summaryrefslogtreecommitdiff
path: root/arch/sh/kernel/gpio.c
blob: d371653610348313dc4b6481764b9b0ea4a08988 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
/*
 * Pinmuxed GPIO support for SuperH.
 *
 * Copyright (C) 2008 Magnus Damm
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 */

#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/bitops.h>
#include <linux/gpio.h>

static struct pinmux_info *registered_gpio;

static struct pinmux_info *gpio_controller(unsigned gpio)
{
	if (!registered_gpio)
		return NULL;

	if (gpio < registered_gpio->first_gpio)
		return NULL;

	if (gpio > registered_gpio->last_gpio)
		return NULL;

	return registered_gpio;
}

static int enum_in_range(pinmux_enum_t enum_id, struct pinmux_range *r)
{
	if (enum_id < r->begin)
		return 0;

	if (enum_id > r->end)
		return 0;

	return 1;
}

static int read_write_reg(unsigned long reg, unsigned long reg_width,
			  unsigned long field_width, unsigned long in_pos,
			  unsigned long value, int do_write)
{
	unsigned long data, mask, pos;

	data = 0;
	mask = (1 << field_width) - 1;
	pos = reg_width - ((in_pos + 1) * field_width);

#ifdef DEBUG
	pr_info("%s, addr = %lx, value = %ld, pos = %ld, "
		"r_width = %ld, f_width = %ld\n",
		do_write ? "write" : "read", reg, value, pos,
		reg_width, field_width);
#endif

	switch (reg_width) {
	case 8:
		data = ctrl_inb(reg);
		break;
	case 16:
		data = ctrl_inw(reg);
		break;
	case 32:
		data = ctrl_inl(reg);
		break;
	}

	if (!do_write)
		return (data >> pos) & mask;

	data &= ~(mask << pos);
	data |= value << pos;

	switch (reg_width) {
	case 8:
		ctrl_outb(data, reg);
		break;
	case 16:
		ctrl_outw(data, reg);
		break;
	case 32:
		ctrl_outl(data, reg);
		break;
	}
	return 0;
}

static int get_data_reg(struct pinmux_info *gpioc, unsigned gpio,
			struct pinmux_data_reg **drp, int *bitp)
{
	pinmux_enum_t enum_id = gpioc->gpios[gpio].enum_id;
	struct pinmux_data_reg *data_reg;
	int k, n;

	if (!enum_in_range(enum_id, &gpioc->data))
		return -1;

	k = 0;
	while (1) {
		data_reg = gpioc->data_regs + k;

		if (!data_reg->reg_width)
			break;

		for (n = 0; n < data_reg->reg_width; n++) {
			if (data_reg->enum_ids[n] == enum_id) {
				*drp = data_reg;
				*bitp = n;
				return 0;

			}
		}
		k++;
	}

	return -1;
}

static int get_config_reg(struct pinmux_info *gpioc, pinmux_enum_t enum_id,
			  struct pinmux_cfg_reg **crp, int *indexp,
			  unsigned long **cntp)
{
	struct pinmux_cfg_reg *config_reg;
	unsigned long r_width, f_width;
	int k, n;

	k = 0;
	while (1) {
		config_reg = gpioc->cfg_regs + k;

		r_width = config_reg->reg_width;
		f_width = config_reg->field_width;

		if (!r_width)
			break;
		for (n = 0; n < (r_width / f_width) * 1 << f_width; n++) {
			if (config_reg->enum_ids[n] == enum_id) {
				*crp = config_reg;
				*indexp = n;
				*cntp = &config_reg->cnt[n / (1 << f_width)];
				return 0;
			}
		}
		k++;
	}

	return -1;
}

static int get_gpio_enum_id(struct pinmux_info *gpioc, unsigned gpio,
			    int pos, pinmux_enum_t *enum_idp)
{
	pinmux_enum_t enum_id = gpioc->gpios[gpio].enum_id;
	pinmux_enum_t *data = gpioc->gpio_data;
	int k;

	if (!enum_in_range(enum_id, &gpioc->data)) {
		if (!enum_in_range(enum_id, &gpioc->mark)) {
			pr_err("non data/mark enum_id for gpio %d\n", gpio);
			return -1;
		}
	}

	if (pos) {
		*enum_idp = data[pos + 1];
		return pos + 1;
	}

	for (k = 0; k < gpioc->gpio_data_size; k++) {
		if (data[k] == enum_id) {
			*enum_idp = data[k + 1];
			return k + 1;
		}
	}

	pr_err("cannot locate data/mark enum_id for gpio %d\n", gpio);
	return -1;
}

static int write_config_reg(struct pinmux_info *gpioc,
			    struct pinmux_cfg_reg *crp,
			    int index)
{
	unsigned long ncomb, pos, value;

	ncomb = 1 << crp->field_width;
	pos = index / ncomb;
	value = index % ncomb;

	return read_write_reg(crp->reg, crp->reg_width,
			      crp->field_width, pos, value, 1);
}

static int check_config_reg(struct pinmux_info *gpioc,
			    struct pinmux_cfg_reg *crp,
			    int index)
{
	unsigned long ncomb, pos, value;

	ncomb = 1 << crp->field_width;
	pos = index / ncomb;
	value = index % ncomb;

	if (read_write_reg(crp->reg, crp->reg_width,
			   crp->field_width, pos, 0, 0) == value)
		return 0;

	return -1;
}

enum { GPIO_CFG_DRYRUN, GPIO_CFG_REQ, GPIO_CFG_FREE };

int pinmux_config_gpio(struct pinmux_info *gpioc, unsigned gpio,
		       int pinmux_type, int cfg_mode)
{
	struct pinmux_cfg_reg *cr = NULL;
	pinmux_enum_t enum_id;
	struct pinmux_range *range;
	int in_range, pos, index;
	unsigned long *cntp;

	switch (pinmux_type) {

	case PINMUX_TYPE_FUNCTION:
		range = NULL;
		break;

	case PINMUX_TYPE_OUTPUT:
		range = &gpioc->output;
		break;

	case PINMUX_TYPE_INPUT:
		range = &gpioc->input;
		break;

	case PINMUX_TYPE_INPUT_PULLUP:
		range = &gpioc->input_pu;
		break;

	case PINMUX_TYPE_INPUT_PULLDOWN:
		range = &gpioc->input_pd;
		break;

	default:
		goto out_err;
	}

	pos = 0;
	enum_id = 0;
	index = 0;
	while (1) {
		pos = get_gpio_enum_id(gpioc, gpio, pos, &enum_id);
		if (pos <= 0)
			goto out_err;

		if (!enum_id)
			break;

		in_range = enum_in_range(enum_id, &gpioc->function);
		if (!in_range && range) {
			in_range = enum_in_range(enum_id, range);

			if (in_range && enum_id == range->force)
				continue;
		}

		if (!in_range)
			continue;

		if (get_config_reg(gpioc, enum_id, &cr, &index, &cntp) != 0)
			goto out_err;

		switch (cfg_mode) {
		case GPIO_CFG_DRYRUN:
			if (!*cntp || !check_config_reg(gpioc, cr, index))
				continue;
			break;

		case GPIO_CFG_REQ:
			if (write_config_reg(gpioc, cr, index) != 0)
				goto out_err;
			*cntp = *cntp + 1;
			break;

		case GPIO_CFG_FREE:
			*cntp = *cntp - 1;
			break;
		}
	}

	return 0;
 out_err:
	return -1;
}

static DEFINE_SPINLOCK(gpio_lock);

int __gpio_request(unsigned gpio)
{
	struct pinmux_info *gpioc = gpio_controller(gpio);
	struct pinmux_data_reg *dummy;
	unsigned long flags;
	int i, ret, pinmux_type;

	ret = -EINVAL;

	if (!gpioc)
		goto err_out;

	spin_lock_irqsave(&gpio_lock, flags);

	if ((gpioc->gpios[gpio].flags & PINMUX_FLAG_TYPE) != PINMUX_TYPE_NONE)
		goto err_unlock;

	/* setup pin function here if no data is associated with pin */

	if (get_data_reg(gpioc, gpio, &dummy, &i) != 0)
		pinmux_type = PINMUX_TYPE_FUNCTION;
	else
		pinmux_type = PINMUX_TYPE_GPIO;

	if (pinmux_type == PINMUX_TYPE_FUNCTION) {
		if (pinmux_config_gpio(gpioc, gpio,
				       pinmux_type,
				       GPIO_CFG_DRYRUN) != 0)
			goto err_unlock;

		if (pinmux_config_gpio(gpioc, gpio,
				       pinmux_type,
				       GPIO_CFG_REQ) != 0)
			BUG();
	}

	gpioc->gpios[gpio].flags = pinmux_type;

	ret = 0;
 err_unlock:
	spin_unlock_irqrestore(&gpio_lock, flags);
 err_out:
	return ret;
}
EXPORT_SYMBOL(__gpio_request);

void gpio_free(unsigned gpio)
{
	struct pinmux_info *gpioc = gpio_controller(gpio);
	unsigned long flags;
	int pinmux_type;

	if (!gpioc)
		return;

	spin_lock_irqsave(&gpio_lock, flags);

	pinmux_type = gpioc->gpios[gpio].flags & PINMUX_FLAG_TYPE;
	pinmux_config_gpio(gpioc, gpio, pinmux_type, GPIO_CFG_FREE);
	gpioc->gpios[gpio].flags = PINMUX_TYPE_NONE;

	spin_unlock_irqrestore(&gpio_lock, flags);
}
EXPORT_SYMBOL(gpio_free);

static int pinmux_direction(struct pinmux_info *gpioc,
			    unsigned gpio, int new_pinmux_type)
{
	int ret, pinmux_type;

	ret = -EINVAL;
	pinmux_type = gpioc->gpios[gpio].flags & PINMUX_FLAG_TYPE;

	switch (pinmux_type) {
	case PINMUX_TYPE_GPIO:
		break;
	case PINMUX_TYPE_OUTPUT:
	case PINMUX_TYPE_INPUT:
	case PINMUX_TYPE_INPUT_PULLUP:
	case PINMUX_TYPE_INPUT_PULLDOWN:
		pinmux_config_gpio(gpioc, gpio, pinmux_type, GPIO_CFG_FREE);
		break;
	default:
		goto err_out;
	}

	if (pinmux_config_gpio(gpioc, gpio,
			       new_pinmux_type,
			       GPIO_CFG_DRYRUN) != 0)
		goto err_out;

	if (pinmux_config_gpio(gpioc, gpio,
			       new_pinmux_type,
			       GPIO_CFG_REQ) != 0)
		BUG();

	gpioc->gpios[gpio].flags = new_pinmux_type;

	ret = 0;
 err_out:
	return ret;
}

int gpio_direction_input(unsigned gpio)
{
	struct pinmux_info *gpioc = gpio_controller(gpio);
	unsigned long flags;
	int ret = -EINVAL;

	if (!gpioc)
		goto err_out;

	spin_lock_irqsave(&gpio_lock, flags);
	ret = pinmux_direction(gpioc, gpio, PINMUX_TYPE_INPUT);
	spin_unlock_irqrestore(&gpio_lock, flags);
 err_out:
	return ret;
}
EXPORT_SYMBOL(gpio_direction_input);

static int __gpio_get_set_value(struct pinmux_info *gpioc,
				unsigned gpio, int value,
				int do_write)
{
	struct pinmux_data_reg *dr = NULL;
	int bit = 0;

	if (get_data_reg(gpioc, gpio, &dr, &bit) != 0)
		BUG();
	else
		value = read_write_reg(dr->reg, dr->reg_width,
				       1, bit, !!value, do_write);

	return value;
}

int gpio_direction_output(unsigned gpio, int value)
{
	struct pinmux_info *gpioc = gpio_controller(gpio);
	unsigned long flags;
	int ret = -EINVAL;

	if (!gpioc)
		goto err_out;

	spin_lock_irqsave(&gpio_lock, flags);
	__gpio_get_set_value(gpioc, gpio, value, 1);
	ret = pinmux_direction(gpioc, gpio, PINMUX_TYPE_OUTPUT);
	spin_unlock_irqrestore(&gpio_lock, flags);
 err_out:
	return ret;
}
EXPORT_SYMBOL(gpio_direction_output);

int gpio_get_value(unsigned gpio)
{
	struct pinmux_info *gpioc = gpio_controller(gpio);
	unsigned long flags;
	int value = 0;

	if (!gpioc)
		BUG();
	else {
		spin_lock_irqsave(&gpio_lock, flags);
		value = __gpio_get_set_value(gpioc, gpio, 0, 0);
		spin_unlock_irqrestore(&gpio_lock, flags);
	}

	return value;
}
EXPORT_SYMBOL(gpio_get_value);

void gpio_set_value(unsigned gpio, int value)
{
	struct pinmux_info *gpioc = gpio_controller(gpio);
	unsigned long flags;

	if (!gpioc)
		BUG();
	else {
		spin_lock_irqsave(&gpio_lock, flags);
		__gpio_get_set_value(gpioc, gpio, value, 1);
		spin_unlock_irqrestore(&gpio_lock, flags);
	}
}
EXPORT_SYMBOL(gpio_set_value);

int register_pinmux(struct pinmux_info *pip)
{
	registered_gpio = pip;
	pr_info("pinmux: %s handling gpio %d -> %d\n",
		pip->name, pip->first_gpio, pip->last_gpio);

	return 0;
}