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-rw-r--r--include/linux/spi/spi.h46
1 files changed, 40 insertions, 6 deletions
diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
index a1d4ca29086..e713543336f 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.
@@ -234,7 +237,7 @@ static inline void spi_unregister_driver(struct spi_driver *sdrv)
* @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
+ * supported. 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.
* @min_speed_hz: Lowest supported transfer speed
@@ -259,13 +262,14 @@ static inline void spi_unregister_driver(struct spi_driver *sdrv)
* @cur_msg: the currently in-flight message
* @cur_msg_prepared: spi_prepare_message was called for the currently
* in-flight message
- * @xfer_completion: used by core tranfer_one_message()
+ * @xfer_completion: used by core transfer_one_message()
* @busy: message pump is busy
* @running: message pump is running
* @rt: whether this queue is set to run as a realtime task
* @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)
@@ -495,7 +525,7 @@ extern struct spi_master *spi_busnum_to_master(u16 busnum);
* @rx_buf: data to be read (dma-safe memory), or NULL
* @tx_dma: DMA address of tx_buf, if @spi_message.is_dma_mapped
* @rx_dma: DMA address of rx_buf, if @spi_message.is_dma_mapped
- * @tx_nbits: number of bits used for writting. If 0 the default
+ * @tx_nbits: number of bits used for writing. If 0 the default
* (SPI_NBITS_SINGLE) is used.
* @rx_nbits: number of bits used for reading. If 0 the default
* (SPI_NBITS_SINGLE) is used.
@@ -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.
@@ -553,7 +585,7 @@ extern struct spi_master *spi_busnum_to_master(u16 busnum);
* by the results of previous messages and where the whole transaction
* ends when the chipselect goes intactive.
*
- * When SPI can transfer in 1x,2x or 4x. It can get this tranfer information
+ * When SPI can transfer in 1x,2x or 4x. It can get this transfer information
* from device through @tx_nbits and @rx_nbits. In Bi-direction, these
* two should both be set. User can set transfer mode with SPI_NBITS_SINGLE(1x)
* SPI_NBITS_DUAL(2x) and SPI_NBITS_QUAD(4x) to support these three transfer.
@@ -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;