1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * Counter interface
4  * Copyright (C) 2018 William Breathitt Gray
5  */
6 #ifndef _COUNTER_H_
7 #define _COUNTER_H_
8 
9 #include <linux/counter_enum.h>
10 #include <linux/device.h>
11 #include <linux/types.h>
12 
13 enum counter_count_direction {
14 	COUNTER_COUNT_DIRECTION_FORWARD = 0,
15 	COUNTER_COUNT_DIRECTION_BACKWARD
16 };
17 extern const char *const counter_count_direction_str[2];
18 
19 enum counter_count_mode {
20 	COUNTER_COUNT_MODE_NORMAL = 0,
21 	COUNTER_COUNT_MODE_RANGE_LIMIT,
22 	COUNTER_COUNT_MODE_NON_RECYCLE,
23 	COUNTER_COUNT_MODE_MODULO_N
24 };
25 extern const char *const counter_count_mode_str[4];
26 
27 struct counter_device;
28 struct counter_signal;
29 
30 /**
31  * struct counter_signal_ext - Counter Signal extensions
32  * @name:	attribute name
33  * @read:	read callback for this attribute; may be NULL
34  * @write:	write callback for this attribute; may be NULL
35  * @priv:	data private to the driver
36  */
37 struct counter_signal_ext {
38 	const char *name;
39 	ssize_t (*read)(struct counter_device *counter,
40 			struct counter_signal *signal, void *priv, char *buf);
41 	ssize_t (*write)(struct counter_device *counter,
42 			 struct counter_signal *signal, void *priv,
43 			 const char *buf, size_t len);
44 	void *priv;
45 };
46 
47 /**
48  * struct counter_signal - Counter Signal node
49  * @id:		unique ID used to identify signal
50  * @name:	device-specific Signal name; ideally, this should match the name
51  *		as it appears in the datasheet documentation
52  * @ext:	optional array of Counter Signal extensions
53  * @num_ext:	number of Counter Signal extensions specified in @ext
54  * @priv:	optional private data supplied by driver
55  */
56 struct counter_signal {
57 	int id;
58 	const char *name;
59 
60 	const struct counter_signal_ext *ext;
61 	size_t num_ext;
62 
63 	void *priv;
64 };
65 
66 /**
67  * struct counter_signal_enum_ext - Signal enum extension attribute
68  * @items:	Array of strings
69  * @num_items:	Number of items specified in @items
70  * @set:	Set callback function; may be NULL
71  * @get:	Get callback function; may be NULL
72  *
73  * The counter_signal_enum_ext structure can be used to implement enum style
74  * Signal extension attributes. Enum style attributes are those which have a set
75  * of strings that map to unsigned integer values. The Generic Counter Signal
76  * enum extension helper code takes care of mapping between value and string, as
77  * well as generating a "_available" file which contains a list of all available
78  * items. The get callback is used to query the currently active item; the index
79  * of the item within the respective items array is returned via the 'item'
80  * parameter. The set callback is called when the attribute is updated; the
81  * 'item' parameter contains the index of the newly activated item within the
82  * respective items array.
83  */
84 struct counter_signal_enum_ext {
85 	const char * const *items;
86 	size_t num_items;
87 	int (*get)(struct counter_device *counter,
88 		   struct counter_signal *signal, size_t *item);
89 	int (*set)(struct counter_device *counter,
90 		   struct counter_signal *signal, size_t item);
91 };
92 
93 /**
94  * COUNTER_SIGNAL_ENUM() - Initialize Signal enum extension
95  * @_name:	Attribute name
96  * @_e:		Pointer to a counter_signal_enum_ext structure
97  *
98  * This should usually be used together with COUNTER_SIGNAL_ENUM_AVAILABLE()
99  */
100 #define COUNTER_SIGNAL_ENUM(_name, _e) \
101 { \
102 	.name = (_name), \
103 	.read = counter_signal_enum_read, \
104 	.write = counter_signal_enum_write, \
105 	.priv = (_e) \
106 }
107 
108 /**
109  * COUNTER_SIGNAL_ENUM_AVAILABLE() - Initialize Signal enum available extension
110  * @_name:	Attribute name ("_available" will be appended to the name)
111  * @_e:		Pointer to a counter_signal_enum_ext structure
112  *
113  * Creates a read only attribute that lists all the available enum items in a
114  * newline separated list. This should usually be used together with
115  * COUNTER_SIGNAL_ENUM()
116  */
117 #define COUNTER_SIGNAL_ENUM_AVAILABLE(_name, _e) \
118 { \
119 	.name = (_name "_available"), \
120 	.read = counter_signal_enum_available_read, \
121 	.priv = (_e) \
122 }
123 
124 enum counter_synapse_action {
125 	COUNTER_SYNAPSE_ACTION_NONE = 0,
126 	COUNTER_SYNAPSE_ACTION_RISING_EDGE,
127 	COUNTER_SYNAPSE_ACTION_FALLING_EDGE,
128 	COUNTER_SYNAPSE_ACTION_BOTH_EDGES
129 };
130 
131 /**
132  * struct counter_synapse - Counter Synapse node
133  * @action:		index of current action mode
134  * @actions_list:	array of available action modes
135  * @num_actions:	number of action modes specified in @actions_list
136  * @signal:		pointer to associated signal
137  */
138 struct counter_synapse {
139 	size_t action;
140 	const enum counter_synapse_action *actions_list;
141 	size_t num_actions;
142 
143 	struct counter_signal *signal;
144 };
145 
146 struct counter_count;
147 
148 /**
149  * struct counter_count_ext - Counter Count extension
150  * @name:	attribute name
151  * @read:	read callback for this attribute; may be NULL
152  * @write:	write callback for this attribute; may be NULL
153  * @priv:	data private to the driver
154  */
155 struct counter_count_ext {
156 	const char *name;
157 	ssize_t (*read)(struct counter_device *counter,
158 			struct counter_count *count, void *priv, char *buf);
159 	ssize_t (*write)(struct counter_device *counter,
160 			 struct counter_count *count, void *priv,
161 			 const char *buf, size_t len);
162 	void *priv;
163 };
164 
165 enum counter_count_function {
166 	COUNTER_COUNT_FUNCTION_INCREASE = 0,
167 	COUNTER_COUNT_FUNCTION_DECREASE,
168 	COUNTER_COUNT_FUNCTION_PULSE_DIRECTION,
169 	COUNTER_COUNT_FUNCTION_QUADRATURE_X1_A,
170 	COUNTER_COUNT_FUNCTION_QUADRATURE_X1_B,
171 	COUNTER_COUNT_FUNCTION_QUADRATURE_X2_A,
172 	COUNTER_COUNT_FUNCTION_QUADRATURE_X2_B,
173 	COUNTER_COUNT_FUNCTION_QUADRATURE_X4
174 };
175 
176 /**
177  * struct counter_count - Counter Count node
178  * @id:			unique ID used to identify Count
179  * @name:		device-specific Count name; ideally, this should match
180  *			the name as it appears in the datasheet documentation
181  * @function:		index of current function mode
182  * @functions_list:	array available function modes
183  * @num_functions:	number of function modes specified in @functions_list
184  * @synapses:		array of synapses for initialization
185  * @num_synapses:	number of synapses specified in @synapses
186  * @ext:		optional array of Counter Count extensions
187  * @num_ext:		number of Counter Count extensions specified in @ext
188  * @priv:		optional private data supplied by driver
189  */
190 struct counter_count {
191 	int id;
192 	const char *name;
193 
194 	size_t function;
195 	const enum counter_count_function *functions_list;
196 	size_t num_functions;
197 
198 	struct counter_synapse *synapses;
199 	size_t num_synapses;
200 
201 	const struct counter_count_ext *ext;
202 	size_t num_ext;
203 
204 	void *priv;
205 };
206 
207 /**
208  * struct counter_count_enum_ext - Count enum extension attribute
209  * @items:	Array of strings
210  * @num_items:	Number of items specified in @items
211  * @set:	Set callback function; may be NULL
212  * @get:	Get callback function; may be NULL
213  *
214  * The counter_count_enum_ext structure can be used to implement enum style
215  * Count extension attributes. Enum style attributes are those which have a set
216  * of strings that map to unsigned integer values. The Generic Counter Count
217  * enum extension helper code takes care of mapping between value and string, as
218  * well as generating a "_available" file which contains a list of all available
219  * items. The get callback is used to query the currently active item; the index
220  * of the item within the respective items array is returned via the 'item'
221  * parameter. The set callback is called when the attribute is updated; the
222  * 'item' parameter contains the index of the newly activated item within the
223  * respective items array.
224  */
225 struct counter_count_enum_ext {
226 	const char * const *items;
227 	size_t num_items;
228 	int (*get)(struct counter_device *counter, struct counter_count *count,
229 		   size_t *item);
230 	int (*set)(struct counter_device *counter, struct counter_count *count,
231 		   size_t item);
232 };
233 
234 /**
235  * COUNTER_COUNT_ENUM() - Initialize Count enum extension
236  * @_name:	Attribute name
237  * @_e:		Pointer to a counter_count_enum_ext structure
238  *
239  * This should usually be used together with COUNTER_COUNT_ENUM_AVAILABLE()
240  */
241 #define COUNTER_COUNT_ENUM(_name, _e) \
242 { \
243 	.name = (_name), \
244 	.read = counter_count_enum_read, \
245 	.write = counter_count_enum_write, \
246 	.priv = (_e) \
247 }
248 
249 /**
250  * COUNTER_COUNT_ENUM_AVAILABLE() - Initialize Count enum available extension
251  * @_name:	Attribute name ("_available" will be appended to the name)
252  * @_e:		Pointer to a counter_count_enum_ext structure
253  *
254  * Creates a read only attribute that lists all the available enum items in a
255  * newline separated list. This should usually be used together with
256  * COUNTER_COUNT_ENUM()
257  */
258 #define COUNTER_COUNT_ENUM_AVAILABLE(_name, _e) \
259 { \
260 	.name = (_name "_available"), \
261 	.read = counter_count_enum_available_read, \
262 	.priv = (_e) \
263 }
264 
265 /**
266  * struct counter_device_attr_group - internal container for attribute group
267  * @attr_group:	Counter sysfs attributes group
268  * @attr_list:	list to keep track of created Counter sysfs attributes
269  * @num_attr:	number of Counter sysfs attributes
270  */
271 struct counter_device_attr_group {
272 	struct attribute_group attr_group;
273 	struct list_head attr_list;
274 	size_t num_attr;
275 };
276 
277 /**
278  * struct counter_device_state - internal state container for a Counter device
279  * @id:			unique ID used to identify the Counter
280  * @dev:		internal device structure
281  * @groups_list:	attribute groups list (for Signals, Counts, and ext)
282  * @num_groups:		number of attribute groups containers
283  * @groups:		Counter sysfs attribute groups (to populate @dev.groups)
284  */
285 struct counter_device_state {
286 	int id;
287 	struct device dev;
288 	struct counter_device_attr_group *groups_list;
289 	size_t num_groups;
290 	const struct attribute_group **groups;
291 };
292 
293 /**
294  * struct counter_signal_read_value - Opaque Signal read value
295  * @buf:	string representation of Signal read value
296  * @len:	length of string in @buf
297  */
298 struct counter_signal_read_value {
299 	char *buf;
300 	size_t len;
301 };
302 
303 /**
304  * struct counter_count_read_value - Opaque Count read value
305  * @buf:	string representation of Count read value
306  * @len:	length of string in @buf
307  */
308 struct counter_count_read_value {
309 	char *buf;
310 	size_t len;
311 };
312 
313 /**
314  * struct counter_count_write_value - Opaque Count write value
315  * @buf:	string representation of Count write value
316  */
317 struct counter_count_write_value {
318 	const char *buf;
319 };
320 
321 /**
322  * struct counter_ops - Callbacks from driver
323  * @signal_read:	optional read callback for Signal attribute. The read
324  *			value of the respective Signal should be passed back via
325  *			the val parameter. val points to an opaque type which
326  *			should be set only by calling the
327  *			counter_signal_read_value_set function from within the
328  *			signal_read callback.
329  * @count_read:		optional read callback for Count attribute. The read
330  *			value of the respective Count should be passed back via
331  *			the val parameter. val points to an opaque type which
332  *			should be set only by calling the
333  *			counter_count_read_value_set function from within the
334  *			count_read callback.
335  * @count_write:	optional write callback for Count attribute. The write
336  *			value for the respective Count is passed in via the val
337  *			parameter. val points to an opaque type which should be
338  *			accessed only by calling the
339  *			counter_count_write_value_get function.
340  * @function_get:	function to get the current count function mode. Returns
341  *			0 on success and negative error code on error. The index
342  *			of the respective Count's returned function mode should
343  *			be passed back via the function parameter.
344  * @function_set:	function to set the count function mode. function is the
345  *			index of the requested function mode from the respective
346  *			Count's functions_list array.
347  * @action_get:		function to get the current action mode. Returns 0 on
348  *			success and negative error code on error. The index of
349  *			the respective Signal's returned action mode should be
350  *			passed back via the action parameter.
351  * @action_set:		function to set the action mode. action is the index of
352  *			the requested action mode from the respective Synapse's
353  *			actions_list array.
354  */
355 struct counter_ops {
356 	int (*signal_read)(struct counter_device *counter,
357 			   struct counter_signal *signal,
358 			   struct counter_signal_read_value *val);
359 	int (*count_read)(struct counter_device *counter,
360 			  struct counter_count *count,
361 			  struct counter_count_read_value *val);
362 	int (*count_write)(struct counter_device *counter,
363 			   struct counter_count *count,
364 			   struct counter_count_write_value *val);
365 	int (*function_get)(struct counter_device *counter,
366 			    struct counter_count *count, size_t *function);
367 	int (*function_set)(struct counter_device *counter,
368 			    struct counter_count *count, size_t function);
369 	int (*action_get)(struct counter_device *counter,
370 			  struct counter_count *count,
371 			  struct counter_synapse *synapse, size_t *action);
372 	int (*action_set)(struct counter_device *counter,
373 			  struct counter_count *count,
374 			  struct counter_synapse *synapse, size_t action);
375 };
376 
377 /**
378  * struct counter_device_ext - Counter device extension
379  * @name:	attribute name
380  * @read:	read callback for this attribute; may be NULL
381  * @write:	write callback for this attribute; may be NULL
382  * @priv:	data private to the driver
383  */
384 struct counter_device_ext {
385 	const char *name;
386 	ssize_t (*read)(struct counter_device *counter, void *priv, char *buf);
387 	ssize_t (*write)(struct counter_device *counter, void *priv,
388 			 const char *buf, size_t len);
389 	void *priv;
390 };
391 
392 /**
393  * struct counter_device_enum_ext - Counter enum extension attribute
394  * @items:	Array of strings
395  * @num_items:	Number of items specified in @items
396  * @set:	Set callback function; may be NULL
397  * @get:	Get callback function; may be NULL
398  *
399  * The counter_device_enum_ext structure can be used to implement enum style
400  * Counter extension attributes. Enum style attributes are those which have a
401  * set of strings that map to unsigned integer values. The Generic Counter enum
402  * extension helper code takes care of mapping between value and string, as well
403  * as generating a "_available" file which contains a list of all available
404  * items. The get callback is used to query the currently active item; the index
405  * of the item within the respective items array is returned via the 'item'
406  * parameter. The set callback is called when the attribute is updated; the
407  * 'item' parameter contains the index of the newly activated item within the
408  * respective items array.
409  */
410 struct counter_device_enum_ext {
411 	const char * const *items;
412 	size_t num_items;
413 	int (*get)(struct counter_device *counter, size_t *item);
414 	int (*set)(struct counter_device *counter, size_t item);
415 };
416 
417 /**
418  * COUNTER_DEVICE_ENUM() - Initialize Counter enum extension
419  * @_name:	Attribute name
420  * @_e:		Pointer to a counter_device_enum_ext structure
421  *
422  * This should usually be used together with COUNTER_DEVICE_ENUM_AVAILABLE()
423  */
424 #define COUNTER_DEVICE_ENUM(_name, _e) \
425 { \
426 	.name = (_name), \
427 	.read = counter_device_enum_read, \
428 	.write = counter_device_enum_write, \
429 	.priv = (_e) \
430 }
431 
432 /**
433  * COUNTER_DEVICE_ENUM_AVAILABLE() - Initialize Counter enum available extension
434  * @_name:	Attribute name ("_available" will be appended to the name)
435  * @_e:		Pointer to a counter_device_enum_ext structure
436  *
437  * Creates a read only attribute that lists all the available enum items in a
438  * newline separated list. This should usually be used together with
439  * COUNTER_DEVICE_ENUM()
440  */
441 #define COUNTER_DEVICE_ENUM_AVAILABLE(_name, _e) \
442 { \
443 	.name = (_name "_available"), \
444 	.read = counter_device_enum_available_read, \
445 	.priv = (_e) \
446 }
447 
448 /**
449  * struct counter_device - Counter data structure
450  * @name:		name of the device as it appears in the datasheet
451  * @parent:		optional parent device providing the counters
452  * @device_state:	internal device state container
453  * @ops:		callbacks from driver
454  * @signals:		array of Signals
455  * @num_signals:	number of Signals specified in @signals
456  * @counts:		array of Counts
457  * @num_counts:		number of Counts specified in @counts
458  * @ext:		optional array of Counter device extensions
459  * @num_ext:		number of Counter device extensions specified in @ext
460  * @priv:		optional private data supplied by driver
461  */
462 struct counter_device {
463 	const char *name;
464 	struct device *parent;
465 	struct counter_device_state *device_state;
466 
467 	const struct counter_ops *ops;
468 
469 	struct counter_signal *signals;
470 	size_t num_signals;
471 	struct counter_count *counts;
472 	size_t num_counts;
473 
474 	const struct counter_device_ext *ext;
475 	size_t num_ext;
476 
477 	void *priv;
478 };
479 
480 enum counter_signal_level {
481 	COUNTER_SIGNAL_LEVEL_LOW = 0,
482 	COUNTER_SIGNAL_LEVEL_HIGH
483 };
484 
485 enum counter_signal_value_type {
486 	COUNTER_SIGNAL_LEVEL = 0
487 };
488 
489 enum counter_count_value_type {
490 	COUNTER_COUNT_POSITION = 0,
491 };
492 
493 void counter_signal_read_value_set(struct counter_signal_read_value *const val,
494 				   const enum counter_signal_value_type type,
495 				   void *const data);
496 void counter_count_read_value_set(struct counter_count_read_value *const val,
497 				  const enum counter_count_value_type type,
498 				  void *const data);
499 int counter_count_write_value_get(void *const data,
500 				  const enum counter_count_value_type type,
501 				  const struct counter_count_write_value *const val);
502 
503 int counter_register(struct counter_device *const counter);
504 void counter_unregister(struct counter_device *const counter);
505 int devm_counter_register(struct device *dev,
506 			  struct counter_device *const counter);
507 void devm_counter_unregister(struct device *dev,
508 			     struct counter_device *const counter);
509 
510 #endif /* _COUNTER_H_ */
511