Hello Guenter,
[dropped Jose Ramon San Buenaventura from Cc: who's address bounced]
On Thu, Dec 05, 2024 at 08:27:15AM -0800, Guenter Roeck wrote:
> On Thu, Dec 05, 2024 at 04:28:33PM +0100, Uwe Kleine-König wrote:
> > I intend to change the definition of struct i2c_device_id to look as
> > follows:
> >
> > struct i2c_device_id {
> > char name[I2C_NAME_SIZE];
> > /* Data private to the driver */
> > union {
> > kernel_ulong_t driver_data;
> > const void *driver_data_ptr;
> > };
> > };
> >
> > That the initializers for these structures also work with this new
> > definition, they must use named members.
> >
> > The motivation for that change is to be able to drop many casts from
> > pointer to kernel_ulong_t. So once the definition is updated,
> > initializers that today use:
> >
> > {"adp4000", (kernel_ulong_t)&pmbus_info_one},
> >
> > can be changed to
> >
> > { .name = "adp4000", .driver_data_ptr = &pmbus_info_one },
> >
>
> How about introducing a macro for that instead, similar to I3C_DEVICE() ?
OK, for now we'd have then:
#define I2C_DEVICE_ID_PTR(_name, _driver_data_ptr) \
{ .name = (_name), .driver_data = (kernel_ulong_t)_driver_data_ptr }
#define I2C_DEVICE_ID_ULONG(_name, _driver_data) \
{ .name = (_name), .driver_data = _driver_data }
plus maybe:
#define I2C_DEVICE_ID(_name) \
{ .name = (_name) }
for the drivers that don't need driver data?
And usage would look as follows:
static const struct i2c_device_id pmbus_id[] = {
I2C_DEVICE_ID_PTR("adp4000", &pmbus_info_one),
...
{ }
};
or for the ulong case:
static const struct i2c_device_id ads7828_device_ids[] = {
I2C_DEVICE_ID_ULONG("ads7828", ads7828),
I2C_DEVICE_ID_ULONG("ads7830", ads7830),
{ }
};
When all drivers are converted accordingly, we could change the
definition of i2c_device_id in a commit that only touches i2c core
things to introduce the stronger type checking.
One additional small but nice thing about that is that it could be
applied to the other *_device_ids, too and then the inconsistencies
between those (e.g. for dmi_system_id .driver_data is a void * and for
mei_cl_device_id the kernel_ulong_t member is called driver_info) could
be addressed without having to touch all drivers again.
I would be open for that. Wolfram?
Best regards
Uwe
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