[PATCH] largefile support for accounting

[linux-2.6] / Documentation / i2c / writing-clients

diff --git a/Documentation/i2c/writing-clients b/Documentation/i2c/writing-clients
index 43d7928056ae0b5b08435daa8f0204c521086def..077275722a7ccce46cfb1c12e04ed3abe688bd1b 100644 (file)
--- a/Documentation/i2c/writing-clients
+++ b/Documentation/i2c/writing-clients
@@ -155,8 +155,8 @@ NOTE: If you want to write a `sensors' driver, the interface is slightly
 
 
 
-Probing classes (i2c)
----------------------
+Probing classes
+---------------
 
 All parameters are given as lists of unsigned 16-bit integers. Lists are
 terminated by I2C_CLIENT_END.
@@ -171,12 +171,18 @@ The following lists are used internally:
    ignore: insmod parameter.
      A list of pairs. The first value is a bus number (-1 for any I2C bus), 
      the second is the I2C address. These addresses are never probed. 
-     This parameter overrules 'normal' and 'probe', but not the 'force' lists.
+     This parameter overrules the 'normal_i2c' list only.
    force: insmod parameter. 
      A list of pairs. The first value is a bus number (-1 for any I2C bus),
      the second is the I2C address. A device is blindly assumed to be on
      the given address, no probing is done. 
 
+Additionally, kind-specific force lists may optionally be defined if
+the driver supports several chip kinds. They are grouped in a
+NULL-terminated list of pointers named forces, those first element if the
+generic force list mentioned above. Each additional list correspond to an
+insmod parameter of the form force_<kind>.
+
 Fortunately, as a module writer, you just have to define the `normal_i2c' 
 parameter. The complete declaration could look like this:
 
@@ -186,61 +192,17 @@ parameter. The complete declaration could look like this:
 
   /* Magic definition of all other variables and things */
   I2C_CLIENT_INSMOD;
+  /* Or, if your driver supports, say, 2 kind of devices: */
+  I2C_CLIENT_INSMOD_2(foo, bar);
+
+If you use the multi-kind form, an enum will be defined for you:
+  enum chips { any_chip, foo, bar, ... }
+You can then (and certainly should) use it in the driver code.
 
 Note that you *have* to call the defined variable `normal_i2c',
 without any prefix!
 
 
-Probing classes (sensors)
--------------------------
-
-If you write a `sensors' driver, you use a slightly different interface.
-Also, we use a enum of chip types. Don't forget to include `sensors.h'.
-
-The following lists are used internally. They are all lists of integers.
-
-   normal_i2c: filled in by the module writer. Terminated by I2C_CLIENT_END.
-     A list of I2C addresses which should normally be examined.
-   probe: insmod parameter. Initialize this list with I2C_CLIENT_END values.
-     A list of pairs. The first value is a bus number (ANY_I2C_BUS for any
-     I2C bus), the second is the address. These addresses are also probed,
-     as if they were in the 'normal' list.
-   ignore: insmod parameter. Initialize this list with I2C_CLIENT_END values.
-     A list of pairs. The first value is a bus number (ANY_I2C_BUS for any
-     I2C bus), the second is the I2C address. These addresses are never
-     probed. This parameter overrules 'normal' and 'probe', but not the
-     'force' lists.
-
-Also used is a list of pointers to sensors_force_data structures:
-   force_data: insmod parameters. A list, ending with an element of which
-     the force field is NULL.
-     Each element contains the type of chip and a list of pairs.
-     The first value is a bus number (ANY_I2C_BUS for any I2C bus), the
-     second is the address.
-     These are automatically translated to insmod variables of the form
-     force_foo.
-
-So we have a generic insmod variabled `force', and chip-specific variables
-`force_CHIPNAME'.
-
-Fortunately, as a module writer, you just have to define the `normal_i2c' 
-parameter, and define what chip names are used. The complete declaration
-could look like this:
-  /* Scan i2c addresses 0x37, and 0x48 to 0x4f */
-  static unsigned short normal_i2c[] = { 0x37, 0x48, 0x49, 0x4a, 0x4b, 0x4c,
-                                         0x4d, 0x4e, 0x4f, I2C_CLIENT_END };
-
-  /* Define chips foo and bar, as well as all module parameters and things */
-  SENSORS_INSMOD_2(foo,bar);
-
-If you have one chip, you use macro SENSORS_INSMOD_1(chip), if you have 2
-you use macro SENSORS_INSMOD_2(chip1,chip2), etc. If you do not want to
-bother with chip types, you can use SENSORS_INSMOD_0.
-
-A enum is automatically defined as follows:
-  enum chips { any_chip, chip1, chip2, ... }
-
-
 Attaching to an adapter
 -----------------------
 
@@ -279,9 +241,10 @@ Below, some things are only needed if this is a `sensors' driver. Those
 parts are between /* SENSORS ONLY START */ and /* SENSORS ONLY END */
 markers. 
 
-This function should only return an error (any value != 0) if there is
-some reason why no more detection should be done anymore. If the
-detection just fails for this address, return 0.
+Returning an error different from -ENODEV in a detect function will cause
+the detection to stop: other addresses and adapters won't be scanned.
+This should only be done on fatal or internal errors, such as a memory
+shortage or i2c_attach_client failing.
 
 For now, you can ignore the `flags' parameter. It is there for future use.