diff options
Diffstat (limited to 'include/linux/spi/spi.h')
| -rw-r--r-- | include/linux/spi/spi.h | 38 |
1 files changed, 36 insertions, 2 deletions
diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h index a1d4ca2..36c86ef 100644 --- a/include/linux/spi/spi.h +++ b/include/linux/spi/spi.h @@ -24,6 +24,9 @@ #include <linux/slab.h> #include <linux/kthread.h> #include <linux/completion.h> +#include <linux/scatterlist.h> + +struct dma_chan; /* * INTERFACES between SPI master-side drivers and SPI infrastructure. @@ -266,6 +269,7 @@ static inline void spi_unregister_driver(struct spi_driver *sdrv) * @auto_runtime_pm: the core should ensure a runtime PM reference is held * while the hardware is prepared, using the parent * device for the spidev + * @max_dma_len: Maximum length of a DMA transfer for the device. * @prepare_transfer_hardware: a message will soon arrive from the queue * so the subsystem requests the driver to prepare the transfer hardware * by issuing this call @@ -273,7 +277,7 @@ static inline void spi_unregister_driver(struct spi_driver *sdrv) * message while queuing transfers that arrive in the meantime. When the * driver is finished with this message, it must call * spi_finalize_current_message() so the subsystem can issue the next - * transfer + * message * @unprepare_transfer_hardware: there are currently no more messages on the * queue so the subsystem notifies the driver that it may relax the * hardware by issuing this call @@ -287,7 +291,10 @@ static inline void spi_unregister_driver(struct spi_driver *sdrv) * - return 1 if the transfer is still in progress. When * the driver is finished with this transfer it must * call spi_finalize_current_transfer() so the subsystem - * can issue the next transfer + * can issue the next transfer. Note: transfer_one and + * transfer_one_message are mutually exclusive; when both + * are set, the generic subsystem does not call your + * transfer_one callback. * @unprepare_message: undo any work done by prepare_message(). * @cs_gpios: Array of GPIOs to use as chip select lines; one per CS * number. Any individual value may be -ENOENT for CS lines that @@ -345,6 +352,8 @@ struct spi_master { #define SPI_MASTER_HALF_DUPLEX BIT(0) /* can't do full duplex */ #define SPI_MASTER_NO_RX BIT(1) /* can't do buffer read */ #define SPI_MASTER_NO_TX BIT(2) /* can't do buffer write */ +#define SPI_MASTER_MUST_RX BIT(3) /* requires rx */ +#define SPI_MASTER_MUST_TX BIT(4) /* requires tx */ /* lock and mutex for SPI bus locking */ spinlock_t bus_lock_spinlock; @@ -387,6 +396,17 @@ struct spi_master { void (*cleanup)(struct spi_device *spi); /* + * Used to enable core support for DMA handling, if can_dma() + * exists and returns true then the transfer will be mapped + * prior to transfer_one() being called. The driver should + * not modify or store xfer and dma_tx and dma_rx must be set + * while the device is prepared. + */ + bool (*can_dma)(struct spi_master *master, + struct spi_device *spi, + struct spi_transfer *xfer); + + /* * These hooks are for drivers that want to use the generic * master transfer queueing mechanism. If these are used, the * transfer() function above must NOT be specified by the driver. @@ -404,7 +424,9 @@ struct spi_master { bool rt; bool auto_runtime_pm; bool cur_msg_prepared; + bool cur_msg_mapped; struct completion xfer_completion; + size_t max_dma_len; int (*prepare_transfer_hardware)(struct spi_master *master); int (*transfer_one_message)(struct spi_master *master, @@ -425,6 +447,14 @@ struct spi_master { /* gpio chip select */ int *cs_gpios; + + /* DMA channels for use with core dmaengine helpers */ + struct dma_chan *dma_tx; + struct dma_chan *dma_rx; + + /* dummy data for full duplex devices */ + void *dummy_rx; + void *dummy_tx; }; static inline void *spi_master_get_devdata(struct spi_master *master) @@ -509,6 +539,8 @@ extern struct spi_master *spi_busnum_to_master(u16 busnum); * (optionally) changing the chipselect status, then starting * the next transfer or completing this @spi_message. * @transfer_list: transfers are sequenced through @spi_message.transfers + * @tx_sg: Scatterlist for transmit, currently not for client use + * @rx_sg: Scatterlist for receive, currently not for client use * * SPI transfers always write the same number of bytes as they read. * Protocol drivers should always provide @rx_buf and/or @tx_buf. @@ -576,6 +608,8 @@ struct spi_transfer { dma_addr_t tx_dma; dma_addr_t rx_dma; + struct sg_table tx_sg; + struct sg_table rx_sg; unsigned cs_change:1; unsigned tx_nbits:3; |
