Idiomatically, write functions should take const pointers to the data buffer, as they don't change the data. They are also likely to be called from functions that receive a const data pointer.
Internally the pointer is passed to function/structs shared with the read functions, requiring a cast, but this is an implementation detail that should be hidden by the public API.
Signed-off-by: Richard Fitzgerald rf@opensource.cirrus.com --- drivers/soundwire/bus.c | 8 ++++---- include/linux/soundwire/sdw.h | 2 +- 2 files changed, 5 insertions(+), 5 deletions(-)
diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c index a9e0aa72654d..49c66deba106 100644 --- a/drivers/soundwire/bus.c +++ b/drivers/soundwire/bus.c @@ -394,13 +394,13 @@ sdw_nread_no_pm(struct sdw_slave *slave, u32 addr, size_t count, u8 *val) }
static int -sdw_nwrite_no_pm(struct sdw_slave *slave, u32 addr, size_t count, u8 *val) +sdw_nwrite_no_pm(struct sdw_slave *slave, u32 addr, size_t count, const u8 *val) { struct sdw_msg msg; int ret;
ret = sdw_fill_msg(&msg, slave, addr, count, - slave->dev_num, SDW_MSG_FLAG_WRITE, val); + slave->dev_num, SDW_MSG_FLAG_WRITE, (u8 *)val); if (ret < 0) return ret;
@@ -535,9 +535,9 @@ EXPORT_SYMBOL(sdw_nread); * @slave: SDW Slave * @addr: Register address * @count: length - * @val: Buffer for values to be read + * @val: Buffer for values to be written */ -int sdw_nwrite(struct sdw_slave *slave, u32 addr, size_t count, u8 *val) +int sdw_nwrite(struct sdw_slave *slave, u32 addr, size_t count, const u8 *val) { int ret;
diff --git a/include/linux/soundwire/sdw.h b/include/linux/soundwire/sdw.h index ced07f8fde87..ee45d2984334 100644 --- a/include/linux/soundwire/sdw.h +++ b/include/linux/soundwire/sdw.h @@ -1040,7 +1040,7 @@ int sdw_write(struct sdw_slave *slave, u32 addr, u8 value); int sdw_write_no_pm(struct sdw_slave *slave, u32 addr, u8 value); int sdw_read_no_pm(struct sdw_slave *slave, u32 addr); int sdw_nread(struct sdw_slave *slave, u32 addr, size_t count, u8 *val); -int sdw_nwrite(struct sdw_slave *slave, u32 addr, size_t count, u8 *val); +int sdw_nwrite(struct sdw_slave *slave, u32 addr, size_t count, const u8 *val); int sdw_compare_devid(struct sdw_slave *slave, struct sdw_slave_id id); void sdw_extract_slave_id(struct sdw_bus *bus, u64 addr, struct sdw_slave_id *id);