blob: 662b336aa2e47e17d1dfea259903512168f38140 [file] [log] [blame]
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)
Jonas Bonnb7bb3672019-01-30 09:40:04 +0100125 * @word_delay_usecs: microsecond delay to be inserted between consecutive
126 * words of a transfer
David Brownell8ae12a02006-01-08 13:34:19 -0800127 *
Martin Sperleca2ebc2015-06-22 13:00:36 +0000128 * @statistics: statistics for the spi_device
129 *
David Brownell33e34dc2007-05-08 00:32:21 -0700130 * A @spi_device is used to interchange data between an SPI slave
David Brownell8ae12a02006-01-08 13:34:19 -0800131 * (usually a discrete chip) and CPU memory.
132 *
David Brownell33e34dc2007-05-08 00:32:21 -0700133 * In @dev, the platform_data is used to hold information about this
David Brownell8ae12a02006-01-08 13:34:19 -0800134 * device that's meaningful to the device's protocol driver, but not
135 * to its controller. One example might be an identifier for a chip
David Brownell33e34dc2007-05-08 00:32:21 -0700136 * variant with slightly different functionality; another might be
137 * information about how this particular board wires the chip's pins.
David Brownell8ae12a02006-01-08 13:34:19 -0800138 */
139struct spi_device {
140 struct device dev;
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200141 struct spi_controller *controller;
142 struct spi_controller *master; /* compatibility layer */
David Brownell8ae12a02006-01-08 13:34:19 -0800143 u32 max_speed_hz;
144 u8 chip_select;
Trent Piepho89c1f60742013-12-13 18:27:44 -0800145 u8 bits_per_word;
wangyuhangf477b7f2013-08-11 18:15:17 +0800146 u16 mode;
David Brownellb8852442006-01-08 13:34:23 -0800147#define SPI_CPHA 0x01 /* clock phase */
148#define SPI_CPOL 0x02 /* clock polarity */
David Brownell0c8684612006-01-08 13:34:25 -0800149#define SPI_MODE_0 (0|0) /* (original MicroWire) */
150#define SPI_MODE_1 (0|SPI_CPHA)
David Brownell8ae12a02006-01-08 13:34:19 -0800151#define SPI_MODE_2 (SPI_CPOL|0)
152#define SPI_MODE_3 (SPI_CPOL|SPI_CPHA)
David Brownellb8852442006-01-08 13:34:23 -0800153#define SPI_CS_HIGH 0x04 /* chipselect active high? */
David Brownellccf77cc2006-04-03 15:46:22 -0700154#define SPI_LSB_FIRST 0x08 /* per-word bits-on-wire */
David Brownellc06e6772007-07-17 04:04:03 -0700155#define SPI_3WIRE 0x10 /* SI/SO signals shared */
Anton Vorontsov4ef7af52007-07-31 00:38:43 -0700156#define SPI_LOOP 0x20 /* loopback mode */
David Brownellb55f6272009-06-30 11:41:26 -0700157#define SPI_NO_CS 0x40 /* 1 dev/bus, no chipselect */
158#define SPI_READY 0x80 /* slave pulls low to pause */
wangyuhangf477b7f2013-08-11 18:15:17 +0800159#define SPI_TX_DUAL 0x100 /* transmit with 2 wires */
160#define SPI_TX_QUAD 0x200 /* transmit with 4 wires */
161#define SPI_RX_DUAL 0x400 /* receive with 2 wires */
162#define SPI_RX_QUAD 0x800 /* receive with 4 wires */
Yogesh Narayan Gaur6b030612018-12-03 08:39:06 +0000163#define SPI_CS_WORD 0x1000 /* toggle cs after each word */
164#define SPI_TX_OCTAL 0x2000 /* transmit with 8 wires */
165#define SPI_RX_OCTAL 0x4000 /* receive with 8 wires */
Mark Brownae218f72018-12-04 17:31:49 +0000166#define SPI_3WIRE_HIZ 0x8000 /* high impedance turnaround */
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];
Trent Piepho50395632018-09-20 19:18:32 +0000171 const char *driver_override;
Linus Walleijf3186dd2019-01-07 16:51:50 +0100172 int cs_gpio; /* LEGACY: chip select gpio */
173 struct gpio_desc *cs_gpiod; /* chip select gpio desc */
Jonas Bonnb7bb3672019-01-30 09:40:04 +0100174 uint8_t word_delay_usecs; /* inter-word delay */
David Brownell8ae12a02006-01-08 13:34:19 -0800175
Martin Sperleca2ebc2015-06-22 13:00:36 +0000176 /* the statistics */
177 struct spi_statistics statistics;
178
David Brownell33e34dc2007-05-08 00:32:21 -0700179 /*
180 * likely need more hooks for more protocol options affecting how
181 * the controller talks to each chip, like:
182 * - memory packing (12 bit samples into low bits, others zeroed)
183 * - priority
David Brownell33e34dc2007-05-08 00:32:21 -0700184 * - chipselect delays
185 * - ...
186 */
David Brownell8ae12a02006-01-08 13:34:19 -0800187};
188
189static inline struct spi_device *to_spi_device(struct device *dev)
190{
David Brownellb8852442006-01-08 13:34:23 -0800191 return dev ? container_of(dev, struct spi_device, dev) : NULL;
David Brownell8ae12a02006-01-08 13:34:19 -0800192}
193
194/* most drivers won't need to care about device refcounting */
195static inline struct spi_device *spi_dev_get(struct spi_device *spi)
196{
197 return (spi && get_device(&spi->dev)) ? spi : NULL;
198}
199
200static inline void spi_dev_put(struct spi_device *spi)
201{
202 if (spi)
203 put_device(&spi->dev);
204}
205
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200206/* ctldata is for the bus_controller driver's runtime state */
David Brownell8ae12a02006-01-08 13:34:19 -0800207static inline void *spi_get_ctldata(struct spi_device *spi)
208{
209 return spi->controller_state;
210}
211
212static inline void spi_set_ctldata(struct spi_device *spi, void *state)
213{
214 spi->controller_state = state;
215}
216
Ben Dooks9b40ff42007-02-12 00:52:41 -0800217/* device driver data */
218
219static inline void spi_set_drvdata(struct spi_device *spi, void *data)
220{
221 dev_set_drvdata(&spi->dev, data);
222}
223
224static inline void *spi_get_drvdata(struct spi_device *spi)
225{
226 return dev_get_drvdata(&spi->dev);
227}
David Brownell8ae12a02006-01-08 13:34:19 -0800228
229struct spi_message;
Mark Brownb1589352013-10-05 11:50:40 +0100230struct spi_transfer;
David Brownellb8852442006-01-08 13:34:23 -0800231
David Brownell2604288f2007-07-31 00:39:44 -0700232/**
233 * struct spi_driver - Host side "protocol" driver
Anton Vorontsov75368bf2009-09-22 16:46:04 -0700234 * @id_table: List of SPI devices supported by this driver
David Brownell2604288f2007-07-31 00:39:44 -0700235 * @probe: Binds this driver to the spi device. Drivers can verify
236 * that the device is actually present, and may need to configure
237 * characteristics (such as bits_per_word) which weren't needed for
238 * the initial configuration done during system setup.
239 * @remove: Unbinds this driver from the spi device
240 * @shutdown: Standard shutdown callback used during system state
241 * transitions such as powerdown/halt and kexec
David Brownell2604288f2007-07-31 00:39:44 -0700242 * @driver: SPI device drivers should initialize the name and owner
243 * field of this structure.
244 *
245 * This represents the kind of device driver that uses SPI messages to
246 * interact with the hardware at the other end of a SPI link. It's called
247 * a "protocol" driver because it works through messages rather than talking
248 * directly to SPI hardware (which is what the underlying SPI controller
249 * driver does to pass those messages). These protocols are defined in the
250 * specification for the device(s) supported by the driver.
251 *
252 * As a rule, those device protocols represent the lowest level interface
253 * supported by a driver, and it will support upper level interfaces too.
254 * Examples of such upper levels include frameworks like MTD, networking,
255 * MMC, RTC, filesystem character device nodes, and hardware monitoring.
256 */
David Brownellb8852442006-01-08 13:34:23 -0800257struct spi_driver {
Anton Vorontsov75368bf2009-09-22 16:46:04 -0700258 const struct spi_device_id *id_table;
David Brownellb8852442006-01-08 13:34:23 -0800259 int (*probe)(struct spi_device *spi);
260 int (*remove)(struct spi_device *spi);
261 void (*shutdown)(struct spi_device *spi);
David Brownellb8852442006-01-08 13:34:23 -0800262 struct device_driver driver;
263};
264
265static inline struct spi_driver *to_spi_driver(struct device_driver *drv)
266{
267 return drv ? container_of(drv, struct spi_driver, driver) : NULL;
268}
269
Andrew F. Davisca5d2482015-10-23 08:59:10 -0500270extern int __spi_register_driver(struct module *owner, struct spi_driver *sdrv);
David Brownellb8852442006-01-08 13:34:23 -0800271
David Brownell33e34dc2007-05-08 00:32:21 -0700272/**
273 * spi_unregister_driver - reverse effect of spi_register_driver
274 * @sdrv: the driver to unregister
275 * Context: can sleep
276 */
David Brownellb8852442006-01-08 13:34:23 -0800277static inline void spi_unregister_driver(struct spi_driver *sdrv)
278{
Ben Dooksddc1e972007-02-12 00:52:43 -0800279 if (sdrv)
280 driver_unregister(&sdrv->driver);
David Brownellb8852442006-01-08 13:34:23 -0800281}
282
Andrew F. Davisca5d2482015-10-23 08:59:10 -0500283/* use a define to avoid include chaining to get THIS_MODULE */
284#define spi_register_driver(driver) \
285 __spi_register_driver(THIS_MODULE, driver)
286
Lars-Peter Clausen3acbb012011-11-16 10:13:37 +0100287/**
288 * module_spi_driver() - Helper macro for registering a SPI driver
289 * @__spi_driver: spi_driver struct
290 *
291 * Helper macro for SPI drivers which do not do anything special in module
292 * init/exit. This eliminates a lot of boilerplate. Each module may only
293 * use this macro once, and calling it replaces module_init() and module_exit()
294 */
295#define module_spi_driver(__spi_driver) \
296 module_driver(__spi_driver, spi_register_driver, \
297 spi_unregister_driver)
David Brownellb8852442006-01-08 13:34:23 -0800298
David Brownell8ae12a02006-01-08 13:34:19 -0800299/**
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200300 * struct spi_controller - interface to SPI master or slave controller
Tony Jones49dce682007-10-16 01:27:48 -0700301 * @dev: device interface to this driver
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200302 * @list: link with the global spi_controller list
David Brownell8ae12a02006-01-08 13:34:19 -0800303 * @bus_num: board-specific (and often SOC-specific) identifier for a
David Brownell747d8442006-04-02 10:33:37 -0800304 * given SPI controller.
David Brownellb8852442006-01-08 13:34:23 -0800305 * @num_chipselect: chipselects are used to distinguish individual
David Brownell747d8442006-04-02 10:33:37 -0800306 * SPI slaves, and are numbered from zero to num_chipselects.
307 * each slave has a chipselect signal, but it's common that not
308 * every chipselect is connected to a slave.
Mike Rapoportfd5e1912009-04-06 19:00:56 -0700309 * @dma_alignment: SPI controller constraint on DMA buffers alignment.
Randy Dunlapb73b2552009-09-22 16:46:00 -0700310 * @mode_bits: flags understood by this controller driver
Stephen Warren543bb252013-03-26 20:37:57 -0600311 * @bits_per_word_mask: A mask indicating which values of bits_per_word are
312 * supported by the driver. Bit n indicates that a bits_per_word n+1 is
Masanari Iidae2278672014-02-18 22:54:36 +0900313 * supported. If set, the SPI core will reject any transfer with an
Stephen Warren543bb252013-03-26 20:37:57 -0600314 * unsupported bits_per_word. If not set, this value is simply ignored,
315 * and it's up to the individual driver to perform any validation.
Mark Browna2fd4f92013-07-10 14:57:26 +0100316 * @min_speed_hz: Lowest supported transfer speed
317 * @max_speed_hz: Highest supported transfer speed
Randy Dunlapb73b2552009-09-22 16:46:00 -0700318 * @flags: other constraints relevant to this driver
Geert Uytterhoeven6c364062017-05-22 15:11:41 +0200319 * @slave: indicates that this is an SPI slave controller
Randy Dunlapee7683a2016-02-05 17:31:39 -0800320 * @max_transfer_size: function that returns the max transfer size for
321 * a &spi_device; may be %NULL, so the default %SIZE_MAX will be used.
Heiner Kallweit5090cc6a2016-08-17 21:08:01 +0200322 * @max_message_size: function that returns the max message size for
323 * a &spi_device; may be %NULL, so the default %SIZE_MAX will be used.
Mark Brownef4d96e2016-07-21 23:53:31 +0100324 * @io_mutex: mutex for physical bus access
Ernst Schwab5c79a5a2010-08-16 15:10:11 +0200325 * @bus_lock_spinlock: spinlock for SPI bus locking
Mark Brownef4d96e2016-07-21 23:53:31 +0100326 * @bus_lock_mutex: mutex for exclusion of multiple callers
Ernst Schwab5c79a5a2010-08-16 15:10:11 +0200327 * @bus_lock_flag: indicates that the SPI bus is locked for exclusive use
David Brownell8ae12a02006-01-08 13:34:19 -0800328 * @setup: updates the device mode and clocking records used by a
David Brownell80224562007-02-12 00:52:46 -0800329 * device's SPI controller; protocol code may call this. This
330 * must fail if an unrecognized or unsupported mode is requested.
David Brownell33e34dc2007-05-08 00:32:21 -0700331 * It's always safe to call this unless transfers are pending on
332 * the device whose settings are being modified.
David Brownell8ae12a02006-01-08 13:34:19 -0800333 * @transfer: adds a message to the controller's transfer queue.
334 * @cleanup: frees controller-specific state
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200335 * @can_dma: determine whether this controller supports DMA
336 * @queued: whether this controller is providing an internal message queue
Linus Walleijffbbdd212012-02-22 10:05:38 +0100337 * @kworker: thread struct for message pump
338 * @kworker_task: pointer to task for message pump kworker thread
339 * @pump_messages: work struct for scheduling work to the message pump
340 * @queue_lock: spinlock to syncronise access to message queue
341 * @queue: message queue
Mark Brown0461a412014-12-09 21:38:05 +0000342 * @idling: the device is entering idle state
Linus Walleijffbbdd212012-02-22 10:05:38 +0100343 * @cur_msg: the currently in-flight message
Mark Brown2841a5f2013-10-05 00:23:12 +0100344 * @cur_msg_prepared: spi_prepare_message was called for the currently
345 * in-flight message
Thierry Reding2c675682014-08-08 13:02:36 +0200346 * @cur_msg_mapped: message has been mapped for DMA
Masanari Iidae2278672014-02-18 22:54:36 +0900347 * @xfer_completion: used by core transfer_one_message()
Linus Walleijffbbdd212012-02-22 10:05:38 +0100348 * @busy: message pump is busy
349 * @running: message pump is running
350 * @rt: whether this queue is set to run as a realtime task
Mark Brown49834de2013-07-28 14:47:02 +0100351 * @auto_runtime_pm: the core should ensure a runtime PM reference is held
352 * while the hardware is prepared, using the parent
353 * device for the spidev
Mark Brown6ad45a22014-02-02 13:47:47 +0000354 * @max_dma_len: Maximum length of a DMA transfer for the device.
Linus Walleijffbbdd212012-02-22 10:05:38 +0100355 * @prepare_transfer_hardware: a message will soon arrive from the queue
356 * so the subsystem requests the driver to prepare the transfer hardware
357 * by issuing this call
358 * @transfer_one_message: the subsystem calls the driver to transfer a single
359 * message while queuing transfers that arrive in the meantime. When the
360 * driver is finished with this message, it must call
361 * spi_finalize_current_message() so the subsystem can issue the next
Baruch Siache9305332014-01-25 22:36:15 +0200362 * message
Randy Dunlapdbabe0d2012-04-17 17:03:50 -0700363 * @unprepare_transfer_hardware: there are currently no more messages on the
Linus Walleijffbbdd212012-02-22 10:05:38 +0100364 * queue so the subsystem notifies the driver that it may relax the
365 * hardware by issuing this call
Geert Uytterhoevenbd6857a2014-01-21 16:10:07 +0100366 * @set_cs: set the logic level of the chip select line. May be called
Mark Brownb1589352013-10-05 11:50:40 +0100367 * from interrupt context.
Mark Brown2841a5f2013-10-05 00:23:12 +0100368 * @prepare_message: set up the controller to transfer a single message,
369 * for example doing DMA mapping. Called from threaded
370 * context.
Geert Uytterhoeven05167122014-01-21 16:10:06 +0100371 * @transfer_one: transfer a single spi_transfer.
372 * - return 0 if the transfer is finished,
373 * - return 1 if the transfer is still in progress. When
374 * the driver is finished with this transfer it must
375 * call spi_finalize_current_transfer() so the subsystem
Baruch Siach6e5f5262014-01-25 22:36:13 +0200376 * can issue the next transfer. Note: transfer_one and
377 * transfer_one_message are mutually exclusive; when both
378 * are set, the generic subsystem does not call your
379 * transfer_one callback.
Geert Uytterhoevenff61eb42015-04-07 20:39:19 +0200380 * @handle_err: the subsystem calls the driver to handle an error that occurs
Andy Shevchenkob716c4f2015-02-27 17:34:15 +0200381 * in the generic implementation of transfer_one_message().
Boris Brezillonc36ff262018-04-26 18:18:14 +0200382 * @mem_ops: optimized/dedicated operations for interactions with SPI memory.
383 * This field is optional and should only be implemented if the
384 * controller has native support for memory like operations.
Mark Brown2841a5f2013-10-05 00:23:12 +0100385 * @unprepare_message: undo any work done by prepare_message().
Geert Uytterhoeven6c364062017-05-22 15:11:41 +0200386 * @slave_abort: abort the ongoing transfer request on an SPI slave controller
Linus Walleijf3186dd2019-01-07 16:51:50 +0100387 * @cs_gpios: LEGACY: array of GPIO descs to use as chip select lines; one per
388 * CS number. Any individual value may be -ENOENT for CS lines that
389 * are not GPIOs (driven by the SPI controller itself). Use the cs_gpiods
390 * in new drivers.
391 * @cs_gpiods: Array of GPIO descs to use as chip select lines; one per CS
392 * number. Any individual value may be NULL for CS lines that
Andreas Larsson095c3752013-01-29 15:53:41 +0100393 * are not GPIOs (driven by the SPI controller itself).
Linus Walleijf3186dd2019-01-07 16:51:50 +0100394 * @use_gpio_descriptors: Turns on the code in the SPI core to parse and grab
395 * GPIO descriptors rather than using global GPIO numbers grabbed by the
396 * driver. This will fill in @cs_gpiods and @cs_gpios should not be used,
397 * and SPI devices will have the cs_gpiod assigned rather than cs_gpio.
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200398 * @statistics: statistics for the spi_controller
Thierry Reding2c675682014-08-08 13:02:36 +0200399 * @dma_tx: DMA transmit channel
400 * @dma_rx: DMA receive channel
401 * @dummy_rx: dummy receive buffer for full-duplex devices
402 * @dummy_tx: dummy transmit buffer for full-duplex devices
Mika Westerberga0a90712016-02-08 17:14:28 +0200403 * @fw_translate_cs: If the boot firmware uses different numbering scheme
404 * what Linux expects, this optional hook can be used to translate
405 * between the two.
David Brownell8ae12a02006-01-08 13:34:19 -0800406 *
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200407 * Each SPI controller can communicate with one or more @spi_device
David Brownell8ae12a02006-01-08 13:34:19 -0800408 * children. These make a small bus, sharing MOSI, MISO and SCK signals
409 * but not chip select signals. Each device may be configured to use a
410 * different clock rate, since those shared signals are ignored unless
411 * the chip is selected.
412 *
413 * The driver for an SPI controller manages access to those devices through
David Brownell33e34dc2007-05-08 00:32:21 -0700414 * a queue of spi_message transactions, copying data between CPU memory and
415 * an SPI slave device. For each such message it queues, it calls the
David Brownell8ae12a02006-01-08 13:34:19 -0800416 * message's completion function when the transaction completes.
417 */
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200418struct spi_controller {
Tony Jones49dce682007-10-16 01:27:48 -0700419 struct device dev;
David Brownell8ae12a02006-01-08 13:34:19 -0800420
Feng Tang2b9603a2010-08-02 15:52:15 +0800421 struct list_head list;
422
David Brownella020ed72006-04-03 15:49:04 -0700423 /* other than negative (== assign one dynamically), bus_num is fully
David Brownell8ae12a02006-01-08 13:34:19 -0800424 * board-specific. usually that simplifies to being SOC-specific.
David Brownella020ed72006-04-03 15:49:04 -0700425 * example: one SOC has three SPI controllers, numbered 0..2,
David Brownell8ae12a02006-01-08 13:34:19 -0800426 * and one board's schematics might show it using SPI-2. software
427 * would normally use bus_num=2 for that controller.
428 */
David Brownella020ed72006-04-03 15:49:04 -0700429 s16 bus_num;
David Brownell8ae12a02006-01-08 13:34:19 -0800430
431 /* chipselects will be integral to many controllers; some others
432 * might use board-specific GPIOs.
433 */
434 u16 num_chipselect;
435
Mike Rapoportfd5e1912009-04-06 19:00:56 -0700436 /* some SPI controllers pose alignment requirements on DMAable
437 * buffers; let protocol drivers know about these requirements.
438 */
439 u16 dma_alignment;
440
David Brownelle7db06b2009-06-17 16:26:04 -0700441 /* spi_device.mode flags understood by this controller driver */
442 u16 mode_bits;
443
Stephen Warren543bb252013-03-26 20:37:57 -0600444 /* bitmask of supported bits_per_word for transfers */
445 u32 bits_per_word_mask;
Stephen Warren2922a8d2013-05-21 20:36:34 -0600446#define SPI_BPW_MASK(bits) BIT((bits) - 1)
Stephen Warrenb6aa23c2013-08-01 16:08:57 -0600447#define SPI_BIT_MASK(bits) (((bits) == 32) ? ~0U : (BIT(bits) - 1))
Stephen Warreneca89602013-05-30 09:59:40 -0600448#define SPI_BPW_RANGE_MASK(min, max) (SPI_BIT_MASK(max) - SPI_BIT_MASK(min - 1))
Stephen Warren543bb252013-03-26 20:37:57 -0600449
Mark Browna2fd4f92013-07-10 14:57:26 +0100450 /* limits on transfer speed */
451 u32 min_speed_hz;
452 u32 max_speed_hz;
453
David Brownell70d60272009-06-30 11:41:27 -0700454 /* other constraints relevant to this driver */
455 u16 flags;
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200456#define SPI_CONTROLLER_HALF_DUPLEX BIT(0) /* can't do full duplex */
457#define SPI_CONTROLLER_NO_RX BIT(1) /* can't do buffer read */
458#define SPI_CONTROLLER_NO_TX BIT(2) /* can't do buffer write */
459#define SPI_CONTROLLER_MUST_RX BIT(3) /* requires rx */
460#define SPI_CONTROLLER_MUST_TX BIT(4) /* requires tx */
461
462#define SPI_MASTER_GPIO_SS BIT(5) /* GPIO CS must select slave */
David Brownell70d60272009-06-30 11:41:27 -0700463
Geert Uytterhoeven6c364062017-05-22 15:11:41 +0200464 /* flag indicating this is an SPI slave controller */
465 bool slave;
466
Michal Suchanek4acad4a2015-12-02 10:38:21 +0000467 /*
Heiner Kallweit5090cc6a2016-08-17 21:08:01 +0200468 * on some hardware transfer / message size may be constrained
Michal Suchanek4acad4a2015-12-02 10:38:21 +0000469 * the limit may depend on device transfer settings
470 */
471 size_t (*max_transfer_size)(struct spi_device *spi);
Heiner Kallweit5090cc6a2016-08-17 21:08:01 +0200472 size_t (*max_message_size)(struct spi_device *spi);
Michal Suchanek4acad4a2015-12-02 10:38:21 +0000473
Mark Brownef4d96e2016-07-21 23:53:31 +0100474 /* I/O mutex */
475 struct mutex io_mutex;
476
Ernst Schwabcf32b71e2010-06-28 17:49:29 -0700477 /* lock and mutex for SPI bus locking */
478 spinlock_t bus_lock_spinlock;
479 struct mutex bus_lock_mutex;
480
481 /* flag indicating that the SPI bus is locked for exclusive use */
482 bool bus_lock_flag;
483
David Brownell6e538aa2009-04-21 12:24:49 -0700484 /* Setup mode and clock, etc (spi driver may call many times).
485 *
486 * IMPORTANT: this may be called when transfers to another
487 * device are active. DO NOT UPDATE SHARED REGISTERS in ways
488 * which could break those transfers.
489 */
David Brownell8ae12a02006-01-08 13:34:19 -0800490 int (*setup)(struct spi_device *spi);
491
492 /* bidirectional bulk transfers
493 *
494 * + The transfer() method may not sleep; its main role is
495 * just to add the message to the queue.
496 * + For now there's no remove-from-queue operation, or
497 * any other request management
498 * + To a given spi_device, message queueing is pure fifo
499 *
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200500 * + The controller's main job is to process its message queue,
501 * selecting a chip (for masters), then transferring data
David Brownell8ae12a02006-01-08 13:34:19 -0800502 * + If there are multiple spi_device children, the i/o queue
503 * arbitration algorithm is unspecified (round robin, fifo,
504 * priority, reservations, preemption, etc)
505 *
506 * + Chipselect stays active during the entire message
507 * (unless modified by spi_transfer.cs_change != 0).
508 * + The message transfers use clock and SPI mode parameters
509 * previously established by setup() for this device
510 */
511 int (*transfer)(struct spi_device *spi,
512 struct spi_message *mesg);
513
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200514 /* called on release() to free memory provided by spi_controller */
Hans-Peter Nilsson0ffa0282007-02-12 00:52:45 -0800515 void (*cleanup)(struct spi_device *spi);
Linus Walleijffbbdd212012-02-22 10:05:38 +0100516
517 /*
Mark Brown99adef32014-01-16 12:22:43 +0000518 * Used to enable core support for DMA handling, if can_dma()
519 * exists and returns true then the transfer will be mapped
520 * prior to transfer_one() being called. The driver should
521 * not modify or store xfer and dma_tx and dma_rx must be set
522 * while the device is prepared.
523 */
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200524 bool (*can_dma)(struct spi_controller *ctlr,
Mark Brown99adef32014-01-16 12:22:43 +0000525 struct spi_device *spi,
526 struct spi_transfer *xfer);
527
528 /*
Linus Walleijffbbdd212012-02-22 10:05:38 +0100529 * These hooks are for drivers that want to use the generic
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200530 * controller transfer queueing mechanism. If these are used, the
Linus Walleijffbbdd212012-02-22 10:05:38 +0100531 * transfer() function above must NOT be specified by the driver.
532 * Over time we expect SPI drivers to be phased over to this API.
533 */
534 bool queued;
535 struct kthread_worker kworker;
536 struct task_struct *kworker_task;
537 struct kthread_work pump_messages;
538 spinlock_t queue_lock;
539 struct list_head queue;
540 struct spi_message *cur_msg;
Mark Brown0461a412014-12-09 21:38:05 +0000541 bool idling;
Linus Walleijffbbdd212012-02-22 10:05:38 +0100542 bool busy;
543 bool running;
544 bool rt;
Mark Brown49834de2013-07-28 14:47:02 +0100545 bool auto_runtime_pm;
Mark Brown2841a5f2013-10-05 00:23:12 +0100546 bool cur_msg_prepared;
Mark Brown99adef32014-01-16 12:22:43 +0000547 bool cur_msg_mapped;
Mark Brownb1589352013-10-05 11:50:40 +0100548 struct completion xfer_completion;
Mark Brown6ad45a22014-02-02 13:47:47 +0000549 size_t max_dma_len;
Linus Walleijffbbdd212012-02-22 10:05:38 +0100550
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200551 int (*prepare_transfer_hardware)(struct spi_controller *ctlr);
552 int (*transfer_one_message)(struct spi_controller *ctlr,
Linus Walleijffbbdd212012-02-22 10:05:38 +0100553 struct spi_message *mesg);
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200554 int (*unprepare_transfer_hardware)(struct spi_controller *ctlr);
555 int (*prepare_message)(struct spi_controller *ctlr,
Mark Brown2841a5f2013-10-05 00:23:12 +0100556 struct spi_message *message);
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200557 int (*unprepare_message)(struct spi_controller *ctlr,
Mark Brown2841a5f2013-10-05 00:23:12 +0100558 struct spi_message *message);
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200559 int (*slave_abort)(struct spi_controller *ctlr);
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;
Linus Walleijf3186dd2019-01-07 16:51:50 +0100576 struct gpio_desc **cs_gpiods;
577 bool use_gpio_descriptors;
Mark Brown99adef32014-01-16 12:22:43 +0000578
Martin Sperleca2ebc2015-06-22 13:00:36 +0000579 /* statistics */
580 struct spi_statistics statistics;
581
Mark Brown99adef32014-01-16 12:22:43 +0000582 /* DMA channels for use with core dmaengine helpers */
583 struct dma_chan *dma_tx;
584 struct dma_chan *dma_rx;
Mark Brown3a2eba92014-01-28 20:17:03 +0000585
586 /* dummy data for full duplex devices */
587 void *dummy_rx;
588 void *dummy_tx;
Mika Westerberga0a90712016-02-08 17:14:28 +0200589
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200590 int (*fw_translate_cs)(struct spi_controller *ctlr, unsigned cs);
David Brownell8ae12a02006-01-08 13:34:19 -0800591};
592
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200593static inline void *spi_controller_get_devdata(struct spi_controller *ctlr)
David Brownell0c8684612006-01-08 13:34:25 -0800594{
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200595 return dev_get_drvdata(&ctlr->dev);
David Brownell0c8684612006-01-08 13:34:25 -0800596}
597
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200598static inline void spi_controller_set_devdata(struct spi_controller *ctlr,
599 void *data)
David Brownell0c8684612006-01-08 13:34:25 -0800600{
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200601 dev_set_drvdata(&ctlr->dev, data);
David Brownell0c8684612006-01-08 13:34:25 -0800602}
603
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200604static inline struct spi_controller *spi_controller_get(struct spi_controller *ctlr)
David Brownell0c8684612006-01-08 13:34:25 -0800605{
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200606 if (!ctlr || !get_device(&ctlr->dev))
David Brownell0c8684612006-01-08 13:34:25 -0800607 return NULL;
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200608 return ctlr;
David Brownell0c8684612006-01-08 13:34:25 -0800609}
610
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200611static inline void spi_controller_put(struct spi_controller *ctlr)
David Brownell0c8684612006-01-08 13:34:25 -0800612{
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200613 if (ctlr)
614 put_device(&ctlr->dev);
David Brownell0c8684612006-01-08 13:34:25 -0800615}
616
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200617static inline bool spi_controller_is_slave(struct spi_controller *ctlr)
Geert Uytterhoeven6c364062017-05-22 15:11:41 +0200618{
619 return IS_ENABLED(CONFIG_SPI_SLAVE) && ctlr->slave;
620}
621
Linus Walleijffbbdd212012-02-22 10:05:38 +0100622/* PM calls that need to be issued by the driver */
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200623extern int spi_controller_suspend(struct spi_controller *ctlr);
624extern int spi_controller_resume(struct spi_controller *ctlr);
Linus Walleijffbbdd212012-02-22 10:05:38 +0100625
626/* Calls the driver make to interact with the message queue */
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200627extern struct spi_message *spi_get_next_queued_message(struct spi_controller *ctlr);
628extern void spi_finalize_current_message(struct spi_controller *ctlr);
629extern void spi_finalize_current_transfer(struct spi_controller *ctlr);
David Brownell0c8684612006-01-08 13:34:25 -0800630
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200631/* the spi driver core manages memory for the spi_controller classdev */
632extern struct spi_controller *__spi_alloc_controller(struct device *host,
633 unsigned int size, bool slave);
Geert Uytterhoeven6c364062017-05-22 15:11:41 +0200634
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200635static inline struct spi_controller *spi_alloc_master(struct device *host,
636 unsigned int size)
Geert Uytterhoeven6c364062017-05-22 15:11:41 +0200637{
638 return __spi_alloc_controller(host, size, false);
639}
640
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200641static inline struct spi_controller *spi_alloc_slave(struct device *host,
642 unsigned int size)
Geert Uytterhoeven6c364062017-05-22 15:11:41 +0200643{
644 if (!IS_ENABLED(CONFIG_SPI_SLAVE))
645 return NULL;
646
647 return __spi_alloc_controller(host, size, true);
648}
David Brownell8ae12a02006-01-08 13:34:19 -0800649
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200650extern int spi_register_controller(struct spi_controller *ctlr);
651extern int devm_spi_register_controller(struct device *dev,
652 struct spi_controller *ctlr);
653extern void spi_unregister_controller(struct spi_controller *ctlr);
David Brownell8ae12a02006-01-08 13:34:19 -0800654
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200655extern struct spi_controller *spi_busnum_to_master(u16 busnum);
David Brownell8ae12a02006-01-08 13:34:19 -0800656
Martin Sperld780c372015-12-14 15:20:18 +0000657/*
658 * SPI resource management while processing a SPI message
659 */
660
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200661typedef void (*spi_res_release_t)(struct spi_controller *ctlr,
Martin Sperld6497812016-02-18 15:53:10 +0000662 struct spi_message *msg,
663 void *res);
664
Martin Sperld780c372015-12-14 15:20:18 +0000665/**
666 * struct spi_res - spi resource management structure
667 * @entry: list entry
668 * @release: release code called prior to freeing this resource
669 * @data: extra data allocated for the specific use-case
670 *
671 * this is based on ideas from devres, but focused on life-cycle
672 * management during spi_message processing
673 */
Martin Sperld780c372015-12-14 15:20:18 +0000674struct spi_res {
675 struct list_head entry;
676 spi_res_release_t release;
677 unsigned long long data[]; /* guarantee ull alignment */
678};
679
680extern void *spi_res_alloc(struct spi_device *spi,
681 spi_res_release_t release,
682 size_t size, gfp_t gfp);
683extern void spi_res_add(struct spi_message *message, void *res);
684extern void spi_res_free(void *res);
685
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200686extern void spi_res_release(struct spi_controller *ctlr,
Martin Sperld780c372015-12-14 15:20:18 +0000687 struct spi_message *message);
688
David Brownell8ae12a02006-01-08 13:34:19 -0800689/*---------------------------------------------------------------------------*/
690
691/*
692 * I/O INTERFACE between SPI controller and protocol drivers
693 *
694 * Protocol drivers use a queue of spi_messages, each transferring data
695 * between the controller and memory buffers.
696 *
697 * The spi_messages themselves consist of a series of read+write transfer
698 * segments. Those segments always read the same number of bits as they
699 * write; but one or the other is easily ignored by passing a null buffer
700 * pointer. (This is unlike most types of I/O API, because SPI hardware
701 * is full duplex.)
702 *
703 * NOTE: Allocation of spi_transfer and spi_message memory is entirely
704 * up to the protocol driver, which guarantees the integrity of both (as
705 * well as the data buffers) for as long as the message is queued.
706 */
707
708/**
709 * struct spi_transfer - a read/write buffer pair
Vitaly Wool8275c642006-01-08 13:34:28 -0800710 * @tx_buf: data to be written (dma-safe memory), or NULL
711 * @rx_buf: data to be read (dma-safe memory), or NULL
David Brownell33e34dc2007-05-08 00:32:21 -0700712 * @tx_dma: DMA address of tx_buf, if @spi_message.is_dma_mapped
713 * @rx_dma: DMA address of rx_buf, if @spi_message.is_dma_mapped
Masanari Iidae2278672014-02-18 22:54:36 +0900714 * @tx_nbits: number of bits used for writing. If 0 the default
wangyuhangf477b7f2013-08-11 18:15:17 +0800715 * (SPI_NBITS_SINGLE) is used.
716 * @rx_nbits: number of bits used for reading. If 0 the default
717 * (SPI_NBITS_SINGLE) is used.
David Brownell8ae12a02006-01-08 13:34:19 -0800718 * @len: size of rx and tx buffers (in bytes)
Frederik Schwarzer025dfda2008-10-16 19:02:37 +0200719 * @speed_hz: Select a speed other than the device default for this
David Brownell33e34dc2007-05-08 00:32:21 -0700720 * transfer. If 0 the default (from @spi_device) is used.
Frederik Schwarzer025dfda2008-10-16 19:02:37 +0200721 * @bits_per_word: select a bits_per_word other than the device default
David Brownell33e34dc2007-05-08 00:32:21 -0700722 * for this transfer. If 0 the default (from @spi_device) is used.
David Brownell8ae12a02006-01-08 13:34:19 -0800723 * @cs_change: affects chipselect after this transfer completes
724 * @delay_usecs: microseconds to delay after this transfer before
David Brownell747d8442006-04-02 10:33:37 -0800725 * (optionally) changing the chipselect status, then starting
David Brownell33e34dc2007-05-08 00:32:21 -0700726 * the next transfer or completing this @spi_message.
Jonas Bonnb7bb3672019-01-30 09:40:04 +0100727 * @word_delay_usecs: microseconds to inter word delay after each word size
728 * (set by bits_per_word) transmission.
Baolin Wangeeaceb82018-08-16 20:54:49 +0800729 * @word_delay: clock cycles to inter word delay after each word size
730 * (set by bits_per_word) transmission.
David Brownell33e34dc2007-05-08 00:32:21 -0700731 * @transfer_list: transfers are sequenced through @spi_message.transfers
Mark Brown6ad45a22014-02-02 13:47:47 +0000732 * @tx_sg: Scatterlist for transmit, currently not for client use
733 * @rx_sg: Scatterlist for receive, currently not for client use
David Brownell8ae12a02006-01-08 13:34:19 -0800734 *
735 * SPI transfers always write the same number of bytes as they read.
David Brownell33e34dc2007-05-08 00:32:21 -0700736 * Protocol drivers should always provide @rx_buf and/or @tx_buf.
David Brownell8ae12a02006-01-08 13:34:19 -0800737 * In some cases, they may also want to provide DMA addresses for
738 * the data being transferred; that may reduce overhead, when the
739 * underlying driver uses dma.
740 *
David Brownell4b1badf2006-12-29 16:48:39 -0800741 * If the transmit buffer is null, zeroes will be shifted out
David Brownell33e34dc2007-05-08 00:32:21 -0700742 * while filling @rx_buf. If the receive buffer is null, the data
Vitaly Wool8275c642006-01-08 13:34:28 -0800743 * shifted in will be discarded. Only "len" bytes shift out (or in).
744 * It's an error to try to shift out a partial word. (For example, by
745 * shifting out three bytes with word size of sixteen or twenty bits;
746 * the former uses two bytes per word, the latter uses four bytes.)
747 *
David Brownell80224562007-02-12 00:52:46 -0800748 * In-memory data values are always in native CPU byte order, translated
749 * from the wire byte order (big-endian except with SPI_LSB_FIRST). So
750 * for example when bits_per_word is sixteen, buffers are 2N bytes long
David Brownell33e34dc2007-05-08 00:32:21 -0700751 * (@len = 2N) and hold N sixteen bit words in CPU byte order.
David Brownell80224562007-02-12 00:52:46 -0800752 *
753 * When the word size of the SPI transfer is not a power-of-two multiple
754 * of eight bits, those in-memory words include extra bits. In-memory
755 * words are always seen by protocol drivers as right-justified, so the
756 * undefined (rx) or unused (tx) bits are always the most significant bits.
757 *
Vitaly Wool8275c642006-01-08 13:34:28 -0800758 * All SPI transfers start with the relevant chipselect active. Normally
759 * it stays selected until after the last transfer in a message. Drivers
David Brownell33e34dc2007-05-08 00:32:21 -0700760 * can affect the chipselect signal using cs_change.
David Brownell8ae12a02006-01-08 13:34:19 -0800761 *
762 * (i) If the transfer isn't the last one in the message, this flag is
763 * used to make the chipselect briefly go inactive in the middle of the
764 * message. Toggling chipselect in this way may be needed to terminate
765 * a chip command, letting a single spi_message perform all of group of
766 * chip transactions together.
767 *
768 * (ii) When the transfer is the last one in the message, the chip may
David Brownellf5a9c772007-06-16 10:16:08 -0700769 * stay selected until the next transfer. On multi-device SPI busses
770 * with nothing blocking messages going to other devices, this is just
771 * a performance hint; starting a message to another device deselects
772 * this one. But in other cases, this can be used to ensure correctness.
773 * Some devices need protocol transactions to be built from a series of
774 * spi_message submissions, where the content of one message is determined
775 * by the results of previous messages and where the whole transaction
776 * ends when the chipselect goes intactive.
David Brownell0c8684612006-01-08 13:34:25 -0800777 *
Masanari Iidae2278672014-02-18 22:54:36 +0900778 * When SPI can transfer in 1x,2x or 4x. It can get this transfer information
wangyuhangf477b7f2013-08-11 18:15:17 +0800779 * from device through @tx_nbits and @rx_nbits. In Bi-direction, these
780 * two should both be set. User can set transfer mode with SPI_NBITS_SINGLE(1x)
781 * SPI_NBITS_DUAL(2x) and SPI_NBITS_QUAD(4x) to support these three transfer.
782 *
David Brownell0c8684612006-01-08 13:34:25 -0800783 * The code that submits an spi_message (and its spi_transfers)
784 * to the lower layers is responsible for managing its memory.
785 * Zero-initialize every field you don't set up explicitly, to
Vitaly Wool8275c642006-01-08 13:34:28 -0800786 * insulate against future API updates. After you submit a message
787 * and its transfers, ignore them until its completion callback.
David Brownell8ae12a02006-01-08 13:34:19 -0800788 */
789struct spi_transfer {
790 /* it's ok if tx_buf == rx_buf (right?)
791 * for MicroWire, one buffer must be null
David Brownell0c8684612006-01-08 13:34:25 -0800792 * buffers must work with dma_*map_single() calls, unless
793 * spi_message.is_dma_mapped reports a pre-existing mapping
David Brownell8ae12a02006-01-08 13:34:19 -0800794 */
795 const void *tx_buf;
796 void *rx_buf;
797 unsigned len;
798
799 dma_addr_t tx_dma;
800 dma_addr_t rx_dma;
Mark Brown6ad45a22014-02-02 13:47:47 +0000801 struct sg_table tx_sg;
802 struct sg_table rx_sg;
David Brownell8ae12a02006-01-08 13:34:19 -0800803
804 unsigned cs_change:1;
Mark Brownd3fbd452014-01-10 17:09:53 +0000805 unsigned tx_nbits:3;
806 unsigned rx_nbits:3;
wangyuhangf477b7f2013-08-11 18:15:17 +0800807#define SPI_NBITS_SINGLE 0x01 /* 1bit transfer */
808#define SPI_NBITS_DUAL 0x02 /* 2bits transfer */
809#define SPI_NBITS_QUAD 0x04 /* 4bits transfer */
Imre Deak4cff33f2006-02-17 10:02:18 -0800810 u8 bits_per_word;
Jonas Bonnb7bb3672019-01-30 09:40:04 +0100811 u8 word_delay_usecs;
David Brownell8ae12a02006-01-08 13:34:19 -0800812 u16 delay_usecs;
Imre Deak4cff33f2006-02-17 10:02:18 -0800813 u32 speed_hz;
Baolin Wangeeaceb82018-08-16 20:54:49 +0800814 u16 word_delay;
Vitaly Wool8275c642006-01-08 13:34:28 -0800815
816 struct list_head transfer_list;
David Brownell8ae12a02006-01-08 13:34:19 -0800817};
818
819/**
820 * struct spi_message - one multi-segment SPI transaction
Vitaly Wool8275c642006-01-08 13:34:28 -0800821 * @transfers: list of transfer segments in this transaction
David Brownell8ae12a02006-01-08 13:34:19 -0800822 * @spi: SPI device to which the transaction is queued
823 * @is_dma_mapped: if true, the caller provided both dma and cpu virtual
824 * addresses for each transfer buffer
825 * @complete: called to report transaction completions
826 * @context: the argument to complete() when it's called
Thierry Reding2c675682014-08-08 13:02:36 +0200827 * @frame_length: the total number of bytes in the message
David Brownellb8852442006-01-08 13:34:23 -0800828 * @actual_length: the total number of bytes that were transferred in all
829 * successful segments
David Brownell8ae12a02006-01-08 13:34:19 -0800830 * @status: zero for success, else negative errno
831 * @queue: for use by whichever driver currently owns the message
832 * @state: for use by whichever driver currently owns the message
Martin Sperld780c372015-12-14 15:20:18 +0000833 * @resources: for resource management when the spi message is processed
David Brownell0c8684612006-01-08 13:34:25 -0800834 *
David Brownell33e34dc2007-05-08 00:32:21 -0700835 * A @spi_message is used to execute an atomic sequence of data transfers,
Vitaly Wool8275c642006-01-08 13:34:28 -0800836 * each represented by a struct spi_transfer. The sequence is "atomic"
837 * in the sense that no other spi_message may use that SPI bus until that
838 * sequence completes. On some systems, many such sequences can execute as
839 * as single programmed DMA transfer. On all systems, these messages are
840 * queued, and might complete after transactions to other devices. Messages
Marcin Bisc6331ba2015-03-01 13:49:32 +0100841 * sent to a given spi_device are always executed in FIFO order.
Vitaly Wool8275c642006-01-08 13:34:28 -0800842 *
David Brownell0c8684612006-01-08 13:34:25 -0800843 * The code that submits an spi_message (and its spi_transfers)
844 * to the lower layers is responsible for managing its memory.
845 * Zero-initialize every field you don't set up explicitly, to
Vitaly Wool8275c642006-01-08 13:34:28 -0800846 * insulate against future API updates. After you submit a message
847 * and its transfers, ignore them until its completion callback.
David Brownell8ae12a02006-01-08 13:34:19 -0800848 */
849struct spi_message {
David Brownell747d8442006-04-02 10:33:37 -0800850 struct list_head transfers;
David Brownell8ae12a02006-01-08 13:34:19 -0800851
852 struct spi_device *spi;
853
854 unsigned is_dma_mapped:1;
855
856 /* REVISIT: we might want a flag affecting the behavior of the
857 * last transfer ... allowing things like "read 16 bit length L"
858 * immediately followed by "read L bytes". Basically imposing
859 * a specific message scheduling algorithm.
860 *
861 * Some controller drivers (message-at-a-time queue processing)
862 * could provide that as their default scheduling algorithm. But
David Brownellb8852442006-01-08 13:34:23 -0800863 * others (with multi-message pipelines) could need a flag to
David Brownell8ae12a02006-01-08 13:34:19 -0800864 * tell them about such special cases.
865 */
866
867 /* completion is reported through a callback */
David Brownell747d8442006-04-02 10:33:37 -0800868 void (*complete)(void *context);
David Brownell8ae12a02006-01-08 13:34:19 -0800869 void *context;
Sourav Poddar078726c2013-07-18 15:31:25 +0530870 unsigned frame_length;
David Brownell8ae12a02006-01-08 13:34:19 -0800871 unsigned actual_length;
872 int status;
873
874 /* for optional use by whatever driver currently owns the
875 * spi_message ... between calls to spi_async and then later
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200876 * complete(), that's the spi_controller controller driver.
David Brownell8ae12a02006-01-08 13:34:19 -0800877 */
878 struct list_head queue;
879 void *state;
Martin Sperld780c372015-12-14 15:20:18 +0000880
881 /* list of spi_res reources when the spi message is processed */
882 struct list_head resources;
David Brownell8ae12a02006-01-08 13:34:19 -0800883};
884
Martin Sperl49ddedf2015-11-27 13:56:03 +0000885static inline void spi_message_init_no_memset(struct spi_message *m)
886{
887 INIT_LIST_HEAD(&m->transfers);
Martin Sperld780c372015-12-14 15:20:18 +0000888 INIT_LIST_HEAD(&m->resources);
Martin Sperl49ddedf2015-11-27 13:56:03 +0000889}
890
Vitaly Wool8275c642006-01-08 13:34:28 -0800891static inline void spi_message_init(struct spi_message *m)
892{
893 memset(m, 0, sizeof *m);
Martin Sperl49ddedf2015-11-27 13:56:03 +0000894 spi_message_init_no_memset(m);
Vitaly Wool8275c642006-01-08 13:34:28 -0800895}
896
897static inline void
898spi_message_add_tail(struct spi_transfer *t, struct spi_message *m)
899{
900 list_add_tail(&t->transfer_list, &m->transfers);
901}
902
903static inline void
904spi_transfer_del(struct spi_transfer *t)
905{
906 list_del(&t->transfer_list);
907}
908
Lars-Peter Clausen6d9eecd2013-01-09 17:31:00 +0000909/**
910 * spi_message_init_with_transfers - Initialize spi_message and append transfers
911 * @m: spi_message to be initialized
912 * @xfers: An array of spi transfers
913 * @num_xfers: Number of items in the xfer array
914 *
915 * This function initializes the given spi_message and adds each spi_transfer in
916 * the given array to the message.
917 */
918static inline void
919spi_message_init_with_transfers(struct spi_message *m,
920struct spi_transfer *xfers, unsigned int num_xfers)
921{
922 unsigned int i;
923
924 spi_message_init(m);
925 for (i = 0; i < num_xfers; ++i)
926 spi_message_add_tail(&xfers[i], m);
927}
928
David Brownell0c8684612006-01-08 13:34:25 -0800929/* It's fine to embed message and transaction structures in other data
930 * structures so long as you don't free them while they're in use.
931 */
932
933static inline struct spi_message *spi_message_alloc(unsigned ntrans, gfp_t flags)
934{
935 struct spi_message *m;
936
937 m = kzalloc(sizeof(struct spi_message)
938 + ntrans * sizeof(struct spi_transfer),
939 flags);
940 if (m) {
Shubhrajyoti D8f536022012-02-27 19:29:05 +0530941 unsigned i;
Vitaly Wool8275c642006-01-08 13:34:28 -0800942 struct spi_transfer *t = (struct spi_transfer *)(m + 1);
943
Emiliano Ingrassiaed77d6b2017-03-28 09:49:29 +0200944 spi_message_init_no_memset(m);
Vitaly Wool8275c642006-01-08 13:34:28 -0800945 for (i = 0; i < ntrans; i++, t++)
946 spi_message_add_tail(t, m);
David Brownell0c8684612006-01-08 13:34:25 -0800947 }
948 return m;
949}
950
951static inline void spi_message_free(struct spi_message *m)
952{
953 kfree(m);
954}
955
David Brownell7d077192009-06-17 16:26:03 -0700956extern int spi_setup(struct spi_device *spi);
David Brownell568d0692009-09-22 16:46:18 -0700957extern int spi_async(struct spi_device *spi, struct spi_message *message);
Ernst Schwabcf32b71e2010-06-28 17:49:29 -0700958extern int spi_async_locked(struct spi_device *spi,
959 struct spi_message *message);
Geert Uytterhoeven6c364062017-05-22 15:11:41 +0200960extern int spi_slave_abort(struct spi_device *spi);
David Brownell8ae12a02006-01-08 13:34:19 -0800961
Michal Suchanek4acad4a2015-12-02 10:38:21 +0000962static inline size_t
Heiner Kallweit5090cc6a2016-08-17 21:08:01 +0200963spi_max_message_size(struct spi_device *spi)
964{
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200965 struct spi_controller *ctlr = spi->controller;
966
967 if (!ctlr->max_message_size)
Heiner Kallweit5090cc6a2016-08-17 21:08:01 +0200968 return SIZE_MAX;
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200969 return ctlr->max_message_size(spi);
Heiner Kallweit5090cc6a2016-08-17 21:08:01 +0200970}
971
972static inline size_t
Michal Suchanek4acad4a2015-12-02 10:38:21 +0000973spi_max_transfer_size(struct spi_device *spi)
974{
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200975 struct spi_controller *ctlr = spi->controller;
Heiner Kallweit5090cc6a2016-08-17 21:08:01 +0200976 size_t tr_max = SIZE_MAX;
977 size_t msg_max = spi_max_message_size(spi);
978
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200979 if (ctlr->max_transfer_size)
980 tr_max = ctlr->max_transfer_size(spi);
Heiner Kallweit5090cc6a2016-08-17 21:08:01 +0200981
982 /* transfer size limit must not be greater than messsage size limit */
983 return min(tr_max, msg_max);
Michal Suchanek4acad4a2015-12-02 10:38:21 +0000984}
985
David Brownell8ae12a02006-01-08 13:34:19 -0800986/*---------------------------------------------------------------------------*/
987
Martin Sperl523baf5a2015-12-14 15:20:19 +0000988/* SPI transfer replacement methods which make use of spi_res */
989
Javier Martinez Canillasc76d9ae2016-03-10 15:01:13 -0300990struct spi_replaced_transfers;
Geert Uytterhoeven8caab752017-06-13 13:23:52 +0200991typedef void (*spi_replaced_release_t)(struct spi_controller *ctlr,
Javier Martinez Canillasc76d9ae2016-03-10 15:01:13 -0300992 struct spi_message *msg,
993 struct spi_replaced_transfers *res);
Martin Sperl523baf5a2015-12-14 15:20:19 +0000994/**
995 * struct spi_replaced_transfers - structure describing the spi_transfer
996 * replacements that have occurred
997 * so that they can get reverted
998 * @release: some extra release code to get executed prior to
999 * relasing this structure
1000 * @extradata: pointer to some extra data if requested or NULL
1001 * @replaced_transfers: transfers that have been replaced and which need
1002 * to get restored
1003 * @replaced_after: the transfer after which the @replaced_transfers
1004 * are to get re-inserted
1005 * @inserted: number of transfers inserted
1006 * @inserted_transfers: array of spi_transfers of array-size @inserted,
1007 * that have been replacing replaced_transfers
1008 *
1009 * note: that @extradata will point to @inserted_transfers[@inserted]
1010 * if some extra allocation is requested, so alignment will be the same
1011 * as for spi_transfers
1012 */
Martin Sperl523baf5a2015-12-14 15:20:19 +00001013struct spi_replaced_transfers {
1014 spi_replaced_release_t release;
1015 void *extradata;
1016 struct list_head replaced_transfers;
1017 struct list_head *replaced_after;
1018 size_t inserted;
1019 struct spi_transfer inserted_transfers[];
1020};
1021
1022extern struct spi_replaced_transfers *spi_replace_transfers(
1023 struct spi_message *msg,
1024 struct spi_transfer *xfer_first,
1025 size_t remove,
1026 size_t insert,
1027 spi_replaced_release_t release,
1028 size_t extradatasize,
1029 gfp_t gfp);
1030
1031/*---------------------------------------------------------------------------*/
1032
Martin Sperld9f12122015-12-14 15:20:20 +00001033/* SPI transfer transformation methods */
1034
Geert Uytterhoeven8caab752017-06-13 13:23:52 +02001035extern int spi_split_transfers_maxsize(struct spi_controller *ctlr,
Martin Sperld9f12122015-12-14 15:20:20 +00001036 struct spi_message *msg,
1037 size_t maxsize,
1038 gfp_t gfp);
1039
1040/*---------------------------------------------------------------------------*/
1041
David Brownell8ae12a02006-01-08 13:34:19 -08001042/* All these synchronous SPI transfer routines are utilities layered
1043 * over the core async transfer primitive. Here, "synchronous" means
1044 * they will sleep uninterruptibly until the async transfer completes.
1045 */
1046
1047extern int spi_sync(struct spi_device *spi, struct spi_message *message);
Ernst Schwabcf32b71e2010-06-28 17:49:29 -07001048extern int spi_sync_locked(struct spi_device *spi, struct spi_message *message);
Geert Uytterhoeven8caab752017-06-13 13:23:52 +02001049extern int spi_bus_lock(struct spi_controller *ctlr);
1050extern int spi_bus_unlock(struct spi_controller *ctlr);
David Brownell8ae12a02006-01-08 13:34:19 -08001051
1052/**
Lars-Peter Clausen6d9eecd2013-01-09 17:31:00 +00001053 * spi_sync_transfer - synchronous SPI data transfer
1054 * @spi: device with which data will be exchanged
1055 * @xfers: An array of spi_transfers
1056 * @num_xfers: Number of items in the xfer array
1057 * Context: can sleep
1058 *
1059 * Does a synchronous SPI data transfer of the given spi_transfer array.
1060 *
1061 * For more specific semantics see spi_sync().
1062 *
Javier Martinez Canillasa1fdeaa2015-10-22 18:59:22 +02001063 * Return: Return: zero on success, else a negative error code.
Lars-Peter Clausen6d9eecd2013-01-09 17:31:00 +00001064 */
1065static inline int
1066spi_sync_transfer(struct spi_device *spi, struct spi_transfer *xfers,
1067 unsigned int num_xfers)
1068{
1069 struct spi_message msg;
1070
1071 spi_message_init_with_transfers(&msg, xfers, num_xfers);
1072
1073 return spi_sync(spi, &msg);
1074}
1075
Geert Uytterhoeven323117a2016-09-13 15:38:25 +02001076/**
1077 * spi_write - SPI synchronous write
1078 * @spi: device to which data will be written
1079 * @buf: data buffer
1080 * @len: data buffer size
1081 * Context: can sleep
1082 *
1083 * This function writes the buffer @buf.
1084 * Callable only from contexts that can sleep.
1085 *
1086 * Return: zero on success, else a negative error code.
1087 */
1088static inline int
1089spi_write(struct spi_device *spi, const void *buf, size_t len)
1090{
1091 struct spi_transfer t = {
1092 .tx_buf = buf,
1093 .len = len,
1094 };
1095
1096 return spi_sync_transfer(spi, &t, 1);
1097}
1098
1099/**
1100 * spi_read - SPI synchronous read
1101 * @spi: device from which data will be read
1102 * @buf: data buffer
1103 * @len: data buffer size
1104 * Context: can sleep
1105 *
1106 * This function reads the buffer @buf.
1107 * Callable only from contexts that can sleep.
1108 *
1109 * Return: zero on success, else a negative error code.
1110 */
1111static inline int
1112spi_read(struct spi_device *spi, void *buf, size_t len)
1113{
1114 struct spi_transfer t = {
1115 .rx_buf = buf,
1116 .len = len,
1117 };
1118
1119 return spi_sync_transfer(spi, &t, 1);
1120}
1121
David Brownell0c8684612006-01-08 13:34:25 -08001122/* this copies txbuf and rxbuf data; for small transfers only! */
David Brownell8ae12a02006-01-08 13:34:19 -08001123extern int spi_write_then_read(struct spi_device *spi,
Mark Brown0c4a1592011-05-11 00:09:30 +02001124 const void *txbuf, unsigned n_tx,
1125 void *rxbuf, unsigned n_rx);
David Brownell8ae12a02006-01-08 13:34:19 -08001126
1127/**
1128 * spi_w8r8 - SPI synchronous 8 bit write followed by 8 bit read
1129 * @spi: device with which data will be exchanged
1130 * @cmd: command to be written before data is read back
David Brownell33e34dc2007-05-08 00:32:21 -07001131 * Context: can sleep
David Brownell8ae12a02006-01-08 13:34:19 -08001132 *
Javier Martinez Canillasa1fdeaa2015-10-22 18:59:22 +02001133 * Callable only from contexts that can sleep.
1134 *
1135 * Return: the (unsigned) eight bit number returned by the
1136 * device, or else a negative error code.
David Brownell8ae12a02006-01-08 13:34:19 -08001137 */
1138static inline ssize_t spi_w8r8(struct spi_device *spi, u8 cmd)
1139{
1140 ssize_t status;
1141 u8 result;
1142
1143 status = spi_write_then_read(spi, &cmd, 1, &result, 1);
1144
1145 /* return negative errno or unsigned value */
1146 return (status < 0) ? status : result;
1147}
1148
1149/**
1150 * spi_w8r16 - SPI synchronous 8 bit write followed by 16 bit read
1151 * @spi: device with which data will be exchanged
1152 * @cmd: command to be written before data is read back
David Brownell33e34dc2007-05-08 00:32:21 -07001153 * Context: can sleep
David Brownell8ae12a02006-01-08 13:34:19 -08001154 *
David Brownell8ae12a02006-01-08 13:34:19 -08001155 * The number is returned in wire-order, which is at least sometimes
1156 * big-endian.
Javier Martinez Canillasa1fdeaa2015-10-22 18:59:22 +02001157 *
1158 * Callable only from contexts that can sleep.
1159 *
1160 * Return: the (unsigned) sixteen bit number returned by the
1161 * device, or else a negative error code.
David Brownell8ae12a02006-01-08 13:34:19 -08001162 */
1163static inline ssize_t spi_w8r16(struct spi_device *spi, u8 cmd)
1164{
1165 ssize_t status;
1166 u16 result;
1167
Geert Uytterhoeven269ccca2014-01-12 13:59:06 +01001168 status = spi_write_then_read(spi, &cmd, 1, &result, 2);
David Brownell8ae12a02006-01-08 13:34:19 -08001169
1170 /* return negative errno or unsigned value */
1171 return (status < 0) ? status : result;
1172}
1173
Lars-Peter Clausen05071aa2013-09-27 16:34:27 +02001174/**
1175 * spi_w8r16be - SPI synchronous 8 bit write followed by 16 bit big-endian read
1176 * @spi: device with which data will be exchanged
1177 * @cmd: command to be written before data is read back
1178 * Context: can sleep
1179 *
Lars-Peter Clausen05071aa2013-09-27 16:34:27 +02001180 * This function is similar to spi_w8r16, with the exception that it will
1181 * convert the read 16 bit data word from big-endian to native endianness.
1182 *
Javier Martinez Canillasa1fdeaa2015-10-22 18:59:22 +02001183 * Callable only from contexts that can sleep.
1184 *
1185 * Return: the (unsigned) sixteen bit number returned by the device in cpu
1186 * endianness, or else a negative error code.
Lars-Peter Clausen05071aa2013-09-27 16:34:27 +02001187 */
1188static inline ssize_t spi_w8r16be(struct spi_device *spi, u8 cmd)
1189
1190{
1191 ssize_t status;
1192 __be16 result;
1193
1194 status = spi_write_then_read(spi, &cmd, 1, &result, 2);
1195 if (status < 0)
1196 return status;
1197
1198 return be16_to_cpu(result);
1199}
1200
David Brownell8ae12a02006-01-08 13:34:19 -08001201/*---------------------------------------------------------------------------*/
1202
1203/*
1204 * INTERFACE between board init code and SPI infrastructure.
1205 *
1206 * No SPI driver ever sees these SPI device table segments, but
1207 * it's how the SPI core (or adapters that get hotplugged) grows
1208 * the driver model tree.
1209 *
1210 * As a rule, SPI devices can't be probed. Instead, board init code
1211 * provides a table listing the devices which are present, with enough
1212 * information to bind and set up the device's driver. There's basic
1213 * support for nonstatic configurations too; enough to handle adding
1214 * parport adapters, or microcontrollers acting as USB-to-SPI bridges.
1215 */
1216
David Brownell2604288f2007-07-31 00:39:44 -07001217/**
1218 * struct spi_board_info - board-specific template for a SPI device
1219 * @modalias: Initializes spi_device.modalias; identifies the driver.
1220 * @platform_data: Initializes spi_device.platform_data; the particular
1221 * data stored there is driver-specific.
Dmitry Torokhov826cf172017-02-28 14:25:18 -08001222 * @properties: Additional device properties for the device.
David Brownell2604288f2007-07-31 00:39:44 -07001223 * @controller_data: Initializes spi_device.controller_data; some
1224 * controllers need hints about hardware setup, e.g. for DMA.
1225 * @irq: Initializes spi_device.irq; depends on how the board is wired.
1226 * @max_speed_hz: Initializes spi_device.max_speed_hz; based on limits
1227 * from the chip datasheet and board-specific signal quality issues.
Geert Uytterhoeven8caab752017-06-13 13:23:52 +02001228 * @bus_num: Identifies which spi_controller parents the spi_device; unused
David Brownell2604288f2007-07-31 00:39:44 -07001229 * by spi_new_device(), and otherwise depends on board wiring.
1230 * @chip_select: Initializes spi_device.chip_select; depends on how
1231 * the board is wired.
1232 * @mode: Initializes spi_device.mode; based on the chip datasheet, board
1233 * wiring (some devices support both 3WIRE and standard modes), and
1234 * possibly presence of an inverter in the chipselect path.
1235 *
1236 * When adding new SPI devices to the device tree, these structures serve
1237 * as a partial device template. They hold information which can't always
1238 * be determined by drivers. Information that probe() can establish (such
1239 * as the default transfer wordsize) is not included here.
1240 *
1241 * These structures are used in two places. Their primary role is to
1242 * be stored in tables of board-specific device descriptors, which are
1243 * declared early in board initialization and then used (much later) to
1244 * populate a controller's device tree after the that controller's driver
1245 * initializes. A secondary (and atypical) role is as a parameter to
1246 * spi_new_device() call, which happens after those controller drivers
1247 * are active in some dynamic board configuration models.
1248 */
David Brownell8ae12a02006-01-08 13:34:19 -08001249struct spi_board_info {
1250 /* the device name and module name are coupled, like platform_bus;
1251 * "modalias" is normally the driver name.
1252 *
1253 * platform_data goes to spi_device.dev.platform_data,
David Brownellb8852442006-01-08 13:34:23 -08001254 * controller_data goes to spi_device.controller_data,
Dmitry Torokhov826cf172017-02-28 14:25:18 -08001255 * device properties are copied and attached to spi_device,
David Brownell8ae12a02006-01-08 13:34:19 -08001256 * irq is copied too
1257 */
Anton Vorontsov75368bf2009-09-22 16:46:04 -07001258 char modalias[SPI_NAME_SIZE];
David Brownell8ae12a02006-01-08 13:34:19 -08001259 const void *platform_data;
Dmitry Torokhov826cf172017-02-28 14:25:18 -08001260 const struct property_entry *properties;
David Brownellb8852442006-01-08 13:34:23 -08001261 void *controller_data;
David Brownell8ae12a02006-01-08 13:34:19 -08001262 int irq;
1263
1264 /* slower signaling on noisy or low voltage boards */
1265 u32 max_speed_hz;
1266
1267
1268 /* bus_num is board specific and matches the bus_num of some
Geert Uytterhoeven8caab752017-06-13 13:23:52 +02001269 * spi_controller that will probably be registered later.
David Brownell8ae12a02006-01-08 13:34:19 -08001270 *
1271 * chip_select reflects how this chip is wired to that master;
1272 * it's less than num_chipselect.
1273 */
1274 u16 bus_num;
1275 u16 chip_select;
1276
David Brownell980a01c2006-06-28 07:47:15 -07001277 /* mode becomes spi_device.mode, and is essential for chips
1278 * where the default of SPI_CS_HIGH = 0 is wrong.
1279 */
wangyuhangf477b7f2013-08-11 18:15:17 +08001280 u16 mode;
David Brownell980a01c2006-06-28 07:47:15 -07001281
David Brownell8ae12a02006-01-08 13:34:19 -08001282 /* ... may need additional spi_device chip config data here.
1283 * avoid stuff protocol drivers can set; but include stuff
1284 * needed to behave without being bound to a driver:
David Brownell8ae12a02006-01-08 13:34:19 -08001285 * - quirks like clock rate mattering when not selected
1286 */
1287};
1288
1289#ifdef CONFIG_SPI
1290extern int
1291spi_register_board_info(struct spi_board_info const *info, unsigned n);
1292#else
1293/* board init code may ignore whether SPI is configured or not */
1294static inline int
1295spi_register_board_info(struct spi_board_info const *info, unsigned n)
1296 { return 0; }
1297#endif
1298
David Brownell8ae12a02006-01-08 13:34:19 -08001299/* If you're hotplugging an adapter with devices (parport, usb, etc)
David Brownell0c8684612006-01-08 13:34:25 -08001300 * use spi_new_device() to describe each device. You can also call
1301 * spi_unregister_device() to start making that device vanish, but
Geert Uytterhoeven8caab752017-06-13 13:23:52 +02001302 * normally that would be handled by spi_unregister_controller().
Grant Likelydc87c982008-05-15 16:50:22 -06001303 *
1304 * You can also use spi_alloc_device() and spi_add_device() to use a two
1305 * stage registration sequence for each spi_device. This gives the caller
1306 * some more control over the spi_device structure before it is registered,
1307 * but requires that caller to initialize fields that would otherwise
1308 * be defined using the board info.
David Brownell8ae12a02006-01-08 13:34:19 -08001309 */
1310extern struct spi_device *
Geert Uytterhoeven8caab752017-06-13 13:23:52 +02001311spi_alloc_device(struct spi_controller *ctlr);
Grant Likelydc87c982008-05-15 16:50:22 -06001312
1313extern int
1314spi_add_device(struct spi_device *spi);
1315
1316extern struct spi_device *
Geert Uytterhoeven8caab752017-06-13 13:23:52 +02001317spi_new_device(struct spi_controller *, struct spi_board_info *);
David Brownell8ae12a02006-01-08 13:34:19 -08001318
Geert Uytterhoeven3b1884c2015-11-30 15:28:06 +01001319extern void spi_unregister_device(struct spi_device *spi);
David Brownell8ae12a02006-01-08 13:34:19 -08001320
Anton Vorontsov75368bf2009-09-22 16:46:04 -07001321extern const struct spi_device_id *
1322spi_get_device_id(const struct spi_device *sdev);
1323
Beniamino Galvanib6713582014-11-22 16:21:39 +01001324static inline bool
Geert Uytterhoeven8caab752017-06-13 13:23:52 +02001325spi_transfer_is_last(struct spi_controller *ctlr, struct spi_transfer *xfer)
Beniamino Galvanib6713582014-11-22 16:21:39 +01001326{
Geert Uytterhoeven8caab752017-06-13 13:23:52 +02001327 return list_is_last(&xfer->transfer_list, &ctlr->cur_msg->transfers);
Beniamino Galvanib6713582014-11-22 16:21:39 +01001328}
1329
Marco Felsch5f143af2018-09-25 11:42:29 +02001330/* OF support code */
1331#if IS_ENABLED(CONFIG_OF)
1332
1333/* must call put_device() when done with returned spi_device device */
1334extern struct spi_device *
1335of_find_spi_device_by_node(struct device_node *node);
1336
1337#else
1338
1339static inline struct spi_device *
1340of_find_spi_device_by_node(struct device_node *node)
1341{
1342 return NULL;
1343}
1344
1345#endif /* IS_ENABLED(CONFIG_OF) */
Geert Uytterhoeven8caab752017-06-13 13:23:52 +02001346
1347/* Compatibility layer */
1348#define spi_master spi_controller
1349
1350#define SPI_MASTER_HALF_DUPLEX SPI_CONTROLLER_HALF_DUPLEX
1351#define SPI_MASTER_NO_RX SPI_CONTROLLER_NO_RX
1352#define SPI_MASTER_NO_TX SPI_CONTROLLER_NO_TX
1353#define SPI_MASTER_MUST_RX SPI_CONTROLLER_MUST_RX
1354#define SPI_MASTER_MUST_TX SPI_CONTROLLER_MUST_TX
1355
1356#define spi_master_get_devdata(_ctlr) spi_controller_get_devdata(_ctlr)
1357#define spi_master_set_devdata(_ctlr, _data) \
1358 spi_controller_set_devdata(_ctlr, _data)
1359#define spi_master_get(_ctlr) spi_controller_get(_ctlr)
1360#define spi_master_put(_ctlr) spi_controller_put(_ctlr)
1361#define spi_master_suspend(_ctlr) spi_controller_suspend(_ctlr)
1362#define spi_master_resume(_ctlr) spi_controller_resume(_ctlr)
1363
1364#define spi_register_master(_ctlr) spi_register_controller(_ctlr)
1365#define devm_spi_register_master(_dev, _ctlr) \
1366 devm_spi_register_controller(_dev, _ctlr)
1367#define spi_unregister_master(_ctlr) spi_unregister_controller(_ctlr)
1368
David Brownell8ae12a02006-01-08 13:34:19 -08001369#endif /* __LINUX_SPI_H */