--- /dev/null
+/*
+ * 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/mutex.h>
+#include <linux/debugfs.h>
+#include <linux/uaccess.h>
+#include <linux/device.h>
+#include <linux/list.h>
+
+#include "internal.h"
+
+struct regmap_debugfs_node {
+ struct regmap *map;
+ const char *name;
+ struct list_head link;
+};
+
+static struct dentry *regmap_debugfs_root;
+static LIST_HEAD(regmap_debugfs_early_list);
+static DEFINE_MUTEX(regmap_debugfs_early_lock);
+
+/* Calculate the length of a fixed format */
+static size_t regmap_calc_reg_len(int max_val, char *buf, size_t buf_size)
+{
+ snprintf(buf, buf_size, "%x", max_val);
+ return strlen(buf);
+}
+
+static ssize_t regmap_name_read_file(struct file *file,
+ char __user *user_buf, size_t count,
+ loff_t *ppos)
+{
+ struct regmap *map = file->private_data;
+ int ret;
+ char *buf;
+
+ buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ ret = snprintf(buf, PAGE_SIZE, "%s\n", map->dev->driver->name);
+ if (ret < 0) {
+ kfree(buf);
+ return ret;
+ }
+
+ ret = simple_read_from_buffer(user_buf, count, ppos, buf, ret);
+ kfree(buf);
+ return ret;
+}
+
+static const struct file_operations regmap_name_fops = {
+ .open = simple_open,
+ .read = regmap_name_read_file,
+ .llseek = default_llseek,
+};
+
+static void regmap_debugfs_free_dump_cache(struct regmap *map)
+{
+ struct regmap_debugfs_off_cache *c;
+
+ while (!list_empty(&map->debugfs_off_cache)) {
+ c = list_first_entry(&map->debugfs_off_cache,
+ struct regmap_debugfs_off_cache,
+ list);
+ list_del(&c->list);
+ kfree(c);
+ }
+}
+
+/*
+ * Work out where the start offset maps into register numbers, bearing
+ * in mind that we suppress hidden registers.
+ */
+static unsigned int regmap_debugfs_get_dump_start(struct regmap *map,
+ unsigned int base,
+ loff_t from,
+ loff_t *pos)
+{
+ struct regmap_debugfs_off_cache *c = NULL;
+ loff_t p = 0;
+ unsigned int i, ret;
+ unsigned int fpos_offset;
+ unsigned int reg_offset;
+
+ /* Suppress the cache if we're using a subrange */
+ if (base)
+ return base;
+
+ /*
+ * If we don't have a cache build one so we don't have to do a
+ * linear scan each time.
+ */
+ mutex_lock(&map->cache_lock);
+ i = base;
+ if (list_empty(&map->debugfs_off_cache)) {
+ for (; i <= map->max_register; i += map->reg_stride) {
+ /* Skip unprinted registers, closing off cache entry */
+ if (!regmap_readable(map, i) ||
+ regmap_precious(map, i)) {
+ if (c) {
+ c->max = p - 1;
+ c->max_reg = i - map->reg_stride;
+ list_add_tail(&c->list,
+ &map->debugfs_off_cache);
+ c = NULL;
+ }
+
+ continue;
+ }
+
+ /* No cache entry? Start a new one */
+ if (!c) {
+ c = kzalloc(sizeof(*c), GFP_KERNEL);
+ if (!c) {
+ regmap_debugfs_free_dump_cache(map);
+ mutex_unlock(&map->cache_lock);
+ return base;
+ }
+ c->min = p;
+ c->base_reg = i;
+ }
+
+ p += map->debugfs_tot_len;
+ }
+ }
+
+ /* Close the last entry off if we didn't scan beyond it */
+ if (c) {
+ c->max = p - 1;
+ c->max_reg = i - map->reg_stride;
+ list_add_tail(&c->list,
+ &map->debugfs_off_cache);
+ }
+
+ /*
+ * This should never happen; we return above if we fail to
+ * allocate and we should never be in this code if there are
+ * no registers at all.
+ */
+ WARN_ON(list_empty(&map->debugfs_off_cache));
+ ret = base;
+
+ /* Find the relevant block:offset */
+ list_for_each_entry(c, &map->debugfs_off_cache, list) {
+ if (from >= c->min && from <= c->max) {
+ fpos_offset = from - c->min;
+ reg_offset = fpos_offset / map->debugfs_tot_len;
+ *pos = c->min + (reg_offset * map->debugfs_tot_len);
+ mutex_unlock(&map->cache_lock);
+ return c->base_reg + (reg_offset * map->reg_stride);
+ }
+
+ *pos = c->max;
+ ret = c->max_reg;
+ }
+ mutex_unlock(&map->cache_lock);
+
+ return ret;
+}
+
+static inline void regmap_calc_tot_len(struct regmap *map,
+ void *buf, size_t count)
+{
+ /* Calculate the length of a fixed format */
+ if (!map->debugfs_tot_len) {
+ map->debugfs_reg_len = regmap_calc_reg_len(map->max_register,
+ buf, count);
+ map->debugfs_val_len = 2 * map->format.val_bytes;
+ map->debugfs_tot_len = map->debugfs_reg_len +
+ map->debugfs_val_len + 3; /* : \n */
+ }
+}
+
+static ssize_t regmap_read_debugfs(struct regmap *map, unsigned int from,
+ unsigned int to, char __user *user_buf,
+ size_t count, loff_t *ppos)
+{
+ size_t buf_pos = 0;
+ loff_t p = *ppos;
+ ssize_t ret;
+ int i;
+ char *buf;
+ unsigned int val, start_reg;
+
+ if (*ppos < 0 || !count)
+ return -EINVAL;
+
+ buf = kmalloc(count, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ regmap_calc_tot_len(map, buf, count);
+
+ /* Work out which register we're starting at */
+ start_reg = regmap_debugfs_get_dump_start(map, from, *ppos, &p);
+
+ for (i = start_reg; i <= to; i += map->reg_stride) {
+ if (!regmap_readable(map, i))
+ continue;
+
+ if (regmap_precious(map, i))
+ continue;
+
+ /* If we're in the region the user is trying to read */
+ if (p >= *ppos) {
+ /* ...but not beyond it */
+ if (buf_pos + map->debugfs_tot_len > count)
+ break;
+
+ /* Format the register */
+ snprintf(buf + buf_pos, count - buf_pos, "%.*x: ",
+ map->debugfs_reg_len, i - from);
+ buf_pos += map->debugfs_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", map->debugfs_val_len, val);
+ else
+ memset(buf + buf_pos, 'X',
+ map->debugfs_val_len);
+ buf_pos += 2 * map->format.val_bytes;
+
+ buf[buf_pos++] = '\n';
+ }
+ p += map->debugfs_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 ssize_t regmap_map_read_file(struct file *file, char __user *user_buf,
+ size_t count, loff_t *ppos)
+{
+ struct regmap *map = file->private_data;
+
+ return regmap_read_debugfs(map, 0, map->max_register, user_buf,
+ count, ppos);
+}
+
+#undef REGMAP_ALLOW_WRITE_DEBUGFS
+#ifdef REGMAP_ALLOW_WRITE_DEBUGFS
+/*
+ * This can be dangerous especially when we have clients such as
+ * PMICs, therefore don't provide any real compile time configuration option
+ * for this feature, people who want to use this will need to modify
+ * the source code directly.
+ */
+static ssize_t regmap_map_write_file(struct file *file,
+ const char __user *user_buf,
+ size_t count, loff_t *ppos)
+{
+ char buf[32];
+ size_t buf_size;
+ char *start = buf;
+ unsigned long reg, value;
+ struct regmap *map = file->private_data;
+ int ret;
+
+ buf_size = min(count, (sizeof(buf)-1));
+ if (copy_from_user(buf, user_buf, buf_size))
+ return -EFAULT;
+ buf[buf_size] = 0;
+
+ while (*start == ' ')
+ start++;
+ reg = simple_strtoul(start, &start, 16);
+ while (*start == ' ')
+ start++;
+ if (kstrtoul(start, 16, &value))
+ return -EINVAL;
+
+ /* Userspace has been fiddling around behind the kernel's back */
+ add_taint(TAINT_USER, LOCKDEP_STILL_OK);
+
+ ret = regmap_write(map, reg, value);
+ if (ret < 0)
+ return ret;
+ return buf_size;
+}
+#else
+#define regmap_map_write_file NULL
+#endif
+
+static const struct file_operations regmap_map_fops = {
+ .open = simple_open,
+ .read = regmap_map_read_file,
+ .write = regmap_map_write_file,
+ .llseek = default_llseek,
+};
+
+static ssize_t regmap_range_read_file(struct file *file, char __user *user_buf,
+ size_t count, loff_t *ppos)
+{
+ struct regmap_range_node *range = file->private_data;
+ struct regmap *map = range->map;
+
+ return regmap_read_debugfs(map, range->range_min, range->range_max,
+ user_buf, count, ppos);
+}
+
+static const struct file_operations regmap_range_fops = {
+ .open = simple_open,
+ .read = regmap_range_read_file,
+ .llseek = default_llseek,
+};
+
+static ssize_t regmap_reg_ranges_read_file(struct file *file,
+ char __user *user_buf, size_t count,
+ loff_t *ppos)
+{
+ struct regmap *map = file->private_data;
+ struct regmap_debugfs_off_cache *c;
+ loff_t p = 0;
+ size_t buf_pos = 0;
+ char *buf;
+ char *entry;
+ int ret;
+
+ if (*ppos < 0 || !count)
+ return -EINVAL;
+
+ buf = kmalloc(count, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ entry = kmalloc(PAGE_SIZE, GFP_KERNEL);
+ if (!entry) {
+ kfree(buf);
+ return -ENOMEM;
+ }
+
+ /* While we are at it, build the register dump cache
+ * now so the read() operation on the `registers' file
+ * can benefit from using the cache. We do not care
+ * about the file position information that is contained
+ * in the cache, just about the actual register blocks */
+ regmap_calc_tot_len(map, buf, count);
+ regmap_debugfs_get_dump_start(map, 0, *ppos, &p);
+
+ /* Reset file pointer as the fixed-format of the `registers'
+ * file is not compatible with the `range' file */
+ p = 0;
+ mutex_lock(&map->cache_lock);
+ list_for_each_entry(c, &map->debugfs_off_cache, list) {
+ snprintf(entry, PAGE_SIZE, "%x-%x",
+ c->base_reg, c->max_reg);
+ if (p >= *ppos) {
+ if (buf_pos + 1 + strlen(entry) > count)
+ break;
+ snprintf(buf + buf_pos, count - buf_pos,
+ "%s", entry);
+ buf_pos += strlen(entry);
+ buf[buf_pos] = '\n';
+ buf_pos++;
+ }
+ p += strlen(entry) + 1;
+ }
+ mutex_unlock(&map->cache_lock);
+
+ kfree(entry);
+ ret = buf_pos;
+
+ if (copy_to_user(user_buf, buf, buf_pos)) {
+ ret = -EFAULT;
+ goto out_buf;
+ }
+
+ *ppos += buf_pos;
+out_buf:
+ kfree(buf);
+ return ret;
+}
+
+static const struct file_operations regmap_reg_ranges_fops = {
+ .open = simple_open,
+ .read = regmap_reg_ranges_read_file,
+ .llseek = default_llseek,
+};
+
+static ssize_t regmap_access_read_file(struct file *file,
+ char __user *user_buf, size_t count,
+ loff_t *ppos)
+{
+ int reg_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;
+
+ if (*ppos < 0 || !count)
+ return -EINVAL;
+
+ buf = kmalloc(count, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ /* Calculate the length of a fixed format */
+ reg_len = regmap_calc_reg_len(map->max_register, buf, count);
+ tot_len = reg_len + 10; /* ': R W V P\n' */
+
+ for (i = 0; i <= map->max_register; i += map->reg_stride) {
+ /* Ignore registers which are neither readable nor writable */
+ if (!regmap_readable(map, i) && !regmap_writeable(map, 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: %c %c %c %c\n",
+ reg_len, i,
+ regmap_readable(map, i) ? 'y' : 'n',
+ regmap_writeable(map, i) ? 'y' : 'n',
+ regmap_volatile(map, i) ? 'y' : 'n',
+ regmap_precious(map, i) ? 'y' : 'n');
+
+ buf_pos += tot_len;
+ }
+ 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_access_fops = {
+ .open = simple_open,
+ .read = regmap_access_read_file,
+ .llseek = default_llseek,
+};
+
+void regmap_debugfs_init(struct regmap *map, const char *name)
+{
+ struct rb_node *next;
+ struct regmap_range_node *range_node;
+ const char *devname = "dummy";
+
+ /* If we don't have the debugfs root yet, postpone init */
+ if (!regmap_debugfs_root) {
+ struct regmap_debugfs_node *node;
+ node = kzalloc(sizeof(*node), GFP_KERNEL);
+ if (!node)
+ return;
+ node->map = map;
+ node->name = name;
+ mutex_lock(®map_debugfs_early_lock);
+ list_add(&node->link, ®map_debugfs_early_list);
+ mutex_unlock(®map_debugfs_early_lock);
+ return;
+ }
+
+ INIT_LIST_HEAD(&map->debugfs_off_cache);
+ mutex_init(&map->cache_lock);
+
+ if (map->dev)
+ devname = dev_name(map->dev);
+
+ if (name) {
+ map->debugfs_name = kasprintf(GFP_KERNEL, "%s-%s",
+ devname, name);
+ name = map->debugfs_name;
+ } else {
+ name = devname;
+ }
+
+ map->debugfs = debugfs_create_dir(name, regmap_debugfs_root);
+ if (!map->debugfs) {
+ dev_warn(map->dev, "Failed to create debugfs directory\n");
+ return;
+ }
+
+ debugfs_create_file("name", 0400, map->debugfs,
+ map, ®map_name_fops);
+
+ debugfs_create_file("range", 0400, map->debugfs,
+ map, ®map_reg_ranges_fops);
+
+ if (map->max_register || regmap_readable(map, 0)) {
+ umode_t registers_mode;
+
+ if (IS_ENABLED(REGMAP_ALLOW_WRITE_DEBUGFS))
+ registers_mode = 0600;
+ else
+ registers_mode = 0400;
+
+ debugfs_create_file("registers", registers_mode, map->debugfs,
+ map, ®map_map_fops);
+ debugfs_create_file("access", 0400, map->debugfs,
+ map, ®map_access_fops);
+ }
+
+ if (map->cache_type) {
+ debugfs_create_bool("cache_only", 0400, map->debugfs,
+ &map->cache_only);
+ debugfs_create_bool("cache_dirty", 0400, map->debugfs,
+ &map->cache_dirty);
+ debugfs_create_bool("cache_bypass", 0400, map->debugfs,
+ &map->cache_bypass);
+ }
+
+ next = rb_first(&map->range_tree);
+ while (next) {
+ range_node = rb_entry(next, struct regmap_range_node, node);
+
+ if (range_node->name)
+ debugfs_create_file(range_node->name, 0400,
+ map->debugfs, range_node,
+ ®map_range_fops);
+
+ next = rb_next(&range_node->node);
+ }
+
+ if (map->cache_ops && map->cache_ops->debugfs_init)
+ map->cache_ops->debugfs_init(map);
+}
+
+void regmap_debugfs_exit(struct regmap *map)
+{
+ if (map->debugfs) {
+ debugfs_remove_recursive(map->debugfs);
+ mutex_lock(&map->cache_lock);
+ regmap_debugfs_free_dump_cache(map);
+ mutex_unlock(&map->cache_lock);
+ kfree(map->debugfs_name);
+ } else {
+ struct regmap_debugfs_node *node, *tmp;
+
+ mutex_lock(®map_debugfs_early_lock);
+ list_for_each_entry_safe(node, tmp, ®map_debugfs_early_list,
+ link) {
+ if (node->map == map) {
+ list_del(&node->link);
+ kfree(node);
+ }
+ }
+ mutex_unlock(®map_debugfs_early_lock);
+ }
+}
+
+void regmap_debugfs_initcall(void)
+{
+ struct regmap_debugfs_node *node, *tmp;
+
+ regmap_debugfs_root = debugfs_create_dir("regmap", NULL);
+ if (!regmap_debugfs_root) {
+ pr_warn("regmap: Failed to create debugfs root\n");
+ return;
+ }
+
+ mutex_lock(®map_debugfs_early_lock);
+ list_for_each_entry_safe(node, tmp, ®map_debugfs_early_list, link) {
+ regmap_debugfs_init(node->map, node->name);
+ list_del(&node->link);
+ kfree(node);
+ }
+ mutex_unlock(®map_debugfs_early_lock);
+}
Code Review / kvmfornfv.git / blobdiff