diff options
Diffstat (limited to 'include/linux/spi/spi.h')
| -rw-r--r-- | include/linux/spi/spi.h | 61 |
1 files changed, 59 insertions, 2 deletions
diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h index 887116dbce2c..8c62ba74dd91 100644 --- a/include/linux/spi/spi.h +++ b/include/linux/spi/spi.h @@ -23,6 +23,7 @@ #include <linux/mod_devicetable.h> #include <linux/slab.h> #include <linux/kthread.h> +#include <linux/completion.h> /* * INTERFACES between SPI master-side drivers and SPI infrastructure. @@ -150,8 +151,7 @@ static inline void *spi_get_drvdata(struct spi_device *spi) } struct spi_message; - - +struct spi_transfer; /** * struct spi_driver - Host side "protocol" driver @@ -257,6 +257,9 @@ static inline void spi_unregister_driver(struct spi_driver *sdrv) * @queue_lock: spinlock to syncronise access to message queue * @queue: message queue * @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() * @busy: message pump is busy * @running: message pump is running * @rt: whether this queue is set to run as a realtime task @@ -274,6 +277,16 @@ static inline void spi_unregister_driver(struct spi_driver *sdrv) * @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 + * @set_cs: assert or deassert chip select, true to assert. May be called + * from interrupt context. + * @prepare_message: set up the controller to transfer a single message, + * for example doing DMA mapping. Called from threaded + * context. + * @transfer_one: transfer a single spi_transfer. When the + * driver is finished with this transfer it must call + * spi_finalize_current_transfer() so the subsystem can issue + * the next transfer + * @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 * are not GPIOs (driven by the SPI controller itself). @@ -388,11 +401,25 @@ struct spi_master { bool running; bool rt; bool auto_runtime_pm; + bool cur_msg_prepared; + struct completion xfer_completion; int (*prepare_transfer_hardware)(struct spi_master *master); int (*transfer_one_message)(struct spi_master *master, struct spi_message *mesg); int (*unprepare_transfer_hardware)(struct spi_master *master); + int (*prepare_message)(struct spi_master *master, + struct spi_message *message); + int (*unprepare_message)(struct spi_master *master, + struct spi_message *message); + + /* + * These hooks are for drivers that use a generic implementation + * of transfer_one_message() provied by the core. + */ + void (*set_cs)(struct spi_device *spi, bool enable); + int (*transfer_one)(struct spi_master *master, struct spi_device *spi, + struct spi_transfer *transfer); /* gpio chip select */ int *cs_gpios; @@ -428,12 +455,15 @@ extern int spi_master_resume(struct spi_master *master); /* Calls the driver make to interact with the message queue */ extern struct spi_message *spi_get_next_queued_message(struct spi_master *master); extern void spi_finalize_current_message(struct spi_master *master); +extern void spi_finalize_current_transfer(struct spi_master *master); /* the spi driver core manages memory for the spi_master classdev */ extern struct spi_master * spi_alloc_master(struct device *host, unsigned size); extern int spi_register_master(struct spi_master *master); +extern int devm_spi_register_master(struct device *dev, + struct spi_master *master); extern void spi_unregister_master(struct spi_master *master); extern struct spi_master *spi_busnum_to_master(u16 busnum); @@ -823,6 +853,33 @@ static inline ssize_t spi_w8r16(struct spi_device *spi, u8 cmd) return (status < 0) ? status : result; } +/** + * spi_w8r16be - SPI synchronous 8 bit write followed by 16 bit big-endian read + * @spi: device with which data will be exchanged + * @cmd: command to be written before data is read back + * Context: can sleep + * + * This returns the (unsigned) sixteen bit number returned by the device in cpu + * endianness, or else a negative error code. Callable only from contexts that + * can sleep. + * + * This function is similar to spi_w8r16, with the exception that it will + * convert the read 16 bit data word from big-endian to native endianness. + * + */ +static inline ssize_t spi_w8r16be(struct spi_device *spi, u8 cmd) + +{ + ssize_t status; + __be16 result; + + status = spi_write_then_read(spi, &cmd, 1, &result, 2); + if (status < 0) + return status; + + return be16_to_cpu(result); +} + /*---------------------------------------------------------------------------*/ /* |