1 /* SPDX-License-Identifier: GPL-2.0+ */ 2 /* 3 * Copyright (C) 2018 Exceet Electronics GmbH 4 * Copyright (C) 2018 Bootlin 5 * 6 * Author: 7 * Peter Pan <peterpandong@micron.com> 8 * Boris Brezillon <boris.brezillon@bootlin.com> 9 */ 10 11 #ifndef __LINUX_SPI_MEM_H 12 #define __LINUX_SPI_MEM_H 13 14 #include <linux/spi/spi.h> 15 16 #define SPI_MEM_OP_CMD(__opcode, __buswidth) \ 17 { \ 18 .buswidth = __buswidth, \ 19 .opcode = __opcode, \ 20 .nbytes = 1, \ 21 } 22 23 #define SPI_MEM_OP_ADDR(__nbytes, __val, __buswidth) \ 24 { \ 25 .nbytes = __nbytes, \ 26 .val = __val, \ 27 .buswidth = __buswidth, \ 28 } 29 30 #define SPI_MEM_OP_NO_ADDR { } 31 32 #define SPI_MEM_OP_DUMMY(__nbytes, __buswidth) \ 33 { \ 34 .nbytes = __nbytes, \ 35 .buswidth = __buswidth, \ 36 } 37 38 #define SPI_MEM_OP_NO_DUMMY { } 39 40 #define SPI_MEM_OP_DATA_IN(__nbytes, __buf, __buswidth) \ 41 { \ 42 .dir = SPI_MEM_DATA_IN, \ 43 .nbytes = __nbytes, \ 44 .buf.in = __buf, \ 45 .buswidth = __buswidth, \ 46 } 47 48 #define SPI_MEM_OP_DATA_OUT(__nbytes, __buf, __buswidth) \ 49 { \ 50 .dir = SPI_MEM_DATA_OUT, \ 51 .nbytes = __nbytes, \ 52 .buf.out = __buf, \ 53 .buswidth = __buswidth, \ 54 } 55 56 #define SPI_MEM_OP_NO_DATA { } 57 58 /** 59 * enum spi_mem_data_dir - describes the direction of a SPI memory data 60 * transfer from the controller perspective 61 * @SPI_MEM_NO_DATA: no data transferred 62 * @SPI_MEM_DATA_IN: data coming from the SPI memory 63 * @SPI_MEM_DATA_OUT: data sent to the SPI memory 64 */ 65 enum spi_mem_data_dir { 66 SPI_MEM_NO_DATA, 67 SPI_MEM_DATA_IN, 68 SPI_MEM_DATA_OUT, 69 }; 70 71 /** 72 * struct spi_mem_op - describes a SPI memory operation 73 * @cmd.nbytes: number of opcode bytes (only 1 or 2 are valid). The opcode is 74 * sent MSB-first. 75 * @cmd.buswidth: number of IO lines used to transmit the command 76 * @cmd.opcode: operation opcode 77 * @cmd.dtr: whether the command opcode should be sent in DTR mode or not 78 * @addr.nbytes: number of address bytes to send. Can be zero if the operation 79 * does not need to send an address 80 * @addr.buswidth: number of IO lines used to transmit the address cycles 81 * @addr.dtr: whether the address should be sent in DTR mode or not 82 * @addr.val: address value. This value is always sent MSB first on the bus. 83 * Note that only @addr.nbytes are taken into account in this 84 * address value, so users should make sure the value fits in the 85 * assigned number of bytes. 86 * @dummy.nbytes: number of dummy bytes to send after an opcode or address. Can 87 * be zero if the operation does not require dummy bytes 88 * @dummy.buswidth: number of IO lanes used to transmit the dummy bytes 89 * @dummy.dtr: whether the dummy bytes should be sent in DTR mode or not 90 * @data.buswidth: number of IO lanes used to send/receive the data 91 * @data.dtr: whether the data should be sent in DTR mode or not 92 * @data.ecc: whether error correction is required or not 93 * @data.dir: direction of the transfer 94 * @data.nbytes: number of data bytes to send/receive. Can be zero if the 95 * operation does not involve transferring data 96 * @data.buf.in: input buffer (must be DMA-able) 97 * @data.buf.out: output buffer (must be DMA-able) 98 */ 99 struct spi_mem_op { 100 struct { 101 u8 nbytes; 102 u8 buswidth; 103 u8 dtr : 1; 104 u16 opcode; 105 } cmd; 106 107 struct { 108 u8 nbytes; 109 u8 buswidth; 110 u8 dtr : 1; 111 u64 val; 112 } addr; 113 114 struct { 115 u8 nbytes; 116 u8 buswidth; 117 u8 dtr : 1; 118 } dummy; 119 120 struct { 121 u8 buswidth; 122 u8 dtr : 1; 123 u8 ecc : 1; 124 enum spi_mem_data_dir dir; 125 unsigned int nbytes; 126 union { 127 void *in; 128 const void *out; 129 } buf; 130 } data; 131 }; 132 133 #define SPI_MEM_OP(__cmd, __addr, __dummy, __data) \ 134 { \ 135 .cmd = __cmd, \ 136 .addr = __addr, \ 137 .dummy = __dummy, \ 138 .data = __data, \ 139 } 140 141 /** 142 * struct spi_mem_dirmap_info - Direct mapping information 143 * @op_tmpl: operation template that should be used by the direct mapping when 144 * the memory device is accessed 145 * @offset: absolute offset this direct mapping is pointing to 146 * @length: length in byte of this direct mapping 147 * 148 * These information are used by the controller specific implementation to know 149 * the portion of memory that is directly mapped and the spi_mem_op that should 150 * be used to access the device. 151 * A direct mapping is only valid for one direction (read or write) and this 152 * direction is directly encoded in the ->op_tmpl.data.dir field. 153 */ 154 struct spi_mem_dirmap_info { 155 struct spi_mem_op op_tmpl; 156 u64 offset; 157 u64 length; 158 }; 159 160 /** 161 * struct spi_mem_dirmap_desc - Direct mapping descriptor 162 * @mem: the SPI memory device this direct mapping is attached to 163 * @info: information passed at direct mapping creation time 164 * @nodirmap: set to 1 if the SPI controller does not implement 165 * ->mem_ops->dirmap_create() or when this function returned an 166 * error. If @nodirmap is true, all spi_mem_dirmap_{read,write}() 167 * calls will use spi_mem_exec_op() to access the memory. This is a 168 * degraded mode that allows spi_mem drivers to use the same code 169 * no matter whether the controller supports direct mapping or not 170 * @priv: field pointing to controller specific data 171 * 172 * Common part of a direct mapping descriptor. This object is created by 173 * spi_mem_dirmap_create() and controller implementation of ->create_dirmap() 174 * can create/attach direct mapping resources to the descriptor in the ->priv 175 * field. 176 */ 177 struct spi_mem_dirmap_desc { 178 struct spi_mem *mem; 179 struct spi_mem_dirmap_info info; 180 unsigned int nodirmap; 181 void *priv; 182 }; 183 184 /** 185 * struct spi_mem - describes a SPI memory device 186 * @spi: the underlying SPI device 187 * @drvpriv: spi_mem_driver private data 188 * @name: name of the SPI memory device 189 * 190 * Extra information that describe the SPI memory device and may be needed by 191 * the controller to properly handle this device should be placed here. 192 * 193 * One example would be the device size since some controller expose their SPI 194 * mem devices through a io-mapped region. 195 */ 196 struct spi_mem { 197 struct spi_device *spi; 198 void *drvpriv; 199 const char *name; 200 }; 201 202 /** 203 * struct spi_mem_set_drvdata() - attach driver private data to a SPI mem 204 * device 205 * @mem: memory device 206 * @data: data to attach to the memory device 207 */ 208 static inline void spi_mem_set_drvdata(struct spi_mem *mem, void *data) 209 { 210 mem->drvpriv = data; 211 } 212 213 /** 214 * struct spi_mem_get_drvdata() - get driver private data attached to a SPI mem 215 * device 216 * @mem: memory device 217 * 218 * Return: the data attached to the mem device. 219 */ 220 static inline void *spi_mem_get_drvdata(struct spi_mem *mem) 221 { 222 return mem->drvpriv; 223 } 224 225 /** 226 * struct spi_controller_mem_ops - SPI memory operations 227 * @adjust_op_size: shrink the data xfer of an operation to match controller's 228 * limitations (can be alignment or max RX/TX size 229 * limitations) 230 * @supports_op: check if an operation is supported by the controller 231 * @exec_op: execute a SPI memory operation 232 * @get_name: get a custom name for the SPI mem device from the controller. 233 * This might be needed if the controller driver has been ported 234 * to use the SPI mem layer and a custom name is used to keep 235 * mtdparts compatible. 236 * Note that if the implementation of this function allocates memory 237 * dynamically, then it should do so with devm_xxx(), as we don't 238 * have a ->free_name() function. 239 * @dirmap_create: create a direct mapping descriptor that can later be used to 240 * access the memory device. This method is optional 241 * @dirmap_destroy: destroy a memory descriptor previous created by 242 * ->dirmap_create() 243 * @dirmap_read: read data from the memory device using the direct mapping 244 * created by ->dirmap_create(). The function can return less 245 * data than requested (for example when the request is crossing 246 * the currently mapped area), and the caller of 247 * spi_mem_dirmap_read() is responsible for calling it again in 248 * this case. 249 * @dirmap_write: write data to the memory device using the direct mapping 250 * created by ->dirmap_create(). The function can return less 251 * data than requested (for example when the request is crossing 252 * the currently mapped area), and the caller of 253 * spi_mem_dirmap_write() is responsible for calling it again in 254 * this case. 255 * @poll_status: poll memory device status until (status & mask) == match or 256 * when the timeout has expired. It fills the data buffer with 257 * the last status value. 258 * 259 * This interface should be implemented by SPI controllers providing an 260 * high-level interface to execute SPI memory operation, which is usually the 261 * case for QSPI controllers. 262 * 263 * Note on ->dirmap_{read,write}(): drivers should avoid accessing the direct 264 * mapping from the CPU because doing that can stall the CPU waiting for the 265 * SPI mem transaction to finish, and this will make real-time maintainers 266 * unhappy and might make your system less reactive. Instead, drivers should 267 * use DMA to access this direct mapping. 268 */ 269 struct spi_controller_mem_ops { 270 int (*adjust_op_size)(struct spi_mem *mem, struct spi_mem_op *op); 271 bool (*supports_op)(struct spi_mem *mem, 272 const struct spi_mem_op *op); 273 int (*exec_op)(struct spi_mem *mem, 274 const struct spi_mem_op *op); 275 const char *(*get_name)(struct spi_mem *mem); 276 int (*dirmap_create)(struct spi_mem_dirmap_desc *desc); 277 void (*dirmap_destroy)(struct spi_mem_dirmap_desc *desc); 278 ssize_t (*dirmap_read)(struct spi_mem_dirmap_desc *desc, 279 u64 offs, size_t len, void *buf); 280 ssize_t (*dirmap_write)(struct spi_mem_dirmap_desc *desc, 281 u64 offs, size_t len, const void *buf); 282 int (*poll_status)(struct spi_mem *mem, 283 const struct spi_mem_op *op, 284 u16 mask, u16 match, 285 unsigned long initial_delay_us, 286 unsigned long polling_rate_us, 287 unsigned long timeout_ms); 288 }; 289 290 /** 291 * struct spi_controller_mem_caps - SPI memory controller capabilities 292 * @dtr: Supports DTR operations 293 * @ecc: Supports operations with error correction 294 */ 295 struct spi_controller_mem_caps { 296 bool dtr; 297 bool ecc; 298 }; 299 300 #define spi_mem_controller_is_capable(ctlr, cap) \ 301 ((ctlr)->mem_caps && (ctlr)->mem_caps->cap) 302 303 /** 304 * struct spi_mem_driver - SPI memory driver 305 * @spidrv: inherit from a SPI driver 306 * @probe: probe a SPI memory. Usually where detection/initialization takes 307 * place 308 * @remove: remove a SPI memory 309 * @shutdown: take appropriate action when the system is shutdown 310 * 311 * This is just a thin wrapper around a spi_driver. The core takes care of 312 * allocating the spi_mem object and forwarding the probe/remove/shutdown 313 * request to the spi_mem_driver. The reason we use this wrapper is because 314 * we might have to stuff more information into the spi_mem struct to let 315 * SPI controllers know more about the SPI memory they interact with, and 316 * having this intermediate layer allows us to do that without adding more 317 * useless fields to the spi_device object. 318 */ 319 struct spi_mem_driver { 320 struct spi_driver spidrv; 321 int (*probe)(struct spi_mem *mem); 322 int (*remove)(struct spi_mem *mem); 323 void (*shutdown)(struct spi_mem *mem); 324 }; 325 326 #if IS_ENABLED(CONFIG_SPI_MEM) 327 int spi_controller_dma_map_mem_op_data(struct spi_controller *ctlr, 328 const struct spi_mem_op *op, 329 struct sg_table *sg); 330 331 void spi_controller_dma_unmap_mem_op_data(struct spi_controller *ctlr, 332 const struct spi_mem_op *op, 333 struct sg_table *sg); 334 335 bool spi_mem_default_supports_op(struct spi_mem *mem, 336 const struct spi_mem_op *op); 337 #else 338 static inline int 339 spi_controller_dma_map_mem_op_data(struct spi_controller *ctlr, 340 const struct spi_mem_op *op, 341 struct sg_table *sg) 342 { 343 return -ENOTSUPP; 344 } 345 346 static inline void 347 spi_controller_dma_unmap_mem_op_data(struct spi_controller *ctlr, 348 const struct spi_mem_op *op, 349 struct sg_table *sg) 350 { 351 } 352 353 static inline 354 bool spi_mem_default_supports_op(struct spi_mem *mem, 355 const struct spi_mem_op *op) 356 { 357 return false; 358 } 359 #endif /* CONFIG_SPI_MEM */ 360 361 int spi_mem_adjust_op_size(struct spi_mem *mem, struct spi_mem_op *op); 362 363 bool spi_mem_supports_op(struct spi_mem *mem, 364 const struct spi_mem_op *op); 365 366 int spi_mem_exec_op(struct spi_mem *mem, 367 const struct spi_mem_op *op); 368 369 const char *spi_mem_get_name(struct spi_mem *mem); 370 371 struct spi_mem_dirmap_desc * 372 spi_mem_dirmap_create(struct spi_mem *mem, 373 const struct spi_mem_dirmap_info *info); 374 void spi_mem_dirmap_destroy(struct spi_mem_dirmap_desc *desc); 375 ssize_t spi_mem_dirmap_read(struct spi_mem_dirmap_desc *desc, 376 u64 offs, size_t len, void *buf); 377 ssize_t spi_mem_dirmap_write(struct spi_mem_dirmap_desc *desc, 378 u64 offs, size_t len, const void *buf); 379 struct spi_mem_dirmap_desc * 380 devm_spi_mem_dirmap_create(struct device *dev, struct spi_mem *mem, 381 const struct spi_mem_dirmap_info *info); 382 void devm_spi_mem_dirmap_destroy(struct device *dev, 383 struct spi_mem_dirmap_desc *desc); 384 385 int spi_mem_poll_status(struct spi_mem *mem, 386 const struct spi_mem_op *op, 387 u16 mask, u16 match, 388 unsigned long initial_delay_us, 389 unsigned long polling_delay_us, 390 u16 timeout_ms); 391 392 int spi_mem_driver_register_with_owner(struct spi_mem_driver *drv, 393 struct module *owner); 394 395 void spi_mem_driver_unregister(struct spi_mem_driver *drv); 396 397 #define spi_mem_driver_register(__drv) \ 398 spi_mem_driver_register_with_owner(__drv, THIS_MODULE) 399 400 #define module_spi_mem_driver(__drv) \ 401 module_driver(__drv, spi_mem_driver_register, \ 402 spi_mem_driver_unregister) 403 404 #endif /* __LINUX_SPI_MEM_H */ 405