xref: /linux/drivers/comedi/drivers/ni_routes.h (revision cbac924200b838cfb8d8b1415113d788089dc50b)
1 /* SPDX-License-Identifier: GPL-2.0+ */
2 /*
3  *  comedi/drivers/ni_routes.h
4  *  Route information for NI boards.
5  *
6  *  COMEDI - Linux Control and Measurement Device Interface
7  *  Copyright (C) 2016 Spencer E. Olson <olsonse@umich.edu>
8  *
9  *  This program is free software; you can redistribute it and/or modify
10  *  it under the terms of the GNU General Public License as published by
11  *  the Free Software Foundation; either version 2 of the License, or
12  *  (at your option) any later version.
13  *
14  *  This program is distributed in the hope that it will be useful,
15  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
16  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17  *  GNU General Public License for more details.
18  */
19 
20 #ifndef _COMEDI_DRIVERS_NI_ROUTES_H
21 #define _COMEDI_DRIVERS_NI_ROUTES_H
22 
23 #include <linux/types.h>
24 #include <linux/errno.h>
25 
26 #ifndef NI_ROUTE_VALUE_EXTERNAL_CONVERSION
27 #include <linux/bitops.h>
28 #endif
29 
30 #include <linux/comedi.h>
31 
32 /**
33  * struct ni_route_set - Set of destinations with a common source.
34  * @dest: Destination of all sources in this route set.
35  * @n_src: Number of sources for this route set.
36  * @src: List of sources that all map to the same destination.
37  */
38 struct ni_route_set {
39 	int dest;
40 	int n_src;
41 	int *src;
42 };
43 
44 /**
45  * struct ni_device_routes - List of all src->dest sets for a particular device.
46  * @device: Name of board/device (e.g. pxi-6733).
47  * @n_route_sets: Number of route sets that are valid for this device.
48  * @routes: List of route sets that are valid for this device.
49  */
50 struct ni_device_routes {
51 	const char *device;
52 	int n_route_sets;
53 	struct ni_route_set *routes;
54 };
55 
56 /**
57  * struct ni_route_tables - Register values and valid routes for a device.
58  * @valid_routes: Pointer to a all valid route sets for a single device.
59  * @route_values: Pointer to register values for all routes for the family to
60  *		  which the device belongs.
61  *
62  * Link to the valid src->dest routes and the register values used to assign
63  * such routes for that particular device.
64  */
65 struct ni_route_tables {
66 	const struct ni_device_routes *valid_routes;
67 	const u8 *route_values;
68 };
69 
70 /*
71  * ni_assign_device_routes() - Assign the proper lookup table for NI signal
72  *			       routing to the specified NI device.
73  *
74  * Return: -ENODATA if assignment was not successful; 0 if successful.
75  */
76 int ni_assign_device_routes(const char *device_family,
77 			    const char *board_name,
78 			    const char *alt_board_name,
79 			    struct ni_route_tables *tables);
80 
81 /*
82  * ni_find_route_set() - Finds the proper route set with the specified
83  *			 destination.
84  * @destination: Destination of which to search for the route set.
85  * @valid_routes: Pointer to device routes within which to search.
86  *
87  * Return: NULL if no route_set is found with the specified @destination;
88  *	otherwise, a pointer to the route_set if found.
89  */
90 const struct ni_route_set *
91 ni_find_route_set(const int destination,
92 		  const struct ni_device_routes *valid_routes);
93 
94 /*
95  * ni_route_set_has_source() - Determines whether the given source is in
96  *			       included given route_set.
97  *
98  * Return: true if found; false otherwise.
99  */
100 bool ni_route_set_has_source(const struct ni_route_set *routes, const int src);
101 
102 /*
103  * ni_route_to_register() - Validates and converts the specified signal route
104  *			    (src-->dest) to the value used at the appropriate
105  *			    register.
106  * @src:	global-identifier for route source
107  * @dest:	global-identifier for route destination
108  * @tables:	pointer to relevant set of routing tables.
109  *
110  * Generally speaking, most routes require the first six bits and a few require
111  * 7 bits.  Special handling is given for the return value when the route is to
112  * be handled by the RTSI sub-device.  In this case, the returned register may
113  * not be sufficient to define the entire route path, but rather may only
114  * indicate the intermediate route.  For example, if the route must go through
115  * the RGOUT0 pin, the (src->RGOUT0) register value will be returned.
116  * Similarly, if the route must go through the NI_RTSI_BRD lines, the BIT(6)
117  * will be set:
118  *
119  * if route does not need RTSI_BRD lines:
120  *   bits 0:7 : register value
121  *              for a route that must go through RGOUT0 pin, this will be equal
122  *              to the (src->RGOUT0) register value.
123  * else: * route is (src->RTSI_BRD(x), RTSI_BRD(x)->TRIGGER_LINE(i)) *
124  *   bits 0:5 : zero
125  *   bits 6   : set to 1
126  *   bits 7:7 : zero
127  *
128  * Return: register value to be used for source at destination with special
129  *	cases given above; Otherwise, -1 if the specified route is not valid for
130  *	this particular device.
131  */
132 s8 ni_route_to_register(const int src, const int dest,
133 			const struct ni_route_tables *tables);
134 
135 static inline bool ni_rtsi_route_requires_mux(s8 value)
136 {
137 	return value & BIT(6);
138 }
139 
140 /*
141  * ni_lookup_route_register() - Look up a register value for a particular route
142  *				without checking whether the route is valid for
143  *				the particular device.
144  * @src:	global-identifier for route source
145  * @dest:	global-identifier for route destination
146  * @tables:	pointer to relevant set of routing tables.
147  *
148  * Return: -EINVAL if the specified route is not valid for this device family.
149  */
150 s8 ni_lookup_route_register(int src, int dest,
151 			    const struct ni_route_tables *tables);
152 
153 /**
154  * route_is_valid() - Determines whether the specified signal route (src-->dest)
155  *		      is valid for the given NI comedi_device.
156  * @src:	global-identifier for route source
157  * @dest:	global-identifier for route destination
158  * @tables:	pointer to relevant set of routing tables.
159  *
160  * Return: True if the route is valid, otherwise false.
161  */
162 static inline bool route_is_valid(const int src, const int dest,
163 				  const struct ni_route_tables *tables)
164 {
165 	return ni_route_to_register(src, dest, tables) >= 0;
166 }
167 
168 /*
169  * ni_is_cmd_dest() - Determine whether the given destination is only
170  *		      configurable via a comedi_cmd struct.
171  * @dest: Destination to test.
172  */
173 bool ni_is_cmd_dest(int dest);
174 
175 static inline bool channel_is_pfi(int channel)
176 {
177 	return NI_PFI(0) <= channel && channel <= NI_PFI(-1);
178 }
179 
180 static inline bool channel_is_rtsi(int channel)
181 {
182 	return TRIGGER_LINE(0) <= channel && channel <= TRIGGER_LINE(-1);
183 }
184 
185 static inline bool channel_is_ctr(int channel)
186 {
187 	return channel >= NI_COUNTER_NAMES_BASE &&
188 	       channel <= NI_COUNTER_NAMES_MAX;
189 }
190 
191 /*
192  * ni_count_valid_routes() - Count the number of valid routes.
193  * @tables: Routing tables for which to count all valid routes.
194  */
195 unsigned int ni_count_valid_routes(const struct ni_route_tables *tables);
196 
197 /*
198  * ni_get_valid_routes() - Implements INSN_DEVICE_CONFIG_GET_ROUTES.
199  * @tables:	pointer to relevant set of routing tables.
200  * @n_pairs:	Number of pairs for which memory is allocated by the user.  If
201  *		the user specifies '0', only the number of available pairs is
202  *		returned.
203  * @pair_data:	Pointer to memory allocated to return pairs back to user.  Each
204  *		even, odd indexed member of this array will hold source,
205  *		destination of a route pair respectively.
206  *
207  * Return: the number of valid routes if n_pairs == 0; otherwise, the number of
208  *	valid routes copied.
209  */
210 unsigned int ni_get_valid_routes(const struct ni_route_tables *tables,
211 				 unsigned int n_pairs,
212 				 unsigned int *pair_data);
213 
214 /*
215  * ni_sort_device_routes() - Sort the list of valid device signal routes in
216  *			     preparation for use.
217  * @valid_routes:	pointer to ni_device_routes struct to sort.
218  */
219 void ni_sort_device_routes(struct ni_device_routes *valid_routes);
220 
221 /*
222  * ni_find_route_source() - Finds the signal source corresponding to a signal
223  *			    route (src-->dest) of the specified routing register
224  *			    value and the specified route destination on the
225  *			    specified device.
226  *
227  * Note that this function does _not_ validate the source based on device
228  * routes.
229  *
230  * Return: The NI signal value (e.g. NI_PFI(0) or PXI_Clk10) if found.
231  *	If the source was not found (i.e. the register value is not
232  *	valid for any routes to the destination), -EINVAL is returned.
233  */
234 int ni_find_route_source(const u8 src_sel_reg_value, const int dest,
235 			 const struct ni_route_tables *tables);
236 
237 /**
238  * route_register_is_valid() - Determines whether the register value for the
239  *			       specified route destination on the specified
240  *			       device is valid.
241  */
242 static inline bool route_register_is_valid(const u8 src_sel_reg_value,
243 					   const int dest,
244 					   const struct ni_route_tables *tables)
245 {
246 	return ni_find_route_source(src_sel_reg_value, dest, tables) >= 0;
247 }
248 
249 /**
250  * ni_get_reg_value_roffs() - Determines the proper register value for a
251  *			      particular valid NI signal/terminal route.
252  * @src:	Either a direct register value or one of NI_* signal names.
253  * @dest:	global-identifier for route destination
254  * @tables:	pointer to relevant set of routing tables.
255  * @direct_reg_offset:
256  *		Compatibility compensation argument.  This argument allows us to
257  *		arbitrarily apply an offset to src if src is a direct register
258  *		value reference.  This is necessary to be compatible with
259  *		definitions of register values as previously exported directly
260  *		to user space.
261  *
262  * Return: the register value (>0) to be used at the destination if the src is
263  *	valid for the given destination; -1 otherwise.
264  */
265 static inline s8 ni_get_reg_value_roffs(int src, const int dest,
266 					const struct ni_route_tables *tables,
267 					const int direct_reg_offset)
268 {
269 	if (src < NI_NAMES_BASE) {
270 		src += direct_reg_offset;
271 		/*
272 		 * In this case, the src is expected to actually be a register
273 		 * value.
274 		 */
275 		if (route_register_is_valid(src, dest, tables))
276 			return src;
277 		return -1;
278 	}
279 
280 	/*
281 	 * Otherwise, the src is expected to be one of the abstracted NI
282 	 * signal/terminal names.
283 	 */
284 	return ni_route_to_register(src, dest, tables);
285 }
286 
287 static inline int ni_get_reg_value(const int src, const int dest,
288 				   const struct ni_route_tables *tables)
289 {
290 	return ni_get_reg_value_roffs(src, dest, tables, 0);
291 }
292 
293 /**
294  * ni_check_trigger_arg_roffs() - Checks the trigger argument (*_arg) of an NI
295  *				  device to ensure that the *_arg value
296  *				  corresponds to _either_ a valid register value
297  *				  to define a trigger source, _or_ a valid NI
298  *				  signal/terminal name that has a valid route to
299  *				  the destination on the particular device.
300  * @src:	Either a direct register value or one of NI_* signal names.
301  * @dest:	global-identifier for route destination
302  * @tables:	pointer to relevant set of routing tables.
303  * @direct_reg_offset:
304  *		Compatibility compensation argument.  This argument allows us to
305  *		arbitrarily apply an offset to src if src is a direct register
306  *		value reference.  This is necessary to be compatible with
307  *		definitions of register values as previously exported directly
308  *		to user space.
309  *
310  * Return: 0 if the src (either register value or NI signal/terminal name) is
311  *	valid for the destination; -EINVAL otherwise.
312  */
313 static inline
314 int ni_check_trigger_arg_roffs(int src, const int dest,
315 			       const struct ni_route_tables *tables,
316 			       const int direct_reg_offset)
317 {
318 	if (ni_get_reg_value_roffs(src, dest, tables, direct_reg_offset) < 0)
319 		return -EINVAL;
320 	return 0;
321 }
322 
323 static inline int ni_check_trigger_arg(const int src, const int dest,
324 				       const struct ni_route_tables *tables)
325 {
326 	return ni_check_trigger_arg_roffs(src, dest, tables, 0);
327 }
328 
329 #endif /* _COMEDI_DRIVERS_NI_ROUTES_H */
330