spi-mem.h

  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		.nbytes = 1,					\
 19		.buswidth = __buswidth,				\
 20		.opcode = __opcode,				\
 21	}
 22
 23#define SPI_MEM_DTR_OP_CMD(__opcode, __buswidth)		\
 24	{							\
 25		.nbytes = 1,					\
 26		.opcode = __opcode,				\
 27		.buswidth = __buswidth,				\
 28		.dtr = true,					\
 29	}
 30
 31#define SPI_MEM_OP_ADDR(__nbytes, __val, __buswidth)		\
 32	{							\
 33		.nbytes = __nbytes,				\
 34		.buswidth = __buswidth,				\
 35		.val = __val,					\
 36	}
 37
 38#define SPI_MEM_DTR_OP_ADDR(__nbytes, __val, __buswidth)	\
 39	{							\
 40		.nbytes = __nbytes,				\
 41		.val = __val,					\
 42		.buswidth = __buswidth,				\
 43		.dtr = true,					\
 44	}
 45
 46#define SPI_MEM_OP_NO_ADDR	{ }
 47
 48#define SPI_MEM_OP_DUMMY(__nbytes, __buswidth)			\
 49	{							\
 50		.nbytes = __nbytes,				\
 51		.buswidth = __buswidth,				\
 52	}
 53
 54#define SPI_MEM_DTR_OP_DUMMY(__nbytes, __buswidth)		\
 55	{							\
 56		.nbytes = __nbytes,				\
 57		.buswidth = __buswidth,				\
 58		.dtr = true,					\
 59	}
 60
 61#define SPI_MEM_OP_NO_DUMMY	{ }
 62
 63#define SPI_MEM_OP_DATA_IN(__nbytes, __buf, __buswidth)		\
 64	{							\
 65		.buswidth = __buswidth,				\
 66		.dir = SPI_MEM_DATA_IN,				\
 67		.nbytes = __nbytes,				\
 68		.buf.in = __buf,				\
 69	}
 70
 71#define SPI_MEM_DTR_OP_DATA_IN(__nbytes, __buf, __buswidth)	\
 72	{							\
 73		.dir = SPI_MEM_DATA_IN,				\
 74		.nbytes = __nbytes,				\
 75		.buf.in = __buf,				\
 76		.buswidth = __buswidth,				\
 77		.dtr = true,					\
 78	}
 79
 80#define SPI_MEM_OP_DATA_OUT(__nbytes, __buf, __buswidth)	\
 81	{							\
 82		.buswidth = __buswidth,				\
 83		.dir = SPI_MEM_DATA_OUT,			\
 84		.nbytes = __nbytes,				\
 85		.buf.out = __buf,				\
 86	}
 87
 88#define SPI_MEM_DTR_OP_DATA_OUT(__nbytes, __buf, __buswidth)	\
 89	{							\
 90		.dir = SPI_MEM_DATA_OUT,			\
 91		.nbytes = __nbytes,				\
 92		.buf.out = __buf,				\
 93		.buswidth = __buswidth,				\
 94		.dtr = true,					\
 95	}
 96
 97#define SPI_MEM_OP_NO_DATA	{ }
 98
 99/**
100 * enum spi_mem_data_dir - describes the direction of a SPI memory data
101 *			   transfer from the controller perspective
102 * @SPI_MEM_NO_DATA: no data transferred
103 * @SPI_MEM_DATA_IN: data coming from the SPI memory
104 * @SPI_MEM_DATA_OUT: data sent to the SPI memory
105 */
106enum spi_mem_data_dir {
107	SPI_MEM_NO_DATA,
108	SPI_MEM_DATA_IN,
109	SPI_MEM_DATA_OUT,
110};
111
112#define SPI_MEM_OP_MAX_FREQ(__freq)				\
113	.max_freq = __freq
114
115/**
116 * struct spi_mem_op - describes a SPI memory operation
117 * @cmd.nbytes: number of opcode bytes (only 1 or 2 are valid). The opcode is
118 *		sent MSB-first.
119 * @cmd.buswidth: number of IO lines used to transmit the command
120 * @cmd.opcode: operation opcode
121 * @cmd.dtr: whether the command opcode should be sent in DTR mode or not
122 * @addr.nbytes: number of address bytes to send. Can be zero if the operation
123 *		 does not need to send an address
124 * @addr.buswidth: number of IO lines used to transmit the address cycles
125 * @addr.dtr: whether the address should be sent in DTR mode or not
126 * @addr.val: address value. This value is always sent MSB first on the bus.
127 *	      Note that only @addr.nbytes are taken into account in this
128 *	      address value, so users should make sure the value fits in the
129 *	      assigned number of bytes.
130 * @dummy.nbytes: number of dummy bytes to send after an opcode or address. Can
131 *		  be zero if the operation does not require dummy bytes
132 * @dummy.buswidth: number of IO lanes used to transmit the dummy bytes
133 * @dummy.dtr: whether the dummy bytes should be sent in DTR mode or not
134 * @data.buswidth: number of IO lanes used to send/receive the data
135 * @data.dtr: whether the data should be sent in DTR mode or not
136 * @data.ecc: whether error correction is required or not
137 * @data.swap16: whether the byte order of 16-bit words is swapped when read
138 *		 or written in Octal DTR mode compared to STR mode.
139 * @data.dir: direction of the transfer
140 * @data.nbytes: number of data bytes to send/receive. Can be zero if the
141 *		 operation does not involve transferring data
142 * @data.buf.in: input buffer (must be DMA-able)
143 * @data.buf.out: output buffer (must be DMA-able)
144 * @max_freq: frequency limitation wrt this operation. 0 means there is no
145 *	      specific constraint and the highest achievable frequency can be
146 *	      attempted.
147 */
148struct spi_mem_op {
149	struct {
150		u8 nbytes;
151		u8 buswidth;
152		u8 dtr : 1;
153		u8 __pad : 7;
154		u16 opcode;
155	} cmd;
156
157	struct {
158		u8 nbytes;
159		u8 buswidth;
160		u8 dtr : 1;
161		u8 __pad : 7;
162		u64 val;
163	} addr;
164
165	struct {
166		u8 nbytes;
167		u8 buswidth;
168		u8 dtr : 1;
169		u8 __pad : 7;
170	} dummy;
171
172	struct {
173		u8 buswidth;
174		u8 dtr : 1;
175		u8 ecc : 1;
176		u8 swap16 : 1;
177		u8 __pad : 5;
178		enum spi_mem_data_dir dir;
179		unsigned int nbytes;
180		union {
181			void *in;
182			const void *out;
183		} buf;
184	} data;
185
186	unsigned int max_freq;
187};
188
189#define SPI_MEM_OP(__cmd, __addr, __dummy, __data, ...)		\
190	{							\
191		.cmd = __cmd,					\
192		.addr = __addr,					\
193		.dummy = __dummy,				\
194		.data = __data,					\
195		__VA_ARGS__					\
196	}
197
198/**
199 * struct spi_mem_dirmap_info - Direct mapping information
200 * @op_tmpl: operation template that should be used by the direct mapping when
201 *	     the memory device is accessed
202 * @offset: absolute offset this direct mapping is pointing to
203 * @length: length in byte of this direct mapping
204 *
205 * These information are used by the controller specific implementation to know
206 * the portion of memory that is directly mapped and the spi_mem_op that should
207 * be used to access the device.
208 * A direct mapping is only valid for one direction (read or write) and this
209 * direction is directly encoded in the ->op_tmpl.data.dir field.
210 */
211struct spi_mem_dirmap_info {
212	struct spi_mem_op op_tmpl;
213	u64 offset;
214	u64 length;
215};
216
217/**
218 * struct spi_mem_dirmap_desc - Direct mapping descriptor
219 * @mem: the SPI memory device this direct mapping is attached to
220 * @info: information passed at direct mapping creation time
221 * @nodirmap: set to 1 if the SPI controller does not implement
222 *	      ->mem_ops->dirmap_create() or when this function returned an
223 *	      error. If @nodirmap is true, all spi_mem_dirmap_{read,write}()
224 *	      calls will use spi_mem_exec_op() to access the memory. This is a
225 *	      degraded mode that allows spi_mem drivers to use the same code
226 *	      no matter whether the controller supports direct mapping or not
227 * @priv: field pointing to controller specific data
228 *
229 * Common part of a direct mapping descriptor. This object is created by
230 * spi_mem_dirmap_create() and controller implementation of ->create_dirmap()
231 * can create/attach direct mapping resources to the descriptor in the ->priv
232 * field.
233 */
234struct spi_mem_dirmap_desc {
235	struct spi_mem *mem;
236	struct spi_mem_dirmap_info info;
237	unsigned int nodirmap;
238	void *priv;
239};
240
241/**
242 * struct spi_mem - describes a SPI memory device
243 * @spi: the underlying SPI device
244 * @drvpriv: spi_mem_driver private data
245 * @name: name of the SPI memory device
246 *
247 * Extra information that describe the SPI memory device and may be needed by
248 * the controller to properly handle this device should be placed here.
249 *
250 * One example would be the device size since some controller expose their SPI
251 * mem devices through a io-mapped region.
252 */
253struct spi_mem {
254	struct spi_device *spi;
255	void *drvpriv;
256	const char *name;
257};
258
259/**
260 * struct spi_mem_set_drvdata() - attach driver private data to a SPI mem
261 *				  device
262 * @mem: memory device
263 * @data: data to attach to the memory device
264 */
265static inline void spi_mem_set_drvdata(struct spi_mem *mem, void *data)
266{
267	mem->drvpriv = data;
268}
269
270/**
271 * struct spi_mem_get_drvdata() - get driver private data attached to a SPI mem
272 *				  device
273 * @mem: memory device
274 *
275 * Return: the data attached to the mem device.
276 */
277static inline void *spi_mem_get_drvdata(struct spi_mem *mem)
278{
279	return mem->drvpriv;
280}
281
282/**
283 * struct spi_controller_mem_ops - SPI memory operations
284 * @adjust_op_size: shrink the data xfer of an operation to match controller's
285 *		    limitations (can be alignment or max RX/TX size
286 *		    limitations)
287 * @supports_op: check if an operation is supported by the controller
288 * @exec_op: execute a SPI memory operation
289 *           not all driver provides supports_op(), so it can return -EOPNOTSUPP
290 *           if the op is not supported by the driver/controller
291 * @get_name: get a custom name for the SPI mem device from the controller.
292 *	      This might be needed if the controller driver has been ported
293 *	      to use the SPI mem layer and a custom name is used to keep
294 *	      mtdparts compatible.
295 *	      Note that if the implementation of this function allocates memory
296 *	      dynamically, then it should do so with devm_xxx(), as we don't
297 *	      have a ->free_name() function.
298 * @dirmap_create: create a direct mapping descriptor that can later be used to
299 *		   access the memory device. This method is optional
300 * @dirmap_destroy: destroy a memory descriptor previous created by
301 *		    ->dirmap_create()
302 * @dirmap_read: read data from the memory device using the direct mapping
303 *		 created by ->dirmap_create(). The function can return less
304 *		 data than requested (for example when the request is crossing
305 *		 the currently mapped area), and the caller of
306 *		 spi_mem_dirmap_read() is responsible for calling it again in
307 *		 this case.
308 * @dirmap_write: write data to the memory device using the direct mapping
309 *		  created by ->dirmap_create(). The function can return less
310 *		  data than requested (for example when the request is crossing
311 *		  the currently mapped area), and the caller of
312 *		  spi_mem_dirmap_write() is responsible for calling it again in
313 *		  this case.
314 * @poll_status: poll memory device status until (status & mask) == match or
315 *               when the timeout has expired. It fills the data buffer with
316 *               the last status value.
317 *
318 * This interface should be implemented by SPI controllers providing an
319 * high-level interface to execute SPI memory operation, which is usually the
320 * case for QSPI controllers.
321 *
322 * Note on ->dirmap_{read,write}(): drivers should avoid accessing the direct
323 * mapping from the CPU because doing that can stall the CPU waiting for the
324 * SPI mem transaction to finish, and this will make real-time maintainers
325 * unhappy and might make your system less reactive. Instead, drivers should
326 * use DMA to access this direct mapping.
327 */
328struct spi_controller_mem_ops {
329	int (*adjust_op_size)(struct spi_mem *mem, struct spi_mem_op *op);
330	bool (*supports_op)(struct spi_mem *mem,
331			    const struct spi_mem_op *op);
332	int (*exec_op)(struct spi_mem *mem,
333		       const struct spi_mem_op *op);
334	const char *(*get_name)(struct spi_mem *mem);
335	int (*dirmap_create)(struct spi_mem_dirmap_desc *desc);
336	void (*dirmap_destroy)(struct spi_mem_dirmap_desc *desc);
337	ssize_t (*dirmap_read)(struct spi_mem_dirmap_desc *desc,
338			       u64 offs, size_t len, void *buf);
339	ssize_t (*dirmap_write)(struct spi_mem_dirmap_desc *desc,
340				u64 offs, size_t len, const void *buf);
341	int (*poll_status)(struct spi_mem *mem,
342			   const struct spi_mem_op *op,
343			   u16 mask, u16 match,
344			   unsigned long initial_delay_us,
345			   unsigned long polling_rate_us,
346			   unsigned long timeout_ms);
347};
348
349/**
350 * struct spi_controller_mem_caps - SPI memory controller capabilities
351 * @dtr: Supports DTR operations
352 * @ecc: Supports operations with error correction
353 * @swap16: Supports swapping bytes on a 16 bit boundary when configured in
354 *	    Octal DTR
355 * @per_op_freq: Supports per operation frequency switching
356 */
357struct spi_controller_mem_caps {
358	bool dtr;
359	bool ecc;
360	bool swap16;
361	bool per_op_freq;
362};
363
364#define spi_mem_controller_is_capable(ctlr, cap)	\
365	((ctlr)->mem_caps && (ctlr)->mem_caps->cap)
366
367/**
368 * struct spi_mem_driver - SPI memory driver
369 * @spidrv: inherit from a SPI driver
370 * @probe: probe a SPI memory. Usually where detection/initialization takes
371 *	   place
372 * @remove: remove a SPI memory
373 * @shutdown: take appropriate action when the system is shutdown
374 *
375 * This is just a thin wrapper around a spi_driver. The core takes care of
376 * allocating the spi_mem object and forwarding the probe/remove/shutdown
377 * request to the spi_mem_driver. The reason we use this wrapper is because
378 * we might have to stuff more information into the spi_mem struct to let
379 * SPI controllers know more about the SPI memory they interact with, and
380 * having this intermediate layer allows us to do that without adding more
381 * useless fields to the spi_device object.
382 */
383struct spi_mem_driver {
384	struct spi_driver spidrv;
385	int (*probe)(struct spi_mem *mem);
386	int (*remove)(struct spi_mem *mem);
387	void (*shutdown)(struct spi_mem *mem);
388};
389
390#if IS_ENABLED(CONFIG_SPI_MEM)
391int spi_controller_dma_map_mem_op_data(struct spi_controller *ctlr,
392				       const struct spi_mem_op *op,
393				       struct sg_table *sg);
394
395void spi_controller_dma_unmap_mem_op_data(struct spi_controller *ctlr,
396					  const struct spi_mem_op *op,
397					  struct sg_table *sg);
398
399bool spi_mem_default_supports_op(struct spi_mem *mem,
400				 const struct spi_mem_op *op);
401#else
402static inline int
403spi_controller_dma_map_mem_op_data(struct spi_controller *ctlr,
404				   const struct spi_mem_op *op,
405				   struct sg_table *sg)
406{
407	return -ENOTSUPP;
408}
409
410static inline void
411spi_controller_dma_unmap_mem_op_data(struct spi_controller *ctlr,
412				     const struct spi_mem_op *op,
413				     struct sg_table *sg)
414{
415}
416
417static inline
418bool spi_mem_default_supports_op(struct spi_mem *mem,
419				 const struct spi_mem_op *op)
420{
421	return false;
422}
423#endif /* CONFIG_SPI_MEM */
424
425int spi_mem_adjust_op_size(struct spi_mem *mem, struct spi_mem_op *op);
426void spi_mem_adjust_op_freq(struct spi_mem *mem, struct spi_mem_op *op);
427u64 spi_mem_calc_op_duration(struct spi_mem *mem, struct spi_mem_op *op);
428
429bool spi_mem_supports_op(struct spi_mem *mem,
430			 const struct spi_mem_op *op);
431
432int spi_mem_exec_op(struct spi_mem *mem,
433		    const struct spi_mem_op *op);
434
435const char *spi_mem_get_name(struct spi_mem *mem);
436
437struct spi_mem_dirmap_desc *
438spi_mem_dirmap_create(struct spi_mem *mem,
439		      const struct spi_mem_dirmap_info *info);
440void spi_mem_dirmap_destroy(struct spi_mem_dirmap_desc *desc);
441ssize_t spi_mem_dirmap_read(struct spi_mem_dirmap_desc *desc,
442			    u64 offs, size_t len, void *buf);
443ssize_t spi_mem_dirmap_write(struct spi_mem_dirmap_desc *desc,
444			     u64 offs, size_t len, const void *buf);
445struct spi_mem_dirmap_desc *
446devm_spi_mem_dirmap_create(struct device *dev, struct spi_mem *mem,
447			   const struct spi_mem_dirmap_info *info);
448void devm_spi_mem_dirmap_destroy(struct device *dev,
449				 struct spi_mem_dirmap_desc *desc);
450
451int spi_mem_poll_status(struct spi_mem *mem,
452			const struct spi_mem_op *op,
453			u16 mask, u16 match,
454			unsigned long initial_delay_us,
455			unsigned long polling_delay_us,
456			u16 timeout_ms);
457
458int spi_mem_driver_register_with_owner(struct spi_mem_driver *drv,
459				       struct module *owner);
460
461void spi_mem_driver_unregister(struct spi_mem_driver *drv);
462
463#define spi_mem_driver_register(__drv)                                  \
464	spi_mem_driver_register_with_owner(__drv, THIS_MODULE)
465
466#define module_spi_mem_driver(__drv)                                    \
467	module_driver(__drv, spi_mem_driver_register,                   \
468		      spi_mem_driver_unregister)
469
470#endif /* __LINUX_SPI_MEM_H */