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 */
59 static const struct usb_device_id cypress_table[] = {
60 	{ USB_DEVICE(CYPRESS_VENDOR_ID, CYPRESS_PRODUCT_ID) },
61 	{ }
62 };
63 MODULE_DEVICE_TABLE(usb, cypress_table);
64 
65 /* structure to hold all of our device specific stuff */
66 struct cypress {
67 	struct usb_device *	udev;
68 	unsigned char		port[2];
69 };
70 
71 /* used to send usb control messages to device */
72 static 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);
115 error:
116 	return retval;
117 }
118 
119 /* write port value */
120 static 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);
146 error:
147 	return result < 0 ? result : count;
148 }
149 
150 /* attribute callback handler (write) */
151 static 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) */
159 static 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 */
167 static 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) */
185 static 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) */
192 static 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 
198 static DEVICE_ATTR(port0, S_IRUGO | S_IWUSR, get_port0_handler, set_port0_handler);
199 
200 static DEVICE_ATTR(port1, S_IRUGO | S_IWUSR, get_port1_handler, set_port1_handler);
201 
202 
203 static 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 
234 error:
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 
241 error_mem:
242 	return retval;
243 }
244 
245 static 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 
266 static struct usb_driver cypress_driver = {
267 	.name = "cypress_cy7c63",
268 	.probe = cypress_probe,
269 	.disconnect = cypress_disconnect,
270 	.id_table = cypress_table,
271 };
272 
273 module_usb_driver(cypress_driver);
274 
275 MODULE_AUTHOR(DRIVER_AUTHOR);
276 MODULE_DESCRIPTION(DRIVER_DESC);
277 
278 MODULE_LICENSE("GPL");
279