From 62184eb778213a807744d563b0df286dbdb98448 Mon Sep 17 00:00:00 2001 From: Robert Hancock Date: Thu, 14 Sep 2023 18:10:18 -0600 Subject: [PATCH] iio: adc: xilinx-xadc: Don't clobber preset voltage/temperature thresholds [ Upstream commit 8d6b3ea4d9eaca80982442b68a292ce50ce0a135 ] In the probe function, the driver was reading out the thresholds already set in the core, which can be configured by the user in the Vivado tools when the FPGA image is built. However, it later clobbered those values with zero or maximum values. In particular, the overtemperature shutdown threshold register was overwritten with the max value, which effectively prevents the FPGA from shutting down when the desired threshold was eached, potentially risking hardware damage in that case. Remove this code to leave the preconfigured default threshold values intact. The code was also disabling all alarms regardless of what enable state they were left in by the FPGA image, including the overtemperature shutdown feature. Leave these bits in their original state so they are not unconditionally disabled. Fixes: bdc8cda1d010 ("iio:adc: Add Xilinx XADC driver") Signed-off-by: Robert Hancock Acked-by: O'Griofa, Conall Tested-by: O'Griofa, Conall Link: https://lore.kernel.org/r/20230915001019.2862964-2-robert.hancock@calian.com Cc: Signed-off-by: Jonathan Cameron Signed-off-by: Sasha Levin --- drivers/iio/adc/xilinx-xadc-core.c | 22 ---------------------- 1 file changed, 22 deletions(-) diff --git a/drivers/iio/adc/xilinx-xadc-core.c b/drivers/iio/adc/xilinx-xadc-core.c index fec266682e91..30b5a17ce41a 100644 --- a/drivers/iio/adc/xilinx-xadc-core.c +++ b/drivers/iio/adc/xilinx-xadc-core.c @@ -1334,28 +1334,6 @@ static int xadc_probe(struct platform_device *pdev) if (ret) return ret; - /* Disable all alarms */ - ret = xadc_update_adc_reg(xadc, XADC_REG_CONF1, XADC_CONF1_ALARM_MASK, - XADC_CONF1_ALARM_MASK); - if (ret) - return ret; - - /* Set thresholds to min/max */ - for (i = 0; i < 16; i++) { - /* - * Set max voltage threshold and both temperature thresholds to - * 0xffff, min voltage threshold to 0. - */ - if (i % 8 < 4 || i == 7) - xadc->threshold[i] = 0xffff; - else - xadc->threshold[i] = 0; - ret = xadc_write_adc_reg(xadc, XADC_REG_THRESHOLD(i), - xadc->threshold[i]); - if (ret) - return ret; - } - /* Go to non-buffered mode */ xadc_postdisable(indio_dev);