diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/spi/spi.h | 30 | ||||
| -rw-r--r-- | include/linux/spi/spi_bitbang.h | 5 |
2 files changed, 35 insertions, 0 deletions
diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h index 68bb1c501d0..bf21ef63984 100644 --- a/include/linux/spi/spi.h +++ b/include/linux/spi/spi.h @@ -264,6 +264,13 @@ struct spi_master { int (*transfer)(struct spi_device *spi, struct spi_message *mesg); + /* + * Synchronous non blocking transfer function. Should guarantee + * data availability when it returns + */ + int (*transfer_sync)(struct spi_device *spi, + struct spi_message *mesg); + /* called on release() to free memory provided by spi_master */ void (*cleanup)(struct spi_device *spi); }; @@ -573,6 +580,29 @@ spi_async(struct spi_device *spi, struct spi_message *message) return spi->master->transfer(spi, message); } +/** + * spi_non_blocking_transfer - Synchronous, non blocking transfer + * @spi: device with which data will be exchanged + * @message: describes the data transfers with optional completion handlers + * Context: any (irqs may be blocked, etc) + * + * Data is guaranteed to be written or read when this function returns. + * + * Note : This may not be supported by all spi masters. + */ + +static inline int +spi_non_blocking_transfer(struct spi_device *spi, struct spi_message *message) +{ + if (unlikely(!spi->master->transfer_sync)) { + dev_err(&spi->master->dev, + "non-blocking transfers not supported\n"); + return -EIO; + } + + return spi->master->transfer_sync(spi, message); +} + /*---------------------------------------------------------------------------*/ /* All these synchronous SPI transfer routines are utilities layered diff --git a/include/linux/spi/spi_bitbang.h b/include/linux/spi/spi_bitbang.h index bf8de281b4e..476a7afdc97 100644 --- a/include/linux/spi/spi_bitbang.h +++ b/include/linux/spi/spi_bitbang.h @@ -31,6 +31,9 @@ struct spi_bitbang { u8 use_dma; u8 flags; /* extra spi->mode support */ + /* Support for synchronous non blocking transfers */ + int non_blocking_transfer; + struct spi_master *master; /* setup_transfer() changes clock and/or wordsize to match settings @@ -62,6 +65,8 @@ extern void spi_bitbang_cleanup(struct spi_device *spi); extern int spi_bitbang_transfer(struct spi_device *spi, struct spi_message *m); extern int spi_bitbang_setup_transfer(struct spi_device *spi, struct spi_transfer *t); +extern int spi_bitbang_transfer_sync(struct spi_device *spi, + struct spi_message *m); /* start or stop queue processing */ extern int spi_bitbang_start(struct spi_bitbang *spi); |