xref: /openbmc/linux/drivers/usb/misc/cypress_cy7c63.c (revision 96de0e252cedffad61b3cb5e05662c591898e69a)
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 */
56 static struct usb_device_id cypress_table [] = {
57 	{ USB_DEVICE(CYPRESS_VENDOR_ID, CYPRESS_PRODUCT_ID) },
58 	{ }
59 };
60 MODULE_DEVICE_TABLE(usb, cypress_table);
61 
62 /* structure to hold all of our device specific stuff */
63 struct cypress {
64 	struct usb_device *	udev;
65 	unsigned char		port[2];
66 };
67 
68 /* used to send usb control messages to device */
69 static 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);
112 error:
113 	return retval;
114 }
115 
116 /* write port value */
117 static 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);
143 error:
144 	return result < 0 ? result : count;
145 }
146 
147 /* attribute callback handler (write) */
148 static 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) */
156 static 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 */
164 static 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) */
182 static 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) */
189 static 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 
195 static DEVICE_ATTR(port0, S_IWUGO | S_IRUGO,
196 		   get_port0_handler, set_port0_handler);
197 
198 static DEVICE_ATTR(port1, S_IWUGO | S_IRUGO,
199 		   get_port1_handler, set_port1_handler);
200 
201 
202 static 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 
233 error:
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 
240 error_mem:
241 	return retval;
242 }
243 
244 static 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 
265 static struct usb_driver cypress_driver = {
266 	.name = "cypress_cy7c63",
267 	.probe = cypress_probe,
268 	.disconnect = cypress_disconnect,
269 	.id_table = cypress_table,
270 };
271 
272 static 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 
285 static void __exit cypress_exit(void)
286 {
287 	/* deregister this driver with the USB subsystem */
288 	usb_deregister(&cypress_driver);
289 }
290 
291 module_init(cypress_init);
292 module_exit(cypress_exit);
293 
294 MODULE_AUTHOR(DRIVER_AUTHOR);
295 MODULE_DESCRIPTION(DRIVER_DESC);
296 
297 MODULE_LICENSE("GPL");
298