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 /* SPI mode flags */ 14 #define SPI_CPHA BIT(0) /* clock phase */ 15 #define SPI_CPOL BIT(1) /* clock polarity */ 16 #define SPI_MODE_0 (0|0) /* (original MicroWire) */ 17 #define SPI_MODE_1 (0|SPI_CPHA) 18 #define SPI_MODE_2 (SPI_CPOL|0) 19 #define SPI_MODE_3 (SPI_CPOL|SPI_CPHA) 20 #define SPI_CS_HIGH BIT(2) /* CS active high */ 21 #define SPI_LSB_FIRST BIT(3) /* per-word bits-on-wire */ 22 #define SPI_3WIRE BIT(4) /* SI/SO signals shared */ 23 #define SPI_LOOP BIT(5) /* loopback mode */ 24 #define SPI_SLAVE BIT(6) /* slave mode */ 25 #define SPI_PREAMBLE BIT(7) /* Skip preamble bytes */ 26 #define SPI_TX_BYTE BIT(8) /* transmit with 1 wire byte */ 27 #define SPI_TX_DUAL BIT(9) /* transmit with 2 wires */ 28 #define SPI_TX_QUAD BIT(10) /* transmit with 4 wires */ 29 #define SPI_RX_SLOW BIT(11) /* receive with 1 wire slow */ 30 #define SPI_RX_DUAL BIT(12) /* receive with 2 wires */ 31 #define SPI_RX_QUAD BIT(13) /* receive with 4 wires */ 32 33 /* Header byte that marks the start of the message */ 34 #define SPI_PREAMBLE_END_BYTE 0xec 35 36 #define SPI_DEFAULT_WORDLEN 8 37 38 #ifdef CONFIG_DM_SPI 39 /* TODO(sjg@chromium.org): Remove this and use max_hz from struct spi_slave */ 40 struct dm_spi_bus { 41 uint max_hz; 42 }; 43 44 /** 45 * struct dm_spi_platdata - platform data for all SPI slaves 46 * 47 * This describes a SPI slave, a child device of the SPI bus. To obtain this 48 * struct from a spi_slave, use dev_get_parent_platdata(dev) or 49 * dev_get_parent_platdata(slave->dev). 50 * 51 * This data is immuatable. Each time the device is probed, @max_hz and @mode 52 * will be copied to struct spi_slave. 53 * 54 * @cs: Chip select number (0..n-1) 55 * @max_hz: Maximum bus speed that this slave can tolerate 56 * @mode: SPI mode to use for this device (see SPI mode flags) 57 */ 58 struct dm_spi_slave_platdata { 59 unsigned int cs; 60 uint max_hz; 61 uint mode; 62 }; 63 64 #endif /* CONFIG_DM_SPI */ 65 66 /** 67 * struct spi_slave - Representation of a SPI slave 68 * 69 * For driver model this is the per-child data used by the SPI bus. It can 70 * be accessed using dev_get_parent_priv() on the slave device. The SPI uclass 71 * sets uip per_child_auto_alloc_size to sizeof(struct spi_slave), and the 72 * driver should not override it. Two platform data fields (max_hz and mode) 73 * are copied into this structure to provide an initial value. This allows 74 * them to be changed, since we should never change platform data in drivers. 75 * 76 * If not using driver model, drivers are expected to extend this with 77 * controller-specific data. 78 * 79 * @dev: SPI slave device 80 * @max_hz: Maximum speed for this slave 81 * @speed: Current bus speed. This is 0 until the bus is first 82 * claimed. 83 * @bus: ID of the bus that the slave is attached to. For 84 * driver model this is the sequence number of the SPI 85 * bus (bus->seq) so does not need to be stored 86 * @cs: ID of the chip select connected to the slave. 87 * @mode: SPI mode to use for this slave (see SPI mode flags) 88 * @wordlen: Size of SPI word in number of bits 89 * @max_read_size: If non-zero, the maximum number of bytes which can 90 * be read at once. 91 * @max_write_size: If non-zero, the maximum number of bytes which can 92 * be written at once. 93 * @memory_map: Address of read-only SPI flash access. 94 * @flags: Indication of SPI flags. 95 */ 96 struct spi_slave { 97 #ifdef CONFIG_DM_SPI 98 struct udevice *dev; /* struct spi_slave is dev->parentdata */ 99 uint max_hz; 100 uint speed; 101 #else 102 unsigned int bus; 103 unsigned int cs; 104 #endif 105 uint mode; 106 unsigned int wordlen; 107 unsigned int max_read_size; 108 unsigned int max_write_size; 109 void *memory_map; 110 111 u8 flags; 112 #define SPI_XFER_BEGIN BIT(0) /* Assert CS before transfer */ 113 #define SPI_XFER_END BIT(1) /* Deassert CS after transfer */ 114 #define SPI_XFER_ONCE (SPI_XFER_BEGIN | SPI_XFER_END) 115 #define SPI_XFER_MMAP BIT(2) /* Memory Mapped start */ 116 #define SPI_XFER_MMAP_END BIT(3) /* Memory Mapped End */ 117 }; 118 119 /** 120 * Initialization, must be called once on start up. 121 * 122 * TODO: I don't think we really need this. 123 */ 124 void spi_init(void); 125 126 /** 127 * spi_do_alloc_slave - Allocate a new SPI slave (internal) 128 * 129 * Allocate and zero all fields in the spi slave, and set the bus/chip 130 * select. Use the helper macro spi_alloc_slave() to call this. 131 * 132 * @offset: Offset of struct spi_slave within slave structure. 133 * @size: Size of slave structure. 134 * @bus: Bus ID of the slave chip. 135 * @cs: Chip select ID of the slave chip on the specified bus. 136 */ 137 void *spi_do_alloc_slave(int offset, int size, unsigned int bus, 138 unsigned int cs); 139 140 /** 141 * spi_alloc_slave - Allocate a new SPI slave 142 * 143 * Allocate and zero all fields in the spi slave, and set the bus/chip 144 * select. 145 * 146 * @_struct: Name of structure to allocate (e.g. struct tegra_spi). 147 * This structure must contain a member 'struct spi_slave *slave'. 148 * @bus: Bus ID of the slave chip. 149 * @cs: Chip select ID of the slave chip on the specified bus. 150 */ 151 #define spi_alloc_slave(_struct, bus, cs) \ 152 spi_do_alloc_slave(offsetof(_struct, slave), \ 153 sizeof(_struct), bus, cs) 154 155 /** 156 * spi_alloc_slave_base - Allocate a new SPI slave with no private data 157 * 158 * Allocate and zero all fields in the spi slave, and set the bus/chip 159 * select. 160 * 161 * @bus: Bus ID of the slave chip. 162 * @cs: Chip select ID of the slave chip on the specified bus. 163 */ 164 #define spi_alloc_slave_base(bus, cs) \ 165 spi_do_alloc_slave(0, sizeof(struct spi_slave), bus, cs) 166 167 /** 168 * Set up communications parameters for a SPI slave. 169 * 170 * This must be called once for each slave. Note that this function 171 * usually doesn't touch any actual hardware, it only initializes the 172 * contents of spi_slave so that the hardware can be easily 173 * initialized later. 174 * 175 * @bus: Bus ID of the slave chip. 176 * @cs: Chip select ID of the slave chip on the specified bus. 177 * @max_hz: Maximum SCK rate in Hz. 178 * @mode: Clock polarity, clock phase and other parameters. 179 * 180 * Returns: A spi_slave reference that can be used in subsequent SPI 181 * calls, or NULL if one or more of the parameters are not supported. 182 */ 183 struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs, 184 unsigned int max_hz, unsigned int mode); 185 186 /** 187 * Free any memory associated with a SPI slave. 188 * 189 * @slave: The SPI slave 190 */ 191 void spi_free_slave(struct spi_slave *slave); 192 193 /** 194 * Claim the bus and prepare it for communication with a given slave. 195 * 196 * This must be called before doing any transfers with a SPI slave. It 197 * will enable and initialize any SPI hardware as necessary, and make 198 * sure that the SCK line is in the correct idle state. It is not 199 * allowed to claim the same bus for several slaves without releasing 200 * the bus in between. 201 * 202 * @slave: The SPI slave 203 * 204 * Returns: 0 if the bus was claimed successfully, or a negative value 205 * if it wasn't. 206 */ 207 int spi_claim_bus(struct spi_slave *slave); 208 209 /** 210 * Release the SPI bus 211 * 212 * This must be called once for every call to spi_claim_bus() after 213 * all transfers have finished. It may disable any SPI hardware as 214 * appropriate. 215 * 216 * @slave: The SPI slave 217 */ 218 void spi_release_bus(struct spi_slave *slave); 219 220 /** 221 * Set the word length for SPI transactions 222 * 223 * Set the word length (number of bits per word) for SPI transactions. 224 * 225 * @slave: The SPI slave 226 * @wordlen: The number of bits in a word 227 * 228 * Returns: 0 on success, -1 on failure. 229 */ 230 int spi_set_wordlen(struct spi_slave *slave, unsigned int wordlen); 231 232 /** 233 * SPI transfer 234 * 235 * This writes "bitlen" bits out the SPI MOSI port and simultaneously clocks 236 * "bitlen" bits in the SPI MISO port. That's just the way SPI works. 237 * 238 * The source of the outgoing bits is the "dout" parameter and the 239 * destination of the input bits is the "din" parameter. Note that "dout" 240 * and "din" can point to the same memory location, in which case the 241 * input data overwrites the output data (since both are buffered by 242 * temporary variables, this is OK). 243 * 244 * spi_xfer() interface: 245 * @slave: The SPI slave which will be sending/receiving the data. 246 * @bitlen: How many bits to write and read. 247 * @dout: Pointer to a string of bits to send out. The bits are 248 * held in a byte array and are sent MSB first. 249 * @din: Pointer to a string of bits that will be filled in. 250 * @flags: A bitwise combination of SPI_XFER_* flags. 251 * 252 * Returns: 0 on success, not 0 on failure 253 */ 254 int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout, 255 void *din, unsigned long flags); 256 257 /* Copy memory mapped data */ 258 void spi_flash_copy_mmap(void *data, void *offset, size_t len); 259 260 /** 261 * Determine if a SPI chipselect is valid. 262 * This function is provided by the board if the low-level SPI driver 263 * needs it to determine if a given chipselect is actually valid. 264 * 265 * Returns: 1 if bus:cs identifies a valid chip on this board, 0 266 * otherwise. 267 */ 268 int spi_cs_is_valid(unsigned int bus, unsigned int cs); 269 270 #ifndef CONFIG_DM_SPI 271 /** 272 * Activate a SPI chipselect. 273 * This function is provided by the board code when using a driver 274 * that can't control its chipselects automatically (e.g. 275 * common/soft_spi.c). When called, it should activate the chip select 276 * to the device identified by "slave". 277 */ 278 void spi_cs_activate(struct spi_slave *slave); 279 280 /** 281 * Deactivate a SPI chipselect. 282 * This function is provided by the board code when using a driver 283 * that can't control its chipselects automatically (e.g. 284 * common/soft_spi.c). When called, it should deactivate the chip 285 * select to the device identified by "slave". 286 */ 287 void spi_cs_deactivate(struct spi_slave *slave); 288 289 /** 290 * Set transfer speed. 291 * This sets a new speed to be applied for next spi_xfer(). 292 * @slave: The SPI slave 293 * @hz: The transfer speed 294 */ 295 void spi_set_speed(struct spi_slave *slave, uint hz); 296 #endif 297 298 /** 299 * Write 8 bits, then read 8 bits. 300 * @slave: The SPI slave we're communicating with 301 * @byte: Byte to be written 302 * 303 * Returns: The value that was read, or a negative value on error. 304 * 305 * TODO: This function probably shouldn't be inlined. 306 */ 307 static inline int spi_w8r8(struct spi_slave *slave, unsigned char byte) 308 { 309 unsigned char dout[2]; 310 unsigned char din[2]; 311 int ret; 312 313 dout[0] = byte; 314 dout[1] = 0; 315 316 ret = spi_xfer(slave, 16, dout, din, SPI_XFER_BEGIN | SPI_XFER_END); 317 return ret < 0 ? ret : din[1]; 318 } 319 320 #ifdef CONFIG_DM_SPI 321 322 /** 323 * struct spi_cs_info - Information about a bus chip select 324 * 325 * @dev: Connected device, or NULL if none 326 */ 327 struct spi_cs_info { 328 struct udevice *dev; 329 }; 330 331 /** 332 * struct struct dm_spi_ops - Driver model SPI operations 333 * 334 * The uclass interface is implemented by all SPI devices which use 335 * driver model. 336 */ 337 struct dm_spi_ops { 338 /** 339 * Claim the bus and prepare it for communication. 340 * 341 * The device provided is the slave device. It's parent controller 342 * will be used to provide the communication. 343 * 344 * This must be called before doing any transfers with a SPI slave. It 345 * will enable and initialize any SPI hardware as necessary, and make 346 * sure that the SCK line is in the correct idle state. It is not 347 * allowed to claim the same bus for several slaves without releasing 348 * the bus in between. 349 * 350 * @dev: The SPI slave 351 * 352 * Returns: 0 if the bus was claimed successfully, or a negative value 353 * if it wasn't. 354 */ 355 int (*claim_bus)(struct udevice *dev); 356 357 /** 358 * Release the SPI bus 359 * 360 * This must be called once for every call to spi_claim_bus() after 361 * all transfers have finished. It may disable any SPI hardware as 362 * appropriate. 363 * 364 * @dev: The SPI slave 365 */ 366 int (*release_bus)(struct udevice *dev); 367 368 /** 369 * Set the word length for SPI transactions 370 * 371 * Set the word length (number of bits per word) for SPI transactions. 372 * 373 * @bus: The SPI slave 374 * @wordlen: The number of bits in a word 375 * 376 * Returns: 0 on success, -ve on failure. 377 */ 378 int (*set_wordlen)(struct udevice *dev, unsigned int wordlen); 379 380 /** 381 * SPI transfer 382 * 383 * This writes "bitlen" bits out the SPI MOSI port and simultaneously 384 * clocks "bitlen" bits in the SPI MISO port. That's just the way SPI 385 * works. 386 * 387 * The source of the outgoing bits is the "dout" parameter and the 388 * destination of the input bits is the "din" parameter. Note that 389 * "dout" and "din" can point to the same memory location, in which 390 * case the input data overwrites the output data (since both are 391 * buffered by temporary variables, this is OK). 392 * 393 * spi_xfer() interface: 394 * @dev: The slave device to communicate with 395 * @bitlen: How many bits to write and read. 396 * @dout: Pointer to a string of bits to send out. The bits are 397 * held in a byte array and are sent MSB first. 398 * @din: Pointer to a string of bits that will be filled in. 399 * @flags: A bitwise combination of SPI_XFER_* flags. 400 * 401 * Returns: 0 on success, not -1 on failure 402 */ 403 int (*xfer)(struct udevice *dev, unsigned int bitlen, const void *dout, 404 void *din, unsigned long flags); 405 406 /** 407 * Set transfer speed. 408 * This sets a new speed to be applied for next spi_xfer(). 409 * @bus: The SPI bus 410 * @hz: The transfer speed 411 * @return 0 if OK, -ve on error 412 */ 413 int (*set_speed)(struct udevice *bus, uint hz); 414 415 /** 416 * Set the SPI mode/flags 417 * 418 * It is unclear if we want to set speed and mode together instead 419 * of separately. 420 * 421 * @bus: The SPI bus 422 * @mode: Requested SPI mode (SPI_... flags) 423 * @return 0 if OK, -ve on error 424 */ 425 int (*set_mode)(struct udevice *bus, uint mode); 426 427 /** 428 * Get information on a chip select 429 * 430 * This is only called when the SPI uclass does not know about a 431 * chip select, i.e. it has no attached device. It gives the driver 432 * a chance to allow activity on that chip select even so. 433 * 434 * @bus: The SPI bus 435 * @cs: The chip select (0..n-1) 436 * @info: Returns information about the chip select, if valid. 437 * On entry info->dev is NULL 438 * @return 0 if OK (and @info is set up), -ENODEV if the chip select 439 * is invalid, other -ve value on error 440 */ 441 int (*cs_info)(struct udevice *bus, uint cs, struct spi_cs_info *info); 442 }; 443 444 struct dm_spi_emul_ops { 445 /** 446 * SPI transfer 447 * 448 * This writes "bitlen" bits out the SPI MOSI port and simultaneously 449 * clocks "bitlen" bits in the SPI MISO port. That's just the way SPI 450 * works. Here the device is a slave. 451 * 452 * The source of the outgoing bits is the "dout" parameter and the 453 * destination of the input bits is the "din" parameter. Note that 454 * "dout" and "din" can point to the same memory location, in which 455 * case the input data overwrites the output data (since both are 456 * buffered by temporary variables, this is OK). 457 * 458 * spi_xfer() interface: 459 * @slave: The SPI slave which will be sending/receiving the data. 460 * @bitlen: How many bits to write and read. 461 * @dout: Pointer to a string of bits sent to the device. The 462 * bits are held in a byte array and are sent MSB first. 463 * @din: Pointer to a string of bits that will be sent back to 464 * the master. 465 * @flags: A bitwise combination of SPI_XFER_* flags. 466 * 467 * Returns: 0 on success, not -1 on failure 468 */ 469 int (*xfer)(struct udevice *slave, unsigned int bitlen, 470 const void *dout, void *din, unsigned long flags); 471 }; 472 473 /** 474 * spi_find_bus_and_cs() - Find bus and slave devices by number 475 * 476 * Given a bus number and chip select, this finds the corresponding bus 477 * device and slave device. Neither device is activated by this function, 478 * although they may have been activated previously. 479 * 480 * @busnum: SPI bus number 481 * @cs: Chip select to look for 482 * @busp: Returns bus device 483 * @devp: Return slave device 484 * @return 0 if found, -ENODEV on error 485 */ 486 int spi_find_bus_and_cs(int busnum, int cs, struct udevice **busp, 487 struct udevice **devp); 488 489 /** 490 * spi_get_bus_and_cs() - Find and activate bus and slave devices by number 491 * 492 * Given a bus number and chip select, this finds the corresponding bus 493 * device and slave device. 494 * 495 * If no such slave exists, and drv_name is not NULL, then a new slave device 496 * is automatically bound on this chip select. 497 * 498 * Ths new slave device is probed ready for use with the given speed and mode. 499 * 500 * @busnum: SPI bus number 501 * @cs: Chip select to look for 502 * @speed: SPI speed to use for this slave 503 * @mode: SPI mode to use for this slave 504 * @drv_name: Name of driver to attach to this chip select 505 * @dev_name: Name of the new device thus created 506 * @busp: Returns bus device 507 * @devp: Return slave device 508 * @return 0 if found, -ve on error 509 */ 510 int spi_get_bus_and_cs(int busnum, int cs, int speed, int mode, 511 const char *drv_name, const char *dev_name, 512 struct udevice **busp, struct spi_slave **devp); 513 514 /** 515 * spi_chip_select() - Get the chip select for a slave 516 * 517 * @return the chip select this slave is attached to 518 */ 519 int spi_chip_select(struct udevice *slave); 520 521 /** 522 * spi_find_chip_select() - Find the slave attached to chip select 523 * 524 * @bus: SPI bus to search 525 * @cs: Chip select to look for 526 * @devp: Returns the slave device if found 527 * @return 0 if found, -ENODEV on error 528 */ 529 int spi_find_chip_select(struct udevice *bus, int cs, struct udevice **devp); 530 531 /** 532 * spi_slave_ofdata_to_platdata() - decode standard SPI platform data 533 * 534 * This decodes the speed and mode for a slave from a device tree node 535 * 536 * @blob: Device tree blob 537 * @node: Node offset to read from 538 * @plat: Place to put the decoded information 539 */ 540 int spi_slave_ofdata_to_platdata(struct udevice *dev, 541 struct dm_spi_slave_platdata *plat); 542 543 /** 544 * spi_cs_info() - Check information on a chip select 545 * 546 * This checks a particular chip select on a bus to see if it has a device 547 * attached, or is even valid. 548 * 549 * @bus: The SPI bus 550 * @cs: The chip select (0..n-1) 551 * @info: Returns information about the chip select, if valid 552 * @return 0 if OK (and @info is set up), -ENODEV if the chip select 553 * is invalid, other -ve value on error 554 */ 555 int spi_cs_info(struct udevice *bus, uint cs, struct spi_cs_info *info); 556 557 struct sandbox_state; 558 559 /** 560 * sandbox_spi_get_emul() - get an emulator for a SPI slave 561 * 562 * This provides a way to attach an emulated SPI device to a particular SPI 563 * slave, so that xfer() operations on the slave will be handled by the 564 * emulator. If a emulator already exists on that chip select it is returned. 565 * Otherwise one is created. 566 * 567 * @state: Sandbox state 568 * @bus: SPI bus requesting the emulator 569 * @slave: SPI slave device requesting the emulator 570 * @emuip: Returns pointer to emulator 571 * @return 0 if OK, -ve on error 572 */ 573 int sandbox_spi_get_emul(struct sandbox_state *state, 574 struct udevice *bus, struct udevice *slave, 575 struct udevice **emulp); 576 577 /** 578 * Claim the bus and prepare it for communication with a given slave. 579 * 580 * This must be called before doing any transfers with a SPI slave. It 581 * will enable and initialize any SPI hardware as necessary, and make 582 * sure that the SCK line is in the correct idle state. It is not 583 * allowed to claim the same bus for several slaves without releasing 584 * the bus in between. 585 * 586 * @dev: The SPI slave device 587 * 588 * Returns: 0 if the bus was claimed successfully, or a negative value 589 * if it wasn't. 590 */ 591 int dm_spi_claim_bus(struct udevice *dev); 592 593 /** 594 * Release the SPI bus 595 * 596 * This must be called once for every call to dm_spi_claim_bus() after 597 * all transfers have finished. It may disable any SPI hardware as 598 * appropriate. 599 * 600 * @slave: The SPI slave device 601 */ 602 void dm_spi_release_bus(struct udevice *dev); 603 604 /** 605 * SPI transfer 606 * 607 * This writes "bitlen" bits out the SPI MOSI port and simultaneously clocks 608 * "bitlen" bits in the SPI MISO port. That's just the way SPI works. 609 * 610 * The source of the outgoing bits is the "dout" parameter and the 611 * destination of the input bits is the "din" parameter. Note that "dout" 612 * and "din" can point to the same memory location, in which case the 613 * input data overwrites the output data (since both are buffered by 614 * temporary variables, this is OK). 615 * 616 * dm_spi_xfer() interface: 617 * @dev: The SPI slave device which will be sending/receiving the data. 618 * @bitlen: How many bits to write and read. 619 * @dout: Pointer to a string of bits to send out. The bits are 620 * held in a byte array and are sent MSB first. 621 * @din: Pointer to a string of bits that will be filled in. 622 * @flags: A bitwise combination of SPI_XFER_* flags. 623 * 624 * Returns: 0 on success, not 0 on failure 625 */ 626 int dm_spi_xfer(struct udevice *dev, unsigned int bitlen, 627 const void *dout, void *din, unsigned long flags); 628 629 /* Access the operations for a SPI device */ 630 #define spi_get_ops(dev) ((struct dm_spi_ops *)(dev)->driver->ops) 631 #define spi_emul_get_ops(dev) ((struct dm_spi_emul_ops *)(dev)->driver->ops) 632 #endif /* CONFIG_DM_SPI */ 633 634 #endif /* _SPI_H_ */ 635