On 2020-03-06 10:54, Andy Shevchenko wrote:
> On Thu, Mar 05, 2020 at 09:05:56PM +0000, Peter Rosin wrote:
>> On 2020-03-05 16:53, Andy Shevchenko wrote:
>>> Device property API allows to gather device resources from different sources,
>>> such as ACPI. Convert the drivers to unleash the power of device property API.
>
> ...
>
>>> static const struct i2c_device_id pca954x_id[] = {
>>> - { "pca9540", pca_9540 },
>>> - { "pca9542", pca_9542 },
>>> - { "pca9543", pca_9543 },
>>> - { "pca9544", pca_9544 },
>>> - { "pca9545", pca_9545 },
>>> - { "pca9546", pca_9546 },
>>> - { "pca9547", pca_9547 },
>>> - { "pca9548", pca_9548 },
>>> - { "pca9846", pca_9846 },
>>> - { "pca9847", pca_9847 },
>>> - { "pca9848", pca_9848 },
>>> - { "pca9849", pca_9849 },
>>> + { "pca9540", .driver_data = (kernel_ulong_t)&chips[pca_9540] },
>>> + { "pca9542", .driver_data = (kernel_ulong_t)&chips[pca_9542] },
>>> + { "pca9543", .driver_data = (kernel_ulong_t)&chips[pca_9543] },
>>> + { "pca9544", .driver_data = (kernel_ulong_t)&chips[pca_9544] },
>>> + { "pca9545", .driver_data = (kernel_ulong_t)&chips[pca_9545] },
>>> + { "pca9546", .driver_data = (kernel_ulong_t)&chips[pca_9546] },
>>> + { "pca9547", .driver_data = (kernel_ulong_t)&chips[pca_9547] },
>>> + { "pca9548", .driver_data = (kernel_ulong_t)&chips[pca_9548] },
>>> + { "pca9846", .driver_data = (kernel_ulong_t)&chips[pca_9846] },
>>> + { "pca9847", .driver_data = (kernel_ulong_t)&chips[pca_9847] },
>>> + { "pca9848", .driver_data = (kernel_ulong_t)&chips[pca_9848] },
>>> + { "pca9849", .driver_data = (kernel_ulong_t)&chips[pca_9849] },
>>
>> It feels odd/wrong to specifically name .driver_data when .name is not there.
>> None or both...
>
> I will add .name as well.
>
>>> + data->chip = device_get_match_data(dev);
>>> if (!data->chip)
>>> data->chip = &chips[id->driver_data];
>>
>> These two lines no longer make any sence.
>
> Please elaborate.
>
> IIRC Javier explained once that I²C ID table is still good to have to allow
> enumeration from user space.
id->driver_data is no longer an integer index into chips[]. So, for the I2C
ID table case, either device_get_match_data returns the .driver_data as-is
from the pca954x_id array, or it returns NULL (I don't know which it is).
In the first case, if (!data->chip) ...; is useless dead code. In the latter
case, it should be
if (!data->chip)
data->chip = (whatever-type-chip-is *)id->driver_data;
(If it's this latter case, I get the feeling that changing the .driver_data
of pca954x_id is an orthogonal change that has little to do with using
device properties instead of of-specifics.)
Cheers,
Peter
