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From: Miquel Raynal <miquel.raynal@bootlin.com>
To: "Sa, Nuno" <Nuno.Sa@analog.com>
Cc: Jonathan Cameron <jic23@kernel.org>,
	Lars-Peter Clausen <lars@metafoo.de>,
	Thomas Petazzoni <thomas.petazzoni@bootlin.com>,
	"linux-iio@vger.kernel.org" <linux-iio@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 12/16] iio: adc: max1027: Introduce an end of conversion helper
Date: Thu, 2 Sep 2021 11:26:19 +0200	[thread overview]
Message-ID: <20210902112619.248bca16@xps13> (raw)
In-Reply-To: <SJ0PR03MB635976F76F5121FFF26E858B99C19@SJ0PR03MB6359.namprd03.prod.outlook.com>

Hi Nuno,

"Sa, Nuno" <Nuno.Sa@analog.com> wrote on Fri, 20 Aug 2021 07:28:17
+0000:

> > -----Original Message-----
> > From: Miquel Raynal <miquel.raynal@bootlin.com>
> > Sent: Wednesday, August 18, 2021 1:12 PM
> > To: Jonathan Cameron <jic23@kernel.org>; Lars-Peter Clausen
> > <lars@metafoo.de>
> > Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>; linux-
> > iio@vger.kernel.org; linux-kernel@vger.kernel.org; Miquel Raynal
> > <miquel.raynal@bootlin.com>
> > Subject: [PATCH 12/16] iio: adc: max1027: Introduce an end of
> > conversion helper
> > 
> > [External]
> > 
> > For now this helper only waits for the maximum duration of a
> > conversion,
> > but it will soon be improved to properly handle the end of conversion
> > interrupt.
> > 
> > Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
> > ---
> >  drivers/iio/adc/max1027.c | 23 +++++++++++++++++++++--
> >  1 file changed, 21 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/iio/adc/max1027.c b/drivers/iio/adc/max1027.c
> > index afc3ce69f7ea..2d6485591761 100644
> > --- a/drivers/iio/adc/max1027.c
> > +++ b/drivers/iio/adc/max1027.c
> > @@ -60,6 +60,9 @@
> >  #define MAX1027_NAVG_32   (0x03 << 2)
> >  #define MAX1027_AVG_EN    BIT(4)
> > 
> > +/* Device can achieve 300ksps so we assume a 3.33us conversion
> > delay */
> > +#define MAX1027_CONVERSION_UDELAY 4
> > +
> >  enum max1027_id {
> >  	max1027,
> >  	max1029,
> > @@ -236,6 +239,20 @@ struct max1027_state {
> >  	u8				reg ____cacheline_aligned;
> >  };
> > 
> > +static DECLARE_WAIT_QUEUE_HEAD(max1027_queue);
> > +
> > +static int max1027_wait_eoc(struct iio_dev *indio_dev)
> > +{
> > +	unsigned int conversion_time =
> > MAX1027_CONVERSION_UDELAY;
> > +
> > +	if (indio_dev->active_scan_mask)
> > +		conversion_time *= hweight32(*indio_dev-  
> > >active_scan_mask);  
> > +
> > +	usleep_range(conversion_time, conversion_time * 2);
> > +
> > +	return 0;
> > +}
> > +
> >  /* Scan from 0 to the highest requested channel */
> >  static int max1027_configure_chans_to_scan(struct iio_dev
> > *indio_dev)
> >  {
> > @@ -310,9 +327,11 @@ static int max1027_read_single_value(struct
> > iio_dev *indio_dev,
> >  	/*
> >  	 * For an unknown reason, when we use the mode "10" (write
> >  	 * conversion register), the interrupt doesn't occur every time.
> > -	 * So we just wait 1 ms.
> > +	 * So we just wait the maximum conversion time and deliver
> > the value.
> >  	 */
> > -	mdelay(1);
> > +	ret = max1027_wait_eoc(indio_dev);
> > +	if (ret)
> > +		return ret;  
> 
> I'm a bit confused here... Why are we looking at the active_scan_mask?
> Aren't we preventing this for running concurrently with buffering?

Sorry for the confusion, at this stage the "if (active_masks)" is
useless, I moved it later in the series when we actually start to use
this EOC helper for the buffered reads as well.

Thanks,
Miquèl

  reply	other threads:[~2021-09-02  9:26 UTC|newest]

Thread overview: 71+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-18 11:11 [PATCH 00/16] Bring software triggers support to MAX1027-like ADCs Miquel Raynal
2021-08-18 11:11 ` [PATCH 01/16] iio: adc: max1027: Fix wrong shift with 12-bit devices Miquel Raynal
2021-08-20  7:02   ` Sa, Nuno
2021-08-30  9:57     ` Jonathan Cameron
2021-08-18 11:11 ` [PATCH 02/16] iio: adc: max1027: Fix the number of max1X31 channels Miquel Raynal
2021-08-20  7:03   ` Sa, Nuno
2021-08-30 10:00     ` Jonathan Cameron
2021-08-18 11:11 ` [PATCH 03/16] iio: adc: max1027: Push only the requested samples Miquel Raynal
2021-08-20  7:10   ` Sa, Nuno
2021-08-30 10:07     ` Jonathan Cameron
2021-08-30 10:49       ` Sa, Nuno
2021-08-30 14:29         ` Jonathan Cameron
2021-08-30 15:02           ` Sa, Nuno
2021-09-01  8:12             ` Miquel Raynal
2021-09-04 14:06               ` Jonathan Cameron
2021-09-06  8:59               ` Sa, Nuno
2021-09-06 16:56                 ` Jonathan Cameron
2021-09-06 17:34                   ` Miquel Raynal
2021-08-30 10:06   ` Jonathan Cameron
2021-08-18 11:11 ` [PATCH 04/16] iio: adc: max1027: Lower conversion time Miquel Raynal
2021-08-20  7:12   ` Sa, Nuno
2021-08-30 10:10   ` Jonathan Cameron
2021-08-18 11:11 ` [PATCH 05/16] iio: adc: max1027: Drop extra warning message Miquel Raynal
2021-08-20  7:12   ` Sa, Nuno
2021-08-30 10:12   ` Jonathan Cameron
2021-08-18 11:11 ` [PATCH 06/16] iio: adc: max1027: Rename a helper Miquel Raynal
2021-08-20  7:13   ` Sa, Nuno
2021-08-18 11:11 ` [PATCH 07/16] iio: adc: max1027: Create a helper to configure the trigger Miquel Raynal
2021-08-20  7:16   ` Sa, Nuno
2021-08-30 10:16   ` Jonathan Cameron
2021-08-18 11:11 ` [PATCH 08/16] iio: adc: max1027: Explain better how the trigger state gets changed Miquel Raynal
2021-08-20  7:17   ` Sa, Nuno
2021-08-18 11:11 ` [PATCH 09/16] iio: adc: max1027: Create a helper to configure the channels to scan Miquel Raynal
2021-08-20  7:18   ` Sa, Nuno
2021-08-18 11:11 ` [PATCH 10/16] iio: adc: max1027: Prevent single channel accesses during buffer reads Miquel Raynal
2021-08-20  7:20   ` Sa, Nuno
2021-08-20  7:30     ` Sa, Nuno
2021-08-30 10:20       ` Jonathan Cameron
2021-09-02  8:56         ` Miquel Raynal
2021-08-18 11:11 ` [PATCH 11/16] iio: adc: max1027: Separate the IRQ handler from the read logic Miquel Raynal
2021-08-20  7:23   ` Sa, Nuno
2021-09-02  8:55     ` Miquel Raynal
2021-09-04 14:08       ` Jonathan Cameron
2021-08-18 11:11 ` [PATCH 12/16] iio: adc: max1027: Introduce an end of conversion helper Miquel Raynal
2021-08-20  7:28   ` Sa, Nuno
2021-09-02  9:26     ` Miquel Raynal [this message]
2021-08-30 10:34   ` Jonathan Cameron
2021-08-18 11:11 ` [PATCH 13/16] iio: adc: max1027: Prepare re-using the EOC interrupt Miquel Raynal
2021-08-20  7:31   ` Sa, Nuno
2021-08-30 10:30   ` Jonathan Cameron
2021-08-30 10:47   ` Jonathan Cameron
2021-08-18 11:11 ` [PATCH 14/16] iio: adc: max1027: Consolidate the end of conversion helper Miquel Raynal
2021-08-20  7:45   ` Sa, Nuno
2021-08-30 10:37   ` Jonathan Cameron
2021-08-30 12:44     ` Sa, Nuno
2021-08-30 14:32       ` Jonathan Cameron
2021-09-02 15:12       ` Miquel Raynal
2021-09-03 14:28         ` Sa, Nuno
2021-09-03 14:46           ` Miquel Raynal
2021-09-05  9:41             ` Jonathan Cameron
2021-09-06  9:12               ` Sa, Nuno
2021-09-06  9:30                 ` Sa, Nuno
2021-08-18 11:11 ` [PATCH 15/16] iio: adc: max1027: Support software triggers Miquel Raynal
2021-08-20  7:58   ` Sa, Nuno
2021-09-02 12:25     ` Miquel Raynal
2021-09-03 14:20       ` Sa, Nuno
2021-08-30 10:50   ` Jonathan Cameron
2021-09-02 15:21     ` Miquel Raynal
2021-09-05  9:43       ` Jonathan Cameron
2021-08-18 11:11 ` [PATCH 16/16] iio: adc: max1027: Enable software triggers to be used without IRQ Miquel Raynal
2021-08-30 10:54   ` Jonathan Cameron

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