regulator: debug-regulator: add regulator suspend logging support

Add support to print a list of the regulators found to be
enabled when entering suspend into the kernel log.  This is
useful for identifying which regulator consumers are not voting
as expected during system suspend and resume.

Change-Id: I6089871d7a5945d75fec40fdfe4787efafa1aaa0
Signed-off-by: David Collins <collinsd@codeaurora.org>

drivers/regulator/debug-regulator.c

@@ -3,8 +3,6 @@
  * Copyright (c) 2020, The Linux Foundation. All rights reserved.
  */
 
-#define pr_fmt(fmt) "%s: " fmt, __func__
-
 #include <linux/bitops.h>
 #include <linux/debugfs.h>
 #include <linux/device.h>
@@ -17,10 +15,13 @@
 #include <linux/slab.h>
 #include <linux/string.h>
 #include <linux/regulator/consumer.h>
+#include <linux/regulator/coupler.h>
 #include <linux/regulator/driver.h>
 #include <linux/regulator/machine.h>
 #include <linux/regulator/debug-regulator.h>
 
+#include <trace/events/power.h>
+
 #include "internal.h"
 
 struct debug_regulator {
@@ -44,9 +45,10 @@ static const char *rdev_name(struct regulator_dev *rdev)
 }
 
 #define dreg_err(dreg, fmt, ...)					\
-	pr_err("%s: " fmt, rdev_name((dreg)->rdev), ##__VA_ARGS__)
+	pr_err("%s: %s: " fmt, __func__, rdev_name((dreg)->rdev), ##__VA_ARGS__)
 #define dreg_dbg(dreg, fmt, ...)					\
-	pr_debug("%s: " fmt, rdev_name((dreg)->rdev), ##__VA_ARGS__)
+	pr_debug("%s: %s: " fmt, __func__, rdev_name((dreg)->rdev),	\
+		##__VA_ARGS__)
 
 static struct regulator *reg_debug_get_consumer(struct debug_regulator *dreg)
 {
@@ -365,7 +367,7 @@ static struct debug_regulator *regulator_debug_add(struct device *dev,
 	mode_t mode;
 
 	if (!dev || !rdev) {
-		pr_err("dev or rdev is NULL\n");
+		pr_err("%s: dev or rdev is NULL\n", __func__);
 		return ERR_PTR(-EINVAL);
 	}
 
@@ -468,7 +470,7 @@ void regulator_debug_unregister(struct regulator_dev *rdev)
 	struct debug_regulator *dreg, *temp;
 
 	if (IS_ERR_OR_NULL(rdev)) {
-		pr_err("invalid regulator device pointer\n");
+		pr_err("%s: invalid regulator device pointer\n", __func__);
 		return;
 	}
 
@@ -575,7 +577,7 @@ void devm_regulator_debug_unregister(struct regulator_dev *rdev)
 	struct debug_regulator *dreg, *temp;
 
 	if (IS_ERR_OR_NULL(rdev)) {
-		pr_err("invalid regulator device pointer\n");
+		pr_err("%s: invalid regulator device pointer\n", __func__);
 		return;
 	}
 
@@ -589,5 +591,146 @@ void devm_regulator_debug_unregister(struct regulator_dev *rdev)
 }
 EXPORT_SYMBOL(devm_regulator_debug_unregister);
 
+static int _regulator_is_enabled(struct regulator_dev *rdev)
+{
+	if (rdev->ena_pin)
+		return rdev->ena_gpio_state;
+
+	if (!rdev->desc->ops->is_enabled)
+		return 1;
+
+	return rdev->desc->ops->is_enabled(rdev);
+}
+
+static void regulator_debug_print_enabled(struct regulator_dev *rdev)
+{
+	struct regulator *reg;
+	const char *supply_name;
+	int mode = -EPERM;
+	int uV = -EPERM;
+
+	if (_regulator_is_enabled(rdev) <= 0)
+		return;
+
+	uV = regulator_get_voltage_rdev(rdev);
+
+	if (rdev->desc->ops->get_mode)
+		mode = rdev->desc->ops->get_mode(rdev);
+
+	if (uV != -EPERM && mode != -EPERM)
+		pr_info("%s[%u] %d uV, mode=%d\n",
+			rdev_name(rdev), rdev->use_count, uV, mode);
+	else if (uV != -EPERM)
+		pr_info("%s[%u] %d uV\n",
+			rdev_name(rdev), rdev->use_count, uV);
+	else if (mode != -EPERM)
+		pr_info("%s[%u], mode=%d\n",
+			rdev_name(rdev), rdev->use_count, mode);
+	else
+		pr_info("%s[%u]\n", rdev_name(rdev), rdev->use_count);
+
+	/* Print a header if there are consumers. */
+	if (rdev->open_count)
+		pr_info("  %-32s EN    Min_uV   Max_uV  load_uA\n",
+			"Device-Supply");
+
+	list_for_each_entry(reg, &rdev->consumer_list, list) {
+		if (reg->supply_name)
+			supply_name = reg->supply_name;
+		else
+			supply_name = "(null)-(null)";
+
+		pr_info("  %-32s %d   %8d %8d %8d\n", supply_name,
+			reg->enable_count,
+			reg->voltage[PM_SUSPEND_ON].min_uV,
+			reg->voltage[PM_SUSPEND_ON].max_uV,
+			reg->uA_load);
+	}
+}
+
+static void regulator_debug_suspend_trace_probe(void *unused,
+					const char *action, int val, bool start)
+{
+	struct debug_regulator *dreg;
+
+	if (start && val > 0 && !strcmp("machine_suspend", action)) {
+		pr_info("Enabled regulators:\n");
+		list_for_each_entry(dreg, &debug_reg_list, list)
+			regulator_debug_print_enabled(dreg->rdev);
+	}
+}
+
+static bool debug_suspend;
+static struct dentry *regulator_suspend_debugfs;
+
+static int reg_debug_suspend_enable_get(void *data, u64 *val)
+{
+	*val = debug_suspend;
+
+	return 0;
+}
+
+static int reg_debug_suspend_enable_set(void *data, u64 val)
+{
+	int ret;
+
+	val = !!val;
+	if (val == debug_suspend)
+		return 0;
+
+	if (val)
+		ret = register_trace_suspend_resume(
+				regulator_debug_suspend_trace_probe, NULL);
+	else
+		ret = unregister_trace_suspend_resume(
+				regulator_debug_suspend_trace_probe, NULL);
+	if (ret) {
+		pr_err("%s: Failed to %sregister suspend trace callback, ret=%d\n",
+			__func__, val ? "" : "un", ret);
+		return ret;
+	}
+	debug_suspend = val;
+
+	return 0;
+}
+DEFINE_DEBUGFS_ATTRIBUTE(reg_debug_suspend_enable_fops,
+	reg_debug_suspend_enable_get, reg_debug_suspend_enable_set, "%llu\n");
+
+static int __init regulator_debug_init(void)
+{
+	static struct dentry *dir;
+	int ret;
+
+	dir = debugfs_lookup("regulator", NULL);
+	if (IS_ERR_OR_NULL(dir)) {
+		ret = PTR_ERR(dir);
+		pr_err("%s: unable to find root regulator debugfs directory, ret=%d\n",
+			__func__, ret);
+		return 0;
+	}
+
+	regulator_suspend_debugfs = debugfs_create_file_unsafe("debug_suspend",
+						0644, dir, NULL,
+						&reg_debug_suspend_enable_fops);
+	dput(dir);
+	if (IS_ERR(regulator_suspend_debugfs)) {
+		ret = PTR_ERR(regulator_suspend_debugfs);
+		pr_err("%s: unable to create regulator debug_suspend debugfs directory, ret=%d\n",
+			__func__, ret);
+	}
+
+	return 0;
+}
+module_init(regulator_debug_init);
+
+static void __exit regulator_debug_exit(void)
+{
+	debugfs_remove(regulator_suspend_debugfs);
+	if (debug_suspend)
+		unregister_trace_suspend_resume(
+				regulator_debug_suspend_trace_probe, NULL);
+}
+module_exit(regulator_debug_exit);
+
 MODULE_DESCRIPTION("Regulator debug control library");
 MODULE_LICENSE("GPL v2");