WebSVN - shark - Blame - Rev 458 - /shark/trunk/drivers/i2c/i2c-dev.c

Rev	Author	Line No.	Line
420	giacomo	1	/*
		2	i2c-dev.c - i2c-bus driver, char device interface
		3
		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>
		7
		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.
		12
		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.
		17
		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.
		21	*/
		22
		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 */
		26
		27	/* The I2C_RDWR ioctl code is written by Kolja Waschk <waschk@telos.de> */
		28
		29	/* The devfs code is contributed by Philipp Matthias Hahn
		30	<pmhahn@titan.lahn.de> */
		31
		32	/* If you want debugging uncomment: */
		33	/* #define DEBUG 1 */
		34
458	giacomo	35	#include <linuxcomp.h>
		36
420	giacomo	37	#include <linux/kernel.h>
		38	#include <linux/module.h>
		39	#include <linux/fs.h>
		40	#include <linux/slab.h>
		41	#include <linux/smp_lock.h>
		42	#include <linux/devfs_fs_kernel.h>
		43	#include <linux/init.h>
		44	#include <linux/i2c.h>
		45	#include <linux/i2c-dev.h>
		46	#include <asm/uaccess.h>
		47
		48	static struct i2c_client i2cdev_client_template;
		49
		50	struct i2c_dev {
		51	int minor;
		52	struct i2c_adapter *adap;
		53	struct class_device class_dev;
		54	struct completion released; /* FIXME, we need a class_device_unregister() */
		55	};
		56	#define to_i2c_dev(d) container_of(d, struct i2c_dev, class_dev)
		57
		58	#define I2C_MINORS 256
		59	static struct i2c_dev *i2c_dev_array[I2C_MINORS];
		60	static spinlock_t i2c_dev_array_lock = SPIN_LOCK_UNLOCKED;
		61
		62	struct i2c_dev *i2c_dev_get_by_minor(unsigned index)
		63	{
		64	struct i2c_dev *i2c_dev;
		65
		66	spin_lock(&i2c_dev_array_lock);
		67	i2c_dev = i2c_dev_array[index];
		68	spin_unlock(&i2c_dev_array_lock);
		69	return i2c_dev;
		70	}
		71
		72	struct i2c_dev i2c_dev_get_by_adapter(struct i2c_adapter adap)
		73	{
		74	struct i2c_dev *i2c_dev = NULL;
		75	int i;
		76
		77	spin_lock(&i2c_dev_array_lock);
		78	for (i = 0; i < I2C_MINORS; ++i) {
		79	if ((i2c_dev_array[i]) &&
		80	(i2c_dev_array[i]->adap == adap)) {
		81	i2c_dev = i2c_dev_array[i];
		82	break;
		83	}
		84	}
		85	spin_unlock(&i2c_dev_array_lock);
		86	return i2c_dev;
		87	}
		88
		89	static struct i2c_dev *get_free_i2c_dev(void)
		90	{
		91	struct i2c_dev *i2c_dev;
		92	unsigned int i;
		93
		94	i2c_dev = kmalloc(sizeof(*i2c_dev), GFP_KERNEL);
		95	if (!i2c_dev)
		96	return ERR_PTR(-ENOMEM);
		97	memset(i2c_dev, 0x00, sizeof(*i2c_dev));
		98
		99	spin_lock(&i2c_dev_array_lock);
		100	for (i = 0; i < I2C_MINORS; ++i) {
		101	if (i2c_dev_array[i])
		102	continue;
		103	i2c_dev->minor = i;
		104	i2c_dev_array[i] = i2c_dev;
		105	spin_unlock(&i2c_dev_array_lock);
		106	return i2c_dev;
		107	}
		108	spin_unlock(&i2c_dev_array_lock);
		109	kfree(i2c_dev);
		110	return ERR_PTR(-ENODEV);
		111	}
		112
		113	static void return_i2c_dev(struct i2c_dev *i2c_dev)
		114	{
		115	spin_lock(&i2c_dev_array_lock);
		116	i2c_dev_array[i2c_dev->minor] = NULL;
		117	spin_unlock(&i2c_dev_array_lock);
		118	}
		119
		120	static ssize_t show_dev(struct class_device class_dev, char buf)
		121	{
		122	struct i2c_dev *i2c_dev = to_i2c_dev(class_dev);
		123	return print_dev_t(buf, MKDEV(I2C_MAJOR, i2c_dev->minor));
		124	}
		125	static CLASS_DEVICE_ATTR(dev, S_IRUGO, show_dev, NULL);
		126
		127	static ssize_t i2cdev_read (struct file file, char __user buf, size_t count,
		128	loff_t *offset)
		129	{
		130	char *tmp;
		131	int ret;
		132
		133	struct i2c_client client = (struct i2c_client )file->private_data;
		134
		135	if (count > 8192)
		136	count = 8192;
		137
		138	tmp = kmalloc(count,GFP_KERNEL);
		139	if (tmp==NULL)
		140	return -ENOMEM;
		141
		142	pr_debug("i2c-dev.o: i2c-%d reading %d bytes.\n",
		143	iminor(file->f_dentry->d_inode), count);
		144
		145	ret = i2c_master_recv(client,tmp,count);
		146	if (ret >= 0)
		147	ret = copy_to_user(buf,tmp,count)?-EFAULT:ret;
		148	kfree(tmp);
		149	return ret;
		150	}
		151
		152	static ssize_t i2cdev_write (struct file file, const char __user buf, size_t count,
		153	loff_t *offset)
		154	{
		155	int ret;
		156	char *tmp;
		157	struct i2c_client client = (struct i2c_client )file->private_data;
		158
		159	if (count > 8192)
		160	count = 8192;
		161
		162	tmp = kmalloc(count,GFP_KERNEL);
		163	if (tmp==NULL)
		164	return -ENOMEM;
		165	if (copy_from_user(tmp,buf,count)) {
		166	kfree(tmp);
		167	return -EFAULT;
		168	}
		169
		170	pr_debug("i2c-dev.o: i2c-%d writing %d bytes.\n",
		171	iminor(file->f_dentry->d_inode), count);
		172
		173	ret = i2c_master_send(client,tmp,count);
		174	kfree(tmp);
		175	return ret;
		176	}
		177
		178	int i2cdev_ioctl (struct inode inode, struct file file, unsigned int cmd,
		179	unsigned long arg)
		180	{
		181	struct i2c_client client = (struct i2c_client )file->private_data;
		182	struct i2c_rdwr_ioctl_data rdwr_arg;
		183	struct i2c_smbus_ioctl_data data_arg;
		184	union i2c_smbus_data temp;
		185	struct i2c_msg *rdwr_pa;
		186	u8 **data_ptrs;
		187	int i,datasize,res;
		188	unsigned long funcs;
		189
		190	dev_dbg(&client->dev, "i2c-%d ioctl, cmd: 0x%x, arg: %lx.\n",
		191	iminor(inode),cmd, arg);
		192
		193	switch ( cmd ) {
		194	case I2C_SLAVE:
		195	case I2C_SLAVE_FORCE:
		196	if ((arg > 0x3ff) \|\|
		197	(((client->flags & I2C_M_TEN) == 0) && arg > 0x7f))
		198	return -EINVAL;
		199	if ((cmd == I2C_SLAVE) && i2c_check_addr(client->adapter,arg))
		200	return -EBUSY;
		201	client->addr = arg;
		202	return 0;
		203	case I2C_TENBIT:
		204	if (arg)
		205	client->flags \|= I2C_M_TEN;
		206	else
		207	client->flags &= ~I2C_M_TEN;
		208	return 0;
		209	case I2C_PEC:
		210	if (arg)
		211	client->flags \|= I2C_CLIENT_PEC;
		212	else
		213	client->flags &= ~I2C_CLIENT_PEC;
		214	return 0;
		215	case I2C_FUNCS:
		216	funcs = i2c_get_functionality(client->adapter);
		217	return (copy_to_user((unsigned long __user *)arg, &funcs,
		218	sizeof(unsigned long)))?-EFAULT:0;
		219
		220	case I2C_RDWR:
		221	if (copy_from_user(&rdwr_arg,
		222	(struct i2c_rdwr_ioctl_data __user *)arg,
		223	sizeof(rdwr_arg)))
		224	return -EFAULT;
		225
		226	/* Put an arbritrary limit on the number of messages that can
		227	* be sent at once */
		228	if (rdwr_arg.nmsgs > 42)
		229	return -EINVAL;
		230
		231	rdwr_pa = (struct i2c_msg *)
		232	kmalloc(rdwr_arg.nmsgs * sizeof(struct i2c_msg),
		233	GFP_KERNEL);
		234
		235	if (rdwr_pa == NULL) return -ENOMEM;
		236
		237	if (copy_from_user(rdwr_pa, rdwr_arg.msgs,
		238	rdwr_arg.nmsgs * sizeof(struct i2c_msg))) {
		239	kfree(rdwr_pa);
		240	return -EFAULT;
		241	}
		242
		243	data_ptrs = (u8 *) kmalloc(rdwr_arg.nmsgs sizeof(u8 *),
		244	GFP_KERNEL);
		245	if (data_ptrs == NULL) {
		246	kfree(rdwr_pa);
		247	return -ENOMEM;
		248	}
		249
		250	res = 0;
		251	for( i=0; i<rdwr_arg.nmsgs; i++ ) {
		252	/* Limit the size of the message to a sane amount */
		253	if (rdwr_pa[i].len > 8192) {
		254	res = -EINVAL;
		255	break;
		256	}
		257	data_ptrs[i] = rdwr_pa[i].buf;
		258	rdwr_pa[i].buf = kmalloc(rdwr_pa[i].len, GFP_KERNEL);
		259	if(rdwr_pa[i].buf == NULL) {
		260	res = -ENOMEM;
		261	break;
		262	}
		263	if(copy_from_user(rdwr_pa[i].buf,
		264	data_ptrs[i],
		265	rdwr_pa[i].len)) {
		266	++i; /* Needs to be kfreed too */
		267	res = -EFAULT;
		268	break;
		269	}
		270	}
		271	if (res < 0) {
		272	int j;
		273	for (j = 0; j < i; ++j)
		274	kfree(rdwr_pa[j].buf);
		275	kfree(data_ptrs);
		276	kfree(rdwr_pa);
		277	return res;
		278	}
		279
		280	res = i2c_transfer(client->adapter,
		281	rdwr_pa,
		282	rdwr_arg.nmsgs);
		283	while(i-- > 0) {
		284	if( res>=0 && (rdwr_pa[i].flags & I2C_M_RD)) {
		285	if(copy_to_user(
		286	data_ptrs[i],
		287	rdwr_pa[i].buf,
		288	rdwr_pa[i].len)) {
		289	res = -EFAULT;
		290	}
		291	}
		292	kfree(rdwr_pa[i].buf);
		293	}
		294	kfree(data_ptrs);
		295	kfree(rdwr_pa);
		296	return res;
		297
		298	case I2C_SMBUS:
		299	if (copy_from_user(&data_arg,
		300	(struct i2c_smbus_ioctl_data __user *) arg,
		301	sizeof(struct i2c_smbus_ioctl_data)))
		302	return -EFAULT;
		303	if ((data_arg.size != I2C_SMBUS_BYTE) &&
		304	(data_arg.size != I2C_SMBUS_QUICK) &&
		305	(data_arg.size != I2C_SMBUS_BYTE_DATA) &&
		306	(data_arg.size != I2C_SMBUS_WORD_DATA) &&
		307	(data_arg.size != I2C_SMBUS_PROC_CALL) &&
		308	(data_arg.size != I2C_SMBUS_BLOCK_DATA) &&
		309	(data_arg.size != I2C_SMBUS_I2C_BLOCK_DATA) &&
		310	(data_arg.size != I2C_SMBUS_BLOCK_PROC_CALL)) {
		311	dev_dbg(&client->dev,
		312	"size out of range (%x) in ioctl I2C_SMBUS.\n",
		313	data_arg.size);
		314	return -EINVAL;
		315	}
		316	/* Note that I2C_SMBUS_READ and I2C_SMBUS_WRITE are 0 and 1,
		317	so the check is valid if size==I2C_SMBUS_QUICK too. */
		318	if ((data_arg.read_write != I2C_SMBUS_READ) &&
		319	(data_arg.read_write != I2C_SMBUS_WRITE)) {
		320	dev_dbg(&client->dev,
		321	"read_write out of range (%x) in ioctl I2C_SMBUS.\n",
		322	data_arg.read_write);
		323	return -EINVAL;
		324	}
		325
		326	/* Note that command values are always valid! */
		327
		328	if ((data_arg.size == I2C_SMBUS_QUICK) \|\|
		329	((data_arg.size == I2C_SMBUS_BYTE) &&
		330	(data_arg.read_write == I2C_SMBUS_WRITE)))
		331	/* These are special: we do not use data */
		332	return i2c_smbus_xfer(client->adapter, client->addr,
		333	client->flags,
		334	data_arg.read_write,
		335	data_arg.command,
		336	data_arg.size, NULL);
		337
		338	if (data_arg.data == NULL) {
		339	dev_dbg(&client->dev,
		340	"data is NULL pointer in ioctl I2C_SMBUS.\n");
		341	return -EINVAL;
		342	}
		343
		344	if ((data_arg.size == I2C_SMBUS_BYTE_DATA) \|\|
		345	(data_arg.size == I2C_SMBUS_BYTE))
		346	datasize = sizeof(data_arg.data->byte);
		347	else if ((data_arg.size == I2C_SMBUS_WORD_DATA) \|\|
		348	(data_arg.size == I2C_SMBUS_PROC_CALL))
		349	datasize = sizeof(data_arg.data->word);
		350	else /* size == smbus block, i2c block, or block proc. call */
		351	datasize = sizeof(data_arg.data->block);
		352
		353	if ((data_arg.size == I2C_SMBUS_PROC_CALL) \|\|
		354	(data_arg.size == I2C_SMBUS_BLOCK_PROC_CALL) \|\|
		355	(data_arg.read_write == I2C_SMBUS_WRITE)) {
		356	if (copy_from_user(&temp, data_arg.data, datasize))
		357	return -EFAULT;
		358	}
		359	res = i2c_smbus_xfer(client->adapter,client->addr,client->flags,
		360	data_arg.read_write,
		361	data_arg.command,data_arg.size,&temp);
		362	if (! res && ((data_arg.size == I2C_SMBUS_PROC_CALL) \|\|
		363	(data_arg.size == I2C_SMBUS_BLOCK_PROC_CALL) \|\|
		364	(data_arg.read_write == I2C_SMBUS_READ))) {
		365	if (copy_to_user(data_arg.data, &temp, datasize))
		366	return -EFAULT;
		367	}
		368	return res;
		369
		370	default:
		371	return i2c_control(client,cmd,arg);
		372	}
		373	return 0;
		374	}
		375
		376	static int i2cdev_open(struct inode inode, struct file file)
		377	{
		378	unsigned int minor = iminor(inode);
		379	struct i2c_client *client;
		380	struct i2c_adapter *adap;
		381	struct i2c_dev *i2c_dev;
		382
		383	i2c_dev = i2c_dev_get_by_minor(minor);
		384	if (!i2c_dev)
		385	return -ENODEV;
		386
		387	adap = i2c_get_adapter(i2c_dev->adap->nr);
		388	if (!adap)
		389	return -ENODEV;
		390
		391	client = kmalloc(sizeof(*client), GFP_KERNEL);
		392	if (!client) {
		393	i2c_put_adapter(adap);
		394	return -ENOMEM;
		395	}
		396	memcpy(client, &i2cdev_client_template, sizeof(*client));
		397
		398	/* registered with adapter, passed as client to user */
		399	client->adapter = adap;
		400	file->private_data = client;
		401
		402	return 0;
		403	}
		404
		405	static int i2cdev_release(struct inode inode, struct file file)
		406	{
		407	struct i2c_client *client = file->private_data;
		408
		409	i2c_put_adapter(client->adapter);
		410	kfree(client);
		411	file->private_data = NULL;
		412
		413	return 0;
		414	}
		415
		416	static struct file_operations i2cdev_fops = {
		417	.owner = THIS_MODULE,
		418	.llseek = no_llseek,
		419	.read = i2cdev_read,
		420	.write = i2cdev_write,
		421	.ioctl = i2cdev_ioctl,
		422	.open = i2cdev_open,
		423	.release = i2cdev_release,
		424	};
		425
		426	static void release_i2c_dev(struct class_device *dev)
		427	{
		428	struct i2c_dev *i2c_dev = to_i2c_dev(dev);
		429	complete(&i2c_dev->released);
		430	}
		431
		432	static struct class i2c_dev_class = {
		433	.name = "i2c-dev",
		434	.release = &release_i2c_dev,
		435	};
		436
		437	static int i2cdev_attach_adapter(struct i2c_adapter *adap)
		438	{
		439	struct i2c_dev *i2c_dev;
		440	int retval;
		441
		442	i2c_dev = get_free_i2c_dev();
		443	if (IS_ERR(i2c_dev))
		444	return PTR_ERR(i2c_dev);
		445
		446	devfs_mk_cdev(MKDEV(I2C_MAJOR, i2c_dev->minor),
		447	S_IFCHR\|S_IRUSR\|S_IWUSR, "i2c/%d", i2c_dev->minor);
		448	dev_dbg(&adap->dev, "Registered as minor %d\n", i2c_dev->minor);
		449
		450	/* register this i2c device with the driver core */
		451	i2c_dev->adap = adap;
		452	if (adap->dev.parent == &legacy_bus)
		453	i2c_dev->class_dev.dev = &adap->dev;
		454	else
		455	i2c_dev->class_dev.dev = adap->dev.parent;
		456	i2c_dev->class_dev.class = &i2c_dev_class;
458	giacomo	457	snprintf26(i2c_dev->class_dev.class_id, BUS_ID_SIZE, "i2c-%d", i2c_dev->minor);
420	giacomo	458	retval = class_device_register(&i2c_dev->class_dev);
		459	if (retval)
		460	goto error;
		461	class_device_create_file(&i2c_dev->class_dev, &class_device_attr_dev);
		462	return 0;
		463	error:
		464	return_i2c_dev(i2c_dev);
		465	kfree(i2c_dev);
		466	return retval;
		467	}
		468
		469	static int i2cdev_detach_adapter(struct i2c_adapter *adap)
		470	{
		471	struct i2c_dev *i2c_dev;
		472
		473	i2c_dev = i2c_dev_get_by_adapter(adap);
		474	if (!i2c_dev)
		475	return -ENODEV;
		476
		477	init_completion(&i2c_dev->released);
		478	devfs_remove("i2c/%d", i2c_dev->minor);
		479	return_i2c_dev(i2c_dev);
		480	class_device_unregister(&i2c_dev->class_dev);
		481	wait_for_completion(&i2c_dev->released);
		482	kfree(i2c_dev);
		483
		484	dev_dbg(&adap->dev, "Adapter unregistered\n");
		485	return 0;
		486	}
		487
		488	static int i2cdev_detach_client(struct i2c_client *client)
		489	{
		490	return 0;
		491	}
		492
		493	static int i2cdev_command(struct i2c_client *client, unsigned int cmd,
		494	void *arg)
		495	{
		496	return -1;
		497	}
		498
		499	static struct i2c_driver i2cdev_driver = {
		500	.owner = THIS_MODULE,
		501	.name = "dev_driver",
		502	.id = I2C_DRIVERID_I2CDEV,
		503	.flags = I2C_DF_NOTIFY,
		504	.attach_adapter = i2cdev_attach_adapter,
		505	.detach_adapter = i2cdev_detach_adapter,
		506	.detach_client = i2cdev_detach_client,
		507	.command = i2cdev_command,
		508	};
		509
		510	static struct i2c_client i2cdev_client_template = {
		511	.name = "I2C /dev entry",
		512	.id = 1,
		513	.addr = -1,
		514	.driver = &i2cdev_driver,
		515	};
		516
458	giacomo	517	int __init i2c_dev_init(void)
420	giacomo	518	{
		519	int res;
		520
		521	printk(KERN_INFO "i2c /dev entries driver\n");
		522
		523	if (register_chrdev(I2C_MAJOR,"i2c",&i2cdev_fops)) {
		524	printk(KERN_ERR "i2c-dev.o: unable to get major %d for i2c bus\n",
		525	I2C_MAJOR);
		526	return -EIO;
		527	}
		528	devfs_mk_dir("i2c");
		529	class_register(&i2c_dev_class);
		530	if ((res = i2c_add_driver(&i2cdev_driver))) {
		531	printk(KERN_ERR "i2c-dev.o: Driver registration failed, module not inserted.\n");
		532	devfs_remove("i2c");
		533	unregister_chrdev(I2C_MAJOR,"i2c");
		534	return res;
		535	}
		536	return 0;
		537	}
		538
		539	static void __exit i2c_dev_exit(void)
		540	{
		541	i2c_del_driver(&i2cdev_driver);
		542	class_unregister(&i2c_dev_class);
		543	devfs_remove("i2c");
		544	unregister_chrdev(I2C_MAJOR,"i2c");
		545	}
		546
		547	MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl> and "
		548	"Simon G. Vogl <simon@tk.uni-linz.ac.at>");
		549	MODULE_DESCRIPTION("I2C /dev entries driver");
		550	MODULE_LICENSE("GPL");
		551
		552	module_init(i2c_dev_init);
		553	module_exit(i2c_dev_exit);

Subversion Repositories shark

(root)/shark/trunk/drivers/i2c/i2c-dev.c - Rev 458