On Mon, 01 Sep 2014, Vignesh R wrote:
> After enabling and disabling ADC continuous mode via sysfs, ts_print_raw
> fails to return any data. This is because when ADC is configured for
> continuous mode, it disables touch screen steps.These steps are not
> re-enabled when ADC continuous mode is disabled. Therefore existing values
> of REG_SE needs to be cached before enabling continuous mode and
> disabling touch screen steps and enabling ADC steps. The cached value
> are to be restored to REG_SE once ADC is disabled.
>
> Fixes: 7ca6740cd1cd ("mfd: input: iio: ti_amm335x: Rework TSC/ADC synchronization")
>
> Cc: stable@xxxxxxxxxxxxxxx # v3.13+
> Acked-by: Lee Jones <lee.jones@xxxxxxxxxx>
> Signed-off-by: Vignesh R <vigneshr@xxxxxx>
> ---
> fixed $SUBJECT, added stable and ack from Lee Jones.
> No code change.
>
> drivers/mfd/ti_am335x_tscadc.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
Applied, thanks.
> diff --git a/drivers/mfd/ti_am335x_tscadc.c b/drivers/mfd/ti_am335x_tscadc.c
> index d4e860413bb5..e3076afe6b3c 100644
> --- a/drivers/mfd/ti_am335x_tscadc.c
> +++ b/drivers/mfd/ti_am335x_tscadc.c
> @@ -54,7 +54,7 @@ void am335x_tsc_se_set_cache(struct ti_tscadc_dev *tsadc, u32 val)
> unsigned long flags;
>
> spin_lock_irqsave(&tsadc->reg_lock, flags);
> - tsadc->reg_se_cache = val;
> + tsadc->reg_se_cache |= val;
> if (tsadc->adc_waiting)
> wake_up(&tsadc->reg_se_wait);
> else if (!tsadc->adc_in_use)
> @@ -97,6 +97,7 @@ static void am335x_tscadc_need_adc(struct ti_tscadc_dev *tsadc)
> void am335x_tsc_se_set_once(struct ti_tscadc_dev *tsadc, u32 val)
> {
> spin_lock_irq(&tsadc->reg_lock);
> + tsadc->reg_se_cache |= val;
> am335x_tscadc_need_adc(tsadc);
>
> tscadc_writel(tsadc, REG_SE, val);
--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
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