#include <linux/list.h>
#include <linux/i2c.h>
#include <linux/i2c-dev.h>
+#include <linux/jiffies.h>
#include <asm/uaccess.h>
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 {
struct list_head list;
struct i2c_adapter *adap;
}
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)
{
if (tmp==NULL)
return -ENOMEM;
- pr_debug("i2c-dev: i2c-%d reading %zd bytes.\n",
+ pr_debug("i2c-dev: i2c-%d reading %zu bytes.\n",
iminor(file->f_path.dentry->d_inode), count);
ret = i2c_master_recv(client,tmp,count);
return -EFAULT;
}
- pr_debug("i2c-dev: i2c-%d writing %zd bytes.\n",
+ pr_debug("i2c-dev: i2c-%d writing %zu bytes.\n",
iminor(file->f_path.dentry->d_inode), count);
ret = i2c_master_send(client,tmp,count);
return ret;
}
-static int i2cdev_ioctl(struct inode *inode, struct file *file,
- unsigned int cmd, unsigned long arg)
+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 noinline int i2cdev_ioctl_rdrw(struct i2c_client *client,
+ 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;
+ int i, res;
+
+ 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)
+ 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;
+ * and don't let length change either. */
+ if ((rdwr_pa[i].len > 8192) ||
+ (rdwr_pa[i].flags & I2C_M_RECV_LEN)) {
+ 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;
+}
+
+static noinline int i2cdev_ioctl_smbus(struct i2c_client *client,
+ unsigned long arg)
+{
+ struct i2c_smbus_ioctl_data data_arg;
+ union i2c_smbus_data temp;
+ int datasize, res;
+
+ 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_BROKEN) &&
+ (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.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) ||
+ (data_arg.read_write == I2C_SMBUS_READ))) {
+ if (copy_to_user(data_arg.data, &temp, datasize))
+ return -EFAULT;
+ }
+ return res;
+}
+
+static long i2cdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+ struct i2c_client *client = (struct i2c_client *)file->private_data;
unsigned long funcs;
dev_dbg(&client->adapter->dev, "ioctl, cmd=0x%02x, arg=0x%02lx\n",
switch ( cmd ) {
case I2C_SLAVE:
case I2C_SLAVE_FORCE:
+ /* 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 put_user(funcs, (unsigned long __user *)arg);
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<rdwr_arg.nmsgs; i++ ) {
- /* 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;
- }
- 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;
+ return i2cdev_ioctl_rdrw(client, arg);
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_BROKEN) &&
- (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.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) ||
- (data_arg.read_write == I2C_SMBUS_READ))) {
- if (copy_to_user(data_arg.data, &temp, datasize))
- return -EFAULT;
- }
- return res;
-
+ return i2cdev_ioctl_smbus(client, arg);
+
+ case I2C_RETRIES:
+ client->adapter->retries = arg;
+ break;
+ case I2C_TIMEOUT:
+ /* For historical reasons, user-space sets the timeout
+ * value in units of 10 ms.
+ */
+ client->adapter->timeout = msecs_to_jiffies(arg * 10);
+ 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;
+ /* 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);
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;
.llseek = no_llseek,
.read = i2cdev_read,
.write = i2cdev_write,
- .ioctl = i2cdev_ioctl,
+ .unlocked_ioctl = i2cdev_ioctl,
.open = i2cdev_open,
.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)
/* register this i2c device with the driver core */
i2c_dev->dev = device_create(i2c_dev_class, &adap->dev,
- MKDEV(I2C_MAJOR, adap->nr),
+ MKDEV(I2C_MAJOR, adap->nr), NULL,
"i2c-%d", adap->nr);
if (IS_ERR(i2c_dev->dev)) {
res = PTR_ERR(i2c_dev->dev);
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,
};
+/* ------------------------------------------------------------------------- */
+
+/*
+ * module load/unload record keeping
+ */
+
static int __init i2c_dev_init(void)
{
int res;
goto out;
i2c_dev_class = class_create(THIS_MODULE, "i2c-dev");
- if (IS_ERR(i2c_dev_class))
+ if (IS_ERR(i2c_dev_class)) {
+ res = PTR_ERR(i2c_dev_class);
goto out_unreg_chrdev;
+ }
res = i2c_add_driver(&i2cdev_driver);
if (res)
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff