2017-12-05 0:13 GMT+09:00 Wolfram Sang <wsa@xxxxxxxxxxxxx>:
>> +static int tmio_mmc_get_cd(struct mmc_host *mmc)
>> +{
>> + struct tmio_mmc_host *host = mmc_priv(mmc);
>> + int ret;
>> +
>> + ret = mmc_gpio_get_cd(mmc);
>> + if (ret >= 0)
>> + return ret;
>> +
>> + return !!(sd_ctrl_read16_and_16_as_32(host, CTL_STATUS) &
>> + TMIO_STAT_SIGSTATE);
>> +}
I just followed tmio_mmc_get_ro() implementation.
If we do not care the symmetry between _get_ro() and _get_cd() hooks,
yes, your suggestion makes sense.
> I wonder if we shouldn't do something like:
>
> if (mmc_can_gpio_cd())
> return mmc_gpio_get_cd()
> else
> return !!(sd_ctrl_read16_and_16_as_32...)
>
> If we have a GPIO CD defined, I think we want the value of
> mmc_gpio_get_cd() in all cases. It makes clearer that this is an
> 'either-or' case and not a fallback mechanism.
>
Another possibility would select this in _probe().
We would need to evaluate mmc_can_gpio_cd() only once when probing.
I will follow your suggestion, though.
Either way is fine with me.
static int tmio_mmc_get_cd(struct mmc_host *mmc)
{
struct tmio_mmc_host *host = mmc_priv(mmc);
return !!(sd_ctrl_read16_and_16_as_32(host, CTL_STATUS) &
TMIO_STAT_SIGSTATE);
}
static const struct mmc_host_ops tmio_mmc_ops = {
...
.get_cd = tmio_mmc_get_cd,
...
};
int tmio_mmc_host_probe( ... )
{
....
/* replace get_cd hook when we use GPIO for card detection */
if (mmc_can_gpio_cd(mmc))
_host->ops.get_cd = mmc_gpio_get_cd;
}
--
Best Regards
Masahiro Yamada
