linux/spi/spi.h

1 /* SPDX-License-Identifier: GPL-2.0-or-later
26  * INTERFACES between SPI master-side drivers and SPI slave protocol handlers,
32  * struct spi_statistics - statistics for spi transfers
35  * @messages:      number of spi-messages handled
86 		spin_lock_irqsave(&(stats)->lock, flags);	\
87 		(stats)->field += count;			\
88 		spin_unlock_irqrestore(&(stats)->lock, flags);	\
95  * struct spi_delay - SPI delay information
111  * struct spi_device - Controller side proxy for an SPI slave device
119  * @mode: The spi mode defines how data is clocked out and in.
125  *	like eight or 12 bits are common.  In-memory wordsizes are
134  * @controller_data: Board-specific definitions for controller, such as
141  * @cs_gpio: LEGACY: gpio number of the chipselect line (optional, -ENOENT when
176 #define	SPI_LSB_FIRST	0x08			/* per-word bits-on-wire */
196 	struct spi_delay	word_delay; /* inter-word delay */
207 	 *  - memory packing (12 bit samples into low bits, others zeroed)
208 	 *  - priority
209 	 *  - chipselect delays
210 	 *  - ...
222 	return (spi && get_device(&spi->dev)) ? spi : NULL;  in spi_dev_get()
228 		put_device(&spi->dev);  in spi_dev_put()
234 	return spi->controller_state;  in spi_get_ctldata()
239 	spi->controller_state = state;  in spi_set_ctldata()
246 	dev_set_drvdata(&spi->dev, data);  in spi_set_drvdata()
251 	return dev_get_drvdata(&spi->dev);  in spi_get_drvdata()
258  * struct spi_driver - Host side "protocol" driver
300  * spi_unregister_driver - reverse effect of spi_register_driver
307 		driver_unregister(&sdrv->driver);  in spi_unregister_driver()
315  * module_spi_driver() - Helper macro for registering a SPI driver
327  * struct spi_controller - interface to SPI master or slave controller
330  * @bus_num: board-specific (and often SOC-specific) identifier for a
348  * @max_transfer_size: function that returns the max transfer size for
350  * @max_message_size: function that returns the max message size for
365  * @cleanup: frees controller-specific state
373  * @cur_msg: the currently in-flight message
375  *                    in-flight message
406  *                  - return 0 if the transfer is finished,
407  *                  - return 1 if the transfer is still in progress. When
427  *	CS number. Any individual value may be -ENOENT for CS lines that
446  * @dummy_rx: dummy receive buffer for full-duplex devices
447  * @dummy_tx: dummy transmit buffer for full-duplex devices
452  *	time snapshot in @spi_transfer->ptp_sts as close as possible to the
453  *	moment in time when @spi_transfer->ptp_sts_word_pre and
454  *	@spi_transfer->ptp_sts_word_post were transmitted.
456  *	close to the driver hand-over as possible.
478 	 * board-specific.  usually that simplifies to being SOC-specific.
480 	 * and one board's schematics might show it using SPI-2.  software
486 	 * might use board-specific GPIOs.
503 #define SPI_BPW_MASK(bits) BIT((bits) - 1)
504 #define SPI_BPW_RANGE_MASK(min, max) GENMASK((max) - 1, (min) - 1)  argument
563 	 * + For now there's no remove-from-queue operation, or
640 	/* Optimized handlers for SPI memory-like operations. */
665 	/* DMA channels for use with core dmaengine helpers */
690 	return dev_get_drvdata(&ctlr->dev);  in spi_controller_get_devdata()
696 	dev_set_drvdata(&ctlr->dev, data);  in spi_controller_set_devdata()
701 	if (!ctlr || !get_device(&ctlr->dev))  in spi_controller_get()
709 		put_device(&ctlr->dev);  in spi_controller_put()
714 	return IS_ENABLED(CONFIG_SPI_SLAVE) && ctlr->slave;  in spi_controller_is_slave()
788  * struct spi_res - spi resource management structure
791  * @data:    extra data allocated for the specific use-case
793  * this is based on ideas from devres, but focused on life-cycle
811 /*---------------------------------------------------------------------------*/
831  * struct spi_transfer - a read/write buffer pair
832  * @tx_buf: data to be written (dma-safe memory), or NULL
833  * @rx_buf: data to be read (dma-safe memory), or NULL
856  * @effective_speed_hz: the effective SCK-speed that was used to
873  *	purposefully (instead of setting to spi_transfer->len - 1) to denote
874  *	that a transfer-level snapshot taken from within the driver may still
901  * In-memory data values are always in native CPU byte order, translated
902  * from the wire byte order (big-endian except with SPI_LSB_FIRST).  So
906  * When the word size of the SPI transfer is not a power-of-two multiple
907  * of eight bits, those in-memory words include extra bits.  In-memory
908  * words are always seen by protocol drivers as right-justified, so the
922  * stay selected until the next transfer.  On multi-device SPI busses
932  * from device through @tx_nbits and @rx_nbits. In Bi-direction, these
938  * Zero-initialize every field you don't set up explicitly, to
946 	 *   spi_message.is_dma_mapped reports a pre-existing mapping
988  * struct spi_message - one multi-segment SPI transaction
1013  * Zero-initialize every field you don't set up explicitly, to
1029 	 * Some controller drivers (message-at-a-time queue processing)
1031 	 * others (with multi-message pipelines) could need a flag to
1057 	INIT_LIST_HEAD(&m->transfers);  in spi_message_init_no_memset()
1058 	INIT_LIST_HEAD(&m->resources);  in spi_message_init_no_memset()
1070 	list_add_tail(&t->transfer_list, &m->transfers);  in spi_message_add_tail()
1076 	list_del(&t->transfer_list);  in spi_transfer_del()
1084 	if (t->delay_usecs) {  in spi_transfer_delay_exec()
1085 		d.value = t->delay_usecs;  in spi_transfer_delay_exec()
1090 	return spi_delay_exec(&t->delay, t);  in spi_transfer_delay_exec()
1094  * spi_message_init_with_transfers - Initialize spi_message and append transfers
1154 	struct spi_controller *ctlr = spi->controller;  in spi_max_message_size()
1156 	if (!ctlr->max_message_size)  in spi_max_message_size()
1158 	return ctlr->max_message_size(spi);  in spi_max_message_size()
1164 	struct spi_controller *ctlr = spi->controller;  in spi_max_transfer_size()
1168 	if (ctlr->max_transfer_size)  in spi_max_transfer_size()
1169 		tr_max = ctlr->max_transfer_size(spi);  in spi_max_transfer_size()
1176  * spi_is_bpw_supported - Check if bits per word is supported
1187 	u32 bpw_mask = spi->master->bits_per_word_mask;  in spi_is_bpw_supported()
1195 /*---------------------------------------------------------------------------*/
1204  * struct spi_replaced_transfers - structure describing the spi_transfer
1213  *                      are to get re-inserted
1215  * @inserted_transfers: array of spi_transfers of array-size @inserted,
1240 /*---------------------------------------------------------------------------*/
1249 /*---------------------------------------------------------------------------*/
1262  * spi_sync_transfer - synchronous SPI data transfer
1286  * spi_write - SPI synchronous write
1309  * spi_read - SPI synchronous read
1337  * spi_w8r8 - SPI synchronous 8 bit write followed by 8 bit read
1359  * spi_w8r16 - SPI synchronous 8 bit write followed by 16 bit read
1364  * The number is returned in wire-order, which is at least sometimes
1365  * big-endian.
1384  * spi_w8r16be - SPI synchronous 8 bit write followed by 16 bit big-endian read
1390  * convert the read 16 bit data word from big-endian to native endianness.
1410 /*---------------------------------------------------------------------------*/
1423  * parport adapters, or microcontrollers acting as USB-to-SPI bridges.
1427  * struct spi_board_info - board-specific template for a SPI device
1430  *	data stored there is driver-specific.
1436  *	from the chip datasheet and board-specific signal quality issues.
1451  * be stored in tables of board-specific device descriptors, which are
1496 	 *  - quirks like clock rate mattering when not selected
1538 	return list_is_last(&xfer->transfer_list, &ctlr->cur_msg->transfers);  in spi_transfer_is_last()