spi.h 23 KB

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  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. #ifndef _SPI_H_
  9. #define _SPI_H_
  10. #include <common.h>
  11. #include <linux/bitops.h>
  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. #define SPI_TX_OCTAL BIT(14) /* transmit with 8 wires */
  32. #define SPI_RX_OCTAL BIT(15) /* receive with 8 wires */
  33. /* Header byte that marks the start of the message */
  34. #define SPI_PREAMBLE_END_BYTE 0xec
  35. #define SPI_DEFAULT_WORDLEN 8
  36. /* TODO(sjg@chromium.org): Remove this and use max_hz from struct spi_slave */
  37. struct dm_spi_bus {
  38. uint max_hz;
  39. };
  40. /**
  41. * struct dm_spi_platdata - platform data for all SPI slaves
  42. *
  43. * This describes a SPI slave, a child device of the SPI bus. To obtain this
  44. * struct from a spi_slave, use dev_get_parent_platdata(dev) or
  45. * dev_get_parent_platdata(slave->dev).
  46. *
  47. * This data is immuatable. Each time the device is probed, @max_hz and @mode
  48. * will be copied to struct spi_slave.
  49. *
  50. * @cs: Chip select number (0..n-1)
  51. * @max_hz: Maximum bus speed that this slave can tolerate
  52. * @mode: SPI mode to use for this device (see SPI mode flags)
  53. */
  54. struct dm_spi_slave_platdata {
  55. unsigned int cs;
  56. uint max_hz;
  57. uint mode;
  58. };
  59. /**
  60. * enum spi_clock_phase - indicates the clock phase to use for SPI (CPHA)
  61. *
  62. * @SPI_CLOCK_PHASE_FIRST: Data sampled on the first phase
  63. * @SPI_CLOCK_PHASE_SECOND: Data sampled on the second phase
  64. */
  65. enum spi_clock_phase {
  66. SPI_CLOCK_PHASE_FIRST,
  67. SPI_CLOCK_PHASE_SECOND,
  68. };
  69. /**
  70. * enum spi_wire_mode - indicates the number of wires used for SPI
  71. *
  72. * @SPI_4_WIRE_MODE: Normal bidirectional mode with MOSI and MISO
  73. * @SPI_3_WIRE_MODE: Unidirectional version with a single data line SISO
  74. */
  75. enum spi_wire_mode {
  76. SPI_4_WIRE_MODE,
  77. SPI_3_WIRE_MODE,
  78. };
  79. /**
  80. * enum spi_polarity - indicates the polarity of the SPI bus (CPOL)
  81. *
  82. * @SPI_POLARITY_LOW: Clock is low in idle state
  83. * @SPI_POLARITY_HIGH: Clock is high in idle state
  84. */
  85. enum spi_polarity {
  86. SPI_POLARITY_LOW,
  87. SPI_POLARITY_HIGH,
  88. };
  89. /**
  90. * struct spi_slave - Representation of a SPI slave
  91. *
  92. * For driver model this is the per-child data used by the SPI bus. It can
  93. * be accessed using dev_get_parent_priv() on the slave device. The SPI uclass
  94. * sets uip per_child_auto_alloc_size to sizeof(struct spi_slave), and the
  95. * driver should not override it. Two platform data fields (max_hz and mode)
  96. * are copied into this structure to provide an initial value. This allows
  97. * them to be changed, since we should never change platform data in drivers.
  98. *
  99. * If not using driver model, drivers are expected to extend this with
  100. * controller-specific data.
  101. *
  102. * @dev: SPI slave device
  103. * @max_hz: Maximum speed for this slave
  104. * @speed: Current bus speed. This is 0 until the bus is first
  105. * claimed.
  106. * @bus: ID of the bus that the slave is attached to. For
  107. * driver model this is the sequence number of the SPI
  108. * bus (bus->seq) so does not need to be stored
  109. * @cs: ID of the chip select connected to the slave.
  110. * @mode: SPI mode to use for this slave (see SPI mode flags)
  111. * @wordlen: Size of SPI word in number of bits
  112. * @max_read_size: If non-zero, the maximum number of bytes which can
  113. * be read at once.
  114. * @max_write_size: If non-zero, the maximum number of bytes which can
  115. * be written at once.
  116. * @memory_map: Address of read-only SPI flash access.
  117. * @flags: Indication of SPI flags.
  118. */
  119. struct spi_slave {
  120. #if CONFIG_IS_ENABLED(DM_SPI)
  121. struct udevice *dev; /* struct spi_slave is dev->parentdata */
  122. uint max_hz;
  123. uint speed;
  124. #else
  125. unsigned int bus;
  126. unsigned int cs;
  127. #endif
  128. uint mode;
  129. unsigned int wordlen;
  130. unsigned int max_read_size;
  131. unsigned int max_write_size;
  132. void *memory_map;
  133. u8 flags;
  134. #define SPI_XFER_BEGIN BIT(0) /* Assert CS before transfer */
  135. #define SPI_XFER_END BIT(1) /* Deassert CS after transfer */
  136. #define SPI_XFER_ONCE (SPI_XFER_BEGIN | SPI_XFER_END)
  137. #define SPI_XFER_MMAP BIT(2) /* Memory Mapped start */
  138. #define SPI_XFER_MMAP_END BIT(3) /* Memory Mapped End */
  139. };
  140. /**
  141. * spi_do_alloc_slave - Allocate a new SPI slave (internal)
  142. *
  143. * Allocate and zero all fields in the spi slave, and set the bus/chip
  144. * select. Use the helper macro spi_alloc_slave() to call this.
  145. *
  146. * @offset: Offset of struct spi_slave within slave structure.
  147. * @size: Size of slave structure.
  148. * @bus: Bus ID of the slave chip.
  149. * @cs: Chip select ID of the slave chip on the specified bus.
  150. */
  151. void *spi_do_alloc_slave(int offset, int size, unsigned int bus,
  152. unsigned int cs);
  153. /**
  154. * spi_alloc_slave - Allocate a new SPI slave
  155. *
  156. * Allocate and zero all fields in the spi slave, and set the bus/chip
  157. * select.
  158. *
  159. * @_struct: Name of structure to allocate (e.g. struct tegra_spi).
  160. * This structure must contain a member 'struct spi_slave *slave'.
  161. * @bus: Bus ID of the slave chip.
  162. * @cs: Chip select ID of the slave chip on the specified bus.
  163. */
  164. #define spi_alloc_slave(_struct, bus, cs) \
  165. spi_do_alloc_slave(offsetof(_struct, slave), \
  166. sizeof(_struct), bus, cs)
  167. /**
  168. * spi_alloc_slave_base - Allocate a new SPI slave with no private data
  169. *
  170. * Allocate and zero all fields in the spi slave, and set the bus/chip
  171. * select.
  172. *
  173. * @bus: Bus ID of the slave chip.
  174. * @cs: Chip select ID of the slave chip on the specified bus.
  175. */
  176. #define spi_alloc_slave_base(bus, cs) \
  177. spi_do_alloc_slave(0, sizeof(struct spi_slave), bus, cs)
  178. /**
  179. * Set up communications parameters for a SPI slave.
  180. *
  181. * This must be called once for each slave. Note that this function
  182. * usually doesn't touch any actual hardware, it only initializes the
  183. * contents of spi_slave so that the hardware can be easily
  184. * initialized later.
  185. *
  186. * @bus: Bus ID of the slave chip.
  187. * @cs: Chip select ID of the slave chip on the specified bus.
  188. * @max_hz: Maximum SCK rate in Hz.
  189. * @mode: Clock polarity, clock phase and other parameters.
  190. *
  191. * Returns: A spi_slave reference that can be used in subsequent SPI
  192. * calls, or NULL if one or more of the parameters are not supported.
  193. */
  194. struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
  195. unsigned int max_hz, unsigned int mode);
  196. /**
  197. * Free any memory associated with a SPI slave.
  198. *
  199. * @slave: The SPI slave
  200. */
  201. void spi_free_slave(struct spi_slave *slave);
  202. /**
  203. * Claim the bus and prepare it for communication with a given slave.
  204. *
  205. * This must be called before doing any transfers with a SPI slave. It
  206. * will enable and initialize any SPI hardware as necessary, and make
  207. * sure that the SCK line is in the correct idle state. It is not
  208. * allowed to claim the same bus for several slaves without releasing
  209. * the bus in between.
  210. *
  211. * @slave: The SPI slave
  212. *
  213. * Returns: 0 if the bus was claimed successfully, or a negative value
  214. * if it wasn't.
  215. */
  216. int spi_claim_bus(struct spi_slave *slave);
  217. /**
  218. * Release the SPI bus
  219. *
  220. * This must be called once for every call to spi_claim_bus() after
  221. * all transfers have finished. It may disable any SPI hardware as
  222. * appropriate.
  223. *
  224. * @slave: The SPI slave
  225. */
  226. void spi_release_bus(struct spi_slave *slave);
  227. /**
  228. * Set the word length for SPI transactions
  229. *
  230. * Set the word length (number of bits per word) for SPI transactions.
  231. *
  232. * @slave: The SPI slave
  233. * @wordlen: The number of bits in a word
  234. *
  235. * Returns: 0 on success, -1 on failure.
  236. */
  237. int spi_set_wordlen(struct spi_slave *slave, unsigned int wordlen);
  238. /**
  239. * SPI transfer (optional if mem_ops is used)
  240. *
  241. * This writes "bitlen" bits out the SPI MOSI port and simultaneously clocks
  242. * "bitlen" bits in the SPI MISO port. That's just the way SPI works.
  243. *
  244. * The source of the outgoing bits is the "dout" parameter and the
  245. * destination of the input bits is the "din" parameter. Note that "dout"
  246. * and "din" can point to the same memory location, in which case the
  247. * input data overwrites the output data (since both are buffered by
  248. * temporary variables, this is OK).
  249. *
  250. * spi_xfer() interface:
  251. * @slave: The SPI slave which will be sending/receiving the data.
  252. * @bitlen: How many bits to write and read.
  253. * @dout: Pointer to a string of bits to send out. The bits are
  254. * held in a byte array and are sent MSB first.
  255. * @din: Pointer to a string of bits that will be filled in.
  256. * @flags: A bitwise combination of SPI_XFER_* flags.
  257. *
  258. * Returns: 0 on success, not 0 on failure
  259. */
  260. int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
  261. void *din, unsigned long flags);
  262. /**
  263. * spi_write_then_read - SPI synchronous write followed by read
  264. *
  265. * This performs a half duplex transaction in which the first transaction
  266. * is to send the opcode and if the length of buf is non-zero then it start
  267. * the second transaction as tx or rx based on the need from respective slave.
  268. *
  269. * @slave: The SPI slave device with which opcode/data will be exchanged
  270. * @opcode: opcode used for specific transfer
  271. * @n_opcode: size of opcode, in bytes
  272. * @txbuf: buffer into which data to be written
  273. * @rxbuf: buffer into which data will be read
  274. * @n_buf: size of buf (whether it's [tx|rx]buf), in bytes
  275. *
  276. * Returns: 0 on success, not 0 on failure
  277. */
  278. int spi_write_then_read(struct spi_slave *slave, const u8 *opcode,
  279. size_t n_opcode, const u8 *txbuf, u8 *rxbuf,
  280. size_t n_buf);
  281. /* Copy memory mapped data */
  282. void spi_flash_copy_mmap(void *data, void *offset, size_t len);
  283. /**
  284. * Determine if a SPI chipselect is valid.
  285. * This function is provided by the board if the low-level SPI driver
  286. * needs it to determine if a given chipselect is actually valid.
  287. *
  288. * Returns: 1 if bus:cs identifies a valid chip on this board, 0
  289. * otherwise.
  290. */
  291. int spi_cs_is_valid(unsigned int bus, unsigned int cs);
  292. /*
  293. * These names are used in several drivers and these declarations will be
  294. * removed soon as part of the SPI DM migration. Drop them if driver model is
  295. * enabled for SPI.
  296. */
  297. #if !CONFIG_IS_ENABLED(DM_SPI)
  298. /**
  299. * Activate 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 activate the chip select
  303. * to the device identified by "slave".
  304. */
  305. void spi_cs_activate(struct spi_slave *slave);
  306. /**
  307. * Deactivate a SPI chipselect.
  308. * This function is provided by the board code when using a driver
  309. * that can't control its chipselects automatically (e.g.
  310. * common/soft_spi.c). When called, it should deactivate the chip
  311. * select to the device identified by "slave".
  312. */
  313. void spi_cs_deactivate(struct spi_slave *slave);
  314. #endif
  315. /**
  316. * Set transfer speed.
  317. * This sets a new speed to be applied for next spi_xfer().
  318. * @slave: The SPI slave
  319. * @hz: The transfer speed
  320. */
  321. void spi_set_speed(struct spi_slave *slave, uint hz);
  322. /**
  323. * Write 8 bits, then read 8 bits.
  324. * @slave: The SPI slave we're communicating with
  325. * @byte: Byte to be written
  326. *
  327. * Returns: The value that was read, or a negative value on error.
  328. *
  329. * TODO: This function probably shouldn't be inlined.
  330. */
  331. static inline int spi_w8r8(struct spi_slave *slave, unsigned char byte)
  332. {
  333. unsigned char dout[2];
  334. unsigned char din[2];
  335. int ret;
  336. dout[0] = byte;
  337. dout[1] = 0;
  338. ret = spi_xfer(slave, 16, dout, din, SPI_XFER_BEGIN | SPI_XFER_END);
  339. return ret < 0 ? ret : din[1];
  340. }
  341. /**
  342. * struct spi_cs_info - Information about a bus chip select
  343. *
  344. * @dev: Connected device, or NULL if none
  345. */
  346. struct spi_cs_info {
  347. struct udevice *dev;
  348. };
  349. /**
  350. * struct struct dm_spi_ops - Driver model SPI operations
  351. *
  352. * The uclass interface is implemented by all SPI devices which use
  353. * driver model.
  354. */
  355. struct dm_spi_ops {
  356. /**
  357. * Claim the bus and prepare it for communication.
  358. *
  359. * The device provided is the slave device. It's parent controller
  360. * will be used to provide the communication.
  361. *
  362. * This must be called before doing any transfers with a SPI slave. It
  363. * will enable and initialize any SPI hardware as necessary, and make
  364. * sure that the SCK line is in the correct idle state. It is not
  365. * allowed to claim the same bus for several slaves without releasing
  366. * the bus in between.
  367. *
  368. * @dev: The SPI slave
  369. *
  370. * Returns: 0 if the bus was claimed successfully, or a negative value
  371. * if it wasn't.
  372. */
  373. int (*claim_bus)(struct udevice *dev);
  374. /**
  375. * Release the SPI bus
  376. *
  377. * This must be called once for every call to spi_claim_bus() after
  378. * all transfers have finished. It may disable any SPI hardware as
  379. * appropriate.
  380. *
  381. * @dev: The SPI slave
  382. */
  383. int (*release_bus)(struct udevice *dev);
  384. /**
  385. * Set the word length for SPI transactions
  386. *
  387. * Set the word length (number of bits per word) for SPI transactions.
  388. *
  389. * @bus: The SPI slave
  390. * @wordlen: The number of bits in a word
  391. *
  392. * Returns: 0 on success, -ve on failure.
  393. */
  394. int (*set_wordlen)(struct udevice *dev, unsigned int wordlen);
  395. /**
  396. * SPI transfer
  397. *
  398. * This writes "bitlen" bits out the SPI MOSI port and simultaneously
  399. * clocks "bitlen" bits in the SPI MISO port. That's just the way SPI
  400. * works.
  401. *
  402. * The source of the outgoing bits is the "dout" parameter and the
  403. * destination of the input bits is the "din" parameter. Note that
  404. * "dout" and "din" can point to the same memory location, in which
  405. * case the input data overwrites the output data (since both are
  406. * buffered by temporary variables, this is OK).
  407. *
  408. * spi_xfer() interface:
  409. * @dev: The slave device to communicate with
  410. * @bitlen: How many bits to write and read.
  411. * @dout: Pointer to a string of bits to send out. The bits are
  412. * held in a byte array and are sent MSB first.
  413. * @din: Pointer to a string of bits that will be filled in.
  414. * @flags: A bitwise combination of SPI_XFER_* flags.
  415. *
  416. * Returns: 0 on success, not -1 on failure
  417. */
  418. int (*xfer)(struct udevice *dev, unsigned int bitlen, const void *dout,
  419. void *din, unsigned long flags);
  420. /**
  421. * Optimized handlers for SPI memory-like operations.
  422. *
  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.
  426. */
  427. const struct spi_controller_mem_ops *mem_ops;
  428. /**
  429. * Set transfer speed.
  430. * This sets a new speed to be applied for next spi_xfer().
  431. * @bus: The SPI bus
  432. * @hz: The transfer speed
  433. * @return 0 if OK, -ve on error
  434. */
  435. int (*set_speed)(struct udevice *bus, uint hz);
  436. /**
  437. * Set the SPI mode/flags
  438. *
  439. * It is unclear if we want to set speed and mode together instead
  440. * of separately.
  441. *
  442. * @bus: The SPI bus
  443. * @mode: Requested SPI mode (SPI_... flags)
  444. * @return 0 if OK, -ve on error
  445. */
  446. int (*set_mode)(struct udevice *bus, uint mode);
  447. /**
  448. * Get information on a chip select
  449. *
  450. * This is only called when the SPI uclass does not know about a
  451. * chip select, i.e. it has no attached device. It gives the driver
  452. * a chance to allow activity on that chip select even so.
  453. *
  454. * @bus: The SPI bus
  455. * @cs: The chip select (0..n-1)
  456. * @info: Returns information about the chip select, if valid.
  457. * On entry info->dev is NULL
  458. * @return 0 if OK (and @info is set up), -EINVAL if the chip select
  459. * is invalid, other -ve value on error
  460. */
  461. int (*cs_info)(struct udevice *bus, uint cs, struct spi_cs_info *info);
  462. /**
  463. * get_mmap() - Get memory-mapped SPI
  464. *
  465. * @dev: The SPI flash slave device
  466. * @map_basep: Returns base memory address for mapped SPI
  467. * @map_sizep: Returns size of mapped SPI
  468. * @offsetp: Returns start offset of SPI flash where the map works
  469. * correctly (offsets before this are not visible)
  470. * @return 0 if OK, -EFAULT if memory mapping is not available
  471. */
  472. int (*get_mmap)(struct udevice *dev, ulong *map_basep,
  473. uint *map_sizep, uint *offsetp);
  474. };
  475. struct dm_spi_emul_ops {
  476. /**
  477. * SPI transfer
  478. *
  479. * This writes "bitlen" bits out the SPI MOSI port and simultaneously
  480. * clocks "bitlen" bits in the SPI MISO port. That's just the way SPI
  481. * works. Here the device is a slave.
  482. *
  483. * The source of the outgoing bits is the "dout" parameter and the
  484. * destination of the input bits is the "din" parameter. Note that
  485. * "dout" and "din" can point to the same memory location, in which
  486. * case the input data overwrites the output data (since both are
  487. * buffered by temporary variables, this is OK).
  488. *
  489. * spi_xfer() interface:
  490. * @slave: The SPI slave which will be sending/receiving the data.
  491. * @bitlen: How many bits to write and read.
  492. * @dout: Pointer to a string of bits sent to the device. The
  493. * bits are held in a byte array and are sent MSB first.
  494. * @din: Pointer to a string of bits that will be sent back to
  495. * the master.
  496. * @flags: A bitwise combination of SPI_XFER_* flags.
  497. *
  498. * Returns: 0 on success, not -1 on failure
  499. */
  500. int (*xfer)(struct udevice *slave, unsigned int bitlen,
  501. const void *dout, void *din, unsigned long flags);
  502. };
  503. /**
  504. * spi_find_bus_and_cs() - Find bus and slave devices by number
  505. *
  506. * Given a bus number and chip select, this finds the corresponding bus
  507. * device and slave device. Neither device is activated by this function,
  508. * although they may have been activated previously.
  509. *
  510. * @busnum: SPI bus number
  511. * @cs: Chip select to look for
  512. * @busp: Returns bus device
  513. * @devp: Return slave device
  514. * @return 0 if found, -ENODEV on error
  515. */
  516. int spi_find_bus_and_cs(int busnum, int cs, struct udevice **busp,
  517. struct udevice **devp);
  518. /**
  519. * spi_get_bus_and_cs() - Find and activate 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.
  523. *
  524. * If no such slave exists, and drv_name is not NULL, then a new slave device
  525. * is automatically bound on this chip select with requested speed and mode.
  526. *
  527. * Ths new slave device is probed ready for use with the speed and mode
  528. * from platdata when available or the requested values.
  529. *
  530. * @busnum: SPI bus number
  531. * @cs: Chip select to look for
  532. * @speed: SPI speed to use for this slave when not available in platdata
  533. * @mode: SPI mode to use for this slave when not available in platdata
  534. * @drv_name: Name of driver to attach to this chip select
  535. * @dev_name: Name of the new device thus created
  536. * @busp: Returns bus device
  537. * @devp: Return slave device
  538. * @return 0 if found, -ve on error
  539. */
  540. int spi_get_bus_and_cs(int busnum, int cs, int speed, int mode,
  541. const char *drv_name, const char *dev_name,
  542. struct udevice **busp, struct spi_slave **devp);
  543. /**
  544. * spi_chip_select() - Get the chip select for a slave
  545. *
  546. * @return the chip select this slave is attached to
  547. */
  548. int spi_chip_select(struct udevice *slave);
  549. /**
  550. * spi_find_chip_select() - Find the slave attached to chip select
  551. *
  552. * @bus: SPI bus to search
  553. * @cs: Chip select to look for
  554. * @devp: Returns the slave device if found
  555. * @return 0 if found, -EINVAL if cs is invalid, -ENODEV if no device attached,
  556. * other -ve value on error
  557. */
  558. int spi_find_chip_select(struct udevice *bus, int cs, struct udevice **devp);
  559. /**
  560. * spi_slave_ofdata_to_platdata() - decode standard SPI platform data
  561. *
  562. * This decodes the speed and mode for a slave from a device tree node
  563. *
  564. * @blob: Device tree blob
  565. * @node: Node offset to read from
  566. * @plat: Place to put the decoded information
  567. */
  568. int spi_slave_ofdata_to_platdata(struct udevice *dev,
  569. struct dm_spi_slave_platdata *plat);
  570. /**
  571. * spi_cs_info() - Check information on a chip select
  572. *
  573. * This checks a particular chip select on a bus to see if it has a device
  574. * attached, or is even valid.
  575. *
  576. * @bus: The SPI bus
  577. * @cs: The chip select (0..n-1)
  578. * @info: Returns information about the chip select, if valid
  579. * @return 0 if OK (and @info is set up), -ENODEV if the chip select
  580. * is invalid, other -ve value on error
  581. */
  582. int spi_cs_info(struct udevice *bus, uint cs, struct spi_cs_info *info);
  583. struct sandbox_state;
  584. /**
  585. * sandbox_spi_get_emul() - get an emulator for a SPI slave
  586. *
  587. * This provides a way to attach an emulated SPI device to a particular SPI
  588. * slave, so that xfer() operations on the slave will be handled by the
  589. * emulator. If a emulator already exists on that chip select it is returned.
  590. * Otherwise one is created.
  591. *
  592. * @state: Sandbox state
  593. * @bus: SPI bus requesting the emulator
  594. * @slave: SPI slave device requesting the emulator
  595. * @emuip: Returns pointer to emulator
  596. * @return 0 if OK, -ve on error
  597. */
  598. int sandbox_spi_get_emul(struct sandbox_state *state,
  599. struct udevice *bus, struct udevice *slave,
  600. struct udevice **emulp);
  601. /**
  602. * Claim the bus and prepare it for communication with a given slave.
  603. *
  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.
  609. *
  610. * @dev: The SPI slave device
  611. *
  612. * Returns: 0 if the bus was claimed successfully, or a negative value
  613. * if it wasn't.
  614. */
  615. int dm_spi_claim_bus(struct udevice *dev);
  616. /**
  617. * Release the SPI bus
  618. *
  619. * This must be called once for every call to dm_spi_claim_bus() after
  620. * all transfers have finished. It may disable any SPI hardware as
  621. * appropriate.
  622. *
  623. * @slave: The SPI slave device
  624. */
  625. void dm_spi_release_bus(struct udevice *dev);
  626. /**
  627. * SPI transfer
  628. *
  629. * This writes "bitlen" bits out the SPI MOSI port and simultaneously clocks
  630. * "bitlen" bits in the SPI MISO port. That's just the way SPI works.
  631. *
  632. * The source of the outgoing bits is the "dout" parameter and the
  633. * destination of the input bits is the "din" parameter. Note that "dout"
  634. * and "din" can point to the same memory location, in which case the
  635. * input data overwrites the output data (since both are buffered by
  636. * temporary variables, this is OK).
  637. *
  638. * dm_spi_xfer() interface:
  639. * @dev: The SPI slave device which will be sending/receiving the data.
  640. * @bitlen: How many bits to write and read.
  641. * @dout: Pointer to a string of bits to send out. The bits are
  642. * held in a byte array and are sent MSB first.
  643. * @din: Pointer to a string of bits that will be filled in.
  644. * @flags: A bitwise combination of SPI_XFER_* flags.
  645. *
  646. * Returns: 0 on success, not 0 on failure
  647. */
  648. int dm_spi_xfer(struct udevice *dev, unsigned int bitlen,
  649. const void *dout, void *din, unsigned long flags);
  650. /**
  651. * spi_get_mmap() - Get memory-mapped SPI
  652. *
  653. * @dev: SPI slave device to check
  654. * @map_basep: Returns base memory address for mapped SPI
  655. * @map_sizep: Returns size of mapped SPI
  656. * @offsetp: Returns start offset of SPI flash where the map works
  657. * correctly (offsets before this are not visible)
  658. * @return 0 if OK, -ENOSYS if no operation, -EFAULT if memory mapping is not
  659. * available
  660. */
  661. int dm_spi_get_mmap(struct udevice *dev, ulong *map_basep, uint *map_sizep,
  662. uint *offsetp);
  663. /* Access the operations for a SPI device */
  664. #define spi_get_ops(dev) ((struct dm_spi_ops *)(dev)->driver->ops)
  665. #define spi_emul_get_ops(dev) ((struct dm_spi_emul_ops *)(dev)->driver->ops)
  666. #endif /* _SPI_H_ */