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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 desc->mux_usecount--;
198 if (desc->mux_usecount)
199 return NULL;
200 }
201
202 /*
203 * If there is no kind of request function for the pin we just assume
204 * we got it by default and proceed.
205 */
206 if (gpio_range && ops->gpio_disable_free)
207 ops->gpio_disable_free(pctldev, gpio_range, pin);
208 else if (ops->free)
209 ops->free(pctldev, pin);
210
211 if (gpio_range) {
212 owner = desc->gpio_owner;
213 desc->gpio_owner = NULL;
214 } else {
215 owner = desc->mux_owner;
216 desc->mux_owner = NULL;
217 desc->mux_setting = NULL;
218 }
219
220 module_put(pctldev->owner);
221
222 return owner;
223}
224
225/**
226 * pinmux_request_gpio() - request pinmuxing for a GPIO pin
227 * @pctldev: pin controller device affected
228 * @pin: the pin to mux in for GPIO
229 * @range: the applicable GPIO range
230 */
231int pinmux_request_gpio(struct pinctrl_dev *pctldev,
232 struct pinctrl_gpio_range *range,
233 unsigned pin, unsigned gpio)
234{
235 char gpiostr[16];
236 const char *owner;
237 int ret;
238
239 /* Conjure some name stating what chip and pin this is taken by */
240 snprintf(gpiostr, 15, "%s:%d", range->name, gpio);
241
242 owner = kstrdup(gpiostr, GFP_KERNEL);
243 if (!owner)
244 return -EINVAL;
245
246 ret = pin_request(pctldev, pin, owner, range);
247 if (ret < 0)
248 kfree(owner);
249
250 return ret;
251}
252
253/**
254 * pinmux_free_gpio() - release a pin from GPIO muxing
255 * @pctldev: the pin controller device for the pin
256 * @pin: the affected currently GPIO-muxed in pin
257 * @range: applicable GPIO range
258 */
259void pinmux_free_gpio(struct pinctrl_dev *pctldev, unsigned pin,
260 struct pinctrl_gpio_range *range)
261{
262 const char *owner;
263
264 owner = pin_free(pctldev, pin, range);
265 kfree(owner);
266}
267
268/**
269 * pinmux_gpio_direction() - set the direction of a single muxed-in GPIO pin
270 * @pctldev: the pin controller handling this pin
271 * @range: applicable GPIO range
272 * @pin: the affected GPIO pin in this controller
273 * @input: true if we set the pin as input, false for output
274 */
275int pinmux_gpio_direction(struct pinctrl_dev *pctldev,
276 struct pinctrl_gpio_range *range,
277 unsigned pin, bool input)
278{
279 const struct pinmux_ops *ops;
280 int ret;
281
282 ops = pctldev->desc->pmxops;
283
284 if (ops->gpio_set_direction)
285 ret = ops->gpio_set_direction(pctldev, range, pin, input);
286 else
287 ret = 0;
288
289 return ret;
290}
291
292static int pinmux_func_name_to_selector(struct pinctrl_dev *pctldev,
293 const char *function)
294{
295 const struct pinmux_ops *ops = pctldev->desc->pmxops;
296 unsigned nfuncs = ops->get_functions_count(pctldev);
297 unsigned selector = 0;
298
299 /* See if this pctldev has this function */
300 while (selector < nfuncs) {
301 const char *fname = ops->get_function_name(pctldev,
302 selector);
303
304 if (!strcmp(function, fname))
305 return selector;
306
307 selector++;
308 }
309
310 pr_err("%s does not support function %s\n",
311 pinctrl_dev_get_name(pctldev), function);
312 return -EINVAL;
313}
314
315int pinmux_map_to_setting(struct pinctrl_map const *map,
316 struct pinctrl_setting *setting)
317{
318 struct pinctrl_dev *pctldev = setting->pctldev;
319 const struct pinmux_ops *pmxops = pctldev->desc->pmxops;
320 const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
321 char const * const *groups;
322 unsigned num_groups;
323 int ret;
324 const char *group;
325 int i;
326 const unsigned *pins;
327 unsigned num_pins;
328
329 if (!pmxops) {
330 dev_err(pctldev->dev, "does not support mux function\n");
331 return -EINVAL;
332 }
333
334 ret = pinmux_func_name_to_selector(pctldev, map->data.mux.function);
335 if (ret < 0) {
336 dev_err(pctldev->dev, "invalid function %s in map table\n",
337 map->data.mux.function);
338 return ret;
339 }
340 setting->data.mux.func = ret;
341
342 ret = pmxops->get_function_groups(pctldev, setting->data.mux.func,
343 &groups, &num_groups);
344 if (ret < 0) {
345 dev_err(pctldev->dev, "can't query groups for function %s\n",
346 map->data.mux.function);
347 return ret;
348 }
349 if (!num_groups) {
350 dev_err(pctldev->dev,
351 "function %s can't be selected on any group\n",
352 map->data.mux.function);
353 return -EINVAL;
354 }
355 if (map->data.mux.group) {
356 bool found = false;
357 group = map->data.mux.group;
358 for (i = 0; i < num_groups; i++) {
359 if (!strcmp(group, groups[i])) {
360 found = true;
361 break;
362 }
363 }
364 if (!found) {
365 dev_err(pctldev->dev,
366 "invalid group \"%s\" for function \"%s\"\n",
367 group, map->data.mux.function);
368 return -EINVAL;
369 }
370 } else {
371 group = groups[0];
372 }
373
374 ret = pinctrl_get_group_selector(pctldev, group);
375 if (ret < 0) {
376 dev_err(pctldev->dev, "invalid group %s in map table\n",
377 map->data.mux.group);
378 return ret;
379 }
380 setting->data.mux.group = ret;
381
382 ret = pctlops->get_group_pins(pctldev, setting->data.mux.group, &pins,
383 &num_pins);
384 if (ret) {
385 dev_err(pctldev->dev,
386 "could not get pins for device %s group selector %d\n",
387 pinctrl_dev_get_name(pctldev), setting->data.mux.group);
388 return -ENODEV;
389 }
390
391 /* Try to allocate all pins in this group, one by one */
392 for (i = 0; i < num_pins; i++) {
393 ret = pin_request(pctldev, pins[i], map->dev_name, NULL);
394 if (ret) {
395 dev_err(pctldev->dev,
396 "could not request pin %d on device %s\n",
397 pins[i], pinctrl_dev_get_name(pctldev));
398 /* On error release all taken pins */
399 i--; /* this pin just failed */
400 for (; i >= 0; i--)
401 pin_free(pctldev, pins[i], NULL);
402 return -ENODEV;
403 }
404 }
405
406 return 0;
407}
408
409void pinmux_free_setting(struct pinctrl_setting const *setting)
410{
411 struct pinctrl_dev *pctldev = setting->pctldev;
412 const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
413 const unsigned *pins;
414 unsigned num_pins;
415 int ret;
416 int i;
417
418 ret = pctlops->get_group_pins(pctldev, setting->data.mux.group,
419 &pins, &num_pins);
420 if (ret) {
421 dev_err(pctldev->dev,
422 "could not get pins for device %s group selector %d\n",
423 pinctrl_dev_get_name(pctldev), setting->data.mux.group);
424 return;
425 }
426
427 for (i = 0; i < num_pins; i++)
428 pin_free(pctldev, pins[i], NULL);
429}
430
431int pinmux_enable_setting(struct pinctrl_setting const *setting)
432{
433 struct pinctrl_dev *pctldev = setting->pctldev;
434 const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
435 const struct pinmux_ops *ops = pctldev->desc->pmxops;
436 int ret;
437 const unsigned *pins;
438 unsigned num_pins;
439 int i;
440 struct pin_desc *desc;
441
442 ret = pctlops->get_group_pins(pctldev, setting->data.mux.group,
443 &pins, &num_pins);
444 if (ret) {
445 /* errors only affect debug data, so just warn */
446 dev_warn(pctldev->dev,
447 "could not get pins for group selector %d\n",
448 setting->data.mux.group);
449 num_pins = 0;
450 }
451
452 for (i = 0; i < num_pins; i++) {
453 desc = pin_desc_get(pctldev, pins[i]);
454 if (desc == NULL) {
455 dev_warn(pctldev->dev,
456 "could not get pin desc for pin %d\n",
457 pins[i]);
458 continue;
459 }
460 desc->mux_setting = &(setting->data.mux);
461 }
462
463 return ops->enable(pctldev, setting->data.mux.func,
464 setting->data.mux.group);
465}
466
467void pinmux_disable_setting(struct pinctrl_setting const *setting)
468{
469 struct pinctrl_dev *pctldev = setting->pctldev;
470 const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
471 const struct pinmux_ops *ops = pctldev->desc->pmxops;
472 int ret;
473 const unsigned *pins;
474 unsigned num_pins;
475 int i;
476 struct pin_desc *desc;
477
478 ret = pctlops->get_group_pins(pctldev, setting->data.mux.group,
479 &pins, &num_pins);
480 if (ret) {
481 /* errors only affect debug data, so just warn */
482 dev_warn(pctldev->dev,
483 "could not get pins for group selector %d\n",
484 setting->data.mux.group);
485 num_pins = 0;
486 }
487
488 for (i = 0; i < num_pins; i++) {
489 desc = pin_desc_get(pctldev, pins[i]);
490 if (desc == NULL) {
491 dev_warn(pctldev->dev,
492 "could not get pin desc for pin %d\n",
493 pins[i]);
494 continue;
495 }
496 desc->mux_setting = NULL;
497 }
498
499 if (ops->disable)
500 ops->disable(pctldev, setting->data.mux.func, setting->data.mux.group);
501}
502
503#ifdef CONFIG_DEBUG_FS
504
505/* Called from pincontrol core */
506static int pinmux_functions_show(struct seq_file *s, void *what)
507{
508 struct pinctrl_dev *pctldev = s->private;
509 const struct pinmux_ops *pmxops = pctldev->desc->pmxops;
510 unsigned nfuncs;
511 unsigned func_selector = 0;
512
513 if (!pmxops)
514 return 0;
515
516 mutex_lock(&pinctrl_mutex);
517 nfuncs = pmxops->get_functions_count(pctldev);
518 while (func_selector < nfuncs) {
519 const char *func = pmxops->get_function_name(pctldev,
520 func_selector);
521 const char * const *groups;
522 unsigned num_groups;
523 int ret;
524 int i;
525
526 ret = pmxops->get_function_groups(pctldev, func_selector,
527 &groups, &num_groups);
528 if (ret)
529 seq_printf(s, "function %s: COULD NOT GET GROUPS\n",
530 func);
531
532 seq_printf(s, "function: %s, groups = [ ", func);
533 for (i = 0; i < num_groups; i++)
534 seq_printf(s, "%s ", groups[i]);
535 seq_puts(s, "]\n");
536
537 func_selector++;
538 }
539
540 mutex_unlock(&pinctrl_mutex);
541
542 return 0;
543}
544
545static int pinmux_pins_show(struct seq_file *s, void *what)
546{
547 struct pinctrl_dev *pctldev = s->private;
548 const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
549 const struct pinmux_ops *pmxops = pctldev->desc->pmxops;
550 unsigned i, pin;
551
552 if (!pmxops)
553 return 0;
554
555 seq_puts(s, "Pinmux settings per pin\n");
556 seq_puts(s, "Format: pin (name): mux_owner gpio_owner hog?\n");
557
558 mutex_lock(&pinctrl_mutex);
559
560 /* The pin number can be retrived from the pin controller descriptor */
561 for (i = 0; i < pctldev->desc->npins; i++) {
562 struct pin_desc *desc;
563 bool is_hog = false;
564
565 pin = pctldev->desc->pins[i].number;
566 desc = pin_desc_get(pctldev, pin);
567 /* Skip if we cannot search the pin */
568 if (desc == NULL)
569 continue;
570
571 if (desc->mux_owner &&
572 !strcmp(desc->mux_owner, pinctrl_dev_get_name(pctldev)))
573 is_hog = true;
574
575 seq_printf(s, "pin %d (%s): %s %s%s", pin,
576 desc->name ? desc->name : "unnamed",
577 desc->mux_owner ? desc->mux_owner
578 : "(MUX UNCLAIMED)",
579 desc->gpio_owner ? desc->gpio_owner
580 : "(GPIO UNCLAIMED)",
581 is_hog ? " (HOG)" : "");
582
583 if (desc->mux_setting)
584 seq_printf(s, " function %s group %s\n",
585 pmxops->get_function_name(pctldev,
586 desc->mux_setting->func),
587 pctlops->get_group_name(pctldev,
588 desc->mux_setting->group));
589 else
590 seq_printf(s, "\n");
591 }
592
593 mutex_unlock(&pinctrl_mutex);
594
595 return 0;
596}
597
598void pinmux_show_map(struct seq_file *s, struct pinctrl_map const *map)
599{
600 seq_printf(s, "group %s\nfunction %s\n",
601 map->data.mux.group ? map->data.mux.group : "(default)",
602 map->data.mux.function);
603}
604
605void pinmux_show_setting(struct seq_file *s,
606 struct pinctrl_setting const *setting)
607{
608 struct pinctrl_dev *pctldev = setting->pctldev;
609 const struct pinmux_ops *pmxops = pctldev->desc->pmxops;
610 const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
611
612 seq_printf(s, "group: %s (%u) function: %s (%u)\n",
613 pctlops->get_group_name(pctldev, setting->data.mux.group),
614 setting->data.mux.group,
615 pmxops->get_function_name(pctldev, setting->data.mux.func),
616 setting->data.mux.func);
617}
618
619static int pinmux_functions_open(struct inode *inode, struct file *file)
620{
621 return single_open(file, pinmux_functions_show, inode->i_private);
622}
623
624static int pinmux_pins_open(struct inode *inode, struct file *file)
625{
626 return single_open(file, pinmux_pins_show, inode->i_private);
627}
628
629static const struct file_operations pinmux_functions_ops = {
630 .open = pinmux_functions_open,
631 .read = seq_read,
632 .llseek = seq_lseek,
633 .release = single_release,
634};
635
636static const struct file_operations pinmux_pins_ops = {
637 .open = pinmux_pins_open,
638 .read = seq_read,
639 .llseek = seq_lseek,
640 .release = single_release,
641};
642
643void pinmux_init_device_debugfs(struct dentry *devroot,
644 struct pinctrl_dev *pctldev)
645{
646 debugfs_create_file("pinmux-functions", S_IFREG | S_IRUGO,
647 devroot, pctldev, &pinmux_functions_ops);
648 debugfs_create_file("pinmux-pins", S_IFREG | S_IRUGO,
649 devroot, pctldev, &pinmux_pins_ops);
650}
651
652#endif /* CONFIG_DEBUG_FS */