1 files changed, 8 insertions, 0 deletions

diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
index 38c2b925923d..733eb5ee31c5 100644
--- a/include/linux/spi/spi.h
+++ b/include/linux/spi/spi.h
@@ -228,6 +228,11 @@ static inline void spi_unregister_driver(struct spi_driver *sdrv)
  *      every chipselect is connected to a slave.
  * @dma_alignment: SPI controller constraint on DMA buffers alignment.
  * @mode_bits: flags understood by this controller driver
+ * @bits_per_word_mask: A mask indicating which values of bits_per_word are
+ *      supported by the driver. Bit n indicates that a bits_per_word n+1 is
+ *      suported. If set, the SPI core will reject any transfer with an
+ *      unsupported bits_per_word. If not set, this value is simply ignored,
+ *      and it's up to the individual driver to perform any validation.
  * @flags: other constraints relevant to this driver
  * @bus_lock_spinlock: spinlock for SPI bus locking
  * @bus_lock_mutex: mutex for SPI bus locking
@@ -301,6 +306,9 @@ struct spi_master {
         /* spi_device.mode flags understood by this controller driver */
         u16                     mode_bits;
 
+        /* bitmask of supported bits_per_word for transfers */
+        u32                     bits_per_word_mask;
+
         /* other constraints relevant to this driver */
         u16                     flags;
 #define SPI_MASTER_HALF_DUPLEX  BIT(0)          /* can't do full duplex */