1 /* SPDX-License-Identifier: GPL-2.0+ */
3 * Common SPI Interface: Controller-specific definitions
6 * Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com.
15 #define SPI_CPHA BIT(0) /* clock phase */
16 #define SPI_CPOL BIT(1) /* clock polarity */
17 #define SPI_MODE_0 (0|0) /* (original MicroWire) */
18 #define SPI_MODE_1 (0|SPI_CPHA)
19 #define SPI_MODE_2 (SPI_CPOL|0)
20 #define SPI_MODE_3 (SPI_CPOL|SPI_CPHA)
21 #define SPI_CS_HIGH BIT(2) /* CS active high */
22 #define SPI_LSB_FIRST BIT(3) /* per-word bits-on-wire */
23 #define SPI_3WIRE BIT(4) /* SI/SO signals shared */
24 #define SPI_LOOP BIT(5) /* loopback mode */
25 #define SPI_SLAVE BIT(6) /* slave mode */
26 #define SPI_PREAMBLE BIT(7) /* Skip preamble bytes */
27 #define SPI_TX_BYTE BIT(8) /* transmit with 1 wire byte */
28 #define SPI_TX_DUAL BIT(9) /* transmit with 2 wires */
29 #define SPI_TX_QUAD BIT(10) /* transmit with 4 wires */
30 #define SPI_RX_SLOW BIT(11) /* receive with 1 wire slow */
31 #define SPI_RX_DUAL BIT(12) /* receive with 2 wires */
32 #define SPI_RX_QUAD BIT(13) /* receive with 4 wires */
34 /* Header byte that marks the start of the message */
35 #define SPI_PREAMBLE_END_BYTE 0xec
37 #define SPI_DEFAULT_WORDLEN 8
40 /* TODO(sjg@chromium.org): Remove this and use max_hz from struct spi_slave */
46 * struct dm_spi_platdata - platform data for all SPI slaves
48 * This describes a SPI slave, a child device of the SPI bus. To obtain this
49 * struct from a spi_slave, use dev_get_parent_platdata(dev) or
50 * dev_get_parent_platdata(slave->dev).
52 * This data is immuatable. Each time the device is probed, @max_hz and @mode
53 * will be copied to struct spi_slave.
55 * @cs: Chip select number (0..n-1)
56 * @max_hz: Maximum bus speed that this slave can tolerate
57 * @mode: SPI mode to use for this device (see SPI mode flags)
59 struct dm_spi_slave_platdata {
65 #endif /* CONFIG_DM_SPI */
68 * struct spi_slave - Representation of a SPI slave
70 * For driver model this is the per-child data used by the SPI bus. It can
71 * be accessed using dev_get_parent_priv() on the slave device. The SPI uclass
72 * sets uip per_child_auto_alloc_size to sizeof(struct spi_slave), and the
73 * driver should not override it. Two platform data fields (max_hz and mode)
74 * are copied into this structure to provide an initial value. This allows
75 * them to be changed, since we should never change platform data in drivers.
77 * If not using driver model, drivers are expected to extend this with
78 * controller-specific data.
80 * @dev: SPI slave device
81 * @max_hz: Maximum speed for this slave
82 * @speed: Current bus speed. This is 0 until the bus is first
84 * @bus: ID of the bus that the slave is attached to. For
85 * driver model this is the sequence number of the SPI
86 * bus (bus->seq) so does not need to be stored
87 * @cs: ID of the chip select connected to the slave.
88 * @mode: SPI mode to use for this slave (see SPI mode flags)
89 * @wordlen: Size of SPI word in number of bits
90 * @max_read_size: If non-zero, the maximum number of bytes which can
92 * @max_write_size: If non-zero, the maximum number of bytes which can
94 * @memory_map: Address of read-only SPI flash access.
95 * @flags: Indication of SPI flags.
99 struct udevice *dev; /* struct spi_slave is dev->parentdata */
107 unsigned int wordlen;
108 unsigned int max_read_size;
109 unsigned int max_write_size;
113 #define SPI_XFER_BEGIN BIT(0) /* Assert CS before transfer */
114 #define SPI_XFER_END BIT(1) /* Deassert CS after transfer */
115 #define SPI_XFER_ONCE (SPI_XFER_BEGIN | SPI_XFER_END)
116 #define SPI_XFER_MMAP BIT(2) /* Memory Mapped start */
117 #define SPI_XFER_MMAP_END BIT(3) /* Memory Mapped End */
121 * spi_do_alloc_slave - Allocate a new SPI slave (internal)
123 * Allocate and zero all fields in the spi slave, and set the bus/chip
124 * select. Use the helper macro spi_alloc_slave() to call this.
126 * @offset: Offset of struct spi_slave within slave structure.
127 * @size: Size of slave structure.
128 * @bus: Bus ID of the slave chip.
129 * @cs: Chip select ID of the slave chip on the specified bus.
131 void *spi_do_alloc_slave(int offset, int size, unsigned int bus,
135 * spi_alloc_slave - Allocate a new SPI slave
137 * Allocate and zero all fields in the spi slave, and set the bus/chip
140 * @_struct: Name of structure to allocate (e.g. struct tegra_spi).
141 * This structure must contain a member 'struct spi_slave *slave'.
142 * @bus: Bus ID of the slave chip.
143 * @cs: Chip select ID of the slave chip on the specified bus.
145 #define spi_alloc_slave(_struct, bus, cs) \
146 spi_do_alloc_slave(offsetof(_struct, slave), \
147 sizeof(_struct), bus, cs)
150 * spi_alloc_slave_base - Allocate a new SPI slave with no private data
152 * Allocate and zero all fields in the spi slave, and set the bus/chip
155 * @bus: Bus ID of the slave chip.
156 * @cs: Chip select ID of the slave chip on the specified bus.
158 #define spi_alloc_slave_base(bus, cs) \
159 spi_do_alloc_slave(0, sizeof(struct spi_slave), bus, cs)
162 * Set up communications parameters for a SPI slave.
164 * This must be called once for each slave. Note that this function
165 * usually doesn't touch any actual hardware, it only initializes the
166 * contents of spi_slave so that the hardware can be easily
169 * @bus: Bus ID of the slave chip.
170 * @cs: Chip select ID of the slave chip on the specified bus.
171 * @max_hz: Maximum SCK rate in Hz.
172 * @mode: Clock polarity, clock phase and other parameters.
174 * Returns: A spi_slave reference that can be used in subsequent SPI
175 * calls, or NULL if one or more of the parameters are not supported.
177 struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
178 unsigned int max_hz, unsigned int mode);
181 * Free any memory associated with a SPI slave.
183 * @slave: The SPI slave
185 void spi_free_slave(struct spi_slave *slave);
188 * Claim the bus and prepare it for communication with a given slave.
190 * This must be called before doing any transfers with a SPI slave. It
191 * will enable and initialize any SPI hardware as necessary, and make
192 * sure that the SCK line is in the correct idle state. It is not
193 * allowed to claim the same bus for several slaves without releasing
194 * the bus in between.
196 * @slave: The SPI slave
198 * Returns: 0 if the bus was claimed successfully, or a negative value
201 int spi_claim_bus(struct spi_slave *slave);
204 * Release the SPI bus
206 * This must be called once for every call to spi_claim_bus() after
207 * all transfers have finished. It may disable any SPI hardware as
210 * @slave: The SPI slave
212 void spi_release_bus(struct spi_slave *slave);
215 * Set the word length for SPI transactions
217 * Set the word length (number of bits per word) for SPI transactions.
219 * @slave: The SPI slave
220 * @wordlen: The number of bits in a word
222 * Returns: 0 on success, -1 on failure.
224 int spi_set_wordlen(struct spi_slave *slave, unsigned int wordlen);
229 * This writes "bitlen" bits out the SPI MOSI port and simultaneously clocks
230 * "bitlen" bits in the SPI MISO port. That's just the way SPI works.
232 * The source of the outgoing bits is the "dout" parameter and the
233 * destination of the input bits is the "din" parameter. Note that "dout"
234 * and "din" can point to the same memory location, in which case the
235 * input data overwrites the output data (since both are buffered by
236 * temporary variables, this is OK).
238 * spi_xfer() interface:
239 * @slave: The SPI slave which will be sending/receiving the data.
240 * @bitlen: How many bits to write and read.
241 * @dout: Pointer to a string of bits to send out. The bits are
242 * held in a byte array and are sent MSB first.
243 * @din: Pointer to a string of bits that will be filled in.
244 * @flags: A bitwise combination of SPI_XFER_* flags.
246 * Returns: 0 on success, not 0 on failure
248 int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
249 void *din, unsigned long flags);
252 * spi_write_then_read - SPI synchronous write followed by read
254 * This performs a half duplex transaction in which the first transaction
255 * is to send the opcode and if the length of buf is non-zero then it start
256 * the second transaction as tx or rx based on the need from respective slave.
258 * @slave: The SPI slave device with which opcode/data will be exchanged
259 * @opcode: opcode used for specific transfer
260 * @n_opcode: size of opcode, in bytes
261 * @txbuf: buffer into which data to be written
262 * @rxbuf: buffer into which data will be read
263 * @n_buf: size of buf (whether it's [tx|rx]buf), in bytes
265 * Returns: 0 on success, not 0 on failure
267 int spi_write_then_read(struct spi_slave *slave, const u8 *opcode,
268 size_t n_opcode, const u8 *txbuf, u8 *rxbuf,
271 /* Copy memory mapped data */
272 void spi_flash_copy_mmap(void *data, void *offset, size_t len);
275 * Determine if a SPI chipselect is valid.
276 * This function is provided by the board if the low-level SPI driver
277 * needs it to determine if a given chipselect is actually valid.
279 * Returns: 1 if bus:cs identifies a valid chip on this board, 0
282 int spi_cs_is_valid(unsigned int bus, unsigned int cs);
284 #ifndef CONFIG_DM_SPI
286 * Activate a SPI chipselect.
287 * This function is provided by the board code when using a driver
288 * that can't control its chipselects automatically (e.g.
289 * common/soft_spi.c). When called, it should activate the chip select
290 * to the device identified by "slave".
292 void spi_cs_activate(struct spi_slave *slave);
295 * Deactivate a SPI chipselect.
296 * This function is provided by the board code when using a driver
297 * that can't control its chipselects automatically (e.g.
298 * common/soft_spi.c). When called, it should deactivate the chip
299 * select to the device identified by "slave".
301 void spi_cs_deactivate(struct spi_slave *slave);
304 * Set transfer speed.
305 * This sets a new speed to be applied for next spi_xfer().
306 * @slave: The SPI slave
307 * @hz: The transfer speed
309 void spi_set_speed(struct spi_slave *slave, uint hz);
313 * Write 8 bits, then read 8 bits.
314 * @slave: The SPI slave we're communicating with
315 * @byte: Byte to be written
317 * Returns: The value that was read, or a negative value on error.
319 * TODO: This function probably shouldn't be inlined.
321 static inline int spi_w8r8(struct spi_slave *slave, unsigned char byte)
323 unsigned char dout[2];
324 unsigned char din[2];
330 ret = spi_xfer(slave, 16, dout, din, SPI_XFER_BEGIN | SPI_XFER_END);
331 return ret < 0 ? ret : din[1];
337 * struct spi_cs_info - Information about a bus chip select
339 * @dev: Connected device, or NULL if none
346 * struct struct dm_spi_ops - Driver model SPI operations
348 * The uclass interface is implemented by all SPI devices which use
353 * Claim the bus and prepare it for communication.
355 * The device provided is the slave device. It's parent controller
356 * will be used to provide the communication.
358 * This must be called before doing any transfers with a SPI slave. It
359 * will enable and initialize any SPI hardware as necessary, and make
360 * sure that the SCK line is in the correct idle state. It is not
361 * allowed to claim the same bus for several slaves without releasing
362 * the bus in between.
364 * @dev: The SPI slave
366 * Returns: 0 if the bus was claimed successfully, or a negative value
369 int (*claim_bus)(struct udevice *dev);
372 * Release the SPI bus
374 * This must be called once for every call to spi_claim_bus() after
375 * all transfers have finished. It may disable any SPI hardware as
378 * @dev: The SPI slave
380 int (*release_bus)(struct udevice *dev);
383 * Set the word length for SPI transactions
385 * Set the word length (number of bits per word) for SPI transactions.
387 * @bus: The SPI slave
388 * @wordlen: The number of bits in a word
390 * Returns: 0 on success, -ve on failure.
392 int (*set_wordlen)(struct udevice *dev, unsigned int wordlen);
397 * This writes "bitlen" bits out the SPI MOSI port and simultaneously
398 * clocks "bitlen" bits in the SPI MISO port. That's just the way SPI
401 * The source of the outgoing bits is the "dout" parameter and the
402 * destination of the input bits is the "din" parameter. Note that
403 * "dout" and "din" can point to the same memory location, in which
404 * case the input data overwrites the output data (since both are
405 * buffered by temporary variables, this is OK).
407 * spi_xfer() interface:
408 * @dev: The slave device to communicate with
409 * @bitlen: How many bits to write and read.
410 * @dout: Pointer to a string of bits to send out. The bits are
411 * held in a byte array and are sent MSB first.
412 * @din: Pointer to a string of bits that will be filled in.
413 * @flags: A bitwise combination of SPI_XFER_* flags.
415 * Returns: 0 on success, not -1 on failure
417 int (*xfer)(struct udevice *dev, unsigned int bitlen, const void *dout,
418 void *din, unsigned long flags);
421 * Optimized handlers for SPI memory-like operations.
423 * Optimized/dedicated operations for interactions with SPI memory. This
424 * field is optional and should only be implemented if the controller
425 * has native support for memory like operations.
427 const struct spi_controller_mem_ops *mem_ops;
430 * Set transfer speed.
431 * This sets a new speed to be applied for next spi_xfer().
433 * @hz: The transfer speed
434 * @return 0 if OK, -ve on error
436 int (*set_speed)(struct udevice *bus, uint hz);
439 * Set the SPI mode/flags
441 * It is unclear if we want to set speed and mode together instead
445 * @mode: Requested SPI mode (SPI_... flags)
446 * @return 0 if OK, -ve on error
448 int (*set_mode)(struct udevice *bus, uint mode);
451 * Get information on a chip select
453 * This is only called when the SPI uclass does not know about a
454 * chip select, i.e. it has no attached device. It gives the driver
455 * a chance to allow activity on that chip select even so.
458 * @cs: The chip select (0..n-1)
459 * @info: Returns information about the chip select, if valid.
460 * On entry info->dev is NULL
461 * @return 0 if OK (and @info is set up), -ENODEV if the chip select
462 * is invalid, other -ve value on error
464 int (*cs_info)(struct udevice *bus, uint cs, struct spi_cs_info *info);
467 struct dm_spi_emul_ops {
471 * This writes "bitlen" bits out the SPI MOSI port and simultaneously
472 * clocks "bitlen" bits in the SPI MISO port. That's just the way SPI
473 * works. Here the device is a slave.
475 * The source of the outgoing bits is the "dout" parameter and the
476 * destination of the input bits is the "din" parameter. Note that
477 * "dout" and "din" can point to the same memory location, in which
478 * case the input data overwrites the output data (since both are
479 * buffered by temporary variables, this is OK).
481 * spi_xfer() interface:
482 * @slave: The SPI slave which will be sending/receiving the data.
483 * @bitlen: How many bits to write and read.
484 * @dout: Pointer to a string of bits sent to the device. The
485 * bits are held in a byte array and are sent MSB first.
486 * @din: Pointer to a string of bits that will be sent back to
488 * @flags: A bitwise combination of SPI_XFER_* flags.
490 * Returns: 0 on success, not -1 on failure
492 int (*xfer)(struct udevice *slave, unsigned int bitlen,
493 const void *dout, void *din, unsigned long flags);
497 * spi_find_bus_and_cs() - Find bus and slave devices by number
499 * Given a bus number and chip select, this finds the corresponding bus
500 * device and slave device. Neither device is activated by this function,
501 * although they may have been activated previously.
503 * @busnum: SPI bus number
504 * @cs: Chip select to look for
505 * @busp: Returns bus device
506 * @devp: Return slave device
507 * @return 0 if found, -ENODEV on error
509 int spi_find_bus_and_cs(int busnum, int cs, struct udevice **busp,
510 struct udevice **devp);
513 * spi_get_bus_and_cs() - Find and activate bus and slave devices by number
515 * Given a bus number and chip select, this finds the corresponding bus
516 * device and slave device.
518 * If no such slave exists, and drv_name is not NULL, then a new slave device
519 * is automatically bound on this chip select with requested speed and mode.
521 * Ths new slave device is probed ready for use with the speed and mode
522 * from platdata when available or the requested values.
524 * @busnum: SPI bus number
525 * @cs: Chip select to look for
526 * @speed: SPI speed to use for this slave when not available in platdata
527 * @mode: SPI mode to use for this slave when not available in platdata
528 * @drv_name: Name of driver to attach to this chip select
529 * @dev_name: Name of the new device thus created
530 * @busp: Returns bus device
531 * @devp: Return slave device
532 * @return 0 if found, -ve on error
534 int spi_get_bus_and_cs(int busnum, int cs, int speed, int mode,
535 const char *drv_name, const char *dev_name,
536 struct udevice **busp, struct spi_slave **devp);
539 * spi_chip_select() - Get the chip select for a slave
541 * @return the chip select this slave is attached to
543 int spi_chip_select(struct udevice *slave);
546 * spi_find_chip_select() - Find the slave attached to chip select
548 * @bus: SPI bus to search
549 * @cs: Chip select to look for
550 * @devp: Returns the slave device if found
551 * @return 0 if found, -ENODEV on error
553 int spi_find_chip_select(struct udevice *bus, int cs, struct udevice **devp);
556 * spi_slave_ofdata_to_platdata() - decode standard SPI platform data
558 * This decodes the speed and mode for a slave from a device tree node
560 * @blob: Device tree blob
561 * @node: Node offset to read from
562 * @plat: Place to put the decoded information
564 int spi_slave_ofdata_to_platdata(struct udevice *dev,
565 struct dm_spi_slave_platdata *plat);
568 * spi_cs_info() - Check information on a chip select
570 * This checks a particular chip select on a bus to see if it has a device
571 * attached, or is even valid.
574 * @cs: The chip select (0..n-1)
575 * @info: Returns information about the chip select, if valid
576 * @return 0 if OK (and @info is set up), -ENODEV if the chip select
577 * is invalid, other -ve value on error
579 int spi_cs_info(struct udevice *bus, uint cs, struct spi_cs_info *info);
581 struct sandbox_state;
584 * sandbox_spi_get_emul() - get an emulator for a SPI slave
586 * This provides a way to attach an emulated SPI device to a particular SPI
587 * slave, so that xfer() operations on the slave will be handled by the
588 * emulator. If a emulator already exists on that chip select it is returned.
589 * Otherwise one is created.
591 * @state: Sandbox state
592 * @bus: SPI bus requesting the emulator
593 * @slave: SPI slave device requesting the emulator
594 * @emuip: Returns pointer to emulator
595 * @return 0 if OK, -ve on error
597 int sandbox_spi_get_emul(struct sandbox_state *state,
598 struct udevice *bus, struct udevice *slave,
599 struct udevice **emulp);
602 * Claim the bus and prepare it for communication with a given slave.
604 * This must be called before doing any transfers with a SPI slave. It
605 * will enable and initialize any SPI hardware as necessary, and make
606 * sure that the SCK line is in the correct idle state. It is not
607 * allowed to claim the same bus for several slaves without releasing
608 * the bus in between.
610 * @dev: The SPI slave device
612 * Returns: 0 if the bus was claimed successfully, or a negative value
615 int dm_spi_claim_bus(struct udevice *dev);
618 * Release the SPI bus
620 * This must be called once for every call to dm_spi_claim_bus() after
621 * all transfers have finished. It may disable any SPI hardware as
624 * @slave: The SPI slave device
626 void dm_spi_release_bus(struct udevice *dev);
631 * This writes "bitlen" bits out the SPI MOSI port and simultaneously clocks
632 * "bitlen" bits in the SPI MISO port. That's just the way SPI works.
634 * The source of the outgoing bits is the "dout" parameter and the
635 * destination of the input bits is the "din" parameter. Note that "dout"
636 * and "din" can point to the same memory location, in which case the
637 * input data overwrites the output data (since both are buffered by
638 * temporary variables, this is OK).
640 * dm_spi_xfer() interface:
641 * @dev: The SPI slave device which will be sending/receiving the data.
642 * @bitlen: How many bits to write and read.
643 * @dout: Pointer to a string of bits to send out. The bits are
644 * held in a byte array and are sent MSB first.
645 * @din: Pointer to a string of bits that will be filled in.
646 * @flags: A bitwise combination of SPI_XFER_* flags.
648 * Returns: 0 on success, not 0 on failure
650 int dm_spi_xfer(struct udevice *dev, unsigned int bitlen,
651 const void *dout, void *din, unsigned long flags);
653 /* Access the operations for a SPI device */
654 #define spi_get_ops(dev) ((struct dm_spi_ops *)(dev)->driver->ops)
655 #define spi_emul_get_ops(dev) ((struct dm_spi_emul_ops *)(dev)->driver->ops)
656 #endif /* CONFIG_DM_SPI */