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-rw-r--r--drivers/i2c/i2c-dev.c552
1 files changed, 552 insertions, 0 deletions
diff --git a/drivers/i2c/i2c-dev.c b/drivers/i2c/i2c-dev.c
new file mode 100644
index 000000000000..86c4d0149e82
--- /dev/null
+++ b/drivers/i2c/i2c-dev.c
@@ -0,0 +1,552 @@
+/*
+ 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/config.h>
+#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);
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.