2  * SPI init/core code
29 #include <linux/spi/spi.h>
36 	struct spi_device	*spi = to_spi_device(dev);  in spidev_release()  local
38 	/* spi masters may cleanup for released devices */  in spidev_release()
39 	if (spi->master->cleanup)  in spidev_release()
40 		spi->master->cleanup(spi);  in spidev_release()
42 	spi_master_put(spi->master);  in spidev_release()
43 	kfree(spi);  in spidev_release()
49 	const struct spi_device	*spi = to_spi_device(dev);  in modalias_show()  local
51 	return sprintf(buf, "%s\n", spi->modalias);  in modalias_show()
84 	const struct spi_device	*spi = to_spi_device(dev);  in spi_match_device()  local
92 		return !!spi_match_id(sdrv->id_table, spi);  in spi_match_device()
94 	return strcmp(spi->modalias, drv->name) == 0;  in spi_match_device()
99 	const struct spi_device		*spi = to_spi_device(dev);  in spi_uevent()  local
101 	add_uevent_var(env, "MODALIAS=%s%s", SPI_MODULE_PREFIX, spi->modalias);  in spi_uevent()
219 	.name		= "spi",
250  * spi_register_driver - register a SPI driver
269 /* SPI devices should normally not be created by SPI device drivers; that
270  * would make them board-specific.  Similarly with SPI master drivers.
290  * spi_alloc_device - Allocate a new SPI device
300  * spi_device structure to add it to the SPI master.  If the caller
308 	struct spi_device	*spi;  in spi_alloc_device()  local
314 	spi = kzalloc(sizeof *spi, GFP_KERNEL);  in spi_alloc_device()
315 	if (!spi) {  in spi_alloc_device()
321 	spi->master = master;  in spi_alloc_device()
322 	spi->dev.parent = &master->dev;  in spi_alloc_device()
323 	spi->dev.bus = &spi_bus_type;  in spi_alloc_device()
324 	spi->dev.release = spidev_release;  in spi_alloc_device()
325 	device_initialize(&spi->dev);  in spi_alloc_device()
326 	return spi;  in spi_alloc_device()
332  * @spi: spi_device to register
335  * spi_alloc_device can be added onto the spi bus with this function.
339 int spi_add_device(struct spi_device *spi)  in spi_add_device()  argument
342 	struct device *dev = spi->master->dev.parent;  in spi_add_device()
347 	if (spi->chip_select >= spi->master->num_chipselect) {  in spi_add_device()
349 			spi->chip_select,  in spi_add_device()
350 			spi->master->num_chipselect);  in spi_add_device()
355 	dev_set_name(&spi->dev, "%s.%u", dev_name(&spi->master->dev),  in spi_add_device()
356 			spi->chip_select);  in spi_add_device()
365 	d = bus_find_device_by_name(&spi_bus_type, NULL, dev_name(&spi->dev));  in spi_add_device()
368 				spi->chip_select);  in spi_add_device()
378 	status = spi_setup(spi);  in spi_add_device()
381 				dev_name(&spi->dev), status);  in spi_add_device()
386 	status = device_add(&spi->dev);  in spi_add_device()
389 				dev_name(&spi->dev), status);  in spi_add_device()
391 		dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev));  in spi_add_device()
400  * spi_new_device - instantiate one new SPI device
402  * @chip: Describes the SPI device
466  * spi_register_board_info - register SPI devices for a given board
472  * with segments of the SPI device table.  Any device nodes are created later,
473  * after the relevant parent SPI controller (bus_num) is defined.  We keep
478  * SPI devices through its expansion connector, so code initializing that board
479  * would naturally declare its SPI devices.
526  * spi_alloc_master - allocate SPI master controller
533  * This call is used only by SPI master controller drivers, which are the
537  * This must be called from context that can sleep.  It returns the SPI
565  * spi_register_master - register SPI master controller
569  * SPI master controllers connect to their drivers using some non-SPI bus,
571  * includes calling spi_register_master() to hook up to this SPI bus glue.
573  * SPI controllers use board specific (often SOC specific) bus numbers,
574  * and board-specific addressing for SPI devices combines those numbers
575  * with chip select numbers.  Since SPI does not directly support dynamic
617 	dev_set_name(&master->dev, "spi%u", master->bus_num);  in spi_register_master()
647  * spi_unregister_master - unregister SPI master controller
651  * This call is used only by SPI master controller drivers, which are the
705 /* Core methods for SPI master protocol drivers.  Some of the
710  * spi_setup - setup SPI mode and clock rate
711  * @spi: the device whose settings are being modified
714  * SPI protocol drivers may need to update the transfer mode if the
720  * or from it.  When this function returns, the spi device is deselected.
727 int spi_setup(struct spi_device *spi)  in spi_setup()  argument
735 	bad_bits = spi->mode & ~spi->master->mode_bits;  in spi_setup()
737 		dev_err(&spi->dev, "setup: unsupported mode bits %x\n",  in spi_setup()
742 	if (!spi->bits_per_word)  in spi_setup()
743 		spi->bits_per_word = 8;  in spi_setup()
745 	status = spi->master->setup(spi);  in spi_setup()
747 	dev_dbg(&spi->dev, "setup mode %d, %s%s%s%s"  in spi_setup()
749 			(int) (spi->mode & (SPI_CPOL | SPI_CPHA)),  in spi_setup()
750 			(spi->mode & SPI_CS_HIGH) ? "cs_high, " : "",  in spi_setup()
751 			(spi->mode & SPI_LSB_FIRST) ? "lsb, " : "",  in spi_setup()
752 			(spi->mode & SPI_3WIRE) ? "3wire, " : "",  in spi_setup()
753 			(spi->mode & SPI_LOOP) ? "loopback, " : "",  in spi_setup()
754 			spi->bits_per_word, spi->max_speed_hz,  in spi_setup()
761 static int __spi_async(struct spi_device *spi, struct spi_message *message)  in __spi_async()  argument
763 	struct spi_master *master = spi->master;  in __spi_async()
771 			|| (spi->mode & SPI_3WIRE)) {  in __spi_async()
785 	message->spi = spi;  in __spi_async()
787 	return master->transfer(spi, message);  in __spi_async()
791  * spi_async - asynchronous SPI transfer
792  * @spi: device with which data will be exchanged
804  * deallocate the associated memory; it's no longer in use by any SPI
819 int spi_async(struct spi_device *spi, struct spi_message *message)  in spi_async()  argument
821 	struct spi_master *master = spi->master;  in spi_async()
830 		ret = __spi_async(spi, message);  in spi_async()
840  * @spi: device with which data will be exchanged
852  * deallocate the associated memory; it's no longer in use by any SPI
867 int spi_async_locked(struct spi_device *spi, struct spi_message *message)  in spi_async_locked()  argument
869 	struct spi_master *master = spi->master;  in spi_async_locked()
875 	ret = __spi_async(spi, message);  in spi_async_locked()
887 /* Utility methods for SPI master protocol drivers, layered on
897 static int __spi_sync(struct spi_device *spi, struct spi_message *message,  in __spi_sync()  argument
902 	struct spi_master *master = spi->master;  in __spi_sync()
910 	status = spi_async_locked(spi, message);  in __spi_sync()
924  * spi_sync - blocking/synchronous SPI data transfers
925  * @spi: device with which data will be exchanged
933  * Note that the SPI device's chip select is active during the message,
944 int spi_sync(struct spi_device *spi, struct spi_message *message)  in spi_sync()  argument
946 	return __spi_sync(spi, message, 0);  in spi_sync()
952  * @spi: device with which data will be exchanged
961  * SPI bus. It has to be preceded by a spi_bus_lock call. The SPI bus must
966 int spi_sync_locked(struct spi_device *spi, struct spi_message *message)  in spi_sync_locked()  argument
968 	return __spi_sync(spi, message, 1);  in spi_sync_locked()
973  * spi_bus_lock - obtain a lock for exclusive SPI bus usage
974  * @master: SPI bus master that should be locked for exclusive bus access
981  * SPI bus. The SPI bus must be released by a spi_bus_unlock call when the
983  * and spi_async_locked calls when the SPI bus lock is held.
1004  * spi_bus_unlock - release the lock for exclusive SPI bus usage
1005  * @master: SPI bus master that was locked for exclusive bus access
1011  * This call releases an SPI bus lock previously obtained by an spi_bus_lock
1032  * spi_write_then_read - SPI synchronous write followed by read
1033  * @spi: device with which data will be exchanged
1050 int spi_write_then_read(struct spi_device *spi,  in spi_write_then_read()  argument
1092 	status = spi_sync(spi, &message);  in spi_write_then_read()