diff options
Diffstat (limited to 'include/linux/spi/spi.h')
-rw-r--r-- | include/linux/spi/spi.h | 39 |
1 files changed, 3 insertions, 36 deletions
diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h index e2051f39f6a8..97b60b37f445 100644 --- a/include/linux/spi/spi.h +++ b/include/linux/spi/spi.h | |||
@@ -258,6 +258,8 @@ struct spi_master { | |||
258 | /* other constraints relevant to this driver */ | 258 | /* other constraints relevant to this driver */ |
259 | u16 flags; | 259 | u16 flags; |
260 | #define SPI_MASTER_HALF_DUPLEX BIT(0) /* can't do full duplex */ | 260 | #define SPI_MASTER_HALF_DUPLEX BIT(0) /* can't do full duplex */ |
261 | #define SPI_MASTER_NO_RX BIT(1) /* can't do buffer read */ | ||
262 | #define SPI_MASTER_NO_TX BIT(2) /* can't do buffer write */ | ||
261 | 263 | ||
262 | /* Setup mode and clock, etc (spi driver may call many times). | 264 | /* Setup mode and clock, etc (spi driver may call many times). |
263 | * | 265 | * |
@@ -538,42 +540,7 @@ static inline void spi_message_free(struct spi_message *m) | |||
538 | } | 540 | } |
539 | 541 | ||
540 | extern int spi_setup(struct spi_device *spi); | 542 | extern int spi_setup(struct spi_device *spi); |
541 | 543 | extern int spi_async(struct spi_device *spi, struct spi_message *message); | |
542 | /** | ||
543 | * spi_async - asynchronous SPI transfer | ||
544 | * @spi: device with which data will be exchanged | ||
545 | * @message: describes the data transfers, including completion callback | ||
546 | * Context: any (irqs may be blocked, etc) | ||
547 | * | ||
548 | * This call may be used in_irq and other contexts which can't sleep, | ||
549 | * as well as from task contexts which can sleep. | ||
550 | * | ||
551 | * The completion callback is invoked in a context which can't sleep. | ||
552 | * Before that invocation, the value of message->status is undefined. | ||
553 | * When the callback is issued, message->status holds either zero (to | ||
554 | * indicate complete success) or a negative error code. After that | ||
555 | * callback returns, the driver which issued the transfer request may | ||
556 | * deallocate the associated memory; it's no longer in use by any SPI | ||
557 | * core or controller driver code. | ||
558 | * | ||
559 | * Note that although all messages to a spi_device are handled in | ||
560 | * FIFO order, messages may go to different devices in other orders. | ||
561 | * Some device might be higher priority, or have various "hard" access | ||
562 | * time requirements, for example. | ||
563 | * | ||
564 | * On detection of any fault during the transfer, processing of | ||
565 | * the entire message is aborted, and the device is deselected. | ||
566 | * Until returning from the associated message completion callback, | ||
567 | * no other spi_message queued to that device will be processed. | ||
568 | * (This rule applies equally to all the synchronous transfer calls, | ||
569 | * which are wrappers around this core asynchronous primitive.) | ||
570 | */ | ||
571 | static inline int | ||
572 | spi_async(struct spi_device *spi, struct spi_message *message) | ||
573 | { | ||
574 | message->spi = spi; | ||
575 | return spi->master->transfer(spi, message); | ||
576 | } | ||
577 | 544 | ||
578 | /*---------------------------------------------------------------------------*/ | 545 | /*---------------------------------------------------------------------------*/ |
579 | 546 | ||