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
24static unsigned int base[max_num_isa_dev(QUAD8_EXTENT)];
25static unsigned int num_quad8;
26module_param_array(base, uint, &num_quad8, 0);
27MODULE_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 * @fck_prescaler:	array of filter clock prescaler configurations
35 * @preset:		array of preset values
36 * @count_mode:		array of count mode configurations
37 * @quadrature_mode:	array of quadrature mode configurations
38 * @quadrature_scale:	array of quadrature mode scale configurations
39 * @ab_enable:		array of A and B inputs enable configurations
40 * @preset_enable:	array of set_to_preset_on_index attribute configurations
41 * @synchronous_mode:	array of index function synchronous mode configurations
42 * @index_polarity:	array of index function polarity configurations
43 * @cable_fault_enable:	differential encoder cable status enable configurations
44 * @base:		base port address of the IIO device
45 */
46struct quad8_iio {
47	struct mutex lock;
48	struct counter_device counter;
49	unsigned int fck_prescaler[QUAD8_NUM_COUNTERS];
50	unsigned int preset[QUAD8_NUM_COUNTERS];
51	unsigned int count_mode[QUAD8_NUM_COUNTERS];
52	unsigned int quadrature_mode[QUAD8_NUM_COUNTERS];
53	unsigned int quadrature_scale[QUAD8_NUM_COUNTERS];
54	unsigned int ab_enable[QUAD8_NUM_COUNTERS];
55	unsigned int preset_enable[QUAD8_NUM_COUNTERS];
56	unsigned int synchronous_mode[QUAD8_NUM_COUNTERS];
57	unsigned int index_polarity[QUAD8_NUM_COUNTERS];
58	unsigned int cable_fault_enable;
59	unsigned int base;
60};
61
62#define QUAD8_REG_CHAN_OP 0x11
63#define QUAD8_REG_INDEX_INPUT_LEVELS 0x16
64#define QUAD8_DIFF_ENCODER_CABLE_STATUS 0x17
65/* Error flag */
66#define QUAD8_FLAG_E BIT(4)
67/* Up/Down flag */
68#define QUAD8_FLAG_UD BIT(5)
69/* Reset and Load Signal Decoders */
70#define QUAD8_CTR_RLD 0x00
71/* Counter Mode Register */
72#define QUAD8_CTR_CMR 0x20
73/* Input / Output Control Register */
74#define QUAD8_CTR_IOR 0x40
75/* Index Control Register */
76#define QUAD8_CTR_IDR 0x60
77/* Reset Byte Pointer (three byte data pointer) */
78#define QUAD8_RLD_RESET_BP 0x01
79/* Reset Counter */
80#define QUAD8_RLD_RESET_CNTR 0x02
81/* Reset Borrow Toggle, Carry Toggle, Compare Toggle, and Sign flags */
82#define QUAD8_RLD_RESET_FLAGS 0x04
83/* Reset Error flag */
84#define QUAD8_RLD_RESET_E 0x06
85/* Preset Register to Counter */
86#define QUAD8_RLD_PRESET_CNTR 0x08
87/* Transfer Counter to Output Latch */
88#define QUAD8_RLD_CNTR_OUT 0x10
89/* Transfer Preset Register LSB to FCK Prescaler */
90#define QUAD8_RLD_PRESET_PSC 0x18
91#define QUAD8_CHAN_OP_ENABLE_COUNTERS 0x00
92#define QUAD8_CHAN_OP_RESET_COUNTERS 0x01
93#define QUAD8_CMR_QUADRATURE_X1 0x08
94#define QUAD8_CMR_QUADRATURE_X2 0x10
95#define QUAD8_CMR_QUADRATURE_X4 0x18
96
97
98static int quad8_read_raw(struct iio_dev *indio_dev,
99	struct iio_chan_spec const *chan, int *val, int *val2, long mask)
100{
101	struct quad8_iio *const priv = iio_priv(indio_dev);
102	const int base_offset = priv->base + 2 * chan->channel;
103	int i;
104
105	switch (mask) {
106	case IIO_CHAN_INFO_RAW:
107		if (chan->type == IIO_INDEX) {
108			*val = !!(inb(priv->base + QUAD8_REG_INDEX_INPUT_LEVELS)
109				& BIT(chan->channel));
110			return IIO_VAL_INT;
111		}
112
113		*val = 0;
114
115		mutex_lock(&priv->lock);
116
117		/* Reset Byte Pointer; transfer Counter to Output Latch */
118		outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP | QUAD8_RLD_CNTR_OUT,
119		     base_offset + 1);
120
121		for (i = 0; i < 3; i++)
122			*val |= (unsigned int)inb(base_offset) << (8 * i);
123
124		mutex_unlock(&priv->lock);
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
139static 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		mutex_lock(&priv->lock);
157
158		/* Reset Byte Pointer */
159		outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP, base_offset + 1);
160
161		/* Counter can only be set via Preset Register */
162		for (i = 0; i < 3; i++)
163			outb(val >> (8 * i), base_offset);
164
165		/* Transfer Preset Register to Counter */
166		outb(QUAD8_CTR_RLD | QUAD8_RLD_PRESET_CNTR, base_offset + 1);
167
168		/* Reset Byte Pointer */
169		outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP, base_offset + 1);
170
171		/* Set Preset Register back to original value */
172		val = priv->preset[chan->channel];
173		for (i = 0; i < 3; i++)
174			outb(val >> (8 * i), base_offset);
175
176		/* Reset Borrow, Carry, Compare, and Sign flags */
177		outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_FLAGS, base_offset + 1);
178		/* Reset Error flag */
179		outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_E, base_offset + 1);
180
181		mutex_unlock(&priv->lock);
182
183		return 0;
184	case IIO_CHAN_INFO_ENABLE:
185		/* only boolean values accepted */
186		if (val < 0 || val > 1)
187			return -EINVAL;
188
189		mutex_lock(&priv->lock);
190
191		priv->ab_enable[chan->channel] = val;
192
193		ior_cfg = val | priv->preset_enable[chan->channel] << 1;
194
195		/* Load I/O control configuration */
196		outb(QUAD8_CTR_IOR | ior_cfg, base_offset + 1);
197
198		mutex_unlock(&priv->lock);
199
200		return 0;
201	case IIO_CHAN_INFO_SCALE:
202		mutex_lock(&priv->lock);
203
204		/* Quadrature scaling only available in quadrature mode */
205		if (!priv->quadrature_mode[chan->channel] &&
206				(val2 || val != 1)) {
207			mutex_unlock(&priv->lock);
208			return -EINVAL;
209		}
210
211		/* Only three gain states (1, 0.5, 0.25) */
212		if (val == 1 && !val2)
213			priv->quadrature_scale[chan->channel] = 0;
214		else if (!val)
215			switch (val2) {
216			case 500000:
217				priv->quadrature_scale[chan->channel] = 1;
218				break;
219			case 250000:
220				priv->quadrature_scale[chan->channel] = 2;
221				break;
222			default:
223				mutex_unlock(&priv->lock);
224				return -EINVAL;
225			}
226		else {
227			mutex_unlock(&priv->lock);
228			return -EINVAL;
229		}
230
231		mutex_unlock(&priv->lock);
232		return 0;
233	}
234
235	return -EINVAL;
236}
237
238static const struct iio_info quad8_info = {
239	.read_raw = quad8_read_raw,
240	.write_raw = quad8_write_raw
241};
242
243static ssize_t quad8_read_preset(struct iio_dev *indio_dev, uintptr_t private,
244	const struct iio_chan_spec *chan, char *buf)
245{
246	const struct quad8_iio *const priv = iio_priv(indio_dev);
247
248	return snprintf(buf, PAGE_SIZE, "%u\n", priv->preset[chan->channel]);
249}
250
251static ssize_t quad8_write_preset(struct iio_dev *indio_dev, uintptr_t private,
252	const struct iio_chan_spec *chan, const char *buf, size_t len)
253{
254	struct quad8_iio *const priv = iio_priv(indio_dev);
255	const int base_offset = priv->base + 2 * chan->channel;
256	unsigned int preset;
257	int ret;
258	int i;
259
260	ret = kstrtouint(buf, 0, &preset);
261	if (ret)
262		return ret;
263
264	/* Only 24-bit values are supported */
265	if (preset > 0xFFFFFF)
266		return -EINVAL;
267
268	mutex_lock(&priv->lock);
269
270	priv->preset[chan->channel] = preset;
271
272	/* Reset Byte Pointer */
273	outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP, base_offset + 1);
274
275	/* Set Preset Register */
276	for (i = 0; i < 3; i++)
277		outb(preset >> (8 * i), base_offset);
278
279	mutex_unlock(&priv->lock);
280
281	return len;
282}
283
284static ssize_t quad8_read_set_to_preset_on_index(struct iio_dev *indio_dev,
285	uintptr_t private, const struct iio_chan_spec *chan, char *buf)
286{
287	const struct quad8_iio *const priv = iio_priv(indio_dev);
288
289	return snprintf(buf, PAGE_SIZE, "%u\n",
290		!priv->preset_enable[chan->channel]);
291}
292
293static ssize_t quad8_write_set_to_preset_on_index(struct iio_dev *indio_dev,
294	uintptr_t private, const struct iio_chan_spec *chan, const char *buf,
295	size_t len)
296{
297	struct quad8_iio *const priv = iio_priv(indio_dev);
298	const int base_offset = priv->base + 2 * chan->channel + 1;
299	bool preset_enable;
300	int ret;
301	unsigned int ior_cfg;
302
303	ret = kstrtobool(buf, &preset_enable);
304	if (ret)
305		return ret;
306
307	/* Preset enable is active low in Input/Output Control register */
308	preset_enable = !preset_enable;
309
310	mutex_lock(&priv->lock);
311
312	priv->preset_enable[chan->channel] = preset_enable;
313
314	ior_cfg = priv->ab_enable[chan->channel] |
315		(unsigned int)preset_enable << 1;
316
317	/* Load I/O control configuration to Input / Output Control Register */
318	outb(QUAD8_CTR_IOR | ior_cfg, base_offset);
319
320	mutex_unlock(&priv->lock);
321
322	return len;
323}
324
325static const char *const quad8_noise_error_states[] = {
326	"No excessive noise is present at the count inputs",
327	"Excessive noise is present at the count inputs"
328};
329
330static int quad8_get_noise_error(struct iio_dev *indio_dev,
331	const struct iio_chan_spec *chan)
332{
333	struct quad8_iio *const priv = iio_priv(indio_dev);
334	const int base_offset = priv->base + 2 * chan->channel + 1;
335
336	return !!(inb(base_offset) & QUAD8_FLAG_E);
337}
338
339static const struct iio_enum quad8_noise_error_enum = {
340	.items = quad8_noise_error_states,
341	.num_items = ARRAY_SIZE(quad8_noise_error_states),
342	.get = quad8_get_noise_error
343};
344
345static const char *const quad8_count_direction_states[] = {
346	"down",
347	"up"
348};
349
350static int quad8_get_count_direction(struct iio_dev *indio_dev,
351	const struct iio_chan_spec *chan)
352{
353	struct quad8_iio *const priv = iio_priv(indio_dev);
354	const int base_offset = priv->base + 2 * chan->channel + 1;
355
356	return !!(inb(base_offset) & QUAD8_FLAG_UD);
357}
358
359static const struct iio_enum quad8_count_direction_enum = {
360	.items = quad8_count_direction_states,
361	.num_items = ARRAY_SIZE(quad8_count_direction_states),
362	.get = quad8_get_count_direction
363};
364
365static const char *const quad8_count_modes[] = {
366	"normal",
367	"range limit",
368	"non-recycle",
369	"modulo-n"
370};
371
372static int quad8_set_count_mode(struct iio_dev *indio_dev,
373	const struct iio_chan_spec *chan, unsigned int cnt_mode)
374{
375	struct quad8_iio *const priv = iio_priv(indio_dev);
376	unsigned int mode_cfg = cnt_mode << 1;
377	const int base_offset = priv->base + 2 * chan->channel + 1;
378
379	mutex_lock(&priv->lock);
380
381	priv->count_mode[chan->channel] = cnt_mode;
382
383	/* Add quadrature mode configuration */
384	if (priv->quadrature_mode[chan->channel])
385		mode_cfg |= (priv->quadrature_scale[chan->channel] + 1) << 3;
386
387	/* Load mode configuration to Counter Mode Register */
388	outb(QUAD8_CTR_CMR | mode_cfg, base_offset);
389
390	mutex_unlock(&priv->lock);
391
392	return 0;
393}
394
395static int quad8_get_count_mode(struct iio_dev *indio_dev,
396	const struct iio_chan_spec *chan)
397{
398	const struct quad8_iio *const priv = iio_priv(indio_dev);
399
400	return priv->count_mode[chan->channel];
401}
402
403static const struct iio_enum quad8_count_mode_enum = {
404	.items = quad8_count_modes,
405	.num_items = ARRAY_SIZE(quad8_count_modes),
406	.set = quad8_set_count_mode,
407	.get = quad8_get_count_mode
408};
409
410static const char *const quad8_synchronous_modes[] = {
411	"non-synchronous",
412	"synchronous"
413};
414
415static int quad8_set_synchronous_mode(struct iio_dev *indio_dev,
416	const struct iio_chan_spec *chan, unsigned int synchronous_mode)
417{
418	struct quad8_iio *const priv = iio_priv(indio_dev);
419	const int base_offset = priv->base + 2 * chan->channel + 1;
420	unsigned int idr_cfg = synchronous_mode;
421
422	mutex_lock(&priv->lock);
423
424	idr_cfg |= priv->index_polarity[chan->channel] << 1;
425
426	/* Index function must be non-synchronous in non-quadrature mode */
427	if (synchronous_mode && !priv->quadrature_mode[chan->channel]) {
428		mutex_unlock(&priv->lock);
429		return -EINVAL;
430	}
431
432	priv->synchronous_mode[chan->channel] = synchronous_mode;
433
434	/* Load Index Control configuration to Index Control Register */
435	outb(QUAD8_CTR_IDR | idr_cfg, base_offset);
436
437	mutex_unlock(&priv->lock);
438
439	return 0;
440}
441
442static int quad8_get_synchronous_mode(struct iio_dev *indio_dev,
443	const struct iio_chan_spec *chan)
444{
445	const struct quad8_iio *const priv = iio_priv(indio_dev);
446
447	return priv->synchronous_mode[chan->channel];
448}
449
450static const struct iio_enum quad8_synchronous_mode_enum = {
451	.items = quad8_synchronous_modes,
452	.num_items = ARRAY_SIZE(quad8_synchronous_modes),
453	.set = quad8_set_synchronous_mode,
454	.get = quad8_get_synchronous_mode
455};
456
457static const char *const quad8_quadrature_modes[] = {
458	"non-quadrature",
459	"quadrature"
460};
461
462static int quad8_set_quadrature_mode(struct iio_dev *indio_dev,
463	const struct iio_chan_spec *chan, unsigned int quadrature_mode)
464{
465	struct quad8_iio *const priv = iio_priv(indio_dev);
466	const int base_offset = priv->base + 2 * chan->channel + 1;
467	unsigned int mode_cfg;
468
469	mutex_lock(&priv->lock);
470
471	mode_cfg = priv->count_mode[chan->channel] << 1;
472
473	if (quadrature_mode)
474		mode_cfg |= (priv->quadrature_scale[chan->channel] + 1) << 3;
475	else {
476		/* Quadrature scaling only available in quadrature mode */
477		priv->quadrature_scale[chan->channel] = 0;
478
479		/* Synchronous function not supported in non-quadrature mode */
480		if (priv->synchronous_mode[chan->channel])
481			quad8_set_synchronous_mode(indio_dev, chan, 0);
482	}
483
484	priv->quadrature_mode[chan->channel] = quadrature_mode;
485
486	/* Load mode configuration to Counter Mode Register */
487	outb(QUAD8_CTR_CMR | mode_cfg, base_offset);
488
489	mutex_unlock(&priv->lock);
490
491	return 0;
492}
493
494static int quad8_get_quadrature_mode(struct iio_dev *indio_dev,
495	const struct iio_chan_spec *chan)
496{
497	const struct quad8_iio *const priv = iio_priv(indio_dev);
498
499	return priv->quadrature_mode[chan->channel];
500}
501
502static const struct iio_enum quad8_quadrature_mode_enum = {
503	.items = quad8_quadrature_modes,
504	.num_items = ARRAY_SIZE(quad8_quadrature_modes),
505	.set = quad8_set_quadrature_mode,
506	.get = quad8_get_quadrature_mode
507};
508
509static const char *const quad8_index_polarity_modes[] = {
510	"negative",
511	"positive"
512};
513
514static int quad8_set_index_polarity(struct iio_dev *indio_dev,
515	const struct iio_chan_spec *chan, unsigned int index_polarity)
516{
517	struct quad8_iio *const priv = iio_priv(indio_dev);
518	const int base_offset = priv->base + 2 * chan->channel + 1;
519	unsigned int idr_cfg = index_polarity << 1;
520
521	mutex_lock(&priv->lock);
522
523	idr_cfg |= priv->synchronous_mode[chan->channel];
524
525	priv->index_polarity[chan->channel] = index_polarity;
526
527	/* Load Index Control configuration to Index Control Register */
528	outb(QUAD8_CTR_IDR | idr_cfg, base_offset);
529
530	mutex_unlock(&priv->lock);
531
532	return 0;
533}
534
535static int quad8_get_index_polarity(struct iio_dev *indio_dev,
536	const struct iio_chan_spec *chan)
537{
538	const struct quad8_iio *const priv = iio_priv(indio_dev);
539
540	return priv->index_polarity[chan->channel];
541}
542
543static const struct iio_enum quad8_index_polarity_enum = {
544	.items = quad8_index_polarity_modes,
545	.num_items = ARRAY_SIZE(quad8_index_polarity_modes),
546	.set = quad8_set_index_polarity,
547	.get = quad8_get_index_polarity
548};
549
550static const struct iio_chan_spec_ext_info quad8_count_ext_info[] = {
551	{
552		.name = "preset",
553		.shared = IIO_SEPARATE,
554		.read = quad8_read_preset,
555		.write = quad8_write_preset
556	},
557	{
558		.name = "set_to_preset_on_index",
559		.shared = IIO_SEPARATE,
560		.read = quad8_read_set_to_preset_on_index,
561		.write = quad8_write_set_to_preset_on_index
562	},
563	IIO_ENUM("noise_error", IIO_SEPARATE, &quad8_noise_error_enum),
564	IIO_ENUM_AVAILABLE("noise_error", &quad8_noise_error_enum),
565	IIO_ENUM("count_direction", IIO_SEPARATE, &quad8_count_direction_enum),
566	IIO_ENUM_AVAILABLE("count_direction", &quad8_count_direction_enum),
567	IIO_ENUM("count_mode", IIO_SEPARATE, &quad8_count_mode_enum),
568	IIO_ENUM_AVAILABLE("count_mode", &quad8_count_mode_enum),
569	IIO_ENUM("quadrature_mode", IIO_SEPARATE, &quad8_quadrature_mode_enum),
570	IIO_ENUM_AVAILABLE("quadrature_mode", &quad8_quadrature_mode_enum),
571	{}
572};
573
574static const struct iio_chan_spec_ext_info quad8_index_ext_info[] = {
575	IIO_ENUM("synchronous_mode", IIO_SEPARATE,
576		&quad8_synchronous_mode_enum),
577	IIO_ENUM_AVAILABLE("synchronous_mode", &quad8_synchronous_mode_enum),
578	IIO_ENUM("index_polarity", IIO_SEPARATE, &quad8_index_polarity_enum),
579	IIO_ENUM_AVAILABLE("index_polarity", &quad8_index_polarity_enum),
580	{}
581};
582
583#define QUAD8_COUNT_CHAN(_chan) {					\
584	.type = IIO_COUNT,						\
585	.channel = (_chan),						\
586	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |			\
587		BIT(IIO_CHAN_INFO_ENABLE) | BIT(IIO_CHAN_INFO_SCALE),	\
588	.ext_info = quad8_count_ext_info,				\
589	.indexed = 1							\
590}
591
592#define QUAD8_INDEX_CHAN(_chan) {			\
593	.type = IIO_INDEX,				\
594	.channel = (_chan),				\
595	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),	\
596	.ext_info = quad8_index_ext_info,		\
597	.indexed = 1					\
598}
599
600static const struct iio_chan_spec quad8_channels[] = {
601	QUAD8_COUNT_CHAN(0), QUAD8_INDEX_CHAN(0),
602	QUAD8_COUNT_CHAN(1), QUAD8_INDEX_CHAN(1),
603	QUAD8_COUNT_CHAN(2), QUAD8_INDEX_CHAN(2),
604	QUAD8_COUNT_CHAN(3), QUAD8_INDEX_CHAN(3),
605	QUAD8_COUNT_CHAN(4), QUAD8_INDEX_CHAN(4),
606	QUAD8_COUNT_CHAN(5), QUAD8_INDEX_CHAN(5),
607	QUAD8_COUNT_CHAN(6), QUAD8_INDEX_CHAN(6),
608	QUAD8_COUNT_CHAN(7), QUAD8_INDEX_CHAN(7)
609};
610
611static int quad8_signal_read(struct counter_device *counter,
612	struct counter_signal *signal, enum counter_signal_value *val)
613{
614	const struct quad8_iio *const priv = counter->priv;
615	unsigned int state;
616
617	/* Only Index signal levels can be read */
618	if (signal->id < 16)
619		return -EINVAL;
620
621	state = inb(priv->base + QUAD8_REG_INDEX_INPUT_LEVELS)
622		& BIT(signal->id - 16);
623
624	*val = (state) ? COUNTER_SIGNAL_HIGH : COUNTER_SIGNAL_LOW;
625
626	return 0;
627}
628
629static int quad8_count_read(struct counter_device *counter,
630	struct counter_count *count, unsigned long *val)
631{
632	struct quad8_iio *const priv = counter->priv;
633	const int base_offset = priv->base + 2 * count->id;
634	int i;
635
636	*val = 0;
637
638	mutex_lock(&priv->lock);
639
640	/* Reset Byte Pointer; transfer Counter to Output Latch */
641	outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP | QUAD8_RLD_CNTR_OUT,
642	     base_offset + 1);
643
644	for (i = 0; i < 3; i++)
645		*val |= (unsigned long)inb(base_offset) << (8 * i);
646
647	mutex_unlock(&priv->lock);
648
649	return 0;
650}
651
652static int quad8_count_write(struct counter_device *counter,
653	struct counter_count *count, unsigned long val)
654{
655	struct quad8_iio *const priv = counter->priv;
656	const int base_offset = priv->base + 2 * count->id;
657	int i;
658
659	/* Only 24-bit values are supported */
660	if (val > 0xFFFFFF)
661		return -EINVAL;
662
663	mutex_lock(&priv->lock);
664
665	/* Reset Byte Pointer */
666	outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP, base_offset + 1);
667
668	/* Counter can only be set via Preset Register */
669	for (i = 0; i < 3; i++)
670		outb(val >> (8 * i), base_offset);
671
672	/* Transfer Preset Register to Counter */
673	outb(QUAD8_CTR_RLD | QUAD8_RLD_PRESET_CNTR, base_offset + 1);
674
675	/* Reset Byte Pointer */
676	outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP, base_offset + 1);
677
678	/* Set Preset Register back to original value */
679	val = priv->preset[count->id];
680	for (i = 0; i < 3; i++)
681		outb(val >> (8 * i), base_offset);
682
683	/* Reset Borrow, Carry, Compare, and Sign flags */
684	outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_FLAGS, base_offset + 1);
685	/* Reset Error flag */
686	outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_E, base_offset + 1);
687
688	mutex_unlock(&priv->lock);
689
690	return 0;
691}
692
693enum quad8_count_function {
694	QUAD8_COUNT_FUNCTION_PULSE_DIRECTION = 0,
695	QUAD8_COUNT_FUNCTION_QUADRATURE_X1,
696	QUAD8_COUNT_FUNCTION_QUADRATURE_X2,
697	QUAD8_COUNT_FUNCTION_QUADRATURE_X4
698};
699
700static enum counter_count_function quad8_count_functions_list[] = {
701	[QUAD8_COUNT_FUNCTION_PULSE_DIRECTION] = COUNTER_COUNT_FUNCTION_PULSE_DIRECTION,
702	[QUAD8_COUNT_FUNCTION_QUADRATURE_X1] = COUNTER_COUNT_FUNCTION_QUADRATURE_X1_A,
703	[QUAD8_COUNT_FUNCTION_QUADRATURE_X2] = COUNTER_COUNT_FUNCTION_QUADRATURE_X2_A,
704	[QUAD8_COUNT_FUNCTION_QUADRATURE_X4] = COUNTER_COUNT_FUNCTION_QUADRATURE_X4
705};
706
707static int quad8_function_get(struct counter_device *counter,
708	struct counter_count *count, size_t *function)
709{
710	struct quad8_iio *const priv = counter->priv;
711	const int id = count->id;
712
713	mutex_lock(&priv->lock);
714
715	if (priv->quadrature_mode[id])
716		switch (priv->quadrature_scale[id]) {
717		case 0:
718			*function = QUAD8_COUNT_FUNCTION_QUADRATURE_X1;
719			break;
720		case 1:
721			*function = QUAD8_COUNT_FUNCTION_QUADRATURE_X2;
722			break;
723		case 2:
724			*function = QUAD8_COUNT_FUNCTION_QUADRATURE_X4;
725			break;
726		}
727	else
728		*function = QUAD8_COUNT_FUNCTION_PULSE_DIRECTION;
729
730	mutex_unlock(&priv->lock);
731
732	return 0;
733}
734
735static int quad8_function_set(struct counter_device *counter,
736	struct counter_count *count, size_t function)
737{
738	struct quad8_iio *const priv = counter->priv;
739	const int id = count->id;
740	unsigned int *const quadrature_mode = priv->quadrature_mode + id;
741	unsigned int *const scale = priv->quadrature_scale + id;
742	unsigned int *const synchronous_mode = priv->synchronous_mode + id;
743	const int base_offset = priv->base + 2 * id + 1;
744	unsigned int mode_cfg;
745	unsigned int idr_cfg;
746
747	mutex_lock(&priv->lock);
748
749	mode_cfg = priv->count_mode[id] << 1;
750	idr_cfg = priv->index_polarity[id] << 1;
751
752	if (function == QUAD8_COUNT_FUNCTION_PULSE_DIRECTION) {
753		*quadrature_mode = 0;
754
755		/* Quadrature scaling only available in quadrature mode */
756		*scale = 0;
757
758		/* Synchronous function not supported in non-quadrature mode */
759		if (*synchronous_mode) {
760			*synchronous_mode = 0;
761			/* Disable synchronous function mode */
762			outb(QUAD8_CTR_IDR | idr_cfg, base_offset);
763		}
764	} else {
765		*quadrature_mode = 1;
766
767		switch (function) {
768		case QUAD8_COUNT_FUNCTION_QUADRATURE_X1:
769			*scale = 0;
770			mode_cfg |= QUAD8_CMR_QUADRATURE_X1;
771			break;
772		case QUAD8_COUNT_FUNCTION_QUADRATURE_X2:
773			*scale = 1;
774			mode_cfg |= QUAD8_CMR_QUADRATURE_X2;
775			break;
776		case QUAD8_COUNT_FUNCTION_QUADRATURE_X4:
777			*scale = 2;
778			mode_cfg |= QUAD8_CMR_QUADRATURE_X4;
779			break;
780		}
781	}
782
783	/* Load mode configuration to Counter Mode Register */
784	outb(QUAD8_CTR_CMR | mode_cfg, base_offset);
785
786	mutex_unlock(&priv->lock);
787
788	return 0;
789}
790
791static void quad8_direction_get(struct counter_device *counter,
792	struct counter_count *count, enum counter_count_direction *direction)
793{
794	const struct quad8_iio *const priv = counter->priv;
795	unsigned int ud_flag;
796	const unsigned int flag_addr = priv->base + 2 * count->id + 1;
797
798	/* U/D flag: nonzero = up, zero = down */
799	ud_flag = inb(flag_addr) & QUAD8_FLAG_UD;
800
801	*direction = (ud_flag) ? COUNTER_COUNT_DIRECTION_FORWARD :
802		COUNTER_COUNT_DIRECTION_BACKWARD;
803}
804
805enum quad8_synapse_action {
806	QUAD8_SYNAPSE_ACTION_NONE = 0,
807	QUAD8_SYNAPSE_ACTION_RISING_EDGE,
808	QUAD8_SYNAPSE_ACTION_FALLING_EDGE,
809	QUAD8_SYNAPSE_ACTION_BOTH_EDGES
810};
811
812static enum counter_synapse_action quad8_index_actions_list[] = {
813	[QUAD8_SYNAPSE_ACTION_NONE] = COUNTER_SYNAPSE_ACTION_NONE,
814	[QUAD8_SYNAPSE_ACTION_RISING_EDGE] = COUNTER_SYNAPSE_ACTION_RISING_EDGE
815};
816
817static enum counter_synapse_action quad8_synapse_actions_list[] = {
818	[QUAD8_SYNAPSE_ACTION_NONE] = COUNTER_SYNAPSE_ACTION_NONE,
819	[QUAD8_SYNAPSE_ACTION_RISING_EDGE] = COUNTER_SYNAPSE_ACTION_RISING_EDGE,
820	[QUAD8_SYNAPSE_ACTION_FALLING_EDGE] = COUNTER_SYNAPSE_ACTION_FALLING_EDGE,
821	[QUAD8_SYNAPSE_ACTION_BOTH_EDGES] = COUNTER_SYNAPSE_ACTION_BOTH_EDGES
822};
823
824static int quad8_action_get(struct counter_device *counter,
825	struct counter_count *count, struct counter_synapse *synapse,
826	size_t *action)
827{
828	struct quad8_iio *const priv = counter->priv;
829	int err;
830	size_t function = 0;
831	const size_t signal_a_id = count->synapses[0].signal->id;
832	enum counter_count_direction direction;
833
834	/* Handle Index signals */
835	if (synapse->signal->id >= 16) {
836		if (priv->preset_enable[count->id])
837			*action = QUAD8_SYNAPSE_ACTION_RISING_EDGE;
838		else
839			*action = QUAD8_SYNAPSE_ACTION_NONE;
840
841		return 0;
842	}
843
844	err = quad8_function_get(counter, count, &function);
845	if (err)
846		return err;
847
848	/* Default action mode */
849	*action = QUAD8_SYNAPSE_ACTION_NONE;
850
851	/* Determine action mode based on current count function mode */
852	switch (function) {
853	case QUAD8_COUNT_FUNCTION_PULSE_DIRECTION:
854		if (synapse->signal->id == signal_a_id)
855			*action = QUAD8_SYNAPSE_ACTION_RISING_EDGE;
856		break;
857	case QUAD8_COUNT_FUNCTION_QUADRATURE_X1:
858		if (synapse->signal->id == signal_a_id) {
859			quad8_direction_get(counter, count, &direction);
860
861			if (direction == COUNTER_COUNT_DIRECTION_FORWARD)
862				*action = QUAD8_SYNAPSE_ACTION_RISING_EDGE;
863			else
864				*action = QUAD8_SYNAPSE_ACTION_FALLING_EDGE;
865		}
866		break;
867	case QUAD8_COUNT_FUNCTION_QUADRATURE_X2:
868		if (synapse->signal->id == signal_a_id)
869			*action = QUAD8_SYNAPSE_ACTION_BOTH_EDGES;
870		break;
871	case QUAD8_COUNT_FUNCTION_QUADRATURE_X4:
872		*action = QUAD8_SYNAPSE_ACTION_BOTH_EDGES;
873		break;
874	}
875
876	return 0;
877}
878
879static const struct counter_ops quad8_ops = {
880	.signal_read = quad8_signal_read,
881	.count_read = quad8_count_read,
882	.count_write = quad8_count_write,
883	.function_get = quad8_function_get,
884	.function_set = quad8_function_set,
885	.action_get = quad8_action_get
886};
887
888static int quad8_index_polarity_get(struct counter_device *counter,
889	struct counter_signal *signal, size_t *index_polarity)
890{
891	const struct quad8_iio *const priv = counter->priv;
892	const size_t channel_id = signal->id - 16;
893
894	*index_polarity = priv->index_polarity[channel_id];
895
896	return 0;
897}
898
899static int quad8_index_polarity_set(struct counter_device *counter,
900	struct counter_signal *signal, size_t index_polarity)
901{
902	struct quad8_iio *const priv = counter->priv;
903	const size_t channel_id = signal->id - 16;
904	const int base_offset = priv->base + 2 * channel_id + 1;
905	unsigned int idr_cfg = index_polarity << 1;
906
907	mutex_lock(&priv->lock);
908
909	idr_cfg |= priv->synchronous_mode[channel_id];
910
911	priv->index_polarity[channel_id] = index_polarity;
912
913	/* Load Index Control configuration to Index Control Register */
914	outb(QUAD8_CTR_IDR | idr_cfg, base_offset);
915
916	mutex_unlock(&priv->lock);
917
918	return 0;
919}
920
921static struct counter_signal_enum_ext quad8_index_pol_enum = {
922	.items = quad8_index_polarity_modes,
923	.num_items = ARRAY_SIZE(quad8_index_polarity_modes),
924	.get = quad8_index_polarity_get,
925	.set = quad8_index_polarity_set
926};
927
928static int quad8_synchronous_mode_get(struct counter_device *counter,
929	struct counter_signal *signal, size_t *synchronous_mode)
930{
931	const struct quad8_iio *const priv = counter->priv;
932	const size_t channel_id = signal->id - 16;
933
934	*synchronous_mode = priv->synchronous_mode[channel_id];
935
936	return 0;
937}
938
939static int quad8_synchronous_mode_set(struct counter_device *counter,
940	struct counter_signal *signal, size_t synchronous_mode)
941{
942	struct quad8_iio *const priv = counter->priv;
943	const size_t channel_id = signal->id - 16;
944	const int base_offset = priv->base + 2 * channel_id + 1;
945	unsigned int idr_cfg = synchronous_mode;
946
947	mutex_lock(&priv->lock);
948
949	idr_cfg |= priv->index_polarity[channel_id] << 1;
950
951	/* Index function must be non-synchronous in non-quadrature mode */
952	if (synchronous_mode && !priv->quadrature_mode[channel_id]) {
953		mutex_unlock(&priv->lock);
954		return -EINVAL;
955	}
956
957	priv->synchronous_mode[channel_id] = synchronous_mode;
958
959	/* Load Index Control configuration to Index Control Register */
960	outb(QUAD8_CTR_IDR | idr_cfg, base_offset);
961
962	mutex_unlock(&priv->lock);
963
964	return 0;
965}
966
967static struct counter_signal_enum_ext quad8_syn_mode_enum = {
968	.items = quad8_synchronous_modes,
969	.num_items = ARRAY_SIZE(quad8_synchronous_modes),
970	.get = quad8_synchronous_mode_get,
971	.set = quad8_synchronous_mode_set
972};
973
974static ssize_t quad8_count_floor_read(struct counter_device *counter,
975	struct counter_count *count, void *private, char *buf)
976{
977	/* Only a floor of 0 is supported */
978	return sprintf(buf, "0\n");
979}
980
981static int quad8_count_mode_get(struct counter_device *counter,
982	struct counter_count *count, size_t *cnt_mode)
983{
984	const struct quad8_iio *const priv = counter->priv;
985
986	/* Map 104-QUAD-8 count mode to Generic Counter count mode */
987	switch (priv->count_mode[count->id]) {
988	case 0:
989		*cnt_mode = COUNTER_COUNT_MODE_NORMAL;
990		break;
991	case 1:
992		*cnt_mode = COUNTER_COUNT_MODE_RANGE_LIMIT;
993		break;
994	case 2:
995		*cnt_mode = COUNTER_COUNT_MODE_NON_RECYCLE;
996		break;
997	case 3:
998		*cnt_mode = COUNTER_COUNT_MODE_MODULO_N;
999		break;
1000	}
1001
1002	return 0;
1003}
1004
1005static int quad8_count_mode_set(struct counter_device *counter,
1006	struct counter_count *count, size_t cnt_mode)
1007{
1008	struct quad8_iio *const priv = counter->priv;
1009	unsigned int mode_cfg;
1010	const int base_offset = priv->base + 2 * count->id + 1;
1011
1012	/* Map Generic Counter count mode to 104-QUAD-8 count mode */
1013	switch (cnt_mode) {
1014	case COUNTER_COUNT_MODE_NORMAL:
1015		cnt_mode = 0;
1016		break;
1017	case COUNTER_COUNT_MODE_RANGE_LIMIT:
1018		cnt_mode = 1;
1019		break;
1020	case COUNTER_COUNT_MODE_NON_RECYCLE:
1021		cnt_mode = 2;
1022		break;
1023	case COUNTER_COUNT_MODE_MODULO_N:
1024		cnt_mode = 3;
1025		break;
1026	}
1027
1028	mutex_lock(&priv->lock);
1029
1030	priv->count_mode[count->id] = cnt_mode;
1031
1032	/* Set count mode configuration value */
1033	mode_cfg = cnt_mode << 1;
1034
1035	/* Add quadrature mode configuration */
1036	if (priv->quadrature_mode[count->id])
1037		mode_cfg |= (priv->quadrature_scale[count->id] + 1) << 3;
1038
1039	/* Load mode configuration to Counter Mode Register */
1040	outb(QUAD8_CTR_CMR | mode_cfg, base_offset);
1041
1042	mutex_unlock(&priv->lock);
1043
1044	return 0;
1045}
1046
1047static struct counter_count_enum_ext quad8_cnt_mode_enum = {
1048	.items = counter_count_mode_str,
1049	.num_items = ARRAY_SIZE(counter_count_mode_str),
1050	.get = quad8_count_mode_get,
1051	.set = quad8_count_mode_set
1052};
1053
1054static ssize_t quad8_count_direction_read(struct counter_device *counter,
1055	struct counter_count *count, void *priv, char *buf)
1056{
1057	enum counter_count_direction dir;
1058
1059	quad8_direction_get(counter, count, &dir);
1060
1061	return sprintf(buf, "%s\n", counter_count_direction_str[dir]);
1062}
1063
1064static ssize_t quad8_count_enable_read(struct counter_device *counter,
1065	struct counter_count *count, void *private, char *buf)
1066{
1067	const struct quad8_iio *const priv = counter->priv;
1068
1069	return sprintf(buf, "%u\n", priv->ab_enable[count->id]);
1070}
1071
1072static ssize_t quad8_count_enable_write(struct counter_device *counter,
1073	struct counter_count *count, void *private, const char *buf, size_t len)
1074{
1075	struct quad8_iio *const priv = counter->priv;
1076	const int base_offset = priv->base + 2 * count->id;
1077	int err;
1078	bool ab_enable;
1079	unsigned int ior_cfg;
1080
1081	err = kstrtobool(buf, &ab_enable);
1082	if (err)
1083		return err;
1084
1085	mutex_lock(&priv->lock);
1086
1087	priv->ab_enable[count->id] = ab_enable;
1088
1089	ior_cfg = ab_enable | priv->preset_enable[count->id] << 1;
1090
1091	/* Load I/O control configuration */
1092	outb(QUAD8_CTR_IOR | ior_cfg, base_offset + 1);
1093
1094	mutex_unlock(&priv->lock);
1095
1096	return len;
1097}
1098
1099static int quad8_error_noise_get(struct counter_device *counter,
1100	struct counter_count *count, size_t *noise_error)
1101{
1102	const struct quad8_iio *const priv = counter->priv;
1103	const int base_offset = priv->base + 2 * count->id + 1;
1104
1105	*noise_error = !!(inb(base_offset) & QUAD8_FLAG_E);
1106
1107	return 0;
1108}
1109
1110static struct counter_count_enum_ext quad8_error_noise_enum = {
1111	.items = quad8_noise_error_states,
1112	.num_items = ARRAY_SIZE(quad8_noise_error_states),
1113	.get = quad8_error_noise_get
1114};
1115
1116static ssize_t quad8_count_preset_read(struct counter_device *counter,
1117	struct counter_count *count, void *private, char *buf)
1118{
1119	const struct quad8_iio *const priv = counter->priv;
1120
1121	return sprintf(buf, "%u\n", priv->preset[count->id]);
1122}
1123
1124static void quad8_preset_register_set(struct quad8_iio *quad8iio, int id,
1125		unsigned int preset)
1126{
1127	const unsigned int base_offset = quad8iio->base + 2 * id;
1128	int i;
1129
1130	quad8iio->preset[id] = preset;
1131
1132	/* Reset Byte Pointer */
1133	outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP, base_offset + 1);
1134
1135	/* Set Preset Register */
1136	for (i = 0; i < 3; i++)
1137		outb(preset >> (8 * i), base_offset);
1138}
1139
1140static ssize_t quad8_count_preset_write(struct counter_device *counter,
1141	struct counter_count *count, void *private, const char *buf, size_t len)
1142{
1143	struct quad8_iio *const priv = counter->priv;
1144	unsigned int preset;
1145	int ret;
1146
1147	ret = kstrtouint(buf, 0, &preset);
1148	if (ret)
1149		return ret;
1150
1151	/* Only 24-bit values are supported */
1152	if (preset > 0xFFFFFF)
1153		return -EINVAL;
1154
1155	mutex_lock(&priv->lock);
1156
1157	quad8_preset_register_set(priv, count->id, preset);
1158
1159	mutex_unlock(&priv->lock);
1160
1161	return len;
1162}
1163
1164static ssize_t quad8_count_ceiling_read(struct counter_device *counter,
1165	struct counter_count *count, void *private, char *buf)
1166{
1167	struct quad8_iio *const priv = counter->priv;
1168
1169	mutex_lock(&priv->lock);
1170
1171	/* Range Limit and Modulo-N count modes use preset value as ceiling */
1172	switch (priv->count_mode[count->id]) {
1173	case 1:
1174	case 3:
1175		mutex_unlock(&priv->lock);
1176		return sprintf(buf, "%u\n", priv->preset[count->id]);
1177	}
1178
1179	mutex_unlock(&priv->lock);
1180
1181	/* By default 0xFFFFFF (24 bits unsigned) is maximum count */
1182	return sprintf(buf, "16777215\n");
1183}
1184
1185static ssize_t quad8_count_ceiling_write(struct counter_device *counter,
1186	struct counter_count *count, void *private, const char *buf, size_t len)
1187{
1188	struct quad8_iio *const priv = counter->priv;
1189	unsigned int ceiling;
1190	int ret;
1191
1192	ret = kstrtouint(buf, 0, &ceiling);
1193	if (ret)
1194		return ret;
1195
1196	/* Only 24-bit values are supported */
1197	if (ceiling > 0xFFFFFF)
1198		return -EINVAL;
1199
1200	mutex_lock(&priv->lock);
1201
1202	/* Range Limit and Modulo-N count modes use preset value as ceiling */
1203	switch (priv->count_mode[count->id]) {
1204	case 1:
1205	case 3:
1206		quad8_preset_register_set(priv, count->id, ceiling);
1207		mutex_unlock(&priv->lock);
1208		return len;
1209	}
1210
1211	mutex_unlock(&priv->lock);
1212
1213	return -EINVAL;
1214}
1215
1216static ssize_t quad8_count_preset_enable_read(struct counter_device *counter,
1217	struct counter_count *count, void *private, char *buf)
1218{
1219	const struct quad8_iio *const priv = counter->priv;
1220
1221	return sprintf(buf, "%u\n", !priv->preset_enable[count->id]);
1222}
1223
1224static ssize_t quad8_count_preset_enable_write(struct counter_device *counter,
1225	struct counter_count *count, void *private, const char *buf, size_t len)
1226{
1227	struct quad8_iio *const priv = counter->priv;
1228	const int base_offset = priv->base + 2 * count->id + 1;
1229	bool preset_enable;
1230	int ret;
1231	unsigned int ior_cfg;
1232
1233	ret = kstrtobool(buf, &preset_enable);
1234	if (ret)
1235		return ret;
1236
1237	/* Preset enable is active low in Input/Output Control register */
1238	preset_enable = !preset_enable;
1239
1240	mutex_lock(&priv->lock);
1241
1242	priv->preset_enable[count->id] = preset_enable;
1243
1244	ior_cfg = priv->ab_enable[count->id] | (unsigned int)preset_enable << 1;
1245
1246	/* Load I/O control configuration to Input / Output Control Register */
1247	outb(QUAD8_CTR_IOR | ior_cfg, base_offset);
1248
1249	mutex_unlock(&priv->lock);
1250
1251	return len;
1252}
1253
1254static ssize_t quad8_signal_cable_fault_read(struct counter_device *counter,
1255					     struct counter_signal *signal,
1256					     void *private, char *buf)
1257{
1258	struct quad8_iio *const priv = counter->priv;
1259	const size_t channel_id = signal->id / 2;
1260	bool disabled;
1261	unsigned int status;
1262	unsigned int fault;
1263
1264	mutex_lock(&priv->lock);
1265
1266	disabled = !(priv->cable_fault_enable & BIT(channel_id));
1267
1268	if (disabled) {
1269		mutex_unlock(&priv->lock);
1270		return -EINVAL;
1271	}
1272
1273	/* Logic 0 = cable fault */
1274	status = inb(priv->base + QUAD8_DIFF_ENCODER_CABLE_STATUS);
1275
1276	mutex_unlock(&priv->lock);
1277
1278	/* Mask respective channel and invert logic */
1279	fault = !(status & BIT(channel_id));
1280
1281	return sprintf(buf, "%u\n", fault);
1282}
1283
1284static ssize_t quad8_signal_cable_fault_enable_read(
1285	struct counter_device *counter, struct counter_signal *signal,
1286	void *private, char *buf)
1287{
1288	const struct quad8_iio *const priv = counter->priv;
1289	const size_t channel_id = signal->id / 2;
1290	const unsigned int enb = !!(priv->cable_fault_enable & BIT(channel_id));
1291
1292	return sprintf(buf, "%u\n", enb);
1293}
1294
1295static ssize_t quad8_signal_cable_fault_enable_write(
1296	struct counter_device *counter, struct counter_signal *signal,
1297	void *private, const char *buf, size_t len)
1298{
1299	struct quad8_iio *const priv = counter->priv;
1300	const size_t channel_id = signal->id / 2;
1301	bool enable;
1302	int ret;
1303	unsigned int cable_fault_enable;
1304
1305	ret = kstrtobool(buf, &enable);
1306	if (ret)
1307		return ret;
1308
1309	mutex_lock(&priv->lock);
1310
1311	if (enable)
1312		priv->cable_fault_enable |= BIT(channel_id);
1313	else
1314		priv->cable_fault_enable &= ~BIT(channel_id);
1315
1316	/* Enable is active low in Differential Encoder Cable Status register */
1317	cable_fault_enable = ~priv->cable_fault_enable;
1318
1319	outb(cable_fault_enable, priv->base + QUAD8_DIFF_ENCODER_CABLE_STATUS);
1320
1321	mutex_unlock(&priv->lock);
1322
1323	return len;
1324}
1325
1326static ssize_t quad8_signal_fck_prescaler_read(struct counter_device *counter,
1327	struct counter_signal *signal, void *private, char *buf)
1328{
1329	const struct quad8_iio *const priv = counter->priv;
1330	const size_t channel_id = signal->id / 2;
1331
1332	return sprintf(buf, "%u\n", priv->fck_prescaler[channel_id]);
1333}
1334
1335static ssize_t quad8_signal_fck_prescaler_write(struct counter_device *counter,
1336	struct counter_signal *signal, void *private, const char *buf,
1337	size_t len)
1338{
1339	struct quad8_iio *const priv = counter->priv;
1340	const size_t channel_id = signal->id / 2;
1341	const int base_offset = priv->base + 2 * channel_id;
1342	u8 prescaler;
1343	int ret;
1344
1345	ret = kstrtou8(buf, 0, &prescaler);
1346	if (ret)
1347		return ret;
1348
1349	mutex_lock(&priv->lock);
1350
1351	priv->fck_prescaler[channel_id] = prescaler;
1352
1353	/* Reset Byte Pointer */
1354	outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP, base_offset + 1);
1355
1356	/* Set filter clock factor */
1357	outb(prescaler, base_offset);
1358	outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP | QUAD8_RLD_PRESET_PSC,
1359	     base_offset + 1);
1360
1361	mutex_unlock(&priv->lock);
1362
1363	return len;
1364}
1365
1366static const struct counter_signal_ext quad8_signal_ext[] = {
1367	{
1368		.name = "cable_fault",
1369		.read = quad8_signal_cable_fault_read
1370	},
1371	{
1372		.name = "cable_fault_enable",
1373		.read = quad8_signal_cable_fault_enable_read,
1374		.write = quad8_signal_cable_fault_enable_write
1375	},
1376	{
1377		.name = "filter_clock_prescaler",
1378		.read = quad8_signal_fck_prescaler_read,
1379		.write = quad8_signal_fck_prescaler_write
1380	}
1381};
1382
1383static const struct counter_signal_ext quad8_index_ext[] = {
1384	COUNTER_SIGNAL_ENUM("index_polarity", &quad8_index_pol_enum),
1385	COUNTER_SIGNAL_ENUM_AVAILABLE("index_polarity",	&quad8_index_pol_enum),
1386	COUNTER_SIGNAL_ENUM("synchronous_mode", &quad8_syn_mode_enum),
1387	COUNTER_SIGNAL_ENUM_AVAILABLE("synchronous_mode", &quad8_syn_mode_enum)
1388};
1389
1390#define QUAD8_QUAD_SIGNAL(_id, _name) {		\
1391	.id = (_id),				\
1392	.name = (_name),			\
1393	.ext = quad8_signal_ext,		\
1394	.num_ext = ARRAY_SIZE(quad8_signal_ext)	\
1395}
1396
1397#define	QUAD8_INDEX_SIGNAL(_id, _name) {	\
1398	.id = (_id),				\
1399	.name = (_name),			\
1400	.ext = quad8_index_ext,			\
1401	.num_ext = ARRAY_SIZE(quad8_index_ext)	\
1402}
1403
1404static struct counter_signal quad8_signals[] = {
1405	QUAD8_QUAD_SIGNAL(0, "Channel 1 Quadrature A"),
1406	QUAD8_QUAD_SIGNAL(1, "Channel 1 Quadrature B"),
1407	QUAD8_QUAD_SIGNAL(2, "Channel 2 Quadrature A"),
1408	QUAD8_QUAD_SIGNAL(3, "Channel 2 Quadrature B"),
1409	QUAD8_QUAD_SIGNAL(4, "Channel 3 Quadrature A"),
1410	QUAD8_QUAD_SIGNAL(5, "Channel 3 Quadrature B"),
1411	QUAD8_QUAD_SIGNAL(6, "Channel 4 Quadrature A"),
1412	QUAD8_QUAD_SIGNAL(7, "Channel 4 Quadrature B"),
1413	QUAD8_QUAD_SIGNAL(8, "Channel 5 Quadrature A"),
1414	QUAD8_QUAD_SIGNAL(9, "Channel 5 Quadrature B"),
1415	QUAD8_QUAD_SIGNAL(10, "Channel 6 Quadrature A"),
1416	QUAD8_QUAD_SIGNAL(11, "Channel 6 Quadrature B"),
1417	QUAD8_QUAD_SIGNAL(12, "Channel 7 Quadrature A"),
1418	QUAD8_QUAD_SIGNAL(13, "Channel 7 Quadrature B"),
1419	QUAD8_QUAD_SIGNAL(14, "Channel 8 Quadrature A"),
1420	QUAD8_QUAD_SIGNAL(15, "Channel 8 Quadrature B"),
1421	QUAD8_INDEX_SIGNAL(16, "Channel 1 Index"),
1422	QUAD8_INDEX_SIGNAL(17, "Channel 2 Index"),
1423	QUAD8_INDEX_SIGNAL(18, "Channel 3 Index"),
1424	QUAD8_INDEX_SIGNAL(19, "Channel 4 Index"),
1425	QUAD8_INDEX_SIGNAL(20, "Channel 5 Index"),
1426	QUAD8_INDEX_SIGNAL(21, "Channel 6 Index"),
1427	QUAD8_INDEX_SIGNAL(22, "Channel 7 Index"),
1428	QUAD8_INDEX_SIGNAL(23, "Channel 8 Index")
1429};
1430
1431#define QUAD8_COUNT_SYNAPSES(_id) {					\
1432	{								\
1433		.actions_list = quad8_synapse_actions_list,		\
1434		.num_actions = ARRAY_SIZE(quad8_synapse_actions_list),	\
1435		.signal = quad8_signals + 2 * (_id)			\
1436	},								\
1437	{								\
1438		.actions_list = quad8_synapse_actions_list,		\
1439		.num_actions = ARRAY_SIZE(quad8_synapse_actions_list),	\
1440		.signal = quad8_signals + 2 * (_id) + 1			\
1441	},								\
1442	{								\
1443		.actions_list = quad8_index_actions_list,		\
1444		.num_actions = ARRAY_SIZE(quad8_index_actions_list),	\
1445		.signal = quad8_signals + 2 * (_id) + 16		\
1446	}								\
1447}
1448
1449static struct counter_synapse quad8_count_synapses[][3] = {
1450	QUAD8_COUNT_SYNAPSES(0), QUAD8_COUNT_SYNAPSES(1),
1451	QUAD8_COUNT_SYNAPSES(2), QUAD8_COUNT_SYNAPSES(3),
1452	QUAD8_COUNT_SYNAPSES(4), QUAD8_COUNT_SYNAPSES(5),
1453	QUAD8_COUNT_SYNAPSES(6), QUAD8_COUNT_SYNAPSES(7)
1454};
1455
1456static const struct counter_count_ext quad8_count_ext[] = {
1457	{
1458		.name = "ceiling",
1459		.read = quad8_count_ceiling_read,
1460		.write = quad8_count_ceiling_write
1461	},
1462	{
1463		.name = "floor",
1464		.read = quad8_count_floor_read
1465	},
1466	COUNTER_COUNT_ENUM("count_mode", &quad8_cnt_mode_enum),
1467	COUNTER_COUNT_ENUM_AVAILABLE("count_mode", &quad8_cnt_mode_enum),
1468	{
1469		.name = "direction",
1470		.read = quad8_count_direction_read
1471	},
1472	{
1473		.name = "enable",
1474		.read = quad8_count_enable_read,
1475		.write = quad8_count_enable_write
1476	},
1477	COUNTER_COUNT_ENUM("error_noise", &quad8_error_noise_enum),
1478	COUNTER_COUNT_ENUM_AVAILABLE("error_noise", &quad8_error_noise_enum),
1479	{
1480		.name = "preset",
1481		.read = quad8_count_preset_read,
1482		.write = quad8_count_preset_write
1483	},
1484	{
1485		.name = "preset_enable",
1486		.read = quad8_count_preset_enable_read,
1487		.write = quad8_count_preset_enable_write
1488	}
1489};
1490
1491#define QUAD8_COUNT(_id, _cntname) {					\
1492	.id = (_id),							\
1493	.name = (_cntname),						\
1494	.functions_list = quad8_count_functions_list,			\
1495	.num_functions = ARRAY_SIZE(quad8_count_functions_list),	\
1496	.synapses = quad8_count_synapses[(_id)],			\
1497	.num_synapses =	2,						\
1498	.ext = quad8_count_ext,						\
1499	.num_ext = ARRAY_SIZE(quad8_count_ext)				\
1500}
1501
1502static struct counter_count quad8_counts[] = {
1503	QUAD8_COUNT(0, "Channel 1 Count"),
1504	QUAD8_COUNT(1, "Channel 2 Count"),
1505	QUAD8_COUNT(2, "Channel 3 Count"),
1506	QUAD8_COUNT(3, "Channel 4 Count"),
1507	QUAD8_COUNT(4, "Channel 5 Count"),
1508	QUAD8_COUNT(5, "Channel 6 Count"),
1509	QUAD8_COUNT(6, "Channel 7 Count"),
1510	QUAD8_COUNT(7, "Channel 8 Count")
1511};
1512
1513static int quad8_probe(struct device *dev, unsigned int id)
1514{
1515	struct iio_dev *indio_dev;
1516	struct quad8_iio *quad8iio;
1517	int i, j;
1518	unsigned int base_offset;
1519	int err;
1520
1521	if (!devm_request_region(dev, base[id], QUAD8_EXTENT, dev_name(dev))) {
1522		dev_err(dev, "Unable to lock port addresses (0x%X-0x%X)\n",
1523			base[id], base[id] + QUAD8_EXTENT);
1524		return -EBUSY;
1525	}
1526
1527	/* Allocate IIO device; this also allocates driver data structure */
1528	indio_dev = devm_iio_device_alloc(dev, sizeof(*quad8iio));
1529	if (!indio_dev)
1530		return -ENOMEM;
1531
1532	/* Initialize IIO device */
1533	indio_dev->info = &quad8_info;
1534	indio_dev->modes = INDIO_DIRECT_MODE;
1535	indio_dev->num_channels = ARRAY_SIZE(quad8_channels);
1536	indio_dev->channels = quad8_channels;
1537	indio_dev->name = dev_name(dev);
1538
1539	/* Initialize Counter device and driver data */
1540	quad8iio = iio_priv(indio_dev);
1541	quad8iio->counter.name = dev_name(dev);
1542	quad8iio->counter.parent = dev;
1543	quad8iio->counter.ops = &quad8_ops;
1544	quad8iio->counter.counts = quad8_counts;
1545	quad8iio->counter.num_counts = ARRAY_SIZE(quad8_counts);
1546	quad8iio->counter.signals = quad8_signals;
1547	quad8iio->counter.num_signals = ARRAY_SIZE(quad8_signals);
1548	quad8iio->counter.priv = quad8iio;
1549	quad8iio->base = base[id];
1550
1551	/* Initialize mutex */
1552	mutex_init(&quad8iio->lock);
1553
1554	/* Reset all counters and disable interrupt function */
1555	outb(QUAD8_CHAN_OP_RESET_COUNTERS, base[id] + QUAD8_REG_CHAN_OP);
1556	/* Set initial configuration for all counters */
1557	for (i = 0; i < QUAD8_NUM_COUNTERS; i++) {
1558		base_offset = base[id] + 2 * i;
1559		/* Reset Byte Pointer */
1560		outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP, base_offset + 1);
1561		/* Reset filter clock factor */
1562		outb(0, base_offset);
1563		outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP | QUAD8_RLD_PRESET_PSC,
1564		     base_offset + 1);
1565		/* Reset Byte Pointer */
1566		outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP, base_offset + 1);
1567		/* Reset Preset Register */
1568		for (j = 0; j < 3; j++)
1569			outb(0x00, base_offset);
1570		/* Reset Borrow, Carry, Compare, and Sign flags */
1571		outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_FLAGS, base_offset + 1);
1572		/* Reset Error flag */
1573		outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_E, base_offset + 1);
1574		/* Binary encoding; Normal count; non-quadrature mode */
1575		outb(QUAD8_CTR_CMR, base_offset + 1);
1576		/* Disable A and B inputs; preset on index; FLG1 as Carry */
1577		outb(QUAD8_CTR_IOR, base_offset + 1);
1578		/* Disable index function; negative index polarity */
1579		outb(QUAD8_CTR_IDR, base_offset + 1);
1580	}
1581	/* Disable Differential Encoder Cable Status for all channels */
1582	outb(0xFF, base[id] + QUAD8_DIFF_ENCODER_CABLE_STATUS);
1583	/* Enable all counters */
1584	outb(QUAD8_CHAN_OP_ENABLE_COUNTERS, base[id] + QUAD8_REG_CHAN_OP);
1585
1586	/* Register IIO device */
1587	err = devm_iio_device_register(dev, indio_dev);
1588	if (err)
1589		return err;
1590
1591	/* Register Counter device */
1592	return devm_counter_register(dev, &quad8iio->counter);
1593}
1594
1595static struct isa_driver quad8_driver = {
1596	.probe = quad8_probe,
1597	.driver = {
1598		.name = "104-quad-8"
1599	}
1600};
1601
1602module_isa_driver(quad8_driver, num_quad8);
1603
1604MODULE_AUTHOR("William Breathitt Gray <vilhelm.gray@gmail.com>");
1605MODULE_DESCRIPTION("ACCES 104-QUAD-8 IIO driver");
1606MODULE_LICENSE("GPL v2");
1607