The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
Possible dependencies:
57572cacd36e ("iio: accel: bma400: Ensure VDDIO is enable defore reading the chip ID.")
12c99f859fd3 ("iio: accel: bma400: conversion to device-managed function")
02e2af20f4f9 ("Merge tag 'char-misc-5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 57572cacd36e6d4be7722d7770d23f4430219827 Mon Sep 17 00:00:00 2001
From: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Date: Sun, 2 Oct 2022 15:41:33 +0100
Subject: [PATCH] iio: accel: bma400: Ensure VDDIO is enable defore reading the
chip ID.
The regulator enables were after the check on the chip variant, which was
very unlikely to return a correct value when not powered.
Presumably all the device anyone is testing on have a regulator that
is already powered up when this code runs for reasons beyond the scope
of this driver. Move the read call down a few lines.
Fixes: 3cf7ded15e40 ("iio: accel: bma400: basic regulator support")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Reviewed-by: Dan Robertson <dan@xxxxxxxxxxxxxxx>
Cc: <Stable@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20221002144133.3771029-1-jic23@xxxxxxxxxx
diff --git a/drivers/iio/accel/bma400_core.c b/drivers/iio/accel/bma400_core.c
index ad8fce3e08cd..490c342ef72a 100644
--- a/drivers/iio/accel/bma400_core.c
+++ b/drivers/iio/accel/bma400_core.c
@@ -869,18 +869,6 @@ static int bma400_init(struct bma400_data *data)
unsigned int val;
int ret;
- /* Try to read chip_id register. It must return 0x90. */
- ret = regmap_read(data->regmap, BMA400_CHIP_ID_REG, &val);
- if (ret) {
- dev_err(data->dev, "Failed to read chip id register\n");
- return ret;
- }
-
- if (val != BMA400_ID_REG_VAL) {
- dev_err(data->dev, "Chip ID mismatch\n");
- return -ENODEV;
- }
-
data->regulators[BMA400_VDD_REGULATOR].supply = "vdd";
data->regulators[BMA400_VDDIO_REGULATOR].supply = "vddio";
ret = devm_regulator_bulk_get(data->dev,
@@ -906,6 +894,18 @@ static int bma400_init(struct bma400_data *data)
if (ret)
return ret;
+ /* Try to read chip_id register. It must return 0x90. */
+ ret = regmap_read(data->regmap, BMA400_CHIP_ID_REG, &val);
+ if (ret) {
+ dev_err(data->dev, "Failed to read chip id register\n");
+ return ret;
+ }
+
+ if (val != BMA400_ID_REG_VAL) {
+ dev_err(data->dev, "Chip ID mismatch\n");
+ return -ENODEV;
+ }
+
ret = bma400_get_power_mode(data);
if (ret) {
dev_err(data->dev, "Failed to get the initial power-mode\n");
