Merge tag 'tag-chrome-platform-for-v5.2' of ssh://gitolite.kernel.org/pub/scm/linux...
[linux-2.6-microblaze.git] / drivers / staging / greybus / arche-platform.c
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 "arche_platform.h"
23 #include "greybus.h"
24
25 #if IS_ENABLED(CONFIG_USB_HSIC_USB3613)
26 #include <linux/usb/usb3613.h>
27 #else
28 static inline int usb3613_hub_mode_ctrl(bool unused)
29 {
30         return 0;
31 }
32 #endif
33
34 #define WD_COLDBOOT_PULSE_WIDTH_MS      30
35
36 enum svc_wakedetect_state {
37         WD_STATE_IDLE,                  /* Default state = pulled high/low */
38         WD_STATE_BOOT_INIT,             /* WD = falling edge (low) */
39         WD_STATE_COLDBOOT_TRIG,         /* WD = rising edge (high), > 30msec */
40         WD_STATE_STANDBYBOOT_TRIG,      /* As of now not used ?? */
41         WD_STATE_COLDBOOT_START,        /* Cold boot process started */
42         WD_STATE_STANDBYBOOT_START,     /* Not used */
43 };
44
45 struct arche_platform_drvdata {
46         /* Control GPIO signals to and from AP <=> SVC */
47         struct gpio_desc *svc_reset;
48         bool is_reset_act_hi;
49         struct gpio_desc *svc_sysboot;
50         struct gpio_desc *wake_detect; /* bi-dir,maps to WAKE_MOD & WAKE_FRAME signals */
51
52         enum arche_platform_state state;
53
54         struct gpio_desc *svc_refclk_req;
55         struct clk *svc_ref_clk;
56
57         struct pinctrl *pinctrl;
58         struct pinctrl_state *pin_default;
59
60         int num_apbs;
61
62         enum svc_wakedetect_state wake_detect_state;
63         int wake_detect_irq;
64         spinlock_t wake_lock;                   /* Protect wake_detect_state */
65         struct mutex platform_state_mutex;      /* Protect state */
66         unsigned long wake_detect_start;
67         struct notifier_block pm_notifier;
68
69         struct device *dev;
70 };
71
72 /* Requires calling context to hold arche_pdata->platform_state_mutex */
73 static void arche_platform_set_state(struct arche_platform_drvdata *arche_pdata,
74                                      enum arche_platform_state state)
75 {
76         arche_pdata->state = state;
77 }
78
79 /* Requires arche_pdata->wake_lock is held by calling context */
80 static void arche_platform_set_wake_detect_state(
81                                 struct arche_platform_drvdata *arche_pdata,
82                                 enum svc_wakedetect_state state)
83 {
84         arche_pdata->wake_detect_state = state;
85 }
86
87 static inline void svc_reset_onoff(struct gpio_desc *gpio, bool onoff)
88 {
89         gpiod_set_raw_value(gpio, onoff);
90 }
91
92 static 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
104 static 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(false))
110                 dev_warn(dev, "failed to control hub device\n");
111
112         return 0;
113 }
114
115 static 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(arche_pdata->wake_detect_irq);
119 }
120
121 static 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(&arche_pdata->wake_lock, flags);
130                 return IRQ_HANDLED;
131         }
132
133         arche_platform_set_wake_detect_state(arche_pdata,
134                                              WD_STATE_COLDBOOT_START);
135         spin_unlock_irqrestore(&arche_pdata->wake_lock, flags);
136
137         /* It should complete power cycle, so first make sure it is poweroff */
138         device_for_each_child(arche_pdata->dev, NULL, apb_poweroff);
139
140         /* Bring APB out of reset: cold boot sequence */
141         device_for_each_child(arche_pdata->dev, NULL, apb_cold_boot);
142
143         /* Enable HUB3613 into HUB mode. */
144         if (usb3613_hub_mode_ctrl(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, WD_STATE_IDLE);
149         spin_unlock_irqrestore(&arche_pdata->wake_lock, flags);
150
151         return IRQ_HANDLED;
152 }
153
154 static 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(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                                                                      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                                                                              WD_STATE_COLDBOOT_TRIG);
184                                         spin_unlock_irqrestore(
185                                                 &arche_pdata->wake_lock,
186                                                 flags);
187                                         return IRQ_WAKE_THREAD;
188                                 }
189                         }
190                 }
191         } else {
192                 /* wake/detect falling */
193                 if (arche_pdata->wake_detect_state == WD_STATE_IDLE) {
194                         arche_pdata->wake_detect_start = jiffies;
195                         /*
196                          * In the beginning, when wake/detect goes low
197                          * (first time), we assume it is meant for coldboot
198                          * and set the flag. If wake/detect line stays low
199                          * beyond 30msec, then it is coldboot else fallback
200                          * to standby boot.
201                          */
202                         arche_platform_set_wake_detect_state(arche_pdata,
203                                                              WD_STATE_BOOT_INIT);
204                 }
205         }
206
207         spin_unlock_irqrestore(&arche_pdata->wake_lock, flags);
208
209         return IRQ_HANDLED;
210 }
211
212 /*
213  * Requires arche_pdata->platform_state_mutex to be held
214  */
215 static int
216 arche_platform_coldboot_seq(struct arche_platform_drvdata *arche_pdata)
217 {
218         int ret;
219
220         if (arche_pdata->state == ARCHE_PLATFORM_STATE_ACTIVE)
221                 return 0;
222
223         dev_info(arche_pdata->dev, "Booting from cold boot state\n");
224
225         svc_reset_onoff(arche_pdata->svc_reset, arche_pdata->is_reset_act_hi);
226
227         gpiod_set_value(arche_pdata->svc_sysboot, 0);
228         usleep_range(100, 200);
229
230         ret = clk_prepare_enable(arche_pdata->svc_ref_clk);
231         if (ret) {
232                 dev_err(arche_pdata->dev, "failed to enable svc_ref_clk: %d\n",
233                         ret);
234                 return ret;
235         }
236
237         /* bring SVC out of reset */
238         svc_reset_onoff(arche_pdata->svc_reset, !arche_pdata->is_reset_act_hi);
239
240         arche_platform_set_state(arche_pdata, ARCHE_PLATFORM_STATE_ACTIVE);
241
242         return 0;
243 }
244
245 /*
246  * Requires arche_pdata->platform_state_mutex to be held
247  */
248 static int
249 arche_platform_fw_flashing_seq(struct arche_platform_drvdata *arche_pdata)
250 {
251         int ret;
252
253         if (arche_pdata->state == ARCHE_PLATFORM_STATE_FW_FLASHING)
254                 return 0;
255
256         dev_info(arche_pdata->dev, "Switching to FW flashing state\n");
257
258         svc_reset_onoff(arche_pdata->svc_reset, arche_pdata->is_reset_act_hi);
259
260         gpiod_set_value(arche_pdata->svc_sysboot, 1);
261
262         usleep_range(100, 200);
263
264         ret = clk_prepare_enable(arche_pdata->svc_ref_clk);
265         if (ret) {
266                 dev_err(arche_pdata->dev, "failed to enable svc_ref_clk: %d\n",
267                         ret);
268                 return ret;
269         }
270
271         svc_reset_onoff(arche_pdata->svc_reset, !arche_pdata->is_reset_act_hi);
272
273         arche_platform_set_state(arche_pdata, ARCHE_PLATFORM_STATE_FW_FLASHING);
274
275         return 0;
276 }
277
278 /*
279  * Requires arche_pdata->platform_state_mutex to be held
280  */
281 static void
282 arche_platform_poweroff_seq(struct arche_platform_drvdata *arche_pdata)
283 {
284         unsigned long flags;
285
286         if (arche_pdata->state == ARCHE_PLATFORM_STATE_OFF)
287                 return;
288
289         /* If in fw_flashing mode, then no need to repeate things again */
290         if (arche_pdata->state != ARCHE_PLATFORM_STATE_FW_FLASHING) {
291                 disable_irq(arche_pdata->wake_detect_irq);
292
293                 spin_lock_irqsave(&arche_pdata->wake_lock, flags);
294                 arche_platform_set_wake_detect_state(arche_pdata,
295                                                      WD_STATE_IDLE);
296                 spin_unlock_irqrestore(&arche_pdata->wake_lock, flags);
297         }
298
299         clk_disable_unprepare(arche_pdata->svc_ref_clk);
300
301         /* As part of exit, put APB back in reset state */
302         svc_reset_onoff(arche_pdata->svc_reset, arche_pdata->is_reset_act_hi);
303
304         arche_platform_set_state(arche_pdata, ARCHE_PLATFORM_STATE_OFF);
305 }
306
307 static ssize_t state_store(struct device *dev,
308                            struct device_attribute *attr,
309                            const char *buf, size_t count)
310 {
311         struct arche_platform_drvdata *arche_pdata = dev_get_drvdata(dev);
312         int ret = 0;
313
314         mutex_lock(&arche_pdata->platform_state_mutex);
315
316         if (sysfs_streq(buf, "off")) {
317                 if (arche_pdata->state == ARCHE_PLATFORM_STATE_OFF)
318                         goto exit;
319
320                 /*  If SVC goes down, bring down APB's as well */
321                 device_for_each_child(arche_pdata->dev, NULL, apb_poweroff);
322
323                 arche_platform_poweroff_seq(arche_pdata);
324
325         } else if (sysfs_streq(buf, "active")) {
326                 if (arche_pdata->state == ARCHE_PLATFORM_STATE_ACTIVE)
327                         goto exit;
328
329                 /* First we want to make sure we power off everything
330                  * and then activate back again
331                  */
332                 device_for_each_child(arche_pdata->dev, NULL, apb_poweroff);
333                 arche_platform_poweroff_seq(arche_pdata);
334
335                 arche_platform_wd_irq_en(arche_pdata);
336                 ret = arche_platform_coldboot_seq(arche_pdata);
337                 if (ret)
338                         goto exit;
339
340         } else if (sysfs_streq(buf, "standby")) {
341                 if (arche_pdata->state == ARCHE_PLATFORM_STATE_STANDBY)
342                         goto exit;
343
344                 dev_warn(arche_pdata->dev, "standby state not supported\n");
345         } else if (sysfs_streq(buf, "fw_flashing")) {
346                 if (arche_pdata->state == ARCHE_PLATFORM_STATE_FW_FLASHING)
347                         goto exit;
348
349                 /*
350                  * Here we only control SVC.
351                  *
352                  * In case of FW_FLASHING mode we do not want to control
353                  * APBs, as in case of V2, SPI bus is shared between both
354                  * the APBs. So let user chose which APB he wants to flash.
355                  */
356                 arche_platform_poweroff_seq(arche_pdata);
357
358                 ret = arche_platform_fw_flashing_seq(arche_pdata);
359                 if (ret)
360                         goto exit;
361         } else {
362                 dev_err(arche_pdata->dev, "unknown state\n");
363                 ret = -EINVAL;
364         }
365
366 exit:
367         mutex_unlock(&arche_pdata->platform_state_mutex);
368         return ret ? ret : count;
369 }
370
371 static ssize_t state_show(struct device *dev,
372                           struct device_attribute *attr, char *buf)
373 {
374         struct arche_platform_drvdata *arche_pdata = dev_get_drvdata(dev);
375
376         switch (arche_pdata->state) {
377         case ARCHE_PLATFORM_STATE_OFF:
378                 return sprintf(buf, "off\n");
379         case ARCHE_PLATFORM_STATE_ACTIVE:
380                 return sprintf(buf, "active\n");
381         case ARCHE_PLATFORM_STATE_STANDBY:
382                 return sprintf(buf, "standby\n");
383         case ARCHE_PLATFORM_STATE_FW_FLASHING:
384                 return sprintf(buf, "fw_flashing\n");
385         default:
386                 return sprintf(buf, "unknown state\n");
387         }
388 }
389
390 static DEVICE_ATTR_RW(state);
391
392 static int arche_platform_pm_notifier(struct notifier_block *notifier,
393                                       unsigned long pm_event, void *unused)
394 {
395         struct arche_platform_drvdata *arche_pdata =
396                 container_of(notifier, struct arche_platform_drvdata,
397                              pm_notifier);
398         int ret = NOTIFY_DONE;
399
400         mutex_lock(&arche_pdata->platform_state_mutex);
401         switch (pm_event) {
402         case PM_SUSPEND_PREPARE:
403                 if (arche_pdata->state != ARCHE_PLATFORM_STATE_ACTIVE) {
404                         ret = NOTIFY_STOP;
405                         break;
406                 }
407                 device_for_each_child(arche_pdata->dev, NULL, apb_poweroff);
408                 arche_platform_poweroff_seq(arche_pdata);
409                 break;
410         case PM_POST_SUSPEND:
411                 if (arche_pdata->state != ARCHE_PLATFORM_STATE_OFF)
412                         break;
413
414                 arche_platform_wd_irq_en(arche_pdata);
415                 arche_platform_coldboot_seq(arche_pdata);
416                 break;
417         default:
418                 break;
419         }
420         mutex_unlock(&arche_pdata->platform_state_mutex);
421
422         return ret;
423 }
424
425 static int arche_platform_probe(struct platform_device *pdev)
426 {
427         struct arche_platform_drvdata *arche_pdata;
428         struct device *dev = &pdev->dev;
429         struct device_node *np = dev->of_node;
430         int ret;
431         unsigned int flags;
432
433         arche_pdata = devm_kzalloc(&pdev->dev, sizeof(*arche_pdata),
434                                    GFP_KERNEL);
435         if (!arche_pdata)
436                 return -ENOMEM;
437
438         /* setup svc reset gpio */
439         arche_pdata->is_reset_act_hi = of_property_read_bool(np,
440                                                              "svc,reset-active-high");
441         if (arche_pdata->is_reset_act_hi)
442                 flags = GPIOD_OUT_HIGH;
443         else
444                 flags = GPIOD_OUT_LOW;
445
446         arche_pdata->svc_reset = devm_gpiod_get(dev, "svc,reset", flags);
447         if (IS_ERR(arche_pdata->svc_reset)) {
448                 ret = PTR_ERR(arche_pdata->svc_reset);
449                 dev_err(dev, "failed to request svc-reset GPIO: %d\n", ret);
450                 return ret;
451         }
452         arche_platform_set_state(arche_pdata, ARCHE_PLATFORM_STATE_OFF);
453
454         arche_pdata->svc_sysboot = devm_gpiod_get(dev, "svc,sysboot",
455                                                   GPIOD_OUT_LOW);
456         if (IS_ERR(arche_pdata->svc_sysboot)) {
457                 ret = PTR_ERR(arche_pdata->svc_sysboot);
458                 dev_err(dev, "failed to request sysboot0 GPIO: %d\n", ret);
459                 return ret;
460         }
461
462         /* setup the clock request gpio first */
463         arche_pdata->svc_refclk_req = devm_gpiod_get(dev, "svc,refclk-req",
464                                                      GPIOD_IN);
465         if (IS_ERR(arche_pdata->svc_refclk_req)) {
466                 ret = PTR_ERR(arche_pdata->svc_refclk_req);
467                 dev_err(dev, "failed to request svc-clk-req GPIO: %d\n", ret);
468                 return ret;
469         }
470
471         /* setup refclk2 to follow the pin */
472         arche_pdata->svc_ref_clk = devm_clk_get(dev, "svc_ref_clk");
473         if (IS_ERR(arche_pdata->svc_ref_clk)) {
474                 ret = PTR_ERR(arche_pdata->svc_ref_clk);
475                 dev_err(dev, "failed to get svc_ref_clk: %d\n", ret);
476                 return ret;
477         }
478
479         platform_set_drvdata(pdev, arche_pdata);
480
481         arche_pdata->num_apbs = of_get_child_count(np);
482         dev_dbg(dev, "Number of APB's available - %d\n", arche_pdata->num_apbs);
483
484         arche_pdata->wake_detect = devm_gpiod_get(dev, "svc,wake-detect",
485                                                   GPIOD_IN);
486         if (IS_ERR(arche_pdata->wake_detect)) {
487                 ret = PTR_ERR(arche_pdata->wake_detect);
488                 dev_err(dev, "Failed requesting wake_detect GPIO: %d\n", ret);
489                 return ret;
490         }
491
492         arche_platform_set_wake_detect_state(arche_pdata, WD_STATE_IDLE);
493
494         arche_pdata->dev = &pdev->dev;
495
496         spin_lock_init(&arche_pdata->wake_lock);
497         mutex_init(&arche_pdata->platform_state_mutex);
498         arche_pdata->wake_detect_irq =
499                 gpiod_to_irq(arche_pdata->wake_detect);
500
501         ret = devm_request_threaded_irq(dev, arche_pdata->wake_detect_irq,
502                                         arche_platform_wd_irq,
503                                         arche_platform_wd_irq_thread,
504                                         IRQF_TRIGGER_FALLING |
505                                         IRQF_TRIGGER_RISING | IRQF_ONESHOT,
506                                         dev_name(dev), arche_pdata);
507         if (ret) {
508                 dev_err(dev, "failed to request wake detect IRQ %d\n", ret);
509                 return ret;
510         }
511         disable_irq(arche_pdata->wake_detect_irq);
512
513         ret = device_create_file(dev, &dev_attr_state);
514         if (ret) {
515                 dev_err(dev, "failed to create state file in sysfs\n");
516                 return ret;
517         }
518
519         ret = of_platform_populate(np, NULL, NULL, dev);
520         if (ret) {
521                 dev_err(dev, "failed to populate child nodes %d\n", ret);
522                 goto err_device_remove;
523         }
524
525         arche_pdata->pm_notifier.notifier_call = arche_platform_pm_notifier;
526         ret = register_pm_notifier(&arche_pdata->pm_notifier);
527
528         if (ret) {
529                 dev_err(dev, "failed to register pm notifier %d\n", ret);
530                 goto err_device_remove;
531         }
532
533         /* Explicitly power off if requested */
534         if (!of_property_read_bool(pdev->dev.of_node, "arche,init-off")) {
535                 mutex_lock(&arche_pdata->platform_state_mutex);
536                 ret = arche_platform_coldboot_seq(arche_pdata);
537                 if (ret) {
538                         dev_err(dev, "Failed to cold boot svc %d\n", ret);
539                         goto err_coldboot;
540                 }
541                 arche_platform_wd_irq_en(arche_pdata);
542                 mutex_unlock(&arche_pdata->platform_state_mutex);
543         }
544
545         dev_info(dev, "Device registered successfully\n");
546         return 0;
547
548 err_coldboot:
549         mutex_unlock(&arche_pdata->platform_state_mutex);
550 err_device_remove:
551         device_remove_file(&pdev->dev, &dev_attr_state);
552         return ret;
553 }
554
555 static int arche_remove_child(struct device *dev, void *unused)
556 {
557         struct platform_device *pdev = to_platform_device(dev);
558
559         platform_device_unregister(pdev);
560
561         return 0;
562 }
563
564 static int arche_platform_remove(struct platform_device *pdev)
565 {
566         struct arche_platform_drvdata *arche_pdata = platform_get_drvdata(pdev);
567
568         unregister_pm_notifier(&arche_pdata->pm_notifier);
569         device_remove_file(&pdev->dev, &dev_attr_state);
570         device_for_each_child(&pdev->dev, NULL, arche_remove_child);
571         arche_platform_poweroff_seq(arche_pdata);
572
573         if (usb3613_hub_mode_ctrl(false))
574                 dev_warn(arche_pdata->dev, "failed to control hub device\n");
575                 /* TODO: Should we do anything more here ?? */
576         return 0;
577 }
578
579 static __maybe_unused int arche_platform_suspend(struct device *dev)
580 {
581         /*
582          * If timing profile premits, we may shutdown bridge
583          * completely
584          *
585          * TODO: sequence ??
586          *
587          * Also, need to make sure we meet precondition for unipro suspend
588          * Precondition: Definition ???
589          */
590         return 0;
591 }
592
593 static __maybe_unused int arche_platform_resume(struct device *dev)
594 {
595         /*
596          * Atleast for ES2 we have to meet the delay requirement between
597          * unipro switch and AP bridge init, depending on whether bridge is in
598          * OFF state or standby state.
599          *
600          * Based on whether bridge is in standby or OFF state we may have to
601          * assert multiple signals. Please refer to WDM spec, for more info.
602          *
603          */
604         return 0;
605 }
606
607 static void arche_platform_shutdown(struct platform_device *pdev)
608 {
609         struct arche_platform_drvdata *arche_pdata = platform_get_drvdata(pdev);
610
611         arche_platform_poweroff_seq(arche_pdata);
612
613         usb3613_hub_mode_ctrl(false);
614 }
615
616 static SIMPLE_DEV_PM_OPS(arche_platform_pm_ops,
617                         arche_platform_suspend,
618                         arche_platform_resume);
619
620 static const struct of_device_id arche_platform_of_match[] = {
621         /* Use PID/VID of SVC device */
622         { .compatible = "google,arche-platform", },
623         { },
624 };
625
626 static const struct of_device_id arche_combined_id[] = {
627         /* Use PID/VID of SVC device */
628         { .compatible = "google,arche-platform", },
629         { .compatible = "usbffff,2", },
630         { },
631 };
632 MODULE_DEVICE_TABLE(of, arche_combined_id);
633
634 static struct platform_driver arche_platform_device_driver = {
635         .probe          = arche_platform_probe,
636         .remove         = arche_platform_remove,
637         .shutdown       = arche_platform_shutdown,
638         .driver         = {
639                 .name   = "arche-platform-ctrl",
640                 .pm     = &arche_platform_pm_ops,
641                 .of_match_table = arche_platform_of_match,
642         }
643 };
644
645 static int __init arche_init(void)
646 {
647         int retval;
648
649         retval = platform_driver_register(&arche_platform_device_driver);
650         if (retval)
651                 return retval;
652
653         retval = arche_apb_init();
654         if (retval)
655                 platform_driver_unregister(&arche_platform_device_driver);
656
657         return retval;
658 }
659 module_init(arche_init);
660
661 static void __exit arche_exit(void)
662 {
663         arche_apb_exit();
664         platform_driver_unregister(&arche_platform_device_driver);
665 }
666 module_exit(arche_exit);
667
668 MODULE_LICENSE("GPL v2");
669 MODULE_AUTHOR("Vaibhav Hiremath <vaibhav.hiremath@linaro.org>");
670 MODULE_DESCRIPTION("Arche Platform Driver");