backport-include/linux/spi/spi.h

#ifndef _BACKPORTS_LINUX_SPI_H
#define _BACKPORTS_LINUX_SPI_H 1

#include_next <linux/spi/spi.h>

#ifndef module_spi_driver
/**
 * module_spi_driver() - Helper macro for registering a SPI driver
 * @__spi_driver: spi_driver struct
 *
 * Helper macro for SPI drivers which do not do anything special in module
 * init/exit. This eliminates a lot of boilerplate. Each module may only
 * use this macro once, and calling it replaces module_init() and module_exit()
 */
#define module_spi_driver(__spi_driver) \
	module_driver(__spi_driver, spi_register_driver, \
			spi_unregister_driver)
#endif


#if LINUX_VERSION_CODE < KERNEL_VERSION(3,9,0)
/**
 * spi_message_init_with_transfers - Initialize spi_message and append transfers
 * @m: spi_message to be initialized
 * @xfers: An array of spi transfers
 * @num_xfers: Number of items in the xfer array
 *
 * This function initializes the given spi_message and adds each spi_transfer in
 * the given array to the message.
 */
#define spi_message_init_with_transfers LINUX_BACKPORT(spi_message_init_with_transfers)
static inline void
spi_message_init_with_transfers(struct spi_message *m,
struct spi_transfer *xfers, unsigned int num_xfers)
{
	unsigned int i;

	spi_message_init(m);
	for (i = 0; i < num_xfers; ++i)
		spi_message_add_tail(&xfers[i], m);
}

/**
 * spi_sync_transfer - synchronous SPI data transfer
 * @spi: device with which data will be exchanged
 * @xfers: An array of spi_transfers
 * @num_xfers: Number of items in the xfer array
 * Context: can sleep
 *
 * Does a synchronous SPI data transfer of the given spi_transfer array.
 *
 * For more specific semantics see spi_sync().
 *
 * It returns zero on success, else a negative error code.
 */
#define spi_sync_transfer LINUX_BACKPORT(spi_sync_transfer)
static inline int
spi_sync_transfer(struct spi_device *spi, struct spi_transfer *xfers,
	unsigned int num_xfers)
{
	struct spi_message msg;

	spi_message_init_with_transfers(&msg, xfers, num_xfers);

	return spi_sync(spi, &msg);
}
#endif /* < 3.9 */

#endif /* _BACKPORTS_LINUX_SPI_H */