On Mon, Jun 1, 2020 at 12:19 PM Vadim Pasternak <[email protected]> wrote:
>
> Add support for attributes composed from few registers.
> Such attributes could occupy from 2 to 4 sequential registers.
> For word size register space complex attribute can occupy up to two
attributes
> register, for byte size - up to four. These attributes can carry, for
registers
> example, CPLD or FPGA versioning, power consuming info, etcetera.
> Such registers contain read only data.
read-only.
...
> + * There are four kinds of attributes: single bit, full register's
> + * bits, bit sequence, bits in few registers For the first kind field
> + * mask indicates which bits are not related and field bit is set
> zero.
> + * For the second kind field mask is set to zero and field bit is set
> + * with all bits one. No special handling for such kind of attributes
> -
> + * pass value as is. For the third kind, field mask indicates which
the field
> + * bits are related and field bit is set to the first bit number (from
the field
> + * 1 to 32) is the bit sequence. For the fourth kind - the number of
> + * registers which should be read for getting an attribute are
> specified
> + * through 'data->regnum' field.
> */
...
> + /*
> + * Some attributes could occupied few registers in case regmap
> + * bit size is 8 or 16. Compose such attribute from 'regnum'
attributes
> + * registers. Such attributes contain read only data.
read-only
> + */
> + if (data->regnum > 1 && !rw_flag)
This I didn't get. They contain read-only data and here you explicitly
turn down rw_flag == false.
Can you clarify this?
> + return -EINVAL;
> + for (i = 1; i < data->regnum; i++) {
> + ret = regmap_read(regmap, data->reg + i, &val);
> + if (ret)
> + goto access_error;
> +
> + *regval |= rol32(val, regsize * i);
> + }
--
With Best Regards,
Andy Shevchenko
