diff options
Diffstat (limited to 'drivers/base/regmap/regmap-debugfs.c')
| -rw-r--r-- | drivers/base/regmap/regmap-debugfs.c | 597 |
1 files changed, 597 insertions, 0 deletions
diff --git a/drivers/base/regmap/regmap-debugfs.c b/drivers/base/regmap/regmap-debugfs.c new file mode 100644 index 000000000..5799a0b9e --- /dev/null +++ b/drivers/base/regmap/regmap-debugfs.c @@ -0,0 +1,597 @@ +/* + * 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); +} |