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_TX_OCTAL BIT(14) /* transmit with 8 wires */ 35 #define SPI_RX_OCTAL BIT(15) /* receive with 8 wires */ 36 #define SPI_DMA_PREPARE BIT(24) /* dma transfer skip waiting idle */ 37 38 /* Header byte that marks the start of the message */ 39 #define SPI_PREAMBLE_END_BYTE 0xec 40 41 #define SPI_DEFAULT_WORDLEN 8 42 43 #ifdef CONFIG_DM_SPI 44 /* TODO(sjg@chromium.org): Remove this and use max_hz from struct spi_slave */ 45 struct dm_spi_bus { 46 uint max_hz; 47 }; 48 49 /** 50 * struct dm_spi_platdata - platform data for all SPI slaves 51 * 52 * This describes a SPI slave, a child device of the SPI bus. To obtain this 53 * struct from a spi_slave, use dev_get_parent_platdata(dev) or 54 * dev_get_parent_platdata(slave->dev). 55 * 56 * This data is immuatable. Each time the device is probed, @max_hz and @mode 57 * will be copied to struct spi_slave. 58 * 59 * @cs: Chip select number (0..n-1) 60 * @max_hz: Maximum bus speed that this slave can tolerate 61 * @mode: SPI mode to use for this device (see SPI mode flags) 62 */ 63 struct dm_spi_slave_platdata { 64 unsigned int cs; 65 uint max_hz; 66 uint mode; 67 }; 68 69 #endif /* CONFIG_DM_SPI */ 70 71 /** 72 * struct spi_slave - Representation of a SPI slave 73 * 74 * For driver model this is the per-child data used by the SPI bus. It can 75 * be accessed using dev_get_parent_priv() on the slave device. The SPI uclass 76 * sets uip per_child_auto_alloc_size to sizeof(struct spi_slave), and the 77 * driver should not override it. Two platform data fields (max_hz and mode) 78 * are copied into this structure to provide an initial value. This allows 79 * them to be changed, since we should never change platform data in drivers. 80 * 81 * If not using driver model, drivers are expected to extend this with 82 * controller-specific data. 83 * 84 * @dev: SPI slave device 85 * @max_hz: Maximum speed for this slave 86 * @speed: Current bus speed. This is 0 until the bus is first 87 * claimed. 88 * @bus: ID of the bus that the slave is attached to. For 89 * driver model this is the sequence number of the SPI 90 * bus (bus->seq) so does not need to be stored 91 * @cs: ID of the chip select connected to the slave. 92 * @mode: SPI mode to use for this slave (see SPI mode flags) 93 * @wordlen: Size of SPI word in number of bits 94 * @max_read_size: If non-zero, the maximum number of bytes which can 95 * be read at once. 96 * @max_write_size: If non-zero, the maximum number of bytes which can 97 * be written at once. 98 * @memory_map: Address of read-only SPI flash access. 99 * @flags: Indication of SPI flags. 100 */ 101 struct spi_slave { 102 #ifdef CONFIG_DM_SPI 103 struct udevice *dev; /* struct spi_slave is dev->parentdata */ 104 uint max_hz; 105 uint speed; 106 #else 107 unsigned int bus; 108 unsigned int cs; 109 #endif 110 uint mode; 111 unsigned int wordlen; 112 unsigned int max_read_size; 113 unsigned int max_write_size; 114 void *memory_map; 115 u8 option; 116 117 u8 flags; 118 #define SPI_XFER_BEGIN BIT(0) /* Assert CS before transfer */ 119 #define SPI_XFER_END BIT(1) /* Deassert CS after transfer */ 120 #define SPI_XFER_ONCE (SPI_XFER_BEGIN | SPI_XFER_END) 121 #define SPI_XFER_MMAP BIT(2) /* Memory Mapped start */ 122 #define SPI_XFER_MMAP_END BIT(3) /* Memory Mapped End */ 123 #define SPI_XFER_PREPARE BIT(7) /* Transfer skip waiting idle */ 124 }; 125 126 /** 127 * Initialization, must be called once on start up. 128 * 129 * TODO: I don't think we really need this. 130 */ 131 void spi_init(void); 132 133 /** 134 * spi_do_alloc_slave - Allocate a new SPI slave (internal) 135 * 136 * Allocate and zero all fields in the spi slave, and set the bus/chip 137 * select. Use the helper macro spi_alloc_slave() to call this. 138 * 139 * @offset: Offset of struct spi_slave within slave structure. 140 * @size: Size of slave structure. 141 * @bus: Bus ID of the slave chip. 142 * @cs: Chip select ID of the slave chip on the specified bus. 143 */ 144 void *spi_do_alloc_slave(int offset, int size, unsigned int bus, 145 unsigned int cs); 146 147 /** 148 * spi_alloc_slave - Allocate a new SPI slave 149 * 150 * Allocate and zero all fields in the spi slave, and set the bus/chip 151 * select. 152 * 153 * @_struct: Name of structure to allocate (e.g. struct tegra_spi). 154 * This structure must contain a member 'struct spi_slave *slave'. 155 * @bus: Bus ID of the slave chip. 156 * @cs: Chip select ID of the slave chip on the specified bus. 157 */ 158 #define spi_alloc_slave(_struct, bus, cs) \ 159 spi_do_alloc_slave(offsetof(_struct, slave), \ 160 sizeof(_struct), bus, cs) 161 162 /** 163 * spi_alloc_slave_base - Allocate a new SPI slave with no private data 164 * 165 * Allocate and zero all fields in the spi slave, and set the bus/chip 166 * select. 167 * 168 * @bus: Bus ID of the slave chip. 169 * @cs: Chip select ID of the slave chip on the specified bus. 170 */ 171 #define spi_alloc_slave_base(bus, cs) \ 172 spi_do_alloc_slave(0, sizeof(struct spi_slave), bus, cs) 173 174 /** 175 * Set up communications parameters for a SPI slave. 176 * 177 * This must be called once for each slave. Note that this function 178 * usually doesn't touch any actual hardware, it only initializes the 179 * contents of spi_slave so that the hardware can be easily 180 * initialized later. 181 * 182 * @bus: Bus ID of the slave chip. 183 * @cs: Chip select ID of the slave chip on the specified bus. 184 * @max_hz: Maximum SCK rate in Hz. 185 * @mode: Clock polarity, clock phase and other parameters. 186 * 187 * Returns: A spi_slave reference that can be used in subsequent SPI 188 * calls, or NULL if one or more of the parameters are not supported. 189 */ 190 struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs, 191 unsigned int max_hz, unsigned int mode); 192 193 /** 194 * Free any memory associated with a SPI slave. 195 * 196 * @slave: The SPI slave 197 */ 198 void spi_free_slave(struct spi_slave *slave); 199 200 /** 201 * Claim the bus and prepare it for communication with a given slave. 202 * 203 * This must be called before doing any transfers with a SPI slave. It 204 * will enable and initialize any SPI hardware as necessary, and make 205 * sure that the SCK line is in the correct idle state. It is not 206 * allowed to claim the same bus for several slaves without releasing 207 * the bus in between. 208 * 209 * @slave: The SPI slave 210 * 211 * Returns: 0 if the bus was claimed successfully, or a negative value 212 * if it wasn't. 213 */ 214 int spi_claim_bus(struct spi_slave *slave); 215 216 /** 217 * Release the SPI bus 218 * 219 * This must be called once for every call to spi_claim_bus() after 220 * all transfers have finished. It may disable any SPI hardware as 221 * appropriate. 222 * 223 * @slave: The SPI slave 224 */ 225 void spi_release_bus(struct spi_slave *slave); 226 227 /** 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 /** 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 /** 265 * spi_write_then_read - SPI synchronous write followed by read 266 * 267 * This performs a half duplex transaction in which the first transaction 268 * is to send the opcode and if the length of buf is non-zero then it start 269 * the second transaction as tx or rx based on the need from respective slave. 270 * 271 * @slave: The SPI slave device with which opcode/data will be exchanged 272 * @opcode: opcode used for specific transfer 273 * @n_opcode: size of opcode, in bytes 274 * @txbuf: buffer into which data to be written 275 * @rxbuf: buffer into which data will be read 276 * @n_buf: size of buf (whether it's [tx|rx]buf), in bytes 277 * 278 * Returns: 0 on success, not 0 on failure 279 */ 280 int spi_write_then_read(struct spi_slave *slave, const u8 *opcode, 281 size_t n_opcode, const u8 *txbuf, u8 *rxbuf, 282 size_t n_buf); 283 284 /* Copy memory mapped data */ 285 void spi_flash_copy_mmap(void *data, void *offset, size_t len); 286 287 /** 288 * Determine if a SPI chipselect is valid. 289 * This function is provided by the board if the low-level SPI driver 290 * needs it to determine if a given chipselect is actually valid. 291 * 292 * Returns: 1 if bus:cs identifies a valid chip on this board, 0 293 * otherwise. 294 */ 295 int spi_cs_is_valid(unsigned int bus, unsigned int cs); 296 297 #ifndef CONFIG_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 /** 308 * Deactivate a SPI chipselect. 309 * This function is provided by the board code when using a driver 310 * that can't control its chipselects automatically (e.g. 311 * common/soft_spi.c). When called, it should deactivate the chip 312 * select to the device identified by "slave". 313 */ 314 void spi_cs_deactivate(struct spi_slave *slave); 315 316 /** 317 * Set transfer speed. 318 * This sets a new speed to be applied for next spi_xfer(). 319 * @slave: The SPI slave 320 * @hz: The transfer speed 321 */ 322 void spi_set_speed(struct spi_slave *slave, uint hz); 323 #endif 324 325 /** 326 * Write 8 bits, then read 8 bits. 327 * @slave: The SPI slave we're communicating with 328 * @byte: Byte to be written 329 * 330 * Returns: The value that was read, or a negative value on error. 331 * 332 * TODO: This function probably shouldn't be inlined. 333 */ 334 static inline int spi_w8r8(struct spi_slave *slave, unsigned char byte) 335 { 336 unsigned char dout[2]; 337 unsigned char din[2]; 338 int ret; 339 340 dout[0] = byte; 341 dout[1] = 0; 342 343 ret = spi_xfer(slave, 16, dout, din, SPI_XFER_BEGIN | SPI_XFER_END); 344 return ret < 0 ? ret : din[1]; 345 } 346 347 #ifdef CONFIG_DM_SPI 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 /** 359 * struct struct dm_spi_ops - Driver model SPI operations 360 * 361 * The uclass interface is implemented by all SPI devices which use 362 * driver model. 363 */ 364 struct dm_spi_ops { 365 /** 366 * Claim the bus and prepare it for communication. 367 * 368 * The device provided is the slave device. It's parent controller 369 * will be used to provide the communication. 370 * 371 * This must be called before doing any transfers with a SPI slave. It 372 * will enable and initialize any SPI hardware as necessary, and make 373 * sure that the SCK line is in the correct idle state. It is not 374 * allowed to claim the same bus for several slaves without releasing 375 * the bus in between. 376 * 377 * @dev: The SPI slave 378 * 379 * Returns: 0 if the bus was claimed successfully, or a negative value 380 * if it wasn't. 381 */ 382 int (*claim_bus)(struct udevice *dev); 383 384 /** 385 * Release the SPI bus 386 * 387 * This must be called once for every call to spi_claim_bus() after 388 * all transfers have finished. It may disable any SPI hardware as 389 * appropriate. 390 * 391 * @dev: The SPI slave 392 */ 393 int (*release_bus)(struct udevice *dev); 394 395 /** 396 * Set the word length for SPI transactions 397 * 398 * Set the word length (number of bits per word) for SPI transactions. 399 * 400 * @bus: The SPI slave 401 * @wordlen: The number of bits in a word 402 * 403 * Returns: 0 on success, -ve on failure. 404 */ 405 int (*set_wordlen)(struct udevice *dev, unsigned int wordlen); 406 407 /** 408 * SPI transfer 409 * 410 * This writes "bitlen" bits out the SPI MOSI port and simultaneously 411 * clocks "bitlen" bits in the SPI MISO port. That's just the way SPI 412 * works. 413 * 414 * The source of the outgoing bits is the "dout" parameter and the 415 * destination of the input bits is the "din" parameter. Note that 416 * "dout" and "din" can point to the same memory location, in which 417 * case the input data overwrites the output data (since both are 418 * buffered by temporary variables, this is OK). 419 * 420 * spi_xfer() interface: 421 * @dev: The slave device to communicate with 422 * @bitlen: How many bits to write and read. 423 * @dout: Pointer to a string of bits to send out. The bits are 424 * held in a byte array and are sent MSB first. 425 * @din: Pointer to a string of bits that will be filled in. 426 * @flags: A bitwise combination of SPI_XFER_* flags. 427 * 428 * Returns: 0 on success, not -1 on failure 429 */ 430 int (*xfer)(struct udevice *dev, unsigned int bitlen, const void *dout, 431 void *din, unsigned long flags); 432 433 /** 434 * Optimized handlers for SPI memory-like operations. 435 * 436 * Optimized/dedicated operations for interactions with SPI memory. This 437 * field is optional and should only be implemented if the controller 438 * has native support for memory like operations. 439 */ 440 const struct spi_controller_mem_ops *mem_ops; 441 442 /** 443 * Set transfer speed. 444 * This sets a new speed to be applied for next spi_xfer(). 445 * @bus: The SPI bus 446 * @hz: The transfer speed 447 * @return 0 if OK, -ve on error 448 */ 449 int (*set_speed)(struct udevice *bus, uint hz); 450 451 /** 452 * Set the SPI mode/flags 453 * 454 * It is unclear if we want to set speed and mode together instead 455 * of separately. 456 * 457 * @bus: The SPI bus 458 * @mode: Requested SPI mode (SPI_... flags) 459 * @return 0 if OK, -ve on error 460 */ 461 int (*set_mode)(struct udevice *bus, uint mode); 462 463 /** 464 * Get information on a chip select 465 * 466 * This is only called when the SPI uclass does not know about a 467 * chip select, i.e. it has no attached device. It gives the driver 468 * a chance to allow activity on that chip select even so. 469 * 470 * @bus: The SPI bus 471 * @cs: The chip select (0..n-1) 472 * @info: Returns information about the chip select, if valid. 473 * On entry info->dev is NULL 474 * @return 0 if OK (and @info is set up), -ENODEV if the chip select 475 * is invalid, other -ve value on error 476 */ 477 int (*cs_info)(struct udevice *bus, uint cs, struct spi_cs_info *info); 478 479 /** 480 * get_mmap() - Get memory-mapped SPI 481 * 482 * @dev: The SPI flash slave device 483 * @map_basep: Returns base memory address for mapped SPI 484 * @map_sizep: Returns size of mapped SPI 485 * @offsetp: Returns start offset of SPI flash where the map works 486 * correctly (offsets before this are not visible) 487 * @return 0 if OK, -EFAULT if memory mapping is not available 488 */ 489 int (*get_mmap)(struct udevice *dev, ulong *map_basep, 490 uint *map_sizep, uint *offsetp); 491 }; 492 493 struct dm_spi_emul_ops { 494 /** 495 * SPI transfer 496 * 497 * This writes "bitlen" bits out the SPI MOSI port and simultaneously 498 * clocks "bitlen" bits in the SPI MISO port. That's just the way SPI 499 * works. Here the device is a slave. 500 * 501 * The source of the outgoing bits is the "dout" parameter and the 502 * destination of the input bits is the "din" parameter. Note that 503 * "dout" and "din" can point to the same memory location, in which 504 * case the input data overwrites the output data (since both are 505 * buffered by temporary variables, this is OK). 506 * 507 * spi_xfer() interface: 508 * @slave: The SPI slave which will be sending/receiving the data. 509 * @bitlen: How many bits to write and read. 510 * @dout: Pointer to a string of bits sent to the device. The 511 * bits are held in a byte array and are sent MSB first. 512 * @din: Pointer to a string of bits that will be sent back to 513 * the master. 514 * @flags: A bitwise combination of SPI_XFER_* flags. 515 * 516 * Returns: 0 on success, not -1 on failure 517 */ 518 int (*xfer)(struct udevice *slave, unsigned int bitlen, 519 const void *dout, void *din, unsigned long flags); 520 }; 521 522 /** 523 * spi_find_bus_and_cs() - Find bus and slave devices by number 524 * 525 * Given a bus number and chip select, this finds the corresponding bus 526 * device and slave device. Neither device is activated by this function, 527 * although they may have been activated previously. 528 * 529 * @busnum: SPI bus number 530 * @cs: Chip select to look for 531 * @busp: Returns bus device 532 * @devp: Return slave device 533 * @return 0 if found, -ENODEV on error 534 */ 535 int spi_find_bus_and_cs(int busnum, int cs, struct udevice **busp, 536 struct udevice **devp); 537 538 /** 539 * spi_get_bus_and_cs() - Find and activate bus and slave devices by number 540 * 541 * Given a bus number and chip select, this finds the corresponding bus 542 * device and slave device. 543 * 544 * If no such slave exists, and drv_name is not NULL, then a new slave device 545 * is automatically bound on this chip select with requested speed and mode. 546 * 547 * Ths new slave device is probed ready for use with the speed and mode 548 * from platdata when available or the requested values. 549 * 550 * @busnum: SPI bus number 551 * @cs: Chip select to look for 552 * @speed: SPI speed to use for this slave when not available in platdata 553 * @mode: SPI mode to use for this slave when not available in platdata 554 * @drv_name: Name of driver to attach to this chip select 555 * @dev_name: Name of the new device thus created 556 * @busp: Returns bus device 557 * @devp: Return slave device 558 * @return 0 if found, -ve on error 559 */ 560 int spi_get_bus_and_cs(int busnum, int cs, int speed, int mode, 561 const char *drv_name, const char *dev_name, 562 struct udevice **busp, struct spi_slave **devp); 563 564 /** 565 * spi_chip_select() - Get the chip select for a slave 566 * 567 * @return the chip select this slave is attached to 568 */ 569 int spi_chip_select(struct udevice *slave); 570 571 /** 572 * spi_find_chip_select() - Find the slave attached to chip select 573 * 574 * @bus: SPI bus to search 575 * @cs: Chip select to look for 576 * @devp: Returns the slave device if found 577 * @return 0 if found, -EINVAL if cs is invalid, -ENODEV if no device attached, 578 * other -ve value on error 579 */ 580 int spi_find_chip_select(struct udevice *bus, int cs, struct udevice **devp); 581 582 /** 583 * spi_slave_ofdata_to_platdata() - decode standard SPI platform data 584 * 585 * This decodes the speed and mode for a slave from a device tree node 586 * 587 * @blob: Device tree blob 588 * @node: Node offset to read from 589 * @plat: Place to put the decoded information 590 */ 591 int spi_slave_ofdata_to_platdata(struct udevice *dev, 592 struct dm_spi_slave_platdata *plat); 593 594 /** 595 * spi_cs_info() - Check information on a chip select 596 * 597 * This checks a particular chip select on a bus to see if it has a device 598 * attached, or is even valid. 599 * 600 * @bus: The SPI bus 601 * @cs: The chip select (0..n-1) 602 * @info: Returns information about the chip select, if valid 603 * @return 0 if OK (and @info is set up), -ENODEV if the chip select 604 * is invalid, other -ve value on error 605 */ 606 int spi_cs_info(struct udevice *bus, uint cs, struct spi_cs_info *info); 607 608 struct sandbox_state; 609 610 /** 611 * sandbox_spi_get_emul() - get an emulator for a SPI slave 612 * 613 * This provides a way to attach an emulated SPI device to a particular SPI 614 * slave, so that xfer() operations on the slave will be handled by the 615 * emulator. If a emulator already exists on that chip select it is returned. 616 * Otherwise one is created. 617 * 618 * @state: Sandbox state 619 * @bus: SPI bus requesting the emulator 620 * @slave: SPI slave device requesting the emulator 621 * @emuip: Returns pointer to emulator 622 * @return 0 if OK, -ve on error 623 */ 624 int sandbox_spi_get_emul(struct sandbox_state *state, 625 struct udevice *bus, struct udevice *slave, 626 struct udevice **emulp); 627 628 /** 629 * Claim the bus and prepare it for communication with a given slave. 630 * 631 * This must be called before doing any transfers with a SPI slave. It 632 * will enable and initialize any SPI hardware as necessary, and make 633 * sure that the SCK line is in the correct idle state. It is not 634 * allowed to claim the same bus for several slaves without releasing 635 * the bus in between. 636 * 637 * @dev: The SPI slave device 638 * 639 * Returns: 0 if the bus was claimed successfully, or a negative value 640 * if it wasn't. 641 */ 642 int dm_spi_claim_bus(struct udevice *dev); 643 644 /** 645 * Release the SPI bus 646 * 647 * This must be called once for every call to dm_spi_claim_bus() after 648 * all transfers have finished. It may disable any SPI hardware as 649 * appropriate. 650 * 651 * @slave: The SPI slave device 652 */ 653 void dm_spi_release_bus(struct udevice *dev); 654 655 /** 656 * SPI transfer 657 * 658 * This writes "bitlen" bits out the SPI MOSI port and simultaneously clocks 659 * "bitlen" bits in the SPI MISO port. That's just the way SPI works. 660 * 661 * The source of the outgoing bits is the "dout" parameter and the 662 * destination of the input bits is the "din" parameter. Note that "dout" 663 * and "din" can point to the same memory location, in which case the 664 * input data overwrites the output data (since both are buffered by 665 * temporary variables, this is OK). 666 * 667 * dm_spi_xfer() interface: 668 * @dev: The SPI slave device which will be sending/receiving the data. 669 * @bitlen: How many bits to write and read. 670 * @dout: Pointer to a string of bits to send out. The bits are 671 * held in a byte array and are sent MSB first. 672 * @din: Pointer to a string of bits that will be filled in. 673 * @flags: A bitwise combination of SPI_XFER_* flags. 674 * 675 * Returns: 0 on success, not 0 on failure 676 */ 677 int dm_spi_xfer(struct udevice *dev, unsigned int bitlen, 678 const void *dout, void *din, unsigned long flags); 679 680 /** 681 * spi_get_mmap() - Get memory-mapped SPI 682 * 683 * @dev: SPI slave device to check 684 * @map_basep: Returns base memory address for mapped SPI 685 * @map_sizep: Returns size of mapped SPI 686 * @offsetp: Returns start offset of SPI flash where the map works 687 * correctly (offsets before this are not visible) 688 * @return 0 if OK, -ENOSYS if no operation, -EFAULT if memory mapping is not 689 * available 690 */ 691 int dm_spi_get_mmap(struct udevice *dev, ulong *map_basep, uint *map_sizep, 692 uint *offsetp); 693 694 /* Access the operations for a SPI device */ 695 #define spi_get_ops(dev) ((struct dm_spi_ops *)(dev)->driver->ops) 696 #define spi_emul_get_ops(dev) ((struct dm_spi_emul_ops *)(dev)->driver->ops) 697 #endif /* CONFIG_DM_SPI */ 698 699 #endif /* _SPI_H_ */ 700