1 /* 2 * Common SPI Interface: Controller-specific definitions 3 * 4 * (C) Copyright 2001 5 * Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com. 6 * 7 * SPDX-License-Identifier: GPL-2.0+ 8 */ 9 10 #ifndef _SPI_H_ 11 #define _SPI_H_ 12 13 #include <common.h> 14 15 /* SPI mode flags */ 16 #define SPI_CPHA BIT(0) /* clock phase */ 17 #define SPI_CPOL BIT(1) /* clock polarity */ 18 #define SPI_MODE_0 (0|0) /* (original MicroWire) */ 19 #define SPI_MODE_1 (0|SPI_CPHA) 20 #define SPI_MODE_2 (SPI_CPOL|0) 21 #define SPI_MODE_3 (SPI_CPOL|SPI_CPHA) 22 #define SPI_CS_HIGH BIT(2) /* CS active high */ 23 #define SPI_LSB_FIRST BIT(3) /* per-word bits-on-wire */ 24 #define SPI_3WIRE BIT(4) /* SI/SO signals shared */ 25 #define SPI_LOOP BIT(5) /* loopback mode */ 26 #define SPI_SLAVE BIT(6) /* slave mode */ 27 #define SPI_PREAMBLE BIT(7) /* Skip preamble bytes */ 28 #define SPI_TX_BYTE BIT(8) /* transmit with 1 wire byte */ 29 #define SPI_TX_DUAL BIT(9) /* transmit with 2 wires */ 30 #define SPI_TX_QUAD BIT(10) /* transmit with 4 wires */ 31 #define SPI_RX_SLOW BIT(11) /* receive with 1 wire slow */ 32 #define SPI_RX_DUAL BIT(12) /* receive with 2 wires */ 33 #define SPI_RX_QUAD BIT(13) /* receive with 4 wires */ 34 #define SPI_DMA_PREPARE BIT(24) /* dma transfer skip waiting idle */ 35 36 /* Header byte that marks the start of the message */ 37 #define SPI_PREAMBLE_END_BYTE 0xec 38 39 #define SPI_DEFAULT_WORDLEN 8 40 41 #ifdef CONFIG_DM_SPI 42 /* TODO(sjg@chromium.org): Remove this and use max_hz from struct spi_slave */ 43 struct dm_spi_bus { 44 uint max_hz; 45 }; 46 47 /** 48 * struct dm_spi_platdata - platform data for all SPI slaves 49 * 50 * This describes a SPI slave, a child device of the SPI bus. To obtain this 51 * struct from a spi_slave, use dev_get_parent_platdata(dev) or 52 * dev_get_parent_platdata(slave->dev). 53 * 54 * This data is immuatable. Each time the device is probed, @max_hz and @mode 55 * will be copied to struct spi_slave. 56 * 57 * @cs: Chip select number (0..n-1) 58 * @max_hz: Maximum bus speed that this slave can tolerate 59 * @mode: SPI mode to use for this device (see SPI mode flags) 60 */ 61 struct dm_spi_slave_platdata { 62 unsigned int cs; 63 uint max_hz; 64 uint mode; 65 }; 66 67 #endif /* CONFIG_DM_SPI */ 68 69 /** 70 * struct spi_slave - Representation of a SPI slave 71 * 72 * For driver model this is the per-child data used by the SPI bus. It can 73 * be accessed using dev_get_parent_priv() on the slave device. The SPI uclass 74 * sets uip per_child_auto_alloc_size to sizeof(struct spi_slave), and the 75 * driver should not override it. Two platform data fields (max_hz and mode) 76 * are copied into this structure to provide an initial value. This allows 77 * them to be changed, since we should never change platform data in drivers. 78 * 79 * If not using driver model, drivers are expected to extend this with 80 * controller-specific data. 81 * 82 * @dev: SPI slave device 83 * @max_hz: Maximum speed for this slave 84 * @speed: Current bus speed. This is 0 until the bus is first 85 * claimed. 86 * @bus: ID of the bus that the slave is attached to. For 87 * driver model this is the sequence number of the SPI 88 * bus (bus->seq) so does not need to be stored 89 * @cs: ID of the chip select connected to the slave. 90 * @mode: SPI mode to use for this slave (see SPI mode flags) 91 * @wordlen: Size of SPI word in number of bits 92 * @max_read_size: If non-zero, the maximum number of bytes which can 93 * be read at once. 94 * @max_write_size: If non-zero, the maximum number of bytes which can 95 * be written at once. 96 * @memory_map: Address of read-only SPI flash access. 97 * @flags: Indication of SPI flags. 98 */ 99 struct spi_slave { 100 #ifdef CONFIG_DM_SPI 101 struct udevice *dev; /* struct spi_slave is dev->parentdata */ 102 uint max_hz; 103 uint speed; 104 #else 105 unsigned int bus; 106 unsigned int cs; 107 #endif 108 uint mode; 109 unsigned int wordlen; 110 unsigned int max_read_size; 111 unsigned int max_write_size; 112 void *memory_map; 113 u8 option; 114 115 u8 flags; 116 #define SPI_XFER_BEGIN BIT(0) /* Assert CS before transfer */ 117 #define SPI_XFER_END BIT(1) /* Deassert CS after transfer */ 118 #define SPI_XFER_ONCE (SPI_XFER_BEGIN | SPI_XFER_END) 119 #define SPI_XFER_MMAP BIT(2) /* Memory Mapped start */ 120 #define SPI_XFER_MMAP_END BIT(3) /* Memory Mapped End */ 121 #define SPI_XFER_PREPARE BIT(7) /* Transfer skip waiting idle */ 122 }; 123 124 /** 125 * Initialization, must be called once on start up. 126 * 127 * TODO: I don't think we really need this. 128 */ 129 void spi_init(void); 130 131 /** 132 * spi_do_alloc_slave - Allocate a new SPI slave (internal) 133 * 134 * Allocate and zero all fields in the spi slave, and set the bus/chip 135 * select. Use the helper macro spi_alloc_slave() to call this. 136 * 137 * @offset: Offset of struct spi_slave within slave structure. 138 * @size: Size of slave structure. 139 * @bus: Bus ID of the slave chip. 140 * @cs: Chip select ID of the slave chip on the specified bus. 141 */ 142 void *spi_do_alloc_slave(int offset, int size, unsigned int bus, 143 unsigned int cs); 144 145 /** 146 * spi_alloc_slave - Allocate a new SPI slave 147 * 148 * Allocate and zero all fields in the spi slave, and set the bus/chip 149 * select. 150 * 151 * @_struct: Name of structure to allocate (e.g. struct tegra_spi). 152 * This structure must contain a member 'struct spi_slave *slave'. 153 * @bus: Bus ID of the slave chip. 154 * @cs: Chip select ID of the slave chip on the specified bus. 155 */ 156 #define spi_alloc_slave(_struct, bus, cs) \ 157 spi_do_alloc_slave(offsetof(_struct, slave), \ 158 sizeof(_struct), bus, cs) 159 160 /** 161 * spi_alloc_slave_base - Allocate a new SPI slave with no private data 162 * 163 * Allocate and zero all fields in the spi slave, and set the bus/chip 164 * select. 165 * 166 * @bus: Bus ID of the slave chip. 167 * @cs: Chip select ID of the slave chip on the specified bus. 168 */ 169 #define spi_alloc_slave_base(bus, cs) \ 170 spi_do_alloc_slave(0, sizeof(struct spi_slave), bus, cs) 171 172 /** 173 * Set up communications parameters for a SPI slave. 174 * 175 * This must be called once for each slave. Note that this function 176 * usually doesn't touch any actual hardware, it only initializes the 177 * contents of spi_slave so that the hardware can be easily 178 * initialized later. 179 * 180 * @bus: Bus ID of the slave chip. 181 * @cs: Chip select ID of the slave chip on the specified bus. 182 * @max_hz: Maximum SCK rate in Hz. 183 * @mode: Clock polarity, clock phase and other parameters. 184 * 185 * Returns: A spi_slave reference that can be used in subsequent SPI 186 * calls, or NULL if one or more of the parameters are not supported. 187 */ 188 struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs, 189 unsigned int max_hz, unsigned int mode); 190 191 /** 192 * Free any memory associated with a SPI slave. 193 * 194 * @slave: The SPI slave 195 */ 196 void spi_free_slave(struct spi_slave *slave); 197 198 /** 199 * Claim the bus and prepare it for communication with a given slave. 200 * 201 * This must be called before doing any transfers with a SPI slave. It 202 * will enable and initialize any SPI hardware as necessary, and make 203 * sure that the SCK line is in the correct idle state. It is not 204 * allowed to claim the same bus for several slaves without releasing 205 * the bus in between. 206 * 207 * @slave: The SPI slave 208 * 209 * Returns: 0 if the bus was claimed successfully, or a negative value 210 * if it wasn't. 211 */ 212 int spi_claim_bus(struct spi_slave *slave); 213 214 /** 215 * Release the SPI bus 216 * 217 * This must be called once for every call to spi_claim_bus() after 218 * all transfers have finished. It may disable any SPI hardware as 219 * appropriate. 220 * 221 * @slave: The SPI slave 222 */ 223 void spi_release_bus(struct spi_slave *slave); 224 225 /** 226 * Set the word length for SPI transactions 227 * 228 * Set the word length (number of bits per word) for SPI transactions. 229 * 230 * @slave: The SPI slave 231 * @wordlen: The number of bits in a word 232 * 233 * Returns: 0 on success, -1 on failure. 234 */ 235 int spi_set_wordlen(struct spi_slave *slave, unsigned int wordlen); 236 237 /** 238 * SPI transfer (optional if mem_ops is used) 239 * 240 * This writes "bitlen" bits out the SPI MOSI port and simultaneously clocks 241 * "bitlen" bits in the SPI MISO port. That's just the way SPI works. 242 * 243 * The source of the outgoing bits is the "dout" parameter and the 244 * destination of the input bits is the "din" parameter. Note that "dout" 245 * and "din" can point to the same memory location, in which case the 246 * input data overwrites the output data (since both are buffered by 247 * temporary variables, this is OK). 248 * 249 * spi_xfer() interface: 250 * @slave: The SPI slave which will be sending/receiving the data. 251 * @bitlen: How many bits to write and read. 252 * @dout: Pointer to a string of bits to send out. The bits are 253 * held in a byte array and are sent MSB first. 254 * @din: Pointer to a string of bits that will be filled in. 255 * @flags: A bitwise combination of SPI_XFER_* flags. 256 * 257 * Returns: 0 on success, not 0 on failure 258 */ 259 int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout, 260 void *din, unsigned long flags); 261 262 /** 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); 281 282 /* Copy memory mapped data */ 283 void spi_flash_copy_mmap(void *data, void *offset, size_t len); 284 285 /** 286 * Determine if a SPI chipselect is valid. 287 * This function is provided by the board if the low-level SPI driver 288 * needs it to determine if a given chipselect is actually valid. 289 * 290 * Returns: 1 if bus:cs identifies a valid chip on this board, 0 291 * otherwise. 292 */ 293 int spi_cs_is_valid(unsigned int bus, unsigned int cs); 294 295 #ifndef CONFIG_DM_SPI 296 /** 297 * Activate a SPI chipselect. 298 * This function is provided by the board code when using a driver 299 * that can't control its chipselects automatically (e.g. 300 * common/soft_spi.c). When called, it should activate the chip select 301 * to the device identified by "slave". 302 */ 303 void spi_cs_activate(struct spi_slave *slave); 304 305 /** 306 * Deactivate a SPI chipselect. 307 * This function is provided by the board code when using a driver 308 * that can't control its chipselects automatically (e.g. 309 * common/soft_spi.c). When called, it should deactivate the chip 310 * select to the device identified by "slave". 311 */ 312 void spi_cs_deactivate(struct spi_slave *slave); 313 314 /** 315 * Set transfer speed. 316 * This sets a new speed to be applied for next spi_xfer(). 317 * @slave: The SPI slave 318 * @hz: The transfer speed 319 */ 320 void spi_set_speed(struct spi_slave *slave, uint hz); 321 #endif 322 323 /** 324 * Write 8 bits, then read 8 bits. 325 * @slave: The SPI slave we're communicating with 326 * @byte: Byte to be written 327 * 328 * Returns: The value that was read, or a negative value on error. 329 * 330 * TODO: This function probably shouldn't be inlined. 331 */ 332 static inline int spi_w8r8(struct spi_slave *slave, unsigned char byte) 333 { 334 unsigned char dout[2]; 335 unsigned char din[2]; 336 int ret; 337 338 dout[0] = byte; 339 dout[1] = 0; 340 341 ret = spi_xfer(slave, 16, dout, din, SPI_XFER_BEGIN | SPI_XFER_END); 342 return ret < 0 ? ret : din[1]; 343 } 344 345 #ifdef CONFIG_DM_SPI 346 347 /** 348 * struct spi_cs_info - Information about a bus chip select 349 * 350 * @dev: Connected device, or NULL if none 351 */ 352 struct spi_cs_info { 353 struct udevice *dev; 354 }; 355 356 /** 357 * struct struct dm_spi_ops - Driver model SPI operations 358 * 359 * The uclass interface is implemented by all SPI devices which use 360 * driver model. 361 */ 362 struct dm_spi_ops { 363 /** 364 * Claim the bus and prepare it for communication. 365 * 366 * The device provided is the slave device. It's parent controller 367 * will be used to provide the communication. 368 * 369 * This must be called before doing any transfers with a SPI slave. It 370 * will enable and initialize any SPI hardware as necessary, and make 371 * sure that the SCK line is in the correct idle state. It is not 372 * allowed to claim the same bus for several slaves without releasing 373 * the bus in between. 374 * 375 * @dev: The SPI slave 376 * 377 * Returns: 0 if the bus was claimed successfully, or a negative value 378 * if it wasn't. 379 */ 380 int (*claim_bus)(struct udevice *dev); 381 382 /** 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 /** 394 * Set the word length for SPI transactions 395 * 396 * Set the word length (number of bits per word) for SPI transactions. 397 * 398 * @bus: The SPI slave 399 * @wordlen: The number of bits in a word 400 * 401 * Returns: 0 on success, -ve on failure. 402 */ 403 int (*set_wordlen)(struct udevice *dev, unsigned int wordlen); 404 405 /** 406 * SPI transfer 407 * 408 * This writes "bitlen" bits out the SPI MOSI port and simultaneously 409 * clocks "bitlen" bits in the SPI MISO port. That's just the way SPI 410 * works. 411 * 412 * The source of the outgoing bits is the "dout" parameter and the 413 * destination of the input bits is the "din" parameter. Note that 414 * "dout" and "din" can point to the same memory location, in which 415 * case the input data overwrites the output data (since both are 416 * buffered by temporary variables, this is OK). 417 * 418 * spi_xfer() interface: 419 * @dev: The slave device to communicate with 420 * @bitlen: How many bits to write and read. 421 * @dout: Pointer to a string of bits to send out. The bits are 422 * held in a byte array and are sent MSB first. 423 * @din: Pointer to a string of bits that will be filled in. 424 * @flags: A bitwise combination of SPI_XFER_* flags. 425 * 426 * Returns: 0 on success, not -1 on failure 427 */ 428 int (*xfer)(struct udevice *dev, unsigned int bitlen, const void *dout, 429 void *din, unsigned long flags); 430 431 /** 432 * Optimized handlers for SPI memory-like operations. 433 * 434 * Optimized/dedicated operations for interactions with SPI memory. This 435 * field is optional and should only be implemented if the controller 436 * has native support for memory like operations. 437 */ 438 const struct spi_controller_mem_ops *mem_ops; 439 440 /** 441 * Set transfer speed. 442 * This sets a new speed to be applied for next spi_xfer(). 443 * @bus: The SPI bus 444 * @hz: The transfer speed 445 * @return 0 if OK, -ve on error 446 */ 447 int (*set_speed)(struct udevice *bus, uint hz); 448 449 /** 450 * Set the SPI mode/flags 451 * 452 * It is unclear if we want to set speed and mode together instead 453 * of separately. 454 * 455 * @bus: The SPI bus 456 * @mode: Requested SPI mode (SPI_... flags) 457 * @return 0 if OK, -ve on error 458 */ 459 int (*set_mode)(struct udevice *bus, uint mode); 460 461 /** 462 * Get information on a chip select 463 * 464 * This is only called when the SPI uclass does not know about a 465 * chip select, i.e. it has no attached device. It gives the driver 466 * a chance to allow activity on that chip select even so. 467 * 468 * @bus: The SPI bus 469 * @cs: The chip select (0..n-1) 470 * @info: Returns information about the chip select, if valid. 471 * On entry info->dev is NULL 472 * @return 0 if OK (and @info is set up), -ENODEV if the chip select 473 * is invalid, other -ve value on error 474 */ 475 int (*cs_info)(struct udevice *bus, uint cs, struct spi_cs_info *info); 476 477 /** 478 * get_mmap() - Get memory-mapped SPI 479 * 480 * @dev: The SPI flash slave device 481 * @map_basep: Returns base memory address for mapped SPI 482 * @map_sizep: Returns size of mapped SPI 483 * @offsetp: Returns start offset of SPI flash where the map works 484 * correctly (offsets before this are not visible) 485 * @return 0 if OK, -EFAULT if memory mapping is not available 486 */ 487 int (*get_mmap)(struct udevice *dev, ulong *map_basep, 488 uint *map_sizep, uint *offsetp); 489 }; 490 491 struct dm_spi_emul_ops { 492 /** 493 * SPI transfer 494 * 495 * This writes "bitlen" bits out the SPI MOSI port and simultaneously 496 * clocks "bitlen" bits in the SPI MISO port. That's just the way SPI 497 * works. Here the device is a slave. 498 * 499 * The source of the outgoing bits is the "dout" parameter and the 500 * destination of the input bits is the "din" parameter. Note that 501 * "dout" and "din" can point to the same memory location, in which 502 * case the input data overwrites the output data (since both are 503 * buffered by temporary variables, this is OK). 504 * 505 * spi_xfer() interface: 506 * @slave: The SPI slave which will be sending/receiving the data. 507 * @bitlen: How many bits to write and read. 508 * @dout: Pointer to a string of bits sent to the device. The 509 * bits are held in a byte array and are sent MSB first. 510 * @din: Pointer to a string of bits that will be sent back to 511 * the master. 512 * @flags: A bitwise combination of SPI_XFER_* flags. 513 * 514 * Returns: 0 on success, not -1 on failure 515 */ 516 int (*xfer)(struct udevice *slave, unsigned int bitlen, 517 const void *dout, void *din, unsigned long flags); 518 }; 519 520 /** 521 * spi_find_bus_and_cs() - Find bus and slave devices by number 522 * 523 * Given a bus number and chip select, this finds the corresponding bus 524 * device and slave device. Neither device is activated by this function, 525 * although they may have been activated previously. 526 * 527 * @busnum: SPI bus number 528 * @cs: Chip select to look for 529 * @busp: Returns bus device 530 * @devp: Return slave device 531 * @return 0 if found, -ENODEV on error 532 */ 533 int spi_find_bus_and_cs(int busnum, int cs, struct udevice **busp, 534 struct udevice **devp); 535 536 /** 537 * spi_get_bus_and_cs() - Find and activate bus and slave devices by number 538 * 539 * Given a bus number and chip select, this finds the corresponding bus 540 * device and slave device. 541 * 542 * If no such slave exists, and drv_name is not NULL, then a new slave device 543 * is automatically bound on this chip select with requested speed and mode. 544 * 545 * Ths new slave device is probed ready for use with the speed and mode 546 * from platdata when available or the requested values. 547 * 548 * @busnum: SPI bus number 549 * @cs: Chip select to look for 550 * @speed: SPI speed to use for this slave when not available in platdata 551 * @mode: SPI mode to use for this slave when not available in platdata 552 * @drv_name: Name of driver to attach to this chip select 553 * @dev_name: Name of the new device thus created 554 * @busp: Returns bus device 555 * @devp: Return slave device 556 * @return 0 if found, -ve on error 557 */ 558 int spi_get_bus_and_cs(int busnum, int cs, int speed, int mode, 559 const char *drv_name, const char *dev_name, 560 struct udevice **busp, struct spi_slave **devp); 561 562 /** 563 * spi_chip_select() - Get the chip select for a slave 564 * 565 * @return the chip select this slave is attached to 566 */ 567 int spi_chip_select(struct udevice *slave); 568 569 /** 570 * spi_find_chip_select() - Find the slave attached to chip select 571 * 572 * @bus: SPI bus to search 573 * @cs: Chip select to look for 574 * @devp: Returns the slave device if found 575 * @return 0 if found, -EINVAL if cs is invalid, -ENODEV if no device attached, 576 * other -ve value on error 577 */ 578 int spi_find_chip_select(struct udevice *bus, int cs, struct udevice **devp); 579 580 /** 581 * spi_slave_ofdata_to_platdata() - decode standard SPI platform data 582 * 583 * This decodes the speed and mode for a slave from a device tree node 584 * 585 * @blob: Device tree blob 586 * @node: Node offset to read from 587 * @plat: Place to put the decoded information 588 */ 589 int spi_slave_ofdata_to_platdata(struct udevice *dev, 590 struct dm_spi_slave_platdata *plat); 591 592 /** 593 * spi_cs_info() - Check information on a chip select 594 * 595 * This checks a particular chip select on a bus to see if it has a device 596 * attached, or is even valid. 597 * 598 * @bus: The SPI bus 599 * @cs: The chip select (0..n-1) 600 * @info: Returns information about the chip select, if valid 601 * @return 0 if OK (and @info is set up), -ENODEV if the chip select 602 * is invalid, other -ve value on error 603 */ 604 int spi_cs_info(struct udevice *bus, uint cs, struct spi_cs_info *info); 605 606 struct sandbox_state; 607 608 /** 609 * sandbox_spi_get_emul() - get an emulator for a SPI slave 610 * 611 * This provides a way to attach an emulated SPI device to a particular SPI 612 * slave, so that xfer() operations on the slave will be handled by the 613 * emulator. If a emulator already exists on that chip select it is returned. 614 * Otherwise one is created. 615 * 616 * @state: Sandbox state 617 * @bus: SPI bus requesting the emulator 618 * @slave: SPI slave device requesting the emulator 619 * @emuip: Returns pointer to emulator 620 * @return 0 if OK, -ve on error 621 */ 622 int sandbox_spi_get_emul(struct sandbox_state *state, 623 struct udevice *bus, struct udevice *slave, 624 struct udevice **emulp); 625 626 /** 627 * Claim the bus and prepare it for communication with a given slave. 628 * 629 * This must be called before doing any transfers with a SPI slave. It 630 * will enable and initialize any SPI hardware as necessary, and make 631 * sure that the SCK line is in the correct idle state. It is not 632 * allowed to claim the same bus for several slaves without releasing 633 * the bus in between. 634 * 635 * @dev: The SPI slave device 636 * 637 * Returns: 0 if the bus was claimed successfully, or a negative value 638 * if it wasn't. 639 */ 640 int dm_spi_claim_bus(struct udevice *dev); 641 642 /** 643 * Release the SPI bus 644 * 645 * This must be called once for every call to dm_spi_claim_bus() after 646 * all transfers have finished. It may disable any SPI hardware as 647 * appropriate. 648 * 649 * @slave: The SPI slave device 650 */ 651 void dm_spi_release_bus(struct udevice *dev); 652 653 /** 654 * SPI transfer 655 * 656 * This writes "bitlen" bits out the SPI MOSI port and simultaneously clocks 657 * "bitlen" bits in the SPI MISO port. That's just the way SPI works. 658 * 659 * The source of the outgoing bits is the "dout" parameter and the 660 * destination of the input bits is the "din" parameter. Note that "dout" 661 * and "din" can point to the same memory location, in which case the 662 * input data overwrites the output data (since both are buffered by 663 * temporary variables, this is OK). 664 * 665 * dm_spi_xfer() interface: 666 * @dev: The SPI slave device which will be sending/receiving the data. 667 * @bitlen: How many bits to write and read. 668 * @dout: Pointer to a string of bits to send out. The bits are 669 * held in a byte array and are sent MSB first. 670 * @din: Pointer to a string of bits that will be filled in. 671 * @flags: A bitwise combination of SPI_XFER_* flags. 672 * 673 * Returns: 0 on success, not 0 on failure 674 */ 675 int dm_spi_xfer(struct udevice *dev, unsigned int bitlen, 676 const void *dout, void *din, unsigned long flags); 677 678 /** 679 * spi_get_mmap() - Get memory-mapped SPI 680 * 681 * @dev: SPI slave device to check 682 * @map_basep: Returns base memory address for mapped SPI 683 * @map_sizep: Returns size of mapped SPI 684 * @offsetp: Returns start offset of SPI flash where the map works 685 * correctly (offsets before this are not visible) 686 * @return 0 if OK, -ENOSYS if no operation, -EFAULT if memory mapping is not 687 * available 688 */ 689 int dm_spi_get_mmap(struct udevice *dev, ulong *map_basep, uint *map_sizep, 690 uint *offsetp); 691 692 /* Access the operations for a SPI device */ 693 #define spi_get_ops(dev) ((struct dm_spi_ops *)(dev)->driver->ops) 694 #define spi_emul_get_ops(dev) ((struct dm_spi_emul_ops *)(dev)->driver->ops) 695 #endif /* CONFIG_DM_SPI */ 696 697 #endif /* _SPI_H_ */ 698