1// SPDX-License-Identifier: GPL-2.0+
2/*
3 *  Nano River Technologies viperboard GPIO lib driver
4 *
5 *  (C) 2012 by Lemonage GmbH
6 *  Author: Lars Poeschel <poeschel@lemonage.de>
7 *  All rights reserved.
8 */
9
10#include <linux/kernel.h>
11#include <linux/errno.h>
12#include <linux/module.h>
13#include <linux/slab.h>
14#include <linux/types.h>
15#include <linux/mutex.h>
16#include <linux/platform_device.h>
17#include <linux/usb.h>
18#include <linux/gpio/driver.h>
19
20#include <linux/mfd/viperboard.h>
21
22#define VPRBRD_GPIOA_CLK_1MHZ		0
23#define VPRBRD_GPIOA_CLK_100KHZ		1
24#define VPRBRD_GPIOA_CLK_10KHZ		2
25#define VPRBRD_GPIOA_CLK_1KHZ		3
26#define VPRBRD_GPIOA_CLK_100HZ		4
27#define VPRBRD_GPIOA_CLK_10HZ		5
28
29#define VPRBRD_GPIOA_FREQ_DEFAULT	1000
30
31#define VPRBRD_GPIOA_CMD_CONT		0x00
32#define VPRBRD_GPIOA_CMD_PULSE		0x01
33#define VPRBRD_GPIOA_CMD_PWM		0x02
34#define VPRBRD_GPIOA_CMD_SETOUT		0x03
35#define VPRBRD_GPIOA_CMD_SETIN		0x04
36#define VPRBRD_GPIOA_CMD_SETINT		0x05
37#define VPRBRD_GPIOA_CMD_GETIN		0x06
38
39#define VPRBRD_GPIOB_CMD_SETDIR		0x00
40#define VPRBRD_GPIOB_CMD_SETVAL		0x01
41
42struct vprbrd_gpioa_msg {
43	u8 cmd;
44	u8 clk;
45	u8 offset;
46	u8 t1;
47	u8 t2;
48	u8 invert;
49	u8 pwmlevel;
50	u8 outval;
51	u8 risefall;
52	u8 answer;
53	u8 __fill;
54} __packed;
55
56struct vprbrd_gpiob_msg {
57	u8 cmd;
58	u16 val;
59	u16 mask;
60} __packed;
61
62struct vprbrd_gpio {
63	struct gpio_chip gpioa; /* gpio a related things */
64	u32 gpioa_out;
65	u32 gpioa_val;
66	struct gpio_chip gpiob; /* gpio b related things */
67	u32 gpiob_out;
68	u32 gpiob_val;
69	struct vprbrd *vb;
70};
71
72/* gpioa sampling clock module parameter */
73static unsigned char gpioa_clk;
74static unsigned int gpioa_freq = VPRBRD_GPIOA_FREQ_DEFAULT;
75module_param(gpioa_freq, uint, 0);
76MODULE_PARM_DESC(gpioa_freq,
77	"gpio-a sampling freq in Hz (default is 1000Hz) valid values: 10, 100, 1000, 10000, 100000, 1000000");
78
79/* ----- begin of gipo a chip -------------------------------------------- */
80
81static int vprbrd_gpioa_get(struct gpio_chip *chip,
82		unsigned int offset)
83{
84	int ret, answer, error = 0;
85	struct vprbrd_gpio *gpio = gpiochip_get_data(chip);
86	struct vprbrd *vb = gpio->vb;
87	struct vprbrd_gpioa_msg *gamsg = (struct vprbrd_gpioa_msg *)vb->buf;
88
89	/* if io is set to output, just return the saved value */
90	if (gpio->gpioa_out & (1 << offset))
91		return !!(gpio->gpioa_val & (1 << offset));
92
93	mutex_lock(&vb->lock);
94
95	gamsg->cmd = VPRBRD_GPIOA_CMD_GETIN;
96	gamsg->clk = 0x00;
97	gamsg->offset = offset;
98	gamsg->t1 = 0x00;
99	gamsg->t2 = 0x00;
100	gamsg->invert = 0x00;
101	gamsg->pwmlevel = 0x00;
102	gamsg->outval = 0x00;
103	gamsg->risefall = 0x00;
104	gamsg->answer = 0x00;
105	gamsg->__fill = 0x00;
106
107	ret = usb_control_msg(vb->usb_dev, usb_sndctrlpipe(vb->usb_dev, 0),
108		VPRBRD_USB_REQUEST_GPIOA, VPRBRD_USB_TYPE_OUT, 0x0000,
109		0x0000, gamsg, sizeof(struct vprbrd_gpioa_msg),
110		VPRBRD_USB_TIMEOUT_MS);
111	if (ret != sizeof(struct vprbrd_gpioa_msg))
112		error = -EREMOTEIO;
113
114	ret = usb_control_msg(vb->usb_dev, usb_rcvctrlpipe(vb->usb_dev, 0),
115		VPRBRD_USB_REQUEST_GPIOA, VPRBRD_USB_TYPE_IN, 0x0000,
116		0x0000, gamsg, sizeof(struct vprbrd_gpioa_msg),
117		VPRBRD_USB_TIMEOUT_MS);
118	answer = gamsg->answer & 0x01;
119
120	mutex_unlock(&vb->lock);
121
122	if (ret != sizeof(struct vprbrd_gpioa_msg))
123		error = -EREMOTEIO;
124
125	if (error)
126		return error;
127
128	return answer;
129}
130
131static void vprbrd_gpioa_set(struct gpio_chip *chip,
132		unsigned int offset, int value)
133{
134	int ret;
135	struct vprbrd_gpio *gpio = gpiochip_get_data(chip);
136	struct vprbrd *vb = gpio->vb;
137	struct vprbrd_gpioa_msg *gamsg = (struct vprbrd_gpioa_msg *)vb->buf;
138
139	if (gpio->gpioa_out & (1 << offset)) {
140		if (value)
141			gpio->gpioa_val |= (1 << offset);
142		else
143			gpio->gpioa_val &= ~(1 << offset);
144
145		mutex_lock(&vb->lock);
146
147		gamsg->cmd = VPRBRD_GPIOA_CMD_SETOUT;
148		gamsg->clk = 0x00;
149		gamsg->offset = offset;
150		gamsg->t1 = 0x00;
151		gamsg->t2 = 0x00;
152		gamsg->invert = 0x00;
153		gamsg->pwmlevel = 0x00;
154		gamsg->outval = value;
155		gamsg->risefall = 0x00;
156		gamsg->answer = 0x00;
157		gamsg->__fill = 0x00;
158
159		ret = usb_control_msg(vb->usb_dev,
160			usb_sndctrlpipe(vb->usb_dev, 0),
161			VPRBRD_USB_REQUEST_GPIOA, VPRBRD_USB_TYPE_OUT,
162			0x0000,	0x0000, gamsg,
163			sizeof(struct vprbrd_gpioa_msg), VPRBRD_USB_TIMEOUT_MS);
164
165		mutex_unlock(&vb->lock);
166
167		if (ret != sizeof(struct vprbrd_gpioa_msg))
168			dev_err(chip->parent, "usb error setting pin value\n");
169	}
170}
171
172static int vprbrd_gpioa_direction_input(struct gpio_chip *chip,
173			unsigned int offset)
174{
175	int ret;
176	struct vprbrd_gpio *gpio = gpiochip_get_data(chip);
177	struct vprbrd *vb = gpio->vb;
178	struct vprbrd_gpioa_msg *gamsg = (struct vprbrd_gpioa_msg *)vb->buf;
179
180	gpio->gpioa_out &= ~(1 << offset);
181
182	mutex_lock(&vb->lock);
183
184	gamsg->cmd = VPRBRD_GPIOA_CMD_SETIN;
185	gamsg->clk = gpioa_clk;
186	gamsg->offset = offset;
187	gamsg->t1 = 0x00;
188	gamsg->t2 = 0x00;
189	gamsg->invert = 0x00;
190	gamsg->pwmlevel = 0x00;
191	gamsg->outval = 0x00;
192	gamsg->risefall = 0x00;
193	gamsg->answer = 0x00;
194	gamsg->__fill = 0x00;
195
196	ret = usb_control_msg(vb->usb_dev, usb_sndctrlpipe(vb->usb_dev, 0),
197		VPRBRD_USB_REQUEST_GPIOA, VPRBRD_USB_TYPE_OUT, 0x0000,
198		0x0000, gamsg, sizeof(struct vprbrd_gpioa_msg),
199		VPRBRD_USB_TIMEOUT_MS);
200
201	mutex_unlock(&vb->lock);
202
203	if (ret != sizeof(struct vprbrd_gpioa_msg))
204		return -EREMOTEIO;
205
206	return 0;
207}
208
209static int vprbrd_gpioa_direction_output(struct gpio_chip *chip,
210			unsigned int offset, int value)
211{
212	int ret;
213	struct vprbrd_gpio *gpio = gpiochip_get_data(chip);
214	struct vprbrd *vb = gpio->vb;
215	struct vprbrd_gpioa_msg *gamsg = (struct vprbrd_gpioa_msg *)vb->buf;
216
217	gpio->gpioa_out |= (1 << offset);
218	if (value)
219		gpio->gpioa_val |= (1 << offset);
220	else
221		gpio->gpioa_val &= ~(1 << offset);
222
223	mutex_lock(&vb->lock);
224
225	gamsg->cmd = VPRBRD_GPIOA_CMD_SETOUT;
226	gamsg->clk = 0x00;
227	gamsg->offset = offset;
228	gamsg->t1 = 0x00;
229	gamsg->t2 = 0x00;
230	gamsg->invert = 0x00;
231	gamsg->pwmlevel = 0x00;
232	gamsg->outval = value;
233	gamsg->risefall = 0x00;
234	gamsg->answer = 0x00;
235	gamsg->__fill = 0x00;
236
237	ret = usb_control_msg(vb->usb_dev, usb_sndctrlpipe(vb->usb_dev, 0),
238		VPRBRD_USB_REQUEST_GPIOA, VPRBRD_USB_TYPE_OUT, 0x0000,
239		0x0000, gamsg, sizeof(struct vprbrd_gpioa_msg),
240		VPRBRD_USB_TIMEOUT_MS);
241
242	mutex_unlock(&vb->lock);
243
244	if (ret != sizeof(struct vprbrd_gpioa_msg))
245		return -EREMOTEIO;
246
247	return 0;
248}
249
250/* ----- end of gpio a chip ---------------------------------------------- */
251
252/* ----- begin of gipo b chip -------------------------------------------- */
253
254static int vprbrd_gpiob_setdir(struct vprbrd *vb, unsigned int offset,
255	unsigned int dir)
256{
257	struct vprbrd_gpiob_msg *gbmsg = (struct vprbrd_gpiob_msg *)vb->buf;
258	int ret;
259
260	gbmsg->cmd = VPRBRD_GPIOB_CMD_SETDIR;
261	gbmsg->val = cpu_to_be16(dir << offset);
262	gbmsg->mask = cpu_to_be16(0x0001 << offset);
263
264	ret = usb_control_msg(vb->usb_dev, usb_sndctrlpipe(vb->usb_dev, 0),
265		VPRBRD_USB_REQUEST_GPIOB, VPRBRD_USB_TYPE_OUT, 0x0000,
266		0x0000, gbmsg, sizeof(struct vprbrd_gpiob_msg),
267		VPRBRD_USB_TIMEOUT_MS);
268
269	if (ret != sizeof(struct vprbrd_gpiob_msg))
270		return -EREMOTEIO;
271
272	return 0;
273}
274
275static int vprbrd_gpiob_get(struct gpio_chip *chip,
276		unsigned int offset)
277{
278	int ret;
279	u16 val;
280	struct vprbrd_gpio *gpio = gpiochip_get_data(chip);
281	struct vprbrd *vb = gpio->vb;
282	struct vprbrd_gpiob_msg *gbmsg = (struct vprbrd_gpiob_msg *)vb->buf;
283
284	/* if io is set to output, just return the saved value */
285	if (gpio->gpiob_out & (1 << offset))
286		return gpio->gpiob_val & (1 << offset);
287
288	mutex_lock(&vb->lock);
289
290	ret = usb_control_msg(vb->usb_dev, usb_rcvctrlpipe(vb->usb_dev, 0),
291		VPRBRD_USB_REQUEST_GPIOB, VPRBRD_USB_TYPE_IN, 0x0000,
292		0x0000, gbmsg,	sizeof(struct vprbrd_gpiob_msg),
293		VPRBRD_USB_TIMEOUT_MS);
294	val = gbmsg->val;
295
296	mutex_unlock(&vb->lock);
297
298	if (ret != sizeof(struct vprbrd_gpiob_msg))
299		return ret;
300
301	/* cache the read values */
302	gpio->gpiob_val = be16_to_cpu(val);
303
304	return (gpio->gpiob_val >> offset) & 0x1;
305}
306
307static void vprbrd_gpiob_set(struct gpio_chip *chip,
308		unsigned int offset, int value)
309{
310	int ret;
311	struct vprbrd_gpio *gpio = gpiochip_get_data(chip);
312	struct vprbrd *vb = gpio->vb;
313	struct vprbrd_gpiob_msg *gbmsg = (struct vprbrd_gpiob_msg *)vb->buf;
314
315	if (gpio->gpiob_out & (1 << offset)) {
316		if (value)
317			gpio->gpiob_val |= (1 << offset);
318		else
319			gpio->gpiob_val &= ~(1 << offset);
320
321		mutex_lock(&vb->lock);
322
323		gbmsg->cmd = VPRBRD_GPIOB_CMD_SETVAL;
324		gbmsg->val = cpu_to_be16(value << offset);
325		gbmsg->mask = cpu_to_be16(0x0001 << offset);
326
327		ret = usb_control_msg(vb->usb_dev,
328			usb_sndctrlpipe(vb->usb_dev, 0),
329			VPRBRD_USB_REQUEST_GPIOB, VPRBRD_USB_TYPE_OUT,
330			0x0000,	0x0000, gbmsg,
331			sizeof(struct vprbrd_gpiob_msg), VPRBRD_USB_TIMEOUT_MS);
332
333		mutex_unlock(&vb->lock);
334
335		if (ret != sizeof(struct vprbrd_gpiob_msg))
336			dev_err(chip->parent, "usb error setting pin value\n");
337	}
338}
339
340static int vprbrd_gpiob_direction_input(struct gpio_chip *chip,
341			unsigned int offset)
342{
343	int ret;
344	struct vprbrd_gpio *gpio = gpiochip_get_data(chip);
345	struct vprbrd *vb = gpio->vb;
346
347	gpio->gpiob_out &= ~(1 << offset);
348
349	mutex_lock(&vb->lock);
350
351	ret = vprbrd_gpiob_setdir(vb, offset, 0);
352
353	mutex_unlock(&vb->lock);
354
355	if (ret)
356		dev_err(chip->parent, "usb error setting pin to input\n");
357
358	return ret;
359}
360
361static int vprbrd_gpiob_direction_output(struct gpio_chip *chip,
362			unsigned int offset, int value)
363{
364	int ret;
365	struct vprbrd_gpio *gpio = gpiochip_get_data(chip);
366	struct vprbrd *vb = gpio->vb;
367
368	gpio->gpiob_out |= (1 << offset);
369
370	mutex_lock(&vb->lock);
371
372	ret = vprbrd_gpiob_setdir(vb, offset, 1);
373	if (ret)
374		dev_err(chip->parent, "usb error setting pin to output\n");
375
376	mutex_unlock(&vb->lock);
377
378	vprbrd_gpiob_set(chip, offset, value);
379
380	return ret;
381}
382
383/* ----- end of gpio b chip ---------------------------------------------- */
384
385static int vprbrd_gpio_probe(struct platform_device *pdev)
386{
387	struct vprbrd *vb = dev_get_drvdata(pdev->dev.parent);
388	struct vprbrd_gpio *vb_gpio;
389	int ret;
390
391	vb_gpio = devm_kzalloc(&pdev->dev, sizeof(*vb_gpio), GFP_KERNEL);
392	if (vb_gpio == NULL)
393		return -ENOMEM;
394
395	vb_gpio->vb = vb;
396	/* registering gpio a */
397	vb_gpio->gpioa.label = "viperboard gpio a";
398	vb_gpio->gpioa.parent = &pdev->dev;
399	vb_gpio->gpioa.owner = THIS_MODULE;
400	vb_gpio->gpioa.base = -1;
401	vb_gpio->gpioa.ngpio = 16;
402	vb_gpio->gpioa.can_sleep = true;
403	vb_gpio->gpioa.set = vprbrd_gpioa_set;
404	vb_gpio->gpioa.get = vprbrd_gpioa_get;
405	vb_gpio->gpioa.direction_input = vprbrd_gpioa_direction_input;
406	vb_gpio->gpioa.direction_output = vprbrd_gpioa_direction_output;
407
408	ret = devm_gpiochip_add_data(&pdev->dev, &vb_gpio->gpioa, vb_gpio);
409	if (ret < 0)
410		return ret;
411
412	/* registering gpio b */
413	vb_gpio->gpiob.label = "viperboard gpio b";
414	vb_gpio->gpiob.parent = &pdev->dev;
415	vb_gpio->gpiob.owner = THIS_MODULE;
416	vb_gpio->gpiob.base = -1;
417	vb_gpio->gpiob.ngpio = 16;
418	vb_gpio->gpiob.can_sleep = true;
419	vb_gpio->gpiob.set = vprbrd_gpiob_set;
420	vb_gpio->gpiob.get = vprbrd_gpiob_get;
421	vb_gpio->gpiob.direction_input = vprbrd_gpiob_direction_input;
422	vb_gpio->gpiob.direction_output = vprbrd_gpiob_direction_output;
423
424	return devm_gpiochip_add_data(&pdev->dev, &vb_gpio->gpiob, vb_gpio);
425}
426
427static struct platform_driver vprbrd_gpio_driver = {
428	.driver.name	= "viperboard-gpio",
429	.probe		= vprbrd_gpio_probe,
430};
431
432static int __init vprbrd_gpio_init(void)
433{
434	switch (gpioa_freq) {
435	case 1000000:
436		gpioa_clk = VPRBRD_GPIOA_CLK_1MHZ;
437		break;
438	case 100000:
439		gpioa_clk = VPRBRD_GPIOA_CLK_100KHZ;
440		break;
441	case 10000:
442		gpioa_clk = VPRBRD_GPIOA_CLK_10KHZ;
443		break;
444	case 1000:
445		gpioa_clk = VPRBRD_GPIOA_CLK_1KHZ;
446		break;
447	case 100:
448		gpioa_clk = VPRBRD_GPIOA_CLK_100HZ;
449		break;
450	case 10:
451		gpioa_clk = VPRBRD_GPIOA_CLK_10HZ;
452		break;
453	default:
454		pr_warn("invalid gpioa_freq (%d)\n", gpioa_freq);
455		gpioa_clk = VPRBRD_GPIOA_CLK_1KHZ;
456	}
457
458	return platform_driver_register(&vprbrd_gpio_driver);
459}
460subsys_initcall(vprbrd_gpio_init);
461
462static void __exit vprbrd_gpio_exit(void)
463{
464	platform_driver_unregister(&vprbrd_gpio_driver);
465}
466module_exit(vprbrd_gpio_exit);
467
468MODULE_AUTHOR("Lars Poeschel <poeschel@lemonage.de>");
469MODULE_DESCRIPTION("GPIO driver for Nano River Techs Viperboard");
470MODULE_LICENSE("GPL");
471MODULE_ALIAS("platform:viperboard-gpio");
472