summaryrefslogtreecommitdiffstats
path: root/drivers/pinctrl/aspeed/pinctrl-aspeed.c
blob: d6b849552a1e7a627376f3e0a40f41fd30bea99d (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
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (C) 2016 IBM Corp.
 */

#include <linux/mfd/syscon.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/string.h>
#include "../core.h"
#include "pinctrl-aspeed.h"

int aspeed_pinctrl_get_groups_count(struct pinctrl_dev *pctldev)
{
	struct aspeed_pinctrl_data *pdata = pinctrl_dev_get_drvdata(pctldev);

	return pdata->pinmux.ngroups;
}

const char *aspeed_pinctrl_get_group_name(struct pinctrl_dev *pctldev,
		unsigned int group)
{
	struct aspeed_pinctrl_data *pdata = pinctrl_dev_get_drvdata(pctldev);

	return pdata->pinmux.groups[group].name;
}

int aspeed_pinctrl_get_group_pins(struct pinctrl_dev *pctldev,
				  unsigned int group, const unsigned int **pins,
				  unsigned int *npins)
{
	struct aspeed_pinctrl_data *pdata = pinctrl_dev_get_drvdata(pctldev);

	*pins = &pdata->pinmux.groups[group].pins[0];
	*npins = pdata->pinmux.groups[group].npins;

	return 0;
}

void aspeed_pinctrl_pin_dbg_show(struct pinctrl_dev *pctldev,
				 struct seq_file *s, unsigned int offset)
{
	seq_printf(s, " %s", dev_name(pctldev->dev));
}

int aspeed_pinmux_get_fn_count(struct pinctrl_dev *pctldev)
{
	struct aspeed_pinctrl_data *pdata = pinctrl_dev_get_drvdata(pctldev);

	return pdata->pinmux.nfunctions;
}

const char *aspeed_pinmux_get_fn_name(struct pinctrl_dev *pctldev,
				      unsigned int function)
{
	struct aspeed_pinctrl_data *pdata = pinctrl_dev_get_drvdata(pctldev);

	return pdata->pinmux.functions[function].name;
}

int aspeed_pinmux_get_fn_groups(struct pinctrl_dev *pctldev,
				unsigned int function,
				const char * const **groups,
				unsigned int * const num_groups)
{
	struct aspeed_pinctrl_data *pdata = pinctrl_dev_get_drvdata(pctldev);

	*groups = pdata->pinmux.functions[function].groups;
	*num_groups = pdata->pinmux.functions[function].ngroups;

	return 0;
}

static int aspeed_sig_expr_enable(struct aspeed_pinmux_data *ctx,
				  const struct aspeed_sig_expr *expr)
{
	int ret;

	pr_debug("Enabling signal %s for %s\n", expr->signal,
		 expr->function);

	ret = aspeed_sig_expr_eval(ctx, expr, true);
	if (ret < 0)
		return ret;

	if (!ret)
		return aspeed_sig_expr_set(ctx, expr, true);

	return 0;
}

static int aspeed_sig_expr_disable(struct aspeed_pinmux_data *ctx,
				   const struct aspeed_sig_expr *expr)
{
	int ret;

	pr_debug("Disabling signal %s for %s\n", expr->signal,
		 expr->function);

	ret = aspeed_sig_expr_eval(ctx, expr, true);
	if (ret < 0)
		return ret;

	if (ret)
		return aspeed_sig_expr_set(ctx, expr, false);

	return 0;
}

/**
 * Disable a signal on a pin by disabling all provided signal expressions.
 *
 * @ctx: The pinmux context
 * @exprs: The list of signal expressions (from a priority level on a pin)
 *
 * Return: 0 if all expressions are disabled, otherwise a negative error code
 */
static int aspeed_disable_sig(struct aspeed_pinmux_data *ctx,
			      const struct aspeed_sig_expr **exprs)
{
	int ret = 0;

	if (!exprs)
		return true;

	while (*exprs && !ret) {
		ret = aspeed_sig_expr_disable(ctx, *exprs);
		exprs++;
	}

	return ret;
}

/**
 * Search for the signal expression needed to enable the pin's signal for the
 * requested function.
 *
 * @exprs: List of signal expressions (haystack)
 * @name: The name of the requested function (needle)
 *
 * Return: A pointer to the signal expression whose function tag matches the
 * provided name, otherwise NULL.
 *
 */
static const struct aspeed_sig_expr *aspeed_find_expr_by_name(
		const struct aspeed_sig_expr **exprs, const char *name)
{
	while (*exprs) {
		if (strcmp((*exprs)->function, name) == 0)
			return *exprs;
		exprs++;
	}

	return NULL;
}

static char *get_defined_attribute(const struct aspeed_pin_desc *pdesc,
				   const char *(*get)(
					   const struct aspeed_sig_expr *))
{
	char *found = NULL;
	size_t len = 0;
	const struct aspeed_sig_expr ***prios, **funcs, *expr;

	prios = pdesc->prios;

	while ((funcs = *prios)) {
		while ((expr = *funcs)) {
			const char *str = get(expr);
			size_t delta = strlen(str) + 2;
			char *expanded;

			expanded = krealloc(found, len + delta + 1, GFP_KERNEL);
			if (!expanded) {
				kfree(found);
				return expanded;
			}

			found = expanded;
			found[len] = '\0';
			len += delta;

			strcat(found, str);
			strcat(found, ", ");

			funcs++;
		}
		prios++;
	}

	if (len < 2) {
		kfree(found);
		return NULL;
	}

	found[len - 2] = '\0';

	return found;
}

static const char *aspeed_sig_expr_function(const struct aspeed_sig_expr *expr)
{
	return expr->function;
}

static char *get_defined_functions(const struct aspeed_pin_desc *pdesc)
{
	return get_defined_attribute(pdesc, aspeed_sig_expr_function);
}

static const char *aspeed_sig_expr_signal(const struct aspeed_sig_expr *expr)
{
	return expr->signal;
}

static char *get_defined_signals(const struct aspeed_pin_desc *pdesc)
{
	return get_defined_attribute(pdesc, aspeed_sig_expr_signal);
}

int aspeed_pinmux_set_mux(struct pinctrl_dev *pctldev, unsigned int function,
			  unsigned int group)
{
	int i;
	int ret;
	struct aspeed_pinctrl_data *pdata = pinctrl_dev_get_drvdata(pctldev);
	const struct aspeed_pin_group *pgroup = &pdata->pinmux.groups[group];
	const struct aspeed_pin_function *pfunc =
		&pdata->pinmux.functions[function];

	for (i = 0; i < pgroup->npins; i++) {
		int pin = pgroup->pins[i];
		const struct aspeed_pin_desc *pdesc = pdata->pins[pin].drv_data;
		const struct aspeed_sig_expr *expr = NULL;
		const struct aspeed_sig_expr **funcs;
		const struct aspeed_sig_expr ***prios;

		pr_debug("Muxing pin %s for %s\n", pdesc->name, pfunc->name);

		if (!pdesc)
			return -EINVAL;

		prios = pdesc->prios;

		if (!prios)
			continue;

		/* Disable functions at a higher priority than that requested */
		while ((funcs = *prios)) {
			expr = aspeed_find_expr_by_name(funcs, pfunc->name);

			if (expr)
				break;

			ret = aspeed_disable_sig(&pdata->pinmux, funcs);
			if (ret)
				return ret;

			prios++;
		}

		if (!expr) {
			char *functions = get_defined_functions(pdesc);
			char *signals = get_defined_signals(pdesc);

			pr_warn("No function %s found on pin %s (%d). Found signal(s) %s for function(s) %s\n",
				pfunc->name, pdesc->name, pin, signals,
				functions);
			kfree(signals);
			kfree(functions);

			return -ENXIO;
		}

		ret = aspeed_sig_expr_enable(&pdata->pinmux, expr);
		if (ret)
			return ret;

		pr_debug("Muxed pin %s as %s for %s\n", pdesc->name, expr->signal,
			 expr->function);
	}

	return 0;
}

static bool aspeed_expr_is_gpio(const struct aspeed_sig_expr *expr)
{
	/*
	 * The signal type is GPIO if the signal name has "GPI" as a prefix.
	 * strncmp (rather than strcmp) is used to implement the prefix
	 * requirement.
	 *
	 * expr->signal might look like "GPIOB1" in the GPIO case.
	 * expr->signal might look like "GPIT0" in the GPI case.
	 */
	return strncmp(expr->signal, "GPI", 3) == 0;
}

static bool aspeed_gpio_in_exprs(const struct aspeed_sig_expr **exprs)
{
	if (!exprs)
		return false;

	while (*exprs) {
		if (aspeed_expr_is_gpio(*exprs))
			return true;
		exprs++;
	}

	return false;
}

int aspeed_gpio_request_enable(struct pinctrl_dev *pctldev,
			       struct pinctrl_gpio_range *range,
			       unsigned int offset)
{
	int ret;
	struct aspeed_pinctrl_data *pdata = pinctrl_dev_get_drvdata(pctldev);
	const struct aspeed_pin_desc *pdesc = pdata->pins[offset].drv_data;
	const struct aspeed_sig_expr ***prios, **funcs, *expr;

	if (!pdesc)
		return -EINVAL;

	prios = pdesc->prios;

	if (!prios)
		return -ENXIO;

	pr_debug("Muxing pin %s for GPIO\n", pdesc->name);

	/* Disable any functions of higher priority than GPIO */
	while ((funcs = *prios)) {
		if (aspeed_gpio_in_exprs(funcs))
			break;

		ret = aspeed_disable_sig(&pdata->pinmux, funcs);
		if (ret)
			return ret;

		prios++;
	}

	if (!funcs) {
		char *signals = get_defined_signals(pdesc);

		pr_warn("No GPIO signal type found on pin %s (%d). Found: %s\n",
			pdesc->name, offset, signals);
		kfree(signals);

		return -ENXIO;
	}

	expr = *funcs;

	/*
	 * Disabling all higher-priority expressions is enough to enable the
	 * lowest-priority signal type. As such it has no associated
	 * expression.
	 */
	if (!expr) {
		pr_debug("Muxed pin %s as GPIO\n", pdesc->name);
		return 0;
	}

	/*
	 * If GPIO is not the lowest priority signal type, assume there is only
	 * one expression defined to enable the GPIO function
	 */
	ret = aspeed_sig_expr_enable(&pdata->pinmux, expr);
	if (ret)
		return ret;

	pr_debug("Muxed pin %s as %s\n", pdesc->name, expr->signal);

	return 0;
}

int aspeed_pinctrl_probe(struct platform_device *pdev,
			 struct pinctrl_desc *pdesc,
			 struct aspeed_pinctrl_data *pdata)
{
	struct device *parent;
	struct pinctrl_dev *pctl;

	parent = pdev->dev.parent;
	if (!parent) {
		dev_err(&pdev->dev, "No parent for syscon pincontroller\n");
		return -ENODEV;
	}

	pdata->scu = syscon_node_to_regmap(parent->of_node);
	if (IS_ERR(pdata->scu)) {
		dev_err(&pdev->dev, "No regmap for syscon pincontroller parent\n");
		return PTR_ERR(pdata->scu);
	}

	pdata->pinmux.maps[ASPEED_IP_SCU] = pdata->scu;

	pctl = pinctrl_register(pdesc, &pdev->dev, pdata);

	if (IS_ERR(pctl)) {
		dev_err(&pdev->dev, "Failed to register pinctrl\n");
		return PTR_ERR(pctl);
	}

	platform_set_drvdata(pdev, pdata);

	return 0;
}

static inline bool pin_in_config_range(unsigned int offset,
		const struct aspeed_pin_config *config)
{
	return offset >= config->pins[0] && offset <= config->pins[1];
}

static inline const struct aspeed_pin_config *find_pinconf_config(
		const struct aspeed_pinctrl_data *pdata,
		unsigned int offset,
		enum pin_config_param param)
{
	unsigned int i;

	for (i = 0; i < pdata->nconfigs; i++) {
		if (param == pdata->configs[i].param &&
				pin_in_config_range(offset, &pdata->configs[i]))
			return &pdata->configs[i];
	}

	return NULL;
}

enum aspeed_pin_config_map_type { MAP_TYPE_ARG, MAP_TYPE_VAL };

static const struct aspeed_pin_config_map *find_pinconf_map(
		const struct aspeed_pinctrl_data *pdata,
		enum pin_config_param param,
		enum aspeed_pin_config_map_type type,
		s64 value)
{
	int i;

	for (i = 0; i < pdata->nconfmaps; i++) {
		const struct aspeed_pin_config_map *elem;
		bool match;

		elem = &pdata->confmaps[i];

		switch (type) {
		case MAP_TYPE_ARG:
			match = (elem->arg == -1 || elem->arg == value);
			break;
		case MAP_TYPE_VAL:
			match = (elem->val == value);
			break;
		}

		if (param == elem->param && match)
			return elem;
	}

	return NULL;
}

int aspeed_pin_config_get(struct pinctrl_dev *pctldev, unsigned int offset,
		unsigned long *config)
{
	const enum pin_config_param param = pinconf_to_config_param(*config);
	const struct aspeed_pin_config_map *pmap;
	const struct aspeed_pinctrl_data *pdata;
	const struct aspeed_pin_config *pconf;
	unsigned int val;
	int rc = 0;
	u32 arg;

	pdata = pinctrl_dev_get_drvdata(pctldev);
	pconf = find_pinconf_config(pdata, offset, param);
	if (!pconf)
		return -ENOTSUPP;

	rc = regmap_read(pdata->scu, pconf->reg, &val);
	if (rc < 0)
		return rc;

	pmap = find_pinconf_map(pdata, param, MAP_TYPE_VAL,
			(val & pconf->mask) >> __ffs(pconf->mask));

	if (!pmap)
		return -EINVAL;

	if (param == PIN_CONFIG_DRIVE_STRENGTH)
		arg = (u32) pmap->arg;
	else if (param == PIN_CONFIG_BIAS_PULL_DOWN)
		arg = !!pmap->arg;
	else
		arg = 1;

	if (!arg)
		return -EINVAL;

	*config = pinconf_to_config_packed(param, arg);

	return 0;
}

int aspeed_pin_config_set(struct pinctrl_dev *pctldev, unsigned int offset,
		unsigned long *configs, unsigned int num_configs)
{
	const struct aspeed_pinctrl_data *pdata;
	unsigned int i;
	int rc = 0;

	pdata = pinctrl_dev_get_drvdata(pctldev);

	for (i = 0; i < num_configs; i++) {
		const struct aspeed_pin_config_map *pmap;
		const struct aspeed_pin_config *pconf;
		enum pin_config_param param;
		unsigned int val;
		u32 arg;

		param = pinconf_to_config_param(configs[i]);
		arg = pinconf_to_config_argument(configs[i]);

		pconf = find_pinconf_config(pdata, offset, param);
		if (!pconf)
			return -ENOTSUPP;

		pmap = find_pinconf_map(pdata, param, MAP_TYPE_ARG, arg);

		if (WARN_ON(!pmap))
			return -EINVAL;

		val = pmap->val << __ffs(pconf->mask);

		rc = regmap_update_bits(pdata->scu, pconf->reg,
					pconf->mask, val);

		if (rc < 0)
			return rc;

		pr_debug("%s: Set SCU%02X[0x%08X]=0x%X for param %d(=%d) on pin %d\n",
				__func__, pconf->reg, pconf->mask,
				val, param, arg, offset);
	}

	return 0;
}

int aspeed_pin_config_group_get(struct pinctrl_dev *pctldev,
		unsigned int selector,
		unsigned long *config)
{
	const unsigned int *pins;
	unsigned int npins;
	int rc;

	rc = aspeed_pinctrl_get_group_pins(pctldev, selector, &pins, &npins);
	if (rc < 0)
		return rc;

	if (!npins)
		return -ENODEV;

	rc = aspeed_pin_config_get(pctldev, pins[0], config);

	return rc;
}

int aspeed_pin_config_group_set(struct pinctrl_dev *pctldev,
		unsigned int selector,
		unsigned long *configs,
		unsigned int num_configs)
{
	const unsigned int *pins;
	unsigned int npins;
	int rc;
	int i;

	pr_debug("%s: Fetching pins for group selector %d\n",
			__func__, selector);
	rc = aspeed_pinctrl_get_group_pins(pctldev, selector, &pins, &npins);
	if (rc < 0)
		return rc;

	for (i = 0; i < npins; i++) {
		rc = aspeed_pin_config_set(pctldev, pins[i], configs,
				num_configs);
		if (rc < 0)
			return rc;
	}

	return 0;
}