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Commit dba7997a authored by Jean Delvare's avatar Jean Delvare Committed by Jean Delvare
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i2c-dev: Split i2cdev_ioctl 



Split the handling of the I2C_RDWR and I2C_SMBUS ioctls to their own
functions. This limits the stack usage, saves one level of indentation
and makes the code more readable.

Signed-off-by: default avatarJean Delvare <khali@linux-fr.org>
parent 838349b5

drivers/i2c/i2c-dev.c

+168 −161
Original line number Diff line number Diff line
@@ -200,59 +200,14 @@ 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)

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;

	unsigned long funcs;



	dev_dbg(&client->adapter->dev, "ioctl, cmd=0x%02x, arg=0x%02lx\n",

		cmd, arg);

	int i, res;



	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 && i2cdev_check_addr(client->adapter, arg))

			return -EBUSY;

		/* REVISIT: address could become busy later */

		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 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)))
@@ -266,8 +221,8 @@ static int i2cdev_ioctl(struct inode *inode, struct file *file, 
	rdwr_pa = (struct i2c_msg *)

		kmalloc(rdwr_arg.nmsgs * sizeof(struct i2c_msg),

		GFP_KERNEL);



		if (rdwr_pa == NULL) return -ENOMEM;

	if (!rdwr_pa)

		return -ENOMEM;



	if (copy_from_user(rdwr_pa, rdwr_arg.msgs,

			   rdwr_arg.nmsgs * sizeof(struct i2c_msg))) {
@@ -296,8 +251,7 @@ static int i2cdev_ioctl(struct inode *inode, struct file *file, 
			res = -ENOMEM;

			break;

		}

			if(copy_from_user(rdwr_pa[i].buf,

				data_ptrs[i],

		if (copy_from_user(rdwr_pa[i].buf, data_ptrs[i],

				   rdwr_pa[i].len)) {

				++i; /* Needs to be kfreed too */

				res = -EFAULT;
@@ -313,25 +267,27 @@ static int i2cdev_ioctl(struct inode *inode, struct file *file, 
		return res;

	}



		res = i2c_transfer(client->adapter,

			rdwr_pa,

			rdwr_arg.nmsgs);

	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)) {

			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;



	case I2C_SMBUS:

	if (copy_from_user(&data_arg,

			   (struct i2c_smbus_ioctl_data __user *) arg,

			   sizeof(struct i2c_smbus_ioctl_data)))
@@ -367,10 +323,8 @@ static int i2cdev_ioctl(struct inode *inode, struct file *file, 
	    (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);

				      client->flags, data_arg.read_write,

				      data_arg.command, data_arg.size, NULL);



	if (data_arg.data == NULL) {

		dev_dbg(&client->adapter->dev,
@@ -402,8 +356,7 @@ static int i2cdev_ioctl(struct inode *inode, struct file *file, 
			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);

	      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))) {
@@ -411,6 +364,60 @@ static int i2cdev_ioctl(struct inode *inode, struct file *file, 
			return -EFAULT;

	}

	return res;

}



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;

	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:

		/* 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 && i2cdev_check_addr(client->adapter, arg))

			return -EBUSY;

		/* REVISIT: address could become busy later */

		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 put_user(funcs, (unsigned long __user *)arg);



	case I2C_RDWR:

		return i2cdev_ioctl_rdrw(client, arg);



	case I2C_SMBUS:

		return i2cdev_ioctl_smbus(client, arg);



	case I2C_RETRIES:

		client->adapter->retries = arg;

		break;