/*
- i2c-dev.c - i2c-bus driver, char device interface
+ 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>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/slab.h>
-#include <linux/smp_lock.h>
#include <linux/init.h>
+#include <linux/list.h>
#include <linux/i2c.h>
#include <linux/i2c-dev.h>
-#include <linux/platform_device.h>
#include <asm/uaccess.h>
-static struct i2c_client i2cdev_client_template;
+static struct i2c_driver i2cdev_driver;
+/*
+ * An i2c_dev represents an i2c_adapter ... an I2C or SMBus master, not a
+ * slave (i2c_client) with which messages will be exchanged. It's coupled
+ * with a character special file which is accessed by user mode drivers.
+ *
+ * The list of i2c_dev structures is parallel to the i2c_adapter lists
+ * maintained by the driver model, and is updated using notifications
+ * delivered to the i2cdev_driver.
+ */
struct i2c_dev {
- int minor;
+ struct list_head list;
struct i2c_adapter *adap;
- struct class_device *class_dev;
+ struct device *dev;
};
-#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 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_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);
+ 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;
}
{
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_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);
+ spin_lock(&i2c_dev_list_lock);
+ list_add_tail(&i2c_dev->list, &i2c_dev_list);
+ spin_unlock(&i2c_dev_list_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);
+ spin_lock(&i2c_dev_list_lock);
+ list_del(&i2c_dev->list);
+ spin_unlock(&i2c_dev_list_lock);
+ kfree(i2c_dev);
}
-static ssize_t show_adapter_name(struct class_device *class_dev, char *buf)
+static ssize_t show_adapter_name(struct device *dev,
+ struct device_attribute *attr, char *buf)
{
- struct i2c_dev *i2c_dev = i2c_dev_get_by_minor(MINOR(class_dev->devt));
+ struct i2c_dev *i2c_dev = i2c_dev_get_by_minor(MINOR(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 DEVICE_ATTR(name, S_IRUGO, show_adapter_name, NULL);
+
+/* ------------------------------------------------------------------------- */
+
+/*
+ * After opening an instance of this character special file, a file
+ * descriptor starts out associated only with an i2c_adapter (and bus).
+ *
+ * Using the I2C_RDWR ioctl(), you can then *immediately* issue i2c_msg
+ * traffic to any devices on the bus used by that adapter. That's because
+ * the i2c_msg vectors embed all the addressing information they need, and
+ * are submitted directly to an i2c_adapter. However, SMBus-only adapters
+ * don't support that interface.
+ *
+ * To use read()/write() system calls on that file descriptor, or to use
+ * SMBus interfaces (and work with SMBus-only hosts!), you must first issue
+ * an I2C_SLAVE (or I2C_SLAVE_FORCE) ioctl. That configures an anonymous
+ * (never registered) i2c_client so it holds the addressing information
+ * needed by those system calls and by this SMBus interface.
+ */
static ssize_t i2cdev_read (struct file *file, char __user *buf, size_t count,
loff_t *offset)
return -ENOMEM;
pr_debug("i2c-dev: i2c-%d reading %zd bytes.\n",
- iminor(file->f_dentry->d_inode), count);
+ iminor(file->f_path.dentry->d_inode), count);
ret = i2c_master_recv(client,tmp,count);
if (ret >= 0)
}
pr_debug("i2c-dev: i2c-%d writing %zd bytes.\n",
- iminor(file->f_dentry->d_inode), count);
+ iminor(file->f_path.dentry->d_inode), count);
ret = i2c_master_send(client,tmp,count);
kfree(tmp);
return ret;
}
+static int i2cdev_check(struct device *dev, void *addrp)
+{
+ struct i2c_client *client = i2c_verify_client(dev);
+
+ if (!client || client->addr != *(unsigned int *)addrp)
+ return 0;
+
+ return dev->driver ? -EBUSY : 0;
+}
+
+/* This address checking function differs from the one in i2c-core
+ in that it considers an address with a registered device, but no
+ driver bound to it, as NOT busy. */
+static int i2cdev_check_addr(struct i2c_adapter *adapter, unsigned int addr)
+{
+ return device_for_each_child(&adapter->dev, &addr, i2cdev_check);
+}
+
static int i2cdev_ioctl(struct inode *inode, struct file *file,
unsigned int cmd, unsigned long arg)
{
switch ( cmd ) {
case I2C_SLAVE:
case I2C_SLAVE_FORCE:
- if ((arg > 0x3ff) ||
+ /* NOTE: devices set up to work with "new style" drivers
+ * can't use I2C_SLAVE, even when the device node is not
+ * bound to a driver. Only I2C_SLAVE_FORCE will work.
+ *
+ * Setting the PEC flag here won't affect kernel drivers,
+ * which will be using the i2c_client node registered with
+ * the driver model core. Likewise, when that client has
+ * the PEC flag already set, the i2c-dev driver won't see
+ * (or use) this setting.
+ */
+ if ((arg > 0x3ff) ||
(((client->flags & I2C_M_TEN) == 0) && arg > 0x7f))
return -EINVAL;
- if ((cmd == I2C_SLAVE) && i2c_check_addr(client->adapter,arg))
+ if (cmd == I2C_SLAVE && i2cdev_check_addr(client->adapter, arg))
return -EBUSY;
+ /* REVISIT: address could become busy later */
client->addr = arg;
return 0;
case I2C_TENBIT:
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;
+ return put_user(funcs, (unsigned long __user *)arg);
case I2C_RDWR:
- if (copy_from_user(&rdwr_arg,
- (struct i2c_rdwr_ioctl_data __user *)arg,
+ if (copy_from_user(&rdwr_arg,
+ (struct i2c_rdwr_ioctl_data __user *)arg,
sizeof(rdwr_arg)))
return -EFAULT;
* 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),
+ kmalloc(rdwr_arg.nmsgs * sizeof(struct i2c_msg),
GFP_KERNEL);
if (rdwr_pa == NULL) 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) {
+ /* Limit the size of the message to a sane amount;
+ * and don't let length change either. */
+ if ((rdwr_pa[i].len > 8192) ||
+ (rdwr_pa[i].flags & I2C_M_RECV_LEN)) {
res = -EINVAL;
break;
}
(struct i2c_smbus_ioctl_data __user *) arg,
sizeof(struct i2c_smbus_ioctl_data)))
return -EFAULT;
- if ((data_arg.size != I2C_SMBUS_BYTE) &&
+ 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_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_BROKEN) &&
(data_arg.size != I2C_SMBUS_I2C_BLOCK_DATA) &&
(data_arg.size != I2C_SMBUS_BLOCK_PROC_CALL)) {
dev_dbg(&client->adapter->dev,
data_arg.size);
return -EINVAL;
}
- /* Note that I2C_SMBUS_READ and I2C_SMBUS_WRITE are 0 and 1,
+ /* 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) &&
+ if ((data_arg.read_write != I2C_SMBUS_READ) &&
(data_arg.read_write != I2C_SMBUS_WRITE)) {
- dev_dbg(&client->adapter->dev,
+ 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.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,
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) ||
+ 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) ||
+ if ((data_arg.size == I2C_SMBUS_PROC_CALL) ||
+ (data_arg.size == I2C_SMBUS_BLOCK_PROC_CALL) ||
+ (data_arg.size == I2C_SMBUS_I2C_BLOCK_DATA) ||
(data_arg.read_write == I2C_SMBUS_WRITE)) {
if (copy_from_user(&temp, data_arg.data, datasize))
return -EFAULT;
}
+ if (data_arg.size == I2C_SMBUS_I2C_BLOCK_BROKEN) {
+ /* Convert old I2C block commands to the new
+ convention. This preserves binary compatibility. */
+ data_arg.size = I2C_SMBUS_I2C_BLOCK_DATA;
+ if (data_arg.read_write == I2C_SMBUS_READ)
+ temp.block[0] = I2C_SMBUS_BLOCK_MAX;
+ }
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) ||
+ 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;
-
+ case I2C_RETRIES:
+ client->adapter->retries = arg;
+ break;
+ case I2C_TIMEOUT:
+ client->adapter->timeout = arg;
+ break;
default:
- return i2c_control(client,cmd,arg);
+ /* NOTE: returning a fault code here could cause trouble
+ * in buggy userspace code. Some old kernel bugs returned
+ * zero in this case, and userspace code might accidentally
+ * have depended on that bug.
+ */
+ return -ENOTTY;
}
return 0;
}
if (!adap)
return -ENODEV;
- client = kmalloc(sizeof(*client), GFP_KERNEL);
+ /* This creates an anonymous i2c_client, which may later be
+ * pointed to some address using I2C_SLAVE or I2C_SLAVE_FORCE.
+ *
+ * This client is ** NEVER REGISTERED ** with the driver model
+ * or I2C core code!! It just holds private copies of addressing
+ * information and maybe a PEC flag.
+ */
+ client = kzalloc(sizeof(*client), GFP_KERNEL);
if (!client) {
i2c_put_adapter(adap);
return -ENOMEM;
}
- memcpy(client, &i2cdev_client_template, sizeof(*client));
+ 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 struct file_operations i2cdev_fops = {
+static const struct file_operations i2cdev_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.read = i2cdev_read,
.release = i2cdev_release,
};
+/* ------------------------------------------------------------------------- */
+
+/*
+ * The legacy "i2cdev_driver" is used primarily to get notifications when
+ * I2C adapters are added or removed, so that each one gets an i2c_dev
+ * and is thus made available to userspace driver code.
+ */
+
static struct class *i2c_dev_class;
static int i2cdev_attach_adapter(struct i2c_adapter *adap)
{
struct i2c_dev *i2c_dev;
- struct device *dev;
+ int res;
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, i2c_dev->minor);
-
/* register this i2c device with the driver core */
- i2c_dev->adap = adap;
- if (adap->dev.parent == &platform_bus)
- dev = &adap->dev;
- else
- dev = adap->dev.parent;
- i2c_dev->class_dev = class_device_create(i2c_dev_class, NULL,
- MKDEV(I2C_MAJOR, i2c_dev->minor),
- dev, "i2c-%d", i2c_dev->minor);
- if (!i2c_dev->class_dev)
+ i2c_dev->dev = device_create(i2c_dev_class, &adap->dev,
+ MKDEV(I2C_MAJOR, adap->nr),
+ "i2c-%d", adap->nr);
+ if (IS_ERR(i2c_dev->dev)) {
+ res = PTR_ERR(i2c_dev->dev);
goto error;
- class_device_create_file(i2c_dev->class_dev, &class_device_attr_name);
+ }
+ res = device_create_file(i2c_dev->dev, &dev_attr_name);
+ if (res)
+ goto error_destroy;
+
+ pr_debug("i2c-dev: adapter [%s] registered as minor %d\n",
+ adap->name, adap->nr);
return 0;
+error_destroy:
+ device_destroy(i2c_dev_class, MKDEV(I2C_MAJOR, adap->nr));
error:
return_i2c_dev(i2c_dev);
- kfree(i2c_dev);
- return -ENODEV;
+ return res;
}
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;
+ i2c_dev = i2c_dev_get_by_minor(adap->nr);
+ if (!i2c_dev) /* attach_adapter must have failed */
+ return 0;
+ device_remove_file(i2c_dev->dev, &dev_attr_name);
return_i2c_dev(i2c_dev);
- class_device_destroy(i2c_dev_class, MKDEV(I2C_MAJOR, i2c_dev->minor));
- kfree(i2c_dev);
+ device_destroy(i2c_dev_class, MKDEV(I2C_MAJOR, adap->nr));
pr_debug("i2c-dev: adapter [%s] unregistered\n", adap->name);
return 0;
return 0;
}
-static int i2cdev_command(struct i2c_client *client, unsigned int cmd,
- void *arg)
-{
- return -1;
-}
-
static struct i2c_driver i2cdev_driver = {
.driver = {
.name = "dev_driver",
.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,
-};
+/* ------------------------------------------------------------------------- */
+
+/*
+ * module load/unload record keeping
+ */
static int __init i2c_dev_init(void)
{
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff