1 /* SPDX-License-Identifier: GPL-2.0-or-later
18 #include <uapi/linux/spi/spi.h>
31  * INTERFACES between SPI master-side drivers and SPI slave protocol handlers,
32  * and SPI infrastructure.
37  * struct spi_statistics - statistics for spi transfers
38  * @syncp:         seqcount to protect members in this struct for per-cpu udate
39  *                 on 32-bit systems
41  * @messages:      number of spi-messages handled
90 		u64_stats_update_begin(&__lstats->syncp);		\
91 		u64_stats_add(&__lstats->field, count);			\
92 		u64_stats_update_end(&__lstats->syncp);			\
101 		u64_stats_update_begin(&__lstats->syncp);		\
102 		u64_stats_inc(&__lstats->field);			\
103 		u64_stats_update_end(&__lstats->syncp);			\
108  * struct spi_delay - SPI delay information
124  * struct spi_device - Controller side proxy for an SPI slave device
126  * @controller: SPI controller used with the device.
132  * @mode: The spi mode defines how data is clocked out and in.
138  *	like eight or 12 bits are common.  In-memory wordsizes are
147  * @controller_data: Board-specific definitions for controller, such as
167  * A @spi_device is used to interchange data between an SPI slave
189 	 * which is defined in 'include/uapi/linux/spi/spi.h'.
195 #define SPI_MODE_KERNEL_MASK	(~(BIT(30) - 1))
203 	struct spi_delay	word_delay; /* Inter-word delay */
215 	 *  - memory packing (12 bit samples into low bits, others zeroed)
216 	 *  - priority
217 	 *  - chipselect delays
218 	 *  - ...
232 static inline struct spi_device *spi_dev_get(struct spi_device *spi)  in spi_dev_get()  argument
234 	return (spi && get_device(&spi->dev)) ? spi : NULL;  in spi_dev_get()
237 static inline void spi_dev_put(struct spi_device *spi)  in spi_dev_put()  argument
239 	if (spi)  in spi_dev_put()
240 		put_device(&spi->dev);  in spi_dev_put()
244 static inline void *spi_get_ctldata(struct spi_device *spi)  in spi_get_ctldata()  argument
246 	return spi->controller_state;  in spi_get_ctldata()
249 static inline void spi_set_ctldata(struct spi_device *spi, void *state)  in spi_set_ctldata()  argument
251 	spi->controller_state = state;  in spi_set_ctldata()
256 static inline void spi_set_drvdata(struct spi_device *spi, void *data)  in spi_set_drvdata()  argument
258 	dev_set_drvdata(&spi->dev, data);  in spi_set_drvdata()
261 static inline void *spi_get_drvdata(struct spi_device *spi)  in spi_get_drvdata()  argument
263 	return dev_get_drvdata(&spi->dev);  in spi_get_drvdata()
269  * struct spi_driver - Host side "protocol" driver
270  * @id_table: List of SPI devices supported by this driver
271  * @probe: Binds this driver to the spi device.  Drivers can verify
275  * @remove: Unbinds this driver from the spi device
278  * @driver: SPI device drivers should initialize the name and owner
281  * This represents the kind of device driver that uses SPI messages to
282  * interact with the hardware at the other end of a SPI link.  It's called
284  * directly to SPI hardware (which is what the underlying SPI controller
295 	int			(*probe)(struct spi_device *spi);
296 	void			(*remove)(struct spi_device *spi);
297 	void			(*shutdown)(struct spi_device *spi);
309  * spi_unregister_driver - reverse effect of spi_register_driver
316 		driver_unregister(&sdrv->driver);  in spi_unregister_driver()
319 extern struct spi_device *spi_new_ancillary_device(struct spi_device *spi, u8 chip_select);
326  * module_spi_driver() - Helper macro for registering a SPI driver
329  * Helper macro for SPI drivers which do not do anything special in module
338  * struct spi_controller - interface to SPI master or slave controller
341  * @bus_num: board-specific (and often SOC-specific) identifier for a
342  *	given SPI controller.
344  *	SPI slaves, and are numbered from zero to num_chipselects.
345  *	each slave has a chipselect signal, but it's common that not
346  *	every chipselect is connected to a slave.
347  * @dma_alignment: SPI controller constraint on DMA buffers alignment.
352  *	supported. If set, the SPI core will reject any transfer with an
358  * @slave: indicates that this is an SPI slave controller
359  * @devm_allocated: whether the allocation of this struct is devres-managed
366  * @bus_lock_spinlock: spinlock for SPI bus locking
368  * @bus_lock_flag: indicates that the SPI bus is locked for exclusive use
370  *	device's SPI controller; protocol code may call this.  This
374  * @set_cs_timing: optional hook for SPI devices to request SPI master
378  * @cleanup: frees controller-specific state
388  * @cur_msg: the currently in-flight message
389  * @cur_msg_completion: a completion for the current in-flight message
397  * @last_cs: the last chip_select that is recorded by set_cs, -1 on non chip
427  *                  - return 0 if the transfer is finished,
428  *                  - return 1 if the transfer is still in progress. When
437  * @mem_ops: optimized/dedicated operations for interactions with SPI memory.
442  * @slave_abort: abort the ongoing transfer request on an SPI slave controller
445  *	are not GPIOs (driven by the SPI controller itself).
446  * @use_gpio_descriptors: Turns on the code in the SPI core to parse and grab
447  *	GPIO descriptors. This will fill in @cs_gpiods and SPI devices will have
450  *	fill in this field with the first unused native CS, to be used by SPI
458  * @dummy_rx: dummy receive buffer for full-duplex devices
459  * @dummy_tx: dummy transmit buffer for full-duplex devices
464  *	time snapshot in @spi_transfer->ptp_sts as close as possible to the
465  *	moment in time when @spi_transfer->ptp_sts_word_pre and
466  *	@spi_transfer->ptp_sts_word_post were transmitted.
467  *	If the driver does not set this, the SPI core takes the snapshot as
468  *	close to the driver hand-over as possible.
476  * Each SPI controller can communicate with one or more @spi_device
482  * The driver for an SPI controller manages access to those devices through
484  * an SPI slave device.  For each such message it queues, it calls the
493 	 * board-specific.  usually that simplifies to being SOC-specific.
494 	 * example:  one SOC has three SPI controllers, numbered 0..2,
495 	 * and one board's schematics might show it using SPI-2.  software
501 	 * might use board-specific GPIOs.
505 	/* Some SPI controllers pose alignment requirements on DMAable
518 #define SPI_BPW_MASK(bits) BIT((bits) - 1)
519 #define SPI_BPW_RANGE_MASK(min, max) GENMASK((max) - 1, (min) - 1)
533 #define SPI_MASTER_GPIO_SS		BIT(5)	/* GPIO CS must select slave */
535 	/* Flag indicating if the allocation of this struct is devres-managed */
538 	/* Flag indicating this is an SPI slave controller */
539 	bool			slave;  member
545 	size_t (*max_transfer_size)(struct spi_device *spi);
546 	size_t (*max_message_size)(struct spi_device *spi);
554 	/* Lock and mutex for SPI bus locking */
558 	/* Flag indicating that the SPI bus is locked for exclusive use */
561 	/* Setup mode and clock, etc (spi driver may call many times).
567 	int			(*setup)(struct spi_device *spi);
570 	 * set_cs_timing() method is for SPI controllers that supports
573 	 * This hook allows SPI client drivers to request SPI controllers
577 	int (*set_cs_timing)(struct spi_device *spi);
583 	 * + For now there's no remove-from-queue operation, or
595 	 * + The message transfers use clock and SPI mode parameters
598 	int			(*transfer)(struct spi_device *spi,
602 	void			(*cleanup)(struct spi_device *spi);
612 					   struct spi_device *spi,
622 	 * Over time we expect SPI drivers to be phased over to this API.
658 	void (*set_cs)(struct spi_device *spi, bool enable);
659 	int (*transfer_one)(struct spi_controller *ctlr, struct spi_device *spi,
664 	/* Optimized handlers for SPI memory-like operations. */
688 	 * Driver sets this field to indicate it is able to snapshot SPI
703 	return dev_get_drvdata(&ctlr->dev);  in spi_controller_get_devdata()
709 	dev_set_drvdata(&ctlr->dev, data);  in spi_controller_set_devdata()
714 	if (!ctlr || !get_device(&ctlr->dev))  in spi_controller_get()
722 		put_device(&ctlr->dev);  in spi_controller_put()
727 	return IS_ENABLED(CONFIG_SPI_SLAVE) && ctlr->slave;  in spi_controller_is_slave()
747 /* The spi driver core manages memory for the spi_controller classdev */
749 						unsigned int size, bool slave);
768 						   bool slave);
798  * SPI resource management while processing a SPI message
806  * struct spi_res - spi resource management structure
809  * @data:    extra data allocated for the specific use-case
811  * this is based on ideas from devres, but focused on life-cycle
820 /*---------------------------------------------------------------------------*/
823  * I/O INTERFACE between SPI controller and protocol drivers
831  * pointer.  (This is unlike most types of I/O API, because SPI hardware
840  * struct spi_transfer - a read/write buffer pair
841  * @tx_buf: data to be written (dma-safe memory), or NULL
842  * @rx_buf: data to be read (dma-safe memory), or NULL
864  * @effective_speed_hz: the effective SCK-speed that was used to
865  *      transfer this transfer. Set to 0 if the spi bus driver does
871  *	within @tx_buf for which the SPI device is requesting that the time
872  *	snapshot for this transfer begins. Upon completing the SPI transfer,
881  *	purposefully (instead of setting to spi_transfer->len - 1) to denote
882  *	that a transfer-level snapshot taken from within the driver may still
884  * @ptp_sts: Pointer to a memory location held by the SPI slave device where a
889  *	The timestamp must represent the time at which the SPI slave device has
894  * @error: Error status logged by spi controller driver.
896  * SPI transfers always write the same number of bytes as they read.
909  * In-memory data values are always in native CPU byte order, translated
910  * from the wire byte order (big-endian except with SPI_LSB_FIRST).  So
914  * When the word size of the SPI transfer is not a power-of-two multiple
915  * of eight bits, those in-memory words include extra bits.  In-memory
916  * words are always seen by protocol drivers as right-justified, so the
919  * All SPI transfers start with the relevant chipselect active.  Normally
930  * stay selected until the next transfer.  On multi-device SPI busses
939  * When SPI can transfer in 1x,2x or 4x. It can get this transfer information
940  * from device through @tx_nbits and @rx_nbits. In Bi-direction, these
946  * Zero-initialize every field you don't set up explicitly, to
954 	 *   spi_message.is_dma_mapped reports a pre-existing mapping
995  * struct spi_message - one multi-segment SPI transaction
997  * @spi: SPI device to which the transaction is queued
1008  * @resources: for resource management when the spi message is processed
1013  * in the sense that no other spi_message may use that SPI bus until that
1021  * Zero-initialize every field you don't set up explicitly, to
1028 	struct spi_device	*spi;  member
1037 	 * Some controller drivers (message-at-a-time queue processing)
1039 	 * others (with multi-message pipelines) could need a flag to
1057 	/* List of spi_res reources when the spi message is processed */
1066 	INIT_LIST_HEAD(&m->transfers);  in spi_message_init_no_memset()
1067 	INIT_LIST_HEAD(&m->resources);  in spi_message_init_no_memset()
1079 	list_add_tail(&t->transfer_list, &m->transfers);  in spi_message_add_tail()
1085 	list_del(&t->transfer_list);  in spi_transfer_del()
1091 	return spi_delay_exec(&t->delay, t);  in spi_transfer_delay_exec()
1095  * spi_message_init_with_transfers - Initialize spi_message and append transfers
1097  * @xfers: An array of spi transfers
1141 extern int spi_setup(struct spi_device *spi);
1142 extern int spi_async(struct spi_device *spi, struct spi_message *message);
1143 extern int spi_slave_abort(struct spi_device *spi);
1146 spi_max_message_size(struct spi_device *spi)  in spi_max_message_size()  argument
1148 	struct spi_controller *ctlr = spi->controller;  in spi_max_message_size()
1150 	if (!ctlr->max_message_size)  in spi_max_message_size()
1152 	return ctlr->max_message_size(spi);  in spi_max_message_size()
1156 spi_max_transfer_size(struct spi_device *spi)  in spi_max_transfer_size()  argument
1158 	struct spi_controller *ctlr = spi->controller;  in spi_max_transfer_size()
1160 	size_t msg_max = spi_max_message_size(spi);  in spi_max_transfer_size()
1162 	if (ctlr->max_transfer_size)  in spi_max_transfer_size()
1163 		tr_max = ctlr->max_transfer_size(spi);  in spi_max_transfer_size()
1170  * spi_is_bpw_supported - Check if bits per word is supported
1171  * @spi: SPI device
1174  * This function checks to see if the SPI controller supports @bpw.
1179 static inline bool spi_is_bpw_supported(struct spi_device *spi, u32 bpw)  in spi_is_bpw_supported()  argument
1181 	u32 bpw_mask = spi->master->bits_per_word_mask;  in spi_is_bpw_supported()
1189 /*---------------------------------------------------------------------------*/
1191 /* SPI transfer replacement methods which make use of spi_res */
1198  * struct spi_replaced_transfers - structure describing the spi_transfer
1207  *                      are to get re-inserted
1209  * @inserted_transfers: array of spi_transfers of array-size @inserted,
1225 /*---------------------------------------------------------------------------*/
1227 /* SPI transfer transformation methods */
1234 /*---------------------------------------------------------------------------*/
1236 /* All these synchronous SPI transfer routines are utilities layered
1241 extern int spi_sync(struct spi_device *spi, struct spi_message *message);
1242 extern int spi_sync_locked(struct spi_device *spi, struct spi_message *message);
1247  * spi_sync_transfer - synchronous SPI data transfer
1248  * @spi: device with which data will be exchanged
1253  * Does a synchronous SPI data transfer of the given spi_transfer array.
1260 spi_sync_transfer(struct spi_device *spi, struct spi_transfer *xfers,  in spi_sync_transfer()  argument
1267 	return spi_sync(spi, &msg);  in spi_sync_transfer()
1271  * spi_write - SPI synchronous write
1272  * @spi: device to which data will be written
1283 spi_write(struct spi_device *spi, const void *buf, size_t len)  in spi_write()  argument
1290 	return spi_sync_transfer(spi, &t, 1);  in spi_write()
1294  * spi_read - SPI synchronous read
1295  * @spi: device from which data will be read
1306 spi_read(struct spi_device *spi, void *buf, size_t len)  in spi_read()  argument
1313 	return spi_sync_transfer(spi, &t, 1);  in spi_read()
1317 extern int spi_write_then_read(struct spi_device *spi,
1322  * spi_w8r8 - SPI synchronous 8 bit write followed by 8 bit read
1323  * @spi: device with which data will be exchanged
1332 static inline ssize_t spi_w8r8(struct spi_device *spi, u8 cmd)  in spi_w8r8()  argument
1337 	status = spi_write_then_read(spi, &cmd, 1, &result, 1);  in spi_w8r8()
1344  * spi_w8r16 - SPI synchronous 8 bit write followed by 16 bit read
1345  * @spi: device with which data will be exchanged
1349  * The number is returned in wire-order, which is at least sometimes
1350  * big-endian.
1357 static inline ssize_t spi_w8r16(struct spi_device *spi, u8 cmd)  in spi_w8r16()  argument
1362 	status = spi_write_then_read(spi, &cmd, 1, &result, 2);  in spi_w8r16()
1369  * spi_w8r16be - SPI synchronous 8 bit write followed by 16 bit big-endian read
1370  * @spi: device with which data will be exchanged
1375  * convert the read 16 bit data word from big-endian to native endianness.
1382 static inline ssize_t spi_w8r16be(struct spi_device *spi, u8 cmd)  in spi_w8r16be()  argument
1388 	status = spi_write_then_read(spi, &cmd, 1, &result, 2);  in spi_w8r16be()
1395 /*---------------------------------------------------------------------------*/
1398  * INTERFACE between board init code and SPI infrastructure.
1400  * No SPI driver ever sees these SPI device table segments, but
1401  * it's how the SPI core (or adapters that get hotplugged) grows
1404  * As a rule, SPI devices can't be probed.  Instead, board init code
1408  * parport adapters, or microcontrollers acting as USB-to-SPI bridges.
1412  * struct spi_board_info - board-specific template for a SPI device
1415  *	data stored there is driver-specific.
1421  *	from the chip datasheet and board-specific signal quality issues.
1430  * When adding new SPI devices to the device tree, these structures serve
1436  * be stored in tables of board-specific device descriptors, which are
1478 	 *  - quirks like clock rate mattering when not selected
1486 /* Board init code may ignore whether SPI is configured or not */
1507 spi_add_device(struct spi_device *spi);
1512 extern void spi_unregister_device(struct spi_device *spi);
1520 	return list_is_last(&xfer->transfer_list, &ctlr->cur_msg->transfers);  in spi_transfer_is_last()