diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/base/regmap/regcache.c | 791 |
1 files changed, 791 insertions, 0 deletions
diff --git a/drivers/base/regmap/regcache.c b/drivers/base/regmap/regcache.c new file mode 100644 index 000000000..7fdd702e5 --- /dev/null +++ b/drivers/base/regmap/regcache.c @@ -0,0 +1,791 @@ +// 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 = 1; + } 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->max_register = map->num_reg_defaults_raw; + + 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; + + if (WARN_ON(map->cache_type == REGCACHE_NONE)) + return -EINVAL; + + 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; + + if (WARN_ON(map->cache_type == REGCACHE_NONE)) + return -EINVAL; + + 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); +} |