1/*
2 *  Nano River Technologies viperboard GPIO lib driver
3 *
4 *  (C) 2012 by Lemonage GmbH
5 *  Author: Lars Poeschel <poeschel@lemonage.de>
6 *  All rights reserved.
7 *
8 *  This program is free software; you can redistribute  it and/or modify it
9 *  under  the terms of  the GNU General  Public License as published by the
10 *  Free Software Foundation;  either version 2 of the	License, or (at your
11 *  option) any later version.
12 *
13 */
14
15#include <linux/kernel.h>
16#include <linux/errno.h>
17#include <linux/module.h>
18#include <linux/slab.h>
19#include <linux/types.h>
20#include <linux/mutex.h>
21#include <linux/platform_device.h>
22
23#include <linux/usb.h>
24#include <linux/gpio.h>
25
26#include <linux/mfd/viperboard.h>
27
28#define VPRBRD_GPIOA_CLK_1MHZ		0
29#define VPRBRD_GPIOA_CLK_100KHZ		1
30#define VPRBRD_GPIOA_CLK_10KHZ		2
31#define VPRBRD_GPIOA_CLK_1KHZ		3
32#define VPRBRD_GPIOA_CLK_100HZ		4
33#define VPRBRD_GPIOA_CLK_10HZ		5
34
35#define VPRBRD_GPIOA_FREQ_DEFAULT	1000
36
37#define VPRBRD_GPIOA_CMD_CONT		0x00
38#define VPRBRD_GPIOA_CMD_PULSE		0x01
39#define VPRBRD_GPIOA_CMD_PWM		0x02
40#define VPRBRD_GPIOA_CMD_SETOUT		0x03
41#define VPRBRD_GPIOA_CMD_SETIN		0x04
42#define VPRBRD_GPIOA_CMD_SETINT		0x05
43#define VPRBRD_GPIOA_CMD_GETIN		0x06
44
45#define VPRBRD_GPIOB_CMD_SETDIR		0x00
46#define VPRBRD_GPIOB_CMD_SETVAL		0x01
47
48struct vprbrd_gpioa_msg {
49	u8 cmd;
50	u8 clk;
51	u8 offset;
52	u8 t1;
53	u8 t2;
54	u8 invert;
55	u8 pwmlevel;
56	u8 outval;
57	u8 risefall;
58	u8 answer;
59	u8 __fill;
60} __packed;
61
62struct vprbrd_gpiob_msg {
63	u8 cmd;
64	u16 val;
65	u16 mask;
66} __packed;
67
68struct vprbrd_gpio {
69	struct gpio_chip gpioa; /* gpio a related things */
70	u32 gpioa_out;
71	u32 gpioa_val;
72	struct gpio_chip gpiob; /* gpio b related things */
73	u32 gpiob_out;
74	u32 gpiob_val;
75	struct vprbrd *vb;
76};
77
78/* gpioa sampling clock module parameter */
79static unsigned char gpioa_clk;
80static unsigned int gpioa_freq = VPRBRD_GPIOA_FREQ_DEFAULT;
81module_param(gpioa_freq, uint, 0);
82MODULE_PARM_DESC(gpioa_freq,
83	"gpio-a sampling freq in Hz (default is 1000Hz) valid values: 10, 100, 1000, 10000, 100000, 1000000");
84
85/* ----- begin of gipo a chip -------------------------------------------- */
86
87static int vprbrd_gpioa_get(struct gpio_chip *chip,
88		unsigned offset)
89{
90	int ret, answer, error = 0;
91	struct vprbrd_gpio *gpio =
92			container_of(chip, struct vprbrd_gpio, gpioa);
93	struct vprbrd *vb = gpio->vb;
94	struct vprbrd_gpioa_msg *gamsg = (struct vprbrd_gpioa_msg *)vb->buf;
95
96	/* if io is set to output, just return the saved value */
97	if (gpio->gpioa_out & (1 << offset))
98		return gpio->gpioa_val & (1 << offset);
99
100	mutex_lock(&vb->lock);
101
102	gamsg->cmd = VPRBRD_GPIOA_CMD_GETIN;
103	gamsg->clk = 0x00;
104	gamsg->offset = offset;
105	gamsg->t1 = 0x00;
106	gamsg->t2 = 0x00;
107	gamsg->invert = 0x00;
108	gamsg->pwmlevel = 0x00;
109	gamsg->outval = 0x00;
110	gamsg->risefall = 0x00;
111	gamsg->answer = 0x00;
112	gamsg->__fill = 0x00;
113
114	ret = usb_control_msg(vb->usb_dev, usb_sndctrlpipe(vb->usb_dev, 0),
115		VPRBRD_USB_REQUEST_GPIOA, VPRBRD_USB_TYPE_OUT, 0x0000,
116		0x0000, gamsg, sizeof(struct vprbrd_gpioa_msg),
117		VPRBRD_USB_TIMEOUT_MS);
118	if (ret != sizeof(struct vprbrd_gpioa_msg))
119		error = -EREMOTEIO;
120
121	ret = usb_control_msg(vb->usb_dev, usb_rcvctrlpipe(vb->usb_dev, 0),
122		VPRBRD_USB_REQUEST_GPIOA, VPRBRD_USB_TYPE_IN, 0x0000,
123		0x0000, gamsg, sizeof(struct vprbrd_gpioa_msg),
124		VPRBRD_USB_TIMEOUT_MS);
125	answer = gamsg->answer & 0x01;
126
127	mutex_unlock(&vb->lock);
128
129	if (ret != sizeof(struct vprbrd_gpioa_msg))
130		error = -EREMOTEIO;
131
132	if (error)
133		return error;
134
135	return answer;
136}
137
138static void vprbrd_gpioa_set(struct gpio_chip *chip,
139		unsigned offset, int value)
140{
141	int ret;
142	struct vprbrd_gpio *gpio =
143			container_of(chip, struct vprbrd_gpio, gpioa);
144	struct vprbrd *vb = gpio->vb;
145	struct vprbrd_gpioa_msg *gamsg = (struct vprbrd_gpioa_msg *)vb->buf;
146
147	if (gpio->gpioa_out & (1 << offset)) {
148		if (value)
149			gpio->gpioa_val |= (1 << offset);
150		else
151			gpio->gpioa_val &= ~(1 << offset);
152
153		mutex_lock(&vb->lock);
154
155		gamsg->cmd = VPRBRD_GPIOA_CMD_SETOUT;
156		gamsg->clk = 0x00;
157		gamsg->offset = offset;
158		gamsg->t1 = 0x00;
159		gamsg->t2 = 0x00;
160		gamsg->invert = 0x00;
161		gamsg->pwmlevel = 0x00;
162		gamsg->outval = value;
163		gamsg->risefall = 0x00;
164		gamsg->answer = 0x00;
165		gamsg->__fill = 0x00;
166
167		ret = usb_control_msg(vb->usb_dev,
168			usb_sndctrlpipe(vb->usb_dev, 0),
169			VPRBRD_USB_REQUEST_GPIOA, VPRBRD_USB_TYPE_OUT,
170			0x0000,	0x0000, gamsg,
171			sizeof(struct vprbrd_gpioa_msg), VPRBRD_USB_TIMEOUT_MS);
172
173		mutex_unlock(&vb->lock);
174
175		if (ret != sizeof(struct vprbrd_gpioa_msg))
176			dev_err(chip->dev, "usb error setting pin value\n");
177	}
178}
179
180static int vprbrd_gpioa_direction_input(struct gpio_chip *chip,
181			unsigned offset)
182{
183	int ret;
184	struct vprbrd_gpio *gpio =
185			container_of(chip, struct vprbrd_gpio, gpioa);
186	struct vprbrd *vb = gpio->vb;
187	struct vprbrd_gpioa_msg *gamsg = (struct vprbrd_gpioa_msg *)vb->buf;
188
189	gpio->gpioa_out &= ~(1 << offset);
190
191	mutex_lock(&vb->lock);
192
193	gamsg->cmd = VPRBRD_GPIOA_CMD_SETIN;
194	gamsg->clk = gpioa_clk;
195	gamsg->offset = offset;
196	gamsg->t1 = 0x00;
197	gamsg->t2 = 0x00;
198	gamsg->invert = 0x00;
199	gamsg->pwmlevel = 0x00;
200	gamsg->outval = 0x00;
201	gamsg->risefall = 0x00;
202	gamsg->answer = 0x00;
203	gamsg->__fill = 0x00;
204
205	ret = usb_control_msg(vb->usb_dev, usb_sndctrlpipe(vb->usb_dev, 0),
206		VPRBRD_USB_REQUEST_GPIOA, VPRBRD_USB_TYPE_OUT, 0x0000,
207		0x0000, gamsg, sizeof(struct vprbrd_gpioa_msg),
208		VPRBRD_USB_TIMEOUT_MS);
209
210	mutex_unlock(&vb->lock);
211
212	if (ret != sizeof(struct vprbrd_gpioa_msg))
213		return -EREMOTEIO;
214
215	return 0;
216}
217
218static int vprbrd_gpioa_direction_output(struct gpio_chip *chip,
219			unsigned offset, int value)
220{
221	int ret;
222	struct vprbrd_gpio *gpio =
223			container_of(chip, struct vprbrd_gpio, gpioa);
224	struct vprbrd *vb = gpio->vb;
225	struct vprbrd_gpioa_msg *gamsg = (struct vprbrd_gpioa_msg *)vb->buf;
226
227	gpio->gpioa_out |= (1 << offset);
228	if (value)
229		gpio->gpioa_val |= (1 << offset);
230	else
231		gpio->gpioa_val &= ~(1 << offset);
232
233	mutex_lock(&vb->lock);
234
235	gamsg->cmd = VPRBRD_GPIOA_CMD_SETOUT;
236	gamsg->clk = 0x00;
237	gamsg->offset = offset;
238	gamsg->t1 = 0x00;
239	gamsg->t2 = 0x00;
240	gamsg->invert = 0x00;
241	gamsg->pwmlevel = 0x00;
242	gamsg->outval = value;
243	gamsg->risefall = 0x00;
244	gamsg->answer = 0x00;
245	gamsg->__fill = 0x00;
246
247	ret = usb_control_msg(vb->usb_dev, usb_sndctrlpipe(vb->usb_dev, 0),
248		VPRBRD_USB_REQUEST_GPIOA, VPRBRD_USB_TYPE_OUT, 0x0000,
249		0x0000, gamsg, sizeof(struct vprbrd_gpioa_msg),
250		VPRBRD_USB_TIMEOUT_MS);
251
252	mutex_unlock(&vb->lock);
253
254	if (ret != sizeof(struct vprbrd_gpioa_msg))
255		return -EREMOTEIO;
256
257	return 0;
258}
259
260/* ----- end of gpio a chip ---------------------------------------------- */
261
262/* ----- begin of gipo b chip -------------------------------------------- */
263
264static int vprbrd_gpiob_setdir(struct vprbrd *vb, unsigned offset,
265	unsigned dir)
266{
267	struct vprbrd_gpiob_msg *gbmsg = (struct vprbrd_gpiob_msg *)vb->buf;
268	int ret;
269
270	gbmsg->cmd = VPRBRD_GPIOB_CMD_SETDIR;
271	gbmsg->val = cpu_to_be16(dir << offset);
272	gbmsg->mask = cpu_to_be16(0x0001 << offset);
273
274	ret = usb_control_msg(vb->usb_dev, usb_sndctrlpipe(vb->usb_dev, 0),
275		VPRBRD_USB_REQUEST_GPIOB, VPRBRD_USB_TYPE_OUT, 0x0000,
276		0x0000, gbmsg, sizeof(struct vprbrd_gpiob_msg),
277		VPRBRD_USB_TIMEOUT_MS);
278
279	if (ret != sizeof(struct vprbrd_gpiob_msg))
280		return -EREMOTEIO;
281
282	return 0;
283}
284
285static int vprbrd_gpiob_get(struct gpio_chip *chip,
286		unsigned offset)
287{
288	int ret;
289	u16 val;
290	struct vprbrd_gpio *gpio =
291			container_of(chip, struct vprbrd_gpio, gpiob);
292	struct vprbrd *vb = gpio->vb;
293	struct vprbrd_gpiob_msg *gbmsg = (struct vprbrd_gpiob_msg *)vb->buf;
294
295	/* if io is set to output, just return the saved value */
296	if (gpio->gpiob_out & (1 << offset))
297		return gpio->gpiob_val & (1 << offset);
298
299	mutex_lock(&vb->lock);
300
301	ret = usb_control_msg(vb->usb_dev, usb_rcvctrlpipe(vb->usb_dev, 0),
302		VPRBRD_USB_REQUEST_GPIOB, VPRBRD_USB_TYPE_IN, 0x0000,
303		0x0000, gbmsg,	sizeof(struct vprbrd_gpiob_msg),
304		VPRBRD_USB_TIMEOUT_MS);
305	val = gbmsg->val;
306
307	mutex_unlock(&vb->lock);
308
309	if (ret != sizeof(struct vprbrd_gpiob_msg))
310		return ret;
311
312	/* cache the read values */
313	gpio->gpiob_val = be16_to_cpu(val);
314
315	return (gpio->gpiob_val >> offset) & 0x1;
316}
317
318static void vprbrd_gpiob_set(struct gpio_chip *chip,
319		unsigned offset, int value)
320{
321	int ret;
322	struct vprbrd_gpio *gpio =
323			container_of(chip, struct vprbrd_gpio, gpiob);
324	struct vprbrd *vb = gpio->vb;
325	struct vprbrd_gpiob_msg *gbmsg = (struct vprbrd_gpiob_msg *)vb->buf;
326
327	if (gpio->gpiob_out & (1 << offset)) {
328		if (value)
329			gpio->gpiob_val |= (1 << offset);
330		else
331			gpio->gpiob_val &= ~(1 << offset);
332
333		mutex_lock(&vb->lock);
334
335		gbmsg->cmd = VPRBRD_GPIOB_CMD_SETVAL;
336		gbmsg->val = cpu_to_be16(value << offset);
337		gbmsg->mask = cpu_to_be16(0x0001 << offset);
338
339		ret = usb_control_msg(vb->usb_dev,
340			usb_sndctrlpipe(vb->usb_dev, 0),
341			VPRBRD_USB_REQUEST_GPIOB, VPRBRD_USB_TYPE_OUT,
342			0x0000,	0x0000, gbmsg,
343			sizeof(struct vprbrd_gpiob_msg), VPRBRD_USB_TIMEOUT_MS);
344
345		mutex_unlock(&vb->lock);
346
347		if (ret != sizeof(struct vprbrd_gpiob_msg))
348			dev_err(chip->dev, "usb error setting pin value\n");
349	}
350}
351
352static int vprbrd_gpiob_direction_input(struct gpio_chip *chip,
353			unsigned offset)
354{
355	int ret;
356	struct vprbrd_gpio *gpio =
357			container_of(chip, struct vprbrd_gpio, gpiob);
358	struct vprbrd *vb = gpio->vb;
359
360	gpio->gpiob_out &= ~(1 << offset);
361
362	mutex_lock(&vb->lock);
363
364	ret = vprbrd_gpiob_setdir(vb, offset, 0);
365
366	mutex_unlock(&vb->lock);
367
368	if (ret)
369		dev_err(chip->dev, "usb error setting pin to input\n");
370
371	return ret;
372}
373
374static int vprbrd_gpiob_direction_output(struct gpio_chip *chip,
375			unsigned offset, int value)
376{
377	int ret;
378	struct vprbrd_gpio *gpio =
379			container_of(chip, struct vprbrd_gpio, gpiob);
380	struct vprbrd *vb = gpio->vb;
381
382	gpio->gpiob_out |= (1 << offset);
383
384	mutex_lock(&vb->lock);
385
386	ret = vprbrd_gpiob_setdir(vb, offset, 1);
387	if (ret)
388		dev_err(chip->dev, "usb error setting pin to output\n");
389
390	mutex_unlock(&vb->lock);
391
392	vprbrd_gpiob_set(chip, offset, value);
393
394	return ret;
395}
396
397/* ----- end of gpio b chip ---------------------------------------------- */
398
399static int vprbrd_gpio_probe(struct platform_device *pdev)
400{
401	struct vprbrd *vb = dev_get_drvdata(pdev->dev.parent);
402	struct vprbrd_gpio *vb_gpio;
403	int ret;
404
405	vb_gpio = devm_kzalloc(&pdev->dev, sizeof(*vb_gpio), GFP_KERNEL);
406	if (vb_gpio == NULL)
407		return -ENOMEM;
408
409	vb_gpio->vb = vb;
410	/* registering gpio a */
411	vb_gpio->gpioa.label = "viperboard gpio a";
412	vb_gpio->gpioa.dev = &pdev->dev;
413	vb_gpio->gpioa.owner = THIS_MODULE;
414	vb_gpio->gpioa.base = -1;
415	vb_gpio->gpioa.ngpio = 16;
416	vb_gpio->gpioa.can_sleep = true;
417	vb_gpio->gpioa.set = vprbrd_gpioa_set;
418	vb_gpio->gpioa.get = vprbrd_gpioa_get;
419	vb_gpio->gpioa.direction_input = vprbrd_gpioa_direction_input;
420	vb_gpio->gpioa.direction_output = vprbrd_gpioa_direction_output;
421	ret = gpiochip_add(&vb_gpio->gpioa);
422	if (ret < 0) {
423		dev_err(vb_gpio->gpioa.dev, "could not add gpio a");
424		goto err_gpioa;
425	}
426
427	/* registering gpio b */
428	vb_gpio->gpiob.label = "viperboard gpio b";
429	vb_gpio->gpiob.dev = &pdev->dev;
430	vb_gpio->gpiob.owner = THIS_MODULE;
431	vb_gpio->gpiob.base = -1;
432	vb_gpio->gpiob.ngpio = 16;
433	vb_gpio->gpiob.can_sleep = true;
434	vb_gpio->gpiob.set = vprbrd_gpiob_set;
435	vb_gpio->gpiob.get = vprbrd_gpiob_get;
436	vb_gpio->gpiob.direction_input = vprbrd_gpiob_direction_input;
437	vb_gpio->gpiob.direction_output = vprbrd_gpiob_direction_output;
438	ret = gpiochip_add(&vb_gpio->gpiob);
439	if (ret < 0) {
440		dev_err(vb_gpio->gpiob.dev, "could not add gpio b");
441		goto err_gpiob;
442	}
443
444	platform_set_drvdata(pdev, vb_gpio);
445
446	return ret;
447
448err_gpiob:
449	gpiochip_remove(&vb_gpio->gpioa);
450
451err_gpioa:
452	return ret;
453}
454
455static int vprbrd_gpio_remove(struct platform_device *pdev)
456{
457	struct vprbrd_gpio *vb_gpio = platform_get_drvdata(pdev);
458
459	gpiochip_remove(&vb_gpio->gpiob);
460
461	return 0;
462}
463
464static struct platform_driver vprbrd_gpio_driver = {
465	.driver.name	= "viperboard-gpio",
466	.driver.owner	= THIS_MODULE,
467	.probe		= vprbrd_gpio_probe,
468	.remove		= vprbrd_gpio_remove,
469};
470
471static int __init vprbrd_gpio_init(void)
472{
473	switch (gpioa_freq) {
474	case 1000000:
475		gpioa_clk = VPRBRD_GPIOA_CLK_1MHZ;
476		break;
477	case 100000:
478		gpioa_clk = VPRBRD_GPIOA_CLK_100KHZ;
479		break;
480	case 10000:
481		gpioa_clk = VPRBRD_GPIOA_CLK_10KHZ;
482		break;
483	case 1000:
484		gpioa_clk = VPRBRD_GPIOA_CLK_1KHZ;
485		break;
486	case 100:
487		gpioa_clk = VPRBRD_GPIOA_CLK_100HZ;
488		break;
489	case 10:
490		gpioa_clk = VPRBRD_GPIOA_CLK_10HZ;
491		break;
492	default:
493		pr_warn("invalid gpioa_freq (%d)\n", gpioa_freq);
494		gpioa_clk = VPRBRD_GPIOA_CLK_1KHZ;
495	}
496
497	return platform_driver_register(&vprbrd_gpio_driver);
498}
499subsys_initcall(vprbrd_gpio_init);
500
501static void __exit vprbrd_gpio_exit(void)
502{
503	platform_driver_unregister(&vprbrd_gpio_driver);
504}
505module_exit(vprbrd_gpio_exit);
506
507MODULE_AUTHOR("Lars Poeschel <poeschel@lemonage.de>");
508MODULE_DESCRIPTION("GPIO driver for Nano River Techs Viperboard");
509MODULE_LICENSE("GPL");
510MODULE_ALIAS("platform:viperboard-gpio");
511