linux/Documentation/i2c/old-module-parameters
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   1I2C device driver binding control from user-space
   2=================================================
   3
   4Up to kernel 2.6.32, many i2c drivers used helper macros provided by
   5<linux/i2c.h> which created standard module parameters to let the user
   6control how the driver would probe i2c buses and attach to devices. These
   7parameters were known as "probe" (to let the driver probe for an extra
   8address), "force" (to forcibly attach the driver to a given device) and
   9"ignore" (to prevent a driver from probing a given address).
  10
  11With the conversion of the i2c subsystem to the standard device driver
  12binding model, it became clear that these per-module parameters were no
  13longer needed, and that a centralized implementation was possible. The new,
  14sysfs-based interface is described in the documentation file
  15"instantiating-devices", section "Method 4: Instantiate from user-space".
  16
  17Below is a mapping from the old module parameters to the new interface.
  18
  19Attaching a driver to an I2C device
  20-----------------------------------
  21
  22Old method (module parameters):
  23# modprobe <driver> probe=1,0x2d
  24# modprobe <driver> force=1,0x2d
  25# modprobe <driver> force_<device>=1,0x2d
  26
  27New method (sysfs interface):
  28# echo <device> 0x2d > /sys/bus/i2c/devices/i2c-1/new_device
  29
  30Preventing a driver from attaching to an I2C device
  31---------------------------------------------------
  32
  33Old method (module parameters):
  34# modprobe <driver> ignore=1,0x2f
  35
  36New method (sysfs interface):
  37# echo dummy 0x2f > /sys/bus/i2c/devices/i2c-1/new_device
  38# modprobe <driver>
  39
  40Of course, it is important to instantiate the "dummy" device before loading
  41the driver. The dummy device will be handled by i2c-core itself, preventing
  42other drivers from binding to it later on. If there is a real device at the
  43problematic address, and you want another driver to bind to it, then simply
  44pass the name of the device in question instead of "dummy".
  45
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