From adaac459759db4a1fd35baddbe47bac700095496 Mon Sep 17 00:00:00 2001 From: Markus Pargmann Date: Sun, 30 Aug 2015 09:33:53 +0200 Subject: [PATCH] regmap: Introduce max_raw_read/write for regmap_bulk_read/write There are some buses which have a limit on the maximum number of bytes that can be send/received. An example for this is I2C_FUNC_SMBUS_I2C_BLOCK which does not support any reads/writes of more than 32 bytes. The regmap_bulk operations should still be able to utilize the full 32 bytes in this case. Signed-off-by: Markus Pargmann Signed-off-by: Mark Brown --- drivers/base/regmap/internal.h | 4 ++ drivers/base/regmap/regmap.c | 85 ++++++++++++++++++++++++++++------ include/linux/regmap.h | 4 ++ 3 files changed, 78 insertions(+), 15 deletions(-) diff --git a/drivers/base/regmap/internal.h b/drivers/base/regmap/internal.h index d744ae3926dd..fc554e357c5d 100644 --- a/drivers/base/regmap/internal.h +++ b/drivers/base/regmap/internal.h @@ -146,6 +146,10 @@ struct regmap { /* if set, the device supports multi write mode */ bool can_multi_write; + /* if set, raw reads/writes are limited to this size */ + size_t max_raw_read; + size_t max_raw_write; + struct rb_root range_tree; void *selector_work_buf; /* Scratch buffer used for selector */ }; diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c index a6b6f7ee87ee..7cbe42680877 100644 --- a/drivers/base/regmap/regmap.c +++ b/drivers/base/regmap/regmap.c @@ -579,6 +579,8 @@ struct regmap *regmap_init(struct device *dev, map->use_single_read = config->use_single_rw || !bus || !bus->read; map->use_single_write = config->use_single_rw || !bus || !bus->write; map->can_multi_write = config->can_multi_write && bus && bus->write; + map->max_raw_read = bus->max_raw_read; + map->max_raw_write = bus->max_raw_write; map->dev = dev; map->bus = bus; map->bus_context = bus_context; @@ -1674,6 +1676,7 @@ int regmap_bulk_write(struct regmap *map, unsigned int reg, const void *val, { int ret = 0, i; size_t val_bytes = map->format.val_bytes; + size_t total_size = val_bytes * val_count; if (map->bus && !map->format.parse_inplace) return -EINVAL; @@ -1722,16 +1725,37 @@ int regmap_bulk_write(struct regmap *map, unsigned int reg, const void *val, } out: map->unlock(map->lock_arg); - } else if (map->use_single_write) { + } else if (map->use_single_write || + (map->max_raw_write && map->max_raw_write < total_size)) { + int chunk_stride = map->reg_stride; + size_t chunk_size = val_bytes; + size_t chunk_count = val_count; + + if (!map->use_single_write) { + chunk_size = map->max_raw_write; + if (chunk_size % val_bytes) + chunk_size -= chunk_size % val_bytes; + chunk_count = total_size / chunk_size; + chunk_stride *= chunk_size / val_bytes; + } + map->lock(map->lock_arg); - for (i = 0; i < val_count; i++) { + /* Write as many bytes as possible with chunk_size */ + for (i = 0; i < chunk_count; i++) { ret = _regmap_raw_write(map, - reg + (i * map->reg_stride), - val + (i * val_bytes), - val_bytes); + reg + (i * chunk_stride), + val + (i * chunk_size), + chunk_size); if (ret) break; } + + /* Write remaining bytes */ + if (!ret && chunk_size * i < total_size) { + ret = _regmap_raw_write(map, reg + (i * chunk_stride), + val + (i * chunk_size), + total_size - i * chunk_size); + } map->unlock(map->lock_arg); } else { void *wval; @@ -2319,20 +2343,51 @@ int regmap_bulk_read(struct regmap *map, unsigned int reg, void *val, * Some devices does not support bulk read, for * them we have a series of single read operations. */ - if (map->use_single_read) { - for (i = 0; i < val_count; i++) { - ret = regmap_raw_read(map, - reg + (i * map->reg_stride), - val + (i * val_bytes), - val_bytes); - if (ret != 0) - return ret; - } - } else { + size_t total_size = val_bytes * val_count; + + if (!map->use_single_read && + (!map->max_raw_read || map->max_raw_read > total_size)) { ret = regmap_raw_read(map, reg, val, val_bytes * val_count); if (ret != 0) return ret; + } else { + /* + * Some devices do not support bulk read or do not + * support large bulk reads, for them we have a series + * of read operations. + */ + int chunk_stride = map->reg_stride; + size_t chunk_size = val_bytes; + size_t chunk_count = val_count; + + if (!map->use_single_read) { + chunk_size = map->max_raw_read; + if (chunk_size % val_bytes) + chunk_size -= chunk_size % val_bytes; + chunk_count = total_size / chunk_size; + chunk_stride *= chunk_size / val_bytes; + } + + /* Read bytes that fit into a multiple of chunk_size */ + for (i = 0; i < chunk_count; i++) { + ret = regmap_raw_read(map, + reg + (i * chunk_stride), + val + (i * chunk_size), + chunk_size); + if (ret != 0) + return ret; + } + + /* Read remaining bytes */ + if (chunk_size * i < total_size) { + ret = regmap_raw_read(map, + reg + (i * chunk_stride), + val + (i * chunk_size), + total_size - i * chunk_size); + if (ret != 0) + return ret; + } } for (i = 0; i < val_count * val_bytes; i += val_bytes) diff --git a/include/linux/regmap.h b/include/linux/regmap.h index 73fc34d0c4c2..327b8f291d3f 100644 --- a/include/linux/regmap.h +++ b/include/linux/regmap.h @@ -311,6 +311,8 @@ typedef void (*regmap_hw_free_context)(void *context); * @val_format_endian_default: Default endianness for formatted register * values. Used when the regmap_config specifies DEFAULT. If this is * DEFAULT, BIG is assumed. + * @max_raw_read: Max raw read size that can be used on the bus. + * @max_raw_write: Max raw write size that can be used on the bus. */ struct regmap_bus { bool fast_io; @@ -325,6 +327,8 @@ struct regmap_bus { u8 read_flag_mask; enum regmap_endian reg_format_endian_default; enum regmap_endian val_format_endian_default; + size_t max_raw_read; + size_t max_raw_write; }; struct regmap *regmap_init(struct device *dev,