summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
-rw-r--r--include/linux/spi/spi.h15
1 files changed, 15 insertions, 0 deletions
diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
index cce80e6..3eebc6c 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;
@@ -832,6 +838,15 @@ 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
OpenPOWER on IntegriCloud