1 /* SPDX-License-Identifier: GPL-2.0+ */
2 /*
3 * Common SPI Interface: Controller-specific definitions
4 *
5 * (C) Copyright 2001
6 * Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com.
7 */
8
9 #ifndef _SPI_H_
10 #define _SPI_H_
11
12 /* SPI mode flags */
13 #define SPI_CPHA BIT(0) /* clock phase */
14 #define SPI_CPOL BIT(1) /* clock polarity */
15 #define SPI_MODE_0 (0|0) /* (original MicroWire) */
16 #define SPI_MODE_1 (0|SPI_CPHA)
17 #define SPI_MODE_2 (SPI_CPOL|0)
18 #define SPI_MODE_3 (SPI_CPOL|SPI_CPHA)
19 #define SPI_CS_HIGH BIT(2) /* CS active high */
20 #define SPI_LSB_FIRST BIT(3) /* per-word bits-on-wire */
21 #define SPI_3WIRE BIT(4) /* SI/SO signals shared */
22 #define SPI_LOOP BIT(5) /* loopback mode */
23 #define SPI_SLAVE BIT(6) /* slave mode */
24 #define SPI_PREAMBLE BIT(7) /* Skip preamble bytes */
25 #define SPI_TX_BYTE BIT(8) /* transmit with 1 wire byte */
26 #define SPI_TX_DUAL BIT(9) /* transmit with 2 wires */
27 #define SPI_TX_QUAD BIT(10) /* transmit with 4 wires */
28 #define SPI_RX_SLOW BIT(11) /* receive with 1 wire slow */
29 #define SPI_RX_DUAL BIT(12) /* receive with 2 wires */
30 #define SPI_RX_QUAD BIT(13) /* receive with 4 wires */
31
32 /* Header byte that marks the start of the message */
33 #define SPI_PREAMBLE_END_BYTE 0xec
34
35 #define SPI_DEFAULT_WORDLEN 8
36
37 #ifdef CONFIG_DM_SPI
38 /* TODO(sjg@chromium.org): Remove this and use max_hz from struct spi_slave */
39 struct dm_spi_bus {
40 uint max_hz;
41 };
42
43 /**
44 * struct dm_spi_platdata - platform data for all SPI slaves
45 *
46 * This describes a SPI slave, a child device of the SPI bus. To obtain this
47 * struct from a spi_slave, use dev_get_parent_platdata(dev) or
48 * dev_get_parent_platdata(slave->dev).
49 *
50 * This data is immuatable. Each time the device is probed, @max_hz and @mode
51 * will be copied to struct spi_slave.
52 *
53 * @cs: Chip select number (0..n-1)
54 * @max_hz: Maximum bus speed that this slave can tolerate
55 * @mode: SPI mode to use for this device (see SPI mode flags)
56 */
57 struct dm_spi_slave_platdata {
58 unsigned int cs;
59 uint max_hz;
60 uint mode;
61 };
62
63 #endif /* CONFIG_DM_SPI */
64
65 /**
66 * struct spi_slave - Representation of a SPI slave
67 *
68 * For driver model this is the per-child data used by the SPI bus. It can
69 * be accessed using dev_get_parent_priv() on the slave device. The SPI uclass
70 * sets uip per_child_auto_alloc_size to sizeof(struct spi_slave), and the
71 * driver should not override it. Two platform data fields (max_hz and mode)
72 * are copied into this structure to provide an initial value. This allows
73 * them to be changed, since we should never change platform data in drivers.
74 *
75 * If not using driver model, drivers are expected to extend this with
76 * controller-specific data.
77 *
78 * @dev: SPI slave device
79 * @max_hz: Maximum speed for this slave
80 * @speed: Current bus speed. This is 0 until the bus is first
81 * claimed.
82 * @bus: ID of the bus that the slave is attached to. For
83 * driver model this is the sequence number of the SPI
84 * bus (bus->seq) so does not need to be stored
85 * @cs: ID of the chip select connected to the slave.
86 * @mode: SPI mode to use for this slave (see SPI mode flags)
87 * @wordlen: Size of SPI word in number of bits
88 * @max_read_size: If non-zero, the maximum number of bytes which can
89 * be read at once.
90 * @max_write_size: If non-zero, the maximum number of bytes which can
91 * be written at once.
92 * @memory_map: Address of read-only SPI flash access.
93 * @flags: Indication of SPI flags.
94 */
95 struct spi_slave {
96 #ifdef CONFIG_DM_SPI
97 struct udevice *dev; /* struct spi_slave is dev->parentdata */
98 uint max_hz;
99 uint speed;
100 #else
101 unsigned int bus;
102 unsigned int cs;
103 #endif
104 uint mode;
105 unsigned int wordlen;
106 unsigned int max_read_size;
107 unsigned int max_write_size;
108 void *memory_map;
109
110 u8 flags;
111 #define SPI_XFER_BEGIN BIT(0) /* Assert CS before transfer */
112 #define SPI_XFER_END BIT(1) /* Deassert CS after transfer */
113 #define SPI_XFER_ONCE (SPI_XFER_BEGIN | SPI_XFER_END)
114 #define SPI_XFER_MMAP BIT(2) /* Memory Mapped start */
115 #define SPI_XFER_MMAP_END BIT(3) /* Memory Mapped End */
116 };
117
118 /**
119 * Initialization, must be called once on start up.
120 *
121 * TODO: I don't think we really need this.
122 */
123 void spi_init(void);
124
125 /**
126 * spi_do_alloc_slave - Allocate a new SPI slave (internal)
127 *
128 * Allocate and zero all fields in the spi slave, and set the bus/chip
129 * select. Use the helper macro spi_alloc_slave() to call this.
130 *
131 * @offset: Offset of struct spi_slave within slave structure.
132 * @size: Size of slave structure.
133 * @bus: Bus ID of the slave chip.
134 * @cs: Chip select ID of the slave chip on the specified bus.
135 */
136 void *spi_do_alloc_slave(int offset, int size, unsigned int bus,
137 unsigned int cs);
138
139 /**
140 * spi_alloc_slave - Allocate a new SPI slave
141 *
142 * Allocate and zero all fields in the spi slave, and set the bus/chip
143 * select.
144 *
145 * @_struct: Name of structure to allocate (e.g. struct tegra_spi).
146 * This structure must contain a member 'struct spi_slave *slave'.
147 * @bus: Bus ID of the slave chip.
148 * @cs: Chip select ID of the slave chip on the specified bus.
149 */
150 #define spi_alloc_slave(_struct, bus, cs) \
151 spi_do_alloc_slave(offsetof(_struct, slave), \
152 sizeof(_struct), bus, cs)
153
154 /**
155 * spi_alloc_slave_base - Allocate a new SPI slave with no private data
156 *
157 * Allocate and zero all fields in the spi slave, and set the bus/chip
158 * select.
159 *
160 * @bus: Bus ID of the slave chip.
161 * @cs: Chip select ID of the slave chip on the specified bus.
162 */
163 #define spi_alloc_slave_base(bus, cs) \
164 spi_do_alloc_slave(0, sizeof(struct spi_slave), bus, cs)
165
166 /**
167 * Set up communications parameters for a SPI slave.
168 *
169 * This must be called once for each slave. Note that this function
170 * usually doesn't touch any actual hardware, it only initializes the
171 * contents of spi_slave so that the hardware can be easily
172 * initialized later.
173 *
174 * @bus: Bus ID of the slave chip.
175 * @cs: Chip select ID of the slave chip on the specified bus.
176 * @max_hz: Maximum SCK rate in Hz.
177 * @mode: Clock polarity, clock phase and other parameters.
178 *
179 * Returns: A spi_slave reference that can be used in subsequent SPI
180 * calls, or NULL if one or more of the parameters are not supported.
181 */
182 struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
183 unsigned int max_hz, unsigned int mode);
184
185 /**
186 * Free any memory associated with a SPI slave.
187 *
188 * @slave: The SPI slave
189 */
190 void spi_free_slave(struct spi_slave *slave);
191
192 /**
193 * Claim the bus and prepare it for communication with a given slave.
194 *
195 * This must be called before doing any transfers with a SPI slave. It
196 * will enable and initialize any SPI hardware as necessary, and make
197 * sure that the SCK line is in the correct idle state. It is not
198 * allowed to claim the same bus for several slaves without releasing
199 * the bus in between.
200 *
201 * @slave: The SPI slave
202 *
203 * Returns: 0 if the bus was claimed successfully, or a negative value
204 * if it wasn't.
205 */
206 int spi_claim_bus(struct spi_slave *slave);
207
208 /**
209 * Release the SPI bus
210 *
211 * This must be called once for every call to spi_claim_bus() after
212 * all transfers have finished. It may disable any SPI hardware as
213 * appropriate.
214 *
215 * @slave: The SPI slave
216 */
217 void spi_release_bus(struct spi_slave *slave);
218
219 /**
220 * Set the word length for SPI transactions
221 *
222 * Set the word length (number of bits per word) for SPI transactions.
223 *
224 * @slave: The SPI slave
225 * @wordlen: The number of bits in a word
226 *
227 * Returns: 0 on success, -1 on failure.
228 */
229 int spi_set_wordlen(struct spi_slave *slave, unsigned int wordlen);
230
231 /**
232 * SPI transfer
233 *
234 * This writes "bitlen" bits out the SPI MOSI port and simultaneously clocks
235 * "bitlen" bits in the SPI MISO port. That's just the way SPI works.
236 *
237 * The source of the outgoing bits is the "dout" parameter and the
238 * destination of the input bits is the "din" parameter. Note that "dout"
239 * and "din" can point to the same memory location, in which case the
240 * input data overwrites the output data (since both are buffered by
241 * temporary variables, this is OK).
242 *
243 * spi_xfer() interface:
244 * @slave: The SPI slave which will be sending/receiving the data.
245 * @bitlen: How many bits to write and read.
246 * @dout: Pointer to a string of bits to send out. The bits are
247 * held in a byte array and are sent MSB first.
248 * @din: Pointer to a string of bits that will be filled in.
249 * @flags: A bitwise combination of SPI_XFER_* flags.
250 *
251 * Returns: 0 on success, not 0 on failure
252 */
253 int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
254 void *din, unsigned long flags);
255
256 /* Copy memory mapped data */
257 void spi_flash_copy_mmap(void *data, void *offset, size_t len);
258
259 /**
260 * Determine if a SPI chipselect is valid.
261 * This function is provided by the board if the low-level SPI driver
262 * needs it to determine if a given chipselect is actually valid.
263 *
264 * Returns: 1 if bus:cs identifies a valid chip on this board, 0
265 * otherwise.
266 */
267 int spi_cs_is_valid(unsigned int bus, unsigned int cs);
268
269 #ifndef CONFIG_DM_SPI
270 /**
271 * Activate a SPI chipselect.
272 * This function is provided by the board code when using a driver
273 * that can't control its chipselects automatically (e.g.
274 * common/soft_spi.c). When called, it should activate the chip select
275 * to the device identified by "slave".
276 */
277 void spi_cs_activate(struct spi_slave *slave);
278
279 /**
280 * Deactivate a SPI chipselect.
281 * This function is provided by the board code when using a driver
282 * that can't control its chipselects automatically (e.g.
283 * common/soft_spi.c). When called, it should deactivate the chip
284 * select to the device identified by "slave".
285 */
286 void spi_cs_deactivate(struct spi_slave *slave);
287
288 /**
289 * Set transfer speed.
290 * This sets a new speed to be applied for next spi_xfer().
291 * @slave: The SPI slave
292 * @hz: The transfer speed
293 */
294 void spi_set_speed(struct spi_slave *slave, uint hz);
295 #endif
296
297 /**
298 * Write 8 bits, then read 8 bits.
299 * @slave: The SPI slave we're communicating with
300 * @byte: Byte to be written
301 *
302 * Returns: The value that was read, or a negative value on error.
303 *
304 * TODO: This function probably shouldn't be inlined.
305 */
spi_w8r8(struct spi_slave * slave,unsigned char byte)306 static inline int spi_w8r8(struct spi_slave *slave, unsigned char byte)
307 {
308 unsigned char dout[2];
309 unsigned char din[2];
310 int ret;
311
312 dout[0] = byte;
313 dout[1] = 0;
314
315 ret = spi_xfer(slave, 16, dout, din, SPI_XFER_BEGIN | SPI_XFER_END);
316 return ret < 0 ? ret : din[1];
317 }
318
319 #ifdef CONFIG_DM_SPI
320
321 /**
322 * struct spi_cs_info - Information about a bus chip select
323 *
324 * @dev: Connected device, or NULL if none
325 */
326 struct spi_cs_info {
327 struct udevice *dev;
328 };
329
330 /**
331 * struct struct dm_spi_ops - Driver model SPI operations
332 *
333 * The uclass interface is implemented by all SPI devices which use
334 * driver model.
335 */
336 struct dm_spi_ops {
337 /**
338 * Claim the bus and prepare it for communication.
339 *
340 * The device provided is the slave device. It's parent controller
341 * will be used to provide the communication.
342 *
343 * This must be called before doing any transfers with a SPI slave. It
344 * will enable and initialize any SPI hardware as necessary, and make
345 * sure that the SCK line is in the correct idle state. It is not
346 * allowed to claim the same bus for several slaves without releasing
347 * the bus in between.
348 *
349 * @dev: The SPI slave
350 *
351 * Returns: 0 if the bus was claimed successfully, or a negative value
352 * if it wasn't.
353 */
354 int (*claim_bus)(struct udevice *dev);
355
356 /**
357 * Release the SPI bus
358 *
359 * This must be called once for every call to spi_claim_bus() after
360 * all transfers have finished. It may disable any SPI hardware as
361 * appropriate.
362 *
363 * @dev: The SPI slave
364 */
365 int (*release_bus)(struct udevice *dev);
366
367 /**
368 * Set the word length for SPI transactions
369 *
370 * Set the word length (number of bits per word) for SPI transactions.
371 *
372 * @bus: The SPI slave
373 * @wordlen: The number of bits in a word
374 *
375 * Returns: 0 on success, -ve on failure.
376 */
377 int (*set_wordlen)(struct udevice *dev, unsigned int wordlen);
378
379 /**
380 * SPI transfer
381 *
382 * This writes "bitlen" bits out the SPI MOSI port and simultaneously
383 * clocks "bitlen" bits in the SPI MISO port. That's just the way SPI
384 * works.
385 *
386 * The source of the outgoing bits is the "dout" parameter and the
387 * destination of the input bits is the "din" parameter. Note that
388 * "dout" and "din" can point to the same memory location, in which
389 * case the input data overwrites the output data (since both are
390 * buffered by temporary variables, this is OK).
391 *
392 * spi_xfer() interface:
393 * @dev: The slave device to communicate with
394 * @bitlen: How many bits to write and read.
395 * @dout: Pointer to a string of bits to send out. The bits are
396 * held in a byte array and are sent MSB first.
397 * @din: Pointer to a string of bits that will be filled in.
398 * @flags: A bitwise combination of SPI_XFER_* flags.
399 *
400 * Returns: 0 on success, not -1 on failure
401 */
402 int (*xfer)(struct udevice *dev, unsigned int bitlen, const void *dout,
403 void *din, unsigned long flags);
404
405 /**
406 * Set transfer speed.
407 * This sets a new speed to be applied for next spi_xfer().
408 * @bus: The SPI bus
409 * @hz: The transfer speed
410 * @return 0 if OK, -ve on error
411 */
412 int (*set_speed)(struct udevice *bus, uint hz);
413
414 /**
415 * Set the SPI mode/flags
416 *
417 * It is unclear if we want to set speed and mode together instead
418 * of separately.
419 *
420 * @bus: The SPI bus
421 * @mode: Requested SPI mode (SPI_... flags)
422 * @return 0 if OK, -ve on error
423 */
424 int (*set_mode)(struct udevice *bus, uint mode);
425
426 /**
427 * Get information on a chip select
428 *
429 * This is only called when the SPI uclass does not know about a
430 * chip select, i.e. it has no attached device. It gives the driver
431 * a chance to allow activity on that chip select even so.
432 *
433 * @bus: The SPI bus
434 * @cs: The chip select (0..n-1)
435 * @info: Returns information about the chip select, if valid.
436 * On entry info->dev is NULL
437 * @return 0 if OK (and @info is set up), -ENODEV if the chip select
438 * is invalid, other -ve value on error
439 */
440 int (*cs_info)(struct udevice *bus, uint cs, struct spi_cs_info *info);
441 };
442
443 struct dm_spi_emul_ops {
444 /**
445 * SPI transfer
446 *
447 * This writes "bitlen" bits out the SPI MOSI port and simultaneously
448 * clocks "bitlen" bits in the SPI MISO port. That's just the way SPI
449 * works. Here the device is a slave.
450 *
451 * The source of the outgoing bits is the "dout" parameter and the
452 * destination of the input bits is the "din" parameter. Note that
453 * "dout" and "din" can point to the same memory location, in which
454 * case the input data overwrites the output data (since both are
455 * buffered by temporary variables, this is OK).
456 *
457 * spi_xfer() interface:
458 * @slave: The SPI slave which will be sending/receiving the data.
459 * @bitlen: How many bits to write and read.
460 * @dout: Pointer to a string of bits sent to the device. The
461 * bits are held in a byte array and are sent MSB first.
462 * @din: Pointer to a string of bits that will be sent back to
463 * the master.
464 * @flags: A bitwise combination of SPI_XFER_* flags.
465 *
466 * Returns: 0 on success, not -1 on failure
467 */
468 int (*xfer)(struct udevice *slave, unsigned int bitlen,
469 const void *dout, void *din, unsigned long flags);
470 };
471
472 /**
473 * spi_find_bus_and_cs() - Find bus and slave devices by number
474 *
475 * Given a bus number and chip select, this finds the corresponding bus
476 * device and slave device. Neither device is activated by this function,
477 * although they may have been activated previously.
478 *
479 * @busnum: SPI bus number
480 * @cs: Chip select to look for
481 * @busp: Returns bus device
482 * @devp: Return slave device
483 * @return 0 if found, -ENODEV on error
484 */
485 int spi_find_bus_and_cs(int busnum, int cs, struct udevice **busp,
486 struct udevice **devp);
487
488 /**
489 * spi_get_bus_and_cs() - Find and activate bus and slave devices by number
490 *
491 * Given a bus number and chip select, this finds the corresponding bus
492 * device and slave device.
493 *
494 * If no such slave exists, and drv_name is not NULL, then a new slave device
495 * is automatically bound on this chip select.
496 *
497 * Ths new slave device is probed ready for use with the given speed and mode.
498 *
499 * @busnum: SPI bus number
500 * @cs: Chip select to look for
501 * @speed: SPI speed to use for this slave
502 * @mode: SPI mode to use for this slave
503 * @drv_name: Name of driver to attach to this chip select
504 * @dev_name: Name of the new device thus created
505 * @busp: Returns bus device
506 * @devp: Return slave device
507 * @return 0 if found, -ve on error
508 */
509 int spi_get_bus_and_cs(int busnum, int cs, int speed, int mode,
510 const char *drv_name, const char *dev_name,
511 struct udevice **busp, struct spi_slave **devp);
512
513 /**
514 * spi_chip_select() - Get the chip select for a slave
515 *
516 * @return the chip select this slave is attached to
517 */
518 int spi_chip_select(struct udevice *slave);
519
520 /**
521 * spi_find_chip_select() - Find the slave attached to chip select
522 *
523 * @bus: SPI bus to search
524 * @cs: Chip select to look for
525 * @devp: Returns the slave device if found
526 * @return 0 if found, -ENODEV on error
527 */
528 int spi_find_chip_select(struct udevice *bus, int cs, struct udevice **devp);
529
530 /**
531 * spi_slave_ofdata_to_platdata() - decode standard SPI platform data
532 *
533 * This decodes the speed and mode for a slave from a device tree node
534 *
535 * @blob: Device tree blob
536 * @node: Node offset to read from
537 * @plat: Place to put the decoded information
538 */
539 int spi_slave_ofdata_to_platdata(struct udevice *dev,
540 struct dm_spi_slave_platdata *plat);
541
542 /**
543 * spi_cs_info() - Check information on a chip select
544 *
545 * This checks a particular chip select on a bus to see if it has a device
546 * attached, or is even valid.
547 *
548 * @bus: The SPI bus
549 * @cs: The chip select (0..n-1)
550 * @info: Returns information about the chip select, if valid
551 * @return 0 if OK (and @info is set up), -ENODEV if the chip select
552 * is invalid, other -ve value on error
553 */
554 int spi_cs_info(struct udevice *bus, uint cs, struct spi_cs_info *info);
555
556 struct sandbox_state;
557
558 /**
559 * sandbox_spi_get_emul() - get an emulator for a SPI slave
560 *
561 * This provides a way to attach an emulated SPI device to a particular SPI
562 * slave, so that xfer() operations on the slave will be handled by the
563 * emulator. If a emulator already exists on that chip select it is returned.
564 * Otherwise one is created.
565 *
566 * @state: Sandbox state
567 * @bus: SPI bus requesting the emulator
568 * @slave: SPI slave device requesting the emulator
569 * @emuip: Returns pointer to emulator
570 * @return 0 if OK, -ve on error
571 */
572 int sandbox_spi_get_emul(struct sandbox_state *state,
573 struct udevice *bus, struct udevice *slave,
574 struct udevice **emulp);
575
576 /**
577 * Claim the bus and prepare it for communication with a given slave.
578 *
579 * This must be called before doing any transfers with a SPI slave. It
580 * will enable and initialize any SPI hardware as necessary, and make
581 * sure that the SCK line is in the correct idle state. It is not
582 * allowed to claim the same bus for several slaves without releasing
583 * the bus in between.
584 *
585 * @dev: The SPI slave device
586 *
587 * Returns: 0 if the bus was claimed successfully, or a negative value
588 * if it wasn't.
589 */
590 int dm_spi_claim_bus(struct udevice *dev);
591
592 /**
593 * Release the SPI bus
594 *
595 * This must be called once for every call to dm_spi_claim_bus() after
596 * all transfers have finished. It may disable any SPI hardware as
597 * appropriate.
598 *
599 * @slave: The SPI slave device
600 */
601 void dm_spi_release_bus(struct udevice *dev);
602
603 /**
604 * SPI transfer
605 *
606 * This writes "bitlen" bits out the SPI MOSI port and simultaneously clocks
607 * "bitlen" bits in the SPI MISO port. That's just the way SPI works.
608 *
609 * The source of the outgoing bits is the "dout" parameter and the
610 * destination of the input bits is the "din" parameter. Note that "dout"
611 * and "din" can point to the same memory location, in which case the
612 * input data overwrites the output data (since both are buffered by
613 * temporary variables, this is OK).
614 *
615 * dm_spi_xfer() interface:
616 * @dev: The SPI slave device which will be sending/receiving the data.
617 * @bitlen: How many bits to write and read.
618 * @dout: Pointer to a string of bits to send out. The bits are
619 * held in a byte array and are sent MSB first.
620 * @din: Pointer to a string of bits that will be filled in.
621 * @flags: A bitwise combination of SPI_XFER_* flags.
622 *
623 * Returns: 0 on success, not 0 on failure
624 */
625 int dm_spi_xfer(struct udevice *dev, unsigned int bitlen,
626 const void *dout, void *din, unsigned long flags);
627
628 /* Access the operations for a SPI device */
629 #define spi_get_ops(dev) ((struct dm_spi_ops *)(dev)->driver->ops)
630 #define spi_emul_get_ops(dev) ((struct dm_spi_emul_ops *)(dev)->driver->ops)
631 #endif /* CONFIG_DM_SPI */
632
633 #endif /* _SPI_H_ */
634