diff options
Diffstat (limited to 'include/linux/spi/spi.h')
| -rw-r--r-- | include/linux/spi/spi.h | 47 |
1 files changed, 22 insertions, 25 deletions
diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h index 68bb1c501d0..c47c4b4da97 100644 --- a/include/linux/spi/spi.h +++ b/include/linux/spi/spi.h @@ -80,6 +80,8 @@ struct spi_device { #define SPI_LSB_FIRST 0x08 /* per-word bits-on-wire */ #define SPI_3WIRE 0x10 /* SI/SO signals shared */ #define SPI_LOOP 0x20 /* loopback mode */ +#define SPI_NO_CS 0x40 /* 1 dev/bus, no chipselect */ +#define SPI_READY 0x80 /* slave pulls low to pause */ u8 bits_per_word; int irq; void *controller_state; @@ -204,6 +206,7 @@ static inline void spi_unregister_driver(struct spi_driver *sdrv) * SPI slaves, and are numbered from zero to num_chipselects. * each slave has a chipselect signal, but it's common that not * every chipselect is connected to a slave. + * @dma_alignment: SPI controller constraint on DMA buffers alignment. * @setup: updates the device mode and clocking records used by a * device's SPI controller; protocol code may call this. This * must fail if an unrecognized or unsupported mode is requested. @@ -239,7 +242,24 @@ struct spi_master { */ u16 num_chipselect; - /* setup mode and clock, etc (spi driver may call many times) */ + /* some SPI controllers pose alignment requirements on DMAable + * buffers; let protocol drivers know about these requirements. + */ + u16 dma_alignment; + + /* spi_device.mode flags understood by this controller driver */ + u16 mode_bits; + + /* other constraints relevant to this driver */ + u16 flags; +#define SPI_MASTER_HALF_DUPLEX BIT(0) /* can't do full duplex */ + + /* Setup mode and clock, etc (spi driver may call many times). + * + * IMPORTANT: this may be called when transfers to another + * device are active. DO NOT UPDATE SHARED REGISTERS in ways + * which could break those transfers. + */ int (*setup)(struct spi_device *spi); /* bidirectional bulk transfers @@ -512,30 +532,7 @@ static inline void spi_message_free(struct spi_message *m) kfree(m); } -/** - * spi_setup - setup SPI mode and clock rate - * @spi: the device whose settings are being modified - * Context: can sleep, and no requests are queued to the device - * - * SPI protocol drivers may need to update the transfer mode if the - * device doesn't work with its default. They may likewise need - * to update clock rates or word sizes from initial values. This function - * changes those settings, and must be called from a context that can sleep. - * Except for SPI_CS_HIGH, which takes effect immediately, the changes take - * effect the next time the device is selected and data is transferred to - * or from it. When this function returns, the spi device is deselected. - * - * Note that this call will fail if the protocol driver specifies an option - * that the underlying controller or its driver does not support. For - * example, not all hardware supports wire transfers using nine bit words, - * LSB-first wire encoding, or active-high chipselects. - */ -static inline int -spi_setup(struct spi_device *spi) -{ - return spi->master->setup(spi); -} - +extern int spi_setup(struct spi_device *spi); /** * spi_async - asynchronous SPI transfer |