4 files changed, 158 insertions, 0 deletions

diff --git a/drivers/base/regmap/Makefile b/drivers/base/regmap/Makefile
index f476f457129..057c13f66a6 100644
--- a/drivers/base/regmap/Makefile
+++ b/drivers/base/regmap/Makefile
@@ -1,3 +1,4 @@
 obj-$(CONFIG_REGMAP) += regmap.o
+obj-$(CONFIG_DEBUG_FS) += regmap-debugfs.o
 obj-$(CONFIG_REGMAP_I2C) += regmap-i2c.o
 obj-$(CONFIG_REGMAP_SPI) += regmap-spi.o
diff --git a/drivers/base/regmap/internal.h b/drivers/base/regmap/internal.h
index 7e61504a7ac..78f87f316a1 100644
--- a/drivers/base/regmap/internal.h
+++ b/drivers/base/regmap/internal.h
@@ -14,6 +14,7 @@
 #define _REGMAP_INTERNAL_H
 
 #include <linux/regmap.h>
+#include <linux/fs.h>
 
 struct regmap;
 
@@ -36,10 +37,24 @@ struct regmap {
 	struct regmap_format format;  /* Buffer format */
 	const struct regmap_bus *bus;
 
+#ifdef CONFIG_DEBUG_FS
+	struct dentry *debugfs;
+#endif
+
 	unsigned int max_register;
 	bool (*writeable_reg)(struct device *dev, unsigned int reg);
 	bool (*readable_reg)(struct device *dev, unsigned int reg);
 	bool (*volatile_reg)(struct device *dev, unsigned int reg);
 };
 
+#ifdef CONFIG_DEBUG_FS
+extern void regmap_debugfs_initcall(void);
+extern void regmap_debugfs_init(struct regmap *map);
+extern void regmap_debugfs_exit(struct regmap *map);
+#else
+void regmap_debugfs_initcall(void) { }
+void regmap_debugfs_init(struct regmap *map) { }
+void regmap_debugfs_exit(struct regmap *map) { }
+#endif
+
 #endif
diff --git a/drivers/base/regmap/regmap-debugfs.c b/drivers/base/regmap/regmap-debugfs.c
new file mode 100644
index 00000000000..2be8bf86825
--- /dev/null
+++ b/drivers/base/regmap/regmap-debugfs.c
@@ -0,0 +1,131 @@
+/*
+ * Register map access API - debugfs
+ *
+ * Copyright 2011 Wolfson Microelectronics plc
+ *
+ * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/debugfs.h>
+#include <linux/uaccess.h>
+
+#include "internal.h"
+
+static struct dentry *regmap_debugfs_root;
+
+static int regmap_map_open_file(struct inode *inode, struct file *file)
+{
+	file->private_data = inode->i_private;
+	return 0;
+}
+
+static ssize_t regmap_map_read_file(struct file *file, char __user *user_buf,
+				    size_t count, loff_t *ppos)
+{
+	size_t reg_len, val_len, tot_len;
+	size_t buf_pos = 0;
+	loff_t p = 0;
+	ssize_t ret;
+	int i;
+	struct regmap *map = file->private_data;
+	char *buf;
+	unsigned int val;
+
+	if (*ppos < 0 || !count)
+		return -EINVAL;
+
+	buf = kmalloc(count, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	/* Calculate the length of a fixed format  */
+	snprintf(buf, count, "%x", map->max_register);
+	reg_len = strlen(buf);
+	val_len = 2 * map->format.val_bytes;
+	tot_len = reg_len + val_len + 3;      /* : \n */
+
+	for (i = 0; i < map->max_register; i++) {
+		if (map->readable_reg &&
+		    !map->readable_reg(map->dev, i))
+			continue;
+
+		/* If we're in the region the user is trying to read */
+		if (p >= *ppos) {
+			/* ...but not beyond it */
+			if (buf_pos >= count - 1 - tot_len)
+				break;
+
+			/* Format the register */
+			snprintf(buf + buf_pos, count - buf_pos, "%.*x: ",
+				 reg_len, i);
+			buf_pos += reg_len + 2;
+
+			/* Format the value, write all X if we can't read */
+			ret = regmap_read(map, i, &val);
+			if (ret == 0)
+				snprintf(buf + buf_pos, count - buf_pos,
+					 "%.*x", val_len, val);
+			else
+				memset(buf + buf_pos, 'X', val_len);
+			buf_pos += 2 * map->format.val_bytes;
+
+			buf[buf_pos++] = '\n';
+		}
+		p += tot_len;
+	}
+
+	ret = buf_pos;
+
+	if (copy_to_user(user_buf, buf, buf_pos)) {
+		ret = -EFAULT;
+		goto out;
+	}
+
+	*ppos += buf_pos;
+
+out:
+	kfree(buf);
+	return ret;
+}
+
+static const struct file_operations regmap_map_fops = {
+	.open = regmap_map_open_file,
+	.read = regmap_map_read_file,
+	.llseek = default_llseek,
+};
+
+
+void regmap_debugfs_init(struct regmap *map)
+{
+	map->debugfs = debugfs_create_dir(dev_name(map->dev),
+					  regmap_debugfs_root);
+	if (!map->debugfs) {
+		dev_warn(map->dev, "Failed to create debugfs directory\n");
+		return;
+	}
+
+	if (map->max_register)
+		debugfs_create_file("registers", 0400, map->debugfs,
+				    map, &regmap_map_fops);
+}
+
+void regmap_debugfs_exit(struct regmap *map)
+{
+	debugfs_remove_recursive(map->debugfs);
+}
+
+void regmap_debugfs_initcall(void)
+{
+	regmap_debugfs_root = debugfs_create_dir("regmap", NULL);
+	if (!regmap_debugfs_root) {
+		pr_warn("regmap: Failed to create debugfs root\n");
+		return;
+	}
+}
diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index f51efeb091c..a3eaef6552c 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -156,6 +156,8 @@ struct regmap *regmap_init(struct device *dev,
 		goto err_bus;
 	}
 
+	regmap_debugfs_init(map);
+
 	return map;
 
 err_bus:
@@ -172,6 +174,7 @@ EXPORT_SYMBOL_GPL(regmap_init);
  */
 void regmap_exit(struct regmap *map)
 {
+	regmap_debugfs_exit(map);
 	kfree(map->work_buf);
 	module_put(map->bus->owner);
 	kfree(map);
@@ -472,3 +475,11 @@ out:
 	return ret;
 }
 EXPORT_SYMBOL_GPL(regmap_update_bits);
+
+static int __init regmap_initcall(void)
+{
+	regmap_debugfs_initcall();
+
+	return 0;
+}
+postcore_initcall(regmap_initcall);