/* i2c-dev.c - i2c-bus driver, char device interface Copyright (C) 1995-97 Simon G. Vogl Copyright (C) 1998-99 Frodo Looijaard Copyright (C) 2003 Greg Kroah-Hartman This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ /* Note that this is a complete rewrite of Simon Vogl's i2c-dev module. But I have used so much of his original code and ideas that it seems only fair to recognize him as co-author -- Frodo */ /* The I2C_RDWR ioctl code is written by Kolja Waschk */ #include #include #include #include #include #include #include #include #include #include static struct i2c_driver i2cdev_driver; struct i2c_dev { struct list_head list; struct i2c_adapter *adap; struct class_device *class_dev; }; #define I2C_MINORS 256 static LIST_HEAD(i2c_dev_list); static DEFINE_SPINLOCK(i2c_dev_list_lock); static struct i2c_dev *i2c_dev_get_by_minor(unsigned index) { struct i2c_dev *i2c_dev; spin_lock(&i2c_dev_list_lock); list_for_each_entry(i2c_dev, &i2c_dev_list, list) { if (i2c_dev->adap->nr == index) goto found; } i2c_dev = NULL; found: spin_unlock(&i2c_dev_list_lock); return i2c_dev; } static struct i2c_dev *get_free_i2c_dev(struct i2c_adapter *adap) { struct i2c_dev *i2c_dev; if (adap->nr >= I2C_MINORS) { printk(KERN_ERR "i2c-dev: Out of device minors (%d)\n", adap->nr); return ERR_PTR(-ENODEV); } i2c_dev = kzalloc(sizeof(*i2c_dev), GFP_KERNEL); if (!i2c_dev) return ERR_PTR(-ENOMEM); i2c_dev->adap = adap; spin_lock(&i2c_dev_list_lock); list_add_tail(&i2c_dev->list, &i2c_dev_list); spin_unlock(&i2c_dev_list_lock); return i2c_dev; } static void return_i2c_dev(struct i2c_dev *i2c_dev) { spin_lock(&i2c_dev_list_lock); list_del(&i2c_dev->list); spin_unlock(&i2c_dev_list_lock); } static ssize_t show_adapter_name(struct class_device *class_dev, char *buf) { struct i2c_dev *i2c_dev = i2c_dev_get_by_minor(MINOR(class_dev->devt)); if (!i2c_dev) return -ENODEV; return sprintf(buf, "%s\n", i2c_dev->adap->name); } static CLASS_DEVICE_ATTR(name, S_IRUGO, show_adapter_name, NULL); static ssize_t i2cdev_read (struct file *file, char __user *buf, size_t count, loff_t *offset) { char *tmp; int ret; struct i2c_client *client = (struct i2c_client *)file->private_data; if (count > 8192) count = 8192; tmp = kmalloc(count,GFP_KERNEL); if (tmp==NULL) return -ENOMEM; pr_debug("i2c-dev: i2c-%d reading %zd bytes.\n", iminor(file->f_dentry->d_inode), count); ret = i2c_master_recv(client,tmp,count); if (ret >= 0) ret = copy_to_user(buf,tmp,count)?-EFAULT:ret; kfree(tmp); return ret; } static ssize_t i2cdev_write (struct file *file, const char __user *buf, size_t count, loff_t *offset) { int ret; char *tmp; struct i2c_client *client = (struct i2c_client *)file->private_data; if (count > 8192) count = 8192; tmp = kmalloc(count,GFP_KERNEL); if (tmp==NULL) return -ENOMEM; if (copy_from_user(tmp,buf,count)) { kfree(tmp); return -EFAULT; } pr_debug("i2c-dev: i2c-%d writing %zd bytes.\n", iminor(file->f_dentry->d_inode), count); ret = i2c_master_send(client,tmp,count); kfree(tmp); return ret; } static int i2cdev_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg) { struct i2c_client *client = (struct i2c_client *)file->private_data; struct i2c_rdwr_ioctl_data rdwr_arg; struct i2c_smbus_ioctl_data data_arg; union i2c_smbus_data temp; struct i2c_msg *rdwr_pa; u8 __user **data_ptrs; int i,datasize,res; unsigned long funcs; dev_dbg(&client->adapter->dev, "ioctl, cmd=0x%02x, arg=0x%02lx\n", cmd, arg); switch ( cmd ) { case I2C_SLAVE: case I2C_SLAVE_FORCE: if ((arg > 0x3ff) || (((client->flags & I2C_M_TEN) == 0) && arg > 0x7f)) return -EINVAL; if ((cmd == I2C_SLAVE) && i2c_check_addr(client->adapter,arg)) return -EBUSY; client->addr = arg; return 0; case I2C_TENBIT: if (arg) client->flags |= I2C_M_TEN; else client->flags &= ~I2C_M_TEN; return 0; case I2C_PEC: if (arg) client->flags |= I2C_CLIENT_PEC; else client->flags &= ~I2C_CLIENT_PEC; return 0; case I2C_FUNCS: funcs = i2c_get_functionality(client->adapter); return (copy_to_user((unsigned long __user *)arg, &funcs, sizeof(unsigned long)))?-EFAULT:0; case I2C_RDWR: if (copy_from_user(&rdwr_arg, (struct i2c_rdwr_ioctl_data __user *)arg, sizeof(rdwr_arg))) return -EFAULT; /* Put an arbitrary limit on the number of messages that can * be sent at once */ if (rdwr_arg.nmsgs > I2C_RDRW_IOCTL_MAX_MSGS) return -EINVAL; rdwr_pa = (struct i2c_msg *) kmalloc(rdwr_arg.nmsgs * sizeof(struct i2c_msg), GFP_KERNEL); if (rdwr_pa == NULL) return -ENOMEM; if (copy_from_user(rdwr_pa, rdwr_arg.msgs, rdwr_arg.nmsgs * sizeof(struct i2c_msg))) { kfree(rdwr_pa); return -EFAULT; } data_ptrs = kmalloc(rdwr_arg.nmsgs * sizeof(u8 __user *), GFP_KERNEL); if (data_ptrs == NULL) { kfree(rdwr_pa); return -ENOMEM; } res = 0; for( i=0; i 8192) { res = -EINVAL; break; } data_ptrs[i] = (u8 __user *)rdwr_pa[i].buf; rdwr_pa[i].buf = kmalloc(rdwr_pa[i].len, GFP_KERNEL); if(rdwr_pa[i].buf == NULL) { res = -ENOMEM; break; } if(copy_from_user(rdwr_pa[i].buf, data_ptrs[i], rdwr_pa[i].len)) { ++i; /* Needs to be kfreed too */ res = -EFAULT; break; } } if (res < 0) { int j; for (j = 0; j < i; ++j) kfree(rdwr_pa[j].buf); kfree(data_ptrs); kfree(rdwr_pa); return res; } res = i2c_transfer(client->adapter, rdwr_pa, rdwr_arg.nmsgs); while(i-- > 0) { if( res>=0 && (rdwr_pa[i].flags & I2C_M_RD)) { if(copy_to_user( data_ptrs[i], rdwr_pa[i].buf, rdwr_pa[i].len)) { res = -EFAULT; } } kfree(rdwr_pa[i].buf); } kfree(data_ptrs); kfree(rdwr_pa); return res; case I2C_SMBUS: if (copy_from_user(&data_arg, (struct i2c_smbus_ioctl_data __user *) arg, sizeof(struct i2c_smbus_ioctl_data))) return -EFAULT; if ((data_arg.size != I2C_SMBUS_BYTE) && (data_arg.size != I2C_SMBUS_QUICK) && (data_arg.size != I2C_SMBUS_BYTE_DATA) && (data_arg.size != I2C_SMBUS_WORD_DATA) && (data_arg.size != I2C_SMBUS_PROC_CALL) && (data_arg.size != I2C_SMBUS_BLOCK_DATA) && (data_arg.size != I2C_SMBUS_I2C_BLOCK_DATA) && (data_arg.size != I2C_SMBUS_BLOCK_PROC_CALL)) { dev_dbg(&client->adapter->dev, "size out of range (%x) in ioctl I2C_SMBUS.\n", data_arg.size); return -EINVAL; } /* Note that I2C_SMBUS_READ and I2C_SMBUS_WRITE are 0 and 1, so the check is valid if size==I2C_SMBUS_QUICK too. */ if ((data_arg.read_write != I2C_SMBUS_READ) && (data_arg.read_write != I2C_SMBUS_WRITE)) { dev_dbg(&client->adapter->dev, "read_write out of range (%x) in ioctl I2C_SMBUS.\n", data_arg.read_write); return -EINVAL; } /* Note that command values are always valid! */ if ((data_arg.size == I2C_SMBUS_QUICK) || ((data_arg.size == I2C_SMBUS_BYTE) && (data_arg.read_write == I2C_SMBUS_WRITE))) /* These are special: we do not use data */ return i2c_smbus_xfer(client->adapter, client->addr, client->flags, data_arg.read_write, data_arg.command, data_arg.size, NULL); if (data_arg.data == NULL) { dev_dbg(&client->adapter->dev, "data is NULL pointer in ioctl I2C_SMBUS.\n"); return -EINVAL; } if ((data_arg.size == I2C_SMBUS_BYTE_DATA) || (data_arg.size == I2C_SMBUS_BYTE)) datasize = sizeof(data_arg.data->byte); else if ((data_arg.size == I2C_SMBUS_WORD_DATA) || (data_arg.size == I2C_SMBUS_PROC_CALL)) datasize = sizeof(data_arg.data->word); else /* size == smbus block, i2c block, or block proc. call */ datasize = sizeof(data_arg.data->block); if ((data_arg.size == I2C_SMBUS_PROC_CALL) || (data_arg.size == I2C_SMBUS_BLOCK_PROC_CALL) || (data_arg.read_write == I2C_SMBUS_WRITE)) { if (copy_from_user(&temp, data_arg.data, datasize)) return -EFAULT; } res = i2c_smbus_xfer(client->adapter,client->addr,client->flags, data_arg.read_write, data_arg.command,data_arg.size,&temp); if (! res && ((data_arg.size == I2C_SMBUS_PROC_CALL) || (data_arg.size == I2C_SMBUS_BLOCK_PROC_CALL) || (data_arg.read_write == I2C_SMBUS_READ))) { if (copy_to_user(data_arg.data, &temp, datasize)) return -EFAULT; } return res; default: return i2c_control(client,cmd,arg); } return 0; } static int i2cdev_open(struct inode *inode, struct file *file) { unsigned int minor = iminor(inode); struct i2c_client *client; struct i2c_adapter *adap; struct i2c_dev *i2c_dev; i2c_dev = i2c_dev_get_by_minor(minor); if (!i2c_dev) return -ENODEV; adap = i2c_get_adapter(i2c_dev->adap->nr); if (!adap) return -ENODEV; client = kzalloc(sizeof(*client), GFP_KERNEL); if (!client) { i2c_put_adapter(adap); return -ENOMEM; } snprintf(client->name, I2C_NAME_SIZE, "i2c-dev %d", adap->nr); client->driver = &i2cdev_driver; /* registered with adapter, passed as client to user */ client->adapter = adap; file->private_data = client; return 0; } static int i2cdev_release(struct inode *inode, struct file *file) { struct i2c_client *client = file->private_data; i2c_put_adapter(client->adapter); kfree(client); file->private_data = NULL; return 0; } static struct file_operations i2cdev_fops = { .owner = THIS_MODULE, .llseek = no_llseek, .read = i2cdev_read, .write = i2cdev_write, .ioctl = i2cdev_ioctl, .open = i2cdev_open, .release = i2cdev_release, }; static struct class *i2c_dev_class; static int i2cdev_attach_adapter(struct i2c_adapter *adap) { struct i2c_dev *i2c_dev; i2c_dev = get_free_i2c_dev(adap); if (IS_ERR(i2c_dev)) return PTR_ERR(i2c_dev); pr_debug("i2c-dev: adapter [%s] registered as minor %d\n", adap->name, adap->nr); /* register this i2c device with the driver core */ i2c_dev->class_dev = class_device_create(i2c_dev_class, NULL, MKDEV(I2C_MAJOR, adap->nr), &adap->dev, "i2c-%d", adap->nr); if (!i2c_dev->class_dev) goto error; class_device_create_file(i2c_dev->class_dev, &class_device_attr_name); return 0; error: return_i2c_dev(i2c_dev); kfree(i2c_dev); return -ENODEV; } static int i2cdev_detach_adapter(struct i2c_adapter *adap) { struct i2c_dev *i2c_dev; i2c_dev = i2c_dev_get_by_minor(adap->nr); if (!i2c_dev) return -ENODEV; return_i2c_dev(i2c_dev); class_device_destroy(i2c_dev_class, MKDEV(I2C_MAJOR, adap->nr)); kfree(i2c_dev); pr_debug("i2c-dev: adapter [%s] unregistered\n", adap->name); return 0; } static int i2cdev_detach_client(struct i2c_client *client) { return 0; } static struct i2c_driver i2cdev_driver = { .driver = { .name = "dev_driver", }, .id = I2C_DRIVERID_I2CDEV, .attach_adapter = i2cdev_attach_adapter, .detach_adapter = i2cdev_detach_adapter, .detach_client = i2cdev_detach_client, }; static int __init i2c_dev_init(void) { int res; printk(KERN_INFO "i2c /dev entries driver\n"); res = register_chrdev(I2C_MAJOR, "i2c", &i2cdev_fops); if (res) goto out; i2c_dev_class = class_create(THIS_MODULE, "i2c-dev"); if (IS_ERR(i2c_dev_class)) goto out_unreg_chrdev; res = i2c_add_driver(&i2cdev_driver); if (res) goto out_unreg_class; return 0; out_unreg_class: class_destroy(i2c_dev_class); out_unreg_chrdev: unregister_chrdev(I2C_MAJOR, "i2c"); out: printk(KERN_ERR "%s: Driver Initialisation failed\n", __FILE__); return res; } static void __exit i2c_dev_exit(void) { i2c_del_driver(&i2cdev_driver); class_destroy(i2c_dev_class); unregister_chrdev(I2C_MAJOR,"i2c"); } MODULE_AUTHOR("Frodo Looijaard and " "Simon G. Vogl "); MODULE_DESCRIPTION("I2C /dev entries driver"); MODULE_LICENSE("GPL"); module_init(i2c_dev_init); module_exit(i2c_dev_exit);