xref: /linux/drivers/counter/104-quad-8.c (revision d2912cb15bdda8ba4a5dd73396ad62641af2f520)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Counter driver for the ACCES 104-QUAD-8
4  * Copyright (C) 2016 William Breathitt Gray
5  *
6  * This driver supports the ACCES 104-QUAD-8 and ACCES 104-QUAD-4.
7  */
8 #include <linux/bitops.h>
9 #include <linux/counter.h>
10 #include <linux/device.h>
11 #include <linux/errno.h>
12 #include <linux/iio/iio.h>
13 #include <linux/iio/types.h>
14 #include <linux/io.h>
15 #include <linux/ioport.h>
16 #include <linux/isa.h>
17 #include <linux/kernel.h>
18 #include <linux/module.h>
19 #include <linux/moduleparam.h>
20 #include <linux/types.h>
21 
22 #define QUAD8_EXTENT 32
23 
24 static unsigned int base[max_num_isa_dev(QUAD8_EXTENT)];
25 static unsigned int num_quad8;
26 module_param_array(base, uint, &num_quad8, 0);
27 MODULE_PARM_DESC(base, "ACCES 104-QUAD-8 base addresses");
28 
29 #define QUAD8_NUM_COUNTERS 8
30 
31 /**
32  * struct quad8_iio - IIO device private data structure
33  * @counter:		instance of the counter_device
34  * @preset:		array of preset values
35  * @count_mode:		array of count mode configurations
36  * @quadrature_mode:	array of quadrature mode configurations
37  * @quadrature_scale:	array of quadrature mode scale configurations
38  * @ab_enable:		array of A and B inputs enable configurations
39  * @preset_enable:	array of set_to_preset_on_index attribute configurations
40  * @synchronous_mode:	array of index function synchronous mode configurations
41  * @index_polarity:	array of index function polarity configurations
42  * @base:		base port address of the IIO device
43  */
44 struct quad8_iio {
45 	struct counter_device counter;
46 	unsigned int preset[QUAD8_NUM_COUNTERS];
47 	unsigned int count_mode[QUAD8_NUM_COUNTERS];
48 	unsigned int quadrature_mode[QUAD8_NUM_COUNTERS];
49 	unsigned int quadrature_scale[QUAD8_NUM_COUNTERS];
50 	unsigned int ab_enable[QUAD8_NUM_COUNTERS];
51 	unsigned int preset_enable[QUAD8_NUM_COUNTERS];
52 	unsigned int synchronous_mode[QUAD8_NUM_COUNTERS];
53 	unsigned int index_polarity[QUAD8_NUM_COUNTERS];
54 	unsigned int base;
55 };
56 
57 #define QUAD8_REG_CHAN_OP 0x11
58 #define QUAD8_REG_INDEX_INPUT_LEVELS 0x16
59 /* Borrow Toggle flip-flop */
60 #define QUAD8_FLAG_BT BIT(0)
61 /* Carry Toggle flip-flop */
62 #define QUAD8_FLAG_CT BIT(1)
63 /* Error flag */
64 #define QUAD8_FLAG_E BIT(4)
65 /* Up/Down flag */
66 #define QUAD8_FLAG_UD BIT(5)
67 /* Reset and Load Signal Decoders */
68 #define QUAD8_CTR_RLD 0x00
69 /* Counter Mode Register */
70 #define QUAD8_CTR_CMR 0x20
71 /* Input / Output Control Register */
72 #define QUAD8_CTR_IOR 0x40
73 /* Index Control Register */
74 #define QUAD8_CTR_IDR 0x60
75 /* Reset Byte Pointer (three byte data pointer) */
76 #define QUAD8_RLD_RESET_BP 0x01
77 /* Reset Counter */
78 #define QUAD8_RLD_RESET_CNTR 0x02
79 /* Reset Borrow Toggle, Carry Toggle, Compare Toggle, and Sign flags */
80 #define QUAD8_RLD_RESET_FLAGS 0x04
81 /* Reset Error flag */
82 #define QUAD8_RLD_RESET_E 0x06
83 /* Preset Register to Counter */
84 #define QUAD8_RLD_PRESET_CNTR 0x08
85 /* Transfer Counter to Output Latch */
86 #define QUAD8_RLD_CNTR_OUT 0x10
87 #define QUAD8_CHAN_OP_ENABLE_COUNTERS 0x00
88 #define QUAD8_CHAN_OP_RESET_COUNTERS 0x01
89 #define QUAD8_CMR_QUADRATURE_X1 0x08
90 #define QUAD8_CMR_QUADRATURE_X2 0x10
91 #define QUAD8_CMR_QUADRATURE_X4 0x18
92 
93 
94 static int quad8_read_raw(struct iio_dev *indio_dev,
95 	struct iio_chan_spec const *chan, int *val, int *val2, long mask)
96 {
97 	struct quad8_iio *const priv = iio_priv(indio_dev);
98 	const int base_offset = priv->base + 2 * chan->channel;
99 	unsigned int flags;
100 	unsigned int borrow;
101 	unsigned int carry;
102 	int i;
103 
104 	switch (mask) {
105 	case IIO_CHAN_INFO_RAW:
106 		if (chan->type == IIO_INDEX) {
107 			*val = !!(inb(priv->base + QUAD8_REG_INDEX_INPUT_LEVELS)
108 				& BIT(chan->channel));
109 			return IIO_VAL_INT;
110 		}
111 
112 		flags = inb(base_offset + 1);
113 		borrow = flags & QUAD8_FLAG_BT;
114 		carry = !!(flags & QUAD8_FLAG_CT);
115 
116 		/* Borrow XOR Carry effectively doubles count range */
117 		*val = (borrow ^ carry) << 24;
118 
119 		/* Reset Byte Pointer; transfer Counter to Output Latch */
120 		outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP | QUAD8_RLD_CNTR_OUT,
121 		     base_offset + 1);
122 
123 		for (i = 0; i < 3; i++)
124 			*val |= (unsigned int)inb(base_offset) << (8 * i);
125 
126 		return IIO_VAL_INT;
127 	case IIO_CHAN_INFO_ENABLE:
128 		*val = priv->ab_enable[chan->channel];
129 		return IIO_VAL_INT;
130 	case IIO_CHAN_INFO_SCALE:
131 		*val = 1;
132 		*val2 = priv->quadrature_scale[chan->channel];
133 		return IIO_VAL_FRACTIONAL_LOG2;
134 	}
135 
136 	return -EINVAL;
137 }
138 
139 static int quad8_write_raw(struct iio_dev *indio_dev,
140 	struct iio_chan_spec const *chan, int val, int val2, long mask)
141 {
142 	struct quad8_iio *const priv = iio_priv(indio_dev);
143 	const int base_offset = priv->base + 2 * chan->channel;
144 	int i;
145 	unsigned int ior_cfg;
146 
147 	switch (mask) {
148 	case IIO_CHAN_INFO_RAW:
149 		if (chan->type == IIO_INDEX)
150 			return -EINVAL;
151 
152 		/* Only 24-bit values are supported */
153 		if ((unsigned int)val > 0xFFFFFF)
154 			return -EINVAL;
155 
156 		/* Reset Byte Pointer */
157 		outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP, base_offset + 1);
158 
159 		/* Counter can only be set via Preset Register */
160 		for (i = 0; i < 3; i++)
161 			outb(val >> (8 * i), base_offset);
162 
163 		/* Transfer Preset Register to Counter */
164 		outb(QUAD8_CTR_RLD | QUAD8_RLD_PRESET_CNTR, base_offset + 1);
165 
166 		/* Reset Byte Pointer */
167 		outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP, base_offset + 1);
168 
169 		/* Set Preset Register back to original value */
170 		val = priv->preset[chan->channel];
171 		for (i = 0; i < 3; i++)
172 			outb(val >> (8 * i), base_offset);
173 
174 		/* Reset Borrow, Carry, Compare, and Sign flags */
175 		outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_FLAGS, base_offset + 1);
176 		/* Reset Error flag */
177 		outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_E, base_offset + 1);
178 
179 		return 0;
180 	case IIO_CHAN_INFO_ENABLE:
181 		/* only boolean values accepted */
182 		if (val < 0 || val > 1)
183 			return -EINVAL;
184 
185 		priv->ab_enable[chan->channel] = val;
186 
187 		ior_cfg = val | priv->preset_enable[chan->channel] << 1;
188 
189 		/* Load I/O control configuration */
190 		outb(QUAD8_CTR_IOR | ior_cfg, base_offset + 1);
191 
192 		return 0;
193 	case IIO_CHAN_INFO_SCALE:
194 		/* Quadrature scaling only available in quadrature mode */
195 		if (!priv->quadrature_mode[chan->channel] && (val2 || val != 1))
196 			return -EINVAL;
197 
198 		/* Only three gain states (1, 0.5, 0.25) */
199 		if (val == 1 && !val2)
200 			priv->quadrature_scale[chan->channel] = 0;
201 		else if (!val)
202 			switch (val2) {
203 			case 500000:
204 				priv->quadrature_scale[chan->channel] = 1;
205 				break;
206 			case 250000:
207 				priv->quadrature_scale[chan->channel] = 2;
208 				break;
209 			default:
210 				return -EINVAL;
211 			}
212 		else
213 			return -EINVAL;
214 
215 		return 0;
216 	}
217 
218 	return -EINVAL;
219 }
220 
221 static const struct iio_info quad8_info = {
222 	.read_raw = quad8_read_raw,
223 	.write_raw = quad8_write_raw
224 };
225 
226 static ssize_t quad8_read_preset(struct iio_dev *indio_dev, uintptr_t private,
227 	const struct iio_chan_spec *chan, char *buf)
228 {
229 	const struct quad8_iio *const priv = iio_priv(indio_dev);
230 
231 	return snprintf(buf, PAGE_SIZE, "%u\n", priv->preset[chan->channel]);
232 }
233 
234 static ssize_t quad8_write_preset(struct iio_dev *indio_dev, uintptr_t private,
235 	const struct iio_chan_spec *chan, const char *buf, size_t len)
236 {
237 	struct quad8_iio *const priv = iio_priv(indio_dev);
238 	const int base_offset = priv->base + 2 * chan->channel;
239 	unsigned int preset;
240 	int ret;
241 	int i;
242 
243 	ret = kstrtouint(buf, 0, &preset);
244 	if (ret)
245 		return ret;
246 
247 	/* Only 24-bit values are supported */
248 	if (preset > 0xFFFFFF)
249 		return -EINVAL;
250 
251 	priv->preset[chan->channel] = preset;
252 
253 	/* Reset Byte Pointer */
254 	outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP, base_offset + 1);
255 
256 	/* Set Preset Register */
257 	for (i = 0; i < 3; i++)
258 		outb(preset >> (8 * i), base_offset);
259 
260 	return len;
261 }
262 
263 static ssize_t quad8_read_set_to_preset_on_index(struct iio_dev *indio_dev,
264 	uintptr_t private, const struct iio_chan_spec *chan, char *buf)
265 {
266 	const struct quad8_iio *const priv = iio_priv(indio_dev);
267 
268 	return snprintf(buf, PAGE_SIZE, "%u\n",
269 		!priv->preset_enable[chan->channel]);
270 }
271 
272 static ssize_t quad8_write_set_to_preset_on_index(struct iio_dev *indio_dev,
273 	uintptr_t private, const struct iio_chan_spec *chan, const char *buf,
274 	size_t len)
275 {
276 	struct quad8_iio *const priv = iio_priv(indio_dev);
277 	const int base_offset = priv->base + 2 * chan->channel + 1;
278 	bool preset_enable;
279 	int ret;
280 	unsigned int ior_cfg;
281 
282 	ret = kstrtobool(buf, &preset_enable);
283 	if (ret)
284 		return ret;
285 
286 	/* Preset enable is active low in Input/Output Control register */
287 	preset_enable = !preset_enable;
288 
289 	priv->preset_enable[chan->channel] = preset_enable;
290 
291 	ior_cfg = priv->ab_enable[chan->channel] |
292 		(unsigned int)preset_enable << 1;
293 
294 	/* Load I/O control configuration to Input / Output Control Register */
295 	outb(QUAD8_CTR_IOR | ior_cfg, base_offset);
296 
297 	return len;
298 }
299 
300 static const char *const quad8_noise_error_states[] = {
301 	"No excessive noise is present at the count inputs",
302 	"Excessive noise is present at the count inputs"
303 };
304 
305 static int quad8_get_noise_error(struct iio_dev *indio_dev,
306 	const struct iio_chan_spec *chan)
307 {
308 	struct quad8_iio *const priv = iio_priv(indio_dev);
309 	const int base_offset = priv->base + 2 * chan->channel + 1;
310 
311 	return !!(inb(base_offset) & QUAD8_FLAG_E);
312 }
313 
314 static const struct iio_enum quad8_noise_error_enum = {
315 	.items = quad8_noise_error_states,
316 	.num_items = ARRAY_SIZE(quad8_noise_error_states),
317 	.get = quad8_get_noise_error
318 };
319 
320 static const char *const quad8_count_direction_states[] = {
321 	"down",
322 	"up"
323 };
324 
325 static int quad8_get_count_direction(struct iio_dev *indio_dev,
326 	const struct iio_chan_spec *chan)
327 {
328 	struct quad8_iio *const priv = iio_priv(indio_dev);
329 	const int base_offset = priv->base + 2 * chan->channel + 1;
330 
331 	return !!(inb(base_offset) & QUAD8_FLAG_UD);
332 }
333 
334 static const struct iio_enum quad8_count_direction_enum = {
335 	.items = quad8_count_direction_states,
336 	.num_items = ARRAY_SIZE(quad8_count_direction_states),
337 	.get = quad8_get_count_direction
338 };
339 
340 static const char *const quad8_count_modes[] = {
341 	"normal",
342 	"range limit",
343 	"non-recycle",
344 	"modulo-n"
345 };
346 
347 static int quad8_set_count_mode(struct iio_dev *indio_dev,
348 	const struct iio_chan_spec *chan, unsigned int cnt_mode)
349 {
350 	struct quad8_iio *const priv = iio_priv(indio_dev);
351 	unsigned int mode_cfg = cnt_mode << 1;
352 	const int base_offset = priv->base + 2 * chan->channel + 1;
353 
354 	priv->count_mode[chan->channel] = cnt_mode;
355 
356 	/* Add quadrature mode configuration */
357 	if (priv->quadrature_mode[chan->channel])
358 		mode_cfg |= (priv->quadrature_scale[chan->channel] + 1) << 3;
359 
360 	/* Load mode configuration to Counter Mode Register */
361 	outb(QUAD8_CTR_CMR | mode_cfg, base_offset);
362 
363 	return 0;
364 }
365 
366 static int quad8_get_count_mode(struct iio_dev *indio_dev,
367 	const struct iio_chan_spec *chan)
368 {
369 	const struct quad8_iio *const priv = iio_priv(indio_dev);
370 
371 	return priv->count_mode[chan->channel];
372 }
373 
374 static const struct iio_enum quad8_count_mode_enum = {
375 	.items = quad8_count_modes,
376 	.num_items = ARRAY_SIZE(quad8_count_modes),
377 	.set = quad8_set_count_mode,
378 	.get = quad8_get_count_mode
379 };
380 
381 static const char *const quad8_synchronous_modes[] = {
382 	"non-synchronous",
383 	"synchronous"
384 };
385 
386 static int quad8_set_synchronous_mode(struct iio_dev *indio_dev,
387 	const struct iio_chan_spec *chan, unsigned int synchronous_mode)
388 {
389 	struct quad8_iio *const priv = iio_priv(indio_dev);
390 	const unsigned int idr_cfg = synchronous_mode |
391 		priv->index_polarity[chan->channel] << 1;
392 	const int base_offset = priv->base + 2 * chan->channel + 1;
393 
394 	/* Index function must be non-synchronous in non-quadrature mode */
395 	if (synchronous_mode && !priv->quadrature_mode[chan->channel])
396 		return -EINVAL;
397 
398 	priv->synchronous_mode[chan->channel] = synchronous_mode;
399 
400 	/* Load Index Control configuration to Index Control Register */
401 	outb(QUAD8_CTR_IDR | idr_cfg, base_offset);
402 
403 	return 0;
404 }
405 
406 static int quad8_get_synchronous_mode(struct iio_dev *indio_dev,
407 	const struct iio_chan_spec *chan)
408 {
409 	const struct quad8_iio *const priv = iio_priv(indio_dev);
410 
411 	return priv->synchronous_mode[chan->channel];
412 }
413 
414 static const struct iio_enum quad8_synchronous_mode_enum = {
415 	.items = quad8_synchronous_modes,
416 	.num_items = ARRAY_SIZE(quad8_synchronous_modes),
417 	.set = quad8_set_synchronous_mode,
418 	.get = quad8_get_synchronous_mode
419 };
420 
421 static const char *const quad8_quadrature_modes[] = {
422 	"non-quadrature",
423 	"quadrature"
424 };
425 
426 static int quad8_set_quadrature_mode(struct iio_dev *indio_dev,
427 	const struct iio_chan_spec *chan, unsigned int quadrature_mode)
428 {
429 	struct quad8_iio *const priv = iio_priv(indio_dev);
430 	unsigned int mode_cfg = priv->count_mode[chan->channel] << 1;
431 	const int base_offset = priv->base + 2 * chan->channel + 1;
432 
433 	if (quadrature_mode)
434 		mode_cfg |= (priv->quadrature_scale[chan->channel] + 1) << 3;
435 	else {
436 		/* Quadrature scaling only available in quadrature mode */
437 		priv->quadrature_scale[chan->channel] = 0;
438 
439 		/* Synchronous function not supported in non-quadrature mode */
440 		if (priv->synchronous_mode[chan->channel])
441 			quad8_set_synchronous_mode(indio_dev, chan, 0);
442 	}
443 
444 	priv->quadrature_mode[chan->channel] = quadrature_mode;
445 
446 	/* Load mode configuration to Counter Mode Register */
447 	outb(QUAD8_CTR_CMR | mode_cfg, base_offset);
448 
449 	return 0;
450 }
451 
452 static int quad8_get_quadrature_mode(struct iio_dev *indio_dev,
453 	const struct iio_chan_spec *chan)
454 {
455 	const struct quad8_iio *const priv = iio_priv(indio_dev);
456 
457 	return priv->quadrature_mode[chan->channel];
458 }
459 
460 static const struct iio_enum quad8_quadrature_mode_enum = {
461 	.items = quad8_quadrature_modes,
462 	.num_items = ARRAY_SIZE(quad8_quadrature_modes),
463 	.set = quad8_set_quadrature_mode,
464 	.get = quad8_get_quadrature_mode
465 };
466 
467 static const char *const quad8_index_polarity_modes[] = {
468 	"negative",
469 	"positive"
470 };
471 
472 static int quad8_set_index_polarity(struct iio_dev *indio_dev,
473 	const struct iio_chan_spec *chan, unsigned int index_polarity)
474 {
475 	struct quad8_iio *const priv = iio_priv(indio_dev);
476 	const unsigned int idr_cfg = priv->synchronous_mode[chan->channel] |
477 		index_polarity << 1;
478 	const int base_offset = priv->base + 2 * chan->channel + 1;
479 
480 	priv->index_polarity[chan->channel] = index_polarity;
481 
482 	/* Load Index Control configuration to Index Control Register */
483 	outb(QUAD8_CTR_IDR | idr_cfg, base_offset);
484 
485 	return 0;
486 }
487 
488 static int quad8_get_index_polarity(struct iio_dev *indio_dev,
489 	const struct iio_chan_spec *chan)
490 {
491 	const struct quad8_iio *const priv = iio_priv(indio_dev);
492 
493 	return priv->index_polarity[chan->channel];
494 }
495 
496 static const struct iio_enum quad8_index_polarity_enum = {
497 	.items = quad8_index_polarity_modes,
498 	.num_items = ARRAY_SIZE(quad8_index_polarity_modes),
499 	.set = quad8_set_index_polarity,
500 	.get = quad8_get_index_polarity
501 };
502 
503 static const struct iio_chan_spec_ext_info quad8_count_ext_info[] = {
504 	{
505 		.name = "preset",
506 		.shared = IIO_SEPARATE,
507 		.read = quad8_read_preset,
508 		.write = quad8_write_preset
509 	},
510 	{
511 		.name = "set_to_preset_on_index",
512 		.shared = IIO_SEPARATE,
513 		.read = quad8_read_set_to_preset_on_index,
514 		.write = quad8_write_set_to_preset_on_index
515 	},
516 	IIO_ENUM("noise_error", IIO_SEPARATE, &quad8_noise_error_enum),
517 	IIO_ENUM_AVAILABLE("noise_error", &quad8_noise_error_enum),
518 	IIO_ENUM("count_direction", IIO_SEPARATE, &quad8_count_direction_enum),
519 	IIO_ENUM_AVAILABLE("count_direction", &quad8_count_direction_enum),
520 	IIO_ENUM("count_mode", IIO_SEPARATE, &quad8_count_mode_enum),
521 	IIO_ENUM_AVAILABLE("count_mode", &quad8_count_mode_enum),
522 	IIO_ENUM("quadrature_mode", IIO_SEPARATE, &quad8_quadrature_mode_enum),
523 	IIO_ENUM_AVAILABLE("quadrature_mode", &quad8_quadrature_mode_enum),
524 	{}
525 };
526 
527 static const struct iio_chan_spec_ext_info quad8_index_ext_info[] = {
528 	IIO_ENUM("synchronous_mode", IIO_SEPARATE,
529 		&quad8_synchronous_mode_enum),
530 	IIO_ENUM_AVAILABLE("synchronous_mode", &quad8_synchronous_mode_enum),
531 	IIO_ENUM("index_polarity", IIO_SEPARATE, &quad8_index_polarity_enum),
532 	IIO_ENUM_AVAILABLE("index_polarity", &quad8_index_polarity_enum),
533 	{}
534 };
535 
536 #define QUAD8_COUNT_CHAN(_chan) {					\
537 	.type = IIO_COUNT,						\
538 	.channel = (_chan),						\
539 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |			\
540 		BIT(IIO_CHAN_INFO_ENABLE) | BIT(IIO_CHAN_INFO_SCALE),	\
541 	.ext_info = quad8_count_ext_info,				\
542 	.indexed = 1							\
543 }
544 
545 #define QUAD8_INDEX_CHAN(_chan) {			\
546 	.type = IIO_INDEX,				\
547 	.channel = (_chan),				\
548 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),	\
549 	.ext_info = quad8_index_ext_info,		\
550 	.indexed = 1					\
551 }
552 
553 static const struct iio_chan_spec quad8_channels[] = {
554 	QUAD8_COUNT_CHAN(0), QUAD8_INDEX_CHAN(0),
555 	QUAD8_COUNT_CHAN(1), QUAD8_INDEX_CHAN(1),
556 	QUAD8_COUNT_CHAN(2), QUAD8_INDEX_CHAN(2),
557 	QUAD8_COUNT_CHAN(3), QUAD8_INDEX_CHAN(3),
558 	QUAD8_COUNT_CHAN(4), QUAD8_INDEX_CHAN(4),
559 	QUAD8_COUNT_CHAN(5), QUAD8_INDEX_CHAN(5),
560 	QUAD8_COUNT_CHAN(6), QUAD8_INDEX_CHAN(6),
561 	QUAD8_COUNT_CHAN(7), QUAD8_INDEX_CHAN(7)
562 };
563 
564 static int quad8_signal_read(struct counter_device *counter,
565 	struct counter_signal *signal, struct counter_signal_read_value *val)
566 {
567 	const struct quad8_iio *const priv = counter->priv;
568 	unsigned int state;
569 	enum counter_signal_level level;
570 
571 	/* Only Index signal levels can be read */
572 	if (signal->id < 16)
573 		return -EINVAL;
574 
575 	state = inb(priv->base + QUAD8_REG_INDEX_INPUT_LEVELS)
576 		& BIT(signal->id - 16);
577 
578 	level = (state) ? COUNTER_SIGNAL_LEVEL_HIGH : COUNTER_SIGNAL_LEVEL_LOW;
579 
580 	counter_signal_read_value_set(val, COUNTER_SIGNAL_LEVEL, &level);
581 
582 	return 0;
583 }
584 
585 static int quad8_count_read(struct counter_device *counter,
586 	struct counter_count *count, struct counter_count_read_value *val)
587 {
588 	const struct quad8_iio *const priv = counter->priv;
589 	const int base_offset = priv->base + 2 * count->id;
590 	unsigned int flags;
591 	unsigned int borrow;
592 	unsigned int carry;
593 	unsigned long position;
594 	int i;
595 
596 	flags = inb(base_offset + 1);
597 	borrow = flags & QUAD8_FLAG_BT;
598 	carry = !!(flags & QUAD8_FLAG_CT);
599 
600 	/* Borrow XOR Carry effectively doubles count range */
601 	position = (unsigned long)(borrow ^ carry) << 24;
602 
603 	/* Reset Byte Pointer; transfer Counter to Output Latch */
604 	outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP | QUAD8_RLD_CNTR_OUT,
605 	     base_offset + 1);
606 
607 	for (i = 0; i < 3; i++)
608 		position |= (unsigned long)inb(base_offset) << (8 * i);
609 
610 	counter_count_read_value_set(val, COUNTER_COUNT_POSITION, &position);
611 
612 	return 0;
613 }
614 
615 static int quad8_count_write(struct counter_device *counter,
616 	struct counter_count *count, struct counter_count_write_value *val)
617 {
618 	const struct quad8_iio *const priv = counter->priv;
619 	const int base_offset = priv->base + 2 * count->id;
620 	int err;
621 	unsigned long position;
622 	int i;
623 
624 	err = counter_count_write_value_get(&position, COUNTER_COUNT_POSITION,
625 					    val);
626 	if (err)
627 		return err;
628 
629 	/* Only 24-bit values are supported */
630 	if (position > 0xFFFFFF)
631 		return -EINVAL;
632 
633 	/* Reset Byte Pointer */
634 	outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP, base_offset + 1);
635 
636 	/* Counter can only be set via Preset Register */
637 	for (i = 0; i < 3; i++)
638 		outb(position >> (8 * i), base_offset);
639 
640 	/* Transfer Preset Register to Counter */
641 	outb(QUAD8_CTR_RLD | QUAD8_RLD_PRESET_CNTR, base_offset + 1);
642 
643 	/* Reset Byte Pointer */
644 	outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP, base_offset + 1);
645 
646 	/* Set Preset Register back to original value */
647 	position = priv->preset[count->id];
648 	for (i = 0; i < 3; i++)
649 		outb(position >> (8 * i), base_offset);
650 
651 	/* Reset Borrow, Carry, Compare, and Sign flags */
652 	outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_FLAGS, base_offset + 1);
653 	/* Reset Error flag */
654 	outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_E, base_offset + 1);
655 
656 	return 0;
657 }
658 
659 enum quad8_count_function {
660 	QUAD8_COUNT_FUNCTION_PULSE_DIRECTION = 0,
661 	QUAD8_COUNT_FUNCTION_QUADRATURE_X1,
662 	QUAD8_COUNT_FUNCTION_QUADRATURE_X2,
663 	QUAD8_COUNT_FUNCTION_QUADRATURE_X4
664 };
665 
666 static enum counter_count_function quad8_count_functions_list[] = {
667 	[QUAD8_COUNT_FUNCTION_PULSE_DIRECTION] = COUNTER_COUNT_FUNCTION_PULSE_DIRECTION,
668 	[QUAD8_COUNT_FUNCTION_QUADRATURE_X1] = COUNTER_COUNT_FUNCTION_QUADRATURE_X1_A,
669 	[QUAD8_COUNT_FUNCTION_QUADRATURE_X2] = COUNTER_COUNT_FUNCTION_QUADRATURE_X2_A,
670 	[QUAD8_COUNT_FUNCTION_QUADRATURE_X4] = COUNTER_COUNT_FUNCTION_QUADRATURE_X4
671 };
672 
673 static int quad8_function_get(struct counter_device *counter,
674 	struct counter_count *count, size_t *function)
675 {
676 	const struct quad8_iio *const priv = counter->priv;
677 	const int id = count->id;
678 	const unsigned int quadrature_mode = priv->quadrature_mode[id];
679 	const unsigned int scale = priv->quadrature_scale[id];
680 
681 	if (quadrature_mode)
682 		switch (scale) {
683 		case 0:
684 			*function = QUAD8_COUNT_FUNCTION_QUADRATURE_X1;
685 			break;
686 		case 1:
687 			*function = QUAD8_COUNT_FUNCTION_QUADRATURE_X2;
688 			break;
689 		case 2:
690 			*function = QUAD8_COUNT_FUNCTION_QUADRATURE_X4;
691 			break;
692 		}
693 	else
694 		*function = QUAD8_COUNT_FUNCTION_PULSE_DIRECTION;
695 
696 	return 0;
697 }
698 
699 static int quad8_function_set(struct counter_device *counter,
700 	struct counter_count *count, size_t function)
701 {
702 	struct quad8_iio *const priv = counter->priv;
703 	const int id = count->id;
704 	unsigned int *const quadrature_mode = priv->quadrature_mode + id;
705 	unsigned int *const scale = priv->quadrature_scale + id;
706 	unsigned int mode_cfg = priv->count_mode[id] << 1;
707 	unsigned int *const synchronous_mode = priv->synchronous_mode + id;
708 	const unsigned int idr_cfg = priv->index_polarity[id] << 1;
709 	const int base_offset = priv->base + 2 * id + 1;
710 
711 	if (function == QUAD8_COUNT_FUNCTION_PULSE_DIRECTION) {
712 		*quadrature_mode = 0;
713 
714 		/* Quadrature scaling only available in quadrature mode */
715 		*scale = 0;
716 
717 		/* Synchronous function not supported in non-quadrature mode */
718 		if (*synchronous_mode) {
719 			*synchronous_mode = 0;
720 			/* Disable synchronous function mode */
721 			outb(QUAD8_CTR_IDR | idr_cfg, base_offset);
722 		}
723 	} else {
724 		*quadrature_mode = 1;
725 
726 		switch (function) {
727 		case QUAD8_COUNT_FUNCTION_QUADRATURE_X1:
728 			*scale = 0;
729 			mode_cfg |= QUAD8_CMR_QUADRATURE_X1;
730 			break;
731 		case QUAD8_COUNT_FUNCTION_QUADRATURE_X2:
732 			*scale = 1;
733 			mode_cfg |= QUAD8_CMR_QUADRATURE_X2;
734 			break;
735 		case QUAD8_COUNT_FUNCTION_QUADRATURE_X4:
736 			*scale = 2;
737 			mode_cfg |= QUAD8_CMR_QUADRATURE_X4;
738 			break;
739 		}
740 	}
741 
742 	/* Load mode configuration to Counter Mode Register */
743 	outb(QUAD8_CTR_CMR | mode_cfg, base_offset);
744 
745 	return 0;
746 }
747 
748 static void quad8_direction_get(struct counter_device *counter,
749 	struct counter_count *count, enum counter_count_direction *direction)
750 {
751 	const struct quad8_iio *const priv = counter->priv;
752 	unsigned int ud_flag;
753 	const unsigned int flag_addr = priv->base + 2 * count->id + 1;
754 
755 	/* U/D flag: nonzero = up, zero = down */
756 	ud_flag = inb(flag_addr) & QUAD8_FLAG_UD;
757 
758 	*direction = (ud_flag) ? COUNTER_COUNT_DIRECTION_FORWARD :
759 		COUNTER_COUNT_DIRECTION_BACKWARD;
760 }
761 
762 enum quad8_synapse_action {
763 	QUAD8_SYNAPSE_ACTION_NONE = 0,
764 	QUAD8_SYNAPSE_ACTION_RISING_EDGE,
765 	QUAD8_SYNAPSE_ACTION_FALLING_EDGE,
766 	QUAD8_SYNAPSE_ACTION_BOTH_EDGES
767 };
768 
769 static enum counter_synapse_action quad8_index_actions_list[] = {
770 	[QUAD8_SYNAPSE_ACTION_NONE] = COUNTER_SYNAPSE_ACTION_NONE,
771 	[QUAD8_SYNAPSE_ACTION_RISING_EDGE] = COUNTER_SYNAPSE_ACTION_RISING_EDGE
772 };
773 
774 static enum counter_synapse_action quad8_synapse_actions_list[] = {
775 	[QUAD8_SYNAPSE_ACTION_NONE] = COUNTER_SYNAPSE_ACTION_NONE,
776 	[QUAD8_SYNAPSE_ACTION_RISING_EDGE] = COUNTER_SYNAPSE_ACTION_RISING_EDGE,
777 	[QUAD8_SYNAPSE_ACTION_FALLING_EDGE] = COUNTER_SYNAPSE_ACTION_FALLING_EDGE,
778 	[QUAD8_SYNAPSE_ACTION_BOTH_EDGES] = COUNTER_SYNAPSE_ACTION_BOTH_EDGES
779 };
780 
781 static int quad8_action_get(struct counter_device *counter,
782 	struct counter_count *count, struct counter_synapse *synapse,
783 	size_t *action)
784 {
785 	struct quad8_iio *const priv = counter->priv;
786 	int err;
787 	size_t function = 0;
788 	const size_t signal_a_id = count->synapses[0].signal->id;
789 	enum counter_count_direction direction;
790 
791 	/* Handle Index signals */
792 	if (synapse->signal->id >= 16) {
793 		if (priv->preset_enable[count->id])
794 			*action = QUAD8_SYNAPSE_ACTION_RISING_EDGE;
795 		else
796 			*action = QUAD8_SYNAPSE_ACTION_NONE;
797 
798 		return 0;
799 	}
800 
801 	err = quad8_function_get(counter, count, &function);
802 	if (err)
803 		return err;
804 
805 	/* Default action mode */
806 	*action = QUAD8_SYNAPSE_ACTION_NONE;
807 
808 	/* Determine action mode based on current count function mode */
809 	switch (function) {
810 	case QUAD8_COUNT_FUNCTION_PULSE_DIRECTION:
811 		if (synapse->signal->id == signal_a_id)
812 			*action = QUAD8_SYNAPSE_ACTION_RISING_EDGE;
813 		break;
814 	case QUAD8_COUNT_FUNCTION_QUADRATURE_X1:
815 		if (synapse->signal->id == signal_a_id) {
816 			quad8_direction_get(counter, count, &direction);
817 
818 			if (direction == COUNTER_COUNT_DIRECTION_FORWARD)
819 				*action = QUAD8_SYNAPSE_ACTION_RISING_EDGE;
820 			else
821 				*action = QUAD8_SYNAPSE_ACTION_FALLING_EDGE;
822 		}
823 		break;
824 	case QUAD8_COUNT_FUNCTION_QUADRATURE_X2:
825 		if (synapse->signal->id == signal_a_id)
826 			*action = QUAD8_SYNAPSE_ACTION_BOTH_EDGES;
827 		break;
828 	case QUAD8_COUNT_FUNCTION_QUADRATURE_X4:
829 		*action = QUAD8_SYNAPSE_ACTION_BOTH_EDGES;
830 		break;
831 	}
832 
833 	return 0;
834 }
835 
836 const struct counter_ops quad8_ops = {
837 	.signal_read = quad8_signal_read,
838 	.count_read = quad8_count_read,
839 	.count_write = quad8_count_write,
840 	.function_get = quad8_function_get,
841 	.function_set = quad8_function_set,
842 	.action_get = quad8_action_get
843 };
844 
845 static int quad8_index_polarity_get(struct counter_device *counter,
846 	struct counter_signal *signal, size_t *index_polarity)
847 {
848 	const struct quad8_iio *const priv = counter->priv;
849 	const size_t channel_id = signal->id - 16;
850 
851 	*index_polarity = priv->index_polarity[channel_id];
852 
853 	return 0;
854 }
855 
856 static int quad8_index_polarity_set(struct counter_device *counter,
857 	struct counter_signal *signal, size_t index_polarity)
858 {
859 	struct quad8_iio *const priv = counter->priv;
860 	const size_t channel_id = signal->id - 16;
861 	const unsigned int idr_cfg = priv->synchronous_mode[channel_id] |
862 		index_polarity << 1;
863 	const int base_offset = priv->base + 2 * channel_id + 1;
864 
865 	priv->index_polarity[channel_id] = index_polarity;
866 
867 	/* Load Index Control configuration to Index Control Register */
868 	outb(QUAD8_CTR_IDR | idr_cfg, base_offset);
869 
870 	return 0;
871 }
872 
873 static struct counter_signal_enum_ext quad8_index_pol_enum = {
874 	.items = quad8_index_polarity_modes,
875 	.num_items = ARRAY_SIZE(quad8_index_polarity_modes),
876 	.get = quad8_index_polarity_get,
877 	.set = quad8_index_polarity_set
878 };
879 
880 static int quad8_synchronous_mode_get(struct counter_device *counter,
881 	struct counter_signal *signal, size_t *synchronous_mode)
882 {
883 	const struct quad8_iio *const priv = counter->priv;
884 	const size_t channel_id = signal->id - 16;
885 
886 	*synchronous_mode = priv->synchronous_mode[channel_id];
887 
888 	return 0;
889 }
890 
891 static int quad8_synchronous_mode_set(struct counter_device *counter,
892 	struct counter_signal *signal, size_t synchronous_mode)
893 {
894 	struct quad8_iio *const priv = counter->priv;
895 	const size_t channel_id = signal->id - 16;
896 	const unsigned int idr_cfg = synchronous_mode |
897 		priv->index_polarity[channel_id] << 1;
898 	const int base_offset = priv->base + 2 * channel_id + 1;
899 
900 	/* Index function must be non-synchronous in non-quadrature mode */
901 	if (synchronous_mode && !priv->quadrature_mode[channel_id])
902 		return -EINVAL;
903 
904 	priv->synchronous_mode[channel_id] = synchronous_mode;
905 
906 	/* Load Index Control configuration to Index Control Register */
907 	outb(QUAD8_CTR_IDR | idr_cfg, base_offset);
908 
909 	return 0;
910 }
911 
912 static struct counter_signal_enum_ext quad8_syn_mode_enum = {
913 	.items = quad8_synchronous_modes,
914 	.num_items = ARRAY_SIZE(quad8_synchronous_modes),
915 	.get = quad8_synchronous_mode_get,
916 	.set = quad8_synchronous_mode_set
917 };
918 
919 static ssize_t quad8_count_floor_read(struct counter_device *counter,
920 	struct counter_count *count, void *private, char *buf)
921 {
922 	/* Only a floor of 0 is supported */
923 	return sprintf(buf, "0\n");
924 }
925 
926 static int quad8_count_mode_get(struct counter_device *counter,
927 	struct counter_count *count, size_t *cnt_mode)
928 {
929 	const struct quad8_iio *const priv = counter->priv;
930 
931 	/* Map 104-QUAD-8 count mode to Generic Counter count mode */
932 	switch (priv->count_mode[count->id]) {
933 	case 0:
934 		*cnt_mode = COUNTER_COUNT_MODE_NORMAL;
935 		break;
936 	case 1:
937 		*cnt_mode = COUNTER_COUNT_MODE_RANGE_LIMIT;
938 		break;
939 	case 2:
940 		*cnt_mode = COUNTER_COUNT_MODE_NON_RECYCLE;
941 		break;
942 	case 3:
943 		*cnt_mode = COUNTER_COUNT_MODE_MODULO_N;
944 		break;
945 	}
946 
947 	return 0;
948 }
949 
950 static int quad8_count_mode_set(struct counter_device *counter,
951 	struct counter_count *count, size_t cnt_mode)
952 {
953 	struct quad8_iio *const priv = counter->priv;
954 	unsigned int mode_cfg;
955 	const int base_offset = priv->base + 2 * count->id + 1;
956 
957 	/* Map Generic Counter count mode to 104-QUAD-8 count mode */
958 	switch (cnt_mode) {
959 	case COUNTER_COUNT_MODE_NORMAL:
960 		cnt_mode = 0;
961 		break;
962 	case COUNTER_COUNT_MODE_RANGE_LIMIT:
963 		cnt_mode = 1;
964 		break;
965 	case COUNTER_COUNT_MODE_NON_RECYCLE:
966 		cnt_mode = 2;
967 		break;
968 	case COUNTER_COUNT_MODE_MODULO_N:
969 		cnt_mode = 3;
970 		break;
971 	}
972 
973 	priv->count_mode[count->id] = cnt_mode;
974 
975 	/* Set count mode configuration value */
976 	mode_cfg = cnt_mode << 1;
977 
978 	/* Add quadrature mode configuration */
979 	if (priv->quadrature_mode[count->id])
980 		mode_cfg |= (priv->quadrature_scale[count->id] + 1) << 3;
981 
982 	/* Load mode configuration to Counter Mode Register */
983 	outb(QUAD8_CTR_CMR | mode_cfg, base_offset);
984 
985 	return 0;
986 }
987 
988 static struct counter_count_enum_ext quad8_cnt_mode_enum = {
989 	.items = counter_count_mode_str,
990 	.num_items = ARRAY_SIZE(counter_count_mode_str),
991 	.get = quad8_count_mode_get,
992 	.set = quad8_count_mode_set
993 };
994 
995 static ssize_t quad8_count_direction_read(struct counter_device *counter,
996 	struct counter_count *count, void *priv, char *buf)
997 {
998 	enum counter_count_direction dir;
999 
1000 	quad8_direction_get(counter, count, &dir);
1001 
1002 	return sprintf(buf, "%s\n", counter_count_direction_str[dir]);
1003 }
1004 
1005 static ssize_t quad8_count_enable_read(struct counter_device *counter,
1006 	struct counter_count *count, void *private, char *buf)
1007 {
1008 	const struct quad8_iio *const priv = counter->priv;
1009 
1010 	return sprintf(buf, "%u\n", priv->ab_enable[count->id]);
1011 }
1012 
1013 static ssize_t quad8_count_enable_write(struct counter_device *counter,
1014 	struct counter_count *count, void *private, const char *buf, size_t len)
1015 {
1016 	struct quad8_iio *const priv = counter->priv;
1017 	const int base_offset = priv->base + 2 * count->id;
1018 	int err;
1019 	bool ab_enable;
1020 	unsigned int ior_cfg;
1021 
1022 	err = kstrtobool(buf, &ab_enable);
1023 	if (err)
1024 		return err;
1025 
1026 	priv->ab_enable[count->id] = ab_enable;
1027 
1028 	ior_cfg = ab_enable | priv->preset_enable[count->id] << 1;
1029 
1030 	/* Load I/O control configuration */
1031 	outb(QUAD8_CTR_IOR | ior_cfg, base_offset + 1);
1032 
1033 	return len;
1034 }
1035 
1036 static int quad8_error_noise_get(struct counter_device *counter,
1037 	struct counter_count *count, size_t *noise_error)
1038 {
1039 	const struct quad8_iio *const priv = counter->priv;
1040 	const int base_offset = priv->base + 2 * count->id + 1;
1041 
1042 	*noise_error = !!(inb(base_offset) & QUAD8_FLAG_E);
1043 
1044 	return 0;
1045 }
1046 
1047 static struct counter_count_enum_ext quad8_error_noise_enum = {
1048 	.items = quad8_noise_error_states,
1049 	.num_items = ARRAY_SIZE(quad8_noise_error_states),
1050 	.get = quad8_error_noise_get
1051 };
1052 
1053 static ssize_t quad8_count_preset_read(struct counter_device *counter,
1054 	struct counter_count *count, void *private, char *buf)
1055 {
1056 	const struct quad8_iio *const priv = counter->priv;
1057 
1058 	return sprintf(buf, "%u\n", priv->preset[count->id]);
1059 }
1060 
1061 static ssize_t quad8_count_preset_write(struct counter_device *counter,
1062 	struct counter_count *count, void *private, const char *buf, size_t len)
1063 {
1064 	struct quad8_iio *const priv = counter->priv;
1065 	const int base_offset = priv->base + 2 * count->id;
1066 	unsigned int preset;
1067 	int ret;
1068 	int i;
1069 
1070 	ret = kstrtouint(buf, 0, &preset);
1071 	if (ret)
1072 		return ret;
1073 
1074 	/* Only 24-bit values are supported */
1075 	if (preset > 0xFFFFFF)
1076 		return -EINVAL;
1077 
1078 	priv->preset[count->id] = preset;
1079 
1080 	/* Reset Byte Pointer */
1081 	outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP, base_offset + 1);
1082 
1083 	/* Set Preset Register */
1084 	for (i = 0; i < 3; i++)
1085 		outb(preset >> (8 * i), base_offset);
1086 
1087 	return len;
1088 }
1089 
1090 static ssize_t quad8_count_ceiling_read(struct counter_device *counter,
1091 	struct counter_count *count, void *private, char *buf)
1092 {
1093 	const struct quad8_iio *const priv = counter->priv;
1094 
1095 	/* Range Limit and Modulo-N count modes use preset value as ceiling */
1096 	switch (priv->count_mode[count->id]) {
1097 	case 1:
1098 	case 3:
1099 		return quad8_count_preset_read(counter, count, private, buf);
1100 	}
1101 
1102 	/* By default 0x1FFFFFF (25 bits unsigned) is maximum count */
1103 	return sprintf(buf, "33554431\n");
1104 }
1105 
1106 static ssize_t quad8_count_ceiling_write(struct counter_device *counter,
1107 	struct counter_count *count, void *private, const char *buf, size_t len)
1108 {
1109 	struct quad8_iio *const priv = counter->priv;
1110 
1111 	/* Range Limit and Modulo-N count modes use preset value as ceiling */
1112 	switch (priv->count_mode[count->id]) {
1113 	case 1:
1114 	case 3:
1115 		return quad8_count_preset_write(counter, count, private, buf,
1116 						len);
1117 	}
1118 
1119 	return len;
1120 }
1121 
1122 static ssize_t quad8_count_preset_enable_read(struct counter_device *counter,
1123 	struct counter_count *count, void *private, char *buf)
1124 {
1125 	const struct quad8_iio *const priv = counter->priv;
1126 
1127 	return sprintf(buf, "%u\n", !priv->preset_enable[count->id]);
1128 }
1129 
1130 static ssize_t quad8_count_preset_enable_write(struct counter_device *counter,
1131 	struct counter_count *count, void *private, const char *buf, size_t len)
1132 {
1133 	struct quad8_iio *const priv = counter->priv;
1134 	const int base_offset = priv->base + 2 * count->id + 1;
1135 	bool preset_enable;
1136 	int ret;
1137 	unsigned int ior_cfg;
1138 
1139 	ret = kstrtobool(buf, &preset_enable);
1140 	if (ret)
1141 		return ret;
1142 
1143 	/* Preset enable is active low in Input/Output Control register */
1144 	preset_enable = !preset_enable;
1145 
1146 	priv->preset_enable[count->id] = preset_enable;
1147 
1148 	ior_cfg = priv->ab_enable[count->id] | (unsigned int)preset_enable << 1;
1149 
1150 	/* Load I/O control configuration to Input / Output Control Register */
1151 	outb(QUAD8_CTR_IOR | ior_cfg, base_offset);
1152 
1153 	return len;
1154 }
1155 
1156 static const struct counter_signal_ext quad8_index_ext[] = {
1157 	COUNTER_SIGNAL_ENUM("index_polarity", &quad8_index_pol_enum),
1158 	COUNTER_SIGNAL_ENUM_AVAILABLE("index_polarity",	&quad8_index_pol_enum),
1159 	COUNTER_SIGNAL_ENUM("synchronous_mode", &quad8_syn_mode_enum),
1160 	COUNTER_SIGNAL_ENUM_AVAILABLE("synchronous_mode", &quad8_syn_mode_enum)
1161 };
1162 
1163 #define	QUAD8_QUAD_SIGNAL(_id, _name) {	\
1164 	.id = (_id),			\
1165 	.name = (_name)			\
1166 }
1167 
1168 #define	QUAD8_INDEX_SIGNAL(_id, _name) {	\
1169 	.id = (_id),				\
1170 	.name = (_name),			\
1171 	.ext = quad8_index_ext,			\
1172 	.num_ext = ARRAY_SIZE(quad8_index_ext)	\
1173 }
1174 
1175 static struct counter_signal quad8_signals[] = {
1176 	QUAD8_QUAD_SIGNAL(0, "Channel 1 Quadrature A"),
1177 	QUAD8_QUAD_SIGNAL(1, "Channel 1 Quadrature B"),
1178 	QUAD8_QUAD_SIGNAL(2, "Channel 2 Quadrature A"),
1179 	QUAD8_QUAD_SIGNAL(3, "Channel 2 Quadrature B"),
1180 	QUAD8_QUAD_SIGNAL(4, "Channel 3 Quadrature A"),
1181 	QUAD8_QUAD_SIGNAL(5, "Channel 3 Quadrature B"),
1182 	QUAD8_QUAD_SIGNAL(6, "Channel 4 Quadrature A"),
1183 	QUAD8_QUAD_SIGNAL(7, "Channel 4 Quadrature B"),
1184 	QUAD8_QUAD_SIGNAL(8, "Channel 5 Quadrature A"),
1185 	QUAD8_QUAD_SIGNAL(9, "Channel 5 Quadrature B"),
1186 	QUAD8_QUAD_SIGNAL(10, "Channel 6 Quadrature A"),
1187 	QUAD8_QUAD_SIGNAL(11, "Channel 6 Quadrature B"),
1188 	QUAD8_QUAD_SIGNAL(12, "Channel 7 Quadrature A"),
1189 	QUAD8_QUAD_SIGNAL(13, "Channel 7 Quadrature B"),
1190 	QUAD8_QUAD_SIGNAL(14, "Channel 8 Quadrature A"),
1191 	QUAD8_QUAD_SIGNAL(15, "Channel 8 Quadrature B"),
1192 	QUAD8_INDEX_SIGNAL(16, "Channel 1 Index"),
1193 	QUAD8_INDEX_SIGNAL(17, "Channel 2 Index"),
1194 	QUAD8_INDEX_SIGNAL(18, "Channel 3 Index"),
1195 	QUAD8_INDEX_SIGNAL(19, "Channel 4 Index"),
1196 	QUAD8_INDEX_SIGNAL(20, "Channel 5 Index"),
1197 	QUAD8_INDEX_SIGNAL(21, "Channel 6 Index"),
1198 	QUAD8_INDEX_SIGNAL(22, "Channel 7 Index"),
1199 	QUAD8_INDEX_SIGNAL(23, "Channel 8 Index")
1200 };
1201 
1202 #define QUAD8_COUNT_SYNAPSES(_id) {					\
1203 	{								\
1204 		.actions_list = quad8_synapse_actions_list,		\
1205 		.num_actions = ARRAY_SIZE(quad8_synapse_actions_list),	\
1206 		.signal = quad8_signals + 2 * (_id)			\
1207 	},								\
1208 	{								\
1209 		.actions_list = quad8_synapse_actions_list,		\
1210 		.num_actions = ARRAY_SIZE(quad8_synapse_actions_list),	\
1211 		.signal = quad8_signals + 2 * (_id) + 1			\
1212 	},								\
1213 	{								\
1214 		.actions_list = quad8_index_actions_list,		\
1215 		.num_actions = ARRAY_SIZE(quad8_index_actions_list),	\
1216 		.signal = quad8_signals + 2 * (_id) + 16		\
1217 	}								\
1218 }
1219 
1220 static struct counter_synapse quad8_count_synapses[][3] = {
1221 	QUAD8_COUNT_SYNAPSES(0), QUAD8_COUNT_SYNAPSES(1),
1222 	QUAD8_COUNT_SYNAPSES(2), QUAD8_COUNT_SYNAPSES(3),
1223 	QUAD8_COUNT_SYNAPSES(4), QUAD8_COUNT_SYNAPSES(5),
1224 	QUAD8_COUNT_SYNAPSES(6), QUAD8_COUNT_SYNAPSES(7)
1225 };
1226 
1227 static const struct counter_count_ext quad8_count_ext[] = {
1228 	{
1229 		.name = "ceiling",
1230 		.read = quad8_count_ceiling_read,
1231 		.write = quad8_count_ceiling_write
1232 	},
1233 	{
1234 		.name = "floor",
1235 		.read = quad8_count_floor_read
1236 	},
1237 	COUNTER_COUNT_ENUM("count_mode", &quad8_cnt_mode_enum),
1238 	COUNTER_COUNT_ENUM_AVAILABLE("count_mode", &quad8_cnt_mode_enum),
1239 	{
1240 		.name = "direction",
1241 		.read = quad8_count_direction_read
1242 	},
1243 	{
1244 		.name = "enable",
1245 		.read = quad8_count_enable_read,
1246 		.write = quad8_count_enable_write
1247 	},
1248 	COUNTER_COUNT_ENUM("error_noise", &quad8_error_noise_enum),
1249 	COUNTER_COUNT_ENUM_AVAILABLE("error_noise", &quad8_error_noise_enum),
1250 	{
1251 		.name = "preset",
1252 		.read = quad8_count_preset_read,
1253 		.write = quad8_count_preset_write
1254 	},
1255 	{
1256 		.name = "preset_enable",
1257 		.read = quad8_count_preset_enable_read,
1258 		.write = quad8_count_preset_enable_write
1259 	}
1260 };
1261 
1262 #define QUAD8_COUNT(_id, _cntname) {					\
1263 	.id = (_id),							\
1264 	.name = (_cntname),						\
1265 	.functions_list = quad8_count_functions_list,			\
1266 	.num_functions = ARRAY_SIZE(quad8_count_functions_list),	\
1267 	.synapses = quad8_count_synapses[(_id)],			\
1268 	.num_synapses =	2,						\
1269 	.ext = quad8_count_ext,						\
1270 	.num_ext = ARRAY_SIZE(quad8_count_ext)				\
1271 }
1272 
1273 static struct counter_count quad8_counts[] = {
1274 	QUAD8_COUNT(0, "Channel 1 Count"),
1275 	QUAD8_COUNT(1, "Channel 2 Count"),
1276 	QUAD8_COUNT(2, "Channel 3 Count"),
1277 	QUAD8_COUNT(3, "Channel 4 Count"),
1278 	QUAD8_COUNT(4, "Channel 5 Count"),
1279 	QUAD8_COUNT(5, "Channel 6 Count"),
1280 	QUAD8_COUNT(6, "Channel 7 Count"),
1281 	QUAD8_COUNT(7, "Channel 8 Count")
1282 };
1283 
1284 static int quad8_probe(struct device *dev, unsigned int id)
1285 {
1286 	struct iio_dev *indio_dev;
1287 	struct quad8_iio *quad8iio;
1288 	int i, j;
1289 	unsigned int base_offset;
1290 	int err;
1291 
1292 	if (!devm_request_region(dev, base[id], QUAD8_EXTENT, dev_name(dev))) {
1293 		dev_err(dev, "Unable to lock port addresses (0x%X-0x%X)\n",
1294 			base[id], base[id] + QUAD8_EXTENT);
1295 		return -EBUSY;
1296 	}
1297 
1298 	/* Allocate IIO device; this also allocates driver data structure */
1299 	indio_dev = devm_iio_device_alloc(dev, sizeof(*quad8iio));
1300 	if (!indio_dev)
1301 		return -ENOMEM;
1302 
1303 	/* Initialize IIO device */
1304 	indio_dev->info = &quad8_info;
1305 	indio_dev->modes = INDIO_DIRECT_MODE;
1306 	indio_dev->num_channels = ARRAY_SIZE(quad8_channels);
1307 	indio_dev->channels = quad8_channels;
1308 	indio_dev->name = dev_name(dev);
1309 	indio_dev->dev.parent = dev;
1310 
1311 	/* Initialize Counter device and driver data */
1312 	quad8iio = iio_priv(indio_dev);
1313 	quad8iio->counter.name = dev_name(dev);
1314 	quad8iio->counter.parent = dev;
1315 	quad8iio->counter.ops = &quad8_ops;
1316 	quad8iio->counter.counts = quad8_counts;
1317 	quad8iio->counter.num_counts = ARRAY_SIZE(quad8_counts);
1318 	quad8iio->counter.signals = quad8_signals;
1319 	quad8iio->counter.num_signals = ARRAY_SIZE(quad8_signals);
1320 	quad8iio->counter.priv = quad8iio;
1321 	quad8iio->base = base[id];
1322 
1323 	/* Reset all counters and disable interrupt function */
1324 	outb(QUAD8_CHAN_OP_RESET_COUNTERS, base[id] + QUAD8_REG_CHAN_OP);
1325 	/* Set initial configuration for all counters */
1326 	for (i = 0; i < QUAD8_NUM_COUNTERS; i++) {
1327 		base_offset = base[id] + 2 * i;
1328 		/* Reset Byte Pointer */
1329 		outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP, base_offset + 1);
1330 		/* Reset Preset Register */
1331 		for (j = 0; j < 3; j++)
1332 			outb(0x00, base_offset);
1333 		/* Reset Borrow, Carry, Compare, and Sign flags */
1334 		outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_FLAGS, base_offset + 1);
1335 		/* Reset Error flag */
1336 		outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_E, base_offset + 1);
1337 		/* Binary encoding; Normal count; non-quadrature mode */
1338 		outb(QUAD8_CTR_CMR, base_offset + 1);
1339 		/* Disable A and B inputs; preset on index; FLG1 as Carry */
1340 		outb(QUAD8_CTR_IOR, base_offset + 1);
1341 		/* Disable index function; negative index polarity */
1342 		outb(QUAD8_CTR_IDR, base_offset + 1);
1343 	}
1344 	/* Enable all counters */
1345 	outb(QUAD8_CHAN_OP_ENABLE_COUNTERS, base[id] + QUAD8_REG_CHAN_OP);
1346 
1347 	/* Register IIO device */
1348 	err = devm_iio_device_register(dev, indio_dev);
1349 	if (err)
1350 		return err;
1351 
1352 	/* Register Counter device */
1353 	return devm_counter_register(dev, &quad8iio->counter);
1354 }
1355 
1356 static struct isa_driver quad8_driver = {
1357 	.probe = quad8_probe,
1358 	.driver = {
1359 		.name = "104-quad-8"
1360 	}
1361 };
1362 
1363 module_isa_driver(quad8_driver, num_quad8);
1364 
1365 MODULE_AUTHOR("William Breathitt Gray <vilhelm.gray@gmail.com>");
1366 MODULE_DESCRIPTION("ACCES 104-QUAD-8 IIO driver");
1367 MODULE_LICENSE("GPL v2");
1368