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 */
56static const 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		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);
111error:
112	return retval;
113}
114
115/* write port value */
116static 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);
142error:
143	return result < 0 ? result : count;
144}
145
146/* attribute callback handler (write) */
147static ssize_t port0_store(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) */
155static ssize_t port1_store(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 */
163static 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) */
181static ssize_t port0_show(struct device *dev,
182				 struct device_attribute *attr, char *buf)
183{
184	return read_port(dev, attr, buf, 0, CYPRESS_READ_PORT_ID0);
185}
186static DEVICE_ATTR_RW(port0);
187
188/* attribute callback handler (read) */
189static ssize_t port1_show(struct device *dev,
190				 struct device_attribute *attr, char *buf)
191{
192	return read_port(dev, attr, buf, 1, CYPRESS_READ_PORT_ID1);
193}
194static DEVICE_ATTR_RW(port1);
195
196static struct attribute *cypress_attrs[] = {
197	&dev_attr_port0.attr,
198	&dev_attr_port1.attr,
199	NULL,
200};
201ATTRIBUTE_GROUPS(cypress);
202
203static int cypress_probe(struct usb_interface *interface,
204			 const struct usb_device_id *id)
205{
206	struct cypress *dev;
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)
212		goto error_mem;
213
214	dev->udev = usb_get_dev(interface_to_usbdev(interface));
215
216	/* save our data pointer in this interface device */
217	usb_set_intfdata(interface, dev);
218
219	/* let the user know that the device is now attached */
220	dev_info(&interface->dev,
221		 "Cypress CY7C63xxx device now attached\n");
222	return 0;
223
224error_mem:
225	return retval;
226}
227
228static void cypress_disconnect(struct usb_interface *interface)
229{
230	struct cypress *dev;
231
232	dev = usb_get_intfdata(interface);
233
234	/* the intfdata can be set to NULL only after the
235	 * device files have been removed */
236	usb_set_intfdata(interface, NULL);
237
238	usb_put_dev(dev->udev);
239
240	dev_info(&interface->dev,
241		 "Cypress CY7C63xxx device now disconnected\n");
242
243	kfree(dev);
244}
245
246static struct usb_driver cypress_driver = {
247	.name = "cypress_cy7c63",
248	.probe = cypress_probe,
249	.disconnect = cypress_disconnect,
250	.id_table = cypress_table,
251	.dev_groups = cypress_groups,
252};
253
254module_usb_driver(cypress_driver);
255
256MODULE_AUTHOR(DRIVER_AUTHOR);
257MODULE_DESCRIPTION(DRIVER_DESC);
258
259MODULE_LICENSE("GPL");
260