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1413ef638a
The struct cdev is embedded in the struct i2c_dev. In the current code, we would free the i2c_dev struct directly in put_i2c_dev(), but the cdev is manged by a kobject, and the release of it is not predictable. So it is very possible that the i2c_dev is freed before the cdev is entirely released. We can easily get the following call trace with CONFIG_DEBUG_KOBJECT_RELEASE and CONFIG_DEBUG_OBJECTS_TIMERS enabled. ODEBUG: free active (active state 0) object type: timer_list hint: delayed_work_timer_fn+0x0/0x38 WARNING: CPU: 19 PID: 1 at lib/debugobjects.c:325 debug_print_object+0xb0/0xf0 Modules linked in: CPU: 19 PID: 1 Comm: swapper/0 Tainted: G W 5.2.20-yocto-standard+ #120 Hardware name: Marvell OcteonTX CN96XX board (DT) pstate: 80c00089 (Nzcv daIf +PAN +UAO) pc : debug_print_object+0xb0/0xf0 lr : debug_print_object+0xb0/0xf0 sp : ffff00001292f7d0 x29: ffff00001292f7d0 x28: ffff800b82151788 x27: 0000000000000001 x26: ffff800b892c0000 x25: ffff0000124a2558 x24: 0000000000000000 x23: ffff00001107a1d8 x22: ffff0000116b5088 x21: ffff800bdc6afca8 x20: ffff000012471ae8 x19: ffff00001168f2c8 x18: 0000000000000010 x17: 00000000fd6f304b x16: 00000000ee79de43 x15: ffff800bc0e80568 x14: 79616c6564203a74 x13: 6e6968207473696c x12: 5f72656d6974203a x11: ffff0000113f0018 x10: 0000000000000000 x9 : 000000000000001f x8 : 0000000000000000 x7 : ffff0000101294cc x6 : 0000000000000000 x5 : 0000000000000000 x4 : 0000000000000001 x3 : 00000000ffffffff x2 : 0000000000000000 x1 : 387fc15c8ec0f200 x0 : 0000000000000000 Call trace: debug_print_object+0xb0/0xf0 __debug_check_no_obj_freed+0x19c/0x228 debug_check_no_obj_freed+0x1c/0x28 kfree+0x250/0x440 put_i2c_dev+0x68/0x78 i2cdev_detach_adapter+0x60/0xc8 i2cdev_notifier_call+0x3c/0x70 notifier_call_chain+0x8c/0xe8 blocking_notifier_call_chain+0x64/0x88 device_del+0x74/0x380 device_unregister+0x54/0x78 i2c_del_adapter+0x278/0x2d0 unittest_i2c_bus_remove+0x3c/0x80 platform_drv_remove+0x30/0x50 device_release_driver_internal+0xf4/0x1c0 driver_detach+0x58/0xa0 bus_remove_driver+0x84/0xd8 driver_unregister+0x34/0x60 platform_driver_unregister+0x20/0x30 of_unittest_overlay+0x8d4/0xbe0 of_unittest+0xae8/0xb3c do_one_initcall+0xac/0x450 do_initcall_level+0x208/0x224 kernel_init_freeable+0x2d8/0x36c kernel_init+0x18/0x108 ret_from_fork+0x10/0x1c irq event stamp: 3934661 hardirqs last enabled at (3934661): [<ffff00001009fa04>] debug_exception_exit+0x4c/0x58 hardirqs last disabled at (3934660): [<ffff00001009fb14>] debug_exception_enter+0xa4/0xe0 softirqs last enabled at (3934654
): [<ffff000010081d94>] __do_softirq+0x46c/0x628 softirqs last disabled at (3934649): [<ffff0000100b4a1c>] irq_exit+0x104/0x118 This is a common issue when using cdev embedded in a struct. Fortunately, we already have a mechanism to solve this kind of issue. Please see commit233ed09d7f
("chardev: add helper function to register char devs with a struct device") for more detail. In this patch, we choose to embed the struct device into the i2c_dev, and use the API provided by the commit233ed09d7f
to make sure that the release of i2c_dev and cdev are in sequence. Signed-off-by: Kevin Hao <haokexin@gmail.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
771 lines
19 KiB
C
771 lines
19 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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i2c-dev.c - i2c-bus driver, char device interface
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Copyright (C) 1995-97 Simon G. Vogl
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Copyright (C) 1998-99 Frodo Looijaard <frodol@dds.nl>
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Copyright (C) 2003 Greg Kroah-Hartman <greg@kroah.com>
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*/
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/* Note that this is a complete rewrite of Simon Vogl's i2c-dev module.
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But I have used so much of his original code and ideas that it seems
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only fair to recognize him as co-author -- Frodo */
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/* The I2C_RDWR ioctl code is written by Kolja Waschk <waschk@telos.de> */
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#include <linux/cdev.h>
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#include <linux/compat.h>
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#include <linux/device.h>
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#include <linux/fs.h>
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#include <linux/i2c-dev.h>
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#include <linux/i2c.h>
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#include <linux/init.h>
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#include <linux/jiffies.h>
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#include <linux/kernel.h>
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#include <linux/list.h>
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#include <linux/module.h>
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#include <linux/notifier.h>
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#include <linux/slab.h>
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#include <linux/uaccess.h>
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/*
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* An i2c_dev represents an i2c_adapter ... an I2C or SMBus master, not a
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* slave (i2c_client) with which messages will be exchanged. It's coupled
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* with a character special file which is accessed by user mode drivers.
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*
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* The list of i2c_dev structures is parallel to the i2c_adapter lists
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* maintained by the driver model, and is updated using bus notifications.
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*/
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struct i2c_dev {
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struct list_head list;
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struct i2c_adapter *adap;
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struct device dev;
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struct cdev cdev;
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};
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#define I2C_MINORS (MINORMASK + 1)
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static LIST_HEAD(i2c_dev_list);
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static DEFINE_SPINLOCK(i2c_dev_list_lock);
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static struct i2c_dev *i2c_dev_get_by_minor(unsigned index)
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{
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struct i2c_dev *i2c_dev;
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spin_lock(&i2c_dev_list_lock);
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list_for_each_entry(i2c_dev, &i2c_dev_list, list) {
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if (i2c_dev->adap->nr == index)
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goto found;
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}
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i2c_dev = NULL;
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found:
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spin_unlock(&i2c_dev_list_lock);
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return i2c_dev;
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}
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static struct i2c_dev *get_free_i2c_dev(struct i2c_adapter *adap)
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{
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struct i2c_dev *i2c_dev;
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if (adap->nr >= I2C_MINORS) {
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printk(KERN_ERR "i2c-dev: Out of device minors (%d)\n",
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adap->nr);
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return ERR_PTR(-ENODEV);
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}
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i2c_dev = kzalloc(sizeof(*i2c_dev), GFP_KERNEL);
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if (!i2c_dev)
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return ERR_PTR(-ENOMEM);
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i2c_dev->adap = adap;
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spin_lock(&i2c_dev_list_lock);
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list_add_tail(&i2c_dev->list, &i2c_dev_list);
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spin_unlock(&i2c_dev_list_lock);
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return i2c_dev;
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}
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static void put_i2c_dev(struct i2c_dev *i2c_dev, bool del_cdev)
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{
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spin_lock(&i2c_dev_list_lock);
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list_del(&i2c_dev->list);
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spin_unlock(&i2c_dev_list_lock);
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if (del_cdev)
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cdev_device_del(&i2c_dev->cdev, &i2c_dev->dev);
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put_device(&i2c_dev->dev);
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}
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static ssize_t name_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct i2c_dev *i2c_dev = i2c_dev_get_by_minor(MINOR(dev->devt));
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if (!i2c_dev)
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return -ENODEV;
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return sprintf(buf, "%s\n", i2c_dev->adap->name);
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}
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static DEVICE_ATTR_RO(name);
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static struct attribute *i2c_attrs[] = {
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&dev_attr_name.attr,
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NULL,
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};
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ATTRIBUTE_GROUPS(i2c);
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/* ------------------------------------------------------------------------- */
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/*
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* After opening an instance of this character special file, a file
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* descriptor starts out associated only with an i2c_adapter (and bus).
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*
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* Using the I2C_RDWR ioctl(), you can then *immediately* issue i2c_msg
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* traffic to any devices on the bus used by that adapter. That's because
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* the i2c_msg vectors embed all the addressing information they need, and
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* are submitted directly to an i2c_adapter. However, SMBus-only adapters
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* don't support that interface.
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*
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* To use read()/write() system calls on that file descriptor, or to use
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* SMBus interfaces (and work with SMBus-only hosts!), you must first issue
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* an I2C_SLAVE (or I2C_SLAVE_FORCE) ioctl. That configures an anonymous
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* (never registered) i2c_client so it holds the addressing information
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* needed by those system calls and by this SMBus interface.
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*/
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static ssize_t i2cdev_read(struct file *file, char __user *buf, size_t count,
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loff_t *offset)
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{
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char *tmp;
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int ret;
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struct i2c_client *client = file->private_data;
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if (count > 8192)
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count = 8192;
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tmp = kmalloc(count, GFP_KERNEL);
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if (tmp == NULL)
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return -ENOMEM;
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pr_debug("i2c-dev: i2c-%d reading %zu bytes.\n",
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iminor(file_inode(file)), count);
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ret = i2c_master_recv(client, tmp, count);
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if (ret >= 0)
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ret = copy_to_user(buf, tmp, count) ? -EFAULT : ret;
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kfree(tmp);
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return ret;
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}
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static ssize_t i2cdev_write(struct file *file, const char __user *buf,
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size_t count, loff_t *offset)
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{
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int ret;
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char *tmp;
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struct i2c_client *client = file->private_data;
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if (count > 8192)
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count = 8192;
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tmp = memdup_user(buf, count);
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if (IS_ERR(tmp))
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return PTR_ERR(tmp);
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pr_debug("i2c-dev: i2c-%d writing %zu bytes.\n",
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iminor(file_inode(file)), count);
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ret = i2c_master_send(client, tmp, count);
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kfree(tmp);
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return ret;
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}
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static int i2cdev_check(struct device *dev, void *addrp)
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{
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struct i2c_client *client = i2c_verify_client(dev);
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if (!client || client->addr != *(unsigned int *)addrp)
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return 0;
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return dev->driver ? -EBUSY : 0;
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}
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/* walk up mux tree */
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static int i2cdev_check_mux_parents(struct i2c_adapter *adapter, int addr)
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{
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struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
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int result;
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result = device_for_each_child(&adapter->dev, &addr, i2cdev_check);
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if (!result && parent)
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result = i2cdev_check_mux_parents(parent, addr);
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return result;
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}
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/* recurse down mux tree */
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static int i2cdev_check_mux_children(struct device *dev, void *addrp)
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{
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int result;
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if (dev->type == &i2c_adapter_type)
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result = device_for_each_child(dev, addrp,
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i2cdev_check_mux_children);
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else
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result = i2cdev_check(dev, addrp);
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return result;
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}
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/* This address checking function differs from the one in i2c-core
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in that it considers an address with a registered device, but no
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driver bound to it, as NOT busy. */
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static int i2cdev_check_addr(struct i2c_adapter *adapter, unsigned int addr)
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{
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struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
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int result = 0;
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if (parent)
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result = i2cdev_check_mux_parents(parent, addr);
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if (!result)
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result = device_for_each_child(&adapter->dev, &addr,
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i2cdev_check_mux_children);
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return result;
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}
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static noinline int i2cdev_ioctl_rdwr(struct i2c_client *client,
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unsigned nmsgs, struct i2c_msg *msgs)
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{
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u8 __user **data_ptrs;
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int i, res;
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data_ptrs = kmalloc_array(nmsgs, sizeof(u8 __user *), GFP_KERNEL);
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if (data_ptrs == NULL) {
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kfree(msgs);
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return -ENOMEM;
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}
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res = 0;
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for (i = 0; i < nmsgs; i++) {
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/* Limit the size of the message to a sane amount */
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if (msgs[i].len > 8192) {
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res = -EINVAL;
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break;
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}
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data_ptrs[i] = (u8 __user *)msgs[i].buf;
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msgs[i].buf = memdup_user(data_ptrs[i], msgs[i].len);
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if (IS_ERR(msgs[i].buf)) {
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res = PTR_ERR(msgs[i].buf);
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break;
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}
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/* memdup_user allocates with GFP_KERNEL, so DMA is ok */
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msgs[i].flags |= I2C_M_DMA_SAFE;
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/*
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* If the message length is received from the slave (similar
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* to SMBus block read), we must ensure that the buffer will
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* be large enough to cope with a message length of
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* I2C_SMBUS_BLOCK_MAX as this is the maximum underlying bus
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* drivers allow. The first byte in the buffer must be
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* pre-filled with the number of extra bytes, which must be
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* at least one to hold the message length, but can be
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* greater (for example to account for a checksum byte at
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* the end of the message.)
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*/
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if (msgs[i].flags & I2C_M_RECV_LEN) {
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if (!(msgs[i].flags & I2C_M_RD) ||
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msgs[i].len < 1 || msgs[i].buf[0] < 1 ||
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msgs[i].len < msgs[i].buf[0] +
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I2C_SMBUS_BLOCK_MAX) {
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i++;
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res = -EINVAL;
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break;
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}
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msgs[i].len = msgs[i].buf[0];
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}
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}
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if (res < 0) {
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int j;
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for (j = 0; j < i; ++j)
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kfree(msgs[j].buf);
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kfree(data_ptrs);
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kfree(msgs);
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return res;
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}
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res = i2c_transfer(client->adapter, msgs, nmsgs);
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while (i-- > 0) {
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if (res >= 0 && (msgs[i].flags & I2C_M_RD)) {
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if (copy_to_user(data_ptrs[i], msgs[i].buf,
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msgs[i].len))
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res = -EFAULT;
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}
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kfree(msgs[i].buf);
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}
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kfree(data_ptrs);
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kfree(msgs);
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return res;
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}
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static noinline int i2cdev_ioctl_smbus(struct i2c_client *client,
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u8 read_write, u8 command, u32 size,
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union i2c_smbus_data __user *data)
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{
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union i2c_smbus_data temp = {};
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int datasize, res;
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if ((size != I2C_SMBUS_BYTE) &&
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(size != I2C_SMBUS_QUICK) &&
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(size != I2C_SMBUS_BYTE_DATA) &&
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(size != I2C_SMBUS_WORD_DATA) &&
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(size != I2C_SMBUS_PROC_CALL) &&
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(size != I2C_SMBUS_BLOCK_DATA) &&
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(size != I2C_SMBUS_I2C_BLOCK_BROKEN) &&
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(size != I2C_SMBUS_I2C_BLOCK_DATA) &&
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(size != I2C_SMBUS_BLOCK_PROC_CALL)) {
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dev_dbg(&client->adapter->dev,
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"size out of range (%x) in ioctl I2C_SMBUS.\n",
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size);
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return -EINVAL;
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}
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/* Note that I2C_SMBUS_READ and I2C_SMBUS_WRITE are 0 and 1,
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so the check is valid if size==I2C_SMBUS_QUICK too. */
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if ((read_write != I2C_SMBUS_READ) &&
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(read_write != I2C_SMBUS_WRITE)) {
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dev_dbg(&client->adapter->dev,
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"read_write out of range (%x) in ioctl I2C_SMBUS.\n",
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read_write);
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return -EINVAL;
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}
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/* Note that command values are always valid! */
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if ((size == I2C_SMBUS_QUICK) ||
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((size == I2C_SMBUS_BYTE) &&
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(read_write == I2C_SMBUS_WRITE)))
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/* These are special: we do not use data */
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return i2c_smbus_xfer(client->adapter, client->addr,
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client->flags, read_write,
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command, size, NULL);
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if (data == NULL) {
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dev_dbg(&client->adapter->dev,
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"data is NULL pointer in ioctl I2C_SMBUS.\n");
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return -EINVAL;
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}
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if ((size == I2C_SMBUS_BYTE_DATA) ||
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(size == I2C_SMBUS_BYTE))
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datasize = sizeof(data->byte);
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else if ((size == I2C_SMBUS_WORD_DATA) ||
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(size == I2C_SMBUS_PROC_CALL))
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datasize = sizeof(data->word);
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else /* size == smbus block, i2c block, or block proc. call */
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datasize = sizeof(data->block);
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if ((size == I2C_SMBUS_PROC_CALL) ||
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(size == I2C_SMBUS_BLOCK_PROC_CALL) ||
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(size == I2C_SMBUS_I2C_BLOCK_DATA) ||
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(read_write == I2C_SMBUS_WRITE)) {
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if (copy_from_user(&temp, data, datasize))
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return -EFAULT;
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}
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if (size == I2C_SMBUS_I2C_BLOCK_BROKEN) {
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/* Convert old I2C block commands to the new
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convention. This preserves binary compatibility. */
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size = I2C_SMBUS_I2C_BLOCK_DATA;
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if (read_write == I2C_SMBUS_READ)
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temp.block[0] = I2C_SMBUS_BLOCK_MAX;
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}
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res = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
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read_write, command, size, &temp);
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if (!res && ((size == I2C_SMBUS_PROC_CALL) ||
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(size == I2C_SMBUS_BLOCK_PROC_CALL) ||
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(read_write == I2C_SMBUS_READ))) {
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if (copy_to_user(data, &temp, datasize))
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return -EFAULT;
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}
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return res;
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}
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static long i2cdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
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{
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struct i2c_client *client = file->private_data;
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unsigned long funcs;
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dev_dbg(&client->adapter->dev, "ioctl, cmd=0x%02x, arg=0x%02lx\n",
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cmd, arg);
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switch (cmd) {
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case I2C_SLAVE:
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case I2C_SLAVE_FORCE:
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if ((arg > 0x3ff) ||
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(((client->flags & I2C_M_TEN) == 0) && arg > 0x7f))
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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:
|
|
/*
|
|
* 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)
|
|
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: {
|
|
struct i2c_rdwr_ioctl_data rdwr_arg;
|
|
struct i2c_msg *rdwr_pa;
|
|
|
|
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_RDWR_IOCTL_MAX_MSGS)
|
|
return -EINVAL;
|
|
|
|
rdwr_pa = memdup_user(rdwr_arg.msgs,
|
|
rdwr_arg.nmsgs * sizeof(struct i2c_msg));
|
|
if (IS_ERR(rdwr_pa))
|
|
return PTR_ERR(rdwr_pa);
|
|
|
|
return i2cdev_ioctl_rdwr(client, rdwr_arg.nmsgs, rdwr_pa);
|
|
}
|
|
|
|
case I2C_SMBUS: {
|
|
struct i2c_smbus_ioctl_data data_arg;
|
|
if (copy_from_user(&data_arg,
|
|
(struct i2c_smbus_ioctl_data __user *) arg,
|
|
sizeof(struct i2c_smbus_ioctl_data)))
|
|
return -EFAULT;
|
|
return i2cdev_ioctl_smbus(client, data_arg.read_write,
|
|
data_arg.command,
|
|
data_arg.size,
|
|
data_arg.data);
|
|
}
|
|
case I2C_RETRIES:
|
|
if (arg > INT_MAX)
|
|
return -EINVAL;
|
|
|
|
client->adapter->retries = arg;
|
|
break;
|
|
case I2C_TIMEOUT:
|
|
if (arg > INT_MAX)
|
|
return -EINVAL;
|
|
|
|
/* For historical reasons, user-space sets the timeout
|
|
* value in units of 10 ms.
|
|
*/
|
|
client->adapter->timeout = msecs_to_jiffies(arg * 10);
|
|
break;
|
|
default:
|
|
/* 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;
|
|
}
|
|
|
|
#ifdef CONFIG_COMPAT
|
|
|
|
struct i2c_smbus_ioctl_data32 {
|
|
u8 read_write;
|
|
u8 command;
|
|
u32 size;
|
|
compat_caddr_t data; /* union i2c_smbus_data *data */
|
|
};
|
|
|
|
struct i2c_msg32 {
|
|
u16 addr;
|
|
u16 flags;
|
|
u16 len;
|
|
compat_caddr_t buf;
|
|
};
|
|
|
|
struct i2c_rdwr_ioctl_data32 {
|
|
compat_caddr_t msgs; /* struct i2c_msg __user *msgs */
|
|
u32 nmsgs;
|
|
};
|
|
|
|
static long compat_i2cdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
|
|
{
|
|
struct i2c_client *client = file->private_data;
|
|
unsigned long funcs;
|
|
switch (cmd) {
|
|
case I2C_FUNCS:
|
|
funcs = i2c_get_functionality(client->adapter);
|
|
return put_user(funcs, (compat_ulong_t __user *)arg);
|
|
case I2C_RDWR: {
|
|
struct i2c_rdwr_ioctl_data32 rdwr_arg;
|
|
struct i2c_msg32 *p;
|
|
struct i2c_msg *rdwr_pa;
|
|
int i;
|
|
|
|
if (copy_from_user(&rdwr_arg,
|
|
(struct i2c_rdwr_ioctl_data32 __user *)arg,
|
|
sizeof(rdwr_arg)))
|
|
return -EFAULT;
|
|
|
|
if (rdwr_arg.nmsgs > I2C_RDWR_IOCTL_MAX_MSGS)
|
|
return -EINVAL;
|
|
|
|
rdwr_pa = kmalloc_array(rdwr_arg.nmsgs, sizeof(struct i2c_msg),
|
|
GFP_KERNEL);
|
|
if (!rdwr_pa)
|
|
return -ENOMEM;
|
|
|
|
p = compat_ptr(rdwr_arg.msgs);
|
|
for (i = 0; i < rdwr_arg.nmsgs; i++) {
|
|
struct i2c_msg32 umsg;
|
|
if (copy_from_user(&umsg, p + i, sizeof(umsg))) {
|
|
kfree(rdwr_pa);
|
|
return -EFAULT;
|
|
}
|
|
rdwr_pa[i] = (struct i2c_msg) {
|
|
.addr = umsg.addr,
|
|
.flags = umsg.flags,
|
|
.len = umsg.len,
|
|
.buf = compat_ptr(umsg.buf)
|
|
};
|
|
}
|
|
|
|
return i2cdev_ioctl_rdwr(client, rdwr_arg.nmsgs, rdwr_pa);
|
|
}
|
|
case I2C_SMBUS: {
|
|
struct i2c_smbus_ioctl_data32 data32;
|
|
if (copy_from_user(&data32,
|
|
(void __user *) arg,
|
|
sizeof(data32)))
|
|
return -EFAULT;
|
|
return i2cdev_ioctl_smbus(client, data32.read_write,
|
|
data32.command,
|
|
data32.size,
|
|
compat_ptr(data32.data));
|
|
}
|
|
default:
|
|
return i2cdev_ioctl(file, cmd, arg);
|
|
}
|
|
}
|
|
#else
|
|
#define compat_i2cdev_ioctl NULL
|
|
#endif
|
|
|
|
static int i2cdev_open(struct inode *inode, struct file *file)
|
|
{
|
|
unsigned int minor = iminor(inode);
|
|
struct i2c_client *client;
|
|
struct i2c_adapter *adap;
|
|
|
|
adap = i2c_get_adapter(minor);
|
|
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);
|
|
return -ENOMEM;
|
|
}
|
|
snprintf(client->name, I2C_NAME_SIZE, "i2c-dev %d", adap->nr);
|
|
|
|
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 const struct file_operations i2cdev_fops = {
|
|
.owner = THIS_MODULE,
|
|
.llseek = no_llseek,
|
|
.read = i2cdev_read,
|
|
.write = i2cdev_write,
|
|
.unlocked_ioctl = i2cdev_ioctl,
|
|
.compat_ioctl = compat_i2cdev_ioctl,
|
|
.open = i2cdev_open,
|
|
.release = i2cdev_release,
|
|
};
|
|
|
|
/* ------------------------------------------------------------------------- */
|
|
|
|
static struct class *i2c_dev_class;
|
|
|
|
static void i2cdev_dev_release(struct device *dev)
|
|
{
|
|
struct i2c_dev *i2c_dev;
|
|
|
|
i2c_dev = container_of(dev, struct i2c_dev, dev);
|
|
kfree(i2c_dev);
|
|
}
|
|
|
|
static int i2cdev_attach_adapter(struct device *dev, void *dummy)
|
|
{
|
|
struct i2c_adapter *adap;
|
|
struct i2c_dev *i2c_dev;
|
|
int res;
|
|
|
|
if (dev->type != &i2c_adapter_type)
|
|
return 0;
|
|
adap = to_i2c_adapter(dev);
|
|
|
|
i2c_dev = get_free_i2c_dev(adap);
|
|
if (IS_ERR(i2c_dev))
|
|
return PTR_ERR(i2c_dev);
|
|
|
|
cdev_init(&i2c_dev->cdev, &i2cdev_fops);
|
|
i2c_dev->cdev.owner = THIS_MODULE;
|
|
|
|
device_initialize(&i2c_dev->dev);
|
|
i2c_dev->dev.devt = MKDEV(I2C_MAJOR, adap->nr);
|
|
i2c_dev->dev.class = i2c_dev_class;
|
|
i2c_dev->dev.parent = &adap->dev;
|
|
i2c_dev->dev.release = i2cdev_dev_release;
|
|
dev_set_name(&i2c_dev->dev, "i2c-%d", adap->nr);
|
|
|
|
res = cdev_device_add(&i2c_dev->cdev, &i2c_dev->dev);
|
|
if (res) {
|
|
put_i2c_dev(i2c_dev, false);
|
|
return res;
|
|
}
|
|
|
|
pr_debug("i2c-dev: adapter [%s] registered as minor %d\n",
|
|
adap->name, adap->nr);
|
|
return 0;
|
|
}
|
|
|
|
static int i2cdev_detach_adapter(struct device *dev, void *dummy)
|
|
{
|
|
struct i2c_adapter *adap;
|
|
struct i2c_dev *i2c_dev;
|
|
|
|
if (dev->type != &i2c_adapter_type)
|
|
return 0;
|
|
adap = to_i2c_adapter(dev);
|
|
|
|
i2c_dev = i2c_dev_get_by_minor(adap->nr);
|
|
if (!i2c_dev) /* attach_adapter must have failed */
|
|
return 0;
|
|
|
|
put_i2c_dev(i2c_dev, true);
|
|
|
|
pr_debug("i2c-dev: adapter [%s] unregistered\n", adap->name);
|
|
return 0;
|
|
}
|
|
|
|
static int i2cdev_notifier_call(struct notifier_block *nb, unsigned long action,
|
|
void *data)
|
|
{
|
|
struct device *dev = data;
|
|
|
|
switch (action) {
|
|
case BUS_NOTIFY_ADD_DEVICE:
|
|
return i2cdev_attach_adapter(dev, NULL);
|
|
case BUS_NOTIFY_DEL_DEVICE:
|
|
return i2cdev_detach_adapter(dev, NULL);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct notifier_block i2cdev_notifier = {
|
|
.notifier_call = i2cdev_notifier_call,
|
|
};
|
|
|
|
/* ------------------------------------------------------------------------- */
|
|
|
|
/*
|
|
* module load/unload record keeping
|
|
*/
|
|
|
|
static int __init i2c_dev_init(void)
|
|
{
|
|
int res;
|
|
|
|
printk(KERN_INFO "i2c /dev entries driver\n");
|
|
|
|
res = register_chrdev_region(MKDEV(I2C_MAJOR, 0), I2C_MINORS, "i2c");
|
|
if (res)
|
|
goto out;
|
|
|
|
i2c_dev_class = class_create(THIS_MODULE, "i2c-dev");
|
|
if (IS_ERR(i2c_dev_class)) {
|
|
res = PTR_ERR(i2c_dev_class);
|
|
goto out_unreg_chrdev;
|
|
}
|
|
i2c_dev_class->dev_groups = i2c_groups;
|
|
|
|
/* Keep track of adapters which will be added or removed later */
|
|
res = bus_register_notifier(&i2c_bus_type, &i2cdev_notifier);
|
|
if (res)
|
|
goto out_unreg_class;
|
|
|
|
/* Bind to already existing adapters right away */
|
|
i2c_for_each_dev(NULL, i2cdev_attach_adapter);
|
|
|
|
return 0;
|
|
|
|
out_unreg_class:
|
|
class_destroy(i2c_dev_class);
|
|
out_unreg_chrdev:
|
|
unregister_chrdev_region(MKDEV(I2C_MAJOR, 0), I2C_MINORS);
|
|
out:
|
|
printk(KERN_ERR "%s: Driver Initialisation failed\n", __FILE__);
|
|
return res;
|
|
}
|
|
|
|
static void __exit i2c_dev_exit(void)
|
|
{
|
|
bus_unregister_notifier(&i2c_bus_type, &i2cdev_notifier);
|
|
i2c_for_each_dev(NULL, i2cdev_detach_adapter);
|
|
class_destroy(i2c_dev_class);
|
|
unregister_chrdev_region(MKDEV(I2C_MAJOR, 0), I2C_MINORS);
|
|
}
|
|
|
|
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);
|