1/*
2* cypress_cy7c63.c
3*
4* Copyright (c) 2006 Oliver Bock (o.bock@fh-wolfenbuettel.de)
5*
6*	This driver is based on the Cypress USB Driver by Marcus Maul
7*	(cyport) and the 2.0 version of Greg Kroah-Hartman's
8*	USB Skeleton driver.
9*
10*	This is a generic driver for the Cypress CY7C63xxx family.
11*	For the time being it enables you to read from and write to
12*	the single I/O ports of the device.
13*
14*	Supported vendors:	AK Modul-Bus Computer GmbH
15*				(Firmware "Port-Chip")
16*
17*	Supported devices:	CY7C63001A-PC
18*				CY7C63001C-PXC
19*				CY7C63001C-SXC
20*
21*	Supported functions:	Read/Write Ports
22*
23*
24*	This program is free software; you can redistribute it and/or
25*	modify it under the terms of the GNU General Public License as
26*	published by the Free Software Foundation, version 2.
27*/
28
29#include <linux/init.h>
30#include <linux/module.h>
31#include <linux/kernel.h>
32#include <linux/usb.h>
33
34#define DRIVER_AUTHOR		"Oliver Bock (o.bock@fh-wolfenbuettel.de)"
35#define DRIVER_DESC		"Cypress CY7C63xxx USB driver"
36
37#define CYPRESS_VENDOR_ID	0xa2c
38#define CYPRESS_PRODUCT_ID	0x8
39
40#define CYPRESS_READ_PORT	0x4
41#define CYPRESS_WRITE_PORT	0x5
42
43#define CYPRESS_READ_RAM	0x2
44#define CYPRESS_WRITE_RAM	0x3
45#define CYPRESS_READ_ROM	0x1
46
47#define CYPRESS_READ_PORT_ID0	0
48#define CYPRESS_WRITE_PORT_ID0	0
49#define CYPRESS_READ_PORT_ID1	0x2
50#define CYPRESS_WRITE_PORT_ID1	1
51
52#define CYPRESS_MAX_REQSIZE	8
53
54
55/* table of devices that work with this driver */
56static struct usb_device_id cypress_table [] = {
57	{ USB_DEVICE(CYPRESS_VENDOR_ID, CYPRESS_PRODUCT_ID) },
58	{ }
59};
60MODULE_DEVICE_TABLE(usb, cypress_table);
61
62/* structure to hold all of our device specific stuff */
63struct cypress {
64	struct usb_device *	udev;
65	unsigned char		port[2];
66};
67
68/* used to send usb control messages to device */
69static int vendor_command(struct cypress *dev, unsigned char request,
70			  unsigned char address, unsigned char data)
71{
72	int retval = 0;
73	unsigned int pipe;
74	unsigned char *iobuf;
75
76	/* allocate some memory for the i/o buffer*/
77	iobuf = kzalloc(CYPRESS_MAX_REQSIZE, GFP_KERNEL);
78	if (!iobuf) {
79		dev_err(&dev->udev->dev, "Out of memory!\n");
80		retval = -ENOMEM;
81		goto error;
82	}
83
84	dev_dbg(&dev->udev->dev, "Sending usb_control_msg (data: %d)\n", data);
85
86	/* prepare usb control message and send it upstream */
87	pipe = usb_rcvctrlpipe(dev->udev, 0);
88	retval = usb_control_msg(dev->udev, pipe, request,
89				 USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_OTHER,
90				 address, data, iobuf, CYPRESS_MAX_REQSIZE,
91				 USB_CTRL_GET_TIMEOUT);
92
93	/* store returned data (more READs to be added) */
94	switch (request) {
95		case CYPRESS_READ_PORT:
96			if (address == CYPRESS_READ_PORT_ID0) {
97				dev->port[0] = iobuf[1];
98				dev_dbg(&dev->udev->dev,
99					"READ_PORT0 returned: %d\n",
100					dev->port[0]);
101			}
102			else if (address == CYPRESS_READ_PORT_ID1) {
103				dev->port[1] = iobuf[1];
104				dev_dbg(&dev->udev->dev,
105					"READ_PORT1 returned: %d\n",
106					dev->port[1]);
107			}
108			break;
109	}
110
111	kfree(iobuf);
112error:
113	return retval;
114}
115
116/* write port value */
117static ssize_t write_port(struct device *dev, struct device_attribute *attr,
118			  const char *buf, size_t count,
119			  int port_num, int write_id)
120{
121	int value = -1;
122	int result = 0;
123
124	struct usb_interface *intf = to_usb_interface(dev);
125	struct cypress *cyp = usb_get_intfdata(intf);
126
127	dev_dbg(&cyp->udev->dev, "WRITE_PORT%d called\n", port_num);
128
129	/* validate input data */
130	if (sscanf(buf, "%d", &value) < 1) {
131		result = -EINVAL;
132		goto error;
133	}
134	if (value < 0 || value > 255) {
135		result = -EINVAL;
136		goto error;
137	}
138
139	result = vendor_command(cyp, CYPRESS_WRITE_PORT, write_id,
140				(unsigned char)value);
141
142	dev_dbg(&cyp->udev->dev, "Result of vendor_command: %d\n\n", result);
143error:
144	return result < 0 ? result : count;
145}
146
147/* attribute callback handler (write) */
148static ssize_t set_port0_handler(struct device *dev,
149				 struct device_attribute *attr,
150				 const char *buf, size_t count)
151{
152	return write_port(dev, attr, buf, count, 0, CYPRESS_WRITE_PORT_ID0);
153}
154
155/* attribute callback handler (write) */
156static ssize_t set_port1_handler(struct device *dev,
157				 struct device_attribute *attr,
158				 const char *buf, size_t count)
159{
160	return write_port(dev, attr, buf, count, 1, CYPRESS_WRITE_PORT_ID1);
161}
162
163/* read port value */
164static ssize_t read_port(struct device *dev, struct device_attribute *attr,
165			 char *buf, int port_num, int read_id)
166{
167	int result = 0;
168
169	struct usb_interface *intf = to_usb_interface(dev);
170	struct cypress *cyp = usb_get_intfdata(intf);
171
172	dev_dbg(&cyp->udev->dev, "READ_PORT%d called\n", port_num);
173
174	result = vendor_command(cyp, CYPRESS_READ_PORT, read_id, 0);
175
176	dev_dbg(&cyp->udev->dev, "Result of vendor_command: %d\n\n", result);
177
178	return sprintf(buf, "%d", cyp->port[port_num]);
179}
180
181/* attribute callback handler (read) */
182static ssize_t get_port0_handler(struct device *dev,
183				 struct device_attribute *attr, char *buf)
184{
185	return read_port(dev, attr, buf, 0, CYPRESS_READ_PORT_ID0);
186}
187
188/* attribute callback handler (read) */
189static ssize_t get_port1_handler(struct device *dev,
190				 struct device_attribute *attr, char *buf)
191{
192	return read_port(dev, attr, buf, 1, CYPRESS_READ_PORT_ID1);
193}
194
195static DEVICE_ATTR(port0, S_IWUGO | S_IRUGO,
196		   get_port0_handler, set_port0_handler);
197
198static DEVICE_ATTR(port1, S_IWUGO | S_IRUGO,
199		   get_port1_handler, set_port1_handler);
200
201
202static int cypress_probe(struct usb_interface *interface,
203			 const struct usb_device_id *id)
204{
205	struct cypress *dev = NULL;
206	int retval = -ENOMEM;
207
208	/* allocate memory for our device state and initialize it */
209	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
210	if (dev == NULL) {
211		dev_err(&interface->dev, "Out of memory!\n");
212		goto error_mem;
213	}
214
215	dev->udev = usb_get_dev(interface_to_usbdev(interface));
216
217	/* save our data pointer in this interface device */
218	usb_set_intfdata(interface, dev);
219
220	/* create device attribute files */
221	retval = device_create_file(&interface->dev, &dev_attr_port0);
222	if (retval)
223		goto error;
224	retval = device_create_file(&interface->dev, &dev_attr_port1);
225	if (retval)
226		goto error;
227
228	/* let the user know that the device is now attached */
229	dev_info(&interface->dev,
230		 "Cypress CY7C63xxx device now attached\n");
231	return 0;
232
233error:
234	device_remove_file(&interface->dev, &dev_attr_port0);
235	device_remove_file(&interface->dev, &dev_attr_port1);
236	usb_set_intfdata(interface, NULL);
237	usb_put_dev(dev->udev);
238	kfree(dev);
239
240error_mem:
241	return retval;
242}
243
244static void cypress_disconnect(struct usb_interface *interface)
245{
246	struct cypress *dev;
247
248	dev = usb_get_intfdata(interface);
249
250	/* remove device attribute files */
251	device_remove_file(&interface->dev, &dev_attr_port0);
252	device_remove_file(&interface->dev, &dev_attr_port1);
253	/* the intfdata can be set to NULL only after the
254	 * device files have been removed */
255	usb_set_intfdata(interface, NULL);
256
257	usb_put_dev(dev->udev);
258
259	dev_info(&interface->dev,
260		 "Cypress CY7C63xxx device now disconnected\n");
261
262	kfree(dev);
263}
264
265static struct usb_driver cypress_driver = {
266	.name = "cypress_cy7c63",
267	.probe = cypress_probe,
268	.disconnect = cypress_disconnect,
269	.id_table = cypress_table,
270};
271
272static int __init cypress_init(void)
273{
274	int result;
275
276	/* register this driver with the USB subsystem */
277	result = usb_register(&cypress_driver);
278	if (result) {
279		err("Function usb_register failed! Error number: %d\n", result);
280	}
281
282	return result;
283}
284
285static void __exit cypress_exit(void)
286{
287	/* deregister this driver with the USB subsystem */
288	usb_deregister(&cypress_driver);
289}
290
291module_init(cypress_init);
292module_exit(cypress_exit);
293
294MODULE_AUTHOR(DRIVER_AUTHOR);
295MODULE_DESCRIPTION(DRIVER_DESC);
296
297MODULE_LICENSE("GPL");
298