/* * Register cache access API * * Copyright 2011 Wolfson Microelectronics plc * * Author: Dimitris Papastamos * * 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 #include #include #include #include #include "internal.h" static const struct regcache_ops *cache_types[] = { ®cache_indexed_ops, ®cache_rbtree_ops, ®cache_lzo_ops, }; static int regcache_hw_init(struct regmap *map) { int i, j; int ret; int count; unsigned int val; void *tmp_buf; if (!map->num_reg_defaults_raw) return -EINVAL; if (!map->reg_defaults_raw) { dev_warn(map->dev, "No cache defaults, reading back from HW\n"); tmp_buf = kmalloc(map->cache_size_raw, GFP_KERNEL); if (!tmp_buf) return -EINVAL; ret = regmap_bulk_read(map, 0, tmp_buf, map->num_reg_defaults_raw); if (ret < 0) { kfree(tmp_buf); return ret; } map->reg_defaults_raw = tmp_buf; map->cache_free = 1; } /* calculate the size of reg_defaults */ for (count = 0, i = 0; i < map->num_reg_defaults_raw; i++) { val = regcache_get_val(map->reg_defaults_raw, i, map->cache_word_size); if (!val) continue; count++; } map->reg_defaults = kmalloc(count * sizeof(struct reg_default), GFP_KERNEL); if (!map->reg_defaults) { ret = -ENOMEM; goto err_free; } /* fill the reg_defaults */ map->num_reg_defaults = count; for (i = 0, j = 0; i < map->num_reg_defaults_raw; i++) { val = regcache_get_val(map->reg_defaults_raw, i, map->cache_word_size); if (!val) continue; map->reg_defaults[j].reg = i; map->reg_defaults[j].def = val; j++; } return 0; err_free: if (map->cache_free) kfree(map->reg_defaults_raw); return ret; } int regcache_init(struct regmap *map) { int ret; int i; void *tmp_buf; if (map->cache_type == REGCACHE_NONE) { map->cache_bypass = true; return 0; } for (i = 0; i < ARRAY_SIZE(cache_types); i++) if (cache_types[i]->type == map->cache_type) break; if (i == ARRAY_SIZE(cache_types)) { dev_err(map->dev, "Could not match compress type: %d\n", map->cache_type); return -EINVAL; } map->cache = NULL; map->cache_ops = cache_types[i]; if (!map->cache_ops->read || !map->cache_ops->write || !map->cache_ops->name) return -EINVAL; /* We still need to ensure that the reg_defaults * won't vanish from under us. We'll need to make * a copy of it. */ if (map->reg_defaults) { if (!map->num_reg_defaults) return -EINVAL; tmp_buf = kmemdup(map->reg_defaults, map->num_reg_defaults * sizeof(struct reg_default), GFP_KERNEL); if (!tmp_buf) return -ENOMEM; map->reg_defaults = tmp_buf; } else if (map->num_reg_defaults_raw) { /* Some devices such as PMICs don't have cache defaults, * we cope with this by reading back the HW registers and * crafting the cache defaults by hand. */ ret = regcache_hw_init(map); if (ret < 0) return ret; } if (!map->max_register) map->max_register = map->num_reg_defaults_raw; if (map->cache_ops->init) { dev_dbg(map->dev, "Initializing %s cache\n", map->cache_ops->name); return map->cache_ops->init(map); } return 0; } void regcache_exit(struct regmap *map) { if (map->cache_type == REGCACHE_NONE) return; BUG_ON(!map->cache_ops); kfree(map->reg_defaults); if (map->cache_free) kfree(map->reg_defaults_raw); if (map->cache_ops->exit) { dev_dbg(map->dev, "Destroying %s cache\n", map->cache_ops->name); map->cache_ops->exit(map); } } /** * regcache_read: Fetch the value of a given register from the cache. * * @map: map to configure. * @reg: The register index. * @value: The value to be returned. * * Return a negative value on failure, 0 on success. */ int regcache_read(struct regmap *map, unsigned int reg, unsigned int *value) { if (map->cache_type == REGCACHE_NONE) return -ENOSYS; BUG_ON(!map->cache_ops); if (!regmap_readable(map, reg)) return -EIO; if (!regmap_volatile(map, reg)) return map->cache_ops->read(map, reg, value); return -EINVAL; } EXPORT_SYMBOL_GPL(regcache_read); /** * regcache_write: Set the value of a given register in the cache. * * @map: map to configure. * @reg: The register index. * @value: The new register value. * * Return a negative value on failure, 0 on success. */ int regcache_write(struct regmap *map, unsigned int reg, unsigned int value) { if (map->cache_type == REGCACHE_NONE) return 0; BUG_ON(!map->cache_ops); if (!regmap_writeable(map, reg)) return -EIO; if (!regmap_volatile(map, reg)) return map->cache_ops->write(map, reg, value); return 0; } EXPORT_SYMBOL_GPL(regcache_write); /** * regcache_sync: Sync the register cache with the hardware. * * @map: map to configure. * * Any registers that should not be synced should be marked as * volatile. In general drivers can choose not to use the provided * syncing functionality if they so require. * * Return a negative value on failure, 0 on success. */ int regcache_sync(struct regmap *map) { int ret = 0; unsigned int val; unsigned int i; const char *name; unsigned int bypass; BUG_ON(!map->cache_ops); mutex_lock(&map->lock); /* Remember the initial bypass state */ bypass = map->cache_bypass; dev_dbg(map->dev, "Syncing %s cache\n", map->cache_ops->name); name = map->cache_ops->name; trace_regcache_sync(map->dev, name, "start"); if (!map->cache_dirty) goto out; if (map->cache_ops->sync) { ret = map->cache_ops->sync(map); } else { for (i = 0; i < map->num_reg_defaults; i++) { ret = regcache_read(map, i, &val); if (ret < 0) goto out; map->cache_bypass = 1; ret = _regmap_write(map, i, val); map->cache_bypass = 0; if (ret < 0) goto out; dev_dbg(map->dev, "Synced register %#x, value %#x\n", map->reg_defaults[i].reg, map->reg_defaults[i].def); } } out: trace_regcache_sync(map->dev, name, "stop"); /* Restore the bypass state */ map->cache_bypass = bypass; mutex_unlock(&map->lock); return ret; } EXPORT_SYMBOL_GPL(regcache_sync); /** * regcache_cache_only: Put a register map into cache only mode * * @map: map to configure * @cache_only: flag if changes should be written to the hardware * * When a register map is marked as cache only writes to the register * map API will only update the register cache, they will not cause * any hardware changes. This is useful for allowing portions of * drivers to act as though the device were functioning as normal when * it is disabled for power saving reasons. */ void regcache_cache_only(struct regmap *map, bool enable) { mutex_lock(&map->lock); WARN_ON(map->cache_bypass && enable); map->cache_only = enable; mutex_unlock(&map->lock); } EXPORT_SYMBOL_GPL(regcache_cache_only); /** * regcache_mark_dirty: Mark the register cache as dirty * * @map: map to mark * * Mark the register cache as dirty, for example due to the device * having been powered down for suspend. If the cache is not marked * as dirty then the cache sync will be suppressed. */ void regcache_mark_dirty(struct regmap *map) { mutex_lock(&map->lock); map->cache_dirty = true; mutex_unlock(&map->lock); } EXPORT_SYMBOL_GPL(regcache_mark_dirty); /** * regcache_cache_bypass: Put a register map into cache bypass mode * * @map: map to configure * @cache_bypass: flag if changes should not be written to the hardware * * When a register map is marked with the cache bypass option, writes * to the register map API will only update the hardware and not the * the cache directly. This is useful when syncing the cache back to * the hardware. */ void regcache_cache_bypass(struct regmap *map, bool enable) { mutex_lock(&map->lock); WARN_ON(map->cache_only && enable); map->cache_bypass = enable; mutex_unlock(&map->lock); } EXPORT_SYMBOL_GPL(regcache_cache_bypass); bool regcache_set_val(void *base, unsigned int idx, unsigned int val, unsigned int word_size) { switch (word_size) { case 1: { u8 *cache = base; if (cache[idx] == val) return true; cache[idx] = val; break; } case 2: { u16 *cache = base; if (cache[idx] == val) return true; cache[idx] = val; break; } default: BUG(); } /* unreachable */ return false; } unsigned int regcache_get_val(const void *base, unsigned int idx, unsigned int word_size) { if (!base) return -EINVAL; switch (word_size) { case 1: { const u8 *cache = base; return cache[idx]; } case 2: { const u16 *cache = base; return cache[idx]; } default: BUG(); } /* unreachable */ return -1; } static int regcache_default_cmp(const void *a, const void *b) { const struct reg_default *_a = a; const struct reg_default *_b = b; return _a->reg - _b->reg; } int regcache_lookup_reg(struct regmap *map, unsigned int reg) { struct reg_default key; struct reg_default *r; key.reg = reg; key.def = 0; r = bsearch(&key, map->reg_defaults, map->num_reg_defaults, sizeof(struct reg_default), regcache_default_cmp); if (r) return r - map->reg_defaults; else return -ENOENT; } int regcache_insert_reg(struct regmap *map, unsigned int reg, unsigned int val) { void *tmp; tmp = krealloc(map->reg_defaults, (map->num_reg_defaults + 1) * sizeof(struct reg_default), GFP_KERNEL); if (!tmp) return -ENOMEM; map->reg_defaults = tmp; map->num_reg_defaults++; map->reg_defaults[map->num_reg_defaults - 1].reg = reg; map->reg_defaults[map->num_reg_defaults - 1].def = val; sort(map->reg_defaults, map->num_reg_defaults, sizeof(struct reg_default), regcache_default_cmp, NULL); return 0; }