[PATCH 6.8 277/336] iio: accel: mxc4005: Reset chip on probe() and resume()

Greg Kroah-Hartman
2024-05-14T10:54:26Z

From: Hans de Goede <hdegoede@redhat.com>

commit 6b8cffdc4a31e4a72f75ecd1bc13fbf0dafee390 upstream.

On some designs the chip is not properly reset when powered up at boot or
after a suspend/resume cycle.

Use the sw-reset feature to ensure that the chip is in a clean state
after probe() / resume() and in the case of resume() restore the settings
(scale, trigger-enabled).

Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218578
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20240326113700.56725-3-hdegoede@redhat.com
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/iio/accel/mxc4005.c | 68 ++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 68 insertions(+)

--- a/drivers/iio/accel/mxc4005.c
+++ b/drivers/iio/accel/mxc4005.c
@@ -5,6 +5,7 @@
* Copyright (c) 2014, Intel Corporation.
*/

+#include <linux/delay.h>
#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/iio/iio.h>
@@ -36,6 +37,7 @@

#define MXC4005_REG_INT_CLR1 0x01
#define MXC4005_REG_INT_CLR1_BIT_DRDYC 0x01
+#define MXC4005_REG_INT_CLR1_SW_RST 0x10

#define MXC4005_REG_CONTROL 0x0D
#define MXC4005_REG_CONTROL_MASK_FSR GENMASK(6, 5)
@@ -43,6 +45,9 @@

#define MXC4005_REG_DEVICE_ID 0x0E

+/* Datasheet does not specify a reset time, this is a conservative guess */
+#define MXC4005_RESET_TIME_US 2000
+
enum mxc4005_axis {
AXIS_X,
AXIS_Y,
@@ -66,6 +71,8 @@ struct mxc4005_data {
s64 timestamp __aligned(8);
} scan;
bool trigger_enabled;
+ unsigned int control;
+ unsigned int int_mask1;
};

/*
@@ -349,6 +356,7 @@ static int mxc4005_set_trigger_state(str
return ret;
}

+ data->int_mask1 = val;
data->trigger_enabled = state;
mutex_unlock(&data->mutex);

@@ -384,6 +392,13 @@ static int mxc4005_chip_init(struct mxc4

dev_dbg(data->dev, "MXC4005 chip id %02x\n", reg);

+ ret = regmap_write(data->regmap, MXC4005_REG_INT_CLR1,
+ MXC4005_REG_INT_CLR1_SW_RST);
+ if (ret < 0)
+ return dev_err_probe(data->dev, ret, "resetting chip\n");
+
+ fsleep(MXC4005_RESET_TIME_US);
+
ret = regmap_write(data->regmap, MXC4005_REG_INT_MASK0, 0);
if (ret < 0)
return dev_err_probe(data->dev, ret, "writing INT_MASK0\n");
@@ -479,6 +494,58 @@ static int mxc4005_probe(struct i2c_clie
return devm_iio_device_register(&client->dev, indio_dev);
}

+static int mxc4005_suspend(struct device *dev)
+{
+ struct iio_dev *indio_dev = dev_get_drvdata(dev);
+ struct mxc4005_data *data = iio_priv(indio_dev);
+ int ret;
+
+ /* Save control to restore it on resume */
+ ret = regmap_read(data->regmap, MXC4005_REG_CONTROL, &data->control);
+ if (ret < 0)
+ dev_err(data->dev, "failed to read reg_control\n");
+
+ return ret;
+}
+
+static int mxc4005_resume(struct device *dev)
+{
+ struct iio_dev *indio_dev = dev_get_drvdata(dev);
+ struct mxc4005_data *data = iio_priv(indio_dev);
+ int ret;
+
+ ret = regmap_write(data->regmap, MXC4005_REG_INT_CLR1,
+ MXC4005_REG_INT_CLR1_SW_RST);
+ if (ret) {
+ dev_err(data->dev, "failed to reset chip: %d\n", ret);
+ return ret;
+ }
+
+ fsleep(MXC4005_RESET_TIME_US);
+
+ ret = regmap_write(data->regmap, MXC4005_REG_CONTROL, data->control);
+ if (ret) {
+ dev_err(data->dev, "failed to restore control register\n");
+ return ret;
+ }
+
+ ret = regmap_write(data->regmap, MXC4005_REG_INT_MASK0, 0);
+ if (ret) {
+ dev_err(data->dev, "failed to restore interrupt 0 mask\n");
+ return ret;
+ }
+
+ ret = regmap_write(data->regmap, MXC4005_REG_INT_MASK1, data->int_mask1);
+ if (ret) {
+ dev_err(data->dev, "failed to restore interrupt 1 mask\n");
+ return ret;
+ }
+
+ return 0;
+}
+
+static DEFINE_SIMPLE_DEV_PM_OPS(mxc4005_pm_ops, mxc4005_suspend, mxc4005_resume);
+
static const struct acpi_device_id mxc4005_acpi_match[] = {
{"MXC4005", 0},
{"MXC6655", 0},
@@ -505,6 +572,7 @@ static struct i2c_driver mxc4005_driver
.name = MXC4005_DRV_NAME,
.acpi_match_table = ACPI_PTR(mxc4005_acpi_match),
.of_match_table = mxc4005_of_match,
+ .pm = pm_sleep_ptr(&mxc4005_pm_ops),
},
.probe = mxc4005_probe,
.id_table = mxc4005_id,