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