1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Arche Platform driver to enable Unipro link.
4 *
5 * Copyright 2014-2015 Google Inc.
6 * Copyright 2014-2015 Linaro Ltd.
7 */
8
9#include <linux/clk.h>
10#include <linux/delay.h>
11#include <linux/gpio/consumer.h>
12#include <linux/init.h>
13#include <linux/module.h>
14#include <linux/of_platform.h>
15#include <linux/pinctrl/consumer.h>
16#include <linux/platform_device.h>
17#include <linux/pm.h>
18#include <linux/interrupt.h>
19#include <linux/irq.h>
20#include <linux/suspend.h>
21#include <linux/time.h>
22#include <linux/greybus.h>
23#include <linux/of.h>
24#include "arche_platform.h"
25
26#if IS_ENABLED(CONFIG_USB_HSIC_USB3613)
27#include <linux/usb/usb3613.h>
28#else
29static inline int usb3613_hub_mode_ctrl(bool unused)
30{
31 return 0;
32}
33#endif
34
35#define WD_COLDBOOT_PULSE_WIDTH_MS 30
36
37enum svc_wakedetect_state {
38 WD_STATE_IDLE, /* Default state = pulled high/low */
39 WD_STATE_BOOT_INIT, /* WD = falling edge (low) */
40 WD_STATE_COLDBOOT_TRIG, /* WD = rising edge (high), > 30msec */
41 WD_STATE_STANDBYBOOT_TRIG, /* As of now not used ?? */
42 WD_STATE_COLDBOOT_START, /* Cold boot process started */
43 WD_STATE_STANDBYBOOT_START, /* Not used */
44};
45
46struct arche_platform_drvdata {
47 /* Control GPIO signals to and from AP <=> SVC */
48 struct gpio_desc *svc_reset;
49 bool is_reset_act_hi;
50 struct gpio_desc *svc_sysboot;
51 struct gpio_desc *wake_detect; /* bi-dir,maps to WAKE_MOD & WAKE_FRAME signals */
52
53 enum arche_platform_state state;
54
55 struct gpio_desc *svc_refclk_req;
56 struct clk *svc_ref_clk;
57
58 struct pinctrl *pinctrl;
59 struct pinctrl_state *pin_default;
60
61 int num_apbs;
62
63 enum svc_wakedetect_state wake_detect_state;
64 int wake_detect_irq;
65 spinlock_t wake_lock; /* Protect wake_detect_state */
66 struct mutex platform_state_mutex; /* Protect state */
67 unsigned long wake_detect_start;
68 struct notifier_block pm_notifier;
69
70 struct device *dev;
71};
72
73/* Requires calling context to hold arche_pdata->platform_state_mutex */
74static void arche_platform_set_state(struct arche_platform_drvdata *arche_pdata,
75 enum arche_platform_state state)
76{
77 arche_pdata->state = state;
78}
79
80/* Requires arche_pdata->wake_lock is held by calling context */
81static void arche_platform_set_wake_detect_state(struct arche_platform_drvdata *arche_pdata,
82 enum svc_wakedetect_state state)
83{
84 arche_pdata->wake_detect_state = state;
85}
86
87static inline void svc_reset_onoff(struct gpio_desc *gpio, bool onoff)
88{
89 gpiod_set_raw_value(desc: gpio, value: onoff);
90}
91
92static int apb_cold_boot(struct device *dev, void *data)
93{
94 int ret;
95
96 ret = apb_ctrl_coldboot(dev);
97 if (ret)
98 dev_warn(dev, "failed to coldboot\n");
99
100 /*Child nodes are independent, so do not exit coldboot operation */
101 return 0;
102}
103
104static int apb_poweroff(struct device *dev, void *data)
105{
106 apb_ctrl_poweroff(dev);
107
108 /* Enable HUB3613 into HUB mode. */
109 if (usb3613_hub_mode_ctrl(unused: false))
110 dev_warn(dev, "failed to control hub device\n");
111
112 return 0;
113}
114
115static void arche_platform_wd_irq_en(struct arche_platform_drvdata *arche_pdata)
116{
117 /* Enable interrupt here, to read event back from SVC */
118 enable_irq(irq: arche_pdata->wake_detect_irq);
119}
120
121static irqreturn_t arche_platform_wd_irq_thread(int irq, void *devid)
122{
123 struct arche_platform_drvdata *arche_pdata = devid;
124 unsigned long flags;
125
126 spin_lock_irqsave(&arche_pdata->wake_lock, flags);
127 if (arche_pdata->wake_detect_state != WD_STATE_COLDBOOT_TRIG) {
128 /* Something is wrong */
129 spin_unlock_irqrestore(lock: &arche_pdata->wake_lock, flags);
130 return IRQ_HANDLED;
131 }
132
133 arche_platform_set_wake_detect_state(arche_pdata,
134 state: WD_STATE_COLDBOOT_START);
135 spin_unlock_irqrestore(lock: &arche_pdata->wake_lock, flags);
136
137 /* It should complete power cycle, so first make sure it is poweroff */
138 device_for_each_child(dev: arche_pdata->dev, NULL, fn: apb_poweroff);
139
140 /* Bring APB out of reset: cold boot sequence */
141 device_for_each_child(dev: arche_pdata->dev, NULL, fn: apb_cold_boot);
142
143 /* Enable HUB3613 into HUB mode. */
144 if (usb3613_hub_mode_ctrl(unused: true))
145 dev_warn(arche_pdata->dev, "failed to control hub device\n");
146
147 spin_lock_irqsave(&arche_pdata->wake_lock, flags);
148 arche_platform_set_wake_detect_state(arche_pdata, state: WD_STATE_IDLE);
149 spin_unlock_irqrestore(lock: &arche_pdata->wake_lock, flags);
150
151 return IRQ_HANDLED;
152}
153
154static irqreturn_t arche_platform_wd_irq(int irq, void *devid)
155{
156 struct arche_platform_drvdata *arche_pdata = devid;
157 unsigned long flags;
158
159 spin_lock_irqsave(&arche_pdata->wake_lock, flags);
160
161 if (gpiod_get_value(desc: arche_pdata->wake_detect)) {
162 /* wake/detect rising */
163
164 /*
165 * If wake/detect line goes high after low, within less than
166 * 30msec, then standby boot sequence is initiated, which is not
167 * supported/implemented as of now. So ignore it.
168 */
169 if (arche_pdata->wake_detect_state == WD_STATE_BOOT_INIT) {
170 if (time_before(jiffies,
171 arche_pdata->wake_detect_start +
172 msecs_to_jiffies(WD_COLDBOOT_PULSE_WIDTH_MS))) {
173 arche_platform_set_wake_detect_state(arche_pdata,
174 state: WD_STATE_IDLE);
175 } else {
176 /*
177 * Check we are not in middle of irq thread
178 * already
179 */
180 if (arche_pdata->wake_detect_state !=
181 WD_STATE_COLDBOOT_START) {
182 arche_platform_set_wake_detect_state(arche_pdata,
183 state: WD_STATE_COLDBOOT_TRIG);
184 spin_unlock_irqrestore(lock: &arche_pdata->wake_lock,
185 flags);
186 return IRQ_WAKE_THREAD;
187 }
188 }
189 }
190 } else {
191 /* wake/detect falling */
192 if (arche_pdata->wake_detect_state == WD_STATE_IDLE) {
193 arche_pdata->wake_detect_start = jiffies;
194 /*
195 * In the beginning, when wake/detect goes low
196 * (first time), we assume it is meant for coldboot
197 * and set the flag. If wake/detect line stays low
198 * beyond 30msec, then it is coldboot else fallback
199 * to standby boot.
200 */
201 arche_platform_set_wake_detect_state(arche_pdata,
202 state: WD_STATE_BOOT_INIT);
203 }
204 }
205
206 spin_unlock_irqrestore(lock: &arche_pdata->wake_lock, flags);
207
208 return IRQ_HANDLED;
209}
210
211/*
212 * Requires arche_pdata->platform_state_mutex to be held
213 */
214static int
215arche_platform_coldboot_seq(struct arche_platform_drvdata *arche_pdata)
216{
217 int ret;
218
219 if (arche_pdata->state == ARCHE_PLATFORM_STATE_ACTIVE)
220 return 0;
221
222 dev_info(arche_pdata->dev, "Booting from cold boot state\n");
223
224 svc_reset_onoff(gpio: arche_pdata->svc_reset, onoff: arche_pdata->is_reset_act_hi);
225
226 gpiod_set_value(desc: arche_pdata->svc_sysboot, value: 0);
227 usleep_range(min: 100, max: 200);
228
229 ret = clk_prepare_enable(clk: arche_pdata->svc_ref_clk);
230 if (ret) {
231 dev_err(arche_pdata->dev, "failed to enable svc_ref_clk: %d\n",
232 ret);
233 return ret;
234 }
235
236 /* bring SVC out of reset */
237 svc_reset_onoff(gpio: arche_pdata->svc_reset, onoff: !arche_pdata->is_reset_act_hi);
238
239 arche_platform_set_state(arche_pdata, state: ARCHE_PLATFORM_STATE_ACTIVE);
240
241 return 0;
242}
243
244/*
245 * Requires arche_pdata->platform_state_mutex to be held
246 */
247static int
248arche_platform_fw_flashing_seq(struct arche_platform_drvdata *arche_pdata)
249{
250 int ret;
251
252 if (arche_pdata->state == ARCHE_PLATFORM_STATE_FW_FLASHING)
253 return 0;
254
255 dev_info(arche_pdata->dev, "Switching to FW flashing state\n");
256
257 svc_reset_onoff(gpio: arche_pdata->svc_reset, onoff: arche_pdata->is_reset_act_hi);
258
259 gpiod_set_value(desc: arche_pdata->svc_sysboot, value: 1);
260
261 usleep_range(min: 100, max: 200);
262
263 ret = clk_prepare_enable(clk: arche_pdata->svc_ref_clk);
264 if (ret) {
265 dev_err(arche_pdata->dev, "failed to enable svc_ref_clk: %d\n",
266 ret);
267 return ret;
268 }
269
270 svc_reset_onoff(gpio: arche_pdata->svc_reset, onoff: !arche_pdata->is_reset_act_hi);
271
272 arche_platform_set_state(arche_pdata, state: ARCHE_PLATFORM_STATE_FW_FLASHING);
273
274 return 0;
275}
276
277/*
278 * Requires arche_pdata->platform_state_mutex to be held
279 */
280static void
281arche_platform_poweroff_seq(struct arche_platform_drvdata *arche_pdata)
282{
283 unsigned long flags;
284
285 if (arche_pdata->state == ARCHE_PLATFORM_STATE_OFF)
286 return;
287
288 /* If in fw_flashing mode, then no need to repeate things again */
289 if (arche_pdata->state != ARCHE_PLATFORM_STATE_FW_FLASHING) {
290 disable_irq(irq: arche_pdata->wake_detect_irq);
291
292 spin_lock_irqsave(&arche_pdata->wake_lock, flags);
293 arche_platform_set_wake_detect_state(arche_pdata,
294 state: WD_STATE_IDLE);
295 spin_unlock_irqrestore(lock: &arche_pdata->wake_lock, flags);
296 }
297
298 clk_disable_unprepare(clk: arche_pdata->svc_ref_clk);
299
300 /* As part of exit, put APB back in reset state */
301 svc_reset_onoff(gpio: arche_pdata->svc_reset, onoff: arche_pdata->is_reset_act_hi);
302
303 arche_platform_set_state(arche_pdata, state: ARCHE_PLATFORM_STATE_OFF);
304}
305
306static ssize_t state_store(struct device *dev,
307 struct device_attribute *attr,
308 const char *buf, size_t count)
309{
310 struct arche_platform_drvdata *arche_pdata = dev_get_drvdata(dev);
311 int ret = 0;
312
313 mutex_lock(&arche_pdata->platform_state_mutex);
314
315 if (sysfs_streq(s1: buf, s2: "off")) {
316 if (arche_pdata->state == ARCHE_PLATFORM_STATE_OFF)
317 goto exit;
318
319 /* If SVC goes down, bring down APB's as well */
320 device_for_each_child(dev: arche_pdata->dev, NULL, fn: apb_poweroff);
321
322 arche_platform_poweroff_seq(arche_pdata);
323
324 } else if (sysfs_streq(s1: buf, s2: "active")) {
325 if (arche_pdata->state == ARCHE_PLATFORM_STATE_ACTIVE)
326 goto exit;
327
328 /* First we want to make sure we power off everything
329 * and then activate back again
330 */
331 device_for_each_child(dev: arche_pdata->dev, NULL, fn: apb_poweroff);
332 arche_platform_poweroff_seq(arche_pdata);
333
334 arche_platform_wd_irq_en(arche_pdata);
335 ret = arche_platform_coldboot_seq(arche_pdata);
336 if (ret)
337 goto exit;
338
339 } else if (sysfs_streq(s1: buf, s2: "standby")) {
340 if (arche_pdata->state == ARCHE_PLATFORM_STATE_STANDBY)
341 goto exit;
342
343 dev_warn(arche_pdata->dev, "standby state not supported\n");
344 } else if (sysfs_streq(s1: buf, s2: "fw_flashing")) {
345 if (arche_pdata->state == ARCHE_PLATFORM_STATE_FW_FLASHING)
346 goto exit;
347
348 /*
349 * Here we only control SVC.
350 *
351 * In case of FW_FLASHING mode we do not want to control
352 * APBs, as in case of V2, SPI bus is shared between both
353 * the APBs. So let user chose which APB he wants to flash.
354 */
355 arche_platform_poweroff_seq(arche_pdata);
356
357 ret = arche_platform_fw_flashing_seq(arche_pdata);
358 if (ret)
359 goto exit;
360 } else {
361 dev_err(arche_pdata->dev, "unknown state\n");
362 ret = -EINVAL;
363 }
364
365exit:
366 mutex_unlock(lock: &arche_pdata->platform_state_mutex);
367 return ret ? ret : count;
368}
369
370static ssize_t state_show(struct device *dev,
371 struct device_attribute *attr, char *buf)
372{
373 struct arche_platform_drvdata *arche_pdata = dev_get_drvdata(dev);
374
375 switch (arche_pdata->state) {
376 case ARCHE_PLATFORM_STATE_OFF:
377 return sprintf(buf, fmt: "off\n");
378 case ARCHE_PLATFORM_STATE_ACTIVE:
379 return sprintf(buf, fmt: "active\n");
380 case ARCHE_PLATFORM_STATE_STANDBY:
381 return sprintf(buf, fmt: "standby\n");
382 case ARCHE_PLATFORM_STATE_FW_FLASHING:
383 return sprintf(buf, fmt: "fw_flashing\n");
384 default:
385 return sprintf(buf, fmt: "unknown state\n");
386 }
387}
388
389static DEVICE_ATTR_RW(state);
390
391static int arche_platform_pm_notifier(struct notifier_block *notifier,
392 unsigned long pm_event, void *unused)
393{
394 struct arche_platform_drvdata *arche_pdata =
395 container_of(notifier, struct arche_platform_drvdata,
396 pm_notifier);
397 int ret = NOTIFY_DONE;
398
399 mutex_lock(&arche_pdata->platform_state_mutex);
400 switch (pm_event) {
401 case PM_SUSPEND_PREPARE:
402 if (arche_pdata->state != ARCHE_PLATFORM_STATE_ACTIVE) {
403 ret = NOTIFY_STOP;
404 break;
405 }
406 device_for_each_child(dev: arche_pdata->dev, NULL, fn: apb_poweroff);
407 arche_platform_poweroff_seq(arche_pdata);
408 break;
409 case PM_POST_SUSPEND:
410 if (arche_pdata->state != ARCHE_PLATFORM_STATE_OFF)
411 break;
412
413 arche_platform_wd_irq_en(arche_pdata);
414 arche_platform_coldboot_seq(arche_pdata);
415 break;
416 default:
417 break;
418 }
419 mutex_unlock(lock: &arche_pdata->platform_state_mutex);
420
421 return ret;
422}
423
424static int arche_platform_probe(struct platform_device *pdev)
425{
426 struct arche_platform_drvdata *arche_pdata;
427 struct device *dev = &pdev->dev;
428 struct device_node *np = dev->of_node;
429 int ret;
430 unsigned int flags;
431
432 arche_pdata = devm_kzalloc(dev: &pdev->dev, size: sizeof(*arche_pdata),
433 GFP_KERNEL);
434 if (!arche_pdata)
435 return -ENOMEM;
436
437 /* setup svc reset gpio */
438 arche_pdata->is_reset_act_hi = of_property_read_bool(np,
439 propname: "svc,reset-active-high");
440 if (arche_pdata->is_reset_act_hi)
441 flags = GPIOD_OUT_HIGH;
442 else
443 flags = GPIOD_OUT_LOW;
444
445 arche_pdata->svc_reset = devm_gpiod_get(dev, con_id: "svc,reset", flags);
446 if (IS_ERR(ptr: arche_pdata->svc_reset)) {
447 ret = PTR_ERR(ptr: arche_pdata->svc_reset);
448 dev_err(dev, "failed to request svc-reset GPIO: %d\n", ret);
449 return ret;
450 }
451 arche_platform_set_state(arche_pdata, state: ARCHE_PLATFORM_STATE_OFF);
452
453 arche_pdata->svc_sysboot = devm_gpiod_get(dev, con_id: "svc,sysboot",
454 flags: GPIOD_OUT_LOW);
455 if (IS_ERR(ptr: arche_pdata->svc_sysboot)) {
456 ret = PTR_ERR(ptr: arche_pdata->svc_sysboot);
457 dev_err(dev, "failed to request sysboot0 GPIO: %d\n", ret);
458 return ret;
459 }
460
461 /* setup the clock request gpio first */
462 arche_pdata->svc_refclk_req = devm_gpiod_get(dev, con_id: "svc,refclk-req",
463 flags: GPIOD_IN);
464 if (IS_ERR(ptr: arche_pdata->svc_refclk_req)) {
465 ret = PTR_ERR(ptr: arche_pdata->svc_refclk_req);
466 dev_err(dev, "failed to request svc-clk-req GPIO: %d\n", ret);
467 return ret;
468 }
469
470 /* setup refclk2 to follow the pin */
471 arche_pdata->svc_ref_clk = devm_clk_get(dev, id: "svc_ref_clk");
472 if (IS_ERR(ptr: arche_pdata->svc_ref_clk)) {
473 ret = PTR_ERR(ptr: arche_pdata->svc_ref_clk);
474 dev_err(dev, "failed to get svc_ref_clk: %d\n", ret);
475 return ret;
476 }
477
478 platform_set_drvdata(pdev, data: arche_pdata);
479
480 arche_pdata->num_apbs = of_get_child_count(np);
481 dev_dbg(dev, "Number of APB's available - %d\n", arche_pdata->num_apbs);
482
483 arche_pdata->wake_detect = devm_gpiod_get(dev, con_id: "svc,wake-detect",
484 flags: GPIOD_IN);
485 if (IS_ERR(ptr: arche_pdata->wake_detect)) {
486 ret = PTR_ERR(ptr: arche_pdata->wake_detect);
487 dev_err(dev, "Failed requesting wake_detect GPIO: %d\n", ret);
488 return ret;
489 }
490
491 arche_platform_set_wake_detect_state(arche_pdata, state: WD_STATE_IDLE);
492
493 arche_pdata->dev = &pdev->dev;
494
495 spin_lock_init(&arche_pdata->wake_lock);
496 mutex_init(&arche_pdata->platform_state_mutex);
497 arche_pdata->wake_detect_irq =
498 gpiod_to_irq(desc: arche_pdata->wake_detect);
499
500 ret = devm_request_threaded_irq(dev, irq: arche_pdata->wake_detect_irq,
501 handler: arche_platform_wd_irq,
502 thread_fn: arche_platform_wd_irq_thread,
503 IRQF_TRIGGER_FALLING |
504 IRQF_TRIGGER_RISING | IRQF_ONESHOT,
505 devname: dev_name(dev), dev_id: arche_pdata);
506 if (ret) {
507 dev_err(dev, "failed to request wake detect IRQ %d\n", ret);
508 return ret;
509 }
510 disable_irq(irq: arche_pdata->wake_detect_irq);
511
512 ret = device_create_file(device: dev, entry: &dev_attr_state);
513 if (ret) {
514 dev_err(dev, "failed to create state file in sysfs\n");
515 return ret;
516 }
517
518 ret = of_platform_populate(root: np, NULL, NULL, parent: dev);
519 if (ret) {
520 dev_err(dev, "failed to populate child nodes %d\n", ret);
521 goto err_device_remove;
522 }
523
524 arche_pdata->pm_notifier.notifier_call = arche_platform_pm_notifier;
525 ret = register_pm_notifier(nb: &arche_pdata->pm_notifier);
526
527 if (ret) {
528 dev_err(dev, "failed to register pm notifier %d\n", ret);
529 goto err_device_remove;
530 }
531
532 /* Explicitly power off if requested */
533 if (!of_property_read_bool(np: pdev->dev.of_node, propname: "arche,init-off")) {
534 mutex_lock(&arche_pdata->platform_state_mutex);
535 ret = arche_platform_coldboot_seq(arche_pdata);
536 if (ret) {
537 dev_err(dev, "Failed to cold boot svc %d\n", ret);
538 goto err_coldboot;
539 }
540 arche_platform_wd_irq_en(arche_pdata);
541 mutex_unlock(lock: &arche_pdata->platform_state_mutex);
542 }
543
544 dev_info(dev, "Device registered successfully\n");
545 return 0;
546
547err_coldboot:
548 mutex_unlock(lock: &arche_pdata->platform_state_mutex);
549err_device_remove:
550 device_remove_file(dev: &pdev->dev, attr: &dev_attr_state);
551 return ret;
552}
553
554static int arche_remove_child(struct device *dev, void *unused)
555{
556 struct platform_device *pdev = to_platform_device(dev);
557
558 platform_device_unregister(pdev);
559
560 return 0;
561}
562
563static void arche_platform_remove(struct platform_device *pdev)
564{
565 struct arche_platform_drvdata *arche_pdata = platform_get_drvdata(pdev);
566
567 unregister_pm_notifier(nb: &arche_pdata->pm_notifier);
568 device_remove_file(dev: &pdev->dev, attr: &dev_attr_state);
569 device_for_each_child(dev: &pdev->dev, NULL, fn: arche_remove_child);
570 arche_platform_poweroff_seq(arche_pdata);
571
572 if (usb3613_hub_mode_ctrl(unused: false))
573 dev_warn(arche_pdata->dev, "failed to control hub device\n");
574}
575
576static __maybe_unused int arche_platform_suspend(struct device *dev)
577{
578 /*
579 * If timing profile premits, we may shutdown bridge
580 * completely
581 *
582 * TODO: sequence ??
583 *
584 * Also, need to make sure we meet precondition for unipro suspend
585 * Precondition: Definition ???
586 */
587 return 0;
588}
589
590static __maybe_unused int arche_platform_resume(struct device *dev)
591{
592 /*
593 * At least for ES2 we have to meet the delay requirement between
594 * unipro switch and AP bridge init, depending on whether bridge is in
595 * OFF state or standby state.
596 *
597 * Based on whether bridge is in standby or OFF state we may have to
598 * assert multiple signals. Please refer to WDM spec, for more info.
599 *
600 */
601 return 0;
602}
603
604static void arche_platform_shutdown(struct platform_device *pdev)
605{
606 struct arche_platform_drvdata *arche_pdata = platform_get_drvdata(pdev);
607
608 arche_platform_poweroff_seq(arche_pdata);
609
610 usb3613_hub_mode_ctrl(unused: false);
611}
612
613static SIMPLE_DEV_PM_OPS(arche_platform_pm_ops,
614 arche_platform_suspend,
615 arche_platform_resume);
616
617static const struct of_device_id arche_platform_of_match[] = {
618 /* Use PID/VID of SVC device */
619 { .compatible = "google,arche-platform", },
620 { },
621};
622
623static const struct of_device_id arche_combined_id[] = {
624 /* Use PID/VID of SVC device */
625 { .compatible = "google,arche-platform", },
626 { .compatible = "usbffff,2", },
627 { },
628};
629MODULE_DEVICE_TABLE(of, arche_combined_id);
630
631static struct platform_driver arche_platform_device_driver = {
632 .probe = arche_platform_probe,
633 .remove_new = arche_platform_remove,
634 .shutdown = arche_platform_shutdown,
635 .driver = {
636 .name = "arche-platform-ctrl",
637 .pm = &arche_platform_pm_ops,
638 .of_match_table = arche_platform_of_match,
639 }
640};
641
642static int __init arche_init(void)
643{
644 int retval;
645
646 retval = platform_driver_register(&arche_platform_device_driver);
647 if (retval)
648 return retval;
649
650 retval = arche_apb_init();
651 if (retval)
652 platform_driver_unregister(&arche_platform_device_driver);
653
654 return retval;
655}
656module_init(arche_init);
657
658static void __exit arche_exit(void)
659{
660 arche_apb_exit();
661 platform_driver_unregister(&arche_platform_device_driver);
662}
663module_exit(arche_exit);
664
665MODULE_LICENSE("GPL v2");
666MODULE_AUTHOR("Vaibhav Hiremath <vaibhav.hiremath@linaro.org>");
667MODULE_DESCRIPTION("Arche Platform Driver");
668

source code of linux/drivers/staging/greybus/arche-platform.c