diff options
author | Jean Delvare <khali@linux-fr.org> | 2008-07-14 20:38:36 (GMT) |
---|---|---|
committer | Jean Delvare <khali@mahadeva.delvare> | 2008-07-14 20:38:36 (GMT) |
commit | 4735c98f8447acb1c8977e2b8024640f7bf36dd6 (patch) | |
tree | 7f7c65b1feef6a0213caa20218cd6080488cc62b /drivers/i2c/busses | |
parent | 8508159e2f3b82bf109f0ec77bcbd8ff3f3a7e17 (diff) | |
download | linux-fsl-qoriq-4735c98f8447acb1c8977e2b8024640f7bf36dd6.tar.xz |
i2c: Add detection capability to new-style drivers
Add a mechanism to let new-style i2c drivers optionally autodetect
devices they would support on selected buses and ask i2c-core to
instantiate them. This is a replacement for legacy i2c drivers, much
cleaner.
Where drivers had to implement both a legacy i2c_driver and a
new-style i2c_driver so far, this mechanism makes it possible to get
rid of the legacy i2c_driver and implement both enumerated and
detected device support with just one (new-style) i2c_driver.
Here is a quick conversion guide for these drivers, step by step:
* Delete the legacy driver definition, registration and removal.
Delete the attach_adapter and detach_client methods of the legacy
driver.
* Change the prototype of the legacy detect function from
static int foo_detect(struct i2c_adapter *adapter, int address, int kind);
to
static int foo_detect(struct i2c_client *client, int kind,
struct i2c_board_info *info);
* Set the new-style driver detect callback to this new function, and
set its address_data to &addr_data (addr_data is generally provided
by I2C_CLIENT_INSMOD.)
* Add the appropriate class to the new-style driver. This is
typically the class the legacy attach_adapter method was checking
for. Class checking is now mandatory (done by i2c-core.) See
<linux/i2c.h> for the list of available classes.
* Remove the i2c_client allocation and freeing from the detect
function. A pre-allocated client is now handed to you by i2c-core,
and is freed automatically.
* Make the detect function fill the type field of the i2c_board_info
structure it was passed as a parameter, and return 0, on success. If
the detection fails, return -ENODEV.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Diffstat (limited to 'drivers/i2c/busses')
0 files changed, 0 insertions, 0 deletions