2 * Common SPI Interface: Controller-specific definitions
5 * Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com.
7 * SPDX-License-Identifier: GPL-2.0+
14 #define SPI_CPHA BIT(0) /* clock phase */
15 #define SPI_CPOL BIT(1) /* 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 BIT(2) /* CS active high */
21 #define SPI_LSB_FIRST BIT(3) /* per-word bits-on-wire */
22 #define SPI_3WIRE BIT(4) /* SI/SO signals shared */
23 #define SPI_LOOP BIT(5) /* loopback mode */
24 #define SPI_SLAVE BIT(6) /* slave mode */
25 #define SPI_PREAMBLE BIT(7) /* Skip preamble bytes */
26 #define SPI_TX_BYTE BIT(8) /* transmit with 1 wire byte */
27 #define SPI_TX_DUAL BIT(9) /* transmit with 2 wires */
28 #define SPI_TX_QUAD BIT(10) /* transmit with 4 wires */
29 #define SPI_RX_SLOW BIT(11) /* receive with 1 wire slow */
30 #define SPI_RX_DUAL BIT(12) /* receive with 2 wires */
31 #define SPI_RX_QUAD BIT(13) /* receive with 4 wires */
33 /* Header byte that marks the start of the message */
34 #define SPI_PREAMBLE_END_BYTE 0xec
36 #define SPI_DEFAULT_WORDLEN 8
39 /* TODO(sjg@chromium.org): Remove this and use max_hz from struct spi_slave */
45 * struct dm_spi_platdata - platform data for all SPI slaves
47 * This describes a SPI slave, a child device of the SPI bus. To obtain this
48 * struct from a spi_slave, use dev_get_parent_platdata(dev) or
49 * dev_get_parent_platdata(slave->dev).
51 * This data is immuatable. Each time the device is probed, @max_hz and @mode
52 * will be copied to struct spi_slave.
54 * @cs: Chip select number (0..n-1)
55 * @max_hz: Maximum bus speed that this slave can tolerate
56 * @mode: SPI mode to use for this device (see SPI mode flags)
58 struct dm_spi_slave_platdata {
64 #endif /* CONFIG_DM_SPI */
67 * struct spi_slave - Representation of a SPI slave
69 * For driver model this is the per-child data used by the SPI bus. It can
70 * be accessed using dev_get_parent_priv() on the slave device. The SPI uclass
71 * sets uip per_child_auto_alloc_size to sizeof(struct spi_slave), and the
72 * driver should not override it. Two platform data fields (max_hz and mode)
73 * are copied into this structure to provide an initial value. This allows
74 * them to be changed, since we should never change platform data in drivers.
76 * If not using driver model, drivers are expected to extend this with
77 * controller-specific data.
79 * @dev: SPI slave device
80 * @max_hz: Maximum speed for this slave
81 * @speed: Current bus speed. This is 0 until the bus is first
83 * @bus: ID of the bus that the slave is attached to. For
84 * driver model this is the sequence number of the SPI
85 * bus (bus->seq) so does not need to be stored
86 * @cs: ID of the chip select connected to the slave.
87 * @mode: SPI mode to use for this slave (see SPI mode flags)
88 * @wordlen: Size of SPI word in number of bits
89 * @max_read_size: If non-zero, the maximum number of bytes which can
91 * @max_write_size: If non-zero, the maximum number of bytes which can
93 * @memory_map: Address of read-only SPI flash access.
94 * @flags: Indication of SPI flags.
98 struct udevice *dev; /* struct spi_slave is dev->parentdata */
106 unsigned int wordlen;
107 unsigned int max_read_size;
108 unsigned int max_write_size;
112 #define SPI_XFER_BEGIN BIT(0) /* Assert CS before transfer */
113 #define SPI_XFER_END BIT(1) /* Deassert CS after transfer */
114 #define SPI_XFER_ONCE (SPI_XFER_BEGIN | SPI_XFER_END)
115 #define SPI_XFER_MMAP BIT(2) /* Memory Mapped start */
116 #define SPI_XFER_MMAP_END BIT(3) /* Memory Mapped End */
120 * Initialization, must be called once on start up.
122 * TODO: I don't think we really need this.
127 * spi_do_alloc_slave - Allocate a new SPI slave (internal)
129 * Allocate and zero all fields in the spi slave, and set the bus/chip
130 * select. Use the helper macro spi_alloc_slave() to call this.
132 * @offset: Offset of struct spi_slave within slave structure.
133 * @size: Size of slave structure.
134 * @bus: Bus ID of the slave chip.
135 * @cs: Chip select ID of the slave chip on the specified bus.
137 void *spi_do_alloc_slave(int offset, int size, unsigned int bus,
141 * spi_alloc_slave - Allocate a new SPI slave
143 * Allocate and zero all fields in the spi slave, and set the bus/chip
146 * @_struct: Name of structure to allocate (e.g. struct tegra_spi).
147 * This structure must contain a member 'struct spi_slave *slave'.
148 * @bus: Bus ID of the slave chip.
149 * @cs: Chip select ID of the slave chip on the specified bus.
151 #define spi_alloc_slave(_struct, bus, cs) \
152 spi_do_alloc_slave(offsetof(_struct, slave), \
153 sizeof(_struct), bus, cs)
156 * spi_alloc_slave_base - Allocate a new SPI slave with no private data
158 * Allocate and zero all fields in the spi slave, and set the bus/chip
161 * @bus: Bus ID of the slave chip.
162 * @cs: Chip select ID of the slave chip on the specified bus.
164 #define spi_alloc_slave_base(bus, cs) \
165 spi_do_alloc_slave(0, sizeof(struct spi_slave), bus, cs)
168 * Set up communications parameters for a SPI slave.
170 * This must be called once for each slave. Note that this function
171 * usually doesn't touch any actual hardware, it only initializes the
172 * contents of spi_slave so that the hardware can be easily
175 * @bus: Bus ID of the slave chip.
176 * @cs: Chip select ID of the slave chip on the specified bus.
177 * @max_hz: Maximum SCK rate in Hz.
178 * @mode: Clock polarity, clock phase and other parameters.
180 * Returns: A spi_slave reference that can be used in subsequent SPI
181 * calls, or NULL if one or more of the parameters are not supported.
183 struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
184 unsigned int max_hz, unsigned int mode);
187 * Free any memory associated with a SPI slave.
189 * @slave: The SPI slave
191 void spi_free_slave(struct spi_slave *slave);
194 * Claim the bus and prepare it for communication with a given slave.
196 * This must be called before doing any transfers with a SPI slave. It
197 * will enable and initialize any SPI hardware as necessary, and make
198 * sure that the SCK line is in the correct idle state. It is not
199 * allowed to claim the same bus for several slaves without releasing
200 * the bus in between.
202 * @slave: The SPI slave
204 * Returns: 0 if the bus was claimed successfully, or a negative value
207 int spi_claim_bus(struct spi_slave *slave);
210 * Release the SPI bus
212 * This must be called once for every call to spi_claim_bus() after
213 * all transfers have finished. It may disable any SPI hardware as
216 * @slave: The SPI slave
218 void spi_release_bus(struct spi_slave *slave);
221 * Set the word length for SPI transactions
223 * Set the word length (number of bits per word) for SPI transactions.
225 * @slave: The SPI slave
226 * @wordlen: The number of bits in a word
228 * Returns: 0 on success, -1 on failure.
230 int spi_set_wordlen(struct spi_slave *slave, unsigned int wordlen);
235 * This writes "bitlen" bits out the SPI MOSI port and simultaneously clocks
236 * "bitlen" bits in the SPI MISO port. That's just the way SPI works.
238 * The source of the outgoing bits is the "dout" parameter and the
239 * destination of the input bits is the "din" parameter. Note that "dout"
240 * and "din" can point to the same memory location, in which case the
241 * input data overwrites the output data (since both are buffered by
242 * temporary variables, this is OK).
244 * spi_xfer() interface:
245 * @slave: The SPI slave which will be sending/receiving the data.
246 * @bitlen: How many bits to write and read.
247 * @dout: Pointer to a string of bits to send out. The bits are
248 * held in a byte array and are sent MSB first.
249 * @din: Pointer to a string of bits that will be filled in.
250 * @flags: A bitwise combination of SPI_XFER_* flags.
252 * Returns: 0 on success, not 0 on failure
254 int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
255 void *din, unsigned long flags);
257 /* Copy memory mapped data */
258 void spi_flash_copy_mmap(void *data, void *offset, size_t len);
261 * Determine if a SPI chipselect is valid.
262 * This function is provided by the board if the low-level SPI driver
263 * needs it to determine if a given chipselect is actually valid.
265 * Returns: 1 if bus:cs identifies a valid chip on this board, 0
268 int spi_cs_is_valid(unsigned int bus, unsigned int cs);
270 #ifndef CONFIG_DM_SPI
272 * Activate a SPI chipselect.
273 * This function is provided by the board code when using a driver
274 * that can't control its chipselects automatically (e.g.
275 * common/soft_spi.c). When called, it should activate the chip select
276 * to the device identified by "slave".
278 void spi_cs_activate(struct spi_slave *slave);
281 * Deactivate a SPI chipselect.
282 * This function is provided by the board code when using a driver
283 * that can't control its chipselects automatically (e.g.
284 * common/soft_spi.c). When called, it should deactivate the chip
285 * select to the device identified by "slave".
287 void spi_cs_deactivate(struct spi_slave *slave);
290 * Set transfer speed.
291 * This sets a new speed to be applied for next spi_xfer().
292 * @slave: The SPI slave
293 * @hz: The transfer speed
295 void spi_set_speed(struct spi_slave *slave, uint hz);
299 * Write 8 bits, then read 8 bits.
300 * @slave: The SPI slave we're communicating with
301 * @byte: Byte to be written
303 * Returns: The value that was read, or a negative value on error.
305 * TODO: This function probably shouldn't be inlined.
307 static inline int spi_w8r8(struct spi_slave *slave, unsigned char byte)
309 unsigned char dout[2];
310 unsigned char din[2];
316 ret = spi_xfer(slave, 16, dout, din, SPI_XFER_BEGIN | SPI_XFER_END);
317 return ret < 0 ? ret : din[1];
321 * Set up a SPI slave for a particular device tree node
323 * This calls spi_setup_slave() with the correct bus number. Call
324 * spi_free_slave() to free it later.
326 * @param blob: Device tree blob
327 * @param slave_node: Slave node to use
328 * @param spi_node: SPI peripheral node to use
329 * @return pointer to new spi_slave structure
331 struct spi_slave *spi_setup_slave_fdt(const void *blob, int slave_node,
336 * struct spi_cs_info - Information about a bus chip select
338 * @dev: Connected device, or NULL if none
345 * struct struct dm_spi_ops - Driver model SPI operations
347 * The uclass interface is implemented by all SPI devices which use
352 * Claim the bus and prepare it for communication.
354 * The device provided is the slave device. It's parent controller
355 * will be used to provide the communication.
357 * This must be called before doing any transfers with a SPI slave. It
358 * will enable and initialize any SPI hardware as necessary, and make
359 * sure that the SCK line is in the correct idle state. It is not
360 * allowed to claim the same bus for several slaves without releasing
361 * the bus in between.
363 * @dev: The SPI slave
365 * Returns: 0 if the bus was claimed successfully, or a negative value
368 int (*claim_bus)(struct udevice *dev);
371 * Release the SPI bus
373 * This must be called once for every call to spi_claim_bus() after
374 * all transfers have finished. It may disable any SPI hardware as
377 * @dev: The SPI slave
379 int (*release_bus)(struct udevice *dev);
382 * Set the word length for SPI transactions
384 * Set the word length (number of bits per word) for SPI transactions.
386 * @bus: The SPI slave
387 * @wordlen: The number of bits in a word
389 * Returns: 0 on success, -ve on failure.
391 int (*set_wordlen)(struct udevice *dev, unsigned int wordlen);
396 * This writes "bitlen" bits out the SPI MOSI port and simultaneously
397 * clocks "bitlen" bits in the SPI MISO port. That's just the way SPI
400 * The source of the outgoing bits is the "dout" parameter and the
401 * destination of the input bits is the "din" parameter. Note that
402 * "dout" and "din" can point to the same memory location, in which
403 * case the input data overwrites the output data (since both are
404 * buffered by temporary variables, this is OK).
406 * spi_xfer() interface:
407 * @dev: The slave device to communicate with
408 * @bitlen: How many bits to write and read.
409 * @dout: Pointer to a string of bits to send out. The bits are
410 * held in a byte array and are sent MSB first.
411 * @din: Pointer to a string of bits that will be filled in.
412 * @flags: A bitwise combination of SPI_XFER_* flags.
414 * Returns: 0 on success, not -1 on failure
416 int (*xfer)(struct udevice *dev, unsigned int bitlen, const void *dout,
417 void *din, unsigned long flags);
420 * Set transfer speed.
421 * This sets a new speed to be applied for next spi_xfer().
423 * @hz: The transfer speed
424 * @return 0 if OK, -ve on error
426 int (*set_speed)(struct udevice *bus, uint hz);
429 * Set the SPI mode/flags
431 * It is unclear if we want to set speed and mode together instead
435 * @mode: Requested SPI mode (SPI_... flags)
436 * @return 0 if OK, -ve on error
438 int (*set_mode)(struct udevice *bus, uint mode);
441 * Get information on a chip select
443 * This is only called when the SPI uclass does not know about a
444 * chip select, i.e. it has no attached device. It gives the driver
445 * a chance to allow activity on that chip select even so.
448 * @cs: The chip select (0..n-1)
449 * @info: Returns information about the chip select, if valid.
450 * On entry info->dev is NULL
451 * @return 0 if OK (and @info is set up), -ENODEV if the chip select
452 * is invalid, other -ve value on error
454 int (*cs_info)(struct udevice *bus, uint cs, struct spi_cs_info *info);
457 struct dm_spi_emul_ops {
461 * This writes "bitlen" bits out the SPI MOSI port and simultaneously
462 * clocks "bitlen" bits in the SPI MISO port. That's just the way SPI
463 * works. Here the device is a slave.
465 * The source of the outgoing bits is the "dout" parameter and the
466 * destination of the input bits is the "din" parameter. Note that
467 * "dout" and "din" can point to the same memory location, in which
468 * case the input data overwrites the output data (since both are
469 * buffered by temporary variables, this is OK).
471 * spi_xfer() interface:
472 * @slave: The SPI slave which will be sending/receiving the data.
473 * @bitlen: How many bits to write and read.
474 * @dout: Pointer to a string of bits sent to the device. The
475 * bits are held in a byte array and are sent MSB first.
476 * @din: Pointer to a string of bits that will be sent back to
478 * @flags: A bitwise combination of SPI_XFER_* flags.
480 * Returns: 0 on success, not -1 on failure
482 int (*xfer)(struct udevice *slave, unsigned int bitlen,
483 const void *dout, void *din, unsigned long flags);
487 * spi_find_bus_and_cs() - Find bus and slave devices by number
489 * Given a bus number and chip select, this finds the corresponding bus
490 * device and slave device. Neither device is activated by this function,
491 * although they may have been activated previously.
493 * @busnum: SPI bus number
494 * @cs: Chip select to look for
495 * @busp: Returns bus device
496 * @devp: Return slave device
497 * @return 0 if found, -ENODEV on error
499 int spi_find_bus_and_cs(int busnum, int cs, struct udevice **busp,
500 struct udevice **devp);
503 * spi_get_bus_and_cs() - Find and activate bus and slave devices by number
505 * Given a bus number and chip select, this finds the corresponding bus
506 * device and slave device.
508 * If no such slave exists, and drv_name is not NULL, then a new slave device
509 * is automatically bound on this chip select.
511 * Ths new slave device is probed ready for use with the given speed and mode.
513 * @busnum: SPI bus number
514 * @cs: Chip select to look for
515 * @speed: SPI speed to use for this slave
516 * @mode: SPI mode to use for this slave
517 * @drv_name: Name of driver to attach to this chip select
518 * @dev_name: Name of the new device thus created
519 * @busp: Returns bus device
520 * @devp: Return slave device
521 * @return 0 if found, -ve on error
523 int spi_get_bus_and_cs(int busnum, int cs, int speed, int mode,
524 const char *drv_name, const char *dev_name,
525 struct udevice **busp, struct spi_slave **devp);
528 * spi_chip_select() - Get the chip select for a slave
530 * @return the chip select this slave is attached to
532 int spi_chip_select(struct udevice *slave);
535 * spi_find_chip_select() - Find the slave attached to chip select
537 * @bus: SPI bus to search
538 * @cs: Chip select to look for
539 * @devp: Returns the slave device if found
540 * @return 0 if found, -ENODEV on error
542 int spi_find_chip_select(struct udevice *bus, int cs, struct udevice **devp);
545 * spi_slave_ofdata_to_platdata() - decode standard SPI platform data
547 * This decodes the speed and mode for a slave from a device tree node
549 * @blob: Device tree blob
550 * @node: Node offset to read from
551 * @plat: Place to put the decoded information
553 int spi_slave_ofdata_to_platdata(struct udevice *dev,
554 struct dm_spi_slave_platdata *plat);
557 * spi_cs_info() - Check information on a chip select
559 * This checks a particular chip select on a bus to see if it has a device
560 * attached, or is even valid.
563 * @cs: The chip select (0..n-1)
564 * @info: Returns information about the chip select, if valid
565 * @return 0 if OK (and @info is set up), -ENODEV if the chip select
566 * is invalid, other -ve value on error
568 int spi_cs_info(struct udevice *bus, uint cs, struct spi_cs_info *info);
570 struct sandbox_state;
573 * sandbox_spi_get_emul() - get an emulator for a SPI slave
575 * This provides a way to attach an emulated SPI device to a particular SPI
576 * slave, so that xfer() operations on the slave will be handled by the
577 * emulator. If a emulator already exists on that chip select it is returned.
578 * Otherwise one is created.
580 * @state: Sandbox state
581 * @bus: SPI bus requesting the emulator
582 * @slave: SPI slave device requesting the emulator
583 * @emuip: Returns pointer to emulator
584 * @return 0 if OK, -ve on error
586 int sandbox_spi_get_emul(struct sandbox_state *state,
587 struct udevice *bus, struct udevice *slave,
588 struct udevice **emulp);
591 * Claim the bus and prepare it for communication with a given slave.
593 * This must be called before doing any transfers with a SPI slave. It
594 * will enable and initialize any SPI hardware as necessary, and make
595 * sure that the SCK line is in the correct idle state. It is not
596 * allowed to claim the same bus for several slaves without releasing
597 * the bus in between.
599 * @dev: The SPI slave device
601 * Returns: 0 if the bus was claimed successfully, or a negative value
604 int dm_spi_claim_bus(struct udevice *dev);
607 * Release the SPI bus
609 * This must be called once for every call to dm_spi_claim_bus() after
610 * all transfers have finished. It may disable any SPI hardware as
613 * @slave: The SPI slave device
615 void dm_spi_release_bus(struct udevice *dev);
620 * This writes "bitlen" bits out the SPI MOSI port and simultaneously clocks
621 * "bitlen" bits in the SPI MISO port. That's just the way SPI works.
623 * The source of the outgoing bits is the "dout" parameter and the
624 * destination of the input bits is the "din" parameter. Note that "dout"
625 * and "din" can point to the same memory location, in which case the
626 * input data overwrites the output data (since both are buffered by
627 * temporary variables, this is OK).
629 * dm_spi_xfer() interface:
630 * @dev: The SPI slave device which will be sending/receiving the data.
631 * @bitlen: How many bits to write and read.
632 * @dout: Pointer to a string of bits to send out. The bits are
633 * held in a byte array and are sent MSB first.
634 * @din: Pointer to a string of bits that will be filled in.
635 * @flags: A bitwise combination of SPI_XFER_* flags.
637 * Returns: 0 on success, not 0 on failure
639 int dm_spi_xfer(struct udevice *dev, unsigned int bitlen,
640 const void *dout, void *din, unsigned long flags);
642 /* Access the operations for a SPI device */
643 #define spi_get_ops(dev) ((struct dm_spi_ops *)(dev)->driver->ops)
644 #define spi_emul_get_ops(dev) ((struct dm_spi_emul_ops *)(dev)->driver->ops)
645 #endif /* CONFIG_DM_SPI */