diff options
Diffstat (limited to 'include/linux/spi')
| -rw-r--r-- | include/linux/spi/spi.h | 22 |
1 files changed, 21 insertions, 1 deletions
diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h index 075bede66521..53be3a4c60cb 100644 --- a/include/linux/spi/spi.h +++ b/include/linux/spi/spi.h @@ -425,6 +425,12 @@ struct spi_master { #define SPI_MASTER_MUST_RX BIT(3) /* requires rx */ #define SPI_MASTER_MUST_TX BIT(4) /* requires tx */ + /* + * on some hardware transfer size may be constrained + * the limit may depend on device transfer settings + */ + size_t (*max_transfer_size)(struct spi_device *spi); + /* lock and mutex for SPI bus locking */ spinlock_t bus_lock_spinlock; struct mutex bus_lock_mutex; @@ -762,10 +768,15 @@ struct spi_message { void *state; }; +static inline void spi_message_init_no_memset(struct spi_message *m) +{ + INIT_LIST_HEAD(&m->transfers); +} + static inline void spi_message_init(struct spi_message *m) { memset(m, 0, sizeof *m); - INIT_LIST_HEAD(&m->transfers); + spi_message_init_no_memset(m); } static inline void @@ -832,6 +843,15 @@ extern int spi_async(struct spi_device *spi, struct spi_message *message); extern int spi_async_locked(struct spi_device *spi, struct spi_message *message); +static inline size_t +spi_max_transfer_size(struct spi_device *spi) +{ + struct spi_master *master = spi->master; + if (!master->max_transfer_size) + return SIZE_MAX; + return master->max_transfer_size(spi); +} + /*---------------------------------------------------------------------------*/ /* All these synchronous SPI transfer routines are utilities layered |