This is a note to let you know that I've just added the patch titled
iio: adc: at91: don't use the last converted data register
to the 3.16-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
iio-adc-at91-don-t-use-the-last-converted-data-register.patch
and it can be found in the queue-3.16 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From d4f51956ac8ad302db9b0c4e4232775b1baa7b44 Mon Sep 17 00:00:00 2001
From: Ludovic Desroches <ludovic.desroches@xxxxxxxxx>
Date: Thu, 9 Oct 2014 15:02:00 +0100
Subject: iio: adc: at91: don't use the last converted data register
From: Ludovic Desroches <ludovic.desroches@xxxxxxxxx>
commit d4f51956ac8ad302db9b0c4e4232775b1baa7b44 upstream.
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>
Acked-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxxxxxxxxx>
Acked-by: Nicolas Ferre <nicolas.ferre@xxxxxxxxx>
Signed-off-by: Jonathan Cameron <jic23@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/iio/adc/at91_adc.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)
--- 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, str
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);
}
@@ -351,7 +352,7 @@ static irqreturn_t at91_adc_rl_interrupt
unsigned int reg;
status &= at91_adc_readl(st, AT91_ADC_IMR);
- if (status & st->registers->drdy_mask)
+ if (status & GENMASK(st->num_channels - 1, 0))
handle_adc_eoc_trigger(irq, idev);
if (status & AT91RL_ADC_IER_PEN) {
@@ -418,7 +419,7 @@ static irqreturn_t at91_adc_9x5_interrup
AT91_ADC_IER_YRDY |
AT91_ADC_IER_PRDY;
- if (status & st->registers->drdy_mask)
+ if (status & GENMASK(st->num_channels - 1, 0))
handle_adc_eoc_trigger(irq, idev);
if (status & AT91_ADC_IER_PEN) {
@@ -689,9 +690,10 @@ static int at91_adc_read_raw(struct iio_
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, BIT(chan->channel));
at91_adc_writel(st, AT91_ADC_CR, AT91_ADC_START);
ret = wait_event_interruptible_timeout(st->wq_data_avail,
@@ -708,7 +710,7 @@ static int at91_adc_read_raw(struct iio_
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, BIT(chan->channel));
st->last_value = 0;
st->done = false;
Patches currently in stable-queue which might be from ludovic.desroches@xxxxxxxxx are
queue-3.16/i2c-at91-add-bound-checking-on-smbus-block-length-bytes.patch
queue-3.16/i2c-at91-fix-a-race-condition-during-signal-handling-in-at91_do_twi_xfer.patch
queue-3.16/iio-adc-at91-don-t-use-the-last-converted-data-register.patch
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