| /* |
| i2c-dev.c - i2c-bus driver, char device interface |
| |
| Copyright (C) 1995-97 Simon G. Vogl |
| Copyright (C) 1998-99 Frodo Looijaard <frodol@dds.nl> |
| Copyright (C) 2003 Greg Kroah-Hartman <greg@kroah.com> |
| |
| 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 <waschk@telos.de> */ |
| |
| /* The devfs code is contributed by Philipp Matthias Hahn |
| <pmhahn@titan.lahn.de> */ |
| |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/fs.h> |
| #include <linux/slab.h> |
| #include <linux/smp_lock.h> |
| #include <linux/devfs_fs_kernel.h> |
| #include <linux/init.h> |
| #include <linux/i2c.h> |
| #include <linux/i2c-dev.h> |
| #include <asm/uaccess.h> |
| |
| static struct i2c_client i2cdev_client_template; |
| |
| struct i2c_dev { |
| int minor; |
| struct i2c_adapter *adap; |
| struct class_device class_dev; |
| struct completion released; /* FIXME, we need a class_device_unregister() */ |
| }; |
| #define to_i2c_dev(d) container_of(d, struct i2c_dev, class_dev) |
| |
| #define I2C_MINORS 256 |
| static struct i2c_dev *i2c_dev_array[I2C_MINORS]; |
| static DEFINE_SPINLOCK(i2c_dev_array_lock); |
| |
| static struct i2c_dev *i2c_dev_get_by_minor(unsigned index) |
| { |
| struct i2c_dev *i2c_dev; |
| |
| spin_lock(&i2c_dev_array_lock); |
| i2c_dev = i2c_dev_array[index]; |
| spin_unlock(&i2c_dev_array_lock); |
| return i2c_dev; |
| } |
| |
| static struct i2c_dev *i2c_dev_get_by_adapter(struct i2c_adapter *adap) |
| { |
| struct i2c_dev *i2c_dev = NULL; |
| |
| spin_lock(&i2c_dev_array_lock); |
| if ((i2c_dev_array[adap->nr]) && |
| (i2c_dev_array[adap->nr]->adap == adap)) |
| i2c_dev = i2c_dev_array[adap->nr]; |
| spin_unlock(&i2c_dev_array_lock); |
| return i2c_dev; |
| } |
| |
| static struct i2c_dev *get_free_i2c_dev(struct i2c_adapter *adap) |
| { |
| struct i2c_dev *i2c_dev; |
| |
| i2c_dev = kmalloc(sizeof(*i2c_dev), GFP_KERNEL); |
| if (!i2c_dev) |
| return ERR_PTR(-ENOMEM); |
| memset(i2c_dev, 0x00, sizeof(*i2c_dev)); |
| |
| spin_lock(&i2c_dev_array_lock); |
| if (i2c_dev_array[adap->nr]) { |
| spin_unlock(&i2c_dev_array_lock); |
| dev_err(&adap->dev, "i2c-dev already has a device assigned to this adapter\n"); |
| goto error; |
| } |
| i2c_dev->minor = adap->nr; |
| i2c_dev_array[adap->nr] = i2c_dev; |
| spin_unlock(&i2c_dev_array_lock); |
| return i2c_dev; |
| error: |
| kfree(i2c_dev); |
| return ERR_PTR(-ENODEV); |
| } |
| |
| static void return_i2c_dev(struct i2c_dev *i2c_dev) |
| { |
| spin_lock(&i2c_dev_array_lock); |
| i2c_dev_array[i2c_dev->minor] = NULL; |
| spin_unlock(&i2c_dev_array_lock); |
| } |
| |
| static ssize_t show_adapter_name(struct class_device *class_dev, char *buf) |
| { |
| struct i2c_dev *i2c_dev = to_i2c_dev(class_dev); |
| 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, "i2c-%d ioctl, cmd: 0x%x, arg: %lx.\n", |
| iminor(inode),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 arbritrary 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<rdwr_arg.nmsgs; i++ ) { |
| /* Limit the size of the message to a sane amount */ |
| if (rdwr_pa[i].len > 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 = kmalloc(sizeof(*client), GFP_KERNEL); |
| if (!client) { |
| i2c_put_adapter(adap); |
| return -ENOMEM; |
| } |
| memcpy(client, &i2cdev_client_template, sizeof(*client)); |
| |
| /* 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 void release_i2c_dev(struct class_device *dev) |
| { |
| struct i2c_dev *i2c_dev = to_i2c_dev(dev); |
| complete(&i2c_dev->released); |
| } |
| |
| static struct class i2c_dev_class = { |
| .name = "i2c-dev", |
| .release = &release_i2c_dev, |
| }; |
| |
| static int i2cdev_attach_adapter(struct i2c_adapter *adap) |
| { |
| struct i2c_dev *i2c_dev; |
| int retval; |
| |
| i2c_dev = get_free_i2c_dev(adap); |
| if (IS_ERR(i2c_dev)) |
| return PTR_ERR(i2c_dev); |
| |
| devfs_mk_cdev(MKDEV(I2C_MAJOR, i2c_dev->minor), |
| S_IFCHR|S_IRUSR|S_IWUSR, "i2c/%d", i2c_dev->minor); |
| dev_dbg(&adap->dev, "Registered as minor %d\n", i2c_dev->minor); |
| |
| /* register this i2c device with the driver core */ |
| i2c_dev->adap = adap; |
| if (adap->dev.parent == &platform_bus) |
| i2c_dev->class_dev.dev = &adap->dev; |
| else |
| i2c_dev->class_dev.dev = adap->dev.parent; |
| i2c_dev->class_dev.class = &i2c_dev_class; |
| i2c_dev->class_dev.devt = MKDEV(I2C_MAJOR, i2c_dev->minor); |
| snprintf(i2c_dev->class_dev.class_id, BUS_ID_SIZE, "i2c-%d", i2c_dev->minor); |
| retval = class_device_register(&i2c_dev->class_dev); |
| if (retval) |
| 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 retval; |
| } |
| |
| static int i2cdev_detach_adapter(struct i2c_adapter *adap) |
| { |
| struct i2c_dev *i2c_dev; |
| |
| i2c_dev = i2c_dev_get_by_adapter(adap); |
| if (!i2c_dev) |
| return -ENODEV; |
| |
| init_completion(&i2c_dev->released); |
| devfs_remove("i2c/%d", i2c_dev->minor); |
| return_i2c_dev(i2c_dev); |
| class_device_unregister(&i2c_dev->class_dev); |
| wait_for_completion(&i2c_dev->released); |
| kfree(i2c_dev); |
| |
| dev_dbg(&adap->dev, "Adapter unregistered\n"); |
| return 0; |
| } |
| |
| static int i2cdev_detach_client(struct i2c_client *client) |
| { |
| return 0; |
| } |
| |
| static int i2cdev_command(struct i2c_client *client, unsigned int cmd, |
| void *arg) |
| { |
| return -1; |
| } |
| |
| static struct i2c_driver i2cdev_driver = { |
| .owner = THIS_MODULE, |
| .name = "dev_driver", |
| .id = I2C_DRIVERID_I2CDEV, |
| .flags = I2C_DF_NOTIFY, |
| .attach_adapter = i2cdev_attach_adapter, |
| .detach_adapter = i2cdev_detach_adapter, |
| .detach_client = i2cdev_detach_client, |
| .command = i2cdev_command, |
| }; |
| |
| static struct i2c_client i2cdev_client_template = { |
| .name = "I2C /dev entry", |
| .addr = -1, |
| .driver = &i2cdev_driver, |
| }; |
| |
| 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; |
| |
| res = class_register(&i2c_dev_class); |
| if (res) |
| goto out_unreg_chrdev; |
| |
| res = i2c_add_driver(&i2cdev_driver); |
| if (res) |
| goto out_unreg_class; |
| |
| devfs_mk_dir("i2c"); |
| |
| return 0; |
| |
| out_unreg_class: |
| class_unregister(&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_unregister(&i2c_dev_class); |
| devfs_remove("i2c"); |
| unregister_chrdev(I2C_MAJOR,"i2c"); |
| } |
| |
| MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl> and " |
| "Simon G. Vogl <simon@tk.uni-linz.ac.at>"); |
| MODULE_DESCRIPTION("I2C /dev entries driver"); |
| MODULE_LICENSE("GPL"); |
| |
| module_init(i2c_dev_init); |
| module_exit(i2c_dev_exit); |