On 03/09/2014 at 08:34:29 +0200, Ludovic Desroches wrote :
> If touchscreen mode is enabled and a conversion is requested on another
> channel, the result in the last converted data register can be a
> touchscreen relative value. Starting a conversion involves to do a
> conversion for all active channel. It starts with ADC channels and ends
> with touchscreen channels. Then if ADC_LCD register is not read quickly,
> its content may be a touchscreen conversion.
> To remove this temporal constraint, the conversion value is taken from
> the channel data register.
>
> Signed-off-by: Ludovic Desroches <ludovic.desroches@xxxxxxxxx>
I wondering whether we should get rid of drdy in the trigger path too.
Maybe this can be done in a follow-up patch. Else,
Acked-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxxxxxxxxx>
> ---
>
> Sorry for the noise, there was a typo in the CC list.
>
> drivers/iio/adc/at91_adc.c | 14 +++++++++-----
> 1 file changed, 9 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/iio/adc/at91_adc.c b/drivers/iio/adc/at91_adc.c
> index 3b5bacd..dde22cb 100644
> --- a/drivers/iio/adc/at91_adc.c
> +++ b/drivers/iio/adc/at91_adc.c
> @@ -196,6 +196,7 @@ struct at91_adc_state {
> bool done;
> int irq;
> u16 last_value;
> + int chnb;
> struct mutex lock;
> u8 num_channels;
> void __iomem *reg_base;
> @@ -274,7 +275,7 @@ void handle_adc_eoc_trigger(int irq, struct iio_dev *idev)
> disable_irq_nosync(irq);
> iio_trigger_poll(idev->trig, iio_get_time_ns());
> } else {
> - st->last_value = at91_adc_readl(st, AT91_ADC_LCDR);
> + st->last_value = at91_adc_readl(st, AT91_ADC_CHAN(st, st->chnb));
> st->done = true;
> wake_up_interruptible(&st->wq_data_avail);
> }
> @@ -348,10 +349,11 @@ static irqreturn_t at91_adc_rl_interrupt(int irq, void *private)
> struct iio_dev *idev = private;
> struct at91_adc_state *st = iio_priv(idev);
> u32 status = at91_adc_readl(st, st->registers->status_register);
> + const u32 eoc_mask = (1 << st->num_channels) - 1;
> unsigned int reg;
>
> status &= at91_adc_readl(st, AT91_ADC_IMR);
> - if (status & st->registers->drdy_mask)
> + if (status & eoc_mask)
> handle_adc_eoc_trigger(irq, idev);
>
> if (status & AT91RL_ADC_IER_PEN) {
> @@ -413,12 +415,13 @@ static irqreturn_t at91_adc_9x5_interrupt(int irq, void *private)
> struct iio_dev *idev = private;
> struct at91_adc_state *st = iio_priv(idev);
> u32 status = at91_adc_readl(st, st->registers->status_register);
> + const u32 eoc_mask = (1 << st->num_channels) - 1;
> const uint32_t ts_data_irq_mask =
> AT91_ADC_IER_XRDY |
> AT91_ADC_IER_YRDY |
> AT91_ADC_IER_PRDY;
>
> - if (status & st->registers->drdy_mask)
> + if (status & eoc_mask)
> handle_adc_eoc_trigger(irq, idev);
>
> if (status & AT91_ADC_IER_PEN) {
> @@ -689,9 +692,10 @@ static int at91_adc_read_raw(struct iio_dev *idev,
> case IIO_CHAN_INFO_RAW:
> mutex_lock(&st->lock);
>
> + st->chnb = chan->channel;
> at91_adc_writel(st, AT91_ADC_CHER,
> AT91_ADC_CH(chan->channel));
> - at91_adc_writel(st, AT91_ADC_IER, st->registers->drdy_mask);
> + at91_adc_writel(st, AT91_ADC_IER, 1 << chan->channel);
> at91_adc_writel(st, AT91_ADC_CR, AT91_ADC_START);
>
> ret = wait_event_interruptible_timeout(st->wq_data_avail,
> @@ -708,7 +712,7 @@ static int at91_adc_read_raw(struct iio_dev *idev,
>
> at91_adc_writel(st, AT91_ADC_CHDR,
> AT91_ADC_CH(chan->channel));
> - at91_adc_writel(st, AT91_ADC_IDR, st->registers->drdy_mask);
> + at91_adc_writel(st, AT91_ADC_IDR, 1 << chan->channel);
>
> st->last_value = 0;
> st->done = false;
> --
> 1.7.9.5
>
--
Alexandre Belloni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
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