1000mV 1000mV 1000mV
vccio_sd 0, 0, 0 3300mV 3300mV 3300mV
vcc_20 0, 3, 0 2000mV 2000mV 2000mV
vcc18_lcd 0, 0, 0 1800mV 1800mV 1800mV
vcc_18 0, 2, 0 1800mV 1800mV 1800mV
ff100000.saradc 0mV 0mV
ff0d0000.dwmmc 1650mV 1950mV
vdd_10 0, 0, 0 1000mV 1000mV 1000mV
vdd_log 0, 0, 0 1100mV 1100mV 1100mV
vcc_io 0, 3, 0 3300mV 3300mV 3300mV
ff0f0000.dwmmc 3300mV 3400mV
vcc_flash 1, 1, 0 1800mV 1800mV 1800mV
ff0f0000.dwmmc 1700mV 1950mV
vcc_sd 1, 1, 0 3300mV 3300mV 3300mV
ff0c0000.dwmmc 3300mV 3400mV
vcc_ddr 0, 0, 0 1200mV 1200mV 1200mV
vdd_gpu 0, 0, 0 1000mV 850mV 1350mV
vdd_cpu 0, 1, 0 900mV 850mV 1350mV
cpu0 900mV 900mV
vcc_5v 0, 2, 0 5000mV 5000mV 5000mV
vcc_otg_5v 0, 0, 0 5000mV 5000mV 5000mV
vcc_host_5v 0, 0, 0 5000mV 5000mV 5000mV

---
 drivers/regulator/core.c | 113 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 113 insertions(+)

index a4a8a6d..950fe22 100644
@@ -3936,6 +3936,116 @@ static const struct file_operations supply_map_fops = {
 #endif
 };
 
+#ifdef CONFIG_DEBUG_FS
+static void regulator_summary_show_subtree(struct seq_file *s,
+					   struct regulator_dev *rdev,
+					   int level)
+{
+	struct list_head *list = s->private;
+	struct regulator_dev *child;
+	struct regulation_constraints *c;
+	struct regulator *consumer;
+
+	if (!rdev)
+		return;
+
+	mutex_lock(&rdev->mutex);
+
+	seq_printf(s, "%*s%-*s %3d,%4d,%6d ",
+		   level * 3 + 1, "",
+		   30 - level * 3, rdev_get_name(rdev),
+		   rdev->use_count, rdev->open_count, rdev->bypass_count);
+
+	switch (rdev->desc->type) {
+	case REGULATOR_VOLTAGE:
+		seq_printf(s, "%8dmV ",
+			   _regulator_get_voltage(rdev) / 1000);
+		break;
+	case REGULATOR_CURRENT:
+		seq_printf(s, "%8dmA ",
+			   _regulator_get_current_limit(rdev) / 1000);
+		break;
+	}
+
+	c = rdev->constraints;
+	if (c) {
+		switch (rdev->desc->type) {
+		case REGULATOR_VOLTAGE:
+			seq_printf(s, "%8dmV %8dmV ",
+				   c->min_uV / 1000, c->max_uV / 1000);
+			break;
+		case REGULATOR_CURRENT:
+			seq_printf(s, "%8dmA %8dmA ",
+				   c->min_uA / 1000, c->max_uA / 1000);
+			break;
+		}
+	}
+
+	seq_puts(s, "\n");
+
+	list_for_each_entry(consumer, &rdev->consumer_list, list) {
+		if (consumer->dev->class == &regulator_class)
+			continue;
+
+		seq_printf(s, "%*s%-*s ",
+			   (level + 1) * 3 + 1, "",
+		   30 - (level + 1) * 3, dev_name(consumer->dev));
+
+		if (rdev->desc->type == REGULATOR_VOLTAGE)
+			seq_printf(s, "%35dmV %8dmV",
+				   consumer->min_uV / 1000,
+				   consumer->max_uV / 1000);
+
+		seq_puts(s, "\n");
+	}
+
+	mutex_unlock(&rdev->mutex);
+
+	list_for_each_entry(child, list, list) {
+		if (!child->supply || child->supply->rdev != rdev)
+			continue;
+
+		regulator_summary_show_subtree(s, child, level + 1);
+	}
+}
+
+static int regulator_summary_show(struct seq_file *s, void *data)
+{
+	struct list_head *list = s->private;
+	struct regulator_dev *rdev;
+
+	seq_puts(s, " regulator                      use,open,bypass      value        min        max\n");
+	seq_puts(s, "--------------------------------------------------------------------------------\n");
+
+	mutex_lock(&regulator_list_mutex);
+
+	list_for_each_entry(rdev, list, list) {
+		if (rdev->supply)
+			continue;
+
+		regulator_summary_show_subtree(s, rdev, 0);
+	}
+
+	mutex_unlock(&regulator_list_mutex);
+
+	return 0;
+}
+
+static int regulator_summary_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, regulator_summary_show, inode->i_private);
+}
+#endif
+
+static const struct file_operations regulator_summary_fops = {
+#ifdef CONFIG_DEBUG_FS
+	.open		= regulator_summary_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+#endif
+};
+
 static int __init regulator_init(void)
 {
 	int ret;

@@ -3949,6 +4059,9 @@ static int __init regulator_init(void)
 	debugfs_create_file("supply_map", 0444, debugfs_root, NULL,
 			    &supply_map_fops);
 
+	debugfs_create_file("regulator_summary", 0444, debugfs_root,
+			    &regulator_list, &regulator_summary_fops);
+
 	regulator_dummy_init();
 
 	return ret;

2.1.4

On modern systems the regulator hierarchy can get quite long and nested with regulators supplying other regulators. In some cases when debugging it might be nice to get a tree of these regulators, their consumers and the regulation constraints in one go.

To achieve this add a regulator_summary sysfs node, similar to clk_summary in the common clock framework, that walks the regulator list and creates a tree out of the regulators, their consumers and core per-regulator settings.

On a rk3288-firefly the regulator_summary would for example look something like:

regulator use open bypass value min max
-----------------------------------------------------------------------

 vcc_sys                          0   12      0  5000mV  5000mV  5000mV
    vcc_lan                       1    1      0  3300mV  3300mV  3300mV

ff290000.ethernet 0mV 0mV
vcca_33 0 0 0 3300mV 3300mV 3300mV
vcca_18 0 0 0 1800mV 1800mV 1800mV
vdd10_lcd 0 0 0 1000mV 1000mV 1000mV
vccio_sd 0 0 0 3300mV 3300mV 3300mV
vcc_20 0 3 0 2000mV 2000mV 2000mV
vcc18_lcd 0 0 0 1800mV 1800mV 1800mV
vcc_18 0 2 0 1800mV 1800mV 1800mV
ff100000.saradc 0mV 0mV
ff0d0000.dwmmc 1650mV 1950mV
vdd_10 0 0 0 1000mV 1000mV 1000mV
vdd_log 0 0 0 1100mV 1100mV 1100mV
vcc_io 0 3 0 3300mV 3300mV 3300mV
ff0f0000.dwmmc 3300mV 3400mV
vcc_flash 1 1 0 1800mV 1800mV 1800mV
ff0f0000.dwmmc 1700mV 1950mV
vcc_sd 1 1 0 3300mV 3300mV 3300mV
ff0c0000.dwmmc 3300mV 3400mV
vcc_ddr 0 0 0 1200mV 1200mV 1200mV
vdd_gpu 0 0 0 1000mV 850mV 1350mV
vdd_cpu 0 1 0 900mV 850mV 1350mV
cpu0 900mV 900mV
vcc_5v 0 2 0 5000mV 5000mV 5000mV
vcc_otg_5v 0 0 0 5000mV 5000mV 5000mV
vcc_host_5v 0 0 0 5000mV 5000mV 5000mV
regulator-dummy 0 0 0 0mV 0mV 0mV

---
changes since v1:
- comsetics: space instead of ","; decrease width of voltage/current columns
- output current-limit for current regulators

The questioned statement

is meant to single out only those regulators from the global list that are actual children of the current rdev. Regulators with !child->supply are the root ones and handled in regulator_summary_show while regulators with different parents will be handled when their parent is processed.

So there shouldn't be a need to complain. Or alternatively I'm just overlooking a different way to do the whole parent->children resolution.

 drivers/regulator/core.c | 121 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 121 insertions(+)

index a4a8a6d..fb2c8d5 100644
@@ -3936,6 +3936,124 @@ static const struct file_operations supply_map_fops = {
 #endif
 };
 
+#ifdef CONFIG_DEBUG_FS
+static void regulator_summary_show_subtree(struct seq_file *s,
+					   struct regulator_dev *rdev,
+					   int level)
+{
+	struct list_head *list = s->private;
+	struct regulator_dev *child;
+	struct regulation_constraints *c;
+	struct regulator *consumer;
+
+	if (!rdev)
+		return;
+
+	mutex_lock(&rdev->mutex);
+
+	seq_printf(s, "%*s%-*s %3d %4d %6d ",
+		   level * 3 + 1, "",
+		   30 - level * 3, rdev_get_name(rdev),
+		   rdev->use_count, rdev->open_count, rdev->bypass_count);
+
+	switch (rdev->desc->type) {
+	case REGULATOR_VOLTAGE:
+		seq_printf(s, "%5dmV ",
+			   _regulator_get_voltage(rdev) / 1000);
+		break;
+	case REGULATOR_CURRENT:
+		seq_printf(s, "%5dmA ",
+			   _regulator_get_current_limit(rdev) / 1000);
+		break;
+	}
+
+	c = rdev->constraints;
+	if (c) {
+		switch (rdev->desc->type) {
+		case REGULATOR_VOLTAGE:
+			seq_printf(s, "%5dmV %5dmV ",
+				   c->min_uV / 1000, c->max_uV / 1000);
+			break;
+		case REGULATOR_CURRENT:
+			seq_printf(s, "%5dmA %5dmA ",
+				   c->min_uA / 1000, c->max_uA / 1000);
+			break;
+		}
+	}
+
+	seq_puts(s, "\n");
+
+	list_for_each_entry(consumer, &rdev->consumer_list, list) {
+		if (consumer->dev->class == &regulator_class)
+			continue;
+
+		seq_printf(s, "%*s%-*s ",
+			   (level + 1) * 3 + 1, "",
+			   30 - (level + 1) * 3, dev_name(consumer->dev));
+
+		switch (rdev->desc->type) {
+		case REGULATOR_VOLTAGE:
+			seq_printf(s, "%29dmV %5dmV",
+				   consumer->min_uV / 1000,
+				   consumer->max_uV / 1000);
+			break;
+		case REGULATOR_CURRENT:
+			seq_printf(s, "%37dmA",
+				regulator_get_current_limit(consumer) / 1000);
+			break;
+		}
+
+		seq_puts(s, "\n");
+	}
+
+	mutex_unlock(&rdev->mutex);
+
+	list_for_each_entry(child, list, list) {
+		/* handle only non-root regulators supplied by current rdev */
+		if (!child->supply || child->supply->rdev != rdev)
+			continue;
+
+		regulator_summary_show_subtree(s, child, level + 1);
+	}
+}
+
+static int regulator_summary_show(struct seq_file *s, void *data)
+{
+	struct list_head *list = s->private;
+	struct regulator_dev *rdev;
+
+	seq_puts(s, " regulator                      use open bypass   value     min     max\n");
+	seq_puts(s, "-----------------------------------------------------------------------\n");
+
+	mutex_lock(&regulator_list_mutex);
+
+	list_for_each_entry(rdev, list, list) {
+		if (rdev->supply)
+			continue;
+
+		regulator_summary_show_subtree(s, rdev, 0);
+	}
+
+	mutex_unlock(&regulator_list_mutex);
+
+	return 0;
+}
+
+static int regulator_summary_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, regulator_summary_show, inode->i_private);
+}
+#endif
+
+static const struct file_operations regulator_summary_fops = {
+#ifdef CONFIG_DEBUG_FS
+	.open		= regulator_summary_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+#endif
+};
+
 static int __init regulator_init(void)
 {
 	int ret;

@@ -3949,6 +4067,9 @@ static int __init regulator_init(void)
 	debugfs_create_file("supply_map", 0444, debugfs_root, NULL,
 			    &supply_map_fops);
 
+	debugfs_create_file("regulator_summary", 0444, debugfs_root,
+			    &regulator_list, &regulator_summary_fops);
+
 	regulator_dummy_init();
 
 	return ret;

2.1.4

What I meant here was that we should try to output the current limit for all regulators, not just for current regulators. I've applied this as is though since it's basically OK, can you send a followup please?

Am Mittwoch, 8. April 2015, 18:38:25 schrieb Mark Brown:

ah I didn't know regulator_get_current_limit() was valid for non REGULATOR_CURRENT devices too.

Followup follows tomorrow - or today as I've just looked at the clock :-)

Heiko