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. /* SPI mode flags */
  12. #define SPI_CPHA BIT(0) /* clock phase */
  13. #define SPI_CPOL BIT(1) /* clock polarity */
  14. #define SPI_MODE_0 (0|0) /* (original MicroWire) */
  15. #define SPI_MODE_1 (0|SPI_CPHA)
  16. #define SPI_MODE_2 (SPI_CPOL|0)
  17. #define SPI_MODE_3 (SPI_CPOL|SPI_CPHA)
  18. #define SPI_CS_HIGH BIT(2) /* CS active high */
  19. #define SPI_LSB_FIRST BIT(3) /* per-word bits-on-wire */
  20. #define SPI_3WIRE BIT(4) /* SI/SO signals shared */
  21. #define SPI_LOOP BIT(5) /* loopback mode */
  22. #define SPI_SLAVE BIT(6) /* slave mode */
  23. #define SPI_PREAMBLE BIT(7) /* Skip preamble bytes */
  24. #define SPI_TX_BYTE BIT(8) /* transmit with 1 wire byte */
  25. #define SPI_TX_DUAL BIT(9) /* transmit with 2 wires */
  26. #define SPI_TX_QUAD BIT(10) /* transmit with 4 wires */
  27. #define SPI_RX_SLOW BIT(11) /* receive with 1 wire slow */
  28. #define SPI_RX_DUAL BIT(12) /* receive with 2 wires */
  29. #define SPI_RX_QUAD BIT(13) /* receive with 4 wires */
  30. #define SPI_TX_OCTAL BIT(14) /* transmit with 8 wires */
  31. #define SPI_RX_OCTAL BIT(15) /* receive with 8 wires */
  32. /* Header byte that marks the start of the message */
  33. #define SPI_PREAMBLE_END_BYTE 0xec
  34. #define SPI_DEFAULT_WORDLEN 8
  35. #ifdef CONFIG_DM_SPI
  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. #endif /* CONFIG_DM_SPI */
  60. /**
  61. * enum spi_clock_phase - indicates the clock phase to use for SPI (CPHA)
  62. *
  63. * @SPI_CLOCK_PHASE_FIRST: Data sampled on the first phase
  64. * @SPI_CLOCK_PHASE_SECOND: Data sampled on the second phase
  65. */
  66. enum spi_clock_phase {
  67. SPI_CLOCK_PHASE_FIRST,
  68. SPI_CLOCK_PHASE_SECOND,
  69. };
  70. /**
  71. * enum spi_wire_mode - indicates the number of wires used for SPI
  72. *
  73. * @SPI_4_WIRE_MODE: Normal bidirectional mode with MOSI and MISO
  74. * @SPI_3_WIRE_MODE: Unidirectional version with a single data line SISO
  75. */
  76. enum spi_wire_mode {
  77. SPI_4_WIRE_MODE,
  78. SPI_3_WIRE_MODE,
  79. };
  80. /**
  81. * enum spi_polarity - indicates the polarity of the SPI bus (CPOL)
  82. *
  83. * @SPI_POLARITY_LOW: Clock is low in idle state
  84. * @SPI_POLARITY_HIGH: Clock is high in idle state
  85. */
  86. enum spi_polarity {
  87. SPI_POLARITY_LOW,
  88. SPI_POLARITY_HIGH,
  89. };
  90. /**
  91. * struct spi_slave - Representation of a SPI slave
  92. *
  93. * For driver model this is the per-child data used by the SPI bus. It can
  94. * be accessed using dev_get_parent_priv() on the slave device. The SPI uclass
  95. * sets uip per_child_auto_alloc_size to sizeof(struct spi_slave), and the
  96. * driver should not override it. Two platform data fields (max_hz and mode)
  97. * are copied into this structure to provide an initial value. This allows
  98. * them to be changed, since we should never change platform data in drivers.
  99. *
  100. * If not using driver model, drivers are expected to extend this with
  101. * controller-specific data.
  102. *
  103. * @dev: SPI slave device
  104. * @max_hz: Maximum speed for this slave
  105. * @speed: Current bus speed. This is 0 until the bus is first
  106. * claimed.
  107. * @bus: ID of the bus that the slave is attached to. For
  108. * driver model this is the sequence number of the SPI
  109. * bus (bus->seq) so does not need to be stored
  110. * @cs: ID of the chip select connected to the slave.
  111. * @mode: SPI mode to use for this slave (see SPI mode flags)
  112. * @wordlen: Size of SPI word in number of bits
  113. * @max_read_size: If non-zero, the maximum number of bytes which can
  114. * be read at once.
  115. * @max_write_size: If non-zero, the maximum number of bytes which can
  116. * be written at once.
  117. * @memory_map: Address of read-only SPI flash access.
  118. * @flags: Indication of SPI flags.
  119. */
  120. struct spi_slave {
  121. #ifdef CONFIG_DM_SPI
  122. struct udevice *dev; /* struct spi_slave is dev->parentdata */
  123. uint max_hz;
  124. uint speed;
  125. #else
  126. unsigned int bus;
  127. unsigned int cs;
  128. #endif
  129. uint mode;
  130. unsigned int wordlen;
  131. unsigned int max_read_size;
  132. unsigned int max_write_size;
  133. void *memory_map;
  134. u8 flags;
  135. #define SPI_XFER_BEGIN BIT(0) /* Assert CS before transfer */
  136. #define SPI_XFER_END BIT(1) /* Deassert CS after transfer */
  137. #define SPI_XFER_ONCE (SPI_XFER_BEGIN | SPI_XFER_END)
  138. #define SPI_XFER_MMAP BIT(2) /* Memory Mapped start */
  139. #define SPI_XFER_MMAP_END BIT(3) /* Memory Mapped End */
  140. };
  141. /**
  142. * spi_do_alloc_slave - Allocate a new SPI slave (internal)
  143. *
  144. * Allocate and zero all fields in the spi slave, and set the bus/chip
  145. * select. Use the helper macro spi_alloc_slave() to call this.
  146. *
  147. * @offset: Offset of struct spi_slave within slave structure.
  148. * @size: Size of slave structure.
  149. * @bus: Bus ID of the slave chip.
  150. * @cs: Chip select ID of the slave chip on the specified bus.
  151. */
  152. void *spi_do_alloc_slave(int offset, int size, unsigned int bus,
  153. unsigned int cs);
  154. /**
  155. * spi_alloc_slave - Allocate a new SPI slave
  156. *
  157. * Allocate and zero all fields in the spi slave, and set the bus/chip
  158. * select.
  159. *
  160. * @_struct: Name of structure to allocate (e.g. struct tegra_spi).
  161. * This structure must contain a member 'struct spi_slave *slave'.
  162. * @bus: Bus ID of the slave chip.
  163. * @cs: Chip select ID of the slave chip on the specified bus.
  164. */
  165. #define spi_alloc_slave(_struct, bus, cs) \
  166. spi_do_alloc_slave(offsetof(_struct, slave), \
  167. sizeof(_struct), bus, cs)
  168. /**
  169. * spi_alloc_slave_base - Allocate a new SPI slave with no private data
  170. *
  171. * Allocate and zero all fields in the spi slave, and set the bus/chip
  172. * select.
  173. *
  174. * @bus: Bus ID of the slave chip.
  175. * @cs: Chip select ID of the slave chip on the specified bus.
  176. */
  177. #define spi_alloc_slave_base(bus, cs) \
  178. spi_do_alloc_slave(0, sizeof(struct spi_slave), bus, cs)
  179. /**
  180. * Set up communications parameters for a SPI slave.
  181. *
  182. * This must be called once for each slave. Note that this function
  183. * usually doesn't touch any actual hardware, it only initializes the
  184. * contents of spi_slave so that the hardware can be easily
  185. * initialized later.
  186. *
  187. * @bus: Bus ID of the slave chip.
  188. * @cs: Chip select ID of the slave chip on the specified bus.
  189. * @max_hz: Maximum SCK rate in Hz.
  190. * @mode: Clock polarity, clock phase and other parameters.
  191. *
  192. * Returns: A spi_slave reference that can be used in subsequent SPI
  193. * calls, or NULL if one or more of the parameters are not supported.
  194. */
  195. struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
  196. unsigned int max_hz, unsigned int mode);
  197. /**
  198. * Free any memory associated with a SPI slave.
  199. *
  200. * @slave: The SPI slave
  201. */
  202. void spi_free_slave(struct spi_slave *slave);
  203. /**
  204. * Claim the bus and prepare it for communication with a given slave.
  205. *
  206. * This must be called before doing any transfers with a SPI slave. It
  207. * will enable and initialize any SPI hardware as necessary, and make
  208. * sure that the SCK line is in the correct idle state. It is not
  209. * allowed to claim the same bus for several slaves without releasing
  210. * the bus in between.
  211. *
  212. * @slave: The SPI slave
  213. *
  214. * Returns: 0 if the bus was claimed successfully, or a negative value
  215. * if it wasn't.
  216. */
  217. int spi_claim_bus(struct spi_slave *slave);
  218. /**
  219. * Release the SPI bus
  220. *
  221. * This must be called once for every call to spi_claim_bus() after
  222. * all transfers have finished. It may disable any SPI hardware as
  223. * appropriate.
  224. *
  225. * @slave: The SPI slave
  226. */
  227. void spi_release_bus(struct spi_slave *slave);
  228. /**
  229. * Set the word length for SPI transactions
  230. *
  231. * Set the word length (number of bits per word) for SPI transactions.
  232. *
  233. * @slave: The SPI slave
  234. * @wordlen: The number of bits in a word
  235. *
  236. * Returns: 0 on success, -1 on failure.
  237. */
  238. int spi_set_wordlen(struct spi_slave *slave, unsigned int wordlen);
  239. /**
  240. * SPI transfer (optional if mem_ops is used)
  241. *
  242. * This writes "bitlen" bits out the SPI MOSI port and simultaneously clocks
  243. * "bitlen" bits in the SPI MISO port. That's just the way SPI works.
  244. *
  245. * The source of the outgoing bits is the "dout" parameter and the
  246. * destination of the input bits is the "din" parameter. Note that "dout"
  247. * and "din" can point to the same memory location, in which case the
  248. * input data overwrites the output data (since both are buffered by
  249. * temporary variables, this is OK).
  250. *
  251. * spi_xfer() interface:
  252. * @slave: The SPI slave which will be sending/receiving the data.
  253. * @bitlen: How many bits to write and read.
  254. * @dout: Pointer to a string of bits to send out. The bits are
  255. * held in a byte array and are sent MSB first.
  256. * @din: Pointer to a string of bits that will be filled in.
  257. * @flags: A bitwise combination of SPI_XFER_* flags.
  258. *
  259. * Returns: 0 on success, not 0 on failure
  260. */
  261. int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
  262. void *din, unsigned long flags);
  263. /**
  264. * spi_write_then_read - SPI synchronous write followed by read
  265. *
  266. * This performs a half duplex transaction in which the first transaction
  267. * is to send the opcode and if the length of buf is non-zero then it start
  268. * the second transaction as tx or rx based on the need from respective slave.
  269. *
  270. * @slave: The SPI slave device with which opcode/data will be exchanged
  271. * @opcode: opcode used for specific transfer
  272. * @n_opcode: size of opcode, in bytes
  273. * @txbuf: buffer into which data to be written
  274. * @rxbuf: buffer into which data will be read
  275. * @n_buf: size of buf (whether it's [tx|rx]buf), in bytes
  276. *
  277. * Returns: 0 on success, not 0 on failure
  278. */
  279. int spi_write_then_read(struct spi_slave *slave, const u8 *opcode,
  280. size_t n_opcode, const u8 *txbuf, u8 *rxbuf,
  281. size_t n_buf);
  282. /* Copy memory mapped data */
  283. void spi_flash_copy_mmap(void *data, void *offset, size_t len);
  284. /**
  285. * Determine if a SPI chipselect is valid.
  286. * This function is provided by the board if the low-level SPI driver
  287. * needs it to determine if a given chipselect is actually valid.
  288. *
  289. * Returns: 1 if bus:cs identifies a valid chip on this board, 0
  290. * otherwise.
  291. */
  292. int spi_cs_is_valid(unsigned int bus, unsigned int cs);
  293. #ifndef CONFIG_DM_SPI
  294. /**
  295. * Activate 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 activate the chip select
  299. * to the device identified by "slave".
  300. */
  301. void spi_cs_activate(struct spi_slave *slave);
  302. /**
  303. * Deactivate a SPI chipselect.
  304. * This function is provided by the board code when using a driver
  305. * that can't control its chipselects automatically (e.g.
  306. * common/soft_spi.c). When called, it should deactivate the chip
  307. * select to the device identified by "slave".
  308. */
  309. void spi_cs_deactivate(struct spi_slave *slave);
  310. /**
  311. * Set transfer speed.
  312. * This sets a new speed to be applied for next spi_xfer().
  313. * @slave: The SPI slave
  314. * @hz: The transfer speed
  315. */
  316. void spi_set_speed(struct spi_slave *slave, uint hz);
  317. #endif
  318. /**
  319. * Write 8 bits, then read 8 bits.
  320. * @slave: The SPI slave we're communicating with
  321. * @byte: Byte to be written
  322. *
  323. * Returns: The value that was read, or a negative value on error.
  324. *
  325. * TODO: This function probably shouldn't be inlined.
  326. */
  327. static inline int spi_w8r8(struct spi_slave *slave, unsigned char byte)
  328. {
  329. unsigned char dout[2];
  330. unsigned char din[2];
  331. int ret;
  332. dout[0] = byte;
  333. dout[1] = 0;
  334. ret = spi_xfer(slave, 16, dout, din, SPI_XFER_BEGIN | SPI_XFER_END);
  335. return ret < 0 ? ret : din[1];
  336. }
  337. #ifdef CONFIG_DM_SPI
  338. /**
  339. * struct spi_cs_info - Information about a bus chip select
  340. *
  341. * @dev: Connected device, or NULL if none
  342. */
  343. struct spi_cs_info {
  344. struct udevice *dev;
  345. };
  346. /**
  347. * struct struct dm_spi_ops - Driver model SPI operations
  348. *
  349. * The uclass interface is implemented by all SPI devices which use
  350. * driver model.
  351. */
  352. struct dm_spi_ops {
  353. /**
  354. * Claim the bus and prepare it for communication.
  355. *
  356. * The device provided is the slave device. It's parent controller
  357. * will be used to provide the communication.
  358. *
  359. * This must be called before doing any transfers with a SPI slave. It
  360. * will enable and initialize any SPI hardware as necessary, and make
  361. * sure that the SCK line is in the correct idle state. It is not
  362. * allowed to claim the same bus for several slaves without releasing
  363. * the bus in between.
  364. *
  365. * @dev: The SPI slave
  366. *
  367. * Returns: 0 if the bus was claimed successfully, or a negative value
  368. * if it wasn't.
  369. */
  370. int (*claim_bus)(struct udevice *dev);
  371. /**
  372. * Release the SPI bus
  373. *
  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
  376. * appropriate.
  377. *
  378. * @dev: The SPI slave
  379. */
  380. int (*release_bus)(struct udevice *dev);
  381. /**
  382. * Set the word length for SPI transactions
  383. *
  384. * Set the word length (number of bits per word) for SPI transactions.
  385. *
  386. * @bus: The SPI slave
  387. * @wordlen: The number of bits in a word
  388. *
  389. * Returns: 0 on success, -ve on failure.
  390. */
  391. int (*set_wordlen)(struct udevice *dev, unsigned int wordlen);
  392. /**
  393. * SPI transfer
  394. *
  395. * This writes "bitlen" bits out the SPI MOSI port and simultaneously
  396. * clocks "bitlen" bits in the SPI MISO port. That's just the way SPI
  397. * works.
  398. *
  399. * The source of the outgoing bits is the "dout" parameter and the
  400. * destination of the input bits is the "din" parameter. Note that
  401. * "dout" and "din" can point to the same memory location, in which
  402. * case the input data overwrites the output data (since both are
  403. * buffered by temporary variables, this is OK).
  404. *
  405. * spi_xfer() interface:
  406. * @dev: The slave device to communicate with
  407. * @bitlen: How many bits to write and read.
  408. * @dout: Pointer to a string of bits to send out. The bits are
  409. * held in a byte array and are sent MSB first.
  410. * @din: Pointer to a string of bits that will be filled in.
  411. * @flags: A bitwise combination of SPI_XFER_* flags.
  412. *
  413. * Returns: 0 on success, not -1 on failure
  414. */
  415. int (*xfer)(struct udevice *dev, unsigned int bitlen, const void *dout,
  416. void *din, unsigned long flags);
  417. /**
  418. * Optimized handlers for SPI memory-like operations.
  419. *
  420. * Optimized/dedicated operations for interactions with SPI memory. This
  421. * field is optional and should only be implemented if the controller
  422. * has native support for memory like operations.
  423. */
  424. const struct spi_controller_mem_ops *mem_ops;
  425. /**
  426. * Set transfer speed.
  427. * This sets a new speed to be applied for next spi_xfer().
  428. * @bus: The SPI bus
  429. * @hz: The transfer speed
  430. * @return 0 if OK, -ve on error
  431. */
  432. int (*set_speed)(struct udevice *bus, uint hz);
  433. /**
  434. * Set the SPI mode/flags
  435. *
  436. * It is unclear if we want to set speed and mode together instead
  437. * of separately.
  438. *
  439. * @bus: The SPI bus
  440. * @mode: Requested SPI mode (SPI_... flags)
  441. * @return 0 if OK, -ve on error
  442. */
  443. int (*set_mode)(struct udevice *bus, uint mode);
  444. /**
  445. * Get information on a chip select
  446. *
  447. * This is only called when the SPI uclass does not know about a
  448. * chip select, i.e. it has no attached device. It gives the driver
  449. * a chance to allow activity on that chip select even so.
  450. *
  451. * @bus: The SPI bus
  452. * @cs: The chip select (0..n-1)
  453. * @info: Returns information about the chip select, if valid.
  454. * On entry info->dev is NULL
  455. * @return 0 if OK (and @info is set up), -EINVAL if the chip select
  456. * is invalid, other -ve value on error
  457. */
  458. int (*cs_info)(struct udevice *bus, uint cs, struct spi_cs_info *info);
  459. /**
  460. * get_mmap() - Get memory-mapped SPI
  461. *
  462. * @dev: The SPI flash slave device
  463. * @map_basep: Returns base memory address for mapped SPI
  464. * @map_sizep: Returns size of mapped SPI
  465. * @offsetp: Returns start offset of SPI flash where the map works
  466. * correctly (offsets before this are not visible)
  467. * @return 0 if OK, -EFAULT if memory mapping is not available
  468. */
  469. int (*get_mmap)(struct udevice *dev, ulong *map_basep,
  470. uint *map_sizep, uint *offsetp);
  471. };
  472. struct dm_spi_emul_ops {
  473. /**
  474. * SPI transfer
  475. *
  476. * This writes "bitlen" bits out the SPI MOSI port and simultaneously
  477. * clocks "bitlen" bits in the SPI MISO port. That's just the way SPI
  478. * works. Here the device is a slave.
  479. *
  480. * The source of the outgoing bits is the "dout" parameter and the
  481. * destination of the input bits is the "din" parameter. Note that
  482. * "dout" and "din" can point to the same memory location, in which
  483. * case the input data overwrites the output data (since both are
  484. * buffered by temporary variables, this is OK).
  485. *
  486. * spi_xfer() interface:
  487. * @slave: The SPI slave which will be sending/receiving the data.
  488. * @bitlen: How many bits to write and read.
  489. * @dout: Pointer to a string of bits sent to the device. The
  490. * bits are held in a byte array and are sent MSB first.
  491. * @din: Pointer to a string of bits that will be sent back to
  492. * the master.
  493. * @flags: A bitwise combination of SPI_XFER_* flags.
  494. *
  495. * Returns: 0 on success, not -1 on failure
  496. */
  497. int (*xfer)(struct udevice *slave, unsigned int bitlen,
  498. const void *dout, void *din, unsigned long flags);
  499. };
  500. /**
  501. * spi_find_bus_and_cs() - Find bus and slave devices by number
  502. *
  503. * Given a bus number and chip select, this finds the corresponding bus
  504. * device and slave device. Neither device is activated by this function,
  505. * although they may have been activated previously.
  506. *
  507. * @busnum: SPI bus number
  508. * @cs: Chip select to look for
  509. * @busp: Returns bus device
  510. * @devp: Return slave device
  511. * @return 0 if found, -ENODEV on error
  512. */
  513. int spi_find_bus_and_cs(int busnum, int cs, struct udevice **busp,
  514. struct udevice **devp);
  515. /**
  516. * spi_get_bus_and_cs() - Find and activate bus and slave devices by number
  517. *
  518. * Given a bus number and chip select, this finds the corresponding bus
  519. * device and slave device.
  520. *
  521. * If no such slave exists, and drv_name is not NULL, then a new slave device
  522. * is automatically bound on this chip select with requested speed and mode.
  523. *
  524. * Ths new slave device is probed ready for use with the speed and mode
  525. * from platdata when available or the requested values.
  526. *
  527. * @busnum: SPI bus number
  528. * @cs: Chip select to look for
  529. * @speed: SPI speed to use for this slave when not available in platdata
  530. * @mode: SPI mode to use for this slave when not available in platdata
  531. * @drv_name: Name of driver to attach to this chip select
  532. * @dev_name: Name of the new device thus created
  533. * @busp: Returns bus device
  534. * @devp: Return slave device
  535. * @return 0 if found, -ve on error
  536. */
  537. int spi_get_bus_and_cs(int busnum, int cs, int speed, int mode,
  538. const char *drv_name, const char *dev_name,
  539. struct udevice **busp, struct spi_slave **devp);
  540. /**
  541. * spi_chip_select() - Get the chip select for a slave
  542. *
  543. * @return the chip select this slave is attached to
  544. */
  545. int spi_chip_select(struct udevice *slave);
  546. /**
  547. * spi_find_chip_select() - Find the slave attached to chip select
  548. *
  549. * @bus: SPI bus to search
  550. * @cs: Chip select to look for
  551. * @devp: Returns the slave device if found
  552. * @return 0 if found, -EINVAL if cs is invalid, -ENODEV if no device attached,
  553. * other -ve value on error
  554. */
  555. int spi_find_chip_select(struct udevice *bus, int cs, struct udevice **devp);
  556. /**
  557. * spi_slave_ofdata_to_platdata() - decode standard SPI platform data
  558. *
  559. * This decodes the speed and mode for a slave from a device tree node
  560. *
  561. * @blob: Device tree blob
  562. * @node: Node offset to read from
  563. * @plat: Place to put the decoded information
  564. */
  565. int spi_slave_ofdata_to_platdata(struct udevice *dev,
  566. struct dm_spi_slave_platdata *plat);
  567. /**
  568. * spi_cs_info() - Check information on a chip select
  569. *
  570. * This checks a particular chip select on a bus to see if it has a device
  571. * attached, or is even valid.
  572. *
  573. * @bus: The SPI bus
  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
  578. */
  579. int spi_cs_info(struct udevice *bus, uint cs, struct spi_cs_info *info);
  580. struct sandbox_state;
  581. /**
  582. * sandbox_spi_get_emul() - get an emulator for a SPI slave
  583. *
  584. * This provides a way to attach an emulated SPI device to a particular SPI
  585. * slave, so that xfer() operations on the slave will be handled by the
  586. * emulator. If a emulator already exists on that chip select it is returned.
  587. * Otherwise one is created.
  588. *
  589. * @state: Sandbox state
  590. * @bus: SPI bus requesting the emulator
  591. * @slave: SPI slave device requesting the emulator
  592. * @emuip: Returns pointer to emulator
  593. * @return 0 if OK, -ve on error
  594. */
  595. int sandbox_spi_get_emul(struct sandbox_state *state,
  596. struct udevice *bus, struct udevice *slave,
  597. struct udevice **emulp);
  598. /**
  599. * Claim the bus and prepare it for communication with a given slave.
  600. *
  601. * This must be called before doing any transfers with a SPI slave. It
  602. * will enable and initialize any SPI hardware as necessary, and make
  603. * sure that the SCK line is in the correct idle state. It is not
  604. * allowed to claim the same bus for several slaves without releasing
  605. * the bus in between.
  606. *
  607. * @dev: The SPI slave device
  608. *
  609. * Returns: 0 if the bus was claimed successfully, or a negative value
  610. * if it wasn't.
  611. */
  612. int dm_spi_claim_bus(struct udevice *dev);
  613. /**
  614. * Release the SPI bus
  615. *
  616. * This must be called once for every call to dm_spi_claim_bus() after
  617. * all transfers have finished. It may disable any SPI hardware as
  618. * appropriate.
  619. *
  620. * @slave: The SPI slave device
  621. */
  622. void dm_spi_release_bus(struct udevice *dev);
  623. /**
  624. * SPI transfer
  625. *
  626. * This writes "bitlen" bits out the SPI MOSI port and simultaneously clocks
  627. * "bitlen" bits in the SPI MISO port. That's just the way SPI works.
  628. *
  629. * The source of the outgoing bits is the "dout" parameter and the
  630. * destination of the input bits is the "din" parameter. Note that "dout"
  631. * and "din" can point to the same memory location, in which case the
  632. * input data overwrites the output data (since both are buffered by
  633. * temporary variables, this is OK).
  634. *
  635. * dm_spi_xfer() interface:
  636. * @dev: The SPI slave device which will be sending/receiving the data.
  637. * @bitlen: How many bits to write and read.
  638. * @dout: Pointer to a string of bits to send out. The bits are
  639. * held in a byte array and are sent MSB first.
  640. * @din: Pointer to a string of bits that will be filled in.
  641. * @flags: A bitwise combination of SPI_XFER_* flags.
  642. *
  643. * Returns: 0 on success, not 0 on failure
  644. */
  645. int dm_spi_xfer(struct udevice *dev, unsigned int bitlen,
  646. const void *dout, void *din, unsigned long flags);
  647. /**
  648. * spi_get_mmap() - Get memory-mapped SPI
  649. *
  650. * @dev: SPI slave device to check
  651. * @map_basep: Returns base memory address for mapped SPI
  652. * @map_sizep: Returns size of mapped SPI
  653. * @offsetp: Returns start offset of SPI flash where the map works
  654. * correctly (offsets before this are not visible)
  655. * @return 0 if OK, -ENOSYS if no operation, -EFAULT if memory mapping is not
  656. * available
  657. */
  658. int dm_spi_get_mmap(struct udevice *dev, ulong *map_basep, uint *map_sizep,
  659. uint *offsetp);
  660. /* Access the operations for a SPI device */
  661. #define spi_get_ops(dev) ((struct dm_spi_ops *)(dev)->driver->ops)
  662. #define spi_emul_get_ops(dev) ((struct dm_spi_emul_ops *)(dev)->driver->ops)
  663. #endif /* CONFIG_DM_SPI */
  664. #endif /* _SPI_H_ */