[RESEND PATCH] iio: adc: at91: don't use the last converted data register

[Ludovic Desroches]

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 at atmel.com>
---

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