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Marco Felschb445bfc2018-09-25 11:42:28 +02001/* SPDX-License-Identifier: GPL-2.0-or-later
2 *
David Brownell8ae12a02006-01-08 13:34:19 -08003 * Copyright (C) 2005 David Brownell
David Brownell8ae12a02006-01-08 13:34:19 -08004 */
5
6#ifndef __LINUX_SPI_H
7#define __LINUX_SPI_H
8
Randy Dunlap0a30c5c2009-01-04 12:00:47 -08009#include <linux/device.h>
Anton Vorontsov75368bf2009-09-22 16:46:04 -070010#include <linux/mod_devicetable.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090011#include <linux/slab.h>
Linus Walleijffbbdd212012-02-22 10:05:38 +010012#include <linux/kthread.h>
Mark Brownb1589352013-10-05 11:50:40 +010013#include <linux/completion.h>
Mark Brown6ad45a22014-02-02 13:47:47 +000014#include <linux/scatterlist.h>
Linus Walleijf3186dd2019-01-07 16:51:50 +010015#include <linux/gpio/consumer.h>
Randy Dunlap0a30c5c2009-01-04 12:00:47 -080016
Mark Brown99adef32014-01-16 12:22:43 +000017struct dma_chan;
Dmitry Torokhov826cf172017-02-28 14:25:18 -080018struct property_entry;
Geert Uytterhoeven8caab752017-06-13 13:23:52 +020019struct spi_controller;
Martin Sperleca2ebc2015-06-22 13:00:36 +000020struct spi_transfer;
Boris Brezillonc36ff262018-04-26 18:18:14 +020021struct spi_controller_mem_ops;
David Brownellb8852442006-01-08 13:34:23 -080022
David Brownell8ae12a02006-01-08 13:34:19 -080023/*
Geert Uytterhoeven6c364062017-05-22 15:11:41 +020024 * INTERFACES between SPI master-side drivers and SPI slave protocol handlers,
25 * and SPI infrastructure.
David Brownell8ae12a02006-01-08 13:34:19 -080026 */
27extern struct bus_type spi_bus_type;
28
29/**
Martin Sperleca2ebc2015-06-22 13:00:36 +000030 * struct spi_statistics - statistics for spi transfers
Geliang Tang0243ed42015-09-15 04:59:21 -070031 * @lock: lock protecting this structure
Martin Sperleca2ebc2015-06-22 13:00:36 +000032 *
33 * @messages: number of spi-messages handled
34 * @transfers: number of spi_transfers handled
35 * @errors: number of errors during spi_transfer
36 * @timedout: number of timeouts during spi_transfer
37 *
38 * @spi_sync: number of times spi_sync is used
39 * @spi_sync_immediate:
40 * number of times spi_sync is executed immediately
41 * in calling context without queuing and scheduling
42 * @spi_async: number of times spi_async is used
43 *
44 * @bytes: number of bytes transferred to/from device
45 * @bytes_tx: number of bytes sent to device
46 * @bytes_rx: number of bytes received from device
47 *
Martin Sperl6b7bc062015-06-22 13:02:04 +000048 * @transfer_bytes_histo:
49 * transfer bytes histogramm
Martin Sperld9f12122015-12-14 15:20:20 +000050 *
51 * @transfers_split_maxsize:
52 * number of transfers that have been split because of
53 * maxsize limit
Martin Sperleca2ebc2015-06-22 13:00:36 +000054 */
55struct spi_statistics {
56 spinlock_t lock; /* lock for the whole structure */
57
58 unsigned long messages;
59 unsigned long transfers;
60 unsigned long errors;
61 unsigned long timedout;
62
63 unsigned long spi_sync;
64 unsigned long spi_sync_immediate;
65 unsigned long spi_async;
66
67 unsigned long long bytes;
68 unsigned long long bytes_rx;
69 unsigned long long bytes_tx;
70
Martin Sperl6b7bc062015-06-22 13:02:04 +000071#define SPI_STATISTICS_HISTO_SIZE 17
72 unsigned long transfer_bytes_histo[SPI_STATISTICS_HISTO_SIZE];
Martin Sperld9f12122015-12-14 15:20:20 +000073
74 unsigned long transfers_split_maxsize;
Martin Sperleca2ebc2015-06-22 13:00:36 +000075};
76
77void spi_statistics_add_transfer_stats(struct spi_statistics *stats,
78 struct spi_transfer *xfer,
Geert Uytterhoeven8caab752017-06-13 13:23:52 +020079 struct spi_controller *ctlr);
Martin Sperleca2ebc2015-06-22 13:00:36 +000080
81#define SPI_STATISTICS_ADD_TO_FIELD(stats, field, count) \
82 do { \
83 unsigned long flags; \
84 spin_lock_irqsave(&(stats)->lock, flags); \
85 (stats)->field += count; \
86 spin_unlock_irqrestore(&(stats)->lock, flags); \
87 } while (0)
88
89#define SPI_STATISTICS_INCREMENT_FIELD(stats, field) \
90 SPI_STATISTICS_ADD_TO_FIELD(stats, field, 1)
91
92/**
Geert Uytterhoeven8caab752017-06-13 13:23:52 +020093 * struct spi_device - Controller side proxy for an SPI slave device
David Brownell8ae12a02006-01-08 13:34:19 -080094 * @dev: Driver model representation of the device.
Geert Uytterhoeven8caab752017-06-13 13:23:52 +020095 * @controller: SPI controller used with the device.
96 * @master: Copy of controller, for backwards compatibility.
David Brownell8ae12a02006-01-08 13:34:19 -080097 * @max_speed_hz: Maximum clock rate to be used with this chip
98 * (on this board); may be changed by the device's driver.
Imre Deak4cff33f2006-02-17 10:02:18 -080099 * The spi_transfer.speed_hz can override this for each transfer.
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200100 * @chip_select: Chipselect, distinguishing chips handled by @controller.
David Brownell8ae12a02006-01-08 13:34:19 -0800101 * @mode: The spi mode defines how data is clocked out and in.
102 * This may be changed by the device's driver.
David Brownell33e34dc2007-05-08 00:32:21 -0700103 * The "active low" default for chipselect mode can be overridden
104 * (by specifying SPI_CS_HIGH) as can the "MSB first" default for
105 * each word in a transfer (by specifying SPI_LSB_FIRST).
David Brownell8ae12a02006-01-08 13:34:19 -0800106 * @bits_per_word: Data transfers involve one or more words; word sizes
David Brownell747d8442006-04-02 10:33:37 -0800107 * like eight or 12 bits are common. In-memory wordsizes are
David Brownell8ae12a02006-01-08 13:34:19 -0800108 * powers of two bytes (e.g. 20 bit samples use 32 bits).
David Brownellccf77cc2006-04-03 15:46:22 -0700109 * This may be changed by the device's driver, or left at the
110 * default (0) indicating protocol words are eight bit bytes.
Imre Deak4cff33f2006-02-17 10:02:18 -0800111 * The spi_transfer.bits_per_word can override this for each transfer.
David Brownell8ae12a02006-01-08 13:34:19 -0800112 * @irq: Negative, or the number passed to request_irq() to receive
David Brownell747d8442006-04-02 10:33:37 -0800113 * interrupts from this device.
David Brownell8ae12a02006-01-08 13:34:19 -0800114 * @controller_state: Controller's runtime state
David Brownellb8852442006-01-08 13:34:23 -0800115 * @controller_data: Board-specific definitions for controller, such as
David Brownell747d8442006-04-02 10:33:37 -0800116 * FIFO initialization parameters; from board_info.controller_data
David Brownell33e34dc2007-05-08 00:32:21 -0700117 * @modalias: Name of the driver to use with this device, or an alias
118 * for that name. This appears in the sysfs "modalias" attribute
119 * for driver coldplugging, and in uevents used for hotplugging
Linus Walleijf3186dd2019-01-07 16:51:50 +0100120 * @cs_gpio: LEGACY: gpio number of the chipselect line (optional, -ENOENT when
121 * not using a GPIO line) use cs_gpiod in new drivers by opting in on
122 * the spi_master.
123 * @cs_gpiod: gpio descriptor of the chipselect line (optional, NULL when
Geert Uytterhoeven8d26fdf2017-11-30 14:35:08 +0100124 * not using a GPIO line)
David Brownell8ae12a02006-01-08 13:34:19 -0800125 *
Martin Sperleca2ebc2015-06-22 13:00:36 +0000126 * @statistics: statistics for the spi_device
127 *
David Brownell33e34dc2007-05-08 00:32:21 -0700128 * A @spi_device is used to interchange data between an SPI slave
David Brownell8ae12a02006-01-08 13:34:19 -0800129 * (usually a discrete chip) and CPU memory.
130 *
David Brownell33e34dc2007-05-08 00:32:21 -0700131 * In @dev, the platform_data is used to hold information about this
David Brownell8ae12a02006-01-08 13:34:19 -0800132 * device that's meaningful to the device's protocol driver, but not
133 * to its controller. One example might be an identifier for a chip
David Brownell33e34dc2007-05-08 00:32:21 -0700134 * variant with slightly different functionality; another might be
135 * information about how this particular board wires the chip's pins.
David Brownell8ae12a02006-01-08 13:34:19 -0800136 */
137struct spi_device {
138 struct device dev;
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200139 struct spi_controller *controller;
140 struct spi_controller *master; /* compatibility layer */
David Brownell8ae12a02006-01-08 13:34:19 -0800141 u32 max_speed_hz;
142 u8 chip_select;
Trent Piepho89c1f60742013-12-13 18:27:44 -0800143 u8 bits_per_word;
wangyuhangf477b7f2013-08-11 18:15:17 +0800144 u16 mode;
David Brownellb8852442006-01-08 13:34:23 -0800145#define SPI_CPHA 0x01 /* clock phase */
146#define SPI_CPOL 0x02 /* clock polarity */
David Brownell0c8684612006-01-08 13:34:25 -0800147#define SPI_MODE_0 (0|0) /* (original MicroWire) */
148#define SPI_MODE_1 (0|SPI_CPHA)
David Brownell8ae12a02006-01-08 13:34:19 -0800149#define SPI_MODE_2 (SPI_CPOL|0)
150#define SPI_MODE_3 (SPI_CPOL|SPI_CPHA)
David Brownellb8852442006-01-08 13:34:23 -0800151#define SPI_CS_HIGH 0x04 /* chipselect active high? */
David Brownellccf77cc2006-04-03 15:46:22 -0700152#define SPI_LSB_FIRST 0x08 /* per-word bits-on-wire */
David Brownellc06e6772007-07-17 04:04:03 -0700153#define SPI_3WIRE 0x10 /* SI/SO signals shared */
Anton Vorontsov4ef7af52007-07-31 00:38:43 -0700154#define SPI_LOOP 0x20 /* loopback mode */
David Brownellb55f6272009-06-30 11:41:26 -0700155#define SPI_NO_CS 0x40 /* 1 dev/bus, no chipselect */
156#define SPI_READY 0x80 /* slave pulls low to pause */
wangyuhangf477b7f2013-08-11 18:15:17 +0800157#define SPI_TX_DUAL 0x100 /* transmit with 2 wires */
158#define SPI_TX_QUAD 0x200 /* transmit with 4 wires */
159#define SPI_RX_DUAL 0x400 /* receive with 2 wires */
160#define SPI_RX_QUAD 0x800 /* receive with 4 wires */
Yogesh Narayan Gaur6b030612018-12-03 08:39:06 +0000161#define SPI_CS_WORD 0x1000 /* toggle cs after each word */
162#define SPI_TX_OCTAL 0x2000 /* transmit with 8 wires */
163#define SPI_RX_OCTAL 0x4000 /* receive with 8 wires */
Mark Brownae218f72018-12-04 17:31:49 +0000164#define SPI_3WIRE_HIZ 0x8000 /* high impedance turnaround */
David Brownell8ae12a02006-01-08 13:34:19 -0800165 int irq;
166 void *controller_state;
David Brownellb8852442006-01-08 13:34:23 -0800167 void *controller_data;
Anton Vorontsov75368bf2009-09-22 16:46:04 -0700168 char modalias[SPI_NAME_SIZE];
Trent Piepho50395632018-09-20 19:18:32 +0000169 const char *driver_override;
Linus Walleijf3186dd2019-01-07 16:51:50 +0100170 int cs_gpio; /* LEGACY: chip select gpio */
171 struct gpio_desc *cs_gpiod; /* chip select gpio desc */
David Brownell8ae12a02006-01-08 13:34:19 -0800172
Martin Sperleca2ebc2015-06-22 13:00:36 +0000173 /* the statistics */
174 struct spi_statistics statistics;
175
David Brownell33e34dc2007-05-08 00:32:21 -0700176 /*
177 * likely need more hooks for more protocol options affecting how
178 * the controller talks to each chip, like:
179 * - memory packing (12 bit samples into low bits, others zeroed)
180 * - priority
David Brownell33e34dc2007-05-08 00:32:21 -0700181 * - chipselect delays
182 * - ...
183 */
David Brownell8ae12a02006-01-08 13:34:19 -0800184};
185
186static inline struct spi_device *to_spi_device(struct device *dev)
187{
David Brownellb8852442006-01-08 13:34:23 -0800188 return dev ? container_of(dev, struct spi_device, dev) : NULL;
David Brownell8ae12a02006-01-08 13:34:19 -0800189}
190
191/* most drivers won't need to care about device refcounting */
192static inline struct spi_device *spi_dev_get(struct spi_device *spi)
193{
194 return (spi && get_device(&spi->dev)) ? spi : NULL;
195}
196
197static inline void spi_dev_put(struct spi_device *spi)
198{
199 if (spi)
200 put_device(&spi->dev);
201}
202
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200203/* ctldata is for the bus_controller driver's runtime state */
David Brownell8ae12a02006-01-08 13:34:19 -0800204static inline void *spi_get_ctldata(struct spi_device *spi)
205{
206 return spi->controller_state;
207}
208
209static inline void spi_set_ctldata(struct spi_device *spi, void *state)
210{
211 spi->controller_state = state;
212}
213
Ben Dooks9b40ff42007-02-12 00:52:41 -0800214/* device driver data */
215
216static inline void spi_set_drvdata(struct spi_device *spi, void *data)
217{
218 dev_set_drvdata(&spi->dev, data);
219}
220
221static inline void *spi_get_drvdata(struct spi_device *spi)
222{
223 return dev_get_drvdata(&spi->dev);
224}
David Brownell8ae12a02006-01-08 13:34:19 -0800225
226struct spi_message;
Mark Brownb1589352013-10-05 11:50:40 +0100227struct spi_transfer;
David Brownellb8852442006-01-08 13:34:23 -0800228
David Brownell2604288f2007-07-31 00:39:44 -0700229/**
230 * struct spi_driver - Host side "protocol" driver
Anton Vorontsov75368bf2009-09-22 16:46:04 -0700231 * @id_table: List of SPI devices supported by this driver
David Brownell2604288f2007-07-31 00:39:44 -0700232 * @probe: Binds this driver to the spi device. Drivers can verify
233 * that the device is actually present, and may need to configure
234 * characteristics (such as bits_per_word) which weren't needed for
235 * the initial configuration done during system setup.
236 * @remove: Unbinds this driver from the spi device
237 * @shutdown: Standard shutdown callback used during system state
238 * transitions such as powerdown/halt and kexec
David Brownell2604288f2007-07-31 00:39:44 -0700239 * @driver: SPI device drivers should initialize the name and owner
240 * field of this structure.
241 *
242 * This represents the kind of device driver that uses SPI messages to
243 * interact with the hardware at the other end of a SPI link. It's called
244 * a "protocol" driver because it works through messages rather than talking
245 * directly to SPI hardware (which is what the underlying SPI controller
246 * driver does to pass those messages). These protocols are defined in the
247 * specification for the device(s) supported by the driver.
248 *
249 * As a rule, those device protocols represent the lowest level interface
250 * supported by a driver, and it will support upper level interfaces too.
251 * Examples of such upper levels include frameworks like MTD, networking,
252 * MMC, RTC, filesystem character device nodes, and hardware monitoring.
253 */
David Brownellb8852442006-01-08 13:34:23 -0800254struct spi_driver {
Anton Vorontsov75368bf2009-09-22 16:46:04 -0700255 const struct spi_device_id *id_table;
David Brownellb8852442006-01-08 13:34:23 -0800256 int (*probe)(struct spi_device *spi);
257 int (*remove)(struct spi_device *spi);
258 void (*shutdown)(struct spi_device *spi);
David Brownellb8852442006-01-08 13:34:23 -0800259 struct device_driver driver;
260};
261
262static inline struct spi_driver *to_spi_driver(struct device_driver *drv)
263{
264 return drv ? container_of(drv, struct spi_driver, driver) : NULL;
265}
266
Andrew F. Davisca5d2482015-10-23 08:59:10 -0500267extern int __spi_register_driver(struct module *owner, struct spi_driver *sdrv);
David Brownellb8852442006-01-08 13:34:23 -0800268
David Brownell33e34dc2007-05-08 00:32:21 -0700269/**
270 * spi_unregister_driver - reverse effect of spi_register_driver
271 * @sdrv: the driver to unregister
272 * Context: can sleep
273 */
David Brownellb8852442006-01-08 13:34:23 -0800274static inline void spi_unregister_driver(struct spi_driver *sdrv)
275{
Ben Dooksddc1e972007-02-12 00:52:43 -0800276 if (sdrv)
277 driver_unregister(&sdrv->driver);
David Brownellb8852442006-01-08 13:34:23 -0800278}
279
Andrew F. Davisca5d2482015-10-23 08:59:10 -0500280/* use a define to avoid include chaining to get THIS_MODULE */
281#define spi_register_driver(driver) \
282 __spi_register_driver(THIS_MODULE, driver)
283
Lars-Peter Clausen3acbb012011-11-16 10:13:37 +0100284/**
285 * module_spi_driver() - Helper macro for registering a SPI driver
286 * @__spi_driver: spi_driver struct
287 *
288 * Helper macro for SPI drivers which do not do anything special in module
289 * init/exit. This eliminates a lot of boilerplate. Each module may only
290 * use this macro once, and calling it replaces module_init() and module_exit()
291 */
292#define module_spi_driver(__spi_driver) \
293 module_driver(__spi_driver, spi_register_driver, \
294 spi_unregister_driver)
David Brownellb8852442006-01-08 13:34:23 -0800295
David Brownell8ae12a02006-01-08 13:34:19 -0800296/**
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200297 * struct spi_controller - interface to SPI master or slave controller
Tony Jones49dce682007-10-16 01:27:48 -0700298 * @dev: device interface to this driver
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200299 * @list: link with the global spi_controller list
David Brownell8ae12a02006-01-08 13:34:19 -0800300 * @bus_num: board-specific (and often SOC-specific) identifier for a
David Brownell747d8442006-04-02 10:33:37 -0800301 * given SPI controller.
David Brownellb8852442006-01-08 13:34:23 -0800302 * @num_chipselect: chipselects are used to distinguish individual
David Brownell747d8442006-04-02 10:33:37 -0800303 * SPI slaves, and are numbered from zero to num_chipselects.
304 * each slave has a chipselect signal, but it's common that not
305 * every chipselect is connected to a slave.
Mike Rapoportfd5e1912009-04-06 19:00:56 -0700306 * @dma_alignment: SPI controller constraint on DMA buffers alignment.
Randy Dunlapb73b2552009-09-22 16:46:00 -0700307 * @mode_bits: flags understood by this controller driver
Stephen Warren543bb252013-03-26 20:37:57 -0600308 * @bits_per_word_mask: A mask indicating which values of bits_per_word are
309 * supported by the driver. Bit n indicates that a bits_per_word n+1 is
Masanari Iidae2278672014-02-18 22:54:36 +0900310 * supported. If set, the SPI core will reject any transfer with an
Stephen Warren543bb252013-03-26 20:37:57 -0600311 * unsupported bits_per_word. If not set, this value is simply ignored,
312 * and it's up to the individual driver to perform any validation.
Mark Browna2fd4f92013-07-10 14:57:26 +0100313 * @min_speed_hz: Lowest supported transfer speed
314 * @max_speed_hz: Highest supported transfer speed
Randy Dunlapb73b2552009-09-22 16:46:00 -0700315 * @flags: other constraints relevant to this driver
Geert Uytterhoeven6c364062017-05-22 15:11:41 +0200316 * @slave: indicates that this is an SPI slave controller
Randy Dunlapee7683a2016-02-05 17:31:39 -0800317 * @max_transfer_size: function that returns the max transfer size for
318 * a &spi_device; may be %NULL, so the default %SIZE_MAX will be used.
Heiner Kallweit5090cc6a2016-08-17 21:08:01 +0200319 * @max_message_size: function that returns the max message size for
320 * a &spi_device; may be %NULL, so the default %SIZE_MAX will be used.
Mark Brownef4d96e2016-07-21 23:53:31 +0100321 * @io_mutex: mutex for physical bus access
Ernst Schwab5c79a5a2010-08-16 15:10:11 +0200322 * @bus_lock_spinlock: spinlock for SPI bus locking
Mark Brownef4d96e2016-07-21 23:53:31 +0100323 * @bus_lock_mutex: mutex for exclusion of multiple callers
Ernst Schwab5c79a5a2010-08-16 15:10:11 +0200324 * @bus_lock_flag: indicates that the SPI bus is locked for exclusive use
David Brownell8ae12a02006-01-08 13:34:19 -0800325 * @setup: updates the device mode and clocking records used by a
David Brownell80224562007-02-12 00:52:46 -0800326 * device's SPI controller; protocol code may call this. This
327 * must fail if an unrecognized or unsupported mode is requested.
David Brownell33e34dc2007-05-08 00:32:21 -0700328 * It's always safe to call this unless transfers are pending on
329 * the device whose settings are being modified.
David Brownell8ae12a02006-01-08 13:34:19 -0800330 * @transfer: adds a message to the controller's transfer queue.
331 * @cleanup: frees controller-specific state
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200332 * @can_dma: determine whether this controller supports DMA
333 * @queued: whether this controller is providing an internal message queue
Linus Walleijffbbdd212012-02-22 10:05:38 +0100334 * @kworker: thread struct for message pump
335 * @kworker_task: pointer to task for message pump kworker thread
336 * @pump_messages: work struct for scheduling work to the message pump
337 * @queue_lock: spinlock to syncronise access to message queue
338 * @queue: message queue
Mark Brown0461a412014-12-09 21:38:05 +0000339 * @idling: the device is entering idle state
Linus Walleijffbbdd212012-02-22 10:05:38 +0100340 * @cur_msg: the currently in-flight message
Mark Brown2841a5f2013-10-05 00:23:12 +0100341 * @cur_msg_prepared: spi_prepare_message was called for the currently
342 * in-flight message
Thierry Reding2c675682014-08-08 13:02:36 +0200343 * @cur_msg_mapped: message has been mapped for DMA
Masanari Iidae2278672014-02-18 22:54:36 +0900344 * @xfer_completion: used by core transfer_one_message()
Linus Walleijffbbdd212012-02-22 10:05:38 +0100345 * @busy: message pump is busy
346 * @running: message pump is running
347 * @rt: whether this queue is set to run as a realtime task
Mark Brown49834de2013-07-28 14:47:02 +0100348 * @auto_runtime_pm: the core should ensure a runtime PM reference is held
349 * while the hardware is prepared, using the parent
350 * device for the spidev
Mark Brown6ad45a22014-02-02 13:47:47 +0000351 * @max_dma_len: Maximum length of a DMA transfer for the device.
Linus Walleijffbbdd212012-02-22 10:05:38 +0100352 * @prepare_transfer_hardware: a message will soon arrive from the queue
353 * so the subsystem requests the driver to prepare the transfer hardware
354 * by issuing this call
355 * @transfer_one_message: the subsystem calls the driver to transfer a single
356 * message while queuing transfers that arrive in the meantime. When the
357 * driver is finished with this message, it must call
358 * spi_finalize_current_message() so the subsystem can issue the next
Baruch Siache9305332014-01-25 22:36:15 +0200359 * message
Randy Dunlapdbabe0d2012-04-17 17:03:50 -0700360 * @unprepare_transfer_hardware: there are currently no more messages on the
Linus Walleijffbbdd212012-02-22 10:05:38 +0100361 * queue so the subsystem notifies the driver that it may relax the
362 * hardware by issuing this call
Geert Uytterhoevenbd6857a2014-01-21 16:10:07 +0100363 * @set_cs: set the logic level of the chip select line. May be called
Mark Brownb1589352013-10-05 11:50:40 +0100364 * from interrupt context.
Mark Brown2841a5f2013-10-05 00:23:12 +0100365 * @prepare_message: set up the controller to transfer a single message,
366 * for example doing DMA mapping. Called from threaded
367 * context.
Geert Uytterhoeven05167122014-01-21 16:10:06 +0100368 * @transfer_one: transfer a single spi_transfer.
369 * - return 0 if the transfer is finished,
370 * - return 1 if the transfer is still in progress. When
371 * the driver is finished with this transfer it must
372 * call spi_finalize_current_transfer() so the subsystem
Baruch Siach6e5f5262014-01-25 22:36:13 +0200373 * can issue the next transfer. Note: transfer_one and
374 * transfer_one_message are mutually exclusive; when both
375 * are set, the generic subsystem does not call your
376 * transfer_one callback.
Geert Uytterhoevenff61eb42015-04-07 20:39:19 +0200377 * @handle_err: the subsystem calls the driver to handle an error that occurs
Andy Shevchenkob716c4f2015-02-27 17:34:15 +0200378 * in the generic implementation of transfer_one_message().
Boris Brezillonc36ff262018-04-26 18:18:14 +0200379 * @mem_ops: optimized/dedicated operations for interactions with SPI memory.
380 * This field is optional and should only be implemented if the
381 * controller has native support for memory like operations.
Mark Brown2841a5f2013-10-05 00:23:12 +0100382 * @unprepare_message: undo any work done by prepare_message().
Geert Uytterhoeven6c364062017-05-22 15:11:41 +0200383 * @slave_abort: abort the ongoing transfer request on an SPI slave controller
Linus Walleijf3186dd2019-01-07 16:51:50 +0100384 * @cs_gpios: LEGACY: array of GPIO descs to use as chip select lines; one per
385 * CS number. Any individual value may be -ENOENT for CS lines that
386 * are not GPIOs (driven by the SPI controller itself). Use the cs_gpiods
387 * in new drivers.
388 * @cs_gpiods: Array of GPIO descs to use as chip select lines; one per CS
389 * number. Any individual value may be NULL for CS lines that
Andreas Larsson095c3752013-01-29 15:53:41 +0100390 * are not GPIOs (driven by the SPI controller itself).
Linus Walleijf3186dd2019-01-07 16:51:50 +0100391 * @use_gpio_descriptors: Turns on the code in the SPI core to parse and grab
392 * GPIO descriptors rather than using global GPIO numbers grabbed by the
393 * driver. This will fill in @cs_gpiods and @cs_gpios should not be used,
394 * and SPI devices will have the cs_gpiod assigned rather than cs_gpio.
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200395 * @statistics: statistics for the spi_controller
Thierry Reding2c675682014-08-08 13:02:36 +0200396 * @dma_tx: DMA transmit channel
397 * @dma_rx: DMA receive channel
398 * @dummy_rx: dummy receive buffer for full-duplex devices
399 * @dummy_tx: dummy transmit buffer for full-duplex devices
Mika Westerberga0a90712016-02-08 17:14:28 +0200400 * @fw_translate_cs: If the boot firmware uses different numbering scheme
401 * what Linux expects, this optional hook can be used to translate
402 * between the two.
David Brownell8ae12a02006-01-08 13:34:19 -0800403 *
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200404 * Each SPI controller can communicate with one or more @spi_device
David Brownell8ae12a02006-01-08 13:34:19 -0800405 * children. These make a small bus, sharing MOSI, MISO and SCK signals
406 * but not chip select signals. Each device may be configured to use a
407 * different clock rate, since those shared signals are ignored unless
408 * the chip is selected.
409 *
410 * The driver for an SPI controller manages access to those devices through
David Brownell33e34dc2007-05-08 00:32:21 -0700411 * a queue of spi_message transactions, copying data between CPU memory and
412 * an SPI slave device. For each such message it queues, it calls the
David Brownell8ae12a02006-01-08 13:34:19 -0800413 * message's completion function when the transaction completes.
414 */
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200415struct spi_controller {
Tony Jones49dce682007-10-16 01:27:48 -0700416 struct device dev;
David Brownell8ae12a02006-01-08 13:34:19 -0800417
Feng Tang2b9603a2010-08-02 15:52:15 +0800418 struct list_head list;
419
David Brownella020ed72006-04-03 15:49:04 -0700420 /* other than negative (== assign one dynamically), bus_num is fully
David Brownell8ae12a02006-01-08 13:34:19 -0800421 * board-specific. usually that simplifies to being SOC-specific.
David Brownella020ed72006-04-03 15:49:04 -0700422 * example: one SOC has three SPI controllers, numbered 0..2,
David Brownell8ae12a02006-01-08 13:34:19 -0800423 * and one board's schematics might show it using SPI-2. software
424 * would normally use bus_num=2 for that controller.
425 */
David Brownella020ed72006-04-03 15:49:04 -0700426 s16 bus_num;
David Brownell8ae12a02006-01-08 13:34:19 -0800427
428 /* chipselects will be integral to many controllers; some others
429 * might use board-specific GPIOs.
430 */
431 u16 num_chipselect;
432
Mike Rapoportfd5e1912009-04-06 19:00:56 -0700433 /* some SPI controllers pose alignment requirements on DMAable
434 * buffers; let protocol drivers know about these requirements.
435 */
436 u16 dma_alignment;
437
David Brownelle7db06b2009-06-17 16:26:04 -0700438 /* spi_device.mode flags understood by this controller driver */
439 u16 mode_bits;
440
Stephen Warren543bb252013-03-26 20:37:57 -0600441 /* bitmask of supported bits_per_word for transfers */
442 u32 bits_per_word_mask;
Stephen Warren2922a8d2013-05-21 20:36:34 -0600443#define SPI_BPW_MASK(bits) BIT((bits) - 1)
Stephen Warrenb6aa23c2013-08-01 16:08:57 -0600444#define SPI_BIT_MASK(bits) (((bits) == 32) ? ~0U : (BIT(bits) - 1))
Stephen Warreneca89602013-05-30 09:59:40 -0600445#define SPI_BPW_RANGE_MASK(min, max) (SPI_BIT_MASK(max) - SPI_BIT_MASK(min - 1))
Stephen Warren543bb252013-03-26 20:37:57 -0600446
Mark Browna2fd4f92013-07-10 14:57:26 +0100447 /* limits on transfer speed */
448 u32 min_speed_hz;
449 u32 max_speed_hz;
450
David Brownell70d60272009-06-30 11:41:27 -0700451 /* other constraints relevant to this driver */
452 u16 flags;
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200453#define SPI_CONTROLLER_HALF_DUPLEX BIT(0) /* can't do full duplex */
454#define SPI_CONTROLLER_NO_RX BIT(1) /* can't do buffer read */
455#define SPI_CONTROLLER_NO_TX BIT(2) /* can't do buffer write */
456#define SPI_CONTROLLER_MUST_RX BIT(3) /* requires rx */
457#define SPI_CONTROLLER_MUST_TX BIT(4) /* requires tx */
458
459#define SPI_MASTER_GPIO_SS BIT(5) /* GPIO CS must select slave */
David Brownell70d60272009-06-30 11:41:27 -0700460
Geert Uytterhoeven6c364062017-05-22 15:11:41 +0200461 /* flag indicating this is an SPI slave controller */
462 bool slave;
463
Michal Suchanek4acad4a2015-12-02 10:38:21 +0000464 /*
Heiner Kallweit5090cc6a2016-08-17 21:08:01 +0200465 * on some hardware transfer / message size may be constrained
Michal Suchanek4acad4a2015-12-02 10:38:21 +0000466 * the limit may depend on device transfer settings
467 */
468 size_t (*max_transfer_size)(struct spi_device *spi);
Heiner Kallweit5090cc6a2016-08-17 21:08:01 +0200469 size_t (*max_message_size)(struct spi_device *spi);
Michal Suchanek4acad4a2015-12-02 10:38:21 +0000470
Mark Brownef4d96e2016-07-21 23:53:31 +0100471 /* I/O mutex */
472 struct mutex io_mutex;
473
Ernst Schwabcf32b71e2010-06-28 17:49:29 -0700474 /* lock and mutex for SPI bus locking */
475 spinlock_t bus_lock_spinlock;
476 struct mutex bus_lock_mutex;
477
478 /* flag indicating that the SPI bus is locked for exclusive use */
479 bool bus_lock_flag;
480
David Brownell6e538aa2009-04-21 12:24:49 -0700481 /* Setup mode and clock, etc (spi driver may call many times).
482 *
483 * IMPORTANT: this may be called when transfers to another
484 * device are active. DO NOT UPDATE SHARED REGISTERS in ways
485 * which could break those transfers.
486 */
David Brownell8ae12a02006-01-08 13:34:19 -0800487 int (*setup)(struct spi_device *spi);
488
489 /* bidirectional bulk transfers
490 *
491 * + The transfer() method may not sleep; its main role is
492 * just to add the message to the queue.
493 * + For now there's no remove-from-queue operation, or
494 * any other request management
495 * + To a given spi_device, message queueing is pure fifo
496 *
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200497 * + The controller's main job is to process its message queue,
498 * selecting a chip (for masters), then transferring data
David Brownell8ae12a02006-01-08 13:34:19 -0800499 * + If there are multiple spi_device children, the i/o queue
500 * arbitration algorithm is unspecified (round robin, fifo,
501 * priority, reservations, preemption, etc)
502 *
503 * + Chipselect stays active during the entire message
504 * (unless modified by spi_transfer.cs_change != 0).
505 * + The message transfers use clock and SPI mode parameters
506 * previously established by setup() for this device
507 */
508 int (*transfer)(struct spi_device *spi,
509 struct spi_message *mesg);
510
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200511 /* called on release() to free memory provided by spi_controller */
Hans-Peter Nilsson0ffa0282007-02-12 00:52:45 -0800512 void (*cleanup)(struct spi_device *spi);
Linus Walleijffbbdd212012-02-22 10:05:38 +0100513
514 /*
Mark Brown99adef32014-01-16 12:22:43 +0000515 * Used to enable core support for DMA handling, if can_dma()
516 * exists and returns true then the transfer will be mapped
517 * prior to transfer_one() being called. The driver should
518 * not modify or store xfer and dma_tx and dma_rx must be set
519 * while the device is prepared.
520 */
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200521 bool (*can_dma)(struct spi_controller *ctlr,
Mark Brown99adef32014-01-16 12:22:43 +0000522 struct spi_device *spi,
523 struct spi_transfer *xfer);
524
525 /*
Linus Walleijffbbdd212012-02-22 10:05:38 +0100526 * These hooks are for drivers that want to use the generic
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200527 * controller transfer queueing mechanism. If these are used, the
Linus Walleijffbbdd212012-02-22 10:05:38 +0100528 * transfer() function above must NOT be specified by the driver.
529 * Over time we expect SPI drivers to be phased over to this API.
530 */
531 bool queued;
532 struct kthread_worker kworker;
533 struct task_struct *kworker_task;
534 struct kthread_work pump_messages;
535 spinlock_t queue_lock;
536 struct list_head queue;
537 struct spi_message *cur_msg;
Mark Brown0461a412014-12-09 21:38:05 +0000538 bool idling;
Linus Walleijffbbdd212012-02-22 10:05:38 +0100539 bool busy;
540 bool running;
541 bool rt;
Mark Brown49834de2013-07-28 14:47:02 +0100542 bool auto_runtime_pm;
Mark Brown2841a5f2013-10-05 00:23:12 +0100543 bool cur_msg_prepared;
Mark Brown99adef32014-01-16 12:22:43 +0000544 bool cur_msg_mapped;
Mark Brownb1589352013-10-05 11:50:40 +0100545 struct completion xfer_completion;
Mark Brown6ad45a22014-02-02 13:47:47 +0000546 size_t max_dma_len;
Linus Walleijffbbdd212012-02-22 10:05:38 +0100547
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200548 int (*prepare_transfer_hardware)(struct spi_controller *ctlr);
549 int (*transfer_one_message)(struct spi_controller *ctlr,
Linus Walleijffbbdd212012-02-22 10:05:38 +0100550 struct spi_message *mesg);
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200551 int (*unprepare_transfer_hardware)(struct spi_controller *ctlr);
552 int (*prepare_message)(struct spi_controller *ctlr,
Mark Brown2841a5f2013-10-05 00:23:12 +0100553 struct spi_message *message);
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200554 int (*unprepare_message)(struct spi_controller *ctlr,
Mark Brown2841a5f2013-10-05 00:23:12 +0100555 struct spi_message *message);
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200556 int (*slave_abort)(struct spi_controller *ctlr);
Mark Brown49834de2013-07-28 14:47:02 +0100557
Mark Brownb1589352013-10-05 11:50:40 +0100558 /*
559 * These hooks are for drivers that use a generic implementation
560 * of transfer_one_message() provied by the core.
561 */
562 void (*set_cs)(struct spi_device *spi, bool enable);
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200563 int (*transfer_one)(struct spi_controller *ctlr, struct spi_device *spi,
Mark Brownb1589352013-10-05 11:50:40 +0100564 struct spi_transfer *transfer);
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200565 void (*handle_err)(struct spi_controller *ctlr,
Andy Shevchenkob716c4f2015-02-27 17:34:15 +0200566 struct spi_message *message);
Mark Brownb1589352013-10-05 11:50:40 +0100567
Boris Brezillonc36ff262018-04-26 18:18:14 +0200568 /* Optimized handlers for SPI memory-like operations. */
569 const struct spi_controller_mem_ops *mem_ops;
570
Jean-Christophe PLAGNIOL-VILLARD74317982012-11-15 20:19:57 +0100571 /* gpio chip select */
572 int *cs_gpios;
Linus Walleijf3186dd2019-01-07 16:51:50 +0100573 struct gpio_desc **cs_gpiods;
574 bool use_gpio_descriptors;
Mark Brown99adef32014-01-16 12:22:43 +0000575
Martin Sperleca2ebc2015-06-22 13:00:36 +0000576 /* statistics */
577 struct spi_statistics statistics;
578
Mark Brown99adef32014-01-16 12:22:43 +0000579 /* DMA channels for use with core dmaengine helpers */
580 struct dma_chan *dma_tx;
581 struct dma_chan *dma_rx;
Mark Brown3a2eba92014-01-28 20:17:03 +0000582
583 /* dummy data for full duplex devices */
584 void *dummy_rx;
585 void *dummy_tx;
Mika Westerberga0a90712016-02-08 17:14:28 +0200586
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200587 int (*fw_translate_cs)(struct spi_controller *ctlr, unsigned cs);
David Brownell8ae12a02006-01-08 13:34:19 -0800588};
589
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200590static inline void *spi_controller_get_devdata(struct spi_controller *ctlr)
David Brownell0c8684612006-01-08 13:34:25 -0800591{
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200592 return dev_get_drvdata(&ctlr->dev);
David Brownell0c8684612006-01-08 13:34:25 -0800593}
594
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200595static inline void spi_controller_set_devdata(struct spi_controller *ctlr,
596 void *data)
David Brownell0c8684612006-01-08 13:34:25 -0800597{
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200598 dev_set_drvdata(&ctlr->dev, data);
David Brownell0c8684612006-01-08 13:34:25 -0800599}
600
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200601static inline struct spi_controller *spi_controller_get(struct spi_controller *ctlr)
David Brownell0c8684612006-01-08 13:34:25 -0800602{
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200603 if (!ctlr || !get_device(&ctlr->dev))
David Brownell0c8684612006-01-08 13:34:25 -0800604 return NULL;
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200605 return ctlr;
David Brownell0c8684612006-01-08 13:34:25 -0800606}
607
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200608static inline void spi_controller_put(struct spi_controller *ctlr)
David Brownell0c8684612006-01-08 13:34:25 -0800609{
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200610 if (ctlr)
611 put_device(&ctlr->dev);
David Brownell0c8684612006-01-08 13:34:25 -0800612}
613
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200614static inline bool spi_controller_is_slave(struct spi_controller *ctlr)
Geert Uytterhoeven6c364062017-05-22 15:11:41 +0200615{
616 return IS_ENABLED(CONFIG_SPI_SLAVE) && ctlr->slave;
617}
618
Linus Walleijffbbdd212012-02-22 10:05:38 +0100619/* PM calls that need to be issued by the driver */
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200620extern int spi_controller_suspend(struct spi_controller *ctlr);
621extern int spi_controller_resume(struct spi_controller *ctlr);
Linus Walleijffbbdd212012-02-22 10:05:38 +0100622
623/* Calls the driver make to interact with the message queue */
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200624extern struct spi_message *spi_get_next_queued_message(struct spi_controller *ctlr);
625extern void spi_finalize_current_message(struct spi_controller *ctlr);
626extern void spi_finalize_current_transfer(struct spi_controller *ctlr);
David Brownell0c8684612006-01-08 13:34:25 -0800627
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200628/* the spi driver core manages memory for the spi_controller classdev */
629extern struct spi_controller *__spi_alloc_controller(struct device *host,
630 unsigned int size, bool slave);
Geert Uytterhoeven6c364062017-05-22 15:11:41 +0200631
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200632static inline struct spi_controller *spi_alloc_master(struct device *host,
633 unsigned int size)
Geert Uytterhoeven6c364062017-05-22 15:11:41 +0200634{
635 return __spi_alloc_controller(host, size, false);
636}
637
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200638static inline struct spi_controller *spi_alloc_slave(struct device *host,
639 unsigned int size)
Geert Uytterhoeven6c364062017-05-22 15:11:41 +0200640{
641 if (!IS_ENABLED(CONFIG_SPI_SLAVE))
642 return NULL;
643
644 return __spi_alloc_controller(host, size, true);
645}
David Brownell8ae12a02006-01-08 13:34:19 -0800646
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200647extern int spi_register_controller(struct spi_controller *ctlr);
648extern int devm_spi_register_controller(struct device *dev,
649 struct spi_controller *ctlr);
650extern void spi_unregister_controller(struct spi_controller *ctlr);
David Brownell8ae12a02006-01-08 13:34:19 -0800651
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200652extern struct spi_controller *spi_busnum_to_master(u16 busnum);
David Brownell8ae12a02006-01-08 13:34:19 -0800653
Martin Sperld780c372015-12-14 15:20:18 +0000654/*
655 * SPI resource management while processing a SPI message
656 */
657
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200658typedef void (*spi_res_release_t)(struct spi_controller *ctlr,
Martin Sperld6497812016-02-18 15:53:10 +0000659 struct spi_message *msg,
660 void *res);
661
Martin Sperld780c372015-12-14 15:20:18 +0000662/**
663 * struct spi_res - spi resource management structure
664 * @entry: list entry
665 * @release: release code called prior to freeing this resource
666 * @data: extra data allocated for the specific use-case
667 *
668 * this is based on ideas from devres, but focused on life-cycle
669 * management during spi_message processing
670 */
Martin Sperld780c372015-12-14 15:20:18 +0000671struct spi_res {
672 struct list_head entry;
673 spi_res_release_t release;
674 unsigned long long data[]; /* guarantee ull alignment */
675};
676
677extern void *spi_res_alloc(struct spi_device *spi,
678 spi_res_release_t release,
679 size_t size, gfp_t gfp);
680extern void spi_res_add(struct spi_message *message, void *res);
681extern void spi_res_free(void *res);
682
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200683extern void spi_res_release(struct spi_controller *ctlr,
Martin Sperld780c372015-12-14 15:20:18 +0000684 struct spi_message *message);
685
David Brownell8ae12a02006-01-08 13:34:19 -0800686/*---------------------------------------------------------------------------*/
687
688/*
689 * I/O INTERFACE between SPI controller and protocol drivers
690 *
691 * Protocol drivers use a queue of spi_messages, each transferring data
692 * between the controller and memory buffers.
693 *
694 * The spi_messages themselves consist of a series of read+write transfer
695 * segments. Those segments always read the same number of bits as they
696 * write; but one or the other is easily ignored by passing a null buffer
697 * pointer. (This is unlike most types of I/O API, because SPI hardware
698 * is full duplex.)
699 *
700 * NOTE: Allocation of spi_transfer and spi_message memory is entirely
701 * up to the protocol driver, which guarantees the integrity of both (as
702 * well as the data buffers) for as long as the message is queued.
703 */
704
705/**
706 * struct spi_transfer - a read/write buffer pair
Vitaly Wool8275c642006-01-08 13:34:28 -0800707 * @tx_buf: data to be written (dma-safe memory), or NULL
708 * @rx_buf: data to be read (dma-safe memory), or NULL
David Brownell33e34dc2007-05-08 00:32:21 -0700709 * @tx_dma: DMA address of tx_buf, if @spi_message.is_dma_mapped
710 * @rx_dma: DMA address of rx_buf, if @spi_message.is_dma_mapped
Masanari Iidae2278672014-02-18 22:54:36 +0900711 * @tx_nbits: number of bits used for writing. If 0 the default
wangyuhangf477b7f2013-08-11 18:15:17 +0800712 * (SPI_NBITS_SINGLE) is used.
713 * @rx_nbits: number of bits used for reading. If 0 the default
714 * (SPI_NBITS_SINGLE) is used.
David Brownell8ae12a02006-01-08 13:34:19 -0800715 * @len: size of rx and tx buffers (in bytes)
Frederik Schwarzer025dfda2008-10-16 19:02:37 +0200716 * @speed_hz: Select a speed other than the device default for this
David Brownell33e34dc2007-05-08 00:32:21 -0700717 * transfer. If 0 the default (from @spi_device) is used.
Frederik Schwarzer025dfda2008-10-16 19:02:37 +0200718 * @bits_per_word: select a bits_per_word other than the device default
David Brownell33e34dc2007-05-08 00:32:21 -0700719 * for this transfer. If 0 the default (from @spi_device) is used.
David Brownell8ae12a02006-01-08 13:34:19 -0800720 * @cs_change: affects chipselect after this transfer completes
721 * @delay_usecs: microseconds to delay after this transfer before
David Brownell747d8442006-04-02 10:33:37 -0800722 * (optionally) changing the chipselect status, then starting
David Brownell33e34dc2007-05-08 00:32:21 -0700723 * the next transfer or completing this @spi_message.
Baolin Wangeeaceb82018-08-16 20:54:49 +0800724 * @word_delay: clock cycles to inter word delay after each word size
725 * (set by bits_per_word) transmission.
David Brownell33e34dc2007-05-08 00:32:21 -0700726 * @transfer_list: transfers are sequenced through @spi_message.transfers
Mark Brown6ad45a22014-02-02 13:47:47 +0000727 * @tx_sg: Scatterlist for transmit, currently not for client use
728 * @rx_sg: Scatterlist for receive, currently not for client use
David Brownell8ae12a02006-01-08 13:34:19 -0800729 *
730 * SPI transfers always write the same number of bytes as they read.
David Brownell33e34dc2007-05-08 00:32:21 -0700731 * Protocol drivers should always provide @rx_buf and/or @tx_buf.
David Brownell8ae12a02006-01-08 13:34:19 -0800732 * In some cases, they may also want to provide DMA addresses for
733 * the data being transferred; that may reduce overhead, when the
734 * underlying driver uses dma.
735 *
David Brownell4b1badf2006-12-29 16:48:39 -0800736 * If the transmit buffer is null, zeroes will be shifted out
David Brownell33e34dc2007-05-08 00:32:21 -0700737 * while filling @rx_buf. If the receive buffer is null, the data
Vitaly Wool8275c642006-01-08 13:34:28 -0800738 * shifted in will be discarded. Only "len" bytes shift out (or in).
739 * It's an error to try to shift out a partial word. (For example, by
740 * shifting out three bytes with word size of sixteen or twenty bits;
741 * the former uses two bytes per word, the latter uses four bytes.)
742 *
David Brownell80224562007-02-12 00:52:46 -0800743 * In-memory data values are always in native CPU byte order, translated
744 * from the wire byte order (big-endian except with SPI_LSB_FIRST). So
745 * for example when bits_per_word is sixteen, buffers are 2N bytes long
David Brownell33e34dc2007-05-08 00:32:21 -0700746 * (@len = 2N) and hold N sixteen bit words in CPU byte order.
David Brownell80224562007-02-12 00:52:46 -0800747 *
748 * When the word size of the SPI transfer is not a power-of-two multiple
749 * of eight bits, those in-memory words include extra bits. In-memory
750 * words are always seen by protocol drivers as right-justified, so the
751 * undefined (rx) or unused (tx) bits are always the most significant bits.
752 *
Vitaly Wool8275c642006-01-08 13:34:28 -0800753 * All SPI transfers start with the relevant chipselect active. Normally
754 * it stays selected until after the last transfer in a message. Drivers
David Brownell33e34dc2007-05-08 00:32:21 -0700755 * can affect the chipselect signal using cs_change.
David Brownell8ae12a02006-01-08 13:34:19 -0800756 *
757 * (i) If the transfer isn't the last one in the message, this flag is
758 * used to make the chipselect briefly go inactive in the middle of the
759 * message. Toggling chipselect in this way may be needed to terminate
760 * a chip command, letting a single spi_message perform all of group of
761 * chip transactions together.
762 *
763 * (ii) When the transfer is the last one in the message, the chip may
David Brownellf5a9c772007-06-16 10:16:08 -0700764 * stay selected until the next transfer. On multi-device SPI busses
765 * with nothing blocking messages going to other devices, this is just
766 * a performance hint; starting a message to another device deselects
767 * this one. But in other cases, this can be used to ensure correctness.
768 * Some devices need protocol transactions to be built from a series of
769 * spi_message submissions, where the content of one message is determined
770 * by the results of previous messages and where the whole transaction
771 * ends when the chipselect goes intactive.
David Brownell0c8684612006-01-08 13:34:25 -0800772 *
Masanari Iidae2278672014-02-18 22:54:36 +0900773 * When SPI can transfer in 1x,2x or 4x. It can get this transfer information
wangyuhangf477b7f2013-08-11 18:15:17 +0800774 * from device through @tx_nbits and @rx_nbits. In Bi-direction, these
775 * two should both be set. User can set transfer mode with SPI_NBITS_SINGLE(1x)
776 * SPI_NBITS_DUAL(2x) and SPI_NBITS_QUAD(4x) to support these three transfer.
777 *
David Brownell0c8684612006-01-08 13:34:25 -0800778 * The code that submits an spi_message (and its spi_transfers)
779 * to the lower layers is responsible for managing its memory.
780 * Zero-initialize every field you don't set up explicitly, to
Vitaly Wool8275c642006-01-08 13:34:28 -0800781 * insulate against future API updates. After you submit a message
782 * and its transfers, ignore them until its completion callback.
David Brownell8ae12a02006-01-08 13:34:19 -0800783 */
784struct spi_transfer {
785 /* it's ok if tx_buf == rx_buf (right?)
786 * for MicroWire, one buffer must be null
David Brownell0c8684612006-01-08 13:34:25 -0800787 * buffers must work with dma_*map_single() calls, unless
788 * spi_message.is_dma_mapped reports a pre-existing mapping
David Brownell8ae12a02006-01-08 13:34:19 -0800789 */
790 const void *tx_buf;
791 void *rx_buf;
792 unsigned len;
793
794 dma_addr_t tx_dma;
795 dma_addr_t rx_dma;
Mark Brown6ad45a22014-02-02 13:47:47 +0000796 struct sg_table tx_sg;
797 struct sg_table rx_sg;
David Brownell8ae12a02006-01-08 13:34:19 -0800798
799 unsigned cs_change:1;
Mark Brownd3fbd452014-01-10 17:09:53 +0000800 unsigned tx_nbits:3;
801 unsigned rx_nbits:3;
wangyuhangf477b7f2013-08-11 18:15:17 +0800802#define SPI_NBITS_SINGLE 0x01 /* 1bit transfer */
803#define SPI_NBITS_DUAL 0x02 /* 2bits transfer */
804#define SPI_NBITS_QUAD 0x04 /* 4bits transfer */
Imre Deak4cff33f2006-02-17 10:02:18 -0800805 u8 bits_per_word;
David Brownell8ae12a02006-01-08 13:34:19 -0800806 u16 delay_usecs;
Imre Deak4cff33f2006-02-17 10:02:18 -0800807 u32 speed_hz;
Baolin Wangeeaceb82018-08-16 20:54:49 +0800808 u16 word_delay;
Vitaly Wool8275c642006-01-08 13:34:28 -0800809
810 struct list_head transfer_list;
David Brownell8ae12a02006-01-08 13:34:19 -0800811};
812
813/**
814 * struct spi_message - one multi-segment SPI transaction
Vitaly Wool8275c642006-01-08 13:34:28 -0800815 * @transfers: list of transfer segments in this transaction
David Brownell8ae12a02006-01-08 13:34:19 -0800816 * @spi: SPI device to which the transaction is queued
817 * @is_dma_mapped: if true, the caller provided both dma and cpu virtual
818 * addresses for each transfer buffer
819 * @complete: called to report transaction completions
820 * @context: the argument to complete() when it's called
Thierry Reding2c675682014-08-08 13:02:36 +0200821 * @frame_length: the total number of bytes in the message
David Brownellb8852442006-01-08 13:34:23 -0800822 * @actual_length: the total number of bytes that were transferred in all
823 * successful segments
David Brownell8ae12a02006-01-08 13:34:19 -0800824 * @status: zero for success, else negative errno
825 * @queue: for use by whichever driver currently owns the message
826 * @state: for use by whichever driver currently owns the message
Martin Sperld780c372015-12-14 15:20:18 +0000827 * @resources: for resource management when the spi message is processed
David Brownell0c8684612006-01-08 13:34:25 -0800828 *
David Brownell33e34dc2007-05-08 00:32:21 -0700829 * A @spi_message is used to execute an atomic sequence of data transfers,
Vitaly Wool8275c642006-01-08 13:34:28 -0800830 * each represented by a struct spi_transfer. The sequence is "atomic"
831 * in the sense that no other spi_message may use that SPI bus until that
832 * sequence completes. On some systems, many such sequences can execute as
833 * as single programmed DMA transfer. On all systems, these messages are
834 * queued, and might complete after transactions to other devices. Messages
Marcin Bisc6331ba2015-03-01 13:49:32 +0100835 * sent to a given spi_device are always executed in FIFO order.
Vitaly Wool8275c642006-01-08 13:34:28 -0800836 *
David Brownell0c8684612006-01-08 13:34:25 -0800837 * The code that submits an spi_message (and its spi_transfers)
838 * to the lower layers is responsible for managing its memory.
839 * Zero-initialize every field you don't set up explicitly, to
Vitaly Wool8275c642006-01-08 13:34:28 -0800840 * insulate against future API updates. After you submit a message
841 * and its transfers, ignore them until its completion callback.
David Brownell8ae12a02006-01-08 13:34:19 -0800842 */
843struct spi_message {
David Brownell747d8442006-04-02 10:33:37 -0800844 struct list_head transfers;
David Brownell8ae12a02006-01-08 13:34:19 -0800845
846 struct spi_device *spi;
847
848 unsigned is_dma_mapped:1;
849
850 /* REVISIT: we might want a flag affecting the behavior of the
851 * last transfer ... allowing things like "read 16 bit length L"
852 * immediately followed by "read L bytes". Basically imposing
853 * a specific message scheduling algorithm.
854 *
855 * Some controller drivers (message-at-a-time queue processing)
856 * could provide that as their default scheduling algorithm. But
David Brownellb8852442006-01-08 13:34:23 -0800857 * others (with multi-message pipelines) could need a flag to
David Brownell8ae12a02006-01-08 13:34:19 -0800858 * tell them about such special cases.
859 */
860
861 /* completion is reported through a callback */
David Brownell747d8442006-04-02 10:33:37 -0800862 void (*complete)(void *context);
David Brownell8ae12a02006-01-08 13:34:19 -0800863 void *context;
Sourav Poddar078726c2013-07-18 15:31:25 +0530864 unsigned frame_length;
David Brownell8ae12a02006-01-08 13:34:19 -0800865 unsigned actual_length;
866 int status;
867
868 /* for optional use by whatever driver currently owns the
869 * spi_message ... between calls to spi_async and then later
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200870 * complete(), that's the spi_controller controller driver.
David Brownell8ae12a02006-01-08 13:34:19 -0800871 */
872 struct list_head queue;
873 void *state;
Martin Sperld780c372015-12-14 15:20:18 +0000874
875 /* list of spi_res reources when the spi message is processed */
876 struct list_head resources;
David Brownell8ae12a02006-01-08 13:34:19 -0800877};
878
Martin Sperl49ddedf2015-11-27 13:56:03 +0000879static inline void spi_message_init_no_memset(struct spi_message *m)
880{
881 INIT_LIST_HEAD(&m->transfers);
Martin Sperld780c372015-12-14 15:20:18 +0000882 INIT_LIST_HEAD(&m->resources);
Martin Sperl49ddedf2015-11-27 13:56:03 +0000883}
884
Vitaly Wool8275c642006-01-08 13:34:28 -0800885static inline void spi_message_init(struct spi_message *m)
886{
887 memset(m, 0, sizeof *m);
Martin Sperl49ddedf2015-11-27 13:56:03 +0000888 spi_message_init_no_memset(m);
Vitaly Wool8275c642006-01-08 13:34:28 -0800889}
890
891static inline void
892spi_message_add_tail(struct spi_transfer *t, struct spi_message *m)
893{
894 list_add_tail(&t->transfer_list, &m->transfers);
895}
896
897static inline void
898spi_transfer_del(struct spi_transfer *t)
899{
900 list_del(&t->transfer_list);
901}
902
Lars-Peter Clausen6d9eecd2013-01-09 17:31:00 +0000903/**
904 * spi_message_init_with_transfers - Initialize spi_message and append transfers
905 * @m: spi_message to be initialized
906 * @xfers: An array of spi transfers
907 * @num_xfers: Number of items in the xfer array
908 *
909 * This function initializes the given spi_message and adds each spi_transfer in
910 * the given array to the message.
911 */
912static inline void
913spi_message_init_with_transfers(struct spi_message *m,
914struct spi_transfer *xfers, unsigned int num_xfers)
915{
916 unsigned int i;
917
918 spi_message_init(m);
919 for (i = 0; i < num_xfers; ++i)
920 spi_message_add_tail(&xfers[i], m);
921}
922
David Brownell0c8684612006-01-08 13:34:25 -0800923/* It's fine to embed message and transaction structures in other data
924 * structures so long as you don't free them while they're in use.
925 */
926
927static inline struct spi_message *spi_message_alloc(unsigned ntrans, gfp_t flags)
928{
929 struct spi_message *m;
930
931 m = kzalloc(sizeof(struct spi_message)
932 + ntrans * sizeof(struct spi_transfer),
933 flags);
934 if (m) {
Shubhrajyoti D8f536022012-02-27 19:29:05 +0530935 unsigned i;
Vitaly Wool8275c642006-01-08 13:34:28 -0800936 struct spi_transfer *t = (struct spi_transfer *)(m + 1);
937
Emiliano Ingrassiaed77d6b2017-03-28 09:49:29 +0200938 spi_message_init_no_memset(m);
Vitaly Wool8275c642006-01-08 13:34:28 -0800939 for (i = 0; i < ntrans; i++, t++)
940 spi_message_add_tail(t, m);
David Brownell0c8684612006-01-08 13:34:25 -0800941 }
942 return m;
943}
944
945static inline void spi_message_free(struct spi_message *m)
946{
947 kfree(m);
948}
949
David Brownell7d077192009-06-17 16:26:03 -0700950extern int spi_setup(struct spi_device *spi);
David Brownell568d0692009-09-22 16:46:18 -0700951extern int spi_async(struct spi_device *spi, struct spi_message *message);
Ernst Schwabcf32b71e2010-06-28 17:49:29 -0700952extern int spi_async_locked(struct spi_device *spi,
953 struct spi_message *message);
Geert Uytterhoeven6c364062017-05-22 15:11:41 +0200954extern int spi_slave_abort(struct spi_device *spi);
David Brownell8ae12a02006-01-08 13:34:19 -0800955
Michal Suchanek4acad4a2015-12-02 10:38:21 +0000956static inline size_t
Heiner Kallweit5090cc6a2016-08-17 21:08:01 +0200957spi_max_message_size(struct spi_device *spi)
958{
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200959 struct spi_controller *ctlr = spi->controller;
960
961 if (!ctlr->max_message_size)
Heiner Kallweit5090cc6a2016-08-17 21:08:01 +0200962 return SIZE_MAX;
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200963 return ctlr->max_message_size(spi);
Heiner Kallweit5090cc6a2016-08-17 21:08:01 +0200964}
965
966static inline size_t
Michal Suchanek4acad4a2015-12-02 10:38:21 +0000967spi_max_transfer_size(struct spi_device *spi)
968{
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200969 struct spi_controller *ctlr = spi->controller;
Heiner Kallweit5090cc6a2016-08-17 21:08:01 +0200970 size_t tr_max = SIZE_MAX;
971 size_t msg_max = spi_max_message_size(spi);
972
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200973 if (ctlr->max_transfer_size)
974 tr_max = ctlr->max_transfer_size(spi);
Heiner Kallweit5090cc6a2016-08-17 21:08:01 +0200975
976 /* transfer size limit must not be greater than messsage size limit */
977 return min(tr_max, msg_max);
Michal Suchanek4acad4a2015-12-02 10:38:21 +0000978}
979
David Brownell8ae12a02006-01-08 13:34:19 -0800980/*---------------------------------------------------------------------------*/
981
Martin Sperl523baf5a2015-12-14 15:20:19 +0000982/* SPI transfer replacement methods which make use of spi_res */
983
Javier Martinez Canillasc76d9ae2016-03-10 15:01:13 -0300984struct spi_replaced_transfers;
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200985typedef void (*spi_replaced_release_t)(struct spi_controller *ctlr,
Javier Martinez Canillasc76d9ae2016-03-10 15:01:13 -0300986 struct spi_message *msg,
987 struct spi_replaced_transfers *res);
Martin Sperl523baf5a2015-12-14 15:20:19 +0000988/**
989 * struct spi_replaced_transfers - structure describing the spi_transfer
990 * replacements that have occurred
991 * so that they can get reverted
992 * @release: some extra release code to get executed prior to
993 * relasing this structure
994 * @extradata: pointer to some extra data if requested or NULL
995 * @replaced_transfers: transfers that have been replaced and which need
996 * to get restored
997 * @replaced_after: the transfer after which the @replaced_transfers
998 * are to get re-inserted
999 * @inserted: number of transfers inserted
1000 * @inserted_transfers: array of spi_transfers of array-size @inserted,
1001 * that have been replacing replaced_transfers
1002 *
1003 * note: that @extradata will point to @inserted_transfers[@inserted]
1004 * if some extra allocation is requested, so alignment will be the same
1005 * as for spi_transfers
1006 */
Martin Sperl523baf5a2015-12-14 15:20:19 +00001007struct spi_replaced_transfers {
1008 spi_replaced_release_t release;
1009 void *extradata;
1010 struct list_head replaced_transfers;
1011 struct list_head *replaced_after;
1012 size_t inserted;
1013 struct spi_transfer inserted_transfers[];
1014};
1015
1016extern struct spi_replaced_transfers *spi_replace_transfers(
1017 struct spi_message *msg,
1018 struct spi_transfer *xfer_first,
1019 size_t remove,
1020 size_t insert,
1021 spi_replaced_release_t release,
1022 size_t extradatasize,
1023 gfp_t gfp);
1024
1025/*---------------------------------------------------------------------------*/
1026
Martin Sperld9f12122015-12-14 15:20:20 +00001027/* SPI transfer transformation methods */
1028
Geert Uytterhoeven8caab752017-06-13 13:23:52 +02001029extern int spi_split_transfers_maxsize(struct spi_controller *ctlr,
Martin Sperld9f12122015-12-14 15:20:20 +00001030 struct spi_message *msg,
1031 size_t maxsize,
1032 gfp_t gfp);
1033
1034/*---------------------------------------------------------------------------*/
1035
David Brownell8ae12a02006-01-08 13:34:19 -08001036/* All these synchronous SPI transfer routines are utilities layered
1037 * over the core async transfer primitive. Here, "synchronous" means
1038 * they will sleep uninterruptibly until the async transfer completes.
1039 */
1040
1041extern int spi_sync(struct spi_device *spi, struct spi_message *message);
Ernst Schwabcf32b71e2010-06-28 17:49:29 -07001042extern int spi_sync_locked(struct spi_device *spi, struct spi_message *message);
Geert Uytterhoeven8caab752017-06-13 13:23:52 +02001043extern int spi_bus_lock(struct spi_controller *ctlr);
1044extern int spi_bus_unlock(struct spi_controller *ctlr);
David Brownell8ae12a02006-01-08 13:34:19 -08001045
1046/**
Lars-Peter Clausen6d9eecd2013-01-09 17:31:00 +00001047 * spi_sync_transfer - synchronous SPI data transfer
1048 * @spi: device with which data will be exchanged
1049 * @xfers: An array of spi_transfers
1050 * @num_xfers: Number of items in the xfer array
1051 * Context: can sleep
1052 *
1053 * Does a synchronous SPI data transfer of the given spi_transfer array.
1054 *
1055 * For more specific semantics see spi_sync().
1056 *
Javier Martinez Canillasa1fdeaa2015-10-22 18:59:22 +02001057 * Return: Return: zero on success, else a negative error code.
Lars-Peter Clausen6d9eecd2013-01-09 17:31:00 +00001058 */
1059static inline int
1060spi_sync_transfer(struct spi_device *spi, struct spi_transfer *xfers,
1061 unsigned int num_xfers)
1062{
1063 struct spi_message msg;
1064
1065 spi_message_init_with_transfers(&msg, xfers, num_xfers);
1066
1067 return spi_sync(spi, &msg);
1068}
1069
Geert Uytterhoeven323117a2016-09-13 15:38:25 +02001070/**
1071 * spi_write - SPI synchronous write
1072 * @spi: device to which data will be written
1073 * @buf: data buffer
1074 * @len: data buffer size
1075 * Context: can sleep
1076 *
1077 * This function writes the buffer @buf.
1078 * Callable only from contexts that can sleep.
1079 *
1080 * Return: zero on success, else a negative error code.
1081 */
1082static inline int
1083spi_write(struct spi_device *spi, const void *buf, size_t len)
1084{
1085 struct spi_transfer t = {
1086 .tx_buf = buf,
1087 .len = len,
1088 };
1089
1090 return spi_sync_transfer(spi, &t, 1);
1091}
1092
1093/**
1094 * spi_read - SPI synchronous read
1095 * @spi: device from which data will be read
1096 * @buf: data buffer
1097 * @len: data buffer size
1098 * Context: can sleep
1099 *
1100 * This function reads the buffer @buf.
1101 * Callable only from contexts that can sleep.
1102 *
1103 * Return: zero on success, else a negative error code.
1104 */
1105static inline int
1106spi_read(struct spi_device *spi, void *buf, size_t len)
1107{
1108 struct spi_transfer t = {
1109 .rx_buf = buf,
1110 .len = len,
1111 };
1112
1113 return spi_sync_transfer(spi, &t, 1);
1114}
1115
David Brownell0c8684612006-01-08 13:34:25 -08001116/* this copies txbuf and rxbuf data; for small transfers only! */
David Brownell8ae12a02006-01-08 13:34:19 -08001117extern int spi_write_then_read(struct spi_device *spi,
Mark Brown0c4a1592011-05-11 00:09:30 +02001118 const void *txbuf, unsigned n_tx,
1119 void *rxbuf, unsigned n_rx);
David Brownell8ae12a02006-01-08 13:34:19 -08001120
1121/**
1122 * spi_w8r8 - SPI synchronous 8 bit write followed by 8 bit read
1123 * @spi: device with which data will be exchanged
1124 * @cmd: command to be written before data is read back
David Brownell33e34dc2007-05-08 00:32:21 -07001125 * Context: can sleep
David Brownell8ae12a02006-01-08 13:34:19 -08001126 *
Javier Martinez Canillasa1fdeaa2015-10-22 18:59:22 +02001127 * Callable only from contexts that can sleep.
1128 *
1129 * Return: the (unsigned) eight bit number returned by the
1130 * device, or else a negative error code.
David Brownell8ae12a02006-01-08 13:34:19 -08001131 */
1132static inline ssize_t spi_w8r8(struct spi_device *spi, u8 cmd)
1133{
1134 ssize_t status;
1135 u8 result;
1136
1137 status = spi_write_then_read(spi, &cmd, 1, &result, 1);
1138
1139 /* return negative errno or unsigned value */
1140 return (status < 0) ? status : result;
1141}
1142
1143/**
1144 * spi_w8r16 - SPI synchronous 8 bit write followed by 16 bit read
1145 * @spi: device with which data will be exchanged
1146 * @cmd: command to be written before data is read back
David Brownell33e34dc2007-05-08 00:32:21 -07001147 * Context: can sleep
David Brownell8ae12a02006-01-08 13:34:19 -08001148 *
David Brownell8ae12a02006-01-08 13:34:19 -08001149 * The number is returned in wire-order, which is at least sometimes
1150 * big-endian.
Javier Martinez Canillasa1fdeaa2015-10-22 18:59:22 +02001151 *
1152 * Callable only from contexts that can sleep.
1153 *
1154 * Return: the (unsigned) sixteen bit number returned by the
1155 * device, or else a negative error code.
David Brownell8ae12a02006-01-08 13:34:19 -08001156 */
1157static inline ssize_t spi_w8r16(struct spi_device *spi, u8 cmd)
1158{
1159 ssize_t status;
1160 u16 result;
1161
Geert Uytterhoeven269ccca2014-01-12 13:59:06 +01001162 status = spi_write_then_read(spi, &cmd, 1, &result, 2);
David Brownell8ae12a02006-01-08 13:34:19 -08001163
1164 /* return negative errno or unsigned value */
1165 return (status < 0) ? status : result;
1166}
1167
Lars-Peter Clausen05071aa2013-09-27 16:34:27 +02001168/**
1169 * spi_w8r16be - SPI synchronous 8 bit write followed by 16 bit big-endian read
1170 * @spi: device with which data will be exchanged
1171 * @cmd: command to be written before data is read back
1172 * Context: can sleep
1173 *
Lars-Peter Clausen05071aa2013-09-27 16:34:27 +02001174 * This function is similar to spi_w8r16, with the exception that it will
1175 * convert the read 16 bit data word from big-endian to native endianness.
1176 *
Javier Martinez Canillasa1fdeaa2015-10-22 18:59:22 +02001177 * Callable only from contexts that can sleep.
1178 *
1179 * Return: the (unsigned) sixteen bit number returned by the device in cpu
1180 * endianness, or else a negative error code.
Lars-Peter Clausen05071aa2013-09-27 16:34:27 +02001181 */
1182static inline ssize_t spi_w8r16be(struct spi_device *spi, u8 cmd)
1183
1184{
1185 ssize_t status;
1186 __be16 result;
1187
1188 status = spi_write_then_read(spi, &cmd, 1, &result, 2);
1189 if (status < 0)
1190 return status;
1191
1192 return be16_to_cpu(result);
1193}
1194
David Brownell8ae12a02006-01-08 13:34:19 -08001195/*---------------------------------------------------------------------------*/
1196
1197/*
1198 * INTERFACE between board init code and SPI infrastructure.
1199 *
1200 * No SPI driver ever sees these SPI device table segments, but
1201 * it's how the SPI core (or adapters that get hotplugged) grows
1202 * the driver model tree.
1203 *
1204 * As a rule, SPI devices can't be probed. Instead, board init code
1205 * provides a table listing the devices which are present, with enough
1206 * information to bind and set up the device's driver. There's basic
1207 * support for nonstatic configurations too; enough to handle adding
1208 * parport adapters, or microcontrollers acting as USB-to-SPI bridges.
1209 */
1210
David Brownell2604288f2007-07-31 00:39:44 -07001211/**
1212 * struct spi_board_info - board-specific template for a SPI device
1213 * @modalias: Initializes spi_device.modalias; identifies the driver.
1214 * @platform_data: Initializes spi_device.platform_data; the particular
1215 * data stored there is driver-specific.
Dmitry Torokhov826cf172017-02-28 14:25:18 -08001216 * @properties: Additional device properties for the device.
David Brownell2604288f2007-07-31 00:39:44 -07001217 * @controller_data: Initializes spi_device.controller_data; some
1218 * controllers need hints about hardware setup, e.g. for DMA.
1219 * @irq: Initializes spi_device.irq; depends on how the board is wired.
1220 * @max_speed_hz: Initializes spi_device.max_speed_hz; based on limits
1221 * from the chip datasheet and board-specific signal quality issues.
Geert Uytterhoeven8caab752017-06-13 13:23:52 +02001222 * @bus_num: Identifies which spi_controller parents the spi_device; unused
David Brownell2604288f2007-07-31 00:39:44 -07001223 * by spi_new_device(), and otherwise depends on board wiring.
1224 * @chip_select: Initializes spi_device.chip_select; depends on how
1225 * the board is wired.
1226 * @mode: Initializes spi_device.mode; based on the chip datasheet, board
1227 * wiring (some devices support both 3WIRE and standard modes), and
1228 * possibly presence of an inverter in the chipselect path.
1229 *
1230 * When adding new SPI devices to the device tree, these structures serve
1231 * as a partial device template. They hold information which can't always
1232 * be determined by drivers. Information that probe() can establish (such
1233 * as the default transfer wordsize) is not included here.
1234 *
1235 * These structures are used in two places. Their primary role is to
1236 * be stored in tables of board-specific device descriptors, which are
1237 * declared early in board initialization and then used (much later) to
1238 * populate a controller's device tree after the that controller's driver
1239 * initializes. A secondary (and atypical) role is as a parameter to
1240 * spi_new_device() call, which happens after those controller drivers
1241 * are active in some dynamic board configuration models.
1242 */
David Brownell8ae12a02006-01-08 13:34:19 -08001243struct spi_board_info {
1244 /* the device name and module name are coupled, like platform_bus;
1245 * "modalias" is normally the driver name.
1246 *
1247 * platform_data goes to spi_device.dev.platform_data,
David Brownellb8852442006-01-08 13:34:23 -08001248 * controller_data goes to spi_device.controller_data,
Dmitry Torokhov826cf172017-02-28 14:25:18 -08001249 * device properties are copied and attached to spi_device,
David Brownell8ae12a02006-01-08 13:34:19 -08001250 * irq is copied too
1251 */
Anton Vorontsov75368bf2009-09-22 16:46:04 -07001252 char modalias[SPI_NAME_SIZE];
David Brownell8ae12a02006-01-08 13:34:19 -08001253 const void *platform_data;
Dmitry Torokhov826cf172017-02-28 14:25:18 -08001254 const struct property_entry *properties;
David Brownellb8852442006-01-08 13:34:23 -08001255 void *controller_data;
David Brownell8ae12a02006-01-08 13:34:19 -08001256 int irq;
1257
1258 /* slower signaling on noisy or low voltage boards */
1259 u32 max_speed_hz;
1260
1261
1262 /* bus_num is board specific and matches the bus_num of some
Geert Uytterhoeven8caab752017-06-13 13:23:52 +02001263 * spi_controller that will probably be registered later.
David Brownell8ae12a02006-01-08 13:34:19 -08001264 *
1265 * chip_select reflects how this chip is wired to that master;
1266 * it's less than num_chipselect.
1267 */
1268 u16 bus_num;
1269 u16 chip_select;
1270
David Brownell980a01c2006-06-28 07:47:15 -07001271 /* mode becomes spi_device.mode, and is essential for chips
1272 * where the default of SPI_CS_HIGH = 0 is wrong.
1273 */
wangyuhangf477b7f2013-08-11 18:15:17 +08001274 u16 mode;
David Brownell980a01c2006-06-28 07:47:15 -07001275
David Brownell8ae12a02006-01-08 13:34:19 -08001276 /* ... may need additional spi_device chip config data here.
1277 * avoid stuff protocol drivers can set; but include stuff
1278 * needed to behave without being bound to a driver:
David Brownell8ae12a02006-01-08 13:34:19 -08001279 * - quirks like clock rate mattering when not selected
1280 */
1281};
1282
1283#ifdef CONFIG_SPI
1284extern int
1285spi_register_board_info(struct spi_board_info const *info, unsigned n);
1286#else
1287/* board init code may ignore whether SPI is configured or not */
1288static inline int
1289spi_register_board_info(struct spi_board_info const *info, unsigned n)
1290 { return 0; }
1291#endif
1292
David Brownell8ae12a02006-01-08 13:34:19 -08001293/* If you're hotplugging an adapter with devices (parport, usb, etc)
David Brownell0c8684612006-01-08 13:34:25 -08001294 * use spi_new_device() to describe each device. You can also call
1295 * spi_unregister_device() to start making that device vanish, but
Geert Uytterhoeven8caab752017-06-13 13:23:52 +02001296 * normally that would be handled by spi_unregister_controller().
Grant Likelydc87c982008-05-15 16:50:22 -06001297 *
1298 * You can also use spi_alloc_device() and spi_add_device() to use a two
1299 * stage registration sequence for each spi_device. This gives the caller
1300 * some more control over the spi_device structure before it is registered,
1301 * but requires that caller to initialize fields that would otherwise
1302 * be defined using the board info.
David Brownell8ae12a02006-01-08 13:34:19 -08001303 */
1304extern struct spi_device *
Geert Uytterhoeven8caab752017-06-13 13:23:52 +02001305spi_alloc_device(struct spi_controller *ctlr);
Grant Likelydc87c982008-05-15 16:50:22 -06001306
1307extern int
1308spi_add_device(struct spi_device *spi);
1309
1310extern struct spi_device *
Geert Uytterhoeven8caab752017-06-13 13:23:52 +02001311spi_new_device(struct spi_controller *, struct spi_board_info *);
David Brownell8ae12a02006-01-08 13:34:19 -08001312
Geert Uytterhoeven3b1884c2015-11-30 15:28:06 +01001313extern void spi_unregister_device(struct spi_device *spi);
David Brownell8ae12a02006-01-08 13:34:19 -08001314
Anton Vorontsov75368bf2009-09-22 16:46:04 -07001315extern const struct spi_device_id *
1316spi_get_device_id(const struct spi_device *sdev);
1317
Beniamino Galvanib6713582014-11-22 16:21:39 +01001318static inline bool
Geert Uytterhoeven8caab752017-06-13 13:23:52 +02001319spi_transfer_is_last(struct spi_controller *ctlr, struct spi_transfer *xfer)
Beniamino Galvanib6713582014-11-22 16:21:39 +01001320{
Geert Uytterhoeven8caab752017-06-13 13:23:52 +02001321 return list_is_last(&xfer->transfer_list, &ctlr->cur_msg->transfers);
Beniamino Galvanib6713582014-11-22 16:21:39 +01001322}
1323
Marco Felsch5f143af2018-09-25 11:42:29 +02001324/* OF support code */
1325#if IS_ENABLED(CONFIG_OF)
1326
1327/* must call put_device() when done with returned spi_device device */
1328extern struct spi_device *
1329of_find_spi_device_by_node(struct device_node *node);
1330
1331#else
1332
1333static inline struct spi_device *
1334of_find_spi_device_by_node(struct device_node *node)
1335{
1336 return NULL;
1337}
1338
1339#endif /* IS_ENABLED(CONFIG_OF) */
Geert Uytterhoeven8caab752017-06-13 13:23:52 +02001340
1341/* Compatibility layer */
1342#define spi_master spi_controller
1343
1344#define SPI_MASTER_HALF_DUPLEX SPI_CONTROLLER_HALF_DUPLEX
1345#define SPI_MASTER_NO_RX SPI_CONTROLLER_NO_RX
1346#define SPI_MASTER_NO_TX SPI_CONTROLLER_NO_TX
1347#define SPI_MASTER_MUST_RX SPI_CONTROLLER_MUST_RX
1348#define SPI_MASTER_MUST_TX SPI_CONTROLLER_MUST_TX
1349
1350#define spi_master_get_devdata(_ctlr) spi_controller_get_devdata(_ctlr)
1351#define spi_master_set_devdata(_ctlr, _data) \
1352 spi_controller_set_devdata(_ctlr, _data)
1353#define spi_master_get(_ctlr) spi_controller_get(_ctlr)
1354#define spi_master_put(_ctlr) spi_controller_put(_ctlr)
1355#define spi_master_suspend(_ctlr) spi_controller_suspend(_ctlr)
1356#define spi_master_resume(_ctlr) spi_controller_resume(_ctlr)
1357
1358#define spi_register_master(_ctlr) spi_register_controller(_ctlr)
1359#define devm_spi_register_master(_dev, _ctlr) \
1360 devm_spi_register_controller(_dev, _ctlr)
1361#define spi_unregister_master(_ctlr) spi_unregister_controller(_ctlr)
1362
David Brownell8ae12a02006-01-08 13:34:19 -08001363#endif /* __LINUX_SPI_H */