On Mon, Jan 13, 2014 at 1:29 PM, Mark Brown <[email protected]> wrote:
>> +static int rspi_parse_platform_data(struct rspi_data *rspi,
>> + const struct rspi_plat_data *rspi_pd)
>> +{
>> + if (rspi_pd && rspi_pd->data_width) {
>> + rspi->data_width = rspi_pd->data_width;
>> + switch (rspi_pd->data_width) {
>> + case 8:
>> + rspi->spdcr = SPDCR_SPLBYTE;
>> + break;
>> + case 16:
>> + rspi->spdcr = SPDCR_SPLWORD;
>> + break;
>> + default:
>> + return -EINVAL;
>> + }
>> + } else {
>> + /*
>> + * Use legacy 16-bit width data access if a data_width value
>> + * isn't defined in the platform data.
>> + */
>> + rspi->data_width = 16;
>> + rspi->spdcr = 0;
>> + }
>
> This looks very strange - if no platform data is specified the value set
> for spdcr is one that can't be arrived at via platform data. What's
> going on here? It'd seem more idiomatic to treat missing platform data
> and a zero data_width identically too.
The else branch is also taken when platform data is specified, but
data_width is zero. So you can indicate legacy 16-bit data width through
platform data.
It's unfortunate that the bits inside spdcr to configure the data width are
different for RSPI on SH and RSPI on ARM.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected]
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
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