xref: /openbmc/u-boot/include/spi.h (revision c3d89140)
1 /*
2  * Common SPI Interface: Controller-specific definitions
3  *
4  * (C) Copyright 2001
5  * Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com.
6  *
7  * SPDX-License-Identifier:	GPL-2.0+
8  */
9 
10 #ifndef _SPI_H_
11 #define _SPI_H_
12 
13 /* SPI mode flags */
14 #define	SPI_CPHA	0x01			/* clock phase */
15 #define	SPI_CPOL	0x02			/* clock polarity */
16 #define	SPI_MODE_0	(0|0)			/* (original MicroWire) */
17 #define	SPI_MODE_1	(0|SPI_CPHA)
18 #define	SPI_MODE_2	(SPI_CPOL|0)
19 #define	SPI_MODE_3	(SPI_CPOL|SPI_CPHA)
20 #define	SPI_CS_HIGH	0x04			/* CS active high */
21 #define	SPI_LSB_FIRST	0x08			/* per-word bits-on-wire */
22 #define	SPI_3WIRE	0x10			/* SI/SO signals shared */
23 #define	SPI_LOOP	0x20			/* loopback mode */
24 #define	SPI_SLAVE	0x40			/* slave mode */
25 #define	SPI_PREAMBLE	0x80			/* Skip preamble bytes */
26 
27 /* SPI transfer flags */
28 #define SPI_XFER_BEGIN		0x01	/* Assert CS before transfer */
29 #define SPI_XFER_END		0x02	/* Deassert CS after transfer */
30 #define SPI_XFER_MMAP		0x08	/* Memory Mapped start */
31 #define SPI_XFER_MMAP_END	0x10	/* Memory Mapped End */
32 #define SPI_XFER_ONCE		(SPI_XFER_BEGIN | SPI_XFER_END)
33 #define SPI_XFER_U_PAGE	(1 << 5)
34 
35 /* SPI TX operation modes */
36 #define SPI_OPM_TX_QPP		(1 << 0)
37 #define SPI_OPM_TX_BP		(1 << 1)
38 
39 /* SPI RX operation modes */
40 #define SPI_OPM_RX_AS		(1 << 0)
41 #define SPI_OPM_RX_AF		(1 << 1)
42 #define SPI_OPM_RX_DOUT		(1 << 2)
43 #define SPI_OPM_RX_DIO		(1 << 3)
44 #define SPI_OPM_RX_QOF		(1 << 4)
45 #define SPI_OPM_RX_QIOF		(1 << 5)
46 #define SPI_OPM_RX_EXTN	(SPI_OPM_RX_AS | SPI_OPM_RX_AF | SPI_OPM_RX_DOUT | \
47 				SPI_OPM_RX_DIO | SPI_OPM_RX_QOF | \
48 				SPI_OPM_RX_QIOF)
49 
50 /* SPI bus connection options - see enum spi_dual_flash */
51 #define SPI_CONN_DUAL_SHARED		(1 << 0)
52 #define SPI_CONN_DUAL_SEPARATED	(1 << 1)
53 
54 /* Header byte that marks the start of the message */
55 #define SPI_PREAMBLE_END_BYTE	0xec
56 
57 #define SPI_DEFAULT_WORDLEN	8
58 
59 #ifdef CONFIG_DM_SPI
60 /* TODO(sjg@chromium.org): Remove this and use max_hz from struct spi_slave */
61 struct dm_spi_bus {
62 	uint max_hz;
63 };
64 
65 /**
66  * struct dm_spi_platdata - platform data for all SPI slaves
67  *
68  * This describes a SPI slave, a child device of the SPI bus. To obtain this
69  * struct from a spi_slave, use dev_get_parent_platdata(dev) or
70  * dev_get_parent_platdata(slave->dev).
71  *
72  * This data is immuatable. Each time the device is probed, @max_hz and @mode
73  * will be copied to struct spi_slave.
74  *
75  * @cs:		Chip select number (0..n-1)
76  * @max_hz:	Maximum bus speed that this slave can tolerate
77  * @mode:	SPI mode to use for this device (see SPI mode flags)
78  */
79 struct dm_spi_slave_platdata {
80 	unsigned int cs;
81 	uint max_hz;
82 	uint mode;
83 };
84 
85 #endif /* CONFIG_DM_SPI */
86 
87 /**
88  * struct spi_slave - Representation of a SPI slave
89  *
90  * For driver model this is the per-child data used by the SPI bus. It can
91  * be accessed using dev_get_parentdata() on the slave device. The SPI uclass
92  * sets uip per_child_auto_alloc_size to sizeof(struct spi_slave), and the
93  * driver should not override it. Two platform data fields (max_hz and mode)
94  * are copied into this structure to provide an initial value. This allows
95  * them to be changed, since we should never change platform data in drivers.
96  *
97  * If not using driver model, drivers are expected to extend this with
98  * controller-specific data.
99  *
100  * @dev:		SPI slave device
101  * @max_hz:		Maximum speed for this slave
102  * @mode:		SPI mode to use for this slave (see SPI mode flags)
103  * @speed:		Current bus speed. This is 0 until the bus is first
104  *			claimed.
105  * @bus:		ID of the bus that the slave is attached to. For
106  *			driver model this is the sequence number of the SPI
107  *			bus (bus->seq) so does not need to be stored
108  * @cs:			ID of the chip select connected to the slave.
109  * @op_mode_rx:		SPI RX operation mode.
110  * @op_mode_tx:		SPI TX operation mode.
111  * @wordlen:		Size of SPI word in number of bits
112  * @max_write_size:	If non-zero, the maximum number of bytes which can
113  *			be written at once, excluding command bytes.
114  * @memory_map:		Address of read-only SPI flash access.
115  * @option:		Varies SPI bus options - separate, shared bus.
116  * @flags:		Indication of SPI flags.
117  */
118 struct spi_slave {
119 #ifdef CONFIG_DM_SPI
120 	struct udevice *dev;	/* struct spi_slave is dev->parentdata */
121 	uint max_hz;
122 	uint speed;
123 	uint mode;
124 #else
125 	unsigned int bus;
126 	unsigned int cs;
127 #endif
128 	u8 op_mode_rx;
129 	u8 op_mode_tx;
130 	unsigned int wordlen;
131 	unsigned int max_write_size;
132 	void *memory_map;
133 	u8 option;
134 	u8 flags;
135 };
136 
137 /**
138  * Initialization, must be called once on start up.
139  *
140  * TODO: I don't think we really need this.
141  */
142 void spi_init(void);
143 
144 /**
145  * spi_do_alloc_slave - Allocate a new SPI slave (internal)
146  *
147  * Allocate and zero all fields in the spi slave, and set the bus/chip
148  * select. Use the helper macro spi_alloc_slave() to call this.
149  *
150  * @offset:	Offset of struct spi_slave within slave structure.
151  * @size:	Size of slave structure.
152  * @bus:	Bus ID of the slave chip.
153  * @cs:		Chip select ID of the slave chip on the specified bus.
154  */
155 void *spi_do_alloc_slave(int offset, int size, unsigned int bus,
156 			 unsigned int cs);
157 
158 /**
159  * spi_alloc_slave - Allocate a new SPI slave
160  *
161  * Allocate and zero all fields in the spi slave, and set the bus/chip
162  * select.
163  *
164  * @_struct:	Name of structure to allocate (e.g. struct tegra_spi).
165  *		This structure must contain a member 'struct spi_slave *slave'.
166  * @bus:	Bus ID of the slave chip.
167  * @cs:		Chip select ID of the slave chip on the specified bus.
168  */
169 #define spi_alloc_slave(_struct, bus, cs) \
170 	spi_do_alloc_slave(offsetof(_struct, slave), \
171 			    sizeof(_struct), bus, cs)
172 
173 /**
174  * spi_alloc_slave_base - Allocate a new SPI slave with no private data
175  *
176  * Allocate and zero all fields in the spi slave, and set the bus/chip
177  * select.
178  *
179  * @bus:	Bus ID of the slave chip.
180  * @cs:		Chip select ID of the slave chip on the specified bus.
181  */
182 #define spi_alloc_slave_base(bus, cs) \
183 	spi_do_alloc_slave(0, sizeof(struct spi_slave), bus, cs)
184 
185 /**
186  * Set up communications parameters for a SPI slave.
187  *
188  * This must be called once for each slave. Note that this function
189  * usually doesn't touch any actual hardware, it only initializes the
190  * contents of spi_slave so that the hardware can be easily
191  * initialized later.
192  *
193  * @bus:	Bus ID of the slave chip.
194  * @cs:		Chip select ID of the slave chip on the specified bus.
195  * @max_hz:	Maximum SCK rate in Hz.
196  * @mode:	Clock polarity, clock phase and other parameters.
197  *
198  * Returns: A spi_slave reference that can be used in subsequent SPI
199  * calls, or NULL if one or more of the parameters are not supported.
200  */
201 struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
202 		unsigned int max_hz, unsigned int mode);
203 
204 /**
205  * Free any memory associated with a SPI slave.
206  *
207  * @slave:	The SPI slave
208  */
209 void spi_free_slave(struct spi_slave *slave);
210 
211 /**
212  * Claim the bus and prepare it for communication with a given slave.
213  *
214  * This must be called before doing any transfers with a SPI slave. It
215  * will enable and initialize any SPI hardware as necessary, and make
216  * sure that the SCK line is in the correct idle state. It is not
217  * allowed to claim the same bus for several slaves without releasing
218  * the bus in between.
219  *
220  * @slave:	The SPI slave
221  *
222  * Returns: 0 if the bus was claimed successfully, or a negative value
223  * if it wasn't.
224  */
225 int spi_claim_bus(struct spi_slave *slave);
226 
227 /**
228  * Release the SPI bus
229  *
230  * This must be called once for every call to spi_claim_bus() after
231  * all transfers have finished. It may disable any SPI hardware as
232  * appropriate.
233  *
234  * @slave:	The SPI slave
235  */
236 void spi_release_bus(struct spi_slave *slave);
237 
238 /**
239  * Set the word length for SPI transactions
240  *
241  * Set the word length (number of bits per word) for SPI transactions.
242  *
243  * @slave:	The SPI slave
244  * @wordlen:	The number of bits in a word
245  *
246  * Returns: 0 on success, -1 on failure.
247  */
248 int spi_set_wordlen(struct spi_slave *slave, unsigned int wordlen);
249 
250 /**
251  * SPI transfer
252  *
253  * This writes "bitlen" bits out the SPI MOSI port and simultaneously clocks
254  * "bitlen" bits in the SPI MISO port.  That's just the way SPI works.
255  *
256  * The source of the outgoing bits is the "dout" parameter and the
257  * destination of the input bits is the "din" parameter.  Note that "dout"
258  * and "din" can point to the same memory location, in which case the
259  * input data overwrites the output data (since both are buffered by
260  * temporary variables, this is OK).
261  *
262  * spi_xfer() interface:
263  * @slave:	The SPI slave which will be sending/receiving the data.
264  * @bitlen:	How many bits to write and read.
265  * @dout:	Pointer to a string of bits to send out.  The bits are
266  *		held in a byte array and are sent MSB first.
267  * @din:	Pointer to a string of bits that will be filled in.
268  * @flags:	A bitwise combination of SPI_XFER_* flags.
269  *
270  * Returns: 0 on success, not 0 on failure
271  */
272 int  spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
273 		void *din, unsigned long flags);
274 
275 /* Copy memory mapped data */
276 void spi_flash_copy_mmap(void *data, void *offset, size_t len);
277 
278 /**
279  * Determine if a SPI chipselect is valid.
280  * This function is provided by the board if the low-level SPI driver
281  * needs it to determine if a given chipselect is actually valid.
282  *
283  * Returns: 1 if bus:cs identifies a valid chip on this board, 0
284  * otherwise.
285  */
286 int spi_cs_is_valid(unsigned int bus, unsigned int cs);
287 
288 #ifndef CONFIG_DM_SPI
289 /**
290  * Activate a SPI chipselect.
291  * This function is provided by the board code when using a driver
292  * that can't control its chipselects automatically (e.g.
293  * common/soft_spi.c). When called, it should activate the chip select
294  * to the device identified by "slave".
295  */
296 void spi_cs_activate(struct spi_slave *slave);
297 
298 /**
299  * Deactivate a SPI chipselect.
300  * This function is provided by the board code when using a driver
301  * that can't control its chipselects automatically (e.g.
302  * common/soft_spi.c). When called, it should deactivate the chip
303  * select to the device identified by "slave".
304  */
305 void spi_cs_deactivate(struct spi_slave *slave);
306 
307 /**
308  * Set transfer speed.
309  * This sets a new speed to be applied for next spi_xfer().
310  * @slave:	The SPI slave
311  * @hz:		The transfer speed
312  */
313 void spi_set_speed(struct spi_slave *slave, uint hz);
314 #endif
315 
316 /**
317  * Write 8 bits, then read 8 bits.
318  * @slave:	The SPI slave we're communicating with
319  * @byte:	Byte to be written
320  *
321  * Returns: The value that was read, or a negative value on error.
322  *
323  * TODO: This function probably shouldn't be inlined.
324  */
325 static inline int spi_w8r8(struct spi_slave *slave, unsigned char byte)
326 {
327 	unsigned char dout[2];
328 	unsigned char din[2];
329 	int ret;
330 
331 	dout[0] = byte;
332 	dout[1] = 0;
333 
334 	ret = spi_xfer(slave, 16, dout, din, SPI_XFER_BEGIN | SPI_XFER_END);
335 	return ret < 0 ? ret : din[1];
336 }
337 
338 /**
339  * Set up a SPI slave for a particular device tree node
340  *
341  * This calls spi_setup_slave() with the correct bus number. Call
342  * spi_free_slave() to free it later.
343  *
344  * @param blob:		Device tree blob
345  * @param slave_node:	Slave node to use
346  * @param spi_node:	SPI peripheral node to use
347  * @return pointer to new spi_slave structure
348  */
349 struct spi_slave *spi_setup_slave_fdt(const void *blob, int slave_node,
350 				      int spi_node);
351 
352 /**
353  * spi_base_setup_slave_fdt() - helper function to set up a SPI slace
354  *
355  * This decodes SPI properties from the slave node to determine the
356  * chip select and SPI parameters.
357  *
358  * @blob:	Device tree blob
359  * @busnum:	Bus number to use
360  * @node:	Device tree node for the SPI bus
361  */
362 struct spi_slave *spi_base_setup_slave_fdt(const void *blob, int busnum,
363 					   int node);
364 
365 #ifdef CONFIG_DM_SPI
366 
367 /**
368  * struct spi_cs_info - Information about a bus chip select
369  *
370  * @dev:	Connected device, or NULL if none
371  */
372 struct spi_cs_info {
373 	struct udevice *dev;
374 };
375 
376 /**
377  * struct struct dm_spi_ops - Driver model SPI operations
378  *
379  * The uclass interface is implemented by all SPI devices which use
380  * driver model.
381  */
382 struct dm_spi_ops {
383 	/**
384 	 * Claim the bus and prepare it for communication.
385 	 *
386 	 * The device provided is the slave device. It's parent controller
387 	 * will be used to provide the communication.
388 	 *
389 	 * This must be called before doing any transfers with a SPI slave. It
390 	 * will enable and initialize any SPI hardware as necessary, and make
391 	 * sure that the SCK line is in the correct idle state. It is not
392 	 * allowed to claim the same bus for several slaves without releasing
393 	 * the bus in between.
394 	 *
395 	 * @dev:	The SPI slave
396 	 *
397 	 * Returns: 0 if the bus was claimed successfully, or a negative value
398 	 * if it wasn't.
399 	 */
400 	int (*claim_bus)(struct udevice *dev);
401 
402 	/**
403 	 * Release the SPI bus
404 	 *
405 	 * This must be called once for every call to spi_claim_bus() after
406 	 * all transfers have finished. It may disable any SPI hardware as
407 	 * appropriate.
408 	 *
409 	 * @dev:	The SPI slave
410 	 */
411 	int (*release_bus)(struct udevice *dev);
412 
413 	/**
414 	 * Set the word length for SPI transactions
415 	 *
416 	 * Set the word length (number of bits per word) for SPI transactions.
417 	 *
418 	 * @bus:	The SPI slave
419 	 * @wordlen:	The number of bits in a word
420 	 *
421 	 * Returns: 0 on success, -ve on failure.
422 	 */
423 	int (*set_wordlen)(struct udevice *dev, unsigned int wordlen);
424 
425 	/**
426 	 * SPI transfer
427 	 *
428 	 * This writes "bitlen" bits out the SPI MOSI port and simultaneously
429 	 * clocks "bitlen" bits in the SPI MISO port.  That's just the way SPI
430 	 * works.
431 	 *
432 	 * The source of the outgoing bits is the "dout" parameter and the
433 	 * destination of the input bits is the "din" parameter.  Note that
434 	 * "dout" and "din" can point to the same memory location, in which
435 	 * case the input data overwrites the output data (since both are
436 	 * buffered by temporary variables, this is OK).
437 	 *
438 	 * spi_xfer() interface:
439 	 * @dev:	The slave device to communicate with
440 	 * @bitlen:	How many bits to write and read.
441 	 * @dout:	Pointer to a string of bits to send out.  The bits are
442 	 *		held in a byte array and are sent MSB first.
443 	 * @din:	Pointer to a string of bits that will be filled in.
444 	 * @flags:	A bitwise combination of SPI_XFER_* flags.
445 	 *
446 	 * Returns: 0 on success, not -1 on failure
447 	 */
448 	int (*xfer)(struct udevice *dev, unsigned int bitlen, const void *dout,
449 		    void *din, unsigned long flags);
450 
451 	/**
452 	 * Set transfer speed.
453 	 * This sets a new speed to be applied for next spi_xfer().
454 	 * @bus:	The SPI bus
455 	 * @hz:		The transfer speed
456 	 * @return 0 if OK, -ve on error
457 	 */
458 	int (*set_speed)(struct udevice *bus, uint hz);
459 
460 	/**
461 	 * Set the SPI mode/flags
462 	 *
463 	 * It is unclear if we want to set speed and mode together instead
464 	 * of separately.
465 	 *
466 	 * @bus:	The SPI bus
467 	 * @mode:	Requested SPI mode (SPI_... flags)
468 	 * @return 0 if OK, -ve on error
469 	 */
470 	int (*set_mode)(struct udevice *bus, uint mode);
471 
472 	/**
473 	 * Get information on a chip select
474 	 *
475 	 * This is only called when the SPI uclass does not know about a
476 	 * chip select, i.e. it has no attached device. It gives the driver
477 	 * a chance to allow activity on that chip select even so.
478 	 *
479 	 * @bus:	The SPI bus
480 	 * @cs:		The chip select (0..n-1)
481 	 * @info:	Returns information about the chip select, if valid.
482 	 *		On entry info->dev is NULL
483 	 * @return 0 if OK (and @info is set up), -ENODEV if the chip select
484 	 *	   is invalid, other -ve value on error
485 	 */
486 	int (*cs_info)(struct udevice *bus, uint cs, struct spi_cs_info *info);
487 };
488 
489 struct dm_spi_emul_ops {
490 	/**
491 	 * SPI transfer
492 	 *
493 	 * This writes "bitlen" bits out the SPI MOSI port and simultaneously
494 	 * clocks "bitlen" bits in the SPI MISO port.  That's just the way SPI
495 	 * works. Here the device is a slave.
496 	 *
497 	 * The source of the outgoing bits is the "dout" parameter and the
498 	 * destination of the input bits is the "din" parameter.  Note that
499 	 * "dout" and "din" can point to the same memory location, in which
500 	 * case the input data overwrites the output data (since both are
501 	 * buffered by temporary variables, this is OK).
502 	 *
503 	 * spi_xfer() interface:
504 	 * @slave:	The SPI slave which will be sending/receiving the data.
505 	 * @bitlen:	How many bits to write and read.
506 	 * @dout:	Pointer to a string of bits sent to the device. The
507 	 *		bits are held in a byte array and are sent MSB first.
508 	 * @din:	Pointer to a string of bits that will be sent back to
509 	 *		the master.
510 	 * @flags:	A bitwise combination of SPI_XFER_* flags.
511 	 *
512 	 * Returns: 0 on success, not -1 on failure
513 	 */
514 	int (*xfer)(struct udevice *slave, unsigned int bitlen,
515 		    const void *dout, void *din, unsigned long flags);
516 };
517 
518 /**
519  * spi_find_bus_and_cs() - Find bus and slave devices by number
520  *
521  * Given a bus number and chip select, this finds the corresponding bus
522  * device and slave device. Neither device is activated by this function,
523  * although they may have been activated previously.
524  *
525  * @busnum:	SPI bus number
526  * @cs:		Chip select to look for
527  * @busp:	Returns bus device
528  * @devp:	Return slave device
529  * @return 0 if found, -ENODEV on error
530  */
531 int spi_find_bus_and_cs(int busnum, int cs, struct udevice **busp,
532 			struct udevice **devp);
533 
534 /**
535  * spi_get_bus_and_cs() - Find and activate bus and slave devices by number
536  *
537  * Given a bus number and chip select, this finds the corresponding bus
538  * device and slave device.
539  *
540  * If no such slave exists, and drv_name is not NULL, then a new slave device
541  * is automatically bound on this chip select.
542  *
543  * Ths new slave device is probed ready for use with the given speed and mode.
544  *
545  * @busnum:	SPI bus number
546  * @cs:		Chip select to look for
547  * @speed:	SPI speed to use for this slave
548  * @mode:	SPI mode to use for this slave
549  * @drv_name:	Name of driver to attach to this chip select
550  * @dev_name:	Name of the new device thus created
551  * @busp:	Returns bus device
552  * @devp:	Return slave device
553  * @return 0 if found, -ve on error
554  */
555 int spi_get_bus_and_cs(int busnum, int cs, int speed, int mode,
556 			const char *drv_name, const char *dev_name,
557 			struct udevice **busp, struct spi_slave **devp);
558 
559 /**
560  * spi_chip_select() - Get the chip select for a slave
561  *
562  * @return the chip select this slave is attached to
563  */
564 int spi_chip_select(struct udevice *slave);
565 
566 /**
567  * spi_find_chip_select() - Find the slave attached to chip select
568  *
569  * @bus:	SPI bus to search
570  * @cs:		Chip select to look for
571  * @devp:	Returns the slave device if found
572  * @return 0 if found, -ENODEV on error
573  */
574 int spi_find_chip_select(struct udevice *bus, int cs, struct udevice **devp);
575 
576 /**
577  * spi_slave_ofdata_to_platdata() - decode standard SPI platform data
578  *
579  * This decodes the speed and mode for a slave from a device tree node
580  *
581  * @blob:	Device tree blob
582  * @node:	Node offset to read from
583  * @plat:	Place to put the decoded information
584  */
585 int spi_slave_ofdata_to_platdata(const void *blob, int node,
586 				 struct dm_spi_slave_platdata *plat);
587 
588 /**
589  * spi_cs_info() - Check information on a chip select
590  *
591  * This checks a particular chip select on a bus to see if it has a device
592  * attached, or is even valid.
593  *
594  * @bus:	The SPI bus
595  * @cs:		The chip select (0..n-1)
596  * @info:	Returns information about the chip select, if valid
597  * @return 0 if OK (and @info is set up), -ENODEV if the chip select
598  *	   is invalid, other -ve value on error
599  */
600 int spi_cs_info(struct udevice *bus, uint cs, struct spi_cs_info *info);
601 
602 struct sandbox_state;
603 
604 /**
605  * sandbox_spi_get_emul() - get an emulator for a SPI slave
606  *
607  * This provides a way to attach an emulated SPI device to a particular SPI
608  * slave, so that xfer() operations on the slave will be handled by the
609  * emulator. If a emulator already exists on that chip select it is returned.
610  * Otherwise one is created.
611  *
612  * @state:	Sandbox state
613  * @bus:	SPI bus requesting the emulator
614  * @slave:	SPI slave device requesting the emulator
615  * @emuip:	Returns pointer to emulator
616  * @return 0 if OK, -ve on error
617  */
618 int sandbox_spi_get_emul(struct sandbox_state *state,
619 			 struct udevice *bus, struct udevice *slave,
620 			 struct udevice **emulp);
621 
622 /* Access the operations for a SPI device */
623 #define spi_get_ops(dev)	((struct dm_spi_ops *)(dev)->driver->ops)
624 #define spi_emul_get_ops(dev)	((struct dm_spi_emul_ops *)(dev)->driver->ops)
625 #endif /* CONFIG_DM_SPI */
626 
627 #endif	/* _SPI_H_ */
628