blob: a7e0bbed738c7ff0a3c975fda14ec3296a9b8b49 [file] [log] [blame]
David Brownell8ae12a02006-01-08 13:34:19 -08001/*
2 * Copyright (C) 2005 David Brownell
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
David Brownell8ae12a02006-01-08 13:34:19 -080013 */
14
15#ifndef __LINUX_SPI_H
16#define __LINUX_SPI_H
17
Randy Dunlap0a30c5c2009-01-04 12:00:47 -080018#include <linux/device.h>
Anton Vorontsov75368bf2009-09-22 16:46:04 -070019#include <linux/mod_devicetable.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090020#include <linux/slab.h>
Linus Walleijffbbdd212012-02-22 10:05:38 +010021#include <linux/kthread.h>
Mark Brownb1589352013-10-05 11:50:40 +010022#include <linux/completion.h>
Mark Brown6ad45a22014-02-02 13:47:47 +000023#include <linux/scatterlist.h>
Randy Dunlap0a30c5c2009-01-04 12:00:47 -080024
Mark Brown99adef32014-01-16 12:22:43 +000025struct dma_chan;
Dmitry Torokhov826cf172017-02-28 14:25:18 -080026struct property_entry;
Geert Uytterhoeven8caab752017-06-13 13:23:52 +020027struct spi_controller;
Martin Sperleca2ebc2015-06-22 13:00:36 +000028struct spi_transfer;
Vignesh R556351f2015-12-11 09:39:56 +053029struct spi_flash_read_message;
Boris Brezillonc36ff262018-04-26 18:18:14 +020030struct spi_controller_mem_ops;
David Brownellb8852442006-01-08 13:34:23 -080031
David Brownell8ae12a02006-01-08 13:34:19 -080032/*
Geert Uytterhoeven6c364062017-05-22 15:11:41 +020033 * INTERFACES between SPI master-side drivers and SPI slave protocol handlers,
34 * and SPI infrastructure.
David Brownell8ae12a02006-01-08 13:34:19 -080035 */
36extern struct bus_type spi_bus_type;
37
38/**
Martin Sperleca2ebc2015-06-22 13:00:36 +000039 * struct spi_statistics - statistics for spi transfers
Geliang Tang0243ed42015-09-15 04:59:21 -070040 * @lock: lock protecting this structure
Martin Sperleca2ebc2015-06-22 13:00:36 +000041 *
42 * @messages: number of spi-messages handled
43 * @transfers: number of spi_transfers handled
44 * @errors: number of errors during spi_transfer
45 * @timedout: number of timeouts during spi_transfer
46 *
47 * @spi_sync: number of times spi_sync is used
48 * @spi_sync_immediate:
49 * number of times spi_sync is executed immediately
50 * in calling context without queuing and scheduling
51 * @spi_async: number of times spi_async is used
52 *
53 * @bytes: number of bytes transferred to/from device
54 * @bytes_tx: number of bytes sent to device
55 * @bytes_rx: number of bytes received from device
56 *
Martin Sperl6b7bc062015-06-22 13:02:04 +000057 * @transfer_bytes_histo:
58 * transfer bytes histogramm
Martin Sperld9f12122015-12-14 15:20:20 +000059 *
60 * @transfers_split_maxsize:
61 * number of transfers that have been split because of
62 * maxsize limit
Martin Sperleca2ebc2015-06-22 13:00:36 +000063 */
64struct spi_statistics {
65 spinlock_t lock; /* lock for the whole structure */
66
67 unsigned long messages;
68 unsigned long transfers;
69 unsigned long errors;
70 unsigned long timedout;
71
72 unsigned long spi_sync;
73 unsigned long spi_sync_immediate;
74 unsigned long spi_async;
75
76 unsigned long long bytes;
77 unsigned long long bytes_rx;
78 unsigned long long bytes_tx;
79
Martin Sperl6b7bc062015-06-22 13:02:04 +000080#define SPI_STATISTICS_HISTO_SIZE 17
81 unsigned long transfer_bytes_histo[SPI_STATISTICS_HISTO_SIZE];
Martin Sperld9f12122015-12-14 15:20:20 +000082
83 unsigned long transfers_split_maxsize;
Martin Sperleca2ebc2015-06-22 13:00:36 +000084};
85
86void spi_statistics_add_transfer_stats(struct spi_statistics *stats,
87 struct spi_transfer *xfer,
Geert Uytterhoeven8caab752017-06-13 13:23:52 +020088 struct spi_controller *ctlr);
Martin Sperleca2ebc2015-06-22 13:00:36 +000089
90#define SPI_STATISTICS_ADD_TO_FIELD(stats, field, count) \
91 do { \
92 unsigned long flags; \
93 spin_lock_irqsave(&(stats)->lock, flags); \
94 (stats)->field += count; \
95 spin_unlock_irqrestore(&(stats)->lock, flags); \
96 } while (0)
97
98#define SPI_STATISTICS_INCREMENT_FIELD(stats, field) \
99 SPI_STATISTICS_ADD_TO_FIELD(stats, field, 1)
100
101/**
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200102 * struct spi_device - Controller side proxy for an SPI slave device
David Brownell8ae12a02006-01-08 13:34:19 -0800103 * @dev: Driver model representation of the device.
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200104 * @controller: SPI controller used with the device.
105 * @master: Copy of controller, for backwards compatibility.
David Brownell8ae12a02006-01-08 13:34:19 -0800106 * @max_speed_hz: Maximum clock rate to be used with this chip
107 * (on this board); may be changed by the device's driver.
Imre Deak4cff33f2006-02-17 10:02:18 -0800108 * The spi_transfer.speed_hz can override this for each transfer.
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200109 * @chip_select: Chipselect, distinguishing chips handled by @controller.
David Brownell8ae12a02006-01-08 13:34:19 -0800110 * @mode: The spi mode defines how data is clocked out and in.
111 * This may be changed by the device's driver.
David Brownell33e34dc2007-05-08 00:32:21 -0700112 * The "active low" default for chipselect mode can be overridden
113 * (by specifying SPI_CS_HIGH) as can the "MSB first" default for
114 * each word in a transfer (by specifying SPI_LSB_FIRST).
David Brownell8ae12a02006-01-08 13:34:19 -0800115 * @bits_per_word: Data transfers involve one or more words; word sizes
David Brownell747d8442006-04-02 10:33:37 -0800116 * like eight or 12 bits are common. In-memory wordsizes are
David Brownell8ae12a02006-01-08 13:34:19 -0800117 * powers of two bytes (e.g. 20 bit samples use 32 bits).
David Brownellccf77cc2006-04-03 15:46:22 -0700118 * This may be changed by the device's driver, or left at the
119 * default (0) indicating protocol words are eight bit bytes.
Imre Deak4cff33f2006-02-17 10:02:18 -0800120 * The spi_transfer.bits_per_word can override this for each transfer.
David Brownell8ae12a02006-01-08 13:34:19 -0800121 * @irq: Negative, or the number passed to request_irq() to receive
David Brownell747d8442006-04-02 10:33:37 -0800122 * interrupts from this device.
David Brownell8ae12a02006-01-08 13:34:19 -0800123 * @controller_state: Controller's runtime state
David Brownellb8852442006-01-08 13:34:23 -0800124 * @controller_data: Board-specific definitions for controller, such as
David Brownell747d8442006-04-02 10:33:37 -0800125 * FIFO initialization parameters; from board_info.controller_data
David Brownell33e34dc2007-05-08 00:32:21 -0700126 * @modalias: Name of the driver to use with this device, or an alias
127 * for that name. This appears in the sysfs "modalias" attribute
128 * for driver coldplugging, and in uevents used for hotplugging
Andreas Larsson446411e2013-02-13 14:20:25 +0100129 * @cs_gpio: gpio number of the chipselect line (optional, -ENOENT when
Geert Uytterhoeven8d26fdf2017-11-30 14:35:08 +0100130 * not using a GPIO line)
David Brownell8ae12a02006-01-08 13:34:19 -0800131 *
Martin Sperleca2ebc2015-06-22 13:00:36 +0000132 * @statistics: statistics for the spi_device
133 *
David Brownell33e34dc2007-05-08 00:32:21 -0700134 * A @spi_device is used to interchange data between an SPI slave
David Brownell8ae12a02006-01-08 13:34:19 -0800135 * (usually a discrete chip) and CPU memory.
136 *
David Brownell33e34dc2007-05-08 00:32:21 -0700137 * In @dev, the platform_data is used to hold information about this
David Brownell8ae12a02006-01-08 13:34:19 -0800138 * device that's meaningful to the device's protocol driver, but not
139 * to its controller. One example might be an identifier for a chip
David Brownell33e34dc2007-05-08 00:32:21 -0700140 * variant with slightly different functionality; another might be
141 * information about how this particular board wires the chip's pins.
David Brownell8ae12a02006-01-08 13:34:19 -0800142 */
143struct spi_device {
144 struct device dev;
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200145 struct spi_controller *controller;
146 struct spi_controller *master; /* compatibility layer */
David Brownell8ae12a02006-01-08 13:34:19 -0800147 u32 max_speed_hz;
148 u8 chip_select;
Trent Piepho89c1f60742013-12-13 18:27:44 -0800149 u8 bits_per_word;
wangyuhangf477b7f2013-08-11 18:15:17 +0800150 u16 mode;
David Brownellb8852442006-01-08 13:34:23 -0800151#define SPI_CPHA 0x01 /* clock phase */
152#define SPI_CPOL 0x02 /* clock polarity */
David Brownell0c868462006-01-08 13:34:25 -0800153#define SPI_MODE_0 (0|0) /* (original MicroWire) */
154#define SPI_MODE_1 (0|SPI_CPHA)
David Brownell8ae12a02006-01-08 13:34:19 -0800155#define SPI_MODE_2 (SPI_CPOL|0)
156#define SPI_MODE_3 (SPI_CPOL|SPI_CPHA)
David Brownellb8852442006-01-08 13:34:23 -0800157#define SPI_CS_HIGH 0x04 /* chipselect active high? */
David Brownellccf77cc2006-04-03 15:46:22 -0700158#define SPI_LSB_FIRST 0x08 /* per-word bits-on-wire */
David Brownellc06e6772007-07-17 04:04:03 -0700159#define SPI_3WIRE 0x10 /* SI/SO signals shared */
Anton Vorontsov4ef7af52007-07-31 00:38:43 -0700160#define SPI_LOOP 0x20 /* loopback mode */
David Brownellb55f6272009-06-30 11:41:26 -0700161#define SPI_NO_CS 0x40 /* 1 dev/bus, no chipselect */
162#define SPI_READY 0x80 /* slave pulls low to pause */
wangyuhangf477b7f2013-08-11 18:15:17 +0800163#define SPI_TX_DUAL 0x100 /* transmit with 2 wires */
164#define SPI_TX_QUAD 0x200 /* transmit with 4 wires */
165#define SPI_RX_DUAL 0x400 /* receive with 2 wires */
166#define SPI_RX_QUAD 0x800 /* receive with 4 wires */
David Brownell8ae12a02006-01-08 13:34:19 -0800167 int irq;
168 void *controller_state;
David Brownellb8852442006-01-08 13:34:23 -0800169 void *controller_data;
Anton Vorontsov75368bf2009-09-22 16:46:04 -0700170 char modalias[SPI_NAME_SIZE];
Jean-Christophe PLAGNIOL-VILLARD74317982012-11-15 20:19:57 +0100171 int cs_gpio; /* chip select gpio */
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
181 * - drop chipselect after each word
182 * - chipselect delays
183 * - ...
184 */
David Brownell8ae12a02006-01-08 13:34:19 -0800185};
186
187static inline struct spi_device *to_spi_device(struct device *dev)
188{
David Brownellb8852442006-01-08 13:34:23 -0800189 return dev ? container_of(dev, struct spi_device, dev) : NULL;
David Brownell8ae12a02006-01-08 13:34:19 -0800190}
191
192/* most drivers won't need to care about device refcounting */
193static inline struct spi_device *spi_dev_get(struct spi_device *spi)
194{
195 return (spi && get_device(&spi->dev)) ? spi : NULL;
196}
197
198static inline void spi_dev_put(struct spi_device *spi)
199{
200 if (spi)
201 put_device(&spi->dev);
202}
203
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200204/* ctldata is for the bus_controller driver's runtime state */
David Brownell8ae12a02006-01-08 13:34:19 -0800205static inline void *spi_get_ctldata(struct spi_device *spi)
206{
207 return spi->controller_state;
208}
209
210static inline void spi_set_ctldata(struct spi_device *spi, void *state)
211{
212 spi->controller_state = state;
213}
214
Ben Dooks9b40ff42007-02-12 00:52:41 -0800215/* device driver data */
216
217static inline void spi_set_drvdata(struct spi_device *spi, void *data)
218{
219 dev_set_drvdata(&spi->dev, data);
220}
221
222static inline void *spi_get_drvdata(struct spi_device *spi)
223{
224 return dev_get_drvdata(&spi->dev);
225}
David Brownell8ae12a02006-01-08 13:34:19 -0800226
227struct spi_message;
Mark Brownb1589352013-10-05 11:50:40 +0100228struct spi_transfer;
David Brownellb8852442006-01-08 13:34:23 -0800229
David Brownell26042882007-07-31 00:39:44 -0700230/**
231 * struct spi_driver - Host side "protocol" driver
Anton Vorontsov75368bf2009-09-22 16:46:04 -0700232 * @id_table: List of SPI devices supported by this driver
David Brownell26042882007-07-31 00:39:44 -0700233 * @probe: Binds this driver to the spi device. Drivers can verify
234 * that the device is actually present, and may need to configure
235 * characteristics (such as bits_per_word) which weren't needed for
236 * the initial configuration done during system setup.
237 * @remove: Unbinds this driver from the spi device
238 * @shutdown: Standard shutdown callback used during system state
239 * transitions such as powerdown/halt and kexec
David Brownell26042882007-07-31 00:39:44 -0700240 * @driver: SPI device drivers should initialize the name and owner
241 * field of this structure.
242 *
243 * This represents the kind of device driver that uses SPI messages to
244 * interact with the hardware at the other end of a SPI link. It's called
245 * a "protocol" driver because it works through messages rather than talking
246 * directly to SPI hardware (which is what the underlying SPI controller
247 * driver does to pass those messages). These protocols are defined in the
248 * specification for the device(s) supported by the driver.
249 *
250 * As a rule, those device protocols represent the lowest level interface
251 * supported by a driver, and it will support upper level interfaces too.
252 * Examples of such upper levels include frameworks like MTD, networking,
253 * MMC, RTC, filesystem character device nodes, and hardware monitoring.
254 */
David Brownellb8852442006-01-08 13:34:23 -0800255struct spi_driver {
Anton Vorontsov75368bf2009-09-22 16:46:04 -0700256 const struct spi_device_id *id_table;
David Brownellb8852442006-01-08 13:34:23 -0800257 int (*probe)(struct spi_device *spi);
258 int (*remove)(struct spi_device *spi);
259 void (*shutdown)(struct spi_device *spi);
David Brownellb8852442006-01-08 13:34:23 -0800260 struct device_driver driver;
261};
262
263static inline struct spi_driver *to_spi_driver(struct device_driver *drv)
264{
265 return drv ? container_of(drv, struct spi_driver, driver) : NULL;
266}
267
Andrew F. Davisca5d2482015-10-23 08:59:10 -0500268extern int __spi_register_driver(struct module *owner, struct spi_driver *sdrv);
David Brownellb8852442006-01-08 13:34:23 -0800269
David Brownell33e34dc2007-05-08 00:32:21 -0700270/**
271 * spi_unregister_driver - reverse effect of spi_register_driver
272 * @sdrv: the driver to unregister
273 * Context: can sleep
274 */
David Brownellb8852442006-01-08 13:34:23 -0800275static inline void spi_unregister_driver(struct spi_driver *sdrv)
276{
Ben Dooksddc1e972007-02-12 00:52:43 -0800277 if (sdrv)
278 driver_unregister(&sdrv->driver);
David Brownellb8852442006-01-08 13:34:23 -0800279}
280
Andrew F. Davisca5d2482015-10-23 08:59:10 -0500281/* use a define to avoid include chaining to get THIS_MODULE */
282#define spi_register_driver(driver) \
283 __spi_register_driver(THIS_MODULE, driver)
284
Lars-Peter Clausen3acbb012011-11-16 10:13:37 +0100285/**
286 * module_spi_driver() - Helper macro for registering a SPI driver
287 * @__spi_driver: spi_driver struct
288 *
289 * Helper macro for SPI drivers which do not do anything special in module
290 * init/exit. This eliminates a lot of boilerplate. Each module may only
291 * use this macro once, and calling it replaces module_init() and module_exit()
292 */
293#define module_spi_driver(__spi_driver) \
294 module_driver(__spi_driver, spi_register_driver, \
295 spi_unregister_driver)
David Brownellb8852442006-01-08 13:34:23 -0800296
David Brownell8ae12a02006-01-08 13:34:19 -0800297/**
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200298 * struct spi_controller - interface to SPI master or slave controller
Tony Jones49dce682007-10-16 01:27:48 -0700299 * @dev: device interface to this driver
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200300 * @list: link with the global spi_controller list
David Brownell8ae12a02006-01-08 13:34:19 -0800301 * @bus_num: board-specific (and often SOC-specific) identifier for a
David Brownell747d8442006-04-02 10:33:37 -0800302 * given SPI controller.
David Brownellb8852442006-01-08 13:34:23 -0800303 * @num_chipselect: chipselects are used to distinguish individual
David Brownell747d8442006-04-02 10:33:37 -0800304 * SPI slaves, and are numbered from zero to num_chipselects.
305 * each slave has a chipselect signal, but it's common that not
306 * every chipselect is connected to a slave.
Mike Rapoportfd5e1912009-04-06 19:00:56 -0700307 * @dma_alignment: SPI controller constraint on DMA buffers alignment.
Randy Dunlapb73b2552009-09-22 16:46:00 -0700308 * @mode_bits: flags understood by this controller driver
Stephen Warren543bb252013-03-26 20:37:57 -0600309 * @bits_per_word_mask: A mask indicating which values of bits_per_word are
310 * supported by the driver. Bit n indicates that a bits_per_word n+1 is
Masanari Iidae2278672014-02-18 22:54:36 +0900311 * supported. If set, the SPI core will reject any transfer with an
Stephen Warren543bb252013-03-26 20:37:57 -0600312 * unsupported bits_per_word. If not set, this value is simply ignored,
313 * and it's up to the individual driver to perform any validation.
Mark Browna2fd4f92013-07-10 14:57:26 +0100314 * @min_speed_hz: Lowest supported transfer speed
315 * @max_speed_hz: Highest supported transfer speed
Randy Dunlapb73b2552009-09-22 16:46:00 -0700316 * @flags: other constraints relevant to this driver
Geert Uytterhoeven6c364062017-05-22 15:11:41 +0200317 * @slave: indicates that this is an SPI slave controller
Randy Dunlapee7683a2016-02-05 17:31:39 -0800318 * @max_transfer_size: function that returns the max transfer size for
319 * a &spi_device; may be %NULL, so the default %SIZE_MAX will be used.
Heiner Kallweit5090cc6a2016-08-17 21:08:01 +0200320 * @max_message_size: function that returns the max message size for
321 * a &spi_device; may be %NULL, so the default %SIZE_MAX will be used.
Mark Brownef4d96e2016-07-21 23:53:31 +0100322 * @io_mutex: mutex for physical bus access
Ernst Schwab5c79a5a2010-08-16 15:10:11 +0200323 * @bus_lock_spinlock: spinlock for SPI bus locking
Mark Brownef4d96e2016-07-21 23:53:31 +0100324 * @bus_lock_mutex: mutex for exclusion of multiple callers
Ernst Schwab5c79a5a2010-08-16 15:10:11 +0200325 * @bus_lock_flag: indicates that the SPI bus is locked for exclusive use
David Brownell8ae12a02006-01-08 13:34:19 -0800326 * @setup: updates the device mode and clocking records used by a
David Brownell80224562007-02-12 00:52:46 -0800327 * device's SPI controller; protocol code may call this. This
328 * must fail if an unrecognized or unsupported mode is requested.
David Brownell33e34dc2007-05-08 00:32:21 -0700329 * It's always safe to call this unless transfers are pending on
330 * the device whose settings are being modified.
David Brownell8ae12a02006-01-08 13:34:19 -0800331 * @transfer: adds a message to the controller's transfer queue.
332 * @cleanup: frees controller-specific state
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200333 * @can_dma: determine whether this controller supports DMA
334 * @queued: whether this controller is providing an internal message queue
Linus Walleijffbbdd212012-02-22 10:05:38 +0100335 * @kworker: thread struct for message pump
336 * @kworker_task: pointer to task for message pump kworker thread
337 * @pump_messages: work struct for scheduling work to the message pump
338 * @queue_lock: spinlock to syncronise access to message queue
339 * @queue: message queue
Mark Brown0461a412014-12-09 21:38:05 +0000340 * @idling: the device is entering idle state
Linus Walleijffbbdd212012-02-22 10:05:38 +0100341 * @cur_msg: the currently in-flight message
Mark Brown2841a5f2013-10-05 00:23:12 +0100342 * @cur_msg_prepared: spi_prepare_message was called for the currently
343 * in-flight message
Thierry Reding2c675682014-08-08 13:02:36 +0200344 * @cur_msg_mapped: message has been mapped for DMA
Masanari Iidae2278672014-02-18 22:54:36 +0900345 * @xfer_completion: used by core transfer_one_message()
Linus Walleijffbbdd212012-02-22 10:05:38 +0100346 * @busy: message pump is busy
347 * @running: message pump is running
348 * @rt: whether this queue is set to run as a realtime task
Mark Brown49834de2013-07-28 14:47:02 +0100349 * @auto_runtime_pm: the core should ensure a runtime PM reference is held
350 * while the hardware is prepared, using the parent
351 * device for the spidev
Mark Brown6ad45a22014-02-02 13:47:47 +0000352 * @max_dma_len: Maximum length of a DMA transfer for the device.
Linus Walleijffbbdd212012-02-22 10:05:38 +0100353 * @prepare_transfer_hardware: a message will soon arrive from the queue
354 * so the subsystem requests the driver to prepare the transfer hardware
355 * by issuing this call
356 * @transfer_one_message: the subsystem calls the driver to transfer a single
357 * message while queuing transfers that arrive in the meantime. When the
358 * driver is finished with this message, it must call
359 * spi_finalize_current_message() so the subsystem can issue the next
Baruch Siache9305332014-01-25 22:36:15 +0200360 * message
Randy Dunlapdbabe0d2012-04-17 17:03:50 -0700361 * @unprepare_transfer_hardware: there are currently no more messages on the
Linus Walleijffbbdd212012-02-22 10:05:38 +0100362 * queue so the subsystem notifies the driver that it may relax the
363 * hardware by issuing this call
Geert Uytterhoevenbd6857a2014-01-21 16:10:07 +0100364 * @set_cs: set the logic level of the chip select line. May be called
Mark Brownb1589352013-10-05 11:50:40 +0100365 * from interrupt context.
Mark Brown2841a5f2013-10-05 00:23:12 +0100366 * @prepare_message: set up the controller to transfer a single message,
367 * for example doing DMA mapping. Called from threaded
368 * context.
Geert Uytterhoeven05167122014-01-21 16:10:06 +0100369 * @transfer_one: transfer a single spi_transfer.
370 * - return 0 if the transfer is finished,
371 * - return 1 if the transfer is still in progress. When
372 * the driver is finished with this transfer it must
373 * call spi_finalize_current_transfer() so the subsystem
Baruch Siach6e5f5262014-01-25 22:36:13 +0200374 * can issue the next transfer. Note: transfer_one and
375 * transfer_one_message are mutually exclusive; when both
376 * are set, the generic subsystem does not call your
377 * transfer_one callback.
Geert Uytterhoevenff61eb42015-04-07 20:39:19 +0200378 * @handle_err: the subsystem calls the driver to handle an error that occurs
Andy Shevchenkob716c4f2015-02-27 17:34:15 +0200379 * in the generic implementation of transfer_one_message().
Boris Brezillonc36ff262018-04-26 18:18:14 +0200380 * @mem_ops: optimized/dedicated operations for interactions with SPI memory.
381 * This field is optional and should only be implemented if the
382 * controller has native support for memory like operations.
Mark Brown2841a5f2013-10-05 00:23:12 +0100383 * @unprepare_message: undo any work done by prepare_message().
Geert Uytterhoeven6c364062017-05-22 15:11:41 +0200384 * @slave_abort: abort the ongoing transfer request on an SPI slave controller
Vignesh R556351f2015-12-11 09:39:56 +0530385 * @spi_flash_read: to support spi-controller hardwares that provide
386 * accelerated interface to read from flash devices.
Vignesh R2bca3442017-04-11 17:22:24 +0530387 * @spi_flash_can_dma: analogous to can_dma() interface, but for
388 * controllers implementing spi_flash_read.
Heiner Kallweit7ba2f272016-04-23 22:47:08 +0200389 * @flash_read_supported: spi device supports flash read
Andreas Larsson095c3752013-01-29 15:53:41 +0100390 * @cs_gpios: Array of GPIOs to use as chip select lines; one per CS
Andreas Larsson446411e2013-02-13 14:20:25 +0100391 * number. Any individual value may be -ENOENT for CS lines that
Andreas Larsson095c3752013-01-29 15:53:41 +0100392 * are not GPIOs (driven by the SPI controller itself).
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200393 * @statistics: statistics for the spi_controller
Thierry Reding2c675682014-08-08 13:02:36 +0200394 * @dma_tx: DMA transmit channel
395 * @dma_rx: DMA receive channel
396 * @dummy_rx: dummy receive buffer for full-duplex devices
397 * @dummy_tx: dummy transmit buffer for full-duplex devices
Mika Westerberga0a90712016-02-08 17:14:28 +0200398 * @fw_translate_cs: If the boot firmware uses different numbering scheme
399 * what Linux expects, this optional hook can be used to translate
400 * between the two.
David Brownell8ae12a02006-01-08 13:34:19 -0800401 *
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200402 * Each SPI controller can communicate with one or more @spi_device
David Brownell8ae12a02006-01-08 13:34:19 -0800403 * children. These make a small bus, sharing MOSI, MISO and SCK signals
404 * but not chip select signals. Each device may be configured to use a
405 * different clock rate, since those shared signals are ignored unless
406 * the chip is selected.
407 *
408 * The driver for an SPI controller manages access to those devices through
David Brownell33e34dc2007-05-08 00:32:21 -0700409 * a queue of spi_message transactions, copying data between CPU memory and
410 * an SPI slave device. For each such message it queues, it calls the
David Brownell8ae12a02006-01-08 13:34:19 -0800411 * message's completion function when the transaction completes.
412 */
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200413struct spi_controller {
Tony Jones49dce682007-10-16 01:27:48 -0700414 struct device dev;
David Brownell8ae12a02006-01-08 13:34:19 -0800415
Feng Tang2b9603a2010-08-02 15:52:15 +0800416 struct list_head list;
417
David Brownella020ed72006-04-03 15:49:04 -0700418 /* other than negative (== assign one dynamically), bus_num is fully
David Brownell8ae12a02006-01-08 13:34:19 -0800419 * board-specific. usually that simplifies to being SOC-specific.
David Brownella020ed72006-04-03 15:49:04 -0700420 * example: one SOC has three SPI controllers, numbered 0..2,
David Brownell8ae12a02006-01-08 13:34:19 -0800421 * and one board's schematics might show it using SPI-2. software
422 * would normally use bus_num=2 for that controller.
423 */
David Brownella020ed72006-04-03 15:49:04 -0700424 s16 bus_num;
David Brownell8ae12a02006-01-08 13:34:19 -0800425
426 /* chipselects will be integral to many controllers; some others
427 * might use board-specific GPIOs.
428 */
429 u16 num_chipselect;
430
Mike Rapoportfd5e1912009-04-06 19:00:56 -0700431 /* some SPI controllers pose alignment requirements on DMAable
432 * buffers; let protocol drivers know about these requirements.
433 */
434 u16 dma_alignment;
435
David Brownelle7db06b2009-06-17 16:26:04 -0700436 /* spi_device.mode flags understood by this controller driver */
437 u16 mode_bits;
438
Stephen Warren543bb252013-03-26 20:37:57 -0600439 /* bitmask of supported bits_per_word for transfers */
440 u32 bits_per_word_mask;
Stephen Warren2922a8d2013-05-21 20:36:34 -0600441#define SPI_BPW_MASK(bits) BIT((bits) - 1)
Stephen Warrenb6aa23c2013-08-01 16:08:57 -0600442#define SPI_BIT_MASK(bits) (((bits) == 32) ? ~0U : (BIT(bits) - 1))
Stephen Warreneca89602013-05-30 09:59:40 -0600443#define SPI_BPW_RANGE_MASK(min, max) (SPI_BIT_MASK(max) - SPI_BIT_MASK(min - 1))
Stephen Warren543bb252013-03-26 20:37:57 -0600444
Mark Browna2fd4f92013-07-10 14:57:26 +0100445 /* limits on transfer speed */
446 u32 min_speed_hz;
447 u32 max_speed_hz;
448
David Brownell70d60272009-06-30 11:41:27 -0700449 /* other constraints relevant to this driver */
450 u16 flags;
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200451#define SPI_CONTROLLER_HALF_DUPLEX BIT(0) /* can't do full duplex */
452#define SPI_CONTROLLER_NO_RX BIT(1) /* can't do buffer read */
453#define SPI_CONTROLLER_NO_TX BIT(2) /* can't do buffer write */
454#define SPI_CONTROLLER_MUST_RX BIT(3) /* requires rx */
455#define SPI_CONTROLLER_MUST_TX BIT(4) /* requires tx */
456
457#define SPI_MASTER_GPIO_SS BIT(5) /* GPIO CS must select slave */
David Brownell70d60272009-06-30 11:41:27 -0700458
Geert Uytterhoeven6c364062017-05-22 15:11:41 +0200459 /* flag indicating this is an SPI slave controller */
460 bool slave;
461
Michal Suchanek4acad4a2015-12-02 10:38:21 +0000462 /*
Heiner Kallweit5090cc6a2016-08-17 21:08:01 +0200463 * on some hardware transfer / message size may be constrained
Michal Suchanek4acad4a2015-12-02 10:38:21 +0000464 * the limit may depend on device transfer settings
465 */
466 size_t (*max_transfer_size)(struct spi_device *spi);
Heiner Kallweit5090cc6a2016-08-17 21:08:01 +0200467 size_t (*max_message_size)(struct spi_device *spi);
Michal Suchanek4acad4a2015-12-02 10:38:21 +0000468
Mark Brownef4d96e2016-07-21 23:53:31 +0100469 /* I/O mutex */
470 struct mutex io_mutex;
471
Ernst Schwabcf32b71e2010-06-28 17:49:29 -0700472 /* lock and mutex for SPI bus locking */
473 spinlock_t bus_lock_spinlock;
474 struct mutex bus_lock_mutex;
475
476 /* flag indicating that the SPI bus is locked for exclusive use */
477 bool bus_lock_flag;
478
David Brownell6e538aa2009-04-21 12:24:49 -0700479 /* Setup mode and clock, etc (spi driver may call many times).
480 *
481 * IMPORTANT: this may be called when transfers to another
482 * device are active. DO NOT UPDATE SHARED REGISTERS in ways
483 * which could break those transfers.
484 */
David Brownell8ae12a02006-01-08 13:34:19 -0800485 int (*setup)(struct spi_device *spi);
486
487 /* bidirectional bulk transfers
488 *
489 * + The transfer() method may not sleep; its main role is
490 * just to add the message to the queue.
491 * + For now there's no remove-from-queue operation, or
492 * any other request management
493 * + To a given spi_device, message queueing is pure fifo
494 *
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200495 * + The controller's main job is to process its message queue,
496 * selecting a chip (for masters), then transferring data
David Brownell8ae12a02006-01-08 13:34:19 -0800497 * + If there are multiple spi_device children, the i/o queue
498 * arbitration algorithm is unspecified (round robin, fifo,
499 * priority, reservations, preemption, etc)
500 *
501 * + Chipselect stays active during the entire message
502 * (unless modified by spi_transfer.cs_change != 0).
503 * + The message transfers use clock and SPI mode parameters
504 * previously established by setup() for this device
505 */
506 int (*transfer)(struct spi_device *spi,
507 struct spi_message *mesg);
508
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200509 /* called on release() to free memory provided by spi_controller */
Hans-Peter Nilsson0ffa0282007-02-12 00:52:45 -0800510 void (*cleanup)(struct spi_device *spi);
Linus Walleijffbbdd212012-02-22 10:05:38 +0100511
512 /*
Mark Brown99adef32014-01-16 12:22:43 +0000513 * Used to enable core support for DMA handling, if can_dma()
514 * exists and returns true then the transfer will be mapped
515 * prior to transfer_one() being called. The driver should
516 * not modify or store xfer and dma_tx and dma_rx must be set
517 * while the device is prepared.
518 */
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200519 bool (*can_dma)(struct spi_controller *ctlr,
Mark Brown99adef32014-01-16 12:22:43 +0000520 struct spi_device *spi,
521 struct spi_transfer *xfer);
522
523 /*
Linus Walleijffbbdd212012-02-22 10:05:38 +0100524 * These hooks are for drivers that want to use the generic
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200525 * controller transfer queueing mechanism. If these are used, the
Linus Walleijffbbdd212012-02-22 10:05:38 +0100526 * transfer() function above must NOT be specified by the driver.
527 * Over time we expect SPI drivers to be phased over to this API.
528 */
529 bool queued;
530 struct kthread_worker kworker;
531 struct task_struct *kworker_task;
532 struct kthread_work pump_messages;
533 spinlock_t queue_lock;
534 struct list_head queue;
535 struct spi_message *cur_msg;
Mark Brown0461a412014-12-09 21:38:05 +0000536 bool idling;
Linus Walleijffbbdd212012-02-22 10:05:38 +0100537 bool busy;
538 bool running;
539 bool rt;
Mark Brown49834de2013-07-28 14:47:02 +0100540 bool auto_runtime_pm;
Mark Brown2841a5f2013-10-05 00:23:12 +0100541 bool cur_msg_prepared;
Mark Brown99adef32014-01-16 12:22:43 +0000542 bool cur_msg_mapped;
Mark Brownb1589352013-10-05 11:50:40 +0100543 struct completion xfer_completion;
Mark Brown6ad45a22014-02-02 13:47:47 +0000544 size_t max_dma_len;
Linus Walleijffbbdd212012-02-22 10:05:38 +0100545
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200546 int (*prepare_transfer_hardware)(struct spi_controller *ctlr);
547 int (*transfer_one_message)(struct spi_controller *ctlr,
Linus Walleijffbbdd212012-02-22 10:05:38 +0100548 struct spi_message *mesg);
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200549 int (*unprepare_transfer_hardware)(struct spi_controller *ctlr);
550 int (*prepare_message)(struct spi_controller *ctlr,
Mark Brown2841a5f2013-10-05 00:23:12 +0100551 struct spi_message *message);
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200552 int (*unprepare_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 (*slave_abort)(struct spi_controller *ctlr);
Vignesh R556351f2015-12-11 09:39:56 +0530555 int (*spi_flash_read)(struct spi_device *spi,
556 struct spi_flash_read_message *msg);
Vignesh R2bca3442017-04-11 17:22:24 +0530557 bool (*spi_flash_can_dma)(struct spi_device *spi,
558 struct spi_flash_read_message *msg);
Heiner Kallweit7ba2f272016-04-23 22:47:08 +0200559 bool (*flash_read_supported)(struct spi_device *spi);
Mark Brown49834de2013-07-28 14:47:02 +0100560
Mark Brownb1589352013-10-05 11:50:40 +0100561 /*
562 * These hooks are for drivers that use a generic implementation
563 * of transfer_one_message() provied by the core.
564 */
565 void (*set_cs)(struct spi_device *spi, bool enable);
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200566 int (*transfer_one)(struct spi_controller *ctlr, struct spi_device *spi,
Mark Brownb1589352013-10-05 11:50:40 +0100567 struct spi_transfer *transfer);
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200568 void (*handle_err)(struct spi_controller *ctlr,
Andy Shevchenkob716c4f2015-02-27 17:34:15 +0200569 struct spi_message *message);
Mark Brownb1589352013-10-05 11:50:40 +0100570
Boris Brezillonc36ff262018-04-26 18:18:14 +0200571 /* Optimized handlers for SPI memory-like operations. */
572 const struct spi_controller_mem_ops *mem_ops;
573
Jean-Christophe PLAGNIOL-VILLARD74317982012-11-15 20:19:57 +0100574 /* gpio chip select */
575 int *cs_gpios;
Mark Brown99adef32014-01-16 12:22:43 +0000576
Martin Sperleca2ebc2015-06-22 13:00:36 +0000577 /* statistics */
578 struct spi_statistics statistics;
579
Mark Brown99adef32014-01-16 12:22:43 +0000580 /* DMA channels for use with core dmaengine helpers */
581 struct dma_chan *dma_tx;
582 struct dma_chan *dma_rx;
Mark Brown3a2eba92014-01-28 20:17:03 +0000583
584 /* dummy data for full duplex devices */
585 void *dummy_rx;
586 void *dummy_tx;
Mika Westerberga0a90712016-02-08 17:14:28 +0200587
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200588 int (*fw_translate_cs)(struct spi_controller *ctlr, unsigned cs);
David Brownell8ae12a02006-01-08 13:34:19 -0800589};
590
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200591static inline void *spi_controller_get_devdata(struct spi_controller *ctlr)
David Brownell0c868462006-01-08 13:34:25 -0800592{
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200593 return dev_get_drvdata(&ctlr->dev);
David Brownell0c868462006-01-08 13:34:25 -0800594}
595
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200596static inline void spi_controller_set_devdata(struct spi_controller *ctlr,
597 void *data)
David Brownell0c868462006-01-08 13:34:25 -0800598{
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200599 dev_set_drvdata(&ctlr->dev, data);
David Brownell0c868462006-01-08 13:34:25 -0800600}
601
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200602static inline struct spi_controller *spi_controller_get(struct spi_controller *ctlr)
David Brownell0c868462006-01-08 13:34:25 -0800603{
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200604 if (!ctlr || !get_device(&ctlr->dev))
David Brownell0c868462006-01-08 13:34:25 -0800605 return NULL;
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200606 return ctlr;
David Brownell0c868462006-01-08 13:34:25 -0800607}
608
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200609static inline void spi_controller_put(struct spi_controller *ctlr)
David Brownell0c868462006-01-08 13:34:25 -0800610{
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200611 if (ctlr)
612 put_device(&ctlr->dev);
David Brownell0c868462006-01-08 13:34:25 -0800613}
614
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200615static inline bool spi_controller_is_slave(struct spi_controller *ctlr)
Geert Uytterhoeven6c364062017-05-22 15:11:41 +0200616{
617 return IS_ENABLED(CONFIG_SPI_SLAVE) && ctlr->slave;
618}
619
Linus Walleijffbbdd212012-02-22 10:05:38 +0100620/* PM calls that need to be issued by the driver */
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200621extern int spi_controller_suspend(struct spi_controller *ctlr);
622extern int spi_controller_resume(struct spi_controller *ctlr);
Linus Walleijffbbdd212012-02-22 10:05:38 +0100623
624/* Calls the driver make to interact with the message queue */
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200625extern struct spi_message *spi_get_next_queued_message(struct spi_controller *ctlr);
626extern void spi_finalize_current_message(struct spi_controller *ctlr);
627extern void spi_finalize_current_transfer(struct spi_controller *ctlr);
David Brownell0c868462006-01-08 13:34:25 -0800628
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200629/* the spi driver core manages memory for the spi_controller classdev */
630extern struct spi_controller *__spi_alloc_controller(struct device *host,
631 unsigned int size, bool slave);
Geert Uytterhoeven6c364062017-05-22 15:11:41 +0200632
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200633static inline struct spi_controller *spi_alloc_master(struct device *host,
634 unsigned int size)
Geert Uytterhoeven6c364062017-05-22 15:11:41 +0200635{
636 return __spi_alloc_controller(host, size, false);
637}
638
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200639static inline struct spi_controller *spi_alloc_slave(struct device *host,
640 unsigned int size)
Geert Uytterhoeven6c364062017-05-22 15:11:41 +0200641{
642 if (!IS_ENABLED(CONFIG_SPI_SLAVE))
643 return NULL;
644
645 return __spi_alloc_controller(host, size, true);
646}
David Brownell8ae12a02006-01-08 13:34:19 -0800647
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200648extern int spi_register_controller(struct spi_controller *ctlr);
649extern int devm_spi_register_controller(struct device *dev,
650 struct spi_controller *ctlr);
651extern void spi_unregister_controller(struct spi_controller *ctlr);
David Brownell8ae12a02006-01-08 13:34:19 -0800652
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200653extern struct spi_controller *spi_busnum_to_master(u16 busnum);
David Brownell8ae12a02006-01-08 13:34:19 -0800654
Martin Sperld780c372015-12-14 15:20:18 +0000655/*
656 * SPI resource management while processing a SPI message
657 */
658
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200659typedef void (*spi_res_release_t)(struct spi_controller *ctlr,
Martin Sperld6497812016-02-18 15:53:10 +0000660 struct spi_message *msg,
661 void *res);
662
Martin Sperld780c372015-12-14 15:20:18 +0000663/**
664 * struct spi_res - spi resource management structure
665 * @entry: list entry
666 * @release: release code called prior to freeing this resource
667 * @data: extra data allocated for the specific use-case
668 *
669 * this is based on ideas from devres, but focused on life-cycle
670 * management during spi_message processing
671 */
Martin Sperld780c372015-12-14 15:20:18 +0000672struct spi_res {
673 struct list_head entry;
674 spi_res_release_t release;
675 unsigned long long data[]; /* guarantee ull alignment */
676};
677
678extern void *spi_res_alloc(struct spi_device *spi,
679 spi_res_release_t release,
680 size_t size, gfp_t gfp);
681extern void spi_res_add(struct spi_message *message, void *res);
682extern void spi_res_free(void *res);
683
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200684extern void spi_res_release(struct spi_controller *ctlr,
Martin Sperld780c372015-12-14 15:20:18 +0000685 struct spi_message *message);
686
David Brownell8ae12a02006-01-08 13:34:19 -0800687/*---------------------------------------------------------------------------*/
688
689/*
690 * I/O INTERFACE between SPI controller and protocol drivers
691 *
692 * Protocol drivers use a queue of spi_messages, each transferring data
693 * between the controller and memory buffers.
694 *
695 * The spi_messages themselves consist of a series of read+write transfer
696 * segments. Those segments always read the same number of bits as they
697 * write; but one or the other is easily ignored by passing a null buffer
698 * pointer. (This is unlike most types of I/O API, because SPI hardware
699 * is full duplex.)
700 *
701 * NOTE: Allocation of spi_transfer and spi_message memory is entirely
702 * up to the protocol driver, which guarantees the integrity of both (as
703 * well as the data buffers) for as long as the message is queued.
704 */
705
706/**
707 * struct spi_transfer - a read/write buffer pair
Vitaly Wool8275c642006-01-08 13:34:28 -0800708 * @tx_buf: data to be written (dma-safe memory), or NULL
709 * @rx_buf: data to be read (dma-safe memory), or NULL
David Brownell33e34dc2007-05-08 00:32:21 -0700710 * @tx_dma: DMA address of tx_buf, if @spi_message.is_dma_mapped
711 * @rx_dma: DMA address of rx_buf, if @spi_message.is_dma_mapped
Masanari Iidae2278672014-02-18 22:54:36 +0900712 * @tx_nbits: number of bits used for writing. If 0 the default
wangyuhangf477b7f2013-08-11 18:15:17 +0800713 * (SPI_NBITS_SINGLE) is used.
714 * @rx_nbits: number of bits used for reading. If 0 the default
715 * (SPI_NBITS_SINGLE) is used.
David Brownell8ae12a02006-01-08 13:34:19 -0800716 * @len: size of rx and tx buffers (in bytes)
Frederik Schwarzer025dfda2008-10-16 19:02:37 +0200717 * @speed_hz: Select a speed other than the device default for this
David Brownell33e34dc2007-05-08 00:32:21 -0700718 * transfer. If 0 the default (from @spi_device) is used.
Frederik Schwarzer025dfda2008-10-16 19:02:37 +0200719 * @bits_per_word: select a bits_per_word other than the device default
David Brownell33e34dc2007-05-08 00:32:21 -0700720 * for this transfer. If 0 the default (from @spi_device) is used.
David Brownell8ae12a02006-01-08 13:34:19 -0800721 * @cs_change: affects chipselect after this transfer completes
722 * @delay_usecs: microseconds to delay after this transfer before
David Brownell747d8442006-04-02 10:33:37 -0800723 * (optionally) changing the chipselect status, then starting
David Brownell33e34dc2007-05-08 00:32:21 -0700724 * the next transfer or completing this @spi_message.
725 * @transfer_list: transfers are sequenced through @spi_message.transfers
Mark Brown6ad45a22014-02-02 13:47:47 +0000726 * @tx_sg: Scatterlist for transmit, currently not for client use
727 * @rx_sg: Scatterlist for receive, currently not for client use
David Brownell8ae12a02006-01-08 13:34:19 -0800728 *
729 * SPI transfers always write the same number of bytes as they read.
David Brownell33e34dc2007-05-08 00:32:21 -0700730 * Protocol drivers should always provide @rx_buf and/or @tx_buf.
David Brownell8ae12a02006-01-08 13:34:19 -0800731 * In some cases, they may also want to provide DMA addresses for
732 * the data being transferred; that may reduce overhead, when the
733 * underlying driver uses dma.
734 *
David Brownell4b1badf2006-12-29 16:48:39 -0800735 * If the transmit buffer is null, zeroes will be shifted out
David Brownell33e34dc2007-05-08 00:32:21 -0700736 * while filling @rx_buf. If the receive buffer is null, the data
Vitaly Wool8275c642006-01-08 13:34:28 -0800737 * shifted in will be discarded. Only "len" bytes shift out (or in).
738 * It's an error to try to shift out a partial word. (For example, by
739 * shifting out three bytes with word size of sixteen or twenty bits;
740 * the former uses two bytes per word, the latter uses four bytes.)
741 *
David Brownell80224562007-02-12 00:52:46 -0800742 * In-memory data values are always in native CPU byte order, translated
743 * from the wire byte order (big-endian except with SPI_LSB_FIRST). So
744 * for example when bits_per_word is sixteen, buffers are 2N bytes long
David Brownell33e34dc2007-05-08 00:32:21 -0700745 * (@len = 2N) and hold N sixteen bit words in CPU byte order.
David Brownell80224562007-02-12 00:52:46 -0800746 *
747 * When the word size of the SPI transfer is not a power-of-two multiple
748 * of eight bits, those in-memory words include extra bits. In-memory
749 * words are always seen by protocol drivers as right-justified, so the
750 * undefined (rx) or unused (tx) bits are always the most significant bits.
751 *
Vitaly Wool8275c642006-01-08 13:34:28 -0800752 * All SPI transfers start with the relevant chipselect active. Normally
753 * it stays selected until after the last transfer in a message. Drivers
David Brownell33e34dc2007-05-08 00:32:21 -0700754 * can affect the chipselect signal using cs_change.
David Brownell8ae12a02006-01-08 13:34:19 -0800755 *
756 * (i) If the transfer isn't the last one in the message, this flag is
757 * used to make the chipselect briefly go inactive in the middle of the
758 * message. Toggling chipselect in this way may be needed to terminate
759 * a chip command, letting a single spi_message perform all of group of
760 * chip transactions together.
761 *
762 * (ii) When the transfer is the last one in the message, the chip may
David Brownellf5a9c772007-06-16 10:16:08 -0700763 * stay selected until the next transfer. On multi-device SPI busses
764 * with nothing blocking messages going to other devices, this is just
765 * a performance hint; starting a message to another device deselects
766 * this one. But in other cases, this can be used to ensure correctness.
767 * Some devices need protocol transactions to be built from a series of
768 * spi_message submissions, where the content of one message is determined
769 * by the results of previous messages and where the whole transaction
770 * ends when the chipselect goes intactive.
David Brownell0c868462006-01-08 13:34:25 -0800771 *
Masanari Iidae2278672014-02-18 22:54:36 +0900772 * When SPI can transfer in 1x,2x or 4x. It can get this transfer information
wangyuhangf477b7f2013-08-11 18:15:17 +0800773 * from device through @tx_nbits and @rx_nbits. In Bi-direction, these
774 * two should both be set. User can set transfer mode with SPI_NBITS_SINGLE(1x)
775 * SPI_NBITS_DUAL(2x) and SPI_NBITS_QUAD(4x) to support these three transfer.
776 *
David Brownell0c868462006-01-08 13:34:25 -0800777 * The code that submits an spi_message (and its spi_transfers)
778 * to the lower layers is responsible for managing its memory.
779 * Zero-initialize every field you don't set up explicitly, to
Vitaly Wool8275c642006-01-08 13:34:28 -0800780 * insulate against future API updates. After you submit a message
781 * and its transfers, ignore them until its completion callback.
David Brownell8ae12a02006-01-08 13:34:19 -0800782 */
783struct spi_transfer {
784 /* it's ok if tx_buf == rx_buf (right?)
785 * for MicroWire, one buffer must be null
David Brownell0c868462006-01-08 13:34:25 -0800786 * buffers must work with dma_*map_single() calls, unless
787 * spi_message.is_dma_mapped reports a pre-existing mapping
David Brownell8ae12a02006-01-08 13:34:19 -0800788 */
789 const void *tx_buf;
790 void *rx_buf;
791 unsigned len;
792
793 dma_addr_t tx_dma;
794 dma_addr_t rx_dma;
Mark Brown6ad45a22014-02-02 13:47:47 +0000795 struct sg_table tx_sg;
796 struct sg_table rx_sg;
David Brownell8ae12a02006-01-08 13:34:19 -0800797
798 unsigned cs_change:1;
Mark Brownd3fbd452014-01-10 17:09:53 +0000799 unsigned tx_nbits:3;
800 unsigned rx_nbits:3;
wangyuhangf477b7f2013-08-11 18:15:17 +0800801#define SPI_NBITS_SINGLE 0x01 /* 1bit transfer */
802#define SPI_NBITS_DUAL 0x02 /* 2bits transfer */
803#define SPI_NBITS_QUAD 0x04 /* 4bits transfer */
Imre Deak4cff33f2006-02-17 10:02:18 -0800804 u8 bits_per_word;
David Brownell8ae12a02006-01-08 13:34:19 -0800805 u16 delay_usecs;
Imre Deak4cff33f2006-02-17 10:02:18 -0800806 u32 speed_hz;
Vitaly Wool8275c642006-01-08 13:34:28 -0800807
808 struct list_head transfer_list;
David Brownell8ae12a02006-01-08 13:34:19 -0800809};
810
811/**
812 * struct spi_message - one multi-segment SPI transaction
Vitaly Wool8275c642006-01-08 13:34:28 -0800813 * @transfers: list of transfer segments in this transaction
David Brownell8ae12a02006-01-08 13:34:19 -0800814 * @spi: SPI device to which the transaction is queued
815 * @is_dma_mapped: if true, the caller provided both dma and cpu virtual
816 * addresses for each transfer buffer
817 * @complete: called to report transaction completions
818 * @context: the argument to complete() when it's called
Thierry Reding2c675682014-08-08 13:02:36 +0200819 * @frame_length: the total number of bytes in the message
David Brownellb8852442006-01-08 13:34:23 -0800820 * @actual_length: the total number of bytes that were transferred in all
821 * successful segments
David Brownell8ae12a02006-01-08 13:34:19 -0800822 * @status: zero for success, else negative errno
823 * @queue: for use by whichever driver currently owns the message
824 * @state: for use by whichever driver currently owns the message
Martin Sperld780c372015-12-14 15:20:18 +0000825 * @resources: for resource management when the spi message is processed
David Brownell0c868462006-01-08 13:34:25 -0800826 *
David Brownell33e34dc2007-05-08 00:32:21 -0700827 * A @spi_message is used to execute an atomic sequence of data transfers,
Vitaly Wool8275c642006-01-08 13:34:28 -0800828 * each represented by a struct spi_transfer. The sequence is "atomic"
829 * in the sense that no other spi_message may use that SPI bus until that
830 * sequence completes. On some systems, many such sequences can execute as
831 * as single programmed DMA transfer. On all systems, these messages are
832 * queued, and might complete after transactions to other devices. Messages
Marcin Bisc6331ba2015-03-01 13:49:32 +0100833 * sent to a given spi_device are always executed in FIFO order.
Vitaly Wool8275c642006-01-08 13:34:28 -0800834 *
David Brownell0c868462006-01-08 13:34:25 -0800835 * The code that submits an spi_message (and its spi_transfers)
836 * to the lower layers is responsible for managing its memory.
837 * Zero-initialize every field you don't set up explicitly, to
Vitaly Wool8275c642006-01-08 13:34:28 -0800838 * insulate against future API updates. After you submit a message
839 * and its transfers, ignore them until its completion callback.
David Brownell8ae12a02006-01-08 13:34:19 -0800840 */
841struct spi_message {
David Brownell747d8442006-04-02 10:33:37 -0800842 struct list_head transfers;
David Brownell8ae12a02006-01-08 13:34:19 -0800843
844 struct spi_device *spi;
845
846 unsigned is_dma_mapped:1;
847
848 /* REVISIT: we might want a flag affecting the behavior of the
849 * last transfer ... allowing things like "read 16 bit length L"
850 * immediately followed by "read L bytes". Basically imposing
851 * a specific message scheduling algorithm.
852 *
853 * Some controller drivers (message-at-a-time queue processing)
854 * could provide that as their default scheduling algorithm. But
David Brownellb8852442006-01-08 13:34:23 -0800855 * others (with multi-message pipelines) could need a flag to
David Brownell8ae12a02006-01-08 13:34:19 -0800856 * tell them about such special cases.
857 */
858
859 /* completion is reported through a callback */
David Brownell747d8442006-04-02 10:33:37 -0800860 void (*complete)(void *context);
David Brownell8ae12a02006-01-08 13:34:19 -0800861 void *context;
Sourav Poddar078726c2013-07-18 15:31:25 +0530862 unsigned frame_length;
David Brownell8ae12a02006-01-08 13:34:19 -0800863 unsigned actual_length;
864 int status;
865
866 /* for optional use by whatever driver currently owns the
867 * spi_message ... between calls to spi_async and then later
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200868 * complete(), that's the spi_controller controller driver.
David Brownell8ae12a02006-01-08 13:34:19 -0800869 */
870 struct list_head queue;
871 void *state;
Martin Sperld780c372015-12-14 15:20:18 +0000872
873 /* list of spi_res reources when the spi message is processed */
874 struct list_head resources;
David Brownell8ae12a02006-01-08 13:34:19 -0800875};
876
Martin Sperl49ddedf2015-11-27 13:56:03 +0000877static inline void spi_message_init_no_memset(struct spi_message *m)
878{
879 INIT_LIST_HEAD(&m->transfers);
Martin Sperld780c372015-12-14 15:20:18 +0000880 INIT_LIST_HEAD(&m->resources);
Martin Sperl49ddedf2015-11-27 13:56:03 +0000881}
882
Vitaly Wool8275c642006-01-08 13:34:28 -0800883static inline void spi_message_init(struct spi_message *m)
884{
885 memset(m, 0, sizeof *m);
Martin Sperl49ddedf2015-11-27 13:56:03 +0000886 spi_message_init_no_memset(m);
Vitaly Wool8275c642006-01-08 13:34:28 -0800887}
888
889static inline void
890spi_message_add_tail(struct spi_transfer *t, struct spi_message *m)
891{
892 list_add_tail(&t->transfer_list, &m->transfers);
893}
894
895static inline void
896spi_transfer_del(struct spi_transfer *t)
897{
898 list_del(&t->transfer_list);
899}
900
Lars-Peter Clausen6d9eecd2013-01-09 17:31:00 +0000901/**
902 * spi_message_init_with_transfers - Initialize spi_message and append transfers
903 * @m: spi_message to be initialized
904 * @xfers: An array of spi transfers
905 * @num_xfers: Number of items in the xfer array
906 *
907 * This function initializes the given spi_message and adds each spi_transfer in
908 * the given array to the message.
909 */
910static inline void
911spi_message_init_with_transfers(struct spi_message *m,
912struct spi_transfer *xfers, unsigned int num_xfers)
913{
914 unsigned int i;
915
916 spi_message_init(m);
917 for (i = 0; i < num_xfers; ++i)
918 spi_message_add_tail(&xfers[i], m);
919}
920
David Brownell0c868462006-01-08 13:34:25 -0800921/* It's fine to embed message and transaction structures in other data
922 * structures so long as you don't free them while they're in use.
923 */
924
925static inline struct spi_message *spi_message_alloc(unsigned ntrans, gfp_t flags)
926{
927 struct spi_message *m;
928
929 m = kzalloc(sizeof(struct spi_message)
930 + ntrans * sizeof(struct spi_transfer),
931 flags);
932 if (m) {
Shubhrajyoti D8f536022012-02-27 19:29:05 +0530933 unsigned i;
Vitaly Wool8275c642006-01-08 13:34:28 -0800934 struct spi_transfer *t = (struct spi_transfer *)(m + 1);
935
Emiliano Ingrassiaed77d6b2017-03-28 09:49:29 +0200936 spi_message_init_no_memset(m);
Vitaly Wool8275c642006-01-08 13:34:28 -0800937 for (i = 0; i < ntrans; i++, t++)
938 spi_message_add_tail(t, m);
David Brownell0c868462006-01-08 13:34:25 -0800939 }
940 return m;
941}
942
943static inline void spi_message_free(struct spi_message *m)
944{
945 kfree(m);
946}
947
David Brownell7d077192009-06-17 16:26:03 -0700948extern int spi_setup(struct spi_device *spi);
David Brownell568d0692009-09-22 16:46:18 -0700949extern int spi_async(struct spi_device *spi, struct spi_message *message);
Ernst Schwabcf32b71e2010-06-28 17:49:29 -0700950extern int spi_async_locked(struct spi_device *spi,
951 struct spi_message *message);
Geert Uytterhoeven6c364062017-05-22 15:11:41 +0200952extern int spi_slave_abort(struct spi_device *spi);
David Brownell8ae12a02006-01-08 13:34:19 -0800953
Michal Suchanek4acad4a2015-12-02 10:38:21 +0000954static inline size_t
Heiner Kallweit5090cc6a2016-08-17 21:08:01 +0200955spi_max_message_size(struct spi_device *spi)
956{
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200957 struct spi_controller *ctlr = spi->controller;
958
959 if (!ctlr->max_message_size)
Heiner Kallweit5090cc6a2016-08-17 21:08:01 +0200960 return SIZE_MAX;
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200961 return ctlr->max_message_size(spi);
Heiner Kallweit5090cc6a2016-08-17 21:08:01 +0200962}
963
964static inline size_t
Michal Suchanek4acad4a2015-12-02 10:38:21 +0000965spi_max_transfer_size(struct spi_device *spi)
966{
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200967 struct spi_controller *ctlr = spi->controller;
Heiner Kallweit5090cc6a2016-08-17 21:08:01 +0200968 size_t tr_max = SIZE_MAX;
969 size_t msg_max = spi_max_message_size(spi);
970
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200971 if (ctlr->max_transfer_size)
972 tr_max = ctlr->max_transfer_size(spi);
Heiner Kallweit5090cc6a2016-08-17 21:08:01 +0200973
974 /* transfer size limit must not be greater than messsage size limit */
975 return min(tr_max, msg_max);
Michal Suchanek4acad4a2015-12-02 10:38:21 +0000976}
977
David Brownell8ae12a02006-01-08 13:34:19 -0800978/*---------------------------------------------------------------------------*/
979
Martin Sperl523baf5a2015-12-14 15:20:19 +0000980/* SPI transfer replacement methods which make use of spi_res */
981
Javier Martinez Canillasc76d9ae2016-03-10 15:01:13 -0300982struct spi_replaced_transfers;
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200983typedef void (*spi_replaced_release_t)(struct spi_controller *ctlr,
Javier Martinez Canillasc76d9ae2016-03-10 15:01:13 -0300984 struct spi_message *msg,
985 struct spi_replaced_transfers *res);
Martin Sperl523baf5a2015-12-14 15:20:19 +0000986/**
987 * struct spi_replaced_transfers - structure describing the spi_transfer
988 * replacements that have occurred
989 * so that they can get reverted
990 * @release: some extra release code to get executed prior to
991 * relasing this structure
992 * @extradata: pointer to some extra data if requested or NULL
993 * @replaced_transfers: transfers that have been replaced and which need
994 * to get restored
995 * @replaced_after: the transfer after which the @replaced_transfers
996 * are to get re-inserted
997 * @inserted: number of transfers inserted
998 * @inserted_transfers: array of spi_transfers of array-size @inserted,
999 * that have been replacing replaced_transfers
1000 *
1001 * note: that @extradata will point to @inserted_transfers[@inserted]
1002 * if some extra allocation is requested, so alignment will be the same
1003 * as for spi_transfers
1004 */
Martin Sperl523baf5a2015-12-14 15:20:19 +00001005struct spi_replaced_transfers {
1006 spi_replaced_release_t release;
1007 void *extradata;
1008 struct list_head replaced_transfers;
1009 struct list_head *replaced_after;
1010 size_t inserted;
1011 struct spi_transfer inserted_transfers[];
1012};
1013
1014extern struct spi_replaced_transfers *spi_replace_transfers(
1015 struct spi_message *msg,
1016 struct spi_transfer *xfer_first,
1017 size_t remove,
1018 size_t insert,
1019 spi_replaced_release_t release,
1020 size_t extradatasize,
1021 gfp_t gfp);
1022
1023/*---------------------------------------------------------------------------*/
1024
Martin Sperld9f12122015-12-14 15:20:20 +00001025/* SPI transfer transformation methods */
1026
Geert Uytterhoeven8caab752017-06-13 13:23:52 +02001027extern int spi_split_transfers_maxsize(struct spi_controller *ctlr,
Martin Sperld9f12122015-12-14 15:20:20 +00001028 struct spi_message *msg,
1029 size_t maxsize,
1030 gfp_t gfp);
1031
1032/*---------------------------------------------------------------------------*/
1033
David Brownell8ae12a02006-01-08 13:34:19 -08001034/* All these synchronous SPI transfer routines are utilities layered
1035 * over the core async transfer primitive. Here, "synchronous" means
1036 * they will sleep uninterruptibly until the async transfer completes.
1037 */
1038
1039extern int spi_sync(struct spi_device *spi, struct spi_message *message);
Ernst Schwabcf32b71e2010-06-28 17:49:29 -07001040extern int spi_sync_locked(struct spi_device *spi, struct spi_message *message);
Geert Uytterhoeven8caab752017-06-13 13:23:52 +02001041extern int spi_bus_lock(struct spi_controller *ctlr);
1042extern int spi_bus_unlock(struct spi_controller *ctlr);
David Brownell8ae12a02006-01-08 13:34:19 -08001043
1044/**
Lars-Peter Clausen6d9eecd2013-01-09 17:31:00 +00001045 * spi_sync_transfer - synchronous SPI data transfer
1046 * @spi: device with which data will be exchanged
1047 * @xfers: An array of spi_transfers
1048 * @num_xfers: Number of items in the xfer array
1049 * Context: can sleep
1050 *
1051 * Does a synchronous SPI data transfer of the given spi_transfer array.
1052 *
1053 * For more specific semantics see spi_sync().
1054 *
Javier Martinez Canillasa1fdeaa2015-10-22 18:59:22 +02001055 * Return: Return: zero on success, else a negative error code.
Lars-Peter Clausen6d9eecd2013-01-09 17:31:00 +00001056 */
1057static inline int
1058spi_sync_transfer(struct spi_device *spi, struct spi_transfer *xfers,
1059 unsigned int num_xfers)
1060{
1061 struct spi_message msg;
1062
1063 spi_message_init_with_transfers(&msg, xfers, num_xfers);
1064
1065 return spi_sync(spi, &msg);
1066}
1067
Geert Uytterhoeven323117a2016-09-13 15:38:25 +02001068/**
1069 * spi_write - SPI synchronous write
1070 * @spi: device to which data will be written
1071 * @buf: data buffer
1072 * @len: data buffer size
1073 * Context: can sleep
1074 *
1075 * This function writes the buffer @buf.
1076 * Callable only from contexts that can sleep.
1077 *
1078 * Return: zero on success, else a negative error code.
1079 */
1080static inline int
1081spi_write(struct spi_device *spi, const void *buf, size_t len)
1082{
1083 struct spi_transfer t = {
1084 .tx_buf = buf,
1085 .len = len,
1086 };
1087
1088 return spi_sync_transfer(spi, &t, 1);
1089}
1090
1091/**
1092 * spi_read - SPI synchronous read
1093 * @spi: device from which data will be read
1094 * @buf: data buffer
1095 * @len: data buffer size
1096 * Context: can sleep
1097 *
1098 * This function reads the buffer @buf.
1099 * Callable only from contexts that can sleep.
1100 *
1101 * Return: zero on success, else a negative error code.
1102 */
1103static inline int
1104spi_read(struct spi_device *spi, void *buf, size_t len)
1105{
1106 struct spi_transfer t = {
1107 .rx_buf = buf,
1108 .len = len,
1109 };
1110
1111 return spi_sync_transfer(spi, &t, 1);
1112}
1113
David Brownell0c868462006-01-08 13:34:25 -08001114/* this copies txbuf and rxbuf data; for small transfers only! */
David Brownell8ae12a02006-01-08 13:34:19 -08001115extern int spi_write_then_read(struct spi_device *spi,
Mark Brown0c4a1592011-05-11 00:09:30 +02001116 const void *txbuf, unsigned n_tx,
1117 void *rxbuf, unsigned n_rx);
David Brownell8ae12a02006-01-08 13:34:19 -08001118
1119/**
1120 * spi_w8r8 - SPI synchronous 8 bit write followed by 8 bit read
1121 * @spi: device with which data will be exchanged
1122 * @cmd: command to be written before data is read back
David Brownell33e34dc2007-05-08 00:32:21 -07001123 * Context: can sleep
David Brownell8ae12a02006-01-08 13:34:19 -08001124 *
Javier Martinez Canillasa1fdeaa2015-10-22 18:59:22 +02001125 * Callable only from contexts that can sleep.
1126 *
1127 * Return: the (unsigned) eight bit number returned by the
1128 * device, or else a negative error code.
David Brownell8ae12a02006-01-08 13:34:19 -08001129 */
1130static inline ssize_t spi_w8r8(struct spi_device *spi, u8 cmd)
1131{
1132 ssize_t status;
1133 u8 result;
1134
1135 status = spi_write_then_read(spi, &cmd, 1, &result, 1);
1136
1137 /* return negative errno or unsigned value */
1138 return (status < 0) ? status : result;
1139}
1140
1141/**
1142 * spi_w8r16 - SPI synchronous 8 bit write followed by 16 bit read
1143 * @spi: device with which data will be exchanged
1144 * @cmd: command to be written before data is read back
David Brownell33e34dc2007-05-08 00:32:21 -07001145 * Context: can sleep
David Brownell8ae12a02006-01-08 13:34:19 -08001146 *
David Brownell8ae12a02006-01-08 13:34:19 -08001147 * The number is returned in wire-order, which is at least sometimes
1148 * big-endian.
Javier Martinez Canillasa1fdeaa2015-10-22 18:59:22 +02001149 *
1150 * Callable only from contexts that can sleep.
1151 *
1152 * Return: the (unsigned) sixteen bit number returned by the
1153 * device, or else a negative error code.
David Brownell8ae12a02006-01-08 13:34:19 -08001154 */
1155static inline ssize_t spi_w8r16(struct spi_device *spi, u8 cmd)
1156{
1157 ssize_t status;
1158 u16 result;
1159
Geert Uytterhoeven269ccca2014-01-12 13:59:06 +01001160 status = spi_write_then_read(spi, &cmd, 1, &result, 2);
David Brownell8ae12a02006-01-08 13:34:19 -08001161
1162 /* return negative errno or unsigned value */
1163 return (status < 0) ? status : result;
1164}
1165
Lars-Peter Clausen05071aa2013-09-27 16:34:27 +02001166/**
1167 * spi_w8r16be - SPI synchronous 8 bit write followed by 16 bit big-endian read
1168 * @spi: device with which data will be exchanged
1169 * @cmd: command to be written before data is read back
1170 * Context: can sleep
1171 *
Lars-Peter Clausen05071aa2013-09-27 16:34:27 +02001172 * This function is similar to spi_w8r16, with the exception that it will
1173 * convert the read 16 bit data word from big-endian to native endianness.
1174 *
Javier Martinez Canillasa1fdeaa2015-10-22 18:59:22 +02001175 * Callable only from contexts that can sleep.
1176 *
1177 * Return: the (unsigned) sixteen bit number returned by the device in cpu
1178 * endianness, or else a negative error code.
Lars-Peter Clausen05071aa2013-09-27 16:34:27 +02001179 */
1180static inline ssize_t spi_w8r16be(struct spi_device *spi, u8 cmd)
1181
1182{
1183 ssize_t status;
1184 __be16 result;
1185
1186 status = spi_write_then_read(spi, &cmd, 1, &result, 2);
1187 if (status < 0)
1188 return status;
1189
1190 return be16_to_cpu(result);
1191}
1192
Vignesh R556351f2015-12-11 09:39:56 +05301193/**
1194 * struct spi_flash_read_message - flash specific information for
1195 * spi-masters that provide accelerated flash read interfaces
1196 * @buf: buffer to read data
1197 * @from: offset within the flash from where data is to be read
1198 * @len: length of data to be read
1199 * @retlen: actual length of data read
1200 * @read_opcode: read_opcode to be used to communicate with flash
1201 * @addr_width: number of address bytes
1202 * @dummy_bytes: number of dummy bytes
1203 * @opcode_nbits: number of lines to send opcode
1204 * @addr_nbits: number of lines to send address
1205 * @data_nbits: number of lines for data
Vignesh Rf4502dd2016-06-08 12:18:31 +05301206 * @rx_sg: Scatterlist for receive data read from flash
1207 * @cur_msg_mapped: message has been mapped for DMA
Vignesh R556351f2015-12-11 09:39:56 +05301208 */
1209struct spi_flash_read_message {
1210 void *buf;
1211 loff_t from;
1212 size_t len;
1213 size_t retlen;
1214 u8 read_opcode;
1215 u8 addr_width;
1216 u8 dummy_bytes;
1217 u8 opcode_nbits;
1218 u8 addr_nbits;
1219 u8 data_nbits;
Vignesh Rf4502dd2016-06-08 12:18:31 +05301220 struct sg_table rx_sg;
1221 bool cur_msg_mapped;
Vignesh R556351f2015-12-11 09:39:56 +05301222};
1223
1224/* SPI core interface for flash read support */
1225static inline bool spi_flash_read_supported(struct spi_device *spi)
1226{
Geert Uytterhoeven8caab752017-06-13 13:23:52 +02001227 return spi->controller->spi_flash_read &&
1228 (!spi->controller->flash_read_supported ||
1229 spi->controller->flash_read_supported(spi));
Vignesh R556351f2015-12-11 09:39:56 +05301230}
1231
1232int spi_flash_read(struct spi_device *spi,
1233 struct spi_flash_read_message *msg);
1234
David Brownell8ae12a02006-01-08 13:34:19 -08001235/*---------------------------------------------------------------------------*/
1236
1237/*
1238 * INTERFACE between board init code and SPI infrastructure.
1239 *
1240 * No SPI driver ever sees these SPI device table segments, but
1241 * it's how the SPI core (or adapters that get hotplugged) grows
1242 * the driver model tree.
1243 *
1244 * As a rule, SPI devices can't be probed. Instead, board init code
1245 * provides a table listing the devices which are present, with enough
1246 * information to bind and set up the device's driver. There's basic
1247 * support for nonstatic configurations too; enough to handle adding
1248 * parport adapters, or microcontrollers acting as USB-to-SPI bridges.
1249 */
1250
David Brownell26042882007-07-31 00:39:44 -07001251/**
1252 * struct spi_board_info - board-specific template for a SPI device
1253 * @modalias: Initializes spi_device.modalias; identifies the driver.
1254 * @platform_data: Initializes spi_device.platform_data; the particular
1255 * data stored there is driver-specific.
Dmitry Torokhov826cf172017-02-28 14:25:18 -08001256 * @properties: Additional device properties for the device.
David Brownell26042882007-07-31 00:39:44 -07001257 * @controller_data: Initializes spi_device.controller_data; some
1258 * controllers need hints about hardware setup, e.g. for DMA.
1259 * @irq: Initializes spi_device.irq; depends on how the board is wired.
1260 * @max_speed_hz: Initializes spi_device.max_speed_hz; based on limits
1261 * from the chip datasheet and board-specific signal quality issues.
Geert Uytterhoeven8caab752017-06-13 13:23:52 +02001262 * @bus_num: Identifies which spi_controller parents the spi_device; unused
David Brownell26042882007-07-31 00:39:44 -07001263 * by spi_new_device(), and otherwise depends on board wiring.
1264 * @chip_select: Initializes spi_device.chip_select; depends on how
1265 * the board is wired.
1266 * @mode: Initializes spi_device.mode; based on the chip datasheet, board
1267 * wiring (some devices support both 3WIRE and standard modes), and
1268 * possibly presence of an inverter in the chipselect path.
1269 *
1270 * When adding new SPI devices to the device tree, these structures serve
1271 * as a partial device template. They hold information which can't always
1272 * be determined by drivers. Information that probe() can establish (such
1273 * as the default transfer wordsize) is not included here.
1274 *
1275 * These structures are used in two places. Their primary role is to
1276 * be stored in tables of board-specific device descriptors, which are
1277 * declared early in board initialization and then used (much later) to
1278 * populate a controller's device tree after the that controller's driver
1279 * initializes. A secondary (and atypical) role is as a parameter to
1280 * spi_new_device() call, which happens after those controller drivers
1281 * are active in some dynamic board configuration models.
1282 */
David Brownell8ae12a02006-01-08 13:34:19 -08001283struct spi_board_info {
1284 /* the device name and module name are coupled, like platform_bus;
1285 * "modalias" is normally the driver name.
1286 *
1287 * platform_data goes to spi_device.dev.platform_data,
David Brownellb8852442006-01-08 13:34:23 -08001288 * controller_data goes to spi_device.controller_data,
Dmitry Torokhov826cf172017-02-28 14:25:18 -08001289 * device properties are copied and attached to spi_device,
David Brownell8ae12a02006-01-08 13:34:19 -08001290 * irq is copied too
1291 */
Anton Vorontsov75368bf2009-09-22 16:46:04 -07001292 char modalias[SPI_NAME_SIZE];
David Brownell8ae12a02006-01-08 13:34:19 -08001293 const void *platform_data;
Dmitry Torokhov826cf172017-02-28 14:25:18 -08001294 const struct property_entry *properties;
David Brownellb8852442006-01-08 13:34:23 -08001295 void *controller_data;
David Brownell8ae12a02006-01-08 13:34:19 -08001296 int irq;
1297
1298 /* slower signaling on noisy or low voltage boards */
1299 u32 max_speed_hz;
1300
1301
1302 /* bus_num is board specific and matches the bus_num of some
Geert Uytterhoeven8caab752017-06-13 13:23:52 +02001303 * spi_controller that will probably be registered later.
David Brownell8ae12a02006-01-08 13:34:19 -08001304 *
1305 * chip_select reflects how this chip is wired to that master;
1306 * it's less than num_chipselect.
1307 */
1308 u16 bus_num;
1309 u16 chip_select;
1310
David Brownell980a01c2006-06-28 07:47:15 -07001311 /* mode becomes spi_device.mode, and is essential for chips
1312 * where the default of SPI_CS_HIGH = 0 is wrong.
1313 */
wangyuhangf477b7f2013-08-11 18:15:17 +08001314 u16 mode;
David Brownell980a01c2006-06-28 07:47:15 -07001315
David Brownell8ae12a02006-01-08 13:34:19 -08001316 /* ... may need additional spi_device chip config data here.
1317 * avoid stuff protocol drivers can set; but include stuff
1318 * needed to behave without being bound to a driver:
David Brownell8ae12a02006-01-08 13:34:19 -08001319 * - quirks like clock rate mattering when not selected
1320 */
1321};
1322
1323#ifdef CONFIG_SPI
1324extern int
1325spi_register_board_info(struct spi_board_info const *info, unsigned n);
1326#else
1327/* board init code may ignore whether SPI is configured or not */
1328static inline int
1329spi_register_board_info(struct spi_board_info const *info, unsigned n)
1330 { return 0; }
1331#endif
1332
1333
1334/* If you're hotplugging an adapter with devices (parport, usb, etc)
David Brownell0c868462006-01-08 13:34:25 -08001335 * use spi_new_device() to describe each device. You can also call
1336 * spi_unregister_device() to start making that device vanish, but
Geert Uytterhoeven8caab752017-06-13 13:23:52 +02001337 * normally that would be handled by spi_unregister_controller().
Grant Likelydc87c982008-05-15 16:50:22 -06001338 *
1339 * You can also use spi_alloc_device() and spi_add_device() to use a two
1340 * stage registration sequence for each spi_device. This gives the caller
1341 * some more control over the spi_device structure before it is registered,
1342 * but requires that caller to initialize fields that would otherwise
1343 * be defined using the board info.
David Brownell8ae12a02006-01-08 13:34:19 -08001344 */
1345extern struct spi_device *
Geert Uytterhoeven8caab752017-06-13 13:23:52 +02001346spi_alloc_device(struct spi_controller *ctlr);
Grant Likelydc87c982008-05-15 16:50:22 -06001347
1348extern int
1349spi_add_device(struct spi_device *spi);
1350
1351extern struct spi_device *
Geert Uytterhoeven8caab752017-06-13 13:23:52 +02001352spi_new_device(struct spi_controller *, struct spi_board_info *);
David Brownell8ae12a02006-01-08 13:34:19 -08001353
Geert Uytterhoeven3b1884c2015-11-30 15:28:06 +01001354extern void spi_unregister_device(struct spi_device *spi);
David Brownell8ae12a02006-01-08 13:34:19 -08001355
Anton Vorontsov75368bf2009-09-22 16:46:04 -07001356extern const struct spi_device_id *
1357spi_get_device_id(const struct spi_device *sdev);
1358
Beniamino Galvanib6713582014-11-22 16:21:39 +01001359static inline bool
Geert Uytterhoeven8caab752017-06-13 13:23:52 +02001360spi_transfer_is_last(struct spi_controller *ctlr, struct spi_transfer *xfer)
Beniamino Galvanib6713582014-11-22 16:21:39 +01001361{
Geert Uytterhoeven8caab752017-06-13 13:23:52 +02001362 return list_is_last(&xfer->transfer_list, &ctlr->cur_msg->transfers);
Beniamino Galvanib6713582014-11-22 16:21:39 +01001363}
1364
Geert Uytterhoeven8caab752017-06-13 13:23:52 +02001365
1366/* Compatibility layer */
1367#define spi_master spi_controller
1368
1369#define SPI_MASTER_HALF_DUPLEX SPI_CONTROLLER_HALF_DUPLEX
1370#define SPI_MASTER_NO_RX SPI_CONTROLLER_NO_RX
1371#define SPI_MASTER_NO_TX SPI_CONTROLLER_NO_TX
1372#define SPI_MASTER_MUST_RX SPI_CONTROLLER_MUST_RX
1373#define SPI_MASTER_MUST_TX SPI_CONTROLLER_MUST_TX
1374
1375#define spi_master_get_devdata(_ctlr) spi_controller_get_devdata(_ctlr)
1376#define spi_master_set_devdata(_ctlr, _data) \
1377 spi_controller_set_devdata(_ctlr, _data)
1378#define spi_master_get(_ctlr) spi_controller_get(_ctlr)
1379#define spi_master_put(_ctlr) spi_controller_put(_ctlr)
1380#define spi_master_suspend(_ctlr) spi_controller_suspend(_ctlr)
1381#define spi_master_resume(_ctlr) spi_controller_resume(_ctlr)
1382
1383#define spi_register_master(_ctlr) spi_register_controller(_ctlr)
1384#define devm_spi_register_master(_dev, _ctlr) \
1385 devm_spi_register_controller(_dev, _ctlr)
1386#define spi_unregister_master(_ctlr) spi_unregister_controller(_ctlr)
1387
David Brownell8ae12a02006-01-08 13:34:19 -08001388#endif /* __LINUX_SPI_H */