1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * cypress_cy7c63.c
4 *
5 * Copyright (c) 2006-2007 Oliver Bock (bock@tfh-berlin.de)
6 *
7 *	This driver is based on the Cypress USB Driver by Marcus Maul
8 *	(cyport) and the 2.0 version of Greg Kroah-Hartman's
9 *	USB Skeleton driver.
10 *
11 *	This is a generic driver for the Cypress CY7C63xxx family.
12 *	For the time being it enables you to read from and write to
13 *	the single I/O ports of the device.
14 *
15 *	Supported vendors:	AK Modul-Bus Computer GmbH
16 *				(Firmware "Port-Chip")
17 *
18 *	Supported devices:	CY7C63001A-PC
19 *				CY7C63001C-PXC
20 *				CY7C63001C-SXC
21 *
22 *	Supported functions:	Read/Write Ports
23 *
24 *
25 *	For up-to-date information please visit:
26 *	http://www.obock.de/kernel/cypress
27 */
28 
29 #include <linux/module.h>
30 #include <linux/kernel.h>
31 #include <linux/slab.h>
32 #include <linux/usb.h>
33 
34 #define DRIVER_AUTHOR		"Oliver Bock (bock@tfh-berlin.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 const 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 		retval = -ENOMEM;
80 		goto error;
81 	}
82 
83 	dev_dbg(&dev->udev->dev, "Sending usb_control_msg (data: %d)\n", data);
84 
85 	/* prepare usb control message and send it upstream */
86 	pipe = usb_rcvctrlpipe(dev->udev, 0);
87 	retval = usb_control_msg(dev->udev, pipe, request,
88 				 USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_OTHER,
89 				 address, data, iobuf, CYPRESS_MAX_REQSIZE,
90 				 USB_CTRL_GET_TIMEOUT);
91 
92 	/* store returned data (more READs to be added) */
93 	switch (request) {
94 		case CYPRESS_READ_PORT:
95 			if (address == CYPRESS_READ_PORT_ID0) {
96 				dev->port[0] = iobuf[1];
97 				dev_dbg(&dev->udev->dev,
98 					"READ_PORT0 returned: %d\n",
99 					dev->port[0]);
100 			}
101 			else if (address == CYPRESS_READ_PORT_ID1) {
102 				dev->port[1] = iobuf[1];
103 				dev_dbg(&dev->udev->dev,
104 					"READ_PORT1 returned: %d\n",
105 					dev->port[1]);
106 			}
107 			break;
108 	}
109 
110 	kfree(iobuf);
111 error:
112 	return retval;
113 }
114 
115 /* write port value */
116 static ssize_t write_port(struct device *dev, struct device_attribute *attr,
117 			  const char *buf, size_t count,
118 			  int port_num, int write_id)
119 {
120 	int value = -1;
121 	int result = 0;
122 
123 	struct usb_interface *intf = to_usb_interface(dev);
124 	struct cypress *cyp = usb_get_intfdata(intf);
125 
126 	dev_dbg(&cyp->udev->dev, "WRITE_PORT%d called\n", port_num);
127 
128 	/* validate input data */
129 	if (sscanf(buf, "%d", &value) < 1) {
130 		result = -EINVAL;
131 		goto error;
132 	}
133 	if (value < 0 || value > 255) {
134 		result = -EINVAL;
135 		goto error;
136 	}
137 
138 	result = vendor_command(cyp, CYPRESS_WRITE_PORT, write_id,
139 				(unsigned char)value);
140 
141 	dev_dbg(&cyp->udev->dev, "Result of vendor_command: %d\n\n", result);
142 error:
143 	return result < 0 ? result : count;
144 }
145 
146 /* attribute callback handler (write) */
147 static ssize_t set_port0_handler(struct device *dev,
148 				 struct device_attribute *attr,
149 				 const char *buf, size_t count)
150 {
151 	return write_port(dev, attr, buf, count, 0, CYPRESS_WRITE_PORT_ID0);
152 }
153 
154 /* attribute callback handler (write) */
155 static ssize_t set_port1_handler(struct device *dev,
156 				 struct device_attribute *attr,
157 				 const char *buf, size_t count)
158 {
159 	return write_port(dev, attr, buf, count, 1, CYPRESS_WRITE_PORT_ID1);
160 }
161 
162 /* read port value */
163 static ssize_t read_port(struct device *dev, struct device_attribute *attr,
164 			 char *buf, int port_num, int read_id)
165 {
166 	int result = 0;
167 
168 	struct usb_interface *intf = to_usb_interface(dev);
169 	struct cypress *cyp = usb_get_intfdata(intf);
170 
171 	dev_dbg(&cyp->udev->dev, "READ_PORT%d called\n", port_num);
172 
173 	result = vendor_command(cyp, CYPRESS_READ_PORT, read_id, 0);
174 
175 	dev_dbg(&cyp->udev->dev, "Result of vendor_command: %d\n\n", result);
176 
177 	return sprintf(buf, "%d", cyp->port[port_num]);
178 }
179 
180 /* attribute callback handler (read) */
181 static ssize_t get_port0_handler(struct device *dev,
182 				 struct device_attribute *attr, char *buf)
183 {
184 	return read_port(dev, attr, buf, 0, CYPRESS_READ_PORT_ID0);
185 }
186 
187 /* attribute callback handler (read) */
188 static ssize_t get_port1_handler(struct device *dev,
189 				 struct device_attribute *attr, char *buf)
190 {
191 	return read_port(dev, attr, buf, 1, CYPRESS_READ_PORT_ID1);
192 }
193 
194 static DEVICE_ATTR(port0, S_IRUGO | S_IWUSR, get_port0_handler, set_port0_handler);
195 
196 static DEVICE_ATTR(port1, S_IRUGO | S_IWUSR, get_port1_handler, set_port1_handler);
197 
198 
199 static int cypress_probe(struct usb_interface *interface,
200 			 const struct usb_device_id *id)
201 {
202 	struct cypress *dev = NULL;
203 	int retval = -ENOMEM;
204 
205 	/* allocate memory for our device state and initialize it */
206 	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
207 	if (!dev)
208 		goto error_mem;
209 
210 	dev->udev = usb_get_dev(interface_to_usbdev(interface));
211 
212 	/* save our data pointer in this interface device */
213 	usb_set_intfdata(interface, dev);
214 
215 	/* create device attribute files */
216 	retval = device_create_file(&interface->dev, &dev_attr_port0);
217 	if (retval)
218 		goto error;
219 	retval = device_create_file(&interface->dev, &dev_attr_port1);
220 	if (retval)
221 		goto error;
222 
223 	/* let the user know that the device is now attached */
224 	dev_info(&interface->dev,
225 		 "Cypress CY7C63xxx device now attached\n");
226 	return 0;
227 
228 error:
229 	device_remove_file(&interface->dev, &dev_attr_port0);
230 	device_remove_file(&interface->dev, &dev_attr_port1);
231 	usb_set_intfdata(interface, NULL);
232 	usb_put_dev(dev->udev);
233 	kfree(dev);
234 
235 error_mem:
236 	return retval;
237 }
238 
239 static void cypress_disconnect(struct usb_interface *interface)
240 {
241 	struct cypress *dev;
242 
243 	dev = usb_get_intfdata(interface);
244 
245 	/* remove device attribute files */
246 	device_remove_file(&interface->dev, &dev_attr_port0);
247 	device_remove_file(&interface->dev, &dev_attr_port1);
248 	/* the intfdata can be set to NULL only after the
249 	 * device files have been removed */
250 	usb_set_intfdata(interface, NULL);
251 
252 	usb_put_dev(dev->udev);
253 
254 	dev_info(&interface->dev,
255 		 "Cypress CY7C63xxx device now disconnected\n");
256 
257 	kfree(dev);
258 }
259 
260 static struct usb_driver cypress_driver = {
261 	.name = "cypress_cy7c63",
262 	.probe = cypress_probe,
263 	.disconnect = cypress_disconnect,
264 	.id_table = cypress_table,
265 };
266 
267 module_usb_driver(cypress_driver);
268 
269 MODULE_AUTHOR(DRIVER_AUTHOR);
270 MODULE_DESCRIPTION(DRIVER_DESC);
271 
272 MODULE_LICENSE("GPL");
273