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