Eric Lee / smarc-fsl-linux-kernel

Blame view

drivers/gpio/gpio-viperboard.c 12.1 KB
edit raw normal view history
9d5b72de0   Lars Poeschel   gpio: Add viperbo... 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
 
  /*
   *  Nano River Technologies viperboard GPIO lib driver
   *
   *  (C) 2012 by Lemonage GmbH
   *  Author: Lars Poeschel <poeschel@lemonage.de>
   *  All rights reserved.
   *
   *  This program is free software; you can redistribute  it and/or modify it
   *  under  the terms of  the GNU General  Public License as published by the
   *  Free Software Foundation;  either version 2 of the	License, or (at your
   *  option) any later version.
   *
   */
  
  #include <linux/kernel.h>
  #include <linux/errno.h>
  #include <linux/module.h>
  #include <linux/slab.h>
  #include <linux/types.h>
  #include <linux/mutex.h>
  #include <linux/platform_device.h>
  
  #include <linux/usb.h>
  #include <linux/gpio.h>
  
  #include <linux/mfd/viperboard.h>
  
  #define VPRBRD_GPIOA_CLK_1MHZ		0
  #define VPRBRD_GPIOA_CLK_100KHZ		1
  #define VPRBRD_GPIOA_CLK_10KHZ		2
  #define VPRBRD_GPIOA_CLK_1KHZ		3
  #define VPRBRD_GPIOA_CLK_100HZ		4
  #define VPRBRD_GPIOA_CLK_10HZ		5
  
  #define VPRBRD_GPIOA_FREQ_DEFAULT	1000
  
  #define VPRBRD_GPIOA_CMD_CONT		0x00
  #define VPRBRD_GPIOA_CMD_PULSE		0x01
  #define VPRBRD_GPIOA_CMD_PWM		0x02
  #define VPRBRD_GPIOA_CMD_SETOUT		0x03
  #define VPRBRD_GPIOA_CMD_SETIN		0x04
  #define VPRBRD_GPIOA_CMD_SETINT		0x05
  #define VPRBRD_GPIOA_CMD_GETIN		0x06
  
  #define VPRBRD_GPIOB_CMD_SETDIR		0x00
  #define VPRBRD_GPIOB_CMD_SETVAL		0x01
  
  struct vprbrd_gpioa_msg {
  	u8 cmd;
  	u8 clk;
  	u8 offset;
  	u8 t1;
  	u8 t2;
  	u8 invert;
  	u8 pwmlevel;
  	u8 outval;
  	u8 risefall;
  	u8 answer;
  	u8 __fill;
  } __packed;
  
  struct vprbrd_gpiob_msg {
  	u8 cmd;
  	u16 val;
  	u16 mask;
  } __packed;
  
  struct vprbrd_gpio {
  	struct gpio_chip gpioa; /* gpio a related things */
  	u32 gpioa_out;
  	u32 gpioa_val;
  	struct gpio_chip gpiob; /* gpio b related things */
  	u32 gpiob_out;
  	u32 gpiob_val;
  	struct vprbrd *vb;
  };
  
  /* gpioa sampling clock module parameter */
  static unsigned char gpioa_clk;
  static unsigned int gpioa_freq = VPRBRD_GPIOA_FREQ_DEFAULT;
  module_param(gpioa_freq, uint, 0);
  MODULE_PARM_DESC(gpioa_freq,
  	"gpio-a sampling freq in Hz (default is 1000Hz) valid values: 10, 100, 1000, 10000, 100000, 1000000");
  
  /* ----- begin of gipo a chip -------------------------------------------- */
  
  static int vprbrd_gpioa_get(struct gpio_chip *chip,
  		unsigned offset)
  {
  	int ret, answer, error = 0;
2a873c8d6   Linus Walleij   gpio: viperboard:... 
91
 
  	struct vprbrd_gpio *gpio = gpiochip_get_data(chip);
9d5b72de0   Lars Poeschel   gpio: Add viperbo... 
92
93
94
95
96
 
  	struct vprbrd *vb = gpio->vb;
  	struct vprbrd_gpioa_msg *gamsg = (struct vprbrd_gpioa_msg *)vb->buf;
  
  	/* if io is set to output, just return the saved value */
  	if (gpio->gpioa_out & (1 << offset))
80776df4f   Linus Walleij   gpio: viperboard:... 
97
 
  		return !!(gpio->gpioa_val & (1 << offset));
9d5b72de0   Lars Poeschel   gpio: Add viperbo... 
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
 
  
  	mutex_lock(&vb->lock);
  
  	gamsg->cmd = VPRBRD_GPIOA_CMD_GETIN;
  	gamsg->clk = 0x00;
  	gamsg->offset = offset;
  	gamsg->t1 = 0x00;
  	gamsg->t2 = 0x00;
  	gamsg->invert = 0x00;
  	gamsg->pwmlevel = 0x00;
  	gamsg->outval = 0x00;
  	gamsg->risefall = 0x00;
  	gamsg->answer = 0x00;
  	gamsg->__fill = 0x00;
  
  	ret = usb_control_msg(vb->usb_dev, usb_sndctrlpipe(vb->usb_dev, 0),
  		VPRBRD_USB_REQUEST_GPIOA, VPRBRD_USB_TYPE_OUT, 0x0000,
  		0x0000, gamsg, sizeof(struct vprbrd_gpioa_msg),
  		VPRBRD_USB_TIMEOUT_MS);
  	if (ret != sizeof(struct vprbrd_gpioa_msg))
  		error = -EREMOTEIO;
  
  	ret = usb_control_msg(vb->usb_dev, usb_rcvctrlpipe(vb->usb_dev, 0),
  		VPRBRD_USB_REQUEST_GPIOA, VPRBRD_USB_TYPE_IN, 0x0000,
  		0x0000, gamsg, sizeof(struct vprbrd_gpioa_msg),
  		VPRBRD_USB_TIMEOUT_MS);
  	answer = gamsg->answer & 0x01;
  
  	mutex_unlock(&vb->lock);
  
  	if (ret != sizeof(struct vprbrd_gpioa_msg))
  		error = -EREMOTEIO;
  
  	if (error)
  		return error;
  
  	return answer;
  }
  
  static void vprbrd_gpioa_set(struct gpio_chip *chip,
  		unsigned offset, int value)
  {
  	int ret;
2a873c8d6   Linus Walleij   gpio: viperboard:... 
141
 
  	struct vprbrd_gpio *gpio = gpiochip_get_data(chip);
9d5b72de0   Lars Poeschel   gpio: Add viperbo... 
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
 
  	struct vprbrd *vb = gpio->vb;
  	struct vprbrd_gpioa_msg *gamsg = (struct vprbrd_gpioa_msg *)vb->buf;
  
  	if (gpio->gpioa_out & (1 << offset)) {
  		if (value)
  			gpio->gpioa_val |= (1 << offset);
  		else
  			gpio->gpioa_val &= ~(1 << offset);
  
  		mutex_lock(&vb->lock);
  
  		gamsg->cmd = VPRBRD_GPIOA_CMD_SETOUT;
  		gamsg->clk = 0x00;
  		gamsg->offset = offset;
  		gamsg->t1 = 0x00;
  		gamsg->t2 = 0x00;
  		gamsg->invert = 0x00;
  		gamsg->pwmlevel = 0x00;
  		gamsg->outval = value;
  		gamsg->risefall = 0x00;
  		gamsg->answer = 0x00;
  		gamsg->__fill = 0x00;
  
  		ret = usb_control_msg(vb->usb_dev,
  			usb_sndctrlpipe(vb->usb_dev, 0),
  			VPRBRD_USB_REQUEST_GPIOA, VPRBRD_USB_TYPE_OUT,
  			0x0000,	0x0000, gamsg,
  			sizeof(struct vprbrd_gpioa_msg), VPRBRD_USB_TIMEOUT_MS);
  
  		mutex_unlock(&vb->lock);
  
  		if (ret != sizeof(struct vprbrd_gpioa_msg))
58383c784   Linus Walleij   gpio: change memb... 
174
175
 
  			dev_err(chip->parent, "usb error setting pin value
  ");
9d5b72de0   Lars Poeschel   gpio: Add viperbo... 
176
177
178
179
180
181
182
 
  	}
  }
  
  static int vprbrd_gpioa_direction_input(struct gpio_chip *chip,
  			unsigned offset)
  {
  	int ret;
2a873c8d6   Linus Walleij   gpio: viperboard:... 
183
 
  	struct vprbrd_gpio *gpio = gpiochip_get_data(chip);
9d5b72de0   Lars Poeschel   gpio: Add viperbo... 
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
 
  	struct vprbrd *vb = gpio->vb;
  	struct vprbrd_gpioa_msg *gamsg = (struct vprbrd_gpioa_msg *)vb->buf;
  
  	gpio->gpioa_out &= ~(1 << offset);
  
  	mutex_lock(&vb->lock);
  
  	gamsg->cmd = VPRBRD_GPIOA_CMD_SETIN;
  	gamsg->clk = gpioa_clk;
  	gamsg->offset = offset;
  	gamsg->t1 = 0x00;
  	gamsg->t2 = 0x00;
  	gamsg->invert = 0x00;
  	gamsg->pwmlevel = 0x00;
  	gamsg->outval = 0x00;
  	gamsg->risefall = 0x00;
  	gamsg->answer = 0x00;
  	gamsg->__fill = 0x00;
  
  	ret = usb_control_msg(vb->usb_dev, usb_sndctrlpipe(vb->usb_dev, 0),
  		VPRBRD_USB_REQUEST_GPIOA, VPRBRD_USB_TYPE_OUT, 0x0000,
  		0x0000, gamsg, sizeof(struct vprbrd_gpioa_msg),
  		VPRBRD_USB_TIMEOUT_MS);
  
  	mutex_unlock(&vb->lock);
  
  	if (ret != sizeof(struct vprbrd_gpioa_msg))
  		return -EREMOTEIO;
  
  	return 0;
  }
  
  static int vprbrd_gpioa_direction_output(struct gpio_chip *chip,
  			unsigned offset, int value)
  {
  	int ret;
2a873c8d6   Linus Walleij   gpio: viperboard:... 
220
 
  	struct vprbrd_gpio *gpio = gpiochip_get_data(chip);
9d5b72de0   Lars Poeschel   gpio: Add viperbo... 
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
 
  	struct vprbrd *vb = gpio->vb;
  	struct vprbrd_gpioa_msg *gamsg = (struct vprbrd_gpioa_msg *)vb->buf;
  
  	gpio->gpioa_out |= (1 << offset);
  	if (value)
  		gpio->gpioa_val |= (1 << offset);
  	else
  		gpio->gpioa_val &= ~(1 << offset);
  
  	mutex_lock(&vb->lock);
  
  	gamsg->cmd = VPRBRD_GPIOA_CMD_SETOUT;
  	gamsg->clk = 0x00;
  	gamsg->offset = offset;
  	gamsg->t1 = 0x00;
  	gamsg->t2 = 0x00;
  	gamsg->invert = 0x00;
  	gamsg->pwmlevel = 0x00;
  	gamsg->outval = value;
  	gamsg->risefall = 0x00;
  	gamsg->answer = 0x00;
  	gamsg->__fill = 0x00;
  
  	ret = usb_control_msg(vb->usb_dev, usb_sndctrlpipe(vb->usb_dev, 0),
  		VPRBRD_USB_REQUEST_GPIOA, VPRBRD_USB_TYPE_OUT, 0x0000,
  		0x0000, gamsg, sizeof(struct vprbrd_gpioa_msg),
  		VPRBRD_USB_TIMEOUT_MS);
  
  	mutex_unlock(&vb->lock);
  
  	if (ret != sizeof(struct vprbrd_gpioa_msg))
  		return -EREMOTEIO;
  
  	return 0;
  }
  
  /* ----- end of gpio a chip ---------------------------------------------- */
  
  /* ----- begin of gipo b chip -------------------------------------------- */
  
  static int vprbrd_gpiob_setdir(struct vprbrd *vb, unsigned offset,
  	unsigned dir)
  {
  	struct vprbrd_gpiob_msg *gbmsg = (struct vprbrd_gpiob_msg *)vb->buf;
  	int ret;
  
  	gbmsg->cmd = VPRBRD_GPIOB_CMD_SETDIR;
  	gbmsg->val = cpu_to_be16(dir << offset);
  	gbmsg->mask = cpu_to_be16(0x0001 << offset);
  
  	ret = usb_control_msg(vb->usb_dev, usb_sndctrlpipe(vb->usb_dev, 0),
  		VPRBRD_USB_REQUEST_GPIOB, VPRBRD_USB_TYPE_OUT, 0x0000,
  		0x0000, gbmsg, sizeof(struct vprbrd_gpiob_msg),
  		VPRBRD_USB_TIMEOUT_MS);
  
  	if (ret != sizeof(struct vprbrd_gpiob_msg))
  		return -EREMOTEIO;
  
  	return 0;
  }
  
  static int vprbrd_gpiob_get(struct gpio_chip *chip,
  		unsigned offset)
  {
  	int ret;
  	u16 val;
2a873c8d6   Linus Walleij   gpio: viperboard:... 
287
 
  	struct vprbrd_gpio *gpio = gpiochip_get_data(chip);
9d5b72de0   Lars Poeschel   gpio: Add viperbo... 
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
 
  	struct vprbrd *vb = gpio->vb;
  	struct vprbrd_gpiob_msg *gbmsg = (struct vprbrd_gpiob_msg *)vb->buf;
  
  	/* if io is set to output, just return the saved value */
  	if (gpio->gpiob_out & (1 << offset))
  		return gpio->gpiob_val & (1 << offset);
  
  	mutex_lock(&vb->lock);
  
  	ret = usb_control_msg(vb->usb_dev, usb_rcvctrlpipe(vb->usb_dev, 0),
  		VPRBRD_USB_REQUEST_GPIOB, VPRBRD_USB_TYPE_IN, 0x0000,
  		0x0000, gbmsg,	sizeof(struct vprbrd_gpiob_msg),
  		VPRBRD_USB_TIMEOUT_MS);
  	val = gbmsg->val;
  
  	mutex_unlock(&vb->lock);
  
  	if (ret != sizeof(struct vprbrd_gpiob_msg))
  		return ret;
  
  	/* cache the read values */
  	gpio->gpiob_val = be16_to_cpu(val);
  
  	return (gpio->gpiob_val >> offset) & 0x1;
  }
  
  static void vprbrd_gpiob_set(struct gpio_chip *chip,
  		unsigned offset, int value)
  {
  	int ret;
2a873c8d6   Linus Walleij   gpio: viperboard:... 
318
 
  	struct vprbrd_gpio *gpio = gpiochip_get_data(chip);
9d5b72de0   Lars Poeschel   gpio: Add viperbo... 
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
 
  	struct vprbrd *vb = gpio->vb;
  	struct vprbrd_gpiob_msg *gbmsg = (struct vprbrd_gpiob_msg *)vb->buf;
  
  	if (gpio->gpiob_out & (1 << offset)) {
  		if (value)
  			gpio->gpiob_val |= (1 << offset);
  		else
  			gpio->gpiob_val &= ~(1 << offset);
  
  		mutex_lock(&vb->lock);
  
  		gbmsg->cmd = VPRBRD_GPIOB_CMD_SETVAL;
  		gbmsg->val = cpu_to_be16(value << offset);
  		gbmsg->mask = cpu_to_be16(0x0001 << offset);
  
  		ret = usb_control_msg(vb->usb_dev,
  			usb_sndctrlpipe(vb->usb_dev, 0),
  			VPRBRD_USB_REQUEST_GPIOB, VPRBRD_USB_TYPE_OUT,
  			0x0000,	0x0000, gbmsg,
  			sizeof(struct vprbrd_gpiob_msg), VPRBRD_USB_TIMEOUT_MS);
  
  		mutex_unlock(&vb->lock);
  
  		if (ret != sizeof(struct vprbrd_gpiob_msg))
58383c784   Linus Walleij   gpio: change memb... 
343
344
 
  			dev_err(chip->parent, "usb error setting pin value
  ");
9d5b72de0   Lars Poeschel   gpio: Add viperbo... 
345
346
347
348
349
350
351
 
  	}
  }
  
  static int vprbrd_gpiob_direction_input(struct gpio_chip *chip,
  			unsigned offset)
  {
  	int ret;
2a873c8d6   Linus Walleij   gpio: viperboard:... 
352
 
  	struct vprbrd_gpio *gpio = gpiochip_get_data(chip);
9d5b72de0   Lars Poeschel   gpio: Add viperbo... 
353
354
355
356
357
358
359
360
361
362
363
 
  	struct vprbrd *vb = gpio->vb;
  
  	gpio->gpiob_out &= ~(1 << offset);
  
  	mutex_lock(&vb->lock);
  
  	ret = vprbrd_gpiob_setdir(vb, offset, 0);
  
  	mutex_unlock(&vb->lock);
  
  	if (ret)
58383c784   Linus Walleij   gpio: change memb... 
364
365
 
  		dev_err(chip->parent, "usb error setting pin to input
  ");
9d5b72de0   Lars Poeschel   gpio: Add viperbo... 
366
367
368
369
370
371
372
373
 
  
  	return ret;
  }
  
  static int vprbrd_gpiob_direction_output(struct gpio_chip *chip,
  			unsigned offset, int value)
  {
  	int ret;
2a873c8d6   Linus Walleij   gpio: viperboard:... 
374
 
  	struct vprbrd_gpio *gpio = gpiochip_get_data(chip);
9d5b72de0   Lars Poeschel   gpio: Add viperbo... 
375
376
377
 
  	struct vprbrd *vb = gpio->vb;
  
  	gpio->gpiob_out |= (1 << offset);
9d5b72de0   Lars Poeschel   gpio: Add viperbo... 
378
379
380
381
382
 
  
  	mutex_lock(&vb->lock);
  
  	ret = vprbrd_gpiob_setdir(vb, offset, 1);
  	if (ret)
58383c784   Linus Walleij   gpio: change memb... 
383
384
 
  		dev_err(chip->parent, "usb error setting pin to output
  ");
9d5b72de0   Lars Poeschel   gpio: Add viperbo... 
385
386
387
388
389
390
391
392
393
 
  
  	mutex_unlock(&vb->lock);
  
  	vprbrd_gpiob_set(chip, offset, value);
  
  	return ret;
  }
  
  /* ----- end of gpio b chip ---------------------------------------------- */
0fe763c57   Greg Kroah-Hartman   Drivers: misc: re... 
394
 
  static int vprbrd_gpio_probe(struct platform_device *pdev)
9d5b72de0   Lars Poeschel   gpio: Add viperbo... 
395
396
397
398
399
400
401
402
403
404
405
406
 
  {
  	struct vprbrd *vb = dev_get_drvdata(pdev->dev.parent);
  	struct vprbrd_gpio *vb_gpio;
  	int ret;
  
  	vb_gpio = devm_kzalloc(&pdev->dev, sizeof(*vb_gpio), GFP_KERNEL);
  	if (vb_gpio == NULL)
  		return -ENOMEM;
  
  	vb_gpio->vb = vb;
  	/* registering gpio a */
  	vb_gpio->gpioa.label = "viperboard gpio a";
58383c784   Linus Walleij   gpio: change memb... 
407
 
  	vb_gpio->gpioa.parent = &pdev->dev;
9d5b72de0   Lars Poeschel   gpio: Add viperbo... 
408
409
410
 
  	vb_gpio->gpioa.owner = THIS_MODULE;
  	vb_gpio->gpioa.base = -1;
  	vb_gpio->gpioa.ngpio = 16;
9fb1f39eb   Linus Walleij   gpio/pinctrl: mak... 
411
 
  	vb_gpio->gpioa.can_sleep = true;
9d5b72de0   Lars Poeschel   gpio: Add viperbo... 
412
413
414
415
 
  	vb_gpio->gpioa.set = vprbrd_gpioa_set;
  	vb_gpio->gpioa.get = vprbrd_gpioa_get;
  	vb_gpio->gpioa.direction_input = vprbrd_gpioa_direction_input;
  	vb_gpio->gpioa.direction_output = vprbrd_gpioa_direction_output;
45338c3aa   Laxman Dewangan   gpio: viperboard:... 
416
 
  	ret = devm_gpiochip_add_data(&pdev->dev, &vb_gpio->gpioa, vb_gpio);
9d5b72de0   Lars Poeschel   gpio: Add viperbo... 
417
 
  	if (ret < 0) {
58383c784   Linus Walleij   gpio: change memb... 
418
 
  		dev_err(vb_gpio->gpioa.parent, "could not add gpio a");
45338c3aa   Laxman Dewangan   gpio: viperboard:... 
419
 
  		return ret;
9d5b72de0   Lars Poeschel   gpio: Add viperbo... 
420
421
422
423
 
  	}
  
  	/* registering gpio b */
  	vb_gpio->gpiob.label = "viperboard gpio b";
58383c784   Linus Walleij   gpio: change memb... 
424
 
  	vb_gpio->gpiob.parent = &pdev->dev;
9d5b72de0   Lars Poeschel   gpio: Add viperbo... 
425
426
427
 
  	vb_gpio->gpiob.owner = THIS_MODULE;
  	vb_gpio->gpiob.base = -1;
  	vb_gpio->gpiob.ngpio = 16;
9fb1f39eb   Linus Walleij   gpio/pinctrl: mak... 
428
 
  	vb_gpio->gpiob.can_sleep = true;
9d5b72de0   Lars Poeschel   gpio: Add viperbo... 
429
430
431
432
 
  	vb_gpio->gpiob.set = vprbrd_gpiob_set;
  	vb_gpio->gpiob.get = vprbrd_gpiob_get;
  	vb_gpio->gpiob.direction_input = vprbrd_gpiob_direction_input;
  	vb_gpio->gpiob.direction_output = vprbrd_gpiob_direction_output;
45338c3aa   Laxman Dewangan   gpio: viperboard:... 
433
 
  	ret = devm_gpiochip_add_data(&pdev->dev, &vb_gpio->gpiob, vb_gpio);
9d5b72de0   Lars Poeschel   gpio: Add viperbo... 
434
 
  	if (ret < 0) {
58383c784   Linus Walleij   gpio: change memb... 
435
 
  		dev_err(vb_gpio->gpiob.parent, "could not add gpio b");
45338c3aa   Laxman Dewangan   gpio: viperboard:... 
436
 
  		return ret;
9d5b72de0   Lars Poeschel   gpio: Add viperbo... 
437
438
439
440
441
 
  	}
  
  	platform_set_drvdata(pdev, vb_gpio);
  
  	return ret;
9d5b72de0   Lars Poeschel   gpio: Add viperbo... 
442
443
444
445
 
  }
  
  static struct platform_driver vprbrd_gpio_driver = {
  	.driver.name	= "viperboard-gpio",
9d5b72de0   Lars Poeschel   gpio: Add viperbo... 
446
 
  	.probe		= vprbrd_gpio_probe,
9d5b72de0   Lars Poeschel   gpio: Add viperbo... 
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
 
  };
  
  static int __init vprbrd_gpio_init(void)
  {
  	switch (gpioa_freq) {
  	case 1000000:
  		gpioa_clk = VPRBRD_GPIOA_CLK_1MHZ;
  		break;
  	case 100000:
  		gpioa_clk = VPRBRD_GPIOA_CLK_100KHZ;
  		break;
  	case 10000:
  		gpioa_clk = VPRBRD_GPIOA_CLK_10KHZ;
  		break;
  	case 1000:
  		gpioa_clk = VPRBRD_GPIOA_CLK_1KHZ;
  		break;
  	case 100:
  		gpioa_clk = VPRBRD_GPIOA_CLK_100HZ;
  		break;
  	case 10:
  		gpioa_clk = VPRBRD_GPIOA_CLK_10HZ;
  		break;
  	default:
  		pr_warn("invalid gpioa_freq (%d)
  ", gpioa_freq);
  		gpioa_clk = VPRBRD_GPIOA_CLK_1KHZ;
  	}
  
  	return platform_driver_register(&vprbrd_gpio_driver);
  }
  subsys_initcall(vprbrd_gpio_init);
  
  static void __exit vprbrd_gpio_exit(void)
  {
  	platform_driver_unregister(&vprbrd_gpio_driver);
  }
  module_exit(vprbrd_gpio_exit);
  
  MODULE_AUTHOR("Lars Poeschel <poeschel@lemonage.de>");
  MODULE_DESCRIPTION("GPIO driver for Nano River Techs Viperboard");
  MODULE_LICENSE("GPL");
  MODULE_ALIAS("platform:viperboard-gpio");