Re: [PATCH] mfd: mc13xxx: Add mc34708 adc support

[Joe Perches]

On Wed, 2018-04-11 at 16:09 +0200, Lukasz Majewski wrote:
> From: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
> 
> The mc34708 has an improved adc. The older variants will always convert
> a fixed order of channels. The mc34708 can do up to eight conversions
> in arbitrary channel order. Currently this extended feature is not
> supported. We only support touchscreen conversions now, which will
> be sampled in a data format compatible to the older chips in order
> to keep the API between the mfd and the touchscreen driver.
[]
> diff --git a/drivers/mfd/mc13xxx-core.c b/drivers/mfd/mc13xxx-core.c
[]
> +static int mc34708_adc_conversion(struct mc13xxx *mc13xxx, unsigned int mode,
> +		unsigned int channel, u8 ato, bool atox,
> +		unsigned int *sample)
> +{
> +	int ret, i;
[]
> +	if (mc13xxx->adcflags & MC13XXX_ADC_WORKING) {
> +		ret = -EBUSY;
> +		goto out;
> +	}

This doesn't work.

> []
> +	mc13xxx_irq_free(mc13xxx, MC34708_IRQ_TSDONE, &adcdone_data);
> +
> +	if (!ret) {
> +		ret = -ETIMEDOUT;
> +		goto out;
> +	}
[]
> +out:
> +	ret = mc13xxx_reg_write(mc13xxx, MC13XXX_ADC0, old_adc0);

ret is reassigned here, so the ret = -<FOO>
uses above don't do what is expected.

> +
> +	mc13xxx->adcflags &= ~MC13XXX_ADC_WORKING;
> +	mc13xxx_unlock(mc13xxx);
> +
> +	return ret;
> +}