597 lines
14 KiB
C
597 lines
14 KiB
C
/*
|
|
* 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);
|
|
}
|