USB: convert some miscellanies drivers to use module_usb_driver()
[linux-2.6.git] / drivers / i2c / busses / i2c-tiny-usb.c
1 /*
2  * driver for the i2c-tiny-usb adapter - 1.0
3  * http://www.harbaum.org/till/i2c_tiny_usb
4  *
5  * Copyright (C) 2006-2007 Till Harbaum (Till@Harbaum.org)
6  *
7  * This program is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU General Public License as
9  * published by the Free Software Foundation, version 2.
10  *
11  */
12
13 #include <linux/kernel.h>
14 #include <linux/errno.h>
15 #include <linux/module.h>
16 #include <linux/slab.h>
17 #include <linux/types.h>
18
19 /* include interfaces to usb layer */
20 #include <linux/usb.h>
21
22 /* include interface to i2c layer */
23 #include <linux/i2c.h>
24
25 /* commands via USB, must match command ids in the firmware */
26 #define CMD_ECHO                0
27 #define CMD_GET_FUNC            1
28 #define CMD_SET_DELAY           2
29 #define CMD_GET_STATUS          3
30
31 #define CMD_I2C_IO              4
32 #define CMD_I2C_IO_BEGIN        (1<<0)
33 #define CMD_I2C_IO_END          (1<<1)
34
35 /* i2c bit delay, default is 10us -> 100kHz max
36    (in practice, due to additional delays in the i2c bitbanging
37    code this results in a i2c clock of about 50kHz) */
38 static unsigned short delay = 10;
39 module_param(delay, ushort, 0);
40 MODULE_PARM_DESC(delay, "bit delay in microseconds "
41                  "(default is 10us for 100kHz max)");
42
43 static int usb_read(struct i2c_adapter *adapter, int cmd,
44                     int value, int index, void *data, int len);
45
46 static int usb_write(struct i2c_adapter *adapter, int cmd,
47                      int value, int index, void *data, int len);
48
49 /* ----- begin of i2c layer ---------------------------------------------- */
50
51 #define STATUS_IDLE             0
52 #define STATUS_ADDRESS_ACK      1
53 #define STATUS_ADDRESS_NAK      2
54
55 static int usb_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, int num)
56 {
57         unsigned char status;
58         struct i2c_msg *pmsg;
59         int i;
60
61         dev_dbg(&adapter->dev, "master xfer %d messages:\n", num);
62
63         for (i = 0 ; i < num ; i++) {
64                 int cmd = CMD_I2C_IO;
65
66                 if (i == 0)
67                         cmd |= CMD_I2C_IO_BEGIN;
68
69                 if (i == num-1)
70                         cmd |= CMD_I2C_IO_END;
71
72                 pmsg = &msgs[i];
73
74                 dev_dbg(&adapter->dev,
75                         "  %d: %s (flags %d) %d bytes to 0x%02x\n",
76                         i, pmsg->flags & I2C_M_RD ? "read" : "write",
77                         pmsg->flags, pmsg->len, pmsg->addr);
78
79                 /* and directly send the message */
80                 if (pmsg->flags & I2C_M_RD) {
81                         /* read data */
82                         if (usb_read(adapter, cmd,
83                                      pmsg->flags, pmsg->addr,
84                                      pmsg->buf, pmsg->len) != pmsg->len) {
85                                 dev_err(&adapter->dev,
86                                         "failure reading data\n");
87                                 return -EREMOTEIO;
88                         }
89                 } else {
90                         /* write data */
91                         if (usb_write(adapter, cmd,
92                                       pmsg->flags, pmsg->addr,
93                                       pmsg->buf, pmsg->len) != pmsg->len) {
94                                 dev_err(&adapter->dev,
95                                         "failure writing data\n");
96                                 return -EREMOTEIO;
97                         }
98                 }
99
100                 /* read status */
101                 if (usb_read(adapter, CMD_GET_STATUS, 0, 0, &status, 1) != 1) {
102                         dev_err(&adapter->dev, "failure reading status\n");
103                         return -EREMOTEIO;
104                 }
105
106                 dev_dbg(&adapter->dev, "  status = %d\n", status);
107                 if (status == STATUS_ADDRESS_NAK)
108                         return -EREMOTEIO;
109         }
110
111         return i;
112 }
113
114 static u32 usb_func(struct i2c_adapter *adapter)
115 {
116         __le32 func;
117
118         /* get functionality from adapter */
119         if (usb_read(adapter, CMD_GET_FUNC, 0, 0, &func, sizeof(func)) !=
120             sizeof(func)) {
121                 dev_err(&adapter->dev, "failure reading functionality\n");
122                 return 0;
123         }
124
125         return le32_to_cpu(func);
126 }
127
128 /* This is the actual algorithm we define */
129 static const struct i2c_algorithm usb_algorithm = {
130         .master_xfer    = usb_xfer,
131         .functionality  = usb_func,
132 };
133
134 /* ----- end of i2c layer ------------------------------------------------ */
135
136 /* ----- begin of usb layer ---------------------------------------------- */
137
138 /*
139  * Initially the usb i2c interface uses a vid/pid pair donated by
140  * Future Technology Devices International Ltd., later a pair was
141  * bought from EZPrototypes
142  */
143 static const struct usb_device_id i2c_tiny_usb_table[] = {
144         { USB_DEVICE(0x0403, 0xc631) },   /* FTDI */
145         { USB_DEVICE(0x1c40, 0x0534) },   /* EZPrototypes */
146         { }                               /* Terminating entry */
147 };
148
149 MODULE_DEVICE_TABLE(usb, i2c_tiny_usb_table);
150
151 /* Structure to hold all of our device specific stuff */
152 struct i2c_tiny_usb {
153         struct usb_device *usb_dev; /* the usb device for this device */
154         struct usb_interface *interface; /* the interface for this device */
155         struct i2c_adapter adapter; /* i2c related things */
156 };
157
158 static int usb_read(struct i2c_adapter *adapter, int cmd,
159                     int value, int index, void *data, int len)
160 {
161         struct i2c_tiny_usb *dev = (struct i2c_tiny_usb *)adapter->algo_data;
162
163         /* do control transfer */
164         return usb_control_msg(dev->usb_dev, usb_rcvctrlpipe(dev->usb_dev, 0),
165                                cmd, USB_TYPE_VENDOR | USB_RECIP_INTERFACE |
166                                USB_DIR_IN, value, index, data, len, 2000);
167 }
168
169 static int usb_write(struct i2c_adapter *adapter, int cmd,
170                      int value, int index, void *data, int len)
171 {
172         struct i2c_tiny_usb *dev = (struct i2c_tiny_usb *)adapter->algo_data;
173
174         /* do control transfer */
175         return usb_control_msg(dev->usb_dev, usb_sndctrlpipe(dev->usb_dev, 0),
176                                cmd, USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
177                                value, index, data, len, 2000);
178 }
179
180 static void i2c_tiny_usb_free(struct i2c_tiny_usb *dev)
181 {
182         usb_put_dev(dev->usb_dev);
183         kfree(dev);
184 }
185
186 static int i2c_tiny_usb_probe(struct usb_interface *interface,
187                               const struct usb_device_id *id)
188 {
189         struct i2c_tiny_usb *dev;
190         int retval = -ENOMEM;
191         u16 version;
192
193         dev_dbg(&interface->dev, "probing usb device\n");
194
195         /* allocate memory for our device state and initialize it */
196         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
197         if (dev == NULL) {
198                 dev_err(&interface->dev, "Out of memory\n");
199                 goto error;
200         }
201
202         dev->usb_dev = usb_get_dev(interface_to_usbdev(interface));
203         dev->interface = interface;
204
205         /* save our data pointer in this interface device */
206         usb_set_intfdata(interface, dev);
207
208         version = le16_to_cpu(dev->usb_dev->descriptor.bcdDevice);
209         dev_info(&interface->dev,
210                  "version %x.%02x found at bus %03d address %03d\n",
211                  version >> 8, version & 0xff,
212                  dev->usb_dev->bus->busnum, dev->usb_dev->devnum);
213
214         /* setup i2c adapter description */
215         dev->adapter.owner = THIS_MODULE;
216         dev->adapter.class = I2C_CLASS_HWMON;
217         dev->adapter.algo = &usb_algorithm;
218         dev->adapter.algo_data = dev;
219         snprintf(dev->adapter.name, sizeof(dev->adapter.name),
220                  "i2c-tiny-usb at bus %03d device %03d",
221                  dev->usb_dev->bus->busnum, dev->usb_dev->devnum);
222
223         if (usb_write(&dev->adapter, CMD_SET_DELAY, delay, 0, NULL, 0) != 0) {
224                 dev_err(&dev->adapter.dev,
225                         "failure setting delay to %dus\n", delay);
226                 retval = -EIO;
227                 goto error;
228         }
229
230         dev->adapter.dev.parent = &dev->interface->dev;
231
232         /* and finally attach to i2c layer */
233         i2c_add_adapter(&dev->adapter);
234
235         /* inform user about successful attachment to i2c layer */
236         dev_info(&dev->adapter.dev, "connected i2c-tiny-usb device\n");
237
238         return 0;
239
240  error:
241         if (dev)
242                 i2c_tiny_usb_free(dev);
243
244         return retval;
245 }
246
247 static void i2c_tiny_usb_disconnect(struct usb_interface *interface)
248 {
249         struct i2c_tiny_usb *dev = usb_get_intfdata(interface);
250
251         i2c_del_adapter(&dev->adapter);
252         usb_set_intfdata(interface, NULL);
253         i2c_tiny_usb_free(dev);
254
255         dev_dbg(&interface->dev, "disconnected\n");
256 }
257
258 static struct usb_driver i2c_tiny_usb_driver = {
259         .name           = "i2c-tiny-usb",
260         .probe          = i2c_tiny_usb_probe,
261         .disconnect     = i2c_tiny_usb_disconnect,
262         .id_table       = i2c_tiny_usb_table,
263 };
264
265 module_usb_driver(i2c_tiny_usb_driver);
266
267 /* ----- end of usb layer ------------------------------------------------ */
268
269 MODULE_AUTHOR("Till Harbaum <Till@Harbaum.org>");
270 MODULE_DESCRIPTION("i2c-tiny-usb driver v1.0");
271 MODULE_LICENSE("GPL");