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10#define pr_fmt(fmt) "mux-core: " fmt
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12#include <linux/device.h>
13#include <linux/err.h>
14#include <linux/export.h>
15#include <linux/idr.h>
16#include <linux/init.h>
17#include <linux/module.h>
18#include <linux/mux/consumer.h>
19#include <linux/mux/driver.h>
20#include <linux/of.h>
21#include <linux/of_platform.h>
22#include <linux/slab.h>
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28
29#define MUX_CACHE_UNKNOWN MUX_IDLE_AS_IS
30
31static struct class mux_class = {
32 .name = "mux",
33 .owner = THIS_MODULE,
34};
35
36static DEFINE_IDA(mux_ida);
37
38static int __init mux_init(void)
39{
40 ida_init(&mux_ida);
41 return class_register(&mux_class);
42}
43
44static void __exit mux_exit(void)
45{
46 class_unregister(&mux_class);
47 ida_destroy(&mux_ida);
48}
49
50static void mux_chip_release(struct device *dev)
51{
52 struct mux_chip *mux_chip = to_mux_chip(dev);
53
54 ida_simple_remove(&mux_ida, mux_chip->id);
55 kfree(mux_chip);
56}
57
58static const struct device_type mux_type = {
59 .name = "mux-chip",
60 .release = mux_chip_release,
61};
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79struct mux_chip *mux_chip_alloc(struct device *dev,
80 unsigned int controllers, size_t sizeof_priv)
81{
82 struct mux_chip *mux_chip;
83 int i;
84
85 if (WARN_ON(!dev || !controllers))
86 return ERR_PTR(-EINVAL);
87
88 mux_chip = kzalloc(sizeof(*mux_chip) +
89 controllers * sizeof(*mux_chip->mux) +
90 sizeof_priv, GFP_KERNEL);
91 if (!mux_chip)
92 return ERR_PTR(-ENOMEM);
93
94 mux_chip->mux = (struct mux_control *)(mux_chip + 1);
95 mux_chip->dev.class = &mux_class;
96 mux_chip->dev.type = &mux_type;
97 mux_chip->dev.parent = dev;
98 mux_chip->dev.of_node = dev->of_node;
99 dev_set_drvdata(&mux_chip->dev, mux_chip);
100
101 mux_chip->id = ida_simple_get(&mux_ida, 0, 0, GFP_KERNEL);
102 if (mux_chip->id < 0) {
103 int err = mux_chip->id;
104
105 pr_err("muxchipX failed to get a device id\n");
106 kfree(mux_chip);
107 return ERR_PTR(err);
108 }
109 dev_set_name(&mux_chip->dev, "muxchip%d", mux_chip->id);
110
111 mux_chip->controllers = controllers;
112 for (i = 0; i < controllers; ++i) {
113 struct mux_control *mux = &mux_chip->mux[i];
114
115 mux->chip = mux_chip;
116 sema_init(&mux->lock, 1);
117 mux->cached_state = MUX_CACHE_UNKNOWN;
118 mux->idle_state = MUX_IDLE_AS_IS;
119 }
120
121 device_initialize(&mux_chip->dev);
122
123 return mux_chip;
124}
125EXPORT_SYMBOL_GPL(mux_chip_alloc);
126
127static int mux_control_set(struct mux_control *mux, int state)
128{
129 int ret = mux->chip->ops->set(mux, state);
130
131 mux->cached_state = ret < 0 ? MUX_CACHE_UNKNOWN : state;
132
133 return ret;
134}
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146
147int mux_chip_register(struct mux_chip *mux_chip)
148{
149 int i;
150 int ret;
151
152 for (i = 0; i < mux_chip->controllers; ++i) {
153 struct mux_control *mux = &mux_chip->mux[i];
154
155 if (mux->idle_state == mux->cached_state)
156 continue;
157
158 ret = mux_control_set(mux, mux->idle_state);
159 if (ret < 0) {
160 dev_err(&mux_chip->dev, "unable to set idle state\n");
161 return ret;
162 }
163 }
164
165 ret = device_add(&mux_chip->dev);
166 if (ret < 0)
167 dev_err(&mux_chip->dev,
168 "device_add failed in %s: %d\n", __func__, ret);
169 return ret;
170}
171EXPORT_SYMBOL_GPL(mux_chip_register);
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180
181void mux_chip_unregister(struct mux_chip *mux_chip)
182{
183 device_del(&mux_chip->dev);
184}
185EXPORT_SYMBOL_GPL(mux_chip_unregister);
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192
193void mux_chip_free(struct mux_chip *mux_chip)
194{
195 if (!mux_chip)
196 return;
197
198 put_device(&mux_chip->dev);
199}
200EXPORT_SYMBOL_GPL(mux_chip_free);
201
202static void devm_mux_chip_release(struct device *dev, void *res)
203{
204 struct mux_chip *mux_chip = *(struct mux_chip **)res;
205
206 mux_chip_free(mux_chip);
207}
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219struct mux_chip *devm_mux_chip_alloc(struct device *dev,
220 unsigned int controllers,
221 size_t sizeof_priv)
222{
223 struct mux_chip **ptr, *mux_chip;
224
225 ptr = devres_alloc(devm_mux_chip_release, sizeof(*ptr), GFP_KERNEL);
226 if (!ptr)
227 return ERR_PTR(-ENOMEM);
228
229 mux_chip = mux_chip_alloc(dev, controllers, sizeof_priv);
230 if (IS_ERR(mux_chip)) {
231 devres_free(ptr);
232 return mux_chip;
233 }
234
235 *ptr = mux_chip;
236 devres_add(dev, ptr);
237
238 return mux_chip;
239}
240EXPORT_SYMBOL_GPL(devm_mux_chip_alloc);
241
242static void devm_mux_chip_reg_release(struct device *dev, void *res)
243{
244 struct mux_chip *mux_chip = *(struct mux_chip **)res;
245
246 mux_chip_unregister(mux_chip);
247}
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258int devm_mux_chip_register(struct device *dev,
259 struct mux_chip *mux_chip)
260{
261 struct mux_chip **ptr;
262 int res;
263
264 ptr = devres_alloc(devm_mux_chip_reg_release, sizeof(*ptr), GFP_KERNEL);
265 if (!ptr)
266 return -ENOMEM;
267
268 res = mux_chip_register(mux_chip);
269 if (res) {
270 devres_free(ptr);
271 return res;
272 }
273
274 *ptr = mux_chip;
275 devres_add(dev, ptr);
276
277 return res;
278}
279EXPORT_SYMBOL_GPL(devm_mux_chip_register);
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287unsigned int mux_control_states(struct mux_control *mux)
288{
289 return mux->states;
290}
291EXPORT_SYMBOL_GPL(mux_control_states);
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296static int __mux_control_select(struct mux_control *mux, int state)
297{
298 int ret;
299
300 if (WARN_ON(state < 0 || state >= mux->states))
301 return -EINVAL;
302
303 if (mux->cached_state == state)
304 return 0;
305
306 ret = mux_control_set(mux, state);
307 if (ret >= 0)
308 return 0;
309
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311 if (mux->idle_state != MUX_IDLE_AS_IS)
312 mux_control_set(mux, mux->idle_state);
313
314 return ret;
315}
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334int mux_control_select(struct mux_control *mux, unsigned int state)
335{
336 int ret;
337
338 ret = down_killable(&mux->lock);
339 if (ret < 0)
340 return ret;
341
342 ret = __mux_control_select(mux, state);
343
344 if (ret < 0)
345 up(&mux->lock);
346
347 return ret;
348}
349EXPORT_SYMBOL_GPL(mux_control_select);
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366int mux_control_try_select(struct mux_control *mux, unsigned int state)
367{
368 int ret;
369
370 if (down_trylock(&mux->lock))
371 return -EBUSY;
372
373 ret = __mux_control_select(mux, state);
374
375 if (ret < 0)
376 up(&mux->lock);
377
378 return ret;
379}
380EXPORT_SYMBOL_GPL(mux_control_try_select);
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394int mux_control_deselect(struct mux_control *mux)
395{
396 int ret = 0;
397
398 if (mux->idle_state != MUX_IDLE_AS_IS &&
399 mux->idle_state != mux->cached_state)
400 ret = mux_control_set(mux, mux->idle_state);
401
402 up(&mux->lock);
403
404 return ret;
405}
406EXPORT_SYMBOL_GPL(mux_control_deselect);
407
408static int of_dev_node_match(struct device *dev, const void *data)
409{
410 return dev->of_node == data;
411}
412
413
414static struct mux_chip *of_find_mux_chip_by_node(struct device_node *np)
415{
416 struct device *dev;
417
418 dev = class_find_device(&mux_class, NULL, np, of_dev_node_match);
419
420 return dev ? to_mux_chip(dev) : NULL;
421}
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430struct mux_control *mux_control_get(struct device *dev, const char *mux_name)
431{
432 struct device_node *np = dev->of_node;
433 struct of_phandle_args args;
434 struct mux_chip *mux_chip;
435 unsigned int controller;
436 int index = 0;
437 int ret;
438
439 if (mux_name) {
440 index = of_property_match_string(np, "mux-control-names",
441 mux_name);
442 if (index < 0) {
443 dev_err(dev, "mux controller '%s' not found\n",
444 mux_name);
445 return ERR_PTR(index);
446 }
447 }
448
449 ret = of_parse_phandle_with_args(np,
450 "mux-controls", "#mux-control-cells",
451 index, &args);
452 if (ret) {
453 dev_err(dev, "%pOF: failed to get mux-control %s(%i)\n",
454 np, mux_name ?: "", index);
455 return ERR_PTR(ret);
456 }
457
458 mux_chip = of_find_mux_chip_by_node(args.np);
459 of_node_put(args.np);
460 if (!mux_chip)
461 return ERR_PTR(-EPROBE_DEFER);
462
463 if (args.args_count > 1 ||
464 (!args.args_count && (mux_chip->controllers > 1))) {
465 dev_err(dev, "%pOF: wrong #mux-control-cells for %pOF\n",
466 np, args.np);
467 put_device(&mux_chip->dev);
468 return ERR_PTR(-EINVAL);
469 }
470
471 controller = 0;
472 if (args.args_count)
473 controller = args.args[0];
474
475 if (controller >= mux_chip->controllers) {
476 dev_err(dev, "%pOF: bad mux controller %u specified in %pOF\n",
477 np, controller, args.np);
478 put_device(&mux_chip->dev);
479 return ERR_PTR(-EINVAL);
480 }
481
482 return &mux_chip->mux[controller];
483}
484EXPORT_SYMBOL_GPL(mux_control_get);
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492void mux_control_put(struct mux_control *mux)
493{
494 put_device(&mux->chip->dev);
495}
496EXPORT_SYMBOL_GPL(mux_control_put);
497
498static void devm_mux_control_release(struct device *dev, void *res)
499{
500 struct mux_control *mux = *(struct mux_control **)res;
501
502 mux_control_put(mux);
503}
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513struct mux_control *devm_mux_control_get(struct device *dev,
514 const char *mux_name)
515{
516 struct mux_control **ptr, *mux;
517
518 ptr = devres_alloc(devm_mux_control_release, sizeof(*ptr), GFP_KERNEL);
519 if (!ptr)
520 return ERR_PTR(-ENOMEM);
521
522 mux = mux_control_get(dev, mux_name);
523 if (IS_ERR(mux)) {
524 devres_free(ptr);
525 return mux;
526 }
527
528 *ptr = mux;
529 devres_add(dev, ptr);
530
531 return mux;
532}
533EXPORT_SYMBOL_GPL(devm_mux_control_get);
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540
541subsys_initcall(mux_init);
542module_exit(mux_exit);
543
544MODULE_DESCRIPTION("Multiplexer subsystem");
545MODULE_AUTHOR("Peter Rosin <peda@axentia.se>");
546MODULE_LICENSE("GPL v2");
547