Subject: patch "iio: adc: nxp-sar-adc: Fix the delay calculation in" added to char-misc-linus
To: andriy.shevchenko@linux.intel.com,Stable@vger.kernel.org,daniel.lezcano@oss.qualcomm.com,jic23@kernel.org,sashiko-bot@kernel.org,sozdayvek@gmail.com
From: <gregkh@linuxfoundation.org>
Date: Thu, 09 Jul 2026 07:44:52 +0200
Message-ID: <2026070952-campsite-diffusive-0ba9@gregkh>
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This is a note to let you know that I've just added the patch titled

    iio: adc: nxp-sar-adc: Fix the delay calculation in

to my char-misc git tree which can be found at
    git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git
in the char-misc-linus branch.

The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)

The patch will hopefully also be merged in Linus's tree for the
next -rc kernel release.

If you have any questions about this process, please let me know.


From a9f41809bf1bd8e5c1bc4b6a1052adac58eb7ab6 Mon Sep 17 00:00:00 2001
From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Date: Tue, 19 May 2026 23:56:06 +0200
Subject: iio: adc: nxp-sar-adc: Fix the delay calculation in
 nxp_sar_adc_wait_for()

The original code was using ndelay() twice. In one case the delay
is calculated as 1/3 of ADC clock and in the other as 80 ADC clocks.
But according to the comments in all cases it should be a multiplier
of the ADC clock, and not a fraction of it. Inadvertently
nxp_sar_adc_wait_for() takes the wrong case and spread it over
the code make it wrong in all places. Fix this by modifying a helper
to correctly use the multiplier.

Fixes: 7e5c0f97c66a ("iio: adc: nxp-sar-adc: Avoid division by zero")
Fixes: 4434072a893e ("iio: adc: Add the NXP SAR ADC support for the s32g2/3 platforms")
Reported-by: Sashiko <sashiko-bot@kernel.org>
Closes: https://sashiko.dev/#/patchset/20260416090122.758990-1-andriy.shevchenko%40linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Stepan Ionichev <sozdayvek@gmail.com>
Acked-by: Daniel Lezcano <daniel.lezcano@oss.qualcomm.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
---
 drivers/iio/adc/nxp-sar-adc.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/adc/nxp-sar-adc.c b/drivers/iio/adc/nxp-sar-adc.c
index 15c7432808f4..6bf896915788 100644
--- a/drivers/iio/adc/nxp-sar-adc.c
+++ b/drivers/iio/adc/nxp-sar-adc.c
@@ -198,13 +198,13 @@ static void nxp_sar_adc_irq_cfg(struct nxp_sar_adc *info, bool enable)
 		writel(0, NXP_SAR_ADC_IMR(info->regs));
 }
 
-static void nxp_sar_adc_wait_for(struct nxp_sar_adc *info, unsigned int cycles)
+static void nxp_sar_adc_wait_for(struct nxp_sar_adc *info, u64 cycles)
 {
 	u64 rate;
 
 	rate = clk_get_rate(info->clk);
 	if (rate)
-		ndelay(div64_u64(NSEC_PER_SEC, rate * cycles));
+		ndelay(div64_u64(NSEC_PER_SEC * cycles, rate));
 }
 
 static bool nxp_sar_adc_set_enabled(struct nxp_sar_adc *info, bool enable)
-- 
2.55.0