1/*
2* cypress_cy7c63.c
3*
4* Copyright (c) 2006-2007 Oliver Bock (bock@tfh-berlin.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*	For up-to-date information please visit:
25*	http://www.obock.de/kernel/cypress
26*
27*	This program is free software; you can redistribute it and/or
28*	modify it under the terms of the GNU General Public License as
29*	published by the Free Software Foundation, version 2.
30*/
31
32#include <linux/module.h>
33#include <linux/kernel.h>
34#include <linux/slab.h>
35#include <linux/usb.h>
36
37#define DRIVER_AUTHOR		"Oliver Bock (bock@tfh-berlin.de)"
38#define DRIVER_DESC		"Cypress CY7C63xxx USB driver"
39
40#define CYPRESS_VENDOR_ID	0xa2c
41#define CYPRESS_PRODUCT_ID	0x8
42
43#define CYPRESS_READ_PORT	0x4
44#define CYPRESS_WRITE_PORT	0x5
45
46#define CYPRESS_READ_RAM	0x2
47#define CYPRESS_WRITE_RAM	0x3
48#define CYPRESS_READ_ROM	0x1
49
50#define CYPRESS_READ_PORT_ID0	0
51#define CYPRESS_WRITE_PORT_ID0	0
52#define CYPRESS_READ_PORT_ID1	0x2
53#define CYPRESS_WRITE_PORT_ID1	1
54
55#define CYPRESS_MAX_REQSIZE	8
56
57
58/* table of devices that work with this driver */
59static const struct usb_device_id cypress_table[] = {
60	{ USB_DEVICE(CYPRESS_VENDOR_ID, CYPRESS_PRODUCT_ID) },
61	{ }
62};
63MODULE_DEVICE_TABLE(usb, cypress_table);
64
65/* structure to hold all of our device specific stuff */
66struct cypress {
67	struct usb_device *	udev;
68	unsigned char		port[2];
69};
70
71/* used to send usb control messages to device */
72static int vendor_command(struct cypress *dev, unsigned char request,
73			  unsigned char address, unsigned char data)
74{
75	int retval = 0;
76	unsigned int pipe;
77	unsigned char *iobuf;
78
79	/* allocate some memory for the i/o buffer*/
80	iobuf = kzalloc(CYPRESS_MAX_REQSIZE, GFP_KERNEL);
81	if (!iobuf) {
82		dev_err(&dev->udev->dev, "Out of memory!\n");
83		retval = -ENOMEM;
84		goto error;
85	}
86
87	dev_dbg(&dev->udev->dev, "Sending usb_control_msg (data: %d)\n", data);
88
89	/* prepare usb control message and send it upstream */
90	pipe = usb_rcvctrlpipe(dev->udev, 0);
91	retval = usb_control_msg(dev->udev, pipe, request,
92				 USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_OTHER,
93				 address, data, iobuf, CYPRESS_MAX_REQSIZE,
94				 USB_CTRL_GET_TIMEOUT);
95
96	/* store returned data (more READs to be added) */
97	switch (request) {
98		case CYPRESS_READ_PORT:
99			if (address == CYPRESS_READ_PORT_ID0) {
100				dev->port[0] = iobuf[1];
101				dev_dbg(&dev->udev->dev,
102					"READ_PORT0 returned: %d\n",
103					dev->port[0]);
104			}
105			else if (address == CYPRESS_READ_PORT_ID1) {
106				dev->port[1] = iobuf[1];
107				dev_dbg(&dev->udev->dev,
108					"READ_PORT1 returned: %d\n",
109					dev->port[1]);
110			}
111			break;
112	}
113
114	kfree(iobuf);
115error:
116	return retval;
117}
118
119/* write port value */
120static ssize_t write_port(struct device *dev, struct device_attribute *attr,
121			  const char *buf, size_t count,
122			  int port_num, int write_id)
123{
124	int value = -1;
125	int result = 0;
126
127	struct usb_interface *intf = to_usb_interface(dev);
128	struct cypress *cyp = usb_get_intfdata(intf);
129
130	dev_dbg(&cyp->udev->dev, "WRITE_PORT%d called\n", port_num);
131
132	/* validate input data */
133	if (sscanf(buf, "%d", &value) < 1) {
134		result = -EINVAL;
135		goto error;
136	}
137	if (value < 0 || value > 255) {
138		result = -EINVAL;
139		goto error;
140	}
141
142	result = vendor_command(cyp, CYPRESS_WRITE_PORT, write_id,
143				(unsigned char)value);
144
145	dev_dbg(&cyp->udev->dev, "Result of vendor_command: %d\n\n", result);
146error:
147	return result < 0 ? result : count;
148}
149
150/* attribute callback handler (write) */
151static ssize_t set_port0_handler(struct device *dev,
152				 struct device_attribute *attr,
153				 const char *buf, size_t count)
154{
155	return write_port(dev, attr, buf, count, 0, CYPRESS_WRITE_PORT_ID0);
156}
157
158/* attribute callback handler (write) */
159static ssize_t set_port1_handler(struct device *dev,
160				 struct device_attribute *attr,
161				 const char *buf, size_t count)
162{
163	return write_port(dev, attr, buf, count, 1, CYPRESS_WRITE_PORT_ID1);
164}
165
166/* read port value */
167static ssize_t read_port(struct device *dev, struct device_attribute *attr,
168			 char *buf, int port_num, int read_id)
169{
170	int result = 0;
171
172	struct usb_interface *intf = to_usb_interface(dev);
173	struct cypress *cyp = usb_get_intfdata(intf);
174
175	dev_dbg(&cyp->udev->dev, "READ_PORT%d called\n", port_num);
176
177	result = vendor_command(cyp, CYPRESS_READ_PORT, read_id, 0);
178
179	dev_dbg(&cyp->udev->dev, "Result of vendor_command: %d\n\n", result);
180
181	return sprintf(buf, "%d", cyp->port[port_num]);
182}
183
184/* attribute callback handler (read) */
185static ssize_t get_port0_handler(struct device *dev,
186				 struct device_attribute *attr, char *buf)
187{
188	return read_port(dev, attr, buf, 0, CYPRESS_READ_PORT_ID0);
189}
190
191/* attribute callback handler (read) */
192static ssize_t get_port1_handler(struct device *dev,
193				 struct device_attribute *attr, char *buf)
194{
195	return read_port(dev, attr, buf, 1, CYPRESS_READ_PORT_ID1);
196}
197
198static DEVICE_ATTR(port0, S_IRUGO | S_IWUSR, get_port0_handler, set_port0_handler);
199
200static DEVICE_ATTR(port1, S_IRUGO | S_IWUSR, get_port1_handler, set_port1_handler);
201
202
203static int cypress_probe(struct usb_interface *interface,
204			 const struct usb_device_id *id)
205{
206	struct cypress *dev = NULL;
207	int retval = -ENOMEM;
208
209	/* allocate memory for our device state and initialize it */
210	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
211	if (dev == NULL) {
212		dev_err(&interface->dev, "Out of memory!\n");
213		goto error_mem;
214	}
215
216	dev->udev = usb_get_dev(interface_to_usbdev(interface));
217
218	/* save our data pointer in this interface device */
219	usb_set_intfdata(interface, dev);
220
221	/* create device attribute files */
222	retval = device_create_file(&interface->dev, &dev_attr_port0);
223	if (retval)
224		goto error;
225	retval = device_create_file(&interface->dev, &dev_attr_port1);
226	if (retval)
227		goto error;
228
229	/* let the user know that the device is now attached */
230	dev_info(&interface->dev,
231		 "Cypress CY7C63xxx device now attached\n");
232	return 0;
233
234error:
235	device_remove_file(&interface->dev, &dev_attr_port0);
236	device_remove_file(&interface->dev, &dev_attr_port1);
237	usb_set_intfdata(interface, NULL);
238	usb_put_dev(dev->udev);
239	kfree(dev);
240
241error_mem:
242	return retval;
243}
244
245static void cypress_disconnect(struct usb_interface *interface)
246{
247	struct cypress *dev;
248
249	dev = usb_get_intfdata(interface);
250
251	/* remove device attribute files */
252	device_remove_file(&interface->dev, &dev_attr_port0);
253	device_remove_file(&interface->dev, &dev_attr_port1);
254	/* the intfdata can be set to NULL only after the
255	 * device files have been removed */
256	usb_set_intfdata(interface, NULL);
257
258	usb_put_dev(dev->udev);
259
260	dev_info(&interface->dev,
261		 "Cypress CY7C63xxx device now disconnected\n");
262
263	kfree(dev);
264}
265
266static struct usb_driver cypress_driver = {
267	.name = "cypress_cy7c63",
268	.probe = cypress_probe,
269	.disconnect = cypress_disconnect,
270	.id_table = cypress_table,
271};
272
273module_usb_driver(cypress_driver);
274
275MODULE_AUTHOR(DRIVER_AUTHOR);
276MODULE_DESCRIPTION(DRIVER_DESC);
277
278MODULE_LICENSE("GPL");
279