2 i2c-dev.c - i2c-bus driver, char device interface
4 Copyright (C) 1995-97 Simon G. Vogl
5 Copyright (C) 1998-99 Frodo Looijaard <frodol@dds.nl>
6 Copyright (C) 2003 Greg Kroah-Hartman <greg@kroah.com>
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the Free Software
20 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
23 /* Note that this is a complete rewrite of Simon Vogl's i2c-dev module.
24 But I have used so much of his original code and ideas that it seems
25 only fair to recognize him as co-author -- Frodo */
27 /* The I2C_RDWR ioctl code is written by Kolja Waschk <waschk@telos.de> */
29 #include <linux/kernel.h>
30 #include <linux/module.h>
32 #include <linux/slab.h>
33 #include <linux/smp_lock.h>
34 #include <linux/init.h>
35 #include <linux/i2c.h>
36 #include <linux/i2c-dev.h>
37 #include <asm/uaccess.h>
39 static struct i2c_client i2cdev_client_template;
43 struct i2c_adapter *adap;
44 struct class_device class_dev;
45 struct completion released; /* FIXME, we need a class_device_unregister() */
47 #define to_i2c_dev(d) container_of(d, struct i2c_dev, class_dev)
49 #define I2C_MINORS 256
50 static struct i2c_dev *i2c_dev_array[I2C_MINORS];
51 static DEFINE_SPINLOCK(i2c_dev_array_lock);
53 static struct i2c_dev *i2c_dev_get_by_minor(unsigned index)
55 struct i2c_dev *i2c_dev;
57 spin_lock(&i2c_dev_array_lock);
58 i2c_dev = i2c_dev_array[index];
59 spin_unlock(&i2c_dev_array_lock);
63 static struct i2c_dev *i2c_dev_get_by_adapter(struct i2c_adapter *adap)
65 struct i2c_dev *i2c_dev = NULL;
67 spin_lock(&i2c_dev_array_lock);
68 if ((i2c_dev_array[adap->nr]) &&
69 (i2c_dev_array[adap->nr]->adap == adap))
70 i2c_dev = i2c_dev_array[adap->nr];
71 spin_unlock(&i2c_dev_array_lock);
75 static struct i2c_dev *get_free_i2c_dev(struct i2c_adapter *adap)
77 struct i2c_dev *i2c_dev;
79 i2c_dev = kzalloc(sizeof(*i2c_dev), GFP_KERNEL);
81 return ERR_PTR(-ENOMEM);
83 spin_lock(&i2c_dev_array_lock);
84 if (i2c_dev_array[adap->nr]) {
85 spin_unlock(&i2c_dev_array_lock);
86 dev_err(&adap->dev, "i2c-dev already has a device assigned to this adapter\n");
89 i2c_dev->minor = adap->nr;
90 i2c_dev_array[adap->nr] = i2c_dev;
91 spin_unlock(&i2c_dev_array_lock);
95 return ERR_PTR(-ENODEV);
98 static void return_i2c_dev(struct i2c_dev *i2c_dev)
100 spin_lock(&i2c_dev_array_lock);
101 i2c_dev_array[i2c_dev->minor] = NULL;
102 spin_unlock(&i2c_dev_array_lock);
105 static ssize_t show_adapter_name(struct class_device *class_dev, char *buf)
107 struct i2c_dev *i2c_dev = to_i2c_dev(class_dev);
108 return sprintf(buf, "%s\n", i2c_dev->adap->name);
110 static CLASS_DEVICE_ATTR(name, S_IRUGO, show_adapter_name, NULL);
112 static ssize_t i2cdev_read (struct file *file, char __user *buf, size_t count,
118 struct i2c_client *client = (struct i2c_client *)file->private_data;
123 tmp = kmalloc(count,GFP_KERNEL);
127 pr_debug("i2c-dev: i2c-%d reading %zd bytes.\n",
128 iminor(file->f_dentry->d_inode), count);
130 ret = i2c_master_recv(client,tmp,count);
132 ret = copy_to_user(buf,tmp,count)?-EFAULT:ret;
137 static ssize_t i2cdev_write (struct file *file, const char __user *buf, size_t count,
142 struct i2c_client *client = (struct i2c_client *)file->private_data;
147 tmp = kmalloc(count,GFP_KERNEL);
150 if (copy_from_user(tmp,buf,count)) {
155 pr_debug("i2c-dev: i2c-%d writing %zd bytes.\n",
156 iminor(file->f_dentry->d_inode), count);
158 ret = i2c_master_send(client,tmp,count);
163 static int i2cdev_ioctl(struct inode *inode, struct file *file,
164 unsigned int cmd, unsigned long arg)
166 struct i2c_client *client = (struct i2c_client *)file->private_data;
167 struct i2c_rdwr_ioctl_data rdwr_arg;
168 struct i2c_smbus_ioctl_data data_arg;
169 union i2c_smbus_data temp;
170 struct i2c_msg *rdwr_pa;
171 u8 __user **data_ptrs;
175 dev_dbg(&client->adapter->dev, "ioctl, cmd=0x%02x, arg=0x%02lx\n",
180 case I2C_SLAVE_FORCE:
182 (((client->flags & I2C_M_TEN) == 0) && arg > 0x7f))
184 if ((cmd == I2C_SLAVE) && i2c_check_addr(client->adapter,arg))
190 client->flags |= I2C_M_TEN;
192 client->flags &= ~I2C_M_TEN;
196 client->flags |= I2C_CLIENT_PEC;
198 client->flags &= ~I2C_CLIENT_PEC;
201 funcs = i2c_get_functionality(client->adapter);
202 return (copy_to_user((unsigned long __user *)arg, &funcs,
203 sizeof(unsigned long)))?-EFAULT:0;
206 if (copy_from_user(&rdwr_arg,
207 (struct i2c_rdwr_ioctl_data __user *)arg,
211 /* Put an arbitrary limit on the number of messages that can
213 if (rdwr_arg.nmsgs > I2C_RDRW_IOCTL_MAX_MSGS)
216 rdwr_pa = (struct i2c_msg *)
217 kmalloc(rdwr_arg.nmsgs * sizeof(struct i2c_msg),
220 if (rdwr_pa == NULL) return -ENOMEM;
222 if (copy_from_user(rdwr_pa, rdwr_arg.msgs,
223 rdwr_arg.nmsgs * sizeof(struct i2c_msg))) {
228 data_ptrs = kmalloc(rdwr_arg.nmsgs * sizeof(u8 __user *), GFP_KERNEL);
229 if (data_ptrs == NULL) {
235 for( i=0; i<rdwr_arg.nmsgs; i++ ) {
236 /* Limit the size of the message to a sane amount */
237 if (rdwr_pa[i].len > 8192) {
241 data_ptrs[i] = (u8 __user *)rdwr_pa[i].buf;
242 rdwr_pa[i].buf = kmalloc(rdwr_pa[i].len, GFP_KERNEL);
243 if(rdwr_pa[i].buf == NULL) {
247 if(copy_from_user(rdwr_pa[i].buf,
250 ++i; /* Needs to be kfreed too */
257 for (j = 0; j < i; ++j)
258 kfree(rdwr_pa[j].buf);
264 res = i2c_transfer(client->adapter,
268 if( res>=0 && (rdwr_pa[i].flags & I2C_M_RD)) {
276 kfree(rdwr_pa[i].buf);
283 if (copy_from_user(&data_arg,
284 (struct i2c_smbus_ioctl_data __user *) arg,
285 sizeof(struct i2c_smbus_ioctl_data)))
287 if ((data_arg.size != I2C_SMBUS_BYTE) &&
288 (data_arg.size != I2C_SMBUS_QUICK) &&
289 (data_arg.size != I2C_SMBUS_BYTE_DATA) &&
290 (data_arg.size != I2C_SMBUS_WORD_DATA) &&
291 (data_arg.size != I2C_SMBUS_PROC_CALL) &&
292 (data_arg.size != I2C_SMBUS_BLOCK_DATA) &&
293 (data_arg.size != I2C_SMBUS_I2C_BLOCK_DATA) &&
294 (data_arg.size != I2C_SMBUS_BLOCK_PROC_CALL)) {
295 dev_dbg(&client->adapter->dev,
296 "size out of range (%x) in ioctl I2C_SMBUS.\n",
300 /* Note that I2C_SMBUS_READ and I2C_SMBUS_WRITE are 0 and 1,
301 so the check is valid if size==I2C_SMBUS_QUICK too. */
302 if ((data_arg.read_write != I2C_SMBUS_READ) &&
303 (data_arg.read_write != I2C_SMBUS_WRITE)) {
304 dev_dbg(&client->adapter->dev,
305 "read_write out of range (%x) in ioctl I2C_SMBUS.\n",
306 data_arg.read_write);
310 /* Note that command values are always valid! */
312 if ((data_arg.size == I2C_SMBUS_QUICK) ||
313 ((data_arg.size == I2C_SMBUS_BYTE) &&
314 (data_arg.read_write == I2C_SMBUS_WRITE)))
315 /* These are special: we do not use data */
316 return i2c_smbus_xfer(client->adapter, client->addr,
320 data_arg.size, NULL);
322 if (data_arg.data == NULL) {
323 dev_dbg(&client->adapter->dev,
324 "data is NULL pointer in ioctl I2C_SMBUS.\n");
328 if ((data_arg.size == I2C_SMBUS_BYTE_DATA) ||
329 (data_arg.size == I2C_SMBUS_BYTE))
330 datasize = sizeof(data_arg.data->byte);
331 else if ((data_arg.size == I2C_SMBUS_WORD_DATA) ||
332 (data_arg.size == I2C_SMBUS_PROC_CALL))
333 datasize = sizeof(data_arg.data->word);
334 else /* size == smbus block, i2c block, or block proc. call */
335 datasize = sizeof(data_arg.data->block);
337 if ((data_arg.size == I2C_SMBUS_PROC_CALL) ||
338 (data_arg.size == I2C_SMBUS_BLOCK_PROC_CALL) ||
339 (data_arg.read_write == I2C_SMBUS_WRITE)) {
340 if (copy_from_user(&temp, data_arg.data, datasize))
343 res = i2c_smbus_xfer(client->adapter,client->addr,client->flags,
345 data_arg.command,data_arg.size,&temp);
346 if (! res && ((data_arg.size == I2C_SMBUS_PROC_CALL) ||
347 (data_arg.size == I2C_SMBUS_BLOCK_PROC_CALL) ||
348 (data_arg.read_write == I2C_SMBUS_READ))) {
349 if (copy_to_user(data_arg.data, &temp, datasize))
355 return i2c_control(client,cmd,arg);
360 static int i2cdev_open(struct inode *inode, struct file *file)
362 unsigned int minor = iminor(inode);
363 struct i2c_client *client;
364 struct i2c_adapter *adap;
365 struct i2c_dev *i2c_dev;
367 i2c_dev = i2c_dev_get_by_minor(minor);
371 adap = i2c_get_adapter(i2c_dev->adap->nr);
375 client = kmalloc(sizeof(*client), GFP_KERNEL);
377 i2c_put_adapter(adap);
380 memcpy(client, &i2cdev_client_template, sizeof(*client));
382 /* registered with adapter, passed as client to user */
383 client->adapter = adap;
384 file->private_data = client;
389 static int i2cdev_release(struct inode *inode, struct file *file)
391 struct i2c_client *client = file->private_data;
393 i2c_put_adapter(client->adapter);
395 file->private_data = NULL;
400 static struct file_operations i2cdev_fops = {
401 .owner = THIS_MODULE,
404 .write = i2cdev_write,
405 .ioctl = i2cdev_ioctl,
407 .release = i2cdev_release,
410 static void release_i2c_dev(struct class_device *dev)
412 struct i2c_dev *i2c_dev = to_i2c_dev(dev);
413 complete(&i2c_dev->released);
416 static struct class i2c_dev_class = {
418 .release = &release_i2c_dev,
421 static int i2cdev_attach_adapter(struct i2c_adapter *adap)
423 struct i2c_dev *i2c_dev;
426 i2c_dev = get_free_i2c_dev(adap);
428 return PTR_ERR(i2c_dev);
430 pr_debug("i2c-dev: adapter [%s] registered as minor %d\n",
431 adap->name, i2c_dev->minor);
433 /* register this i2c device with the driver core */
434 i2c_dev->adap = adap;
435 if (adap->dev.parent == &platform_bus)
436 i2c_dev->class_dev.dev = &adap->dev;
438 i2c_dev->class_dev.dev = adap->dev.parent;
439 i2c_dev->class_dev.class = &i2c_dev_class;
440 i2c_dev->class_dev.devt = MKDEV(I2C_MAJOR, i2c_dev->minor);
441 snprintf(i2c_dev->class_dev.class_id, BUS_ID_SIZE, "i2c-%d", i2c_dev->minor);
442 retval = class_device_register(&i2c_dev->class_dev);
445 class_device_create_file(&i2c_dev->class_dev, &class_device_attr_name);
448 return_i2c_dev(i2c_dev);
453 static int i2cdev_detach_adapter(struct i2c_adapter *adap)
455 struct i2c_dev *i2c_dev;
457 i2c_dev = i2c_dev_get_by_adapter(adap);
461 init_completion(&i2c_dev->released);
462 return_i2c_dev(i2c_dev);
463 class_device_unregister(&i2c_dev->class_dev);
464 wait_for_completion(&i2c_dev->released);
467 pr_debug("i2c-dev: adapter [%s] unregistered\n", adap->name);
471 static int i2cdev_detach_client(struct i2c_client *client)
476 static int i2cdev_command(struct i2c_client *client, unsigned int cmd,
482 static struct i2c_driver i2cdev_driver = {
483 .owner = THIS_MODULE,
484 .name = "dev_driver",
485 .id = I2C_DRIVERID_I2CDEV,
486 .flags = I2C_DF_NOTIFY,
487 .attach_adapter = i2cdev_attach_adapter,
488 .detach_adapter = i2cdev_detach_adapter,
489 .detach_client = i2cdev_detach_client,
490 .command = i2cdev_command,
493 static struct i2c_client i2cdev_client_template = {
494 .name = "I2C /dev entry",
496 .driver = &i2cdev_driver,
499 static int __init i2c_dev_init(void)
503 printk(KERN_INFO "i2c /dev entries driver\n");
505 res = register_chrdev(I2C_MAJOR, "i2c", &i2cdev_fops);
509 res = class_register(&i2c_dev_class);
511 goto out_unreg_chrdev;
513 res = i2c_add_driver(&i2cdev_driver);
515 goto out_unreg_class;
520 class_unregister(&i2c_dev_class);
522 unregister_chrdev(I2C_MAJOR, "i2c");
524 printk(KERN_ERR "%s: Driver Initialisation failed\n", __FILE__);
528 static void __exit i2c_dev_exit(void)
530 i2c_del_driver(&i2cdev_driver);
531 class_unregister(&i2c_dev_class);
532 unregister_chrdev(I2C_MAJOR,"i2c");
535 MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl> and "
536 "Simon G. Vogl <simon@tk.uni-linz.ac.at>");
537 MODULE_DESCRIPTION("I2C /dev entries driver");
538 MODULE_LICENSE("GPL");
540 module_init(i2c_dev_init);
541 module_exit(i2c_dev_exit);