X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=drivers%2Fi2c%2Fi2c-dev.c;h=393e679d9faac4f1a8351b69376ffc656474871d;hb=17159b0b494ad27f397f914d6eab1b91faf57630;hp=6e90dec02567a37d9ec262967ae4e1fa60393d16;hpb=9455e4c9abf76fa02170743859b2ddbb484e7fdf;p=safe%2Fjmp%2Flinux-2.6 diff --git a/drivers/i2c/i2c-dev.c b/drivers/i2c/i2c-dev.c index 6e90dec..393e679 100644 --- a/drivers/i2c/i2c-dev.c +++ b/drivers/i2c/i2c-dev.c @@ -1,5 +1,5 @@ /* - 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 @@ -30,30 +30,45 @@ #include #include #include -#include #include +#include #include #include #include -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 { + struct list_head list; struct i2c_adapter *adap; - struct class_device *class_dev; + struct device *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); + 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; } @@ -61,41 +76,60 @@ static struct i2c_dev *get_free_i2c_dev(struct i2c_adapter *adap) { 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); - - 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->adap = adap; - 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->adap->nr] = 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) @@ -113,7 +147,7 @@ static ssize_t i2cdev_read (struct file *file, char __user *buf, size_t count, 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) @@ -141,13 +175,31 @@ static ssize_t i2cdev_write (struct file *file, const char __user *buf, size_t c } 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) { @@ -166,11 +218,22 @@ static int i2cdev_ioctl(struct inode *inode, struct file *file, 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: @@ -187,12 +250,11 @@ static int i2cdev_ioctl(struct inode *inode, struct file *file, 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; @@ -200,9 +262,9 @@ static int i2cdev_ioctl(struct inode *inode, struct file *file, * 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; @@ -221,8 +283,10 @@ static int i2cdev_ioctl(struct inode *inode, struct file *file, res = 0; for( i=0; i 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; } @@ -272,12 +336,13 @@ static int i2cdev_ioctl(struct inode *inode, struct file *file, (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, @@ -285,11 +350,11 @@ static int i2cdev_ioctl(struct inode *inode, struct file *file, 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; @@ -298,7 +363,7 @@ static int i2cdev_ioctl(struct inode *inode, struct file *file, /* 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, @@ -316,31 +381,49 @@ static int i2cdev_ioctl(struct inode *inode, struct file *file, 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; } @@ -360,14 +443,21 @@ static int i2cdev_open(struct inode *inode, struct file *file) 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; @@ -385,7 +475,7 @@ static int i2cdev_release(struct inode *inode, struct file *file) return 0; } -static struct file_operations i2cdev_fops = { +static const struct file_operations i2cdev_fops = { .owner = THIS_MODULE, .llseek = no_llseek, .read = i2cdev_read, @@ -395,32 +485,45 @@ static struct file_operations i2cdev_fops = { .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; + 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, adap->nr); - /* register this i2c device with the driver core */ - i2c_dev->class_dev = class_device_create(i2c_dev_class, NULL, - MKDEV(I2C_MAJOR, adap->nr), - &adap->dev, "i2c-%d", - adap->nr); - 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) @@ -428,12 +531,12 @@ static int i2cdev_detach_adapter(struct i2c_adapter *adap) struct i2c_dev *i2c_dev; i2c_dev = i2c_dev_get_by_minor(adap->nr); - if (!i2c_dev) - return -ENODEV; + 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, adap->nr)); - 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; @@ -454,11 +557,11 @@ static struct i2c_driver i2cdev_driver = { .detach_client = i2cdev_detach_client, }; -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) {