spi.h 24 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 (1 = SPI_CLOCK_PHASE_SECOND) */
  14. #define SPI_CPOL BIT(1) /* clock polarity (1 = SPI_POLARITY_HIGH) */
  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. /**
  37. * struct dm_spi_bus - SPI bus info
  38. *
  39. * This contains information about a SPI bus. To obtain this structure, use
  40. * dev_get_uclass_priv(bus) where bus is the SPI bus udevice.
  41. *
  42. * @max_hz: Maximum speed that the bus can tolerate.
  43. * @speed: Current bus speed. This is 0 until the bus is first claimed.
  44. * @mode: Current bus mode. This is 0 until the bus is first claimed.
  45. *
  46. * TODO(sjg@chromium.org): Remove this and use max_hz from struct spi_slave.
  47. */
  48. struct dm_spi_bus {
  49. uint max_hz;
  50. uint speed;
  51. uint mode;
  52. };
  53. /**
  54. * struct dm_spi_plat - platform data for all SPI slaves
  55. *
  56. * This describes a SPI slave, a child device of the SPI bus. To obtain this
  57. * struct from a spi_slave, use dev_get_parent_plat(dev) or
  58. * dev_get_parent_plat(slave->dev).
  59. *
  60. * This data is immutable. Each time the device is probed, @max_hz and @mode
  61. * will be copied to struct spi_slave.
  62. *
  63. * @cs: Chip select number (0..n-1)
  64. * @max_hz: Maximum bus speed that this slave can tolerate
  65. * @mode: SPI mode to use for this device (see SPI mode flags)
  66. */
  67. struct dm_spi_slave_plat {
  68. unsigned int cs;
  69. uint max_hz;
  70. uint mode;
  71. };
  72. /**
  73. * enum spi_clock_phase - indicates the clock phase to use for SPI (CPHA)
  74. *
  75. * @SPI_CLOCK_PHASE_FIRST: Data sampled on the first phase
  76. * @SPI_CLOCK_PHASE_SECOND: Data sampled on the second phase
  77. */
  78. enum spi_clock_phase {
  79. SPI_CLOCK_PHASE_FIRST,
  80. SPI_CLOCK_PHASE_SECOND,
  81. };
  82. /**
  83. * enum spi_wire_mode - indicates the number of wires used for SPI
  84. *
  85. * @SPI_4_WIRE_MODE: Normal bidirectional mode with MOSI and MISO
  86. * @SPI_3_WIRE_MODE: Unidirectional version with a single data line SISO
  87. */
  88. enum spi_wire_mode {
  89. SPI_4_WIRE_MODE,
  90. SPI_3_WIRE_MODE,
  91. };
  92. /**
  93. * enum spi_polarity - indicates the polarity of the SPI bus (CPOL)
  94. *
  95. * @SPI_POLARITY_LOW: Clock is low in idle state
  96. * @SPI_POLARITY_HIGH: Clock is high in idle state
  97. */
  98. enum spi_polarity {
  99. SPI_POLARITY_LOW,
  100. SPI_POLARITY_HIGH,
  101. };
  102. /**
  103. * struct spi_slave - Representation of a SPI slave
  104. *
  105. * For driver model this is the per-child data used by the SPI bus. It can
  106. * be accessed using dev_get_parent_priv() on the slave device. The SPI uclass
  107. * sets up per_child_auto to sizeof(struct spi_slave), and the
  108. * driver should not override it. Two platform data fields (max_hz and mode)
  109. * are copied into this structure to provide an initial value. This allows
  110. * them to be changed, since we should never change platform data in drivers.
  111. *
  112. * If not using driver model, drivers are expected to extend this with
  113. * controller-specific data.
  114. *
  115. * @dev: SPI slave device
  116. * @max_hz: Maximum speed for this slave
  117. * @bus: ID of the bus that the slave is attached to. For
  118. * driver model this is the sequence number of the SPI
  119. * bus (dev_seq(bus)) so does not need to be stored
  120. * @cs: ID of the chip select connected to the slave.
  121. * @mode: SPI mode to use for this slave (see SPI mode flags)
  122. * @wordlen: Size of SPI word in number of bits
  123. * @max_read_size: If non-zero, the maximum number of bytes which can
  124. * be read at once.
  125. * @max_write_size: If non-zero, the maximum number of bytes which can
  126. * be written at once.
  127. * @memory_map: Address of read-only SPI flash access.
  128. * @flags: Indication of SPI flags.
  129. */
  130. struct spi_slave {
  131. #if CONFIG_IS_ENABLED(DM_SPI)
  132. struct udevice *dev; /* struct spi_slave is dev->parentdata */
  133. uint max_hz;
  134. #else
  135. unsigned int bus;
  136. unsigned int cs;
  137. #endif
  138. uint mode;
  139. unsigned int wordlen;
  140. unsigned int max_read_size;
  141. unsigned int max_write_size;
  142. void *memory_map;
  143. u8 flags;
  144. #define SPI_XFER_BEGIN BIT(0) /* Assert CS before transfer */
  145. #define SPI_XFER_END BIT(1) /* Deassert CS after transfer */
  146. #define SPI_XFER_ONCE (SPI_XFER_BEGIN | SPI_XFER_END)
  147. };
  148. /**
  149. * spi_do_alloc_slave - Allocate a new SPI slave (internal)
  150. *
  151. * Allocate and zero all fields in the spi slave, and set the bus/chip
  152. * select. Use the helper macro spi_alloc_slave() to call this.
  153. *
  154. * @offset: Offset of struct spi_slave within slave structure.
  155. * @size: Size of slave structure.
  156. * @bus: Bus ID of the slave chip.
  157. * @cs: Chip select ID of the slave chip on the specified bus.
  158. */
  159. void *spi_do_alloc_slave(int offset, int size, unsigned int bus,
  160. unsigned int cs);
  161. /**
  162. * spi_alloc_slave - Allocate a new SPI slave
  163. *
  164. * Allocate and zero all fields in the spi slave, and set the bus/chip
  165. * select.
  166. *
  167. * @_struct: Name of structure to allocate (e.g. struct tegra_spi).
  168. * This structure must contain a member 'struct spi_slave *slave'.
  169. * @bus: Bus ID of the slave chip.
  170. * @cs: Chip select ID of the slave chip on the specified bus.
  171. */
  172. #define spi_alloc_slave(_struct, bus, cs) \
  173. spi_do_alloc_slave(offsetof(_struct, slave), \
  174. sizeof(_struct), bus, cs)
  175. /**
  176. * spi_alloc_slave_base - Allocate a new SPI slave with no private data
  177. *
  178. * Allocate and zero all fields in the spi slave, and set the bus/chip
  179. * select.
  180. *
  181. * @bus: Bus ID of the slave chip.
  182. * @cs: Chip select ID of the slave chip on the specified bus.
  183. */
  184. #define spi_alloc_slave_base(bus, cs) \
  185. spi_do_alloc_slave(0, sizeof(struct spi_slave), bus, cs)
  186. /**
  187. * Set up communications parameters for a SPI slave.
  188. *
  189. * This must be called once for each slave. Note that this function
  190. * usually doesn't touch any actual hardware, it only initializes the
  191. * contents of spi_slave so that the hardware can be easily
  192. * initialized later.
  193. *
  194. * @bus: Bus ID of the slave chip.
  195. * @cs: Chip select ID of the slave chip on the specified bus.
  196. * @max_hz: Maximum SCK rate in Hz.
  197. * @mode: Clock polarity, clock phase and other parameters.
  198. *
  199. * Returns: A spi_slave reference that can be used in subsequent SPI
  200. * calls, or NULL if one or more of the parameters are not supported.
  201. */
  202. struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
  203. unsigned int max_hz, unsigned int mode);
  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. * Claim the bus and prepare it for communication with a given slave.
  212. *
  213. * This must be called before doing any transfers with a SPI slave. It
  214. * will enable and initialize any SPI hardware as necessary, and make
  215. * sure that the SCK line is in the correct idle state. It is not
  216. * allowed to claim the same bus for several slaves without releasing
  217. * the bus in between.
  218. *
  219. * @slave: The SPI slave
  220. *
  221. * Returns: 0 if the bus was claimed successfully, or a negative value
  222. * if it wasn't.
  223. */
  224. int spi_claim_bus(struct spi_slave *slave);
  225. /**
  226. * Release the SPI bus
  227. *
  228. * This must be called once for every call to spi_claim_bus() after
  229. * all transfers have finished. It may disable any SPI hardware as
  230. * appropriate.
  231. *
  232. * @slave: The SPI slave
  233. */
  234. void spi_release_bus(struct spi_slave *slave);
  235. /**
  236. * Set the word length for SPI transactions
  237. *
  238. * Set the word length (number of bits per word) for SPI transactions.
  239. *
  240. * @slave: The SPI slave
  241. * @wordlen: The number of bits in a word
  242. *
  243. * Returns: 0 on success, -1 on failure.
  244. */
  245. int spi_set_wordlen(struct spi_slave *slave, unsigned int wordlen);
  246. /**
  247. * SPI transfer (optional if mem_ops is used)
  248. *
  249. * This writes "bitlen" bits out the SPI MOSI port and simultaneously clocks
  250. * "bitlen" bits in the SPI MISO port. That's just the way SPI works.
  251. *
  252. * The source of the outgoing bits is the "dout" parameter and the
  253. * destination of the input bits is the "din" parameter. Note that "dout"
  254. * and "din" can point to the same memory location, in which case the
  255. * input data overwrites the output data (since both are buffered by
  256. * temporary variables, this is OK).
  257. *
  258. * spi_xfer() interface:
  259. * @slave: The SPI slave which will be sending/receiving the data.
  260. * @bitlen: How many bits to write and read.
  261. * @dout: Pointer to a string of bits to send out. The bits are
  262. * held in a byte array and are sent MSB first.
  263. * @din: Pointer to a string of bits that will be filled in.
  264. * @flags: A bitwise combination of SPI_XFER_* flags.
  265. *
  266. * Returns: 0 on success, not 0 on failure
  267. */
  268. int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
  269. void *din, unsigned long flags);
  270. /**
  271. * spi_write_then_read - SPI synchronous write followed by read
  272. *
  273. * This performs a half duplex transaction in which the first transaction
  274. * is to send the opcode and if the length of buf is non-zero then it start
  275. * the second transaction as tx or rx based on the need from respective slave.
  276. *
  277. * @slave: The SPI slave device with which opcode/data will be exchanged
  278. * @opcode: opcode used for specific transfer
  279. * @n_opcode: size of opcode, in bytes
  280. * @txbuf: buffer into which data to be written
  281. * @rxbuf: buffer into which data will be read
  282. * @n_buf: size of buf (whether it's [tx|rx]buf), in bytes
  283. *
  284. * Returns: 0 on success, not 0 on failure
  285. */
  286. int spi_write_then_read(struct spi_slave *slave, const u8 *opcode,
  287. size_t n_opcode, const u8 *txbuf, u8 *rxbuf,
  288. size_t n_buf);
  289. /* Copy memory mapped data */
  290. void spi_flash_copy_mmap(void *data, void *offset, size_t len);
  291. /**
  292. * Determine if a SPI chipselect is valid.
  293. * This function is provided by the board if the low-level SPI driver
  294. * needs it to determine if a given chipselect is actually valid.
  295. *
  296. * Returns: 1 if bus:cs identifies a valid chip on this board, 0
  297. * otherwise.
  298. */
  299. int spi_cs_is_valid(unsigned int bus, unsigned int cs);
  300. /*
  301. * These names are used in several drivers and these declarations will be
  302. * removed soon as part of the SPI DM migration. Drop them if driver model is
  303. * enabled for SPI.
  304. */
  305. #if !CONFIG_IS_ENABLED(DM_SPI)
  306. /**
  307. * Activate 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 activate the chip select
  311. * to the device identified by "slave".
  312. */
  313. void spi_cs_activate(struct spi_slave *slave);
  314. /**
  315. * Deactivate a SPI chipselect.
  316. * This function is provided by the board code when using a driver
  317. * that can't control its chipselects automatically (e.g.
  318. * common/soft_spi.c). When called, it should deactivate the chip
  319. * select to the device identified by "slave".
  320. */
  321. void spi_cs_deactivate(struct spi_slave *slave);
  322. #endif
  323. /**
  324. * Set transfer speed.
  325. * This sets a new speed to be applied for next spi_xfer().
  326. * @slave: The SPI slave
  327. * @hz: The transfer speed
  328. */
  329. void spi_set_speed(struct spi_slave *slave, uint hz);
  330. /**
  331. * Write 8 bits, then read 8 bits.
  332. * @slave: The SPI slave we're communicating with
  333. * @byte: Byte to be written
  334. *
  335. * Returns: The value that was read, or a negative value on error.
  336. *
  337. * TODO: This function probably shouldn't be inlined.
  338. */
  339. static inline int spi_w8r8(struct spi_slave *slave, unsigned char byte)
  340. {
  341. unsigned char dout[2];
  342. unsigned char din[2];
  343. int ret;
  344. dout[0] = byte;
  345. dout[1] = 0;
  346. ret = spi_xfer(slave, 16, dout, din, SPI_XFER_BEGIN | SPI_XFER_END);
  347. return ret < 0 ? ret : din[1];
  348. }
  349. /**
  350. * struct spi_cs_info - Information about a bus chip select
  351. *
  352. * @dev: Connected device, or NULL if none
  353. */
  354. struct spi_cs_info {
  355. struct udevice *dev;
  356. };
  357. /**
  358. * struct struct dm_spi_ops - Driver model SPI operations
  359. *
  360. * The uclass interface is implemented by all SPI devices which use
  361. * driver model.
  362. */
  363. struct dm_spi_ops {
  364. /**
  365. * Claim the bus and prepare it for communication.
  366. *
  367. * The device provided is the slave device. It's parent controller
  368. * will be used to provide the communication.
  369. *
  370. * This must be called before doing any transfers with a SPI slave. It
  371. * will enable and initialize any SPI hardware as necessary, and make
  372. * sure that the SCK line is in the correct idle state. It is not
  373. * allowed to claim the same bus for several slaves without releasing
  374. * the bus in between.
  375. *
  376. * @dev: The SPI slave
  377. *
  378. * Returns: 0 if the bus was claimed successfully, or a negative value
  379. * if it wasn't.
  380. */
  381. int (*claim_bus)(struct udevice *dev);
  382. /**
  383. * Release the SPI bus
  384. *
  385. * This must be called once for every call to spi_claim_bus() after
  386. * all transfers have finished. It may disable any SPI hardware as
  387. * appropriate.
  388. *
  389. * @dev: The SPI slave
  390. */
  391. int (*release_bus)(struct udevice *dev);
  392. /**
  393. * Set the word length for SPI transactions
  394. *
  395. * Set the word length (number of bits per word) for SPI transactions.
  396. *
  397. * @bus: The SPI slave
  398. * @wordlen: The number of bits in a word
  399. *
  400. * Returns: 0 on success, -ve on failure.
  401. */
  402. int (*set_wordlen)(struct udevice *dev, unsigned int wordlen);
  403. /**
  404. * SPI transfer
  405. *
  406. * This writes "bitlen" bits out the SPI MOSI port and simultaneously
  407. * clocks "bitlen" bits in the SPI MISO port. That's just the way SPI
  408. * works.
  409. *
  410. * The source of the outgoing bits is the "dout" parameter and the
  411. * destination of the input bits is the "din" parameter. Note that
  412. * "dout" and "din" can point to the same memory location, in which
  413. * case the input data overwrites the output data (since both are
  414. * buffered by temporary variables, this is OK).
  415. *
  416. * spi_xfer() interface:
  417. * @dev: The slave device to communicate with
  418. * @bitlen: How many bits to write and read.
  419. * @dout: Pointer to a string of bits to send out. The bits are
  420. * held in a byte array and are sent MSB first.
  421. * @din: Pointer to a string of bits that will be filled in.
  422. * @flags: A bitwise combination of SPI_XFER_* flags.
  423. *
  424. * Returns: 0 on success, not -1 on failure
  425. */
  426. int (*xfer)(struct udevice *dev, unsigned int bitlen, const void *dout,
  427. void *din, unsigned long flags);
  428. /**
  429. * Optimized handlers for SPI memory-like operations.
  430. *
  431. * Optimized/dedicated operations for interactions with SPI memory. This
  432. * field is optional and should only be implemented if the controller
  433. * has native support for memory like operations.
  434. */
  435. const struct spi_controller_mem_ops *mem_ops;
  436. /**
  437. * Set transfer speed.
  438. * This sets a new speed to be applied for next spi_xfer().
  439. * @bus: The SPI bus
  440. * @hz: The transfer speed
  441. * @return 0 if OK, -ve on error
  442. */
  443. int (*set_speed)(struct udevice *bus, uint hz);
  444. /**
  445. * Set the SPI mode/flags
  446. *
  447. * It is unclear if we want to set speed and mode together instead
  448. * of separately.
  449. *
  450. * @bus: The SPI bus
  451. * @mode: Requested SPI mode (SPI_... flags)
  452. * @return 0 if OK, -ve on error
  453. */
  454. int (*set_mode)(struct udevice *bus, uint mode);
  455. /**
  456. * Get information on a chip select
  457. *
  458. * This is only called when the SPI uclass does not know about a
  459. * chip select, i.e. it has no attached device. It gives the driver
  460. * a chance to allow activity on that chip select even so.
  461. *
  462. * @bus: The SPI bus
  463. * @cs: The chip select (0..n-1)
  464. * @info: Returns information about the chip select, if valid.
  465. * On entry info->dev is NULL
  466. * @return 0 if OK (and @info is set up), -EINVAL if the chip select
  467. * is invalid, other -ve value on error
  468. */
  469. int (*cs_info)(struct udevice *bus, uint cs, struct spi_cs_info *info);
  470. /**
  471. * get_mmap() - Get memory-mapped SPI
  472. *
  473. * @dev: The SPI flash slave device
  474. * @map_basep: Returns base memory address for mapped SPI
  475. * @map_sizep: Returns size of mapped SPI
  476. * @offsetp: Returns start offset of SPI flash where the map works
  477. * correctly (offsets before this are not visible)
  478. * @return 0 if OK, -EFAULT if memory mapping is not available
  479. */
  480. int (*get_mmap)(struct udevice *dev, ulong *map_basep,
  481. uint *map_sizep, uint *offsetp);
  482. };
  483. struct dm_spi_emul_ops {
  484. /**
  485. * SPI transfer
  486. *
  487. * This writes "bitlen" bits out the SPI MOSI port and simultaneously
  488. * clocks "bitlen" bits in the SPI MISO port. That's just the way SPI
  489. * works. Here the device is a slave.
  490. *
  491. * The source of the outgoing bits is the "dout" parameter and the
  492. * destination of the input bits is the "din" parameter. Note that
  493. * "dout" and "din" can point to the same memory location, in which
  494. * case the input data overwrites the output data (since both are
  495. * buffered by temporary variables, this is OK).
  496. *
  497. * spi_xfer() interface:
  498. * @slave: The SPI slave which will be sending/receiving the data.
  499. * @bitlen: How many bits to write and read.
  500. * @dout: Pointer to a string of bits sent to the device. The
  501. * bits are held in a byte array and are sent MSB first.
  502. * @din: Pointer to a string of bits that will be sent back to
  503. * the master.
  504. * @flags: A bitwise combination of SPI_XFER_* flags.
  505. *
  506. * Returns: 0 on success, not -1 on failure
  507. */
  508. int (*xfer)(struct udevice *slave, unsigned int bitlen,
  509. const void *dout, void *din, unsigned long flags);
  510. };
  511. /**
  512. * spi_find_bus_and_cs() - Find bus and slave devices by number
  513. *
  514. * Given a bus number and chip select, this finds the corresponding bus
  515. * device and slave device. Neither device is activated by this function,
  516. * although they may have been activated previously.
  517. *
  518. * @busnum: SPI bus number
  519. * @cs: Chip select to look for
  520. * @busp: Returns bus device
  521. * @devp: Return slave device
  522. * @return 0 if found, -ENODEV on error
  523. */
  524. int spi_find_bus_and_cs(int busnum, int cs, struct udevice **busp,
  525. struct udevice **devp);
  526. /**
  527. * spi_get_bus_and_cs() - Find and activate bus and slave devices by number
  528. *
  529. * Given a bus number and chip select, this finds the corresponding bus
  530. * device and slave device.
  531. *
  532. * If no such slave exists, and drv_name is not NULL, then a new slave device
  533. * is automatically bound on this chip select with requested speed and mode.
  534. *
  535. * Ths new slave device is probed ready for use with the speed and mode
  536. * from plat when available or the requested values.
  537. *
  538. * @busnum: SPI bus number
  539. * @cs: Chip select to look for
  540. * @speed: SPI speed to use for this slave when not available in plat
  541. * @mode: SPI mode to use for this slave when not available in plat
  542. * @drv_name: Name of driver to attach to this chip select
  543. * @dev_name: Name of the new device thus created
  544. * @busp: Returns bus device
  545. * @devp: Return slave device
  546. * @return 0 if found, -ve on error
  547. */
  548. int spi_get_bus_and_cs(int busnum, int cs, int speed, int mode,
  549. const char *drv_name, const char *dev_name,
  550. struct udevice **busp, struct spi_slave **devp);
  551. /**
  552. * spi_chip_select() - Get the chip select for a slave
  553. *
  554. * @return the chip select this slave is attached to
  555. */
  556. int spi_chip_select(struct udevice *slave);
  557. /**
  558. * spi_find_chip_select() - Find the slave attached to chip select
  559. *
  560. * @bus: SPI bus to search
  561. * @cs: Chip select to look for
  562. * @devp: Returns the slave device if found
  563. * @return 0 if found, -EINVAL if cs is invalid, -ENODEV if no device attached,
  564. * other -ve value on error
  565. */
  566. int spi_find_chip_select(struct udevice *bus, int cs, struct udevice **devp);
  567. /**
  568. * spi_slave_of_to_plat() - decode standard SPI platform data
  569. *
  570. * This decodes the speed and mode for a slave from a device tree node
  571. *
  572. * @blob: Device tree blob
  573. * @node: Node offset to read from
  574. * @plat: Place to put the decoded information
  575. */
  576. int spi_slave_of_to_plat(struct udevice *dev, struct dm_spi_slave_plat *plat);
  577. /**
  578. * spi_cs_info() - Check information on a chip select
  579. *
  580. * This checks a particular chip select on a bus to see if it has a device
  581. * attached, or is even valid.
  582. *
  583. * @bus: The SPI bus
  584. * @cs: The chip select (0..n-1)
  585. * @info: Returns information about the chip select, if valid
  586. * @return 0 if OK (and @info is set up), -ENODEV if the chip select
  587. * is invalid, other -ve value on error
  588. */
  589. int spi_cs_info(struct udevice *bus, uint cs, struct spi_cs_info *info);
  590. struct sandbox_state;
  591. /**
  592. * sandbox_spi_get_emul() - get an emulator for a SPI slave
  593. *
  594. * This provides a way to attach an emulated SPI device to a particular SPI
  595. * slave, so that xfer() operations on the slave will be handled by the
  596. * emulator. If a emulator already exists on that chip select it is returned.
  597. * Otherwise one is created.
  598. *
  599. * @state: Sandbox state
  600. * @bus: SPI bus requesting the emulator
  601. * @slave: SPI slave device requesting the emulator
  602. * @emuip: Returns pointer to emulator
  603. * @return 0 if OK, -ve on error
  604. */
  605. int sandbox_spi_get_emul(struct sandbox_state *state,
  606. struct udevice *bus, struct udevice *slave,
  607. struct udevice **emulp);
  608. /**
  609. * Claim the bus and prepare it for communication with a given slave.
  610. *
  611. * This must be called before doing any transfers with a SPI slave. It
  612. * will enable and initialize any SPI hardware as necessary, and make
  613. * sure that the SCK line is in the correct idle state. It is not
  614. * allowed to claim the same bus for several slaves without releasing
  615. * the bus in between.
  616. *
  617. * @dev: The SPI slave device
  618. *
  619. * Returns: 0 if the bus was claimed successfully, or a negative value
  620. * if it wasn't.
  621. */
  622. int dm_spi_claim_bus(struct udevice *dev);
  623. /**
  624. * Release the SPI bus
  625. *
  626. * This must be called once for every call to dm_spi_claim_bus() after
  627. * all transfers have finished. It may disable any SPI hardware as
  628. * appropriate.
  629. *
  630. * @slave: The SPI slave device
  631. */
  632. void dm_spi_release_bus(struct udevice *dev);
  633. /**
  634. * SPI transfer
  635. *
  636. * This writes "bitlen" bits out the SPI MOSI port and simultaneously clocks
  637. * "bitlen" bits in the SPI MISO port. That's just the way SPI works.
  638. *
  639. * The source of the outgoing bits is the "dout" parameter and the
  640. * destination of the input bits is the "din" parameter. Note that "dout"
  641. * and "din" can point to the same memory location, in which case the
  642. * input data overwrites the output data (since both are buffered by
  643. * temporary variables, this is OK).
  644. *
  645. * dm_spi_xfer() interface:
  646. * @dev: The SPI slave device which will be sending/receiving the data.
  647. * @bitlen: How many bits to write and read.
  648. * @dout: Pointer to a string of bits to send out. The bits are
  649. * held in a byte array and are sent MSB first.
  650. * @din: Pointer to a string of bits that will be filled in.
  651. * @flags: A bitwise combination of SPI_XFER_* flags.
  652. *
  653. * Returns: 0 on success, not 0 on failure
  654. */
  655. int dm_spi_xfer(struct udevice *dev, unsigned int bitlen,
  656. const void *dout, void *din, unsigned long flags);
  657. /**
  658. * spi_get_mmap() - Get memory-mapped SPI
  659. *
  660. * @dev: SPI slave device to check
  661. * @map_basep: Returns base memory address for mapped SPI
  662. * @map_sizep: Returns size of mapped SPI
  663. * @offsetp: Returns start offset of SPI flash where the map works
  664. * correctly (offsets before this are not visible)
  665. * @return 0 if OK, -ENOSYS if no operation, -EFAULT if memory mapping is not
  666. * available
  667. */
  668. int dm_spi_get_mmap(struct udevice *dev, ulong *map_basep, uint *map_sizep,
  669. uint *offsetp);
  670. /* Access the operations for a SPI device */
  671. #define spi_get_ops(dev) ((struct dm_spi_ops *)(dev)->driver->ops)
  672. #define spi_emul_get_ops(dev) ((struct dm_spi_emul_ops *)(dev)->driver->ops)
  673. #endif /* _SPI_H_ */