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 */
65enum 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 */
99struct spi_mem_op {
100 struct {
101 u8 nbytes;
102 u8 buswidth;
103 u8 dtr : 1;
104 u8 __pad : 7;
105 u16 opcode;
106 } cmd;
107
108 struct {
109 u8 nbytes;
110 u8 buswidth;
111 u8 dtr : 1;
112 u8 __pad : 7;
113 u64 val;
114 } addr;
115
116 struct {
117 u8 nbytes;
118 u8 buswidth;
119 u8 dtr : 1;
120 u8 __pad : 7;
121 } dummy;
122
123 struct {
124 u8 buswidth;
125 u8 dtr : 1;
126 u8 ecc : 1;
127 u8 __pad : 6;
128 enum spi_mem_data_dir dir;
129 unsigned int nbytes;
130 union {
131 void *in;
132 const void *out;
133 } buf;
134 } data;
135};
136
137#define SPI_MEM_OP(__cmd, __addr, __dummy, __data) \
138 { \
139 .cmd = __cmd, \
140 .addr = __addr, \
141 .dummy = __dummy, \
142 .data = __data, \
143 }
144
145/**
146 * struct spi_mem_dirmap_info - Direct mapping information
147 * @op_tmpl: operation template that should be used by the direct mapping when
148 * the memory device is accessed
149 * @offset: absolute offset this direct mapping is pointing to
150 * @length: length in byte of this direct mapping
151 *
152 * These information are used by the controller specific implementation to know
153 * the portion of memory that is directly mapped and the spi_mem_op that should
154 * be used to access the device.
155 * A direct mapping is only valid for one direction (read or write) and this
156 * direction is directly encoded in the ->op_tmpl.data.dir field.
157 */
158struct spi_mem_dirmap_info {
159 struct spi_mem_op op_tmpl;
160 u64 offset;
161 u64 length;
162};
163
164/**
165 * struct spi_mem_dirmap_desc - Direct mapping descriptor
166 * @mem: the SPI memory device this direct mapping is attached to
167 * @info: information passed at direct mapping creation time
168 * @nodirmap: set to 1 if the SPI controller does not implement
169 * ->mem_ops->dirmap_create() or when this function returned an
170 * error. If @nodirmap is true, all spi_mem_dirmap_{read,write}()
171 * calls will use spi_mem_exec_op() to access the memory. This is a
172 * degraded mode that allows spi_mem drivers to use the same code
173 * no matter whether the controller supports direct mapping or not
174 * @priv: field pointing to controller specific data
175 *
176 * Common part of a direct mapping descriptor. This object is created by
177 * spi_mem_dirmap_create() and controller implementation of ->create_dirmap()
178 * can create/attach direct mapping resources to the descriptor in the ->priv
179 * field.
180 */
181struct spi_mem_dirmap_desc {
182 struct spi_mem *mem;
183 struct spi_mem_dirmap_info info;
184 unsigned int nodirmap;
185 void *priv;
186};
187
188/**
189 * struct spi_mem - describes a SPI memory device
190 * @spi: the underlying SPI device
191 * @drvpriv: spi_mem_driver private data
192 * @name: name of the SPI memory device
193 *
194 * Extra information that describe the SPI memory device and may be needed by
195 * the controller to properly handle this device should be placed here.
196 *
197 * One example would be the device size since some controller expose their SPI
198 * mem devices through a io-mapped region.
199 */
200struct spi_mem {
201 struct spi_device *spi;
202 void *drvpriv;
203 const char *name;
204};
205
206/**
207 * struct spi_mem_set_drvdata() - attach driver private data to a SPI mem
208 * device
209 * @mem: memory device
210 * @data: data to attach to the memory device
211 */
212static inline void spi_mem_set_drvdata(struct spi_mem *mem, void *data)
213{
214 mem->drvpriv = data;
215}
216
217/**
218 * struct spi_mem_get_drvdata() - get driver private data attached to a SPI mem
219 * device
220 * @mem: memory device
221 *
222 * Return: the data attached to the mem device.
223 */
224static inline void *spi_mem_get_drvdata(struct spi_mem *mem)
225{
226 return mem->drvpriv;
227}
228
229/**
230 * struct spi_controller_mem_ops - SPI memory operations
231 * @adjust_op_size: shrink the data xfer of an operation to match controller's
232 * limitations (can be alignment or max RX/TX size
233 * limitations)
234 * @supports_op: check if an operation is supported by the controller
235 * @exec_op: execute a SPI memory operation
236 * not all driver provides supports_op(), so it can return -EOPNOTSUPP
237 * if the op is not supported by the driver/controller
238 * @get_name: get a custom name for the SPI mem device from the controller.
239 * This might be needed if the controller driver has been ported
240 * to use the SPI mem layer and a custom name is used to keep
241 * mtdparts compatible.
242 * Note that if the implementation of this function allocates memory
243 * dynamically, then it should do so with devm_xxx(), as we don't
244 * have a ->free_name() function.
245 * @dirmap_create: create a direct mapping descriptor that can later be used to
246 * access the memory device. This method is optional
247 * @dirmap_destroy: destroy a memory descriptor previous created by
248 * ->dirmap_create()
249 * @dirmap_read: read data from 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_read() is responsible for calling it again in
254 * this case.
255 * @dirmap_write: write data to the memory device using the direct mapping
256 * created by ->dirmap_create(). The function can return less
257 * data than requested (for example when the request is crossing
258 * the currently mapped area), and the caller of
259 * spi_mem_dirmap_write() is responsible for calling it again in
260 * this case.
261 * @poll_status: poll memory device status until (status & mask) == match or
262 * when the timeout has expired. It fills the data buffer with
263 * the last status value.
264 *
265 * This interface should be implemented by SPI controllers providing an
266 * high-level interface to execute SPI memory operation, which is usually the
267 * case for QSPI controllers.
268 *
269 * Note on ->dirmap_{read,write}(): drivers should avoid accessing the direct
270 * mapping from the CPU because doing that can stall the CPU waiting for the
271 * SPI mem transaction to finish, and this will make real-time maintainers
272 * unhappy and might make your system less reactive. Instead, drivers should
273 * use DMA to access this direct mapping.
274 */
275struct spi_controller_mem_ops {
276 int (*adjust_op_size)(struct spi_mem *mem, struct spi_mem_op *op);
277 bool (*supports_op)(struct spi_mem *mem,
278 const struct spi_mem_op *op);
279 int (*exec_op)(struct spi_mem *mem,
280 const struct spi_mem_op *op);
281 const char *(*get_name)(struct spi_mem *mem);
282 int (*dirmap_create)(struct spi_mem_dirmap_desc *desc);
283 void (*dirmap_destroy)(struct spi_mem_dirmap_desc *desc);
284 ssize_t (*dirmap_read)(struct spi_mem_dirmap_desc *desc,
285 u64 offs, size_t len, void *buf);
286 ssize_t (*dirmap_write)(struct spi_mem_dirmap_desc *desc,
287 u64 offs, size_t len, const void *buf);
288 int (*poll_status)(struct spi_mem *mem,
289 const struct spi_mem_op *op,
290 u16 mask, u16 match,
291 unsigned long initial_delay_us,
292 unsigned long polling_rate_us,
293 unsigned long timeout_ms);
294};
295
296/**
297 * struct spi_controller_mem_caps - SPI memory controller capabilities
298 * @dtr: Supports DTR operations
299 * @ecc: Supports operations with error correction
300 */
301struct spi_controller_mem_caps {
302 bool dtr;
303 bool ecc;
304};
305
306#define spi_mem_controller_is_capable(ctlr, cap) \
307 ((ctlr)->mem_caps && (ctlr)->mem_caps->cap)
308
309/**
310 * struct spi_mem_driver - SPI memory driver
311 * @spidrv: inherit from a SPI driver
312 * @probe: probe a SPI memory. Usually where detection/initialization takes
313 * place
314 * @remove: remove a SPI memory
315 * @shutdown: take appropriate action when the system is shutdown
316 *
317 * This is just a thin wrapper around a spi_driver. The core takes care of
318 * allocating the spi_mem object and forwarding the probe/remove/shutdown
319 * request to the spi_mem_driver. The reason we use this wrapper is because
320 * we might have to stuff more information into the spi_mem struct to let
321 * SPI controllers know more about the SPI memory they interact with, and
322 * having this intermediate layer allows us to do that without adding more
323 * useless fields to the spi_device object.
324 */
325struct spi_mem_driver {
326 struct spi_driver spidrv;
327 int (*probe)(struct spi_mem *mem);
328 int (*remove)(struct spi_mem *mem);
329 void (*shutdown)(struct spi_mem *mem);
330};
331
332#if IS_ENABLED(CONFIG_SPI_MEM)
333int spi_controller_dma_map_mem_op_data(struct spi_controller *ctlr,
334 const struct spi_mem_op *op,
335 struct sg_table *sg);
336
337void spi_controller_dma_unmap_mem_op_data(struct spi_controller *ctlr,
338 const struct spi_mem_op *op,
339 struct sg_table *sg);
340
341bool spi_mem_default_supports_op(struct spi_mem *mem,
342 const struct spi_mem_op *op);
343#else
344static inline int
345spi_controller_dma_map_mem_op_data(struct spi_controller *ctlr,
346 const struct spi_mem_op *op,
347 struct sg_table *sg)
348{
349 return -ENOTSUPP;
350}
351
352static inline void
353spi_controller_dma_unmap_mem_op_data(struct spi_controller *ctlr,
354 const struct spi_mem_op *op,
355 struct sg_table *sg)
356{
357}
358
359static inline
360bool spi_mem_default_supports_op(struct spi_mem *mem,
361 const struct spi_mem_op *op)
362{
363 return false;
364}
365#endif /* CONFIG_SPI_MEM */
366
367int spi_mem_adjust_op_size(struct spi_mem *mem, struct spi_mem_op *op);
368
369bool spi_mem_supports_op(struct spi_mem *mem,
370 const struct spi_mem_op *op);
371
372int spi_mem_exec_op(struct spi_mem *mem,
373 const struct spi_mem_op *op);
374
375const char *spi_mem_get_name(struct spi_mem *mem);
376
377struct spi_mem_dirmap_desc *
378spi_mem_dirmap_create(struct spi_mem *mem,
379 const struct spi_mem_dirmap_info *info);
380void spi_mem_dirmap_destroy(struct spi_mem_dirmap_desc *desc);
381ssize_t spi_mem_dirmap_read(struct spi_mem_dirmap_desc *desc,
382 u64 offs, size_t len, void *buf);
383ssize_t spi_mem_dirmap_write(struct spi_mem_dirmap_desc *desc,
384 u64 offs, size_t len, const void *buf);
385struct spi_mem_dirmap_desc *
386devm_spi_mem_dirmap_create(struct device *dev, struct spi_mem *mem,
387 const struct spi_mem_dirmap_info *info);
388void devm_spi_mem_dirmap_destroy(struct device *dev,
389 struct spi_mem_dirmap_desc *desc);
390
391int spi_mem_poll_status(struct spi_mem *mem,
392 const struct spi_mem_op *op,
393 u16 mask, u16 match,
394 unsigned long initial_delay_us,
395 unsigned long polling_delay_us,
396 u16 timeout_ms);
397
398int spi_mem_driver_register_with_owner(struct spi_mem_driver *drv,
399 struct module *owner);
400
401void spi_mem_driver_unregister(struct spi_mem_driver *drv);
402
403#define spi_mem_driver_register(__drv) \
404 spi_mem_driver_register_with_owner(__drv, THIS_MODULE)
405
406#define module_spi_mem_driver(__drv) \
407 module_driver(__drv, spi_mem_driver_register, \
408 spi_mem_driver_unregister)
409
410#endif /* __LINUX_SPI_MEM_H */
411

source code of linux/include/linux/spi/spi-mem.h