| // SPDX-License-Identifier: GPL-2.0 |
| // |
| // Register cache access API |
| // |
| // Copyright 2011 Wolfson Microelectronics plc |
| // |
| // Author: Dimitris Papastamos <dp@opensource.wolfsonmicro.com> |
| |
| #include <linux/bsearch.h> |
| #include <linux/device.h> |
| #include <linux/export.h> |
| #include <linux/slab.h> |
| #include <linux/sort.h> |
| |
| #include "trace.h" |
| #include "internal.h" |
| |
| static const struct regcache_ops *cache_types[] = { |
| ®cache_rbtree_ops, |
| #if IS_ENABLED(CONFIG_REGCACHE_COMPRESSED) |
| ®cache_lzo_ops, |
| #endif |
| ®cache_flat_ops, |
| }; |
| |
| static int regcache_hw_init(struct regmap *map) |
| { |
| int i, j; |
| int ret; |
| int count; |
| unsigned int reg, val; |
| void *tmp_buf; |
| |
| if (!map->num_reg_defaults_raw) |
| return -EINVAL; |
| |
| /* calculate the size of reg_defaults */ |
| for (count = 0, i = 0; i < map->num_reg_defaults_raw; i++) |
| if (regmap_readable(map, i * map->reg_stride) && |
| !regmap_volatile(map, i * map->reg_stride)) |
| count++; |
| |
| /* all registers are unreadable or volatile, so just bypass */ |
| if (!count) { |
| map->cache_bypass = true; |
| return 0; |
| } |
| |
| map->num_reg_defaults = count; |
| map->reg_defaults = kmalloc_array(count, sizeof(struct reg_default), |
| GFP_KERNEL); |
| if (!map->reg_defaults) |
| return -ENOMEM; |
| |
| if (!map->reg_defaults_raw) { |
| bool cache_bypass = map->cache_bypass; |
| dev_warn(map->dev, "No cache defaults, reading back from HW\n"); |
| |
| /* Bypass the cache access till data read from HW */ |
| map->cache_bypass = true; |
| tmp_buf = kmalloc(map->cache_size_raw, GFP_KERNEL); |
| if (!tmp_buf) { |
| ret = -ENOMEM; |
| goto err_free; |
| } |
| ret = regmap_raw_read(map, 0, tmp_buf, |
| map->cache_size_raw); |
| map->cache_bypass = cache_bypass; |
| if (ret == 0) { |
| map->reg_defaults_raw = tmp_buf; |
| map->cache_free = true; |
| } else { |
| kfree(tmp_buf); |
| } |
| } |
| |
| /* fill the reg_defaults */ |
| for (i = 0, j = 0; i < map->num_reg_defaults_raw; i++) { |
| reg = i * map->reg_stride; |
| |
| if (!regmap_readable(map, reg)) |
| continue; |
| |
| if (regmap_volatile(map, reg)) |
| continue; |
| |
| if (map->reg_defaults_raw) { |
| val = regcache_get_val(map, map->reg_defaults_raw, i); |
| } else { |
| bool cache_bypass = map->cache_bypass; |
| |
| map->cache_bypass = true; |
| ret = regmap_read(map, reg, &val); |
| map->cache_bypass = cache_bypass; |
| if (ret != 0) { |
| dev_err(map->dev, "Failed to read %d: %d\n", |
| reg, ret); |
| goto err_free; |
| } |
| } |
| |
| map->reg_defaults[j].reg = reg; |
| map->reg_defaults[j].def = val; |
| j++; |
| } |
| |
| return 0; |
| |
| err_free: |
| kfree(map->reg_defaults); |
| |
| return ret; |
| } |
| |
| int regcache_init(struct regmap *map, const struct regmap_config *config) |
| { |
| int ret; |
| int i; |
| void *tmp_buf; |
| |
| if (map->cache_type == REGCACHE_NONE) { |
| if (config->reg_defaults || config->num_reg_defaults_raw) |
| dev_warn(map->dev, |
| "No cache used with register defaults set!\n"); |
| |
| map->cache_bypass = true; |
| return 0; |
| } |
| |
| if (config->reg_defaults && !config->num_reg_defaults) { |
| dev_err(map->dev, |
| "Register defaults are set without the number!\n"); |
| return -EINVAL; |
| } |
| |
| for (i = 0; i < config->num_reg_defaults; i++) |
| if (config->reg_defaults[i].reg % map->reg_stride) |
| return -EINVAL; |
| |
| 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->num_reg_defaults = config->num_reg_defaults; |
| map->num_reg_defaults_raw = config->num_reg_defaults_raw; |
| map->reg_defaults_raw = config->reg_defaults_raw; |
| map->cache_word_size = DIV_ROUND_UP(config->val_bits, 8); |
| map->cache_size_raw = map->cache_word_size * config->num_reg_defaults_raw; |
| |
| 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 (config->reg_defaults) { |
| tmp_buf = kmemdup(config->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->cache_bypass) |
| return 0; |
| } |
| |
| if (!map->max_register && map->num_reg_defaults_raw) |
| map->max_register = (map->num_reg_defaults_raw - 1) * map->reg_stride; |
| |
| if (map->cache_ops->init) { |
| dev_dbg(map->dev, "Initializing %s cache\n", |
| map->cache_ops->name); |
| ret = map->cache_ops->init(map); |
| if (ret) |
| goto err_free; |
| } |
| return 0; |
| |
| err_free: |
| kfree(map->reg_defaults); |
| if (map->cache_free) |
| kfree(map->reg_defaults_raw); |
| |
| return ret; |
| } |
| |
| 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) |
| { |
| int ret; |
| |
| if (map->cache_type == REGCACHE_NONE) |
| return -ENOSYS; |
| |
| BUG_ON(!map->cache_ops); |
| |
| if (!regmap_volatile(map, reg)) { |
| ret = map->cache_ops->read(map, reg, value); |
| |
| if (ret == 0) |
| trace_regmap_reg_read_cache(map, reg, *value); |
| |
| return ret; |
| } |
| |
| return -EINVAL; |
| } |
| |
| /** |
| * 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_volatile(map, reg)) |
| return map->cache_ops->write(map, reg, value); |
| |
| return 0; |
| } |
| |
| static bool regcache_reg_needs_sync(struct regmap *map, unsigned int reg, |
| unsigned int val) |
| { |
| int ret; |
| |
| /* If we don't know the chip just got reset, then sync everything. */ |
| if (!map->no_sync_defaults) |
| return true; |
| |
| /* Is this the hardware default? If so skip. */ |
| ret = regcache_lookup_reg(map, reg); |
| if (ret >= 0 && val == map->reg_defaults[ret].def) |
| return false; |
| return true; |
| } |
| |
| static int regcache_default_sync(struct regmap *map, unsigned int min, |
| unsigned int max) |
| { |
| unsigned int reg; |
| |
| for (reg = min; reg <= max; reg += map->reg_stride) { |
| unsigned int val; |
| int ret; |
| |
| if (regmap_volatile(map, reg) || |
| !regmap_writeable(map, reg)) |
| continue; |
| |
| ret = regcache_read(map, reg, &val); |
| if (ret) |
| return ret; |
| |
| if (!regcache_reg_needs_sync(map, reg, val)) |
| continue; |
| |
| map->cache_bypass = true; |
| ret = _regmap_write(map, reg, val); |
| map->cache_bypass = false; |
| if (ret) { |
| dev_err(map->dev, "Unable to sync register %#x. %d\n", |
| reg, ret); |
| return ret; |
| } |
| dev_dbg(map->dev, "Synced register %#x, value %#x\n", reg, val); |
| } |
| |
| return 0; |
| } |
| |
| /** |
| * 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 i; |
| const char *name; |
| bool bypass; |
| |
| BUG_ON(!map->cache_ops); |
| |
| map->lock(map->lock_arg); |
| /* 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, name, "start"); |
| |
| if (!map->cache_dirty) |
| goto out; |
| |
| map->async = true; |
| |
| /* Apply any patch first */ |
| map->cache_bypass = true; |
| for (i = 0; i < map->patch_regs; i++) { |
| ret = _regmap_write(map, map->patch[i].reg, map->patch[i].def); |
| if (ret != 0) { |
| dev_err(map->dev, "Failed to write %x = %x: %d\n", |
| map->patch[i].reg, map->patch[i].def, ret); |
| goto out; |
| } |
| } |
| map->cache_bypass = false; |
| |
| if (map->cache_ops->sync) |
| ret = map->cache_ops->sync(map, 0, map->max_register); |
| else |
| ret = regcache_default_sync(map, 0, map->max_register); |
| |
| if (ret == 0) |
| map->cache_dirty = false; |
| |
| out: |
| /* Restore the bypass state */ |
| map->async = false; |
| map->cache_bypass = bypass; |
| map->no_sync_defaults = false; |
| map->unlock(map->lock_arg); |
| |
| regmap_async_complete(map); |
| |
| trace_regcache_sync(map, name, "stop"); |
| |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(regcache_sync); |
| |
| /** |
| * regcache_sync_region - Sync part of the register cache with the hardware. |
| * |
| * @map: map to sync. |
| * @min: first register to sync |
| * @max: last register to sync |
| * |
| * Write all non-default register values in the specified region to |
| * the hardware. |
| * |
| * Return a negative value on failure, 0 on success. |
| */ |
| int regcache_sync_region(struct regmap *map, unsigned int min, |
| unsigned int max) |
| { |
| int ret = 0; |
| const char *name; |
| bool bypass; |
| |
| BUG_ON(!map->cache_ops); |
| |
| map->lock(map->lock_arg); |
| |
| /* Remember the initial bypass state */ |
| bypass = map->cache_bypass; |
| |
| name = map->cache_ops->name; |
| dev_dbg(map->dev, "Syncing %s cache from %d-%d\n", name, min, max); |
| |
| trace_regcache_sync(map, name, "start region"); |
| |
| if (!map->cache_dirty) |
| goto out; |
| |
| map->async = true; |
| |
| if (map->cache_ops->sync) |
| ret = map->cache_ops->sync(map, min, max); |
| else |
| ret = regcache_default_sync(map, min, max); |
| |
| out: |
| /* Restore the bypass state */ |
| map->cache_bypass = bypass; |
| map->async = false; |
| map->no_sync_defaults = false; |
| map->unlock(map->lock_arg); |
| |
| regmap_async_complete(map); |
| |
| trace_regcache_sync(map, name, "stop region"); |
| |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(regcache_sync_region); |
| |
| /** |
| * regcache_drop_region - Discard part of the register cache |
| * |
| * @map: map to operate on |
| * @min: first register to discard |
| * @max: last register to discard |
| * |
| * Discard part of the register cache. |
| * |
| * Return a negative value on failure, 0 on success. |
| */ |
| int regcache_drop_region(struct regmap *map, unsigned int min, |
| unsigned int max) |
| { |
| int ret = 0; |
| |
| if (!map->cache_ops || !map->cache_ops->drop) |
| return -EINVAL; |
| |
| map->lock(map->lock_arg); |
| |
| trace_regcache_drop_region(map, min, max); |
| |
| ret = map->cache_ops->drop(map, min, max); |
| |
| map->unlock(map->lock_arg); |
| |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(regcache_drop_region); |
| |
| /** |
| * regcache_cache_only - Put a register map into cache only mode |
| * |
| * @map: map to configure |
| * @enable: 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) |
| { |
| map->lock(map->lock_arg); |
| WARN_ON(map->cache_bypass && enable); |
| map->cache_only = enable; |
| trace_regmap_cache_only(map, enable); |
| map->unlock(map->lock_arg); |
| } |
| EXPORT_SYMBOL_GPL(regcache_cache_only); |
| |
| /** |
| * regcache_mark_dirty - Indicate that HW registers were reset to default values |
| * |
| * @map: map to mark |
| * |
| * Inform regcache that the device has been powered down or reset, so that |
| * on resume, regcache_sync() knows to write out all non-default values |
| * stored in the cache. |
| * |
| * If this function is not called, regcache_sync() will assume that |
| * the hardware state still matches the cache state, modulo any writes that |
| * happened when cache_only was true. |
| */ |
| void regcache_mark_dirty(struct regmap *map) |
| { |
| map->lock(map->lock_arg); |
| map->cache_dirty = true; |
| map->no_sync_defaults = true; |
| map->unlock(map->lock_arg); |
| } |
| EXPORT_SYMBOL_GPL(regcache_mark_dirty); |
| |
| /** |
| * regcache_cache_bypass - Put a register map into cache bypass mode |
| * |
| * @map: map to configure |
| * @enable: flag if changes should not be written to the cache |
| * |
| * 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) |
| { |
| map->lock(map->lock_arg); |
| WARN_ON(map->cache_only && enable); |
| map->cache_bypass = enable; |
| trace_regmap_cache_bypass(map, enable); |
| map->unlock(map->lock_arg); |
| } |
| EXPORT_SYMBOL_GPL(regcache_cache_bypass); |
| |
| bool regcache_set_val(struct regmap *map, void *base, unsigned int idx, |
| unsigned int val) |
| { |
| if (regcache_get_val(map, base, idx) == val) |
| return true; |
| |
| /* Use device native format if possible */ |
| if (map->format.format_val) { |
| map->format.format_val(base + (map->cache_word_size * idx), |
| val, 0); |
| return false; |
| } |
| |
| switch (map->cache_word_size) { |
| case 1: { |
| u8 *cache = base; |
| |
| cache[idx] = val; |
| break; |
| } |
| case 2: { |
| u16 *cache = base; |
| |
| cache[idx] = val; |
| break; |
| } |
| case 4: { |
| u32 *cache = base; |
| |
| cache[idx] = val; |
| break; |
| } |
| #ifdef CONFIG_64BIT |
| case 8: { |
| u64 *cache = base; |
| |
| cache[idx] = val; |
| break; |
| } |
| #endif |
| default: |
| BUG(); |
| } |
| return false; |
| } |
| |
| unsigned int regcache_get_val(struct regmap *map, const void *base, |
| unsigned int idx) |
| { |
| if (!base) |
| return -EINVAL; |
| |
| /* Use device native format if possible */ |
| if (map->format.parse_val) |
| return map->format.parse_val(regcache_get_val_addr(map, base, |
| idx)); |
| |
| switch (map->cache_word_size) { |
| case 1: { |
| const u8 *cache = base; |
| |
| return cache[idx]; |
| } |
| case 2: { |
| const u16 *cache = base; |
| |
| return cache[idx]; |
| } |
| case 4: { |
| const u32 *cache = base; |
| |
| return cache[idx]; |
| } |
| #ifdef CONFIG_64BIT |
| case 8: { |
| const u64 *cache = base; |
| |
| return cache[idx]; |
| } |
| #endif |
| 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; |
| } |
| |
| static bool regcache_reg_present(unsigned long *cache_present, unsigned int idx) |
| { |
| if (!cache_present) |
| return true; |
| |
| return test_bit(idx, cache_present); |
| } |
| |
| static int regcache_sync_block_single(struct regmap *map, void *block, |
| unsigned long *cache_present, |
| unsigned int block_base, |
| unsigned int start, unsigned int end) |
| { |
| unsigned int i, regtmp, val; |
| int ret; |
| |
| for (i = start; i < end; i++) { |
| regtmp = block_base + (i * map->reg_stride); |
| |
| if (!regcache_reg_present(cache_present, i) || |
| !regmap_writeable(map, regtmp)) |
| continue; |
| |
| val = regcache_get_val(map, block, i); |
| if (!regcache_reg_needs_sync(map, regtmp, val)) |
| continue; |
| |
| map->cache_bypass = true; |
| |
| ret = _regmap_write(map, regtmp, val); |
| |
| map->cache_bypass = false; |
| if (ret != 0) { |
| dev_err(map->dev, "Unable to sync register %#x. %d\n", |
| regtmp, ret); |
| return ret; |
| } |
| dev_dbg(map->dev, "Synced register %#x, value %#x\n", |
| regtmp, val); |
| } |
| |
| return 0; |
| } |
| |
| static int regcache_sync_block_raw_flush(struct regmap *map, const void **data, |
| unsigned int base, unsigned int cur) |
| { |
| size_t val_bytes = map->format.val_bytes; |
| int ret, count; |
| |
| if (*data == NULL) |
| return 0; |
| |
| count = (cur - base) / map->reg_stride; |
| |
| dev_dbg(map->dev, "Writing %zu bytes for %d registers from 0x%x-0x%x\n", |
| count * val_bytes, count, base, cur - map->reg_stride); |
| |
| map->cache_bypass = true; |
| |
| ret = _regmap_raw_write(map, base, *data, count * val_bytes, false); |
| if (ret) |
| dev_err(map->dev, "Unable to sync registers %#x-%#x. %d\n", |
| base, cur - map->reg_stride, ret); |
| |
| map->cache_bypass = false; |
| |
| *data = NULL; |
| |
| return ret; |
| } |
| |
| static int regcache_sync_block_raw(struct regmap *map, void *block, |
| unsigned long *cache_present, |
| unsigned int block_base, unsigned int start, |
| unsigned int end) |
| { |
| unsigned int i, val; |
| unsigned int regtmp = 0; |
| unsigned int base = 0; |
| const void *data = NULL; |
| int ret; |
| |
| for (i = start; i < end; i++) { |
| regtmp = block_base + (i * map->reg_stride); |
| |
| if (!regcache_reg_present(cache_present, i) || |
| !regmap_writeable(map, regtmp)) { |
| ret = regcache_sync_block_raw_flush(map, &data, |
| base, regtmp); |
| if (ret != 0) |
| return ret; |
| continue; |
| } |
| |
| val = regcache_get_val(map, block, i); |
| if (!regcache_reg_needs_sync(map, regtmp, val)) { |
| ret = regcache_sync_block_raw_flush(map, &data, |
| base, regtmp); |
| if (ret != 0) |
| return ret; |
| continue; |
| } |
| |
| if (!data) { |
| data = regcache_get_val_addr(map, block, i); |
| base = regtmp; |
| } |
| } |
| |
| return regcache_sync_block_raw_flush(map, &data, base, regtmp + |
| map->reg_stride); |
| } |
| |
| int regcache_sync_block(struct regmap *map, void *block, |
| unsigned long *cache_present, |
| unsigned int block_base, unsigned int start, |
| unsigned int end) |
| { |
| if (regmap_can_raw_write(map) && !map->use_single_write) |
| return regcache_sync_block_raw(map, block, cache_present, |
| block_base, start, end); |
| else |
| return regcache_sync_block_single(map, block, cache_present, |
| block_base, start, end); |
| } |