diff options
Diffstat (limited to 'drivers/base/regmap/regmap-spi.c')
| -rw-r--r-- | drivers/base/regmap/regmap-spi.c | 168 |
1 files changed, 168 insertions, 0 deletions
diff --git a/drivers/base/regmap/regmap-spi.c b/drivers/base/regmap/regmap-spi.c new file mode 100644 index 0000000000..37ab23a9d0 --- /dev/null +++ b/drivers/base/regmap/regmap-spi.c @@ -0,0 +1,168 @@ +// SPDX-License-Identifier: GPL-2.0 +// +// Register map access API - SPI support +// +// Copyright 2011 Wolfson Microelectronics plc +// +// Author: Mark Brown <broonie@opensource.wolfsonmicro.com> + +#include <linux/regmap.h> +#include <linux/spi/spi.h> +#include <linux/module.h> + +#include "internal.h" + +struct regmap_async_spi { + struct regmap_async core; + struct spi_message m; + struct spi_transfer t[2]; +}; + +static void regmap_spi_complete(void *data) +{ + struct regmap_async_spi *async = data; + + regmap_async_complete_cb(&async->core, async->m.status); +} + +static int regmap_spi_write(void *context, const void *data, size_t count) +{ + struct device *dev = context; + struct spi_device *spi = to_spi_device(dev); + + return spi_write(spi, data, count); +} + +static int regmap_spi_gather_write(void *context, + const void *reg, size_t reg_len, + const void *val, size_t val_len) +{ + struct device *dev = context; + struct spi_device *spi = to_spi_device(dev); + struct spi_message m; + struct spi_transfer t[2] = { { .tx_buf = reg, .len = reg_len, }, + { .tx_buf = val, .len = val_len, }, }; + + spi_message_init(&m); + spi_message_add_tail(&t[0], &m); + spi_message_add_tail(&t[1], &m); + + return spi_sync(spi, &m); +} + +static int regmap_spi_async_write(void *context, + const void *reg, size_t reg_len, + const void *val, size_t val_len, + struct regmap_async *a) +{ + struct regmap_async_spi *async = container_of(a, + struct regmap_async_spi, + core); + struct device *dev = context; + struct spi_device *spi = to_spi_device(dev); + + async->t[0].tx_buf = reg; + async->t[0].len = reg_len; + async->t[1].tx_buf = val; + async->t[1].len = val_len; + + spi_message_init(&async->m); + spi_message_add_tail(&async->t[0], &async->m); + if (val) + spi_message_add_tail(&async->t[1], &async->m); + + async->m.complete = regmap_spi_complete; + async->m.context = async; + + return spi_async(spi, &async->m); +} + +static struct regmap_async *regmap_spi_async_alloc(void) +{ + struct regmap_async_spi *async_spi; + + async_spi = kzalloc(sizeof(*async_spi), GFP_KERNEL); + if (!async_spi) + return NULL; + + return &async_spi->core; +} + +static int regmap_spi_read(void *context, + const void *reg, size_t reg_size, + void *val, size_t val_size) +{ + struct device *dev = context; + struct spi_device *spi = to_spi_device(dev); + + return spi_write_then_read(spi, reg, reg_size, val, val_size); +} + +static const struct regmap_bus regmap_spi = { + .write = regmap_spi_write, + .gather_write = regmap_spi_gather_write, + .async_write = regmap_spi_async_write, + .async_alloc = regmap_spi_async_alloc, + .read = regmap_spi_read, + .read_flag_mask = 0x80, + .reg_format_endian_default = REGMAP_ENDIAN_BIG, + .val_format_endian_default = REGMAP_ENDIAN_BIG, +}; + +static const struct regmap_bus *regmap_get_spi_bus(struct spi_device *spi, + const struct regmap_config *config) +{ + size_t max_size = spi_max_transfer_size(spi); + size_t max_msg_size, reg_reserve_size; + struct regmap_bus *bus; + + if (max_size != SIZE_MAX) { + bus = kmemdup(®map_spi, sizeof(*bus), GFP_KERNEL); + if (!bus) + return ERR_PTR(-ENOMEM); + + max_msg_size = spi_max_message_size(spi); + reg_reserve_size = config->reg_bits / BITS_PER_BYTE + + config->pad_bits / BITS_PER_BYTE; + if (max_size + reg_reserve_size > max_msg_size) + max_size -= reg_reserve_size; + + bus->free_on_exit = true; + bus->max_raw_read = max_size; + bus->max_raw_write = max_size; + + return bus; + } + + return ®map_spi; +} + +struct regmap *__regmap_init_spi(struct spi_device *spi, + const struct regmap_config *config, + struct lock_class_key *lock_key, + const char *lock_name) +{ + const struct regmap_bus *bus = regmap_get_spi_bus(spi, config); + + if (IS_ERR(bus)) + return ERR_CAST(bus); + + return __regmap_init(&spi->dev, bus, &spi->dev, config, lock_key, lock_name); +} +EXPORT_SYMBOL_GPL(__regmap_init_spi); + +struct regmap *__devm_regmap_init_spi(struct spi_device *spi, + const struct regmap_config *config, + struct lock_class_key *lock_key, + const char *lock_name) +{ + const struct regmap_bus *bus = regmap_get_spi_bus(spi, config); + + if (IS_ERR(bus)) + return ERR_CAST(bus); + + return __devm_regmap_init(&spi->dev, bus, &spi->dev, config, lock_key, lock_name); +} +EXPORT_SYMBOL_GPL(__devm_regmap_init_spi); + +MODULE_LICENSE("GPL"); |