1 /* SPDX-License-Identifier: GPL-2.0-or-later
3 * Copyright (C) 2005 David Brownell
9 #include <linux/bits.h>
10 #include <linux/device.h>
11 #include <linux/mod_devicetable.h>
12 #include <linux/slab.h>
13 #include <linux/kthread.h>
14 #include <linux/completion.h>
15 #include <linux/scatterlist.h>
16 #include <linux/gpio/consumer.h>
18 #include <uapi/linux/spi/spi.h>
19 #include <linux/acpi.h>
23 struct ptp_system_timestamp;
24 struct spi_controller;
26 struct spi_controller_mem_ops;
27 struct spi_controller_mem_caps;
30 * INTERFACES between SPI master-side drivers and SPI slave protocol handlers,
31 * and SPI infrastructure.
33 extern struct bus_type spi_bus_type;
36 * struct spi_statistics - statistics for spi transfers
37 * @lock: lock protecting this structure
39 * @messages: number of spi-messages handled
40 * @transfers: number of spi_transfers handled
41 * @errors: number of errors during spi_transfer
42 * @timedout: number of timeouts during spi_transfer
44 * @spi_sync: number of times spi_sync is used
45 * @spi_sync_immediate:
46 * number of times spi_sync is executed immediately
47 * in calling context without queuing and scheduling
48 * @spi_async: number of times spi_async is used
50 * @bytes: number of bytes transferred to/from device
51 * @bytes_tx: number of bytes sent to device
52 * @bytes_rx: number of bytes received from device
54 * @transfer_bytes_histo:
55 * transfer bytes histogramm
57 * @transfers_split_maxsize:
58 * number of transfers that have been split because of
61 struct spi_statistics {
62 spinlock_t lock; /* lock for the whole structure */
64 unsigned long messages;
65 unsigned long transfers;
67 unsigned long timedout;
69 unsigned long spi_sync;
70 unsigned long spi_sync_immediate;
71 unsigned long spi_async;
73 unsigned long long bytes;
74 unsigned long long bytes_rx;
75 unsigned long long bytes_tx;
77 #define SPI_STATISTICS_HISTO_SIZE 17
78 unsigned long transfer_bytes_histo[SPI_STATISTICS_HISTO_SIZE];
80 unsigned long transfers_split_maxsize;
83 #define SPI_STATISTICS_ADD_TO_FIELD(stats, field, count) \
85 unsigned long flags; \
86 spin_lock_irqsave(&(stats)->lock, flags); \
87 (stats)->field += count; \
88 spin_unlock_irqrestore(&(stats)->lock, flags); \
91 #define SPI_STATISTICS_INCREMENT_FIELD(stats, field) \
92 SPI_STATISTICS_ADD_TO_FIELD(stats, field, 1)
95 * struct spi_delay - SPI delay information
96 * @value: Value for the delay
97 * @unit: Unit for the delay
100 #define SPI_DELAY_UNIT_USECS 0
101 #define SPI_DELAY_UNIT_NSECS 1
102 #define SPI_DELAY_UNIT_SCK 2
107 extern int spi_delay_to_ns(struct spi_delay *_delay, struct spi_transfer *xfer);
108 extern int spi_delay_exec(struct spi_delay *_delay, struct spi_transfer *xfer);
111 * struct spi_device - Controller side proxy for an SPI slave device
112 * @dev: Driver model representation of the device.
113 * @controller: SPI controller used with the device.
114 * @master: Copy of controller, for backwards compatibility.
115 * @max_speed_hz: Maximum clock rate to be used with this chip
116 * (on this board); may be changed by the device's driver.
117 * The spi_transfer.speed_hz can override this for each transfer.
118 * @chip_select: Chipselect, distinguishing chips handled by @controller.
119 * @mode: The spi mode defines how data is clocked out and in.
120 * This may be changed by the device's driver.
121 * The "active low" default for chipselect mode can be overridden
122 * (by specifying SPI_CS_HIGH) as can the "MSB first" default for
123 * each word in a transfer (by specifying SPI_LSB_FIRST).
124 * @bits_per_word: Data transfers involve one or more words; word sizes
125 * like eight or 12 bits are common. In-memory wordsizes are
126 * powers of two bytes (e.g. 20 bit samples use 32 bits).
127 * This may be changed by the device's driver, or left at the
128 * default (0) indicating protocol words are eight bit bytes.
129 * The spi_transfer.bits_per_word can override this for each transfer.
130 * @rt: Make the pump thread real time priority.
131 * @irq: Negative, or the number passed to request_irq() to receive
132 * interrupts from this device.
133 * @controller_state: Controller's runtime state
134 * @controller_data: Board-specific definitions for controller, such as
135 * FIFO initialization parameters; from board_info.controller_data
136 * @modalias: Name of the driver to use with this device, or an alias
137 * for that name. This appears in the sysfs "modalias" attribute
138 * for driver coldplugging, and in uevents used for hotplugging
139 * @driver_override: If the name of a driver is written to this attribute, then
140 * the device will bind to the named driver and only the named driver.
141 * Do not set directly, because core frees it; use driver_set_override() to
143 * @cs_gpiod: gpio descriptor of the chipselect line (optional, NULL when
144 * not using a GPIO line)
145 * @word_delay: delay to be inserted between consecutive
146 * words of a transfer
147 * @cs_setup: delay to be introduced by the controller after CS is asserted
148 * @cs_hold: delay to be introduced by the controller before CS is deasserted
149 * @cs_inactive: delay to be introduced by the controller after CS is
150 * deasserted. If @cs_change_delay is used from @spi_transfer, then the
151 * two delays will be added up.
152 * @statistics: statistics for the spi_device
154 * A @spi_device is used to interchange data between an SPI slave
155 * (usually a discrete chip) and CPU memory.
157 * In @dev, the platform_data is used to hold information about this
158 * device that's meaningful to the device's protocol driver, but not
159 * to its controller. One example might be an identifier for a chip
160 * variant with slightly different functionality; another might be
161 * information about how this particular board wires the chip's pins.
165 struct spi_controller *controller;
166 struct spi_controller *master; /* compatibility layer */
171 #define SPI_NO_TX BIT(31) /* no transmit wire */
172 #define SPI_NO_RX BIT(30) /* no receive wire */
174 * All bits defined above should be covered by SPI_MODE_KERNEL_MASK.
175 * The SPI_MODE_KERNEL_MASK has the SPI_MODE_USER_MASK counterpart,
176 * which is defined in 'include/uapi/linux/spi/spi.h'.
177 * The bits defined here are from bit 31 downwards, while in
178 * SPI_MODE_USER_MASK are from 0 upwards.
179 * These bits must not overlap. A static assert check should make sure of that.
180 * If adding extra bits, make sure to decrease the bit index below as well.
182 #define SPI_MODE_KERNEL_MASK (~(BIT(30) - 1))
185 void *controller_state;
186 void *controller_data;
187 char modalias[SPI_NAME_SIZE];
188 const char *driver_override;
189 struct gpio_desc *cs_gpiod; /* chip select gpio desc */
190 struct spi_delay word_delay; /* inter-word delay */
192 struct spi_delay cs_setup;
193 struct spi_delay cs_hold;
194 struct spi_delay cs_inactive;
197 struct spi_statistics statistics;
200 * likely need more hooks for more protocol options affecting how
201 * the controller talks to each chip, like:
202 * - memory packing (12 bit samples into low bits, others zeroed)
204 * - chipselect delays
209 /* Make sure that SPI_MODE_KERNEL_MASK & SPI_MODE_USER_MASK don't overlap */
210 static_assert((SPI_MODE_KERNEL_MASK & SPI_MODE_USER_MASK) == 0,
211 "SPI_MODE_USER_MASK & SPI_MODE_KERNEL_MASK must not overlap");
213 static inline struct spi_device *to_spi_device(struct device *dev)
215 return dev ? container_of(dev, struct spi_device, dev) : NULL;
218 /* most drivers won't need to care about device refcounting */
219 static inline struct spi_device *spi_dev_get(struct spi_device *spi)
221 return (spi && get_device(&spi->dev)) ? spi : NULL;
224 static inline void spi_dev_put(struct spi_device *spi)
227 put_device(&spi->dev);
230 /* ctldata is for the bus_controller driver's runtime state */
231 static inline void *spi_get_ctldata(struct spi_device *spi)
233 return spi->controller_state;
236 static inline void spi_set_ctldata(struct spi_device *spi, void *state)
238 spi->controller_state = state;
241 /* device driver data */
243 static inline void spi_set_drvdata(struct spi_device *spi, void *data)
245 dev_set_drvdata(&spi->dev, data);
248 static inline void *spi_get_drvdata(struct spi_device *spi)
250 return dev_get_drvdata(&spi->dev);
256 * struct spi_driver - Host side "protocol" driver
257 * @id_table: List of SPI devices supported by this driver
258 * @probe: Binds this driver to the spi device. Drivers can verify
259 * that the device is actually present, and may need to configure
260 * characteristics (such as bits_per_word) which weren't needed for
261 * the initial configuration done during system setup.
262 * @remove: Unbinds this driver from the spi device
263 * @shutdown: Standard shutdown callback used during system state
264 * transitions such as powerdown/halt and kexec
265 * @driver: SPI device drivers should initialize the name and owner
266 * field of this structure.
268 * This represents the kind of device driver that uses SPI messages to
269 * interact with the hardware at the other end of a SPI link. It's called
270 * a "protocol" driver because it works through messages rather than talking
271 * directly to SPI hardware (which is what the underlying SPI controller
272 * driver does to pass those messages). These protocols are defined in the
273 * specification for the device(s) supported by the driver.
275 * As a rule, those device protocols represent the lowest level interface
276 * supported by a driver, and it will support upper level interfaces too.
277 * Examples of such upper levels include frameworks like MTD, networking,
278 * MMC, RTC, filesystem character device nodes, and hardware monitoring.
281 const struct spi_device_id *id_table;
282 int (*probe)(struct spi_device *spi);
283 void (*remove)(struct spi_device *spi);
284 void (*shutdown)(struct spi_device *spi);
285 struct device_driver driver;
288 static inline struct spi_driver *to_spi_driver(struct device_driver *drv)
290 return drv ? container_of(drv, struct spi_driver, driver) : NULL;
293 extern int __spi_register_driver(struct module *owner, struct spi_driver *sdrv);
296 * spi_unregister_driver - reverse effect of spi_register_driver
297 * @sdrv: the driver to unregister
300 static inline void spi_unregister_driver(struct spi_driver *sdrv)
303 driver_unregister(&sdrv->driver);
306 extern struct spi_device *spi_new_ancillary_device(struct spi_device *spi, u8 chip_select);
308 /* use a define to avoid include chaining to get THIS_MODULE */
309 #define spi_register_driver(driver) \
310 __spi_register_driver(THIS_MODULE, driver)
313 * module_spi_driver() - Helper macro for registering a SPI driver
314 * @__spi_driver: spi_driver struct
316 * Helper macro for SPI drivers which do not do anything special in module
317 * init/exit. This eliminates a lot of boilerplate. Each module may only
318 * use this macro once, and calling it replaces module_init() and module_exit()
320 #define module_spi_driver(__spi_driver) \
321 module_driver(__spi_driver, spi_register_driver, \
322 spi_unregister_driver)
325 * struct spi_controller - interface to SPI master or slave controller
326 * @dev: device interface to this driver
327 * @list: link with the global spi_controller list
328 * @bus_num: board-specific (and often SOC-specific) identifier for a
329 * given SPI controller.
330 * @num_chipselect: chipselects are used to distinguish individual
331 * SPI slaves, and are numbered from zero to num_chipselects.
332 * each slave has a chipselect signal, but it's common that not
333 * every chipselect is connected to a slave.
334 * @dma_alignment: SPI controller constraint on DMA buffers alignment.
335 * @mode_bits: flags understood by this controller driver
336 * @buswidth_override_bits: flags to override for this controller driver
337 * @bits_per_word_mask: A mask indicating which values of bits_per_word are
338 * supported by the driver. Bit n indicates that a bits_per_word n+1 is
339 * supported. If set, the SPI core will reject any transfer with an
340 * unsupported bits_per_word. If not set, this value is simply ignored,
341 * and it's up to the individual driver to perform any validation.
342 * @min_speed_hz: Lowest supported transfer speed
343 * @max_speed_hz: Highest supported transfer speed
344 * @flags: other constraints relevant to this driver
345 * @slave: indicates that this is an SPI slave controller
346 * @devm_allocated: whether the allocation of this struct is devres-managed
347 * @max_transfer_size: function that returns the max transfer size for
348 * a &spi_device; may be %NULL, so the default %SIZE_MAX will be used.
349 * @max_message_size: function that returns the max message size for
350 * a &spi_device; may be %NULL, so the default %SIZE_MAX will be used.
351 * @io_mutex: mutex for physical bus access
352 * @add_lock: mutex to avoid adding devices to the same chipselect
353 * @bus_lock_spinlock: spinlock for SPI bus locking
354 * @bus_lock_mutex: mutex for exclusion of multiple callers
355 * @bus_lock_flag: indicates that the SPI bus is locked for exclusive use
356 * @setup: updates the device mode and clocking records used by a
357 * device's SPI controller; protocol code may call this. This
358 * must fail if an unrecognized or unsupported mode is requested.
359 * It's always safe to call this unless transfers are pending on
360 * the device whose settings are being modified.
361 * @set_cs_timing: optional hook for SPI devices to request SPI master
362 * controller for configuring specific CS setup time, hold time and inactive
363 * delay interms of clock counts
364 * @transfer: adds a message to the controller's transfer queue.
365 * @cleanup: frees controller-specific state
366 * @can_dma: determine whether this controller supports DMA
367 * @dma_map_dev: device which can be used for DMA mapping
368 * @queued: whether this controller is providing an internal message queue
369 * @kworker: pointer to thread struct for message pump
370 * @pump_messages: work struct for scheduling work to the message pump
371 * @queue_lock: spinlock to syncronise access to message queue
372 * @queue: message queue
373 * @idling: the device is entering idle state
374 * @cur_msg: the currently in-flight message
375 * @cur_msg_prepared: spi_prepare_message was called for the currently
377 * @cur_msg_mapped: message has been mapped for DMA
378 * @last_cs: the last chip_select that is recorded by set_cs, -1 on non chip
380 * @last_cs_mode_high: was (mode & SPI_CS_HIGH) true on the last call to set_cs.
381 * @xfer_completion: used by core transfer_one_message()
382 * @busy: message pump is busy
383 * @running: message pump is running
384 * @rt: whether this queue is set to run as a realtime task
385 * @auto_runtime_pm: the core should ensure a runtime PM reference is held
386 * while the hardware is prepared, using the parent
387 * device for the spidev
388 * @max_dma_len: Maximum length of a DMA transfer for the device.
389 * @prepare_transfer_hardware: a message will soon arrive from the queue
390 * so the subsystem requests the driver to prepare the transfer hardware
391 * by issuing this call
392 * @transfer_one_message: the subsystem calls the driver to transfer a single
393 * message while queuing transfers that arrive in the meantime. When the
394 * driver is finished with this message, it must call
395 * spi_finalize_current_message() so the subsystem can issue the next
397 * @unprepare_transfer_hardware: there are currently no more messages on the
398 * queue so the subsystem notifies the driver that it may relax the
399 * hardware by issuing this call
401 * @set_cs: set the logic level of the chip select line. May be called
402 * from interrupt context.
403 * @prepare_message: set up the controller to transfer a single message,
404 * for example doing DMA mapping. Called from threaded
406 * @transfer_one: transfer a single spi_transfer.
408 * - return 0 if the transfer is finished,
409 * - return 1 if the transfer is still in progress. When
410 * the driver is finished with this transfer it must
411 * call spi_finalize_current_transfer() so the subsystem
412 * can issue the next transfer. Note: transfer_one and
413 * transfer_one_message are mutually exclusive; when both
414 * are set, the generic subsystem does not call your
415 * transfer_one callback.
416 * @handle_err: the subsystem calls the driver to handle an error that occurs
417 * in the generic implementation of transfer_one_message().
418 * @mem_ops: optimized/dedicated operations for interactions with SPI memory.
419 * This field is optional and should only be implemented if the
420 * controller has native support for memory like operations.
421 * @mem_caps: controller capabilities for the handling of memory operations.
422 * @unprepare_message: undo any work done by prepare_message().
423 * @slave_abort: abort the ongoing transfer request on an SPI slave controller
424 * @cs_gpiods: Array of GPIO descs to use as chip select lines; one per CS
425 * number. Any individual value may be NULL for CS lines that
426 * are not GPIOs (driven by the SPI controller itself).
427 * @use_gpio_descriptors: Turns on the code in the SPI core to parse and grab
428 * GPIO descriptors. This will fill in @cs_gpiods and SPI devices will have
429 * the cs_gpiod assigned if a GPIO line is found for the chipselect.
430 * @unused_native_cs: When cs_gpiods is used, spi_register_controller() will
431 * fill in this field with the first unused native CS, to be used by SPI
432 * controller drivers that need to drive a native CS when using GPIO CS.
433 * @max_native_cs: When cs_gpiods is used, and this field is filled in,
434 * spi_register_controller() will validate all native CS (including the
435 * unused native CS) against this value.
436 * @statistics: statistics for the spi_controller
437 * @dma_tx: DMA transmit channel
438 * @dma_rx: DMA receive channel
439 * @dummy_rx: dummy receive buffer for full-duplex devices
440 * @dummy_tx: dummy transmit buffer for full-duplex devices
441 * @fw_translate_cs: If the boot firmware uses different numbering scheme
442 * what Linux expects, this optional hook can be used to translate
444 * @ptp_sts_supported: If the driver sets this to true, it must provide a
445 * time snapshot in @spi_transfer->ptp_sts as close as possible to the
446 * moment in time when @spi_transfer->ptp_sts_word_pre and
447 * @spi_transfer->ptp_sts_word_post were transmitted.
448 * If the driver does not set this, the SPI core takes the snapshot as
449 * close to the driver hand-over as possible.
450 * @irq_flags: Interrupt enable state during PTP system timestamping
451 * @fallback: fallback to pio if dma transfer return failure with
452 * SPI_TRANS_FAIL_NO_START.
454 * Each SPI controller can communicate with one or more @spi_device
455 * children. These make a small bus, sharing MOSI, MISO and SCK signals
456 * but not chip select signals. Each device may be configured to use a
457 * different clock rate, since those shared signals are ignored unless
458 * the chip is selected.
460 * The driver for an SPI controller manages access to those devices through
461 * a queue of spi_message transactions, copying data between CPU memory and
462 * an SPI slave device. For each such message it queues, it calls the
463 * message's completion function when the transaction completes.
465 struct spi_controller {
468 struct list_head list;
470 /* other than negative (== assign one dynamically), bus_num is fully
471 * board-specific. usually that simplifies to being SOC-specific.
472 * example: one SOC has three SPI controllers, numbered 0..2,
473 * and one board's schematics might show it using SPI-2. software
474 * would normally use bus_num=2 for that controller.
478 /* chipselects will be integral to many controllers; some others
479 * might use board-specific GPIOs.
483 /* some SPI controllers pose alignment requirements on DMAable
484 * buffers; let protocol drivers know about these requirements.
488 /* spi_device.mode flags understood by this controller driver */
491 /* spi_device.mode flags override flags for this controller */
492 u32 buswidth_override_bits;
494 /* bitmask of supported bits_per_word for transfers */
495 u32 bits_per_word_mask;
496 #define SPI_BPW_MASK(bits) BIT((bits) - 1)
497 #define SPI_BPW_RANGE_MASK(min, max) GENMASK((max) - 1, (min) - 1)
499 /* limits on transfer speed */
503 /* other constraints relevant to this driver */
505 #define SPI_CONTROLLER_HALF_DUPLEX BIT(0) /* can't do full duplex */
506 #define SPI_CONTROLLER_NO_RX BIT(1) /* can't do buffer read */
507 #define SPI_CONTROLLER_NO_TX BIT(2) /* can't do buffer write */
508 #define SPI_CONTROLLER_MUST_RX BIT(3) /* requires rx */
509 #define SPI_CONTROLLER_MUST_TX BIT(4) /* requires tx */
511 #define SPI_MASTER_GPIO_SS BIT(5) /* GPIO CS must select slave */
513 /* flag indicating if the allocation of this struct is devres-managed */
516 /* flag indicating this is an SPI slave controller */
520 * on some hardware transfer / message size may be constrained
521 * the limit may depend on device transfer settings
523 size_t (*max_transfer_size)(struct spi_device *spi);
524 size_t (*max_message_size)(struct spi_device *spi);
527 struct mutex io_mutex;
529 /* Used to avoid adding the same CS twice */
530 struct mutex add_lock;
532 /* lock and mutex for SPI bus locking */
533 spinlock_t bus_lock_spinlock;
534 struct mutex bus_lock_mutex;
536 /* flag indicating that the SPI bus is locked for exclusive use */
539 /* Setup mode and clock, etc (spi driver may call many times).
541 * IMPORTANT: this may be called when transfers to another
542 * device are active. DO NOT UPDATE SHARED REGISTERS in ways
543 * which could break those transfers.
545 int (*setup)(struct spi_device *spi);
548 * set_cs_timing() method is for SPI controllers that supports
549 * configuring CS timing.
551 * This hook allows SPI client drivers to request SPI controllers
552 * to configure specific CS timing through spi_set_cs_timing() after
555 int (*set_cs_timing)(struct spi_device *spi);
557 /* bidirectional bulk transfers
559 * + The transfer() method may not sleep; its main role is
560 * just to add the message to the queue.
561 * + For now there's no remove-from-queue operation, or
562 * any other request management
563 * + To a given spi_device, message queueing is pure fifo
565 * + The controller's main job is to process its message queue,
566 * selecting a chip (for masters), then transferring data
567 * + If there are multiple spi_device children, the i/o queue
568 * arbitration algorithm is unspecified (round robin, fifo,
569 * priority, reservations, preemption, etc)
571 * + Chipselect stays active during the entire message
572 * (unless modified by spi_transfer.cs_change != 0).
573 * + The message transfers use clock and SPI mode parameters
574 * previously established by setup() for this device
576 int (*transfer)(struct spi_device *spi,
577 struct spi_message *mesg);
579 /* called on release() to free memory provided by spi_controller */
580 void (*cleanup)(struct spi_device *spi);
583 * Used to enable core support for DMA handling, if can_dma()
584 * exists and returns true then the transfer will be mapped
585 * prior to transfer_one() being called. The driver should
586 * not modify or store xfer and dma_tx and dma_rx must be set
587 * while the device is prepared.
589 bool (*can_dma)(struct spi_controller *ctlr,
590 struct spi_device *spi,
591 struct spi_transfer *xfer);
592 struct device *dma_map_dev;
595 * These hooks are for drivers that want to use the generic
596 * controller transfer queueing mechanism. If these are used, the
597 * transfer() function above must NOT be specified by the driver.
598 * Over time we expect SPI drivers to be phased over to this API.
601 struct kthread_worker *kworker;
602 struct kthread_work pump_messages;
603 spinlock_t queue_lock;
604 struct list_head queue;
605 struct spi_message *cur_msg;
610 bool auto_runtime_pm;
611 bool cur_msg_prepared;
614 bool last_cs_mode_high;
616 struct completion xfer_completion;
619 int (*prepare_transfer_hardware)(struct spi_controller *ctlr);
620 int (*transfer_one_message)(struct spi_controller *ctlr,
621 struct spi_message *mesg);
622 int (*unprepare_transfer_hardware)(struct spi_controller *ctlr);
623 int (*prepare_message)(struct spi_controller *ctlr,
624 struct spi_message *message);
625 int (*unprepare_message)(struct spi_controller *ctlr,
626 struct spi_message *message);
627 int (*slave_abort)(struct spi_controller *ctlr);
630 * These hooks are for drivers that use a generic implementation
631 * of transfer_one_message() provided by the core.
633 void (*set_cs)(struct spi_device *spi, bool enable);
634 int (*transfer_one)(struct spi_controller *ctlr, struct spi_device *spi,
635 struct spi_transfer *transfer);
636 void (*handle_err)(struct spi_controller *ctlr,
637 struct spi_message *message);
639 /* Optimized handlers for SPI memory-like operations. */
640 const struct spi_controller_mem_ops *mem_ops;
641 const struct spi_controller_mem_caps *mem_caps;
643 /* gpio chip select */
644 struct gpio_desc **cs_gpiods;
645 bool use_gpio_descriptors;
650 struct spi_statistics statistics;
652 /* DMA channels for use with core dmaengine helpers */
653 struct dma_chan *dma_tx;
654 struct dma_chan *dma_rx;
656 /* dummy data for full duplex devices */
660 int (*fw_translate_cs)(struct spi_controller *ctlr, unsigned cs);
663 * Driver sets this field to indicate it is able to snapshot SPI
664 * transfers (needed e.g. for reading the time of POSIX clocks)
666 bool ptp_sts_supported;
668 /* Interrupt enable state during PTP system timestamping */
669 unsigned long irq_flags;
672 static inline void *spi_controller_get_devdata(struct spi_controller *ctlr)
674 return dev_get_drvdata(&ctlr->dev);
677 static inline void spi_controller_set_devdata(struct spi_controller *ctlr,
680 dev_set_drvdata(&ctlr->dev, data);
683 static inline struct spi_controller *spi_controller_get(struct spi_controller *ctlr)
685 if (!ctlr || !get_device(&ctlr->dev))
690 static inline void spi_controller_put(struct spi_controller *ctlr)
693 put_device(&ctlr->dev);
696 static inline bool spi_controller_is_slave(struct spi_controller *ctlr)
698 return IS_ENABLED(CONFIG_SPI_SLAVE) && ctlr->slave;
701 /* PM calls that need to be issued by the driver */
702 extern int spi_controller_suspend(struct spi_controller *ctlr);
703 extern int spi_controller_resume(struct spi_controller *ctlr);
705 /* Calls the driver make to interact with the message queue */
706 extern struct spi_message *spi_get_next_queued_message(struct spi_controller *ctlr);
707 extern void spi_finalize_current_message(struct spi_controller *ctlr);
708 extern void spi_finalize_current_transfer(struct spi_controller *ctlr);
710 /* Helper calls for driver to timestamp transfer */
711 void spi_take_timestamp_pre(struct spi_controller *ctlr,
712 struct spi_transfer *xfer,
713 size_t progress, bool irqs_off);
714 void spi_take_timestamp_post(struct spi_controller *ctlr,
715 struct spi_transfer *xfer,
716 size_t progress, bool irqs_off);
718 /* the spi driver core manages memory for the spi_controller classdev */
719 extern struct spi_controller *__spi_alloc_controller(struct device *host,
720 unsigned int size, bool slave);
722 static inline struct spi_controller *spi_alloc_master(struct device *host,
725 return __spi_alloc_controller(host, size, false);
728 static inline struct spi_controller *spi_alloc_slave(struct device *host,
731 if (!IS_ENABLED(CONFIG_SPI_SLAVE))
734 return __spi_alloc_controller(host, size, true);
737 struct spi_controller *__devm_spi_alloc_controller(struct device *dev,
741 static inline struct spi_controller *devm_spi_alloc_master(struct device *dev,
744 return __devm_spi_alloc_controller(dev, size, false);
747 static inline struct spi_controller *devm_spi_alloc_slave(struct device *dev,
750 if (!IS_ENABLED(CONFIG_SPI_SLAVE))
753 return __devm_spi_alloc_controller(dev, size, true);
756 extern int spi_register_controller(struct spi_controller *ctlr);
757 extern int devm_spi_register_controller(struct device *dev,
758 struct spi_controller *ctlr);
759 extern void spi_unregister_controller(struct spi_controller *ctlr);
761 #if IS_ENABLED(CONFIG_ACPI)
762 extern struct spi_device *acpi_spi_device_alloc(struct spi_controller *ctlr,
763 struct acpi_device *adev,
765 int acpi_spi_count_resources(struct acpi_device *adev);
769 * SPI resource management while processing a SPI message
772 typedef void (*spi_res_release_t)(struct spi_controller *ctlr,
773 struct spi_message *msg,
777 * struct spi_res - spi resource management structure
779 * @release: release code called prior to freeing this resource
780 * @data: extra data allocated for the specific use-case
782 * this is based on ideas from devres, but focused on life-cycle
783 * management during spi_message processing
786 struct list_head entry;
787 spi_res_release_t release;
788 unsigned long long data[]; /* guarantee ull alignment */
791 /*---------------------------------------------------------------------------*/
794 * I/O INTERFACE between SPI controller and protocol drivers
796 * Protocol drivers use a queue of spi_messages, each transferring data
797 * between the controller and memory buffers.
799 * The spi_messages themselves consist of a series of read+write transfer
800 * segments. Those segments always read the same number of bits as they
801 * write; but one or the other is easily ignored by passing a null buffer
802 * pointer. (This is unlike most types of I/O API, because SPI hardware
805 * NOTE: Allocation of spi_transfer and spi_message memory is entirely
806 * up to the protocol driver, which guarantees the integrity of both (as
807 * well as the data buffers) for as long as the message is queued.
811 * struct spi_transfer - a read/write buffer pair
812 * @tx_buf: data to be written (dma-safe memory), or NULL
813 * @rx_buf: data to be read (dma-safe memory), or NULL
814 * @tx_dma: DMA address of tx_buf, if @spi_message.is_dma_mapped
815 * @rx_dma: DMA address of rx_buf, if @spi_message.is_dma_mapped
816 * @tx_nbits: number of bits used for writing. If 0 the default
817 * (SPI_NBITS_SINGLE) is used.
818 * @rx_nbits: number of bits used for reading. If 0 the default
819 * (SPI_NBITS_SINGLE) is used.
820 * @len: size of rx and tx buffers (in bytes)
821 * @speed_hz: Select a speed other than the device default for this
822 * transfer. If 0 the default (from @spi_device) is used.
823 * @bits_per_word: select a bits_per_word other than the device default
824 * for this transfer. If 0 the default (from @spi_device) is used.
825 * @dummy_data: indicates transfer is dummy bytes transfer.
826 * @cs_change: affects chipselect after this transfer completes
827 * @cs_change_delay: delay between cs deassert and assert when
828 * @cs_change is set and @spi_transfer is not the last in @spi_message
829 * @delay: delay to be introduced after this transfer before
830 * (optionally) changing the chipselect status, then starting
831 * the next transfer or completing this @spi_message.
832 * @word_delay: inter word delay to be introduced after each word size
833 * (set by bits_per_word) transmission.
834 * @effective_speed_hz: the effective SCK-speed that was used to
835 * transfer this transfer. Set to 0 if the spi bus driver does
837 * @transfer_list: transfers are sequenced through @spi_message.transfers
838 * @tx_sg: Scatterlist for transmit, currently not for client use
839 * @rx_sg: Scatterlist for receive, currently not for client use
840 * @ptp_sts_word_pre: The word (subject to bits_per_word semantics) offset
841 * within @tx_buf for which the SPI device is requesting that the time
842 * snapshot for this transfer begins. Upon completing the SPI transfer,
843 * this value may have changed compared to what was requested, depending
844 * on the available snapshotting resolution (DMA transfer,
845 * @ptp_sts_supported is false, etc).
846 * @ptp_sts_word_post: See @ptp_sts_word_post. The two can be equal (meaning
847 * that a single byte should be snapshotted).
848 * If the core takes care of the timestamp (if @ptp_sts_supported is false
849 * for this controller), it will set @ptp_sts_word_pre to 0, and
850 * @ptp_sts_word_post to the length of the transfer. This is done
851 * purposefully (instead of setting to spi_transfer->len - 1) to denote
852 * that a transfer-level snapshot taken from within the driver may still
853 * be of higher quality.
854 * @ptp_sts: Pointer to a memory location held by the SPI slave device where a
855 * PTP system timestamp structure may lie. If drivers use PIO or their
856 * hardware has some sort of assist for retrieving exact transfer timing,
857 * they can (and should) assert @ptp_sts_supported and populate this
858 * structure using the ptp_read_system_*ts helper functions.
859 * The timestamp must represent the time at which the SPI slave device has
860 * processed the word, i.e. the "pre" timestamp should be taken before
861 * transmitting the "pre" word, and the "post" timestamp after receiving
862 * transmit confirmation from the controller for the "post" word.
863 * @timestamped: true if the transfer has been timestamped
864 * @error: Error status logged by spi controller driver.
866 * SPI transfers always write the same number of bytes as they read.
867 * Protocol drivers should always provide @rx_buf and/or @tx_buf.
868 * In some cases, they may also want to provide DMA addresses for
869 * the data being transferred; that may reduce overhead, when the
870 * underlying driver uses dma.
872 * If the transmit buffer is null, zeroes will be shifted out
873 * while filling @rx_buf. If the receive buffer is null, the data
874 * shifted in will be discarded. Only "len" bytes shift out (or in).
875 * It's an error to try to shift out a partial word. (For example, by
876 * shifting out three bytes with word size of sixteen or twenty bits;
877 * the former uses two bytes per word, the latter uses four bytes.)
879 * In-memory data values are always in native CPU byte order, translated
880 * from the wire byte order (big-endian except with SPI_LSB_FIRST). So
881 * for example when bits_per_word is sixteen, buffers are 2N bytes long
882 * (@len = 2N) and hold N sixteen bit words in CPU byte order.
884 * When the word size of the SPI transfer is not a power-of-two multiple
885 * of eight bits, those in-memory words include extra bits. In-memory
886 * words are always seen by protocol drivers as right-justified, so the
887 * undefined (rx) or unused (tx) bits are always the most significant bits.
889 * All SPI transfers start with the relevant chipselect active. Normally
890 * it stays selected until after the last transfer in a message. Drivers
891 * can affect the chipselect signal using cs_change.
893 * (i) If the transfer isn't the last one in the message, this flag is
894 * used to make the chipselect briefly go inactive in the middle of the
895 * message. Toggling chipselect in this way may be needed to terminate
896 * a chip command, letting a single spi_message perform all of group of
897 * chip transactions together.
899 * (ii) When the transfer is the last one in the message, the chip may
900 * stay selected until the next transfer. On multi-device SPI busses
901 * with nothing blocking messages going to other devices, this is just
902 * a performance hint; starting a message to another device deselects
903 * this one. But in other cases, this can be used to ensure correctness.
904 * Some devices need protocol transactions to be built from a series of
905 * spi_message submissions, where the content of one message is determined
906 * by the results of previous messages and where the whole transaction
907 * ends when the chipselect goes intactive.
909 * When SPI can transfer in 1x,2x or 4x. It can get this transfer information
910 * from device through @tx_nbits and @rx_nbits. In Bi-direction, these
911 * two should both be set. User can set transfer mode with SPI_NBITS_SINGLE(1x)
912 * SPI_NBITS_DUAL(2x) and SPI_NBITS_QUAD(4x) to support these three transfer.
914 * The code that submits an spi_message (and its spi_transfers)
915 * to the lower layers is responsible for managing its memory.
916 * Zero-initialize every field you don't set up explicitly, to
917 * insulate against future API updates. After you submit a message
918 * and its transfers, ignore them until its completion callback.
920 struct spi_transfer {
921 /* it's ok if tx_buf == rx_buf (right?)
922 * for MicroWire, one buffer must be null
923 * buffers must work with dma_*map_single() calls, unless
924 * spi_message.is_dma_mapped reports a pre-existing mapping
932 struct sg_table tx_sg;
933 struct sg_table rx_sg;
935 unsigned dummy_data:1;
936 unsigned cs_change:1;
939 #define SPI_NBITS_SINGLE 0x01 /* 1bit transfer */
940 #define SPI_NBITS_DUAL 0x02 /* 2bits transfer */
941 #define SPI_NBITS_QUAD 0x04 /* 4bits transfer */
943 struct spi_delay delay;
944 struct spi_delay cs_change_delay;
945 struct spi_delay word_delay;
948 u32 effective_speed_hz;
950 unsigned int ptp_sts_word_pre;
951 unsigned int ptp_sts_word_post;
953 struct ptp_system_timestamp *ptp_sts;
957 struct list_head transfer_list;
959 #define SPI_TRANS_FAIL_NO_START BIT(0)
964 * struct spi_message - one multi-segment SPI transaction
965 * @transfers: list of transfer segments in this transaction
966 * @spi: SPI device to which the transaction is queued
967 * @is_dma_mapped: if true, the caller provided both dma and cpu virtual
968 * addresses for each transfer buffer
969 * @complete: called to report transaction completions
970 * @context: the argument to complete() when it's called
971 * @frame_length: the total number of bytes in the message
972 * @actual_length: the total number of bytes that were transferred in all
973 * successful segments
974 * @status: zero for success, else negative errno
975 * @queue: for use by whichever driver currently owns the message
976 * @state: for use by whichever driver currently owns the message
977 * @resources: for resource management when the spi message is processed
979 * A @spi_message is used to execute an atomic sequence of data transfers,
980 * each represented by a struct spi_transfer. The sequence is "atomic"
981 * in the sense that no other spi_message may use that SPI bus until that
982 * sequence completes. On some systems, many such sequences can execute as
983 * a single programmed DMA transfer. On all systems, these messages are
984 * queued, and might complete after transactions to other devices. Messages
985 * sent to a given spi_device are always executed in FIFO order.
987 * The code that submits an spi_message (and its spi_transfers)
988 * to the lower layers is responsible for managing its memory.
989 * Zero-initialize every field you don't set up explicitly, to
990 * insulate against future API updates. After you submit a message
991 * and its transfers, ignore them until its completion callback.
994 struct list_head transfers;
996 struct spi_device *spi;
998 unsigned is_dma_mapped:1;
1000 /* REVISIT: we might want a flag affecting the behavior of the
1001 * last transfer ... allowing things like "read 16 bit length L"
1002 * immediately followed by "read L bytes". Basically imposing
1003 * a specific message scheduling algorithm.
1005 * Some controller drivers (message-at-a-time queue processing)
1006 * could provide that as their default scheduling algorithm. But
1007 * others (with multi-message pipelines) could need a flag to
1008 * tell them about such special cases.
1011 /* completion is reported through a callback */
1012 void (*complete)(void *context);
1014 unsigned frame_length;
1015 unsigned actual_length;
1018 /* for optional use by whatever driver currently owns the
1019 * spi_message ... between calls to spi_async and then later
1020 * complete(), that's the spi_controller controller driver.
1022 struct list_head queue;
1025 /* list of spi_res reources when the spi message is processed */
1026 struct list_head resources;
1029 static inline void spi_message_init_no_memset(struct spi_message *m)
1031 INIT_LIST_HEAD(&m->transfers);
1032 INIT_LIST_HEAD(&m->resources);
1035 static inline void spi_message_init(struct spi_message *m)
1037 memset(m, 0, sizeof *m);
1038 spi_message_init_no_memset(m);
1042 spi_message_add_tail(struct spi_transfer *t, struct spi_message *m)
1044 list_add_tail(&t->transfer_list, &m->transfers);
1048 spi_transfer_del(struct spi_transfer *t)
1050 list_del(&t->transfer_list);
1054 spi_transfer_delay_exec(struct spi_transfer *t)
1056 return spi_delay_exec(&t->delay, t);
1060 * spi_message_init_with_transfers - Initialize spi_message and append transfers
1061 * @m: spi_message to be initialized
1062 * @xfers: An array of spi transfers
1063 * @num_xfers: Number of items in the xfer array
1065 * This function initializes the given spi_message and adds each spi_transfer in
1066 * the given array to the message.
1069 spi_message_init_with_transfers(struct spi_message *m,
1070 struct spi_transfer *xfers, unsigned int num_xfers)
1074 spi_message_init(m);
1075 for (i = 0; i < num_xfers; ++i)
1076 spi_message_add_tail(&xfers[i], m);
1079 /* It's fine to embed message and transaction structures in other data
1080 * structures so long as you don't free them while they're in use.
1083 static inline struct spi_message *spi_message_alloc(unsigned ntrans, gfp_t flags)
1085 struct spi_message *m;
1087 m = kzalloc(sizeof(struct spi_message)
1088 + ntrans * sizeof(struct spi_transfer),
1092 struct spi_transfer *t = (struct spi_transfer *)(m + 1);
1094 spi_message_init_no_memset(m);
1095 for (i = 0; i < ntrans; i++, t++)
1096 spi_message_add_tail(t, m);
1101 static inline void spi_message_free(struct spi_message *m)
1106 extern int spi_setup(struct spi_device *spi);
1107 extern int spi_async(struct spi_device *spi, struct spi_message *message);
1108 extern int spi_slave_abort(struct spi_device *spi);
1110 static inline size_t
1111 spi_max_message_size(struct spi_device *spi)
1113 struct spi_controller *ctlr = spi->controller;
1115 if (!ctlr->max_message_size)
1117 return ctlr->max_message_size(spi);
1120 static inline size_t
1121 spi_max_transfer_size(struct spi_device *spi)
1123 struct spi_controller *ctlr = spi->controller;
1124 size_t tr_max = SIZE_MAX;
1125 size_t msg_max = spi_max_message_size(spi);
1127 if (ctlr->max_transfer_size)
1128 tr_max = ctlr->max_transfer_size(spi);
1130 /* transfer size limit must not be greater than messsage size limit */
1131 return min(tr_max, msg_max);
1135 * spi_is_bpw_supported - Check if bits per word is supported
1137 * @bpw: Bits per word
1139 * This function checks to see if the SPI controller supports @bpw.
1142 * True if @bpw is supported, false otherwise.
1144 static inline bool spi_is_bpw_supported(struct spi_device *spi, u32 bpw)
1146 u32 bpw_mask = spi->master->bits_per_word_mask;
1148 if (bpw == 8 || (bpw <= 32 && bpw_mask & SPI_BPW_MASK(bpw)))
1154 /*---------------------------------------------------------------------------*/
1156 /* SPI transfer replacement methods which make use of spi_res */
1158 struct spi_replaced_transfers;
1159 typedef void (*spi_replaced_release_t)(struct spi_controller *ctlr,
1160 struct spi_message *msg,
1161 struct spi_replaced_transfers *res);
1163 * struct spi_replaced_transfers - structure describing the spi_transfer
1164 * replacements that have occurred
1165 * so that they can get reverted
1166 * @release: some extra release code to get executed prior to
1167 * relasing this structure
1168 * @extradata: pointer to some extra data if requested or NULL
1169 * @replaced_transfers: transfers that have been replaced and which need
1171 * @replaced_after: the transfer after which the @replaced_transfers
1172 * are to get re-inserted
1173 * @inserted: number of transfers inserted
1174 * @inserted_transfers: array of spi_transfers of array-size @inserted,
1175 * that have been replacing replaced_transfers
1177 * note: that @extradata will point to @inserted_transfers[@inserted]
1178 * if some extra allocation is requested, so alignment will be the same
1179 * as for spi_transfers
1181 struct spi_replaced_transfers {
1182 spi_replaced_release_t release;
1184 struct list_head replaced_transfers;
1185 struct list_head *replaced_after;
1187 struct spi_transfer inserted_transfers[];
1190 /*---------------------------------------------------------------------------*/
1192 /* SPI transfer transformation methods */
1194 extern int spi_split_transfers_maxsize(struct spi_controller *ctlr,
1195 struct spi_message *msg,
1199 /*---------------------------------------------------------------------------*/
1201 /* All these synchronous SPI transfer routines are utilities layered
1202 * over the core async transfer primitive. Here, "synchronous" means
1203 * they will sleep uninterruptibly until the async transfer completes.
1206 extern int spi_sync(struct spi_device *spi, struct spi_message *message);
1207 extern int spi_sync_locked(struct spi_device *spi, struct spi_message *message);
1208 extern int spi_bus_lock(struct spi_controller *ctlr);
1209 extern int spi_bus_unlock(struct spi_controller *ctlr);
1212 * spi_sync_transfer - synchronous SPI data transfer
1213 * @spi: device with which data will be exchanged
1214 * @xfers: An array of spi_transfers
1215 * @num_xfers: Number of items in the xfer array
1216 * Context: can sleep
1218 * Does a synchronous SPI data transfer of the given spi_transfer array.
1220 * For more specific semantics see spi_sync().
1222 * Return: zero on success, else a negative error code.
1225 spi_sync_transfer(struct spi_device *spi, struct spi_transfer *xfers,
1226 unsigned int num_xfers)
1228 struct spi_message msg;
1230 spi_message_init_with_transfers(&msg, xfers, num_xfers);
1232 return spi_sync(spi, &msg);
1236 * spi_write - SPI synchronous write
1237 * @spi: device to which data will be written
1239 * @len: data buffer size
1240 * Context: can sleep
1242 * This function writes the buffer @buf.
1243 * Callable only from contexts that can sleep.
1245 * Return: zero on success, else a negative error code.
1248 spi_write(struct spi_device *spi, const void *buf, size_t len)
1250 struct spi_transfer t = {
1255 return spi_sync_transfer(spi, &t, 1);
1259 * spi_read - SPI synchronous read
1260 * @spi: device from which data will be read
1262 * @len: data buffer size
1263 * Context: can sleep
1265 * This function reads the buffer @buf.
1266 * Callable only from contexts that can sleep.
1268 * Return: zero on success, else a negative error code.
1271 spi_read(struct spi_device *spi, void *buf, size_t len)
1273 struct spi_transfer t = {
1278 return spi_sync_transfer(spi, &t, 1);
1281 /* this copies txbuf and rxbuf data; for small transfers only! */
1282 extern int spi_write_then_read(struct spi_device *spi,
1283 const void *txbuf, unsigned n_tx,
1284 void *rxbuf, unsigned n_rx);
1287 * spi_w8r8 - SPI synchronous 8 bit write followed by 8 bit read
1288 * @spi: device with which data will be exchanged
1289 * @cmd: command to be written before data is read back
1290 * Context: can sleep
1292 * Callable only from contexts that can sleep.
1294 * Return: the (unsigned) eight bit number returned by the
1295 * device, or else a negative error code.
1297 static inline ssize_t spi_w8r8(struct spi_device *spi, u8 cmd)
1302 status = spi_write_then_read(spi, &cmd, 1, &result, 1);
1304 /* return negative errno or unsigned value */
1305 return (status < 0) ? status : result;
1309 * spi_w8r16 - SPI synchronous 8 bit write followed by 16 bit read
1310 * @spi: device with which data will be exchanged
1311 * @cmd: command to be written before data is read back
1312 * Context: can sleep
1314 * The number is returned in wire-order, which is at least sometimes
1317 * Callable only from contexts that can sleep.
1319 * Return: the (unsigned) sixteen bit number returned by the
1320 * device, or else a negative error code.
1322 static inline ssize_t spi_w8r16(struct spi_device *spi, u8 cmd)
1327 status = spi_write_then_read(spi, &cmd, 1, &result, 2);
1329 /* return negative errno or unsigned value */
1330 return (status < 0) ? status : result;
1334 * spi_w8r16be - SPI synchronous 8 bit write followed by 16 bit big-endian read
1335 * @spi: device with which data will be exchanged
1336 * @cmd: command to be written before data is read back
1337 * Context: can sleep
1339 * This function is similar to spi_w8r16, with the exception that it will
1340 * convert the read 16 bit data word from big-endian to native endianness.
1342 * Callable only from contexts that can sleep.
1344 * Return: the (unsigned) sixteen bit number returned by the device in cpu
1345 * endianness, or else a negative error code.
1347 static inline ssize_t spi_w8r16be(struct spi_device *spi, u8 cmd)
1353 status = spi_write_then_read(spi, &cmd, 1, &result, 2);
1357 return be16_to_cpu(result);
1360 /*---------------------------------------------------------------------------*/
1363 * INTERFACE between board init code and SPI infrastructure.
1365 * No SPI driver ever sees these SPI device table segments, but
1366 * it's how the SPI core (or adapters that get hotplugged) grows
1367 * the driver model tree.
1369 * As a rule, SPI devices can't be probed. Instead, board init code
1370 * provides a table listing the devices which are present, with enough
1371 * information to bind and set up the device's driver. There's basic
1372 * support for nonstatic configurations too; enough to handle adding
1373 * parport adapters, or microcontrollers acting as USB-to-SPI bridges.
1377 * struct spi_board_info - board-specific template for a SPI device
1378 * @modalias: Initializes spi_device.modalias; identifies the driver.
1379 * @platform_data: Initializes spi_device.platform_data; the particular
1380 * data stored there is driver-specific.
1381 * @swnode: Software node for the device.
1382 * @controller_data: Initializes spi_device.controller_data; some
1383 * controllers need hints about hardware setup, e.g. for DMA.
1384 * @irq: Initializes spi_device.irq; depends on how the board is wired.
1385 * @max_speed_hz: Initializes spi_device.max_speed_hz; based on limits
1386 * from the chip datasheet and board-specific signal quality issues.
1387 * @bus_num: Identifies which spi_controller parents the spi_device; unused
1388 * by spi_new_device(), and otherwise depends on board wiring.
1389 * @chip_select: Initializes spi_device.chip_select; depends on how
1390 * the board is wired.
1391 * @mode: Initializes spi_device.mode; based on the chip datasheet, board
1392 * wiring (some devices support both 3WIRE and standard modes), and
1393 * possibly presence of an inverter in the chipselect path.
1395 * When adding new SPI devices to the device tree, these structures serve
1396 * as a partial device template. They hold information which can't always
1397 * be determined by drivers. Information that probe() can establish (such
1398 * as the default transfer wordsize) is not included here.
1400 * These structures are used in two places. Their primary role is to
1401 * be stored in tables of board-specific device descriptors, which are
1402 * declared early in board initialization and then used (much later) to
1403 * populate a controller's device tree after the that controller's driver
1404 * initializes. A secondary (and atypical) role is as a parameter to
1405 * spi_new_device() call, which happens after those controller drivers
1406 * are active in some dynamic board configuration models.
1408 struct spi_board_info {
1409 /* the device name and module name are coupled, like platform_bus;
1410 * "modalias" is normally the driver name.
1412 * platform_data goes to spi_device.dev.platform_data,
1413 * controller_data goes to spi_device.controller_data,
1416 char modalias[SPI_NAME_SIZE];
1417 const void *platform_data;
1418 const struct software_node *swnode;
1419 void *controller_data;
1422 /* slower signaling on noisy or low voltage boards */
1426 /* bus_num is board specific and matches the bus_num of some
1427 * spi_controller that will probably be registered later.
1429 * chip_select reflects how this chip is wired to that master;
1430 * it's less than num_chipselect.
1435 /* mode becomes spi_device.mode, and is essential for chips
1436 * where the default of SPI_CS_HIGH = 0 is wrong.
1440 /* ... may need additional spi_device chip config data here.
1441 * avoid stuff protocol drivers can set; but include stuff
1442 * needed to behave without being bound to a driver:
1443 * - quirks like clock rate mattering when not selected
1449 spi_register_board_info(struct spi_board_info const *info, unsigned n);
1451 /* board init code may ignore whether SPI is configured or not */
1453 spi_register_board_info(struct spi_board_info const *info, unsigned n)
1457 /* If you're hotplugging an adapter with devices (parport, usb, etc)
1458 * use spi_new_device() to describe each device. You can also call
1459 * spi_unregister_device() to start making that device vanish, but
1460 * normally that would be handled by spi_unregister_controller().
1462 * You can also use spi_alloc_device() and spi_add_device() to use a two
1463 * stage registration sequence for each spi_device. This gives the caller
1464 * some more control over the spi_device structure before it is registered,
1465 * but requires that caller to initialize fields that would otherwise
1466 * be defined using the board info.
1468 extern struct spi_device *
1469 spi_alloc_device(struct spi_controller *ctlr);
1472 spi_add_device(struct spi_device *spi);
1474 extern struct spi_device *
1475 spi_new_device(struct spi_controller *, struct spi_board_info *);
1477 extern void spi_unregister_device(struct spi_device *spi);
1479 extern const struct spi_device_id *
1480 spi_get_device_id(const struct spi_device *sdev);
1483 spi_transfer_is_last(struct spi_controller *ctlr, struct spi_transfer *xfer)
1485 return list_is_last(&xfer->transfer_list, &ctlr->cur_msg->transfers);
1488 /* Compatibility layer */
1489 #define spi_master spi_controller
1491 #define SPI_MASTER_HALF_DUPLEX SPI_CONTROLLER_HALF_DUPLEX
1492 #define SPI_MASTER_NO_RX SPI_CONTROLLER_NO_RX
1493 #define SPI_MASTER_NO_TX SPI_CONTROLLER_NO_TX
1494 #define SPI_MASTER_MUST_RX SPI_CONTROLLER_MUST_RX
1495 #define SPI_MASTER_MUST_TX SPI_CONTROLLER_MUST_TX
1497 #define spi_master_get_devdata(_ctlr) spi_controller_get_devdata(_ctlr)
1498 #define spi_master_set_devdata(_ctlr, _data) \
1499 spi_controller_set_devdata(_ctlr, _data)
1500 #define spi_master_get(_ctlr) spi_controller_get(_ctlr)
1501 #define spi_master_put(_ctlr) spi_controller_put(_ctlr)
1502 #define spi_master_suspend(_ctlr) spi_controller_suspend(_ctlr)
1503 #define spi_master_resume(_ctlr) spi_controller_resume(_ctlr)
1505 #define spi_register_master(_ctlr) spi_register_controller(_ctlr)
1506 #define devm_spi_register_master(_dev, _ctlr) \
1507 devm_spi_register_controller(_dev, _ctlr)
1508 #define spi_unregister_master(_ctlr) spi_unregister_controller(_ctlr)
1510 #endif /* __LINUX_SPI_H */