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1/*
2 * Core driver for the pin muxing portions of the pin control subsystem
3 *
4 * Copyright (C) 2011-2012 ST-Ericsson SA
5 * Written on behalf of Linaro for ST-Ericsson
6 * Based on bits of regulator core, gpio core and clk core
7 *
8 * Author: Linus Walleij <linus.walleij@linaro.org>
9 *
10 * Copyright (C) 2012 NVIDIA CORPORATION. All rights reserved.
11 *
12 * License terms: GNU General Public License (GPL) version 2
13 */
14#define pr_fmt(fmt) "pinmux core: " fmt
15
16#include <linux/kernel.h>
17#include <linux/module.h>
18#include <linux/init.h>
19#include <linux/device.h>
20#include <linux/slab.h>
21#include <linux/radix-tree.h>
22#include <linux/err.h>
23#include <linux/list.h>
24#include <linux/string.h>
25#include <linux/sysfs.h>
26#include <linux/debugfs.h>
27#include <linux/seq_file.h>
28#include <linux/pinctrl/machine.h>
29#include <linux/pinctrl/pinmux.h>
30#include "core.h"
31#include "pinmux.h"
32
33int pinmux_check_ops(struct pinctrl_dev *pctldev)
34{
35 const struct pinmux_ops *ops = pctldev->desc->pmxops;
36 unsigned nfuncs;
37 unsigned selector = 0;
38
39 /* Check that we implement required operations */
40 if (!ops ||
41 !ops->get_functions_count ||
42 !ops->get_function_name ||
43 !ops->get_function_groups ||
44 !ops->enable) {
45 dev_err(pctldev->dev, "pinmux ops lacks necessary functions\n");
46 return -EINVAL;
47 }
48 /* Check that all functions registered have names */
49 nfuncs = ops->get_functions_count(pctldev);
50 while (selector < nfuncs) {
51 const char *fname = ops->get_function_name(pctldev,
52 selector);
53 if (!fname) {
54 dev_err(pctldev->dev, "pinmux ops has no name for function%u\n",
55 selector);
56 return -EINVAL;
57 }
58 selector++;
59 }
60
61 return 0;
62}
63
64int pinmux_validate_map(struct pinctrl_map const *map, int i)
65{
66 if (!map->data.mux.function) {
67 pr_err("failed to register map %s (%d): no function given\n",
68 map->name, i);
69 return -EINVAL;
70 }
71
72 return 0;
73}
74
75/**
76 * pin_request() - request a single pin to be muxed in, typically for GPIO
77 * @pin: the pin number in the global pin space
78 * @owner: a representation of the owner of this pin; typically the device
79 * name that controls its mux function, or the requested GPIO name
80 * @gpio_range: the range matching the GPIO pin if this is a request for a
81 * single GPIO pin
82 */
83static int pin_request(struct pinctrl_dev *pctldev,
84 int pin, const char *owner,
85 struct pinctrl_gpio_range *gpio_range)
86{
87 struct pin_desc *desc;
88 const struct pinmux_ops *ops = pctldev->desc->pmxops;
89 int status = -EINVAL;
90
91 desc = pin_desc_get(pctldev, pin);
92 if (desc == NULL) {
93 dev_err(pctldev->dev,
94 "pin %d is not registered so it cannot be requested\n",
95 pin);
96 goto out;
97 }
98
99 dev_dbg(pctldev->dev, "request pin %d (%s) for %s\n",
100 pin, desc->name, owner);
101
102 if (gpio_range) {
103 /* There's no need to support multiple GPIO requests */
104 if (desc->gpio_owner) {
105 dev_err(pctldev->dev,
106 "pin %s already requested by %s; cannot claim for %s\n",
107 desc->name, desc->gpio_owner, owner);
108 goto out;
109 }
110
111 desc->gpio_owner = owner;
112 } else {
113 if (desc->mux_usecount && strcmp(desc->mux_owner, owner)) {
114 dev_err(pctldev->dev,
115 "pin %s already requested by %s; cannot claim for %s\n",
116 desc->name, desc->mux_owner, owner);
117 goto out;
118 }
119
120 desc->mux_usecount++;
121 if (desc->mux_usecount > 1)
122 return 0;
123
124 desc->mux_owner = owner;
125 }
126
127 /* Let each pin increase references to this module */
128 if (!try_module_get(pctldev->owner)) {
129 dev_err(pctldev->dev,
130 "could not increase module refcount for pin %d\n",
131 pin);
132 status = -EINVAL;
133 goto out_free_pin;
134 }
135
136 /*
137 * If there is no kind of request function for the pin we just assume
138 * we got it by default and proceed.
139 */
140 if (gpio_range && ops->gpio_request_enable)
141 /* This requests and enables a single GPIO pin */
142 status = ops->gpio_request_enable(pctldev, gpio_range, pin);
143 else if (ops->request)
144 status = ops->request(pctldev, pin);
145 else
146 status = 0;
147
148 if (status) {
149 dev_err(pctldev->dev, "request() failed for pin %d\n", pin);
150 module_put(pctldev->owner);
151 }
152
153out_free_pin:
154 if (status) {
155 if (gpio_range) {
156 desc->gpio_owner = NULL;
157 } else {
158 desc->mux_usecount--;
159 if (!desc->mux_usecount)
160 desc->mux_owner = NULL;
161 }
162 }
163out:
164 if (status)
165 dev_err(pctldev->dev, "pin-%d (%s) status %d\n",
166 pin, owner, status);
167
168 return status;
169}
170
171/**
172 * pin_free() - release a single muxed in pin so something else can be muxed
173 * @pctldev: pin controller device handling this pin
174 * @pin: the pin to free
175 * @gpio_range: the range matching the GPIO pin if this is a request for a
176 * single GPIO pin
177 *
178 * This function returns a pointer to the previous owner. This is used
179 * for callers that dynamically allocate an owner name so it can be freed
180 * once the pin is free. This is done for GPIO request functions.
181 */
182static const char *pin_free(struct pinctrl_dev *pctldev, int pin,
183 struct pinctrl_gpio_range *gpio_range)
184{
185 const struct pinmux_ops *ops = pctldev->desc->pmxops;
186 struct pin_desc *desc;
187 const char *owner;
188
189 desc = pin_desc_get(pctldev, pin);
190 if (desc == NULL) {
191 dev_err(pctldev->dev,
192 "pin is not registered so it cannot be freed\n");
193 return NULL;
194 }
195
196 if (!gpio_range) {
197 /*
198 * A pin should not be freed more times than allocated.
199 */
200 if (WARN_ON(!desc->mux_usecount))
201 return NULL;
202 desc->mux_usecount--;
203 if (desc->mux_usecount)
204 return NULL;
205 }
206
207 /*
208 * If there is no kind of request function for the pin we just assume
209 * we got it by default and proceed.
210 */
211 if (gpio_range && ops->gpio_disable_free)
212 ops->gpio_disable_free(pctldev, gpio_range, pin);
213 else if (ops->free)
214 ops->free(pctldev, pin);
215
216 if (gpio_range) {
217 owner = desc->gpio_owner;
218 desc->gpio_owner = NULL;
219 } else {
220 owner = desc->mux_owner;
221 desc->mux_owner = NULL;
222 desc->mux_setting = NULL;
223 }
224
225 module_put(pctldev->owner);
226
227 return owner;
228}
229
230/**
231 * pinmux_request_gpio() - request pinmuxing for a GPIO pin
232 * @pctldev: pin controller device affected
233 * @pin: the pin to mux in for GPIO
234 * @range: the applicable GPIO range
235 */
236int pinmux_request_gpio(struct pinctrl_dev *pctldev,
237 struct pinctrl_gpio_range *range,
238 unsigned pin, unsigned gpio)
239{
240 const char *owner;
241 int ret;
242
243 /* Conjure some name stating what chip and pin this is taken by */
244 owner = kasprintf(GFP_KERNEL, "%s:%d", range->name, gpio);
245 if (!owner)
246 return -EINVAL;
247
248 ret = pin_request(pctldev, pin, owner, range);
249 if (ret < 0)
250 kfree(owner);
251
252 return ret;
253}
254
255/**
256 * pinmux_free_gpio() - release a pin from GPIO muxing
257 * @pctldev: the pin controller device for the pin
258 * @pin: the affected currently GPIO-muxed in pin
259 * @range: applicable GPIO range
260 */
261void pinmux_free_gpio(struct pinctrl_dev *pctldev, unsigned pin,
262 struct pinctrl_gpio_range *range)
263{
264 const char *owner;
265
266 owner = pin_free(pctldev, pin, range);
267 kfree(owner);
268}
269
270/**
271 * pinmux_gpio_direction() - set the direction of a single muxed-in GPIO pin
272 * @pctldev: the pin controller handling this pin
273 * @range: applicable GPIO range
274 * @pin: the affected GPIO pin in this controller
275 * @input: true if we set the pin as input, false for output
276 */
277int pinmux_gpio_direction(struct pinctrl_dev *pctldev,
278 struct pinctrl_gpio_range *range,
279 unsigned pin, bool input)
280{
281 const struct pinmux_ops *ops;
282 int ret;
283
284 ops = pctldev->desc->pmxops;
285
286 if (ops->gpio_set_direction)
287 ret = ops->gpio_set_direction(pctldev, range, pin, input);
288 else
289 ret = 0;
290
291 return ret;
292}
293
294static int pinmux_func_name_to_selector(struct pinctrl_dev *pctldev,
295 const char *function)
296{
297 const struct pinmux_ops *ops = pctldev->desc->pmxops;
298 unsigned nfuncs = ops->get_functions_count(pctldev);
299 unsigned selector = 0;
300
301 /* See if this pctldev has this function */
302 while (selector < nfuncs) {
303 const char *fname = ops->get_function_name(pctldev,
304 selector);
305
306 if (!strcmp(function, fname))
307 return selector;
308
309 selector++;
310 }
311
312 pr_err("%s does not support function %s\n",
313 pinctrl_dev_get_name(pctldev), function);
314 return -EINVAL;
315}
316
317int pinmux_map_to_setting(struct pinctrl_map const *map,
318 struct pinctrl_setting *setting)
319{
320 struct pinctrl_dev *pctldev = setting->pctldev;
321 const struct pinmux_ops *pmxops = pctldev->desc->pmxops;
322 char const * const *groups;
323 unsigned num_groups;
324 int ret;
325 const char *group;
326 int i;
327
328 if (!pmxops) {
329 dev_err(pctldev->dev, "does not support mux function\n");
330 return -EINVAL;
331 }
332
333 ret = pinmux_func_name_to_selector(pctldev, map->data.mux.function);
334 if (ret < 0) {
335 dev_err(pctldev->dev, "invalid function %s in map table\n",
336 map->data.mux.function);
337 return ret;
338 }
339 setting->data.mux.func = ret;
340
341 ret = pmxops->get_function_groups(pctldev, setting->data.mux.func,
342 &groups, &num_groups);
343 if (ret < 0) {
344 dev_err(pctldev->dev, "can't query groups for function %s\n",
345 map->data.mux.function);
346 return ret;
347 }
348 if (!num_groups) {
349 dev_err(pctldev->dev,
350 "function %s can't be selected on any group\n",
351 map->data.mux.function);
352 return -EINVAL;
353 }
354 if (map->data.mux.group) {
355 bool found = false;
356 group = map->data.mux.group;
357 for (i = 0; i < num_groups; i++) {
358 if (!strcmp(group, groups[i])) {
359 found = true;
360 break;
361 }
362 }
363 if (!found) {
364 dev_err(pctldev->dev,
365 "invalid group \"%s\" for function \"%s\"\n",
366 group, map->data.mux.function);
367 return -EINVAL;
368 }
369 } else {
370 group = groups[0];
371 }
372
373 ret = pinctrl_get_group_selector(pctldev, group);
374 if (ret < 0) {
375 dev_err(pctldev->dev, "invalid group %s in map table\n",
376 map->data.mux.group);
377 return ret;
378 }
379 setting->data.mux.group = ret;
380
381 return 0;
382}
383
384void pinmux_free_setting(struct pinctrl_setting const *setting)
385{
386 /* This function is currently unused */
387}
388
389int pinmux_enable_setting(struct pinctrl_setting const *setting)
390{
391 struct pinctrl_dev *pctldev = setting->pctldev;
392 const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
393 const struct pinmux_ops *ops = pctldev->desc->pmxops;
394 int ret;
395 const unsigned *pins;
396 unsigned num_pins;
397 int i;
398 struct pin_desc *desc;
399
400 ret = pctlops->get_group_pins(pctldev, setting->data.mux.group,
401 &pins, &num_pins);
402 if (ret) {
403 const char *gname;
404
405 /* errors only affect debug data, so just warn */
406 gname = pctlops->get_group_name(pctldev,
407 setting->data.mux.group);
408 dev_warn(pctldev->dev,
409 "could not get pins for group %s\n",
410 gname);
411 num_pins = 0;
412 }
413
414 /* Try to allocate all pins in this group, one by one */
415 for (i = 0; i < num_pins; i++) {
416 ret = pin_request(pctldev, pins[i], setting->dev_name, NULL);
417 if (ret) {
418 const char *gname;
419 const char *pname;
420
421 desc = pin_desc_get(pctldev, pins[i]);
422 pname = desc ? desc->name : "non-existing";
423 gname = pctlops->get_group_name(pctldev,
424 setting->data.mux.group);
425 dev_err(pctldev->dev,
426 "could not request pin %d (%s) from group %s "
427 " on device %s\n",
428 pins[i], pname, gname,
429 pinctrl_dev_get_name(pctldev));
430 goto err_pin_request;
431 }
432 }
433
434 /* Now that we have acquired the pins, encode the mux setting */
435 for (i = 0; i < num_pins; i++) {
436 desc = pin_desc_get(pctldev, pins[i]);
437 if (desc == NULL) {
438 dev_warn(pctldev->dev,
439 "could not get pin desc for pin %d\n",
440 pins[i]);
441 continue;
442 }
443 desc->mux_setting = &(setting->data.mux);
444 }
445
446 ret = ops->enable(pctldev, setting->data.mux.func,
447 setting->data.mux.group);
448
449 if (ret)
450 goto err_enable;
451
452 return 0;
453
454err_enable:
455 for (i = 0; i < num_pins; i++) {
456 desc = pin_desc_get(pctldev, pins[i]);
457 if (desc)
458 desc->mux_setting = NULL;
459 }
460err_pin_request:
461 /* On error release all taken pins */
462 while (--i >= 0)
463 pin_free(pctldev, pins[i], NULL);
464
465 return ret;
466}
467
468void pinmux_disable_setting(struct pinctrl_setting const *setting)
469{
470 struct pinctrl_dev *pctldev = setting->pctldev;
471 const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
472 const struct pinmux_ops *ops = pctldev->desc->pmxops;
473 int ret;
474 const unsigned *pins;
475 unsigned num_pins;
476 int i;
477 struct pin_desc *desc;
478
479 ret = pctlops->get_group_pins(pctldev, setting->data.mux.group,
480 &pins, &num_pins);
481 if (ret) {
482 const char *gname;
483
484 /* errors only affect debug data, so just warn */
485 gname = pctlops->get_group_name(pctldev,
486 setting->data.mux.group);
487 dev_warn(pctldev->dev,
488 "could not get pins for group %s\n",
489 gname);
490 num_pins = 0;
491 }
492
493 /* Flag the descs that no setting is active */
494 for (i = 0; i < num_pins; i++) {
495 desc = pin_desc_get(pctldev, pins[i]);
496 if (desc == NULL) {
497 dev_warn(pctldev->dev,
498 "could not get pin desc for pin %d\n",
499 pins[i]);
500 continue;
501 }
502 if (desc->mux_setting == &(setting->data.mux)) {
503 desc->mux_setting = NULL;
504 /* And release the pin */
505 pin_free(pctldev, pins[i], NULL);
506 } else {
507 const char *gname;
508
509 gname = pctlops->get_group_name(pctldev,
510 setting->data.mux.group);
511 dev_warn(pctldev->dev,
512 "not freeing pin %d (%s) as part of "
513 "deactivating group %s - it is already "
514 "used for some other setting",
515 pins[i], desc->name, gname);
516 }
517 }
518
519 if (ops->disable)
520 ops->disable(pctldev, setting->data.mux.func, setting->data.mux.group);
521}
522
523#ifdef CONFIG_DEBUG_FS
524
525/* Called from pincontrol core */
526static int pinmux_functions_show(struct seq_file *s, void *what)
527{
528 struct pinctrl_dev *pctldev = s->private;
529 const struct pinmux_ops *pmxops = pctldev->desc->pmxops;
530 unsigned nfuncs;
531 unsigned func_selector = 0;
532
533 if (!pmxops)
534 return 0;
535
536 mutex_lock(&pctldev->mutex);
537 nfuncs = pmxops->get_functions_count(pctldev);
538 while (func_selector < nfuncs) {
539 const char *func = pmxops->get_function_name(pctldev,
540 func_selector);
541 const char * const *groups;
542 unsigned num_groups;
543 int ret;
544 int i;
545
546 ret = pmxops->get_function_groups(pctldev, func_selector,
547 &groups, &num_groups);
548 if (ret)
549 seq_printf(s, "function %s: COULD NOT GET GROUPS\n",
550 func);
551
552 seq_printf(s, "function: %s, groups = [ ", func);
553 for (i = 0; i < num_groups; i++)
554 seq_printf(s, "%s ", groups[i]);
555 seq_puts(s, "]\n");
556
557 func_selector++;
558 }
559
560 mutex_unlock(&pctldev->mutex);
561
562 return 0;
563}
564
565static int pinmux_pins_show(struct seq_file *s, void *what)
566{
567 struct pinctrl_dev *pctldev = s->private;
568 const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
569 const struct pinmux_ops *pmxops = pctldev->desc->pmxops;
570 unsigned i, pin;
571
572 if (!pmxops)
573 return 0;
574
575 seq_puts(s, "Pinmux settings per pin\n");
576 seq_puts(s, "Format: pin (name): mux_owner gpio_owner hog?\n");
577
578 mutex_lock(&pctldev->mutex);
579
580 /* The pin number can be retrived from the pin controller descriptor */
581 for (i = 0; i < pctldev->desc->npins; i++) {
582 struct pin_desc *desc;
583 bool is_hog = false;
584
585 pin = pctldev->desc->pins[i].number;
586 desc = pin_desc_get(pctldev, pin);
587 /* Skip if we cannot search the pin */
588 if (desc == NULL)
589 continue;
590
591 if (desc->mux_owner &&
592 !strcmp(desc->mux_owner, pinctrl_dev_get_name(pctldev)))
593 is_hog = true;
594
595 seq_printf(s, "pin %d (%s): %s %s%s", pin,
596 desc->name ? desc->name : "unnamed",
597 desc->mux_owner ? desc->mux_owner
598 : "(MUX UNCLAIMED)",
599 desc->gpio_owner ? desc->gpio_owner
600 : "(GPIO UNCLAIMED)",
601 is_hog ? " (HOG)" : "");
602
603 if (desc->mux_setting)
604 seq_printf(s, " function %s group %s\n",
605 pmxops->get_function_name(pctldev,
606 desc->mux_setting->func),
607 pctlops->get_group_name(pctldev,
608 desc->mux_setting->group));
609 else
610 seq_printf(s, "\n");
611 }
612
613 mutex_unlock(&pctldev->mutex);
614
615 return 0;
616}
617
618void pinmux_show_map(struct seq_file *s, struct pinctrl_map const *map)
619{
620 seq_printf(s, "group %s\nfunction %s\n",
621 map->data.mux.group ? map->data.mux.group : "(default)",
622 map->data.mux.function);
623}
624
625void pinmux_show_setting(struct seq_file *s,
626 struct pinctrl_setting const *setting)
627{
628 struct pinctrl_dev *pctldev = setting->pctldev;
629 const struct pinmux_ops *pmxops = pctldev->desc->pmxops;
630 const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
631
632 seq_printf(s, "group: %s (%u) function: %s (%u)\n",
633 pctlops->get_group_name(pctldev, setting->data.mux.group),
634 setting->data.mux.group,
635 pmxops->get_function_name(pctldev, setting->data.mux.func),
636 setting->data.mux.func);
637}
638
639static int pinmux_functions_open(struct inode *inode, struct file *file)
640{
641 return single_open(file, pinmux_functions_show, inode->i_private);
642}
643
644static int pinmux_pins_open(struct inode *inode, struct file *file)
645{
646 return single_open(file, pinmux_pins_show, inode->i_private);
647}
648
649static const struct file_operations pinmux_functions_ops = {
650 .open = pinmux_functions_open,
651 .read = seq_read,
652 .llseek = seq_lseek,
653 .release = single_release,
654};
655
656static const struct file_operations pinmux_pins_ops = {
657 .open = pinmux_pins_open,
658 .read = seq_read,
659 .llseek = seq_lseek,
660 .release = single_release,
661};
662
663void pinmux_init_device_debugfs(struct dentry *devroot,
664 struct pinctrl_dev *pctldev)
665{
666 debugfs_create_file("pinmux-functions", S_IFREG | S_IRUGO,
667 devroot, pctldev, &pinmux_functions_ops);
668 debugfs_create_file("pinmux-pins", S_IFREG | S_IRUGO,
669 devroot, pctldev, &pinmux_pins_ops);
670}
671
672#endif /* CONFIG_DEBUG_FS */