OpenCloudOS-Kernel/drivers/iio/imu/inv_mpu6050/inv_mpu_i2c.c

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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2012 Invensense, Inc.
*/
#include <linux/acpi.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/iio/iio.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include "inv_mpu_iio.h"
static const struct regmap_config inv_mpu_regmap_config = {
.reg_bits = 8,
.val_bits = 8,
};
static int inv_mpu6050_select_bypass(struct i2c_mux_core *muxc, u32 chan_id)
{
iio: imu: inv_mpu6050: change the i2c gate to be mux-locked The root i2c adapter lock is then no longer held by the i2c mux during accesses behind the i2c gate, and such accesses need to take that lock just like any other ordinary i2c accesses do. So, declare the i2c gate mux-locked, and zap the code that makes the unlocked i2c accesses and just use ordinary regmap_write accesses. This also happens to fix the deadlock described in http://patchwork.ozlabs.org/patch/584776/ authored by Adriana Reus <adriana.reus@intel.com> and submitted by Daniel Baluta <daniel.baluta@intel.com> ----------8<---------- iio: imu: inv_mpu6050: Fix deadlock between i2c adapter lock and mpu lock This deadlock occurs if the accel/gyro and the sensor on the auxiliary I2C (in my setup it's an ak8975) are working at the same time. Scenario: T1 T2 ==== ==== inv_mpu6050_read_fifo aux sensor op (eg. ak8975_read_raw) | | mutex_lock(&indio_dev->mlock) i2c_transfer | | i2c transaction i2c adapter lock | | i2c adapter lock i2c_mux_master_xfer | inv_mpu6050_select_bypass | mutex_lock(&indio_dev->mlock) When we operate on an mpu sensor the order of locking is mpu lock followed by the i2c adapter lock. However, when we operate the auxiliary sensor the order of locking is the other way around. ... ----------8<---------- The reason this patch fixes the deadlock is that T2 does not grab the i2c adapter lock until the very end (and grabs the newfangled i2c mux lock where it previously grabbed the i2c adapter lock). Acked-by: Jonathan Cameron <jic23@kernel.org> Acked-by: Daniel Baluta <daniel.baluta@intel.com> Tested-by: Crestez Dan Leonard <leonard.crestez@intel.com> Signed-off-by: Peter Rosin <peda@axentia.se> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-05-05 04:15:31 +08:00
struct iio_dev *indio_dev = i2c_mux_priv(muxc);
struct inv_mpu6050_state *st = iio_priv(indio_dev);
int ret;
mutex_lock(&st->lock);
ret = inv_mpu6050_set_power_itg(st, true);
if (ret)
goto error_unlock;
ret = regmap_write(st->map, st->reg->int_pin_cfg,
st->irq_mask | INV_MPU6050_BIT_BYPASS_EN);
error_unlock:
mutex_unlock(&st->lock);
return ret;
}
static int inv_mpu6050_deselect_bypass(struct i2c_mux_core *muxc, u32 chan_id)
{
iio: imu: inv_mpu6050: change the i2c gate to be mux-locked The root i2c adapter lock is then no longer held by the i2c mux during accesses behind the i2c gate, and such accesses need to take that lock just like any other ordinary i2c accesses do. So, declare the i2c gate mux-locked, and zap the code that makes the unlocked i2c accesses and just use ordinary regmap_write accesses. This also happens to fix the deadlock described in http://patchwork.ozlabs.org/patch/584776/ authored by Adriana Reus <adriana.reus@intel.com> and submitted by Daniel Baluta <daniel.baluta@intel.com> ----------8<---------- iio: imu: inv_mpu6050: Fix deadlock between i2c adapter lock and mpu lock This deadlock occurs if the accel/gyro and the sensor on the auxiliary I2C (in my setup it's an ak8975) are working at the same time. Scenario: T1 T2 ==== ==== inv_mpu6050_read_fifo aux sensor op (eg. ak8975_read_raw) | | mutex_lock(&indio_dev->mlock) i2c_transfer | | i2c transaction i2c adapter lock | | i2c adapter lock i2c_mux_master_xfer | inv_mpu6050_select_bypass | mutex_lock(&indio_dev->mlock) When we operate on an mpu sensor the order of locking is mpu lock followed by the i2c adapter lock. However, when we operate the auxiliary sensor the order of locking is the other way around. ... ----------8<---------- The reason this patch fixes the deadlock is that T2 does not grab the i2c adapter lock until the very end (and grabs the newfangled i2c mux lock where it previously grabbed the i2c adapter lock). Acked-by: Jonathan Cameron <jic23@kernel.org> Acked-by: Daniel Baluta <daniel.baluta@intel.com> Tested-by: Crestez Dan Leonard <leonard.crestez@intel.com> Signed-off-by: Peter Rosin <peda@axentia.se> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-05-05 04:15:31 +08:00
struct iio_dev *indio_dev = i2c_mux_priv(muxc);
struct inv_mpu6050_state *st = iio_priv(indio_dev);
mutex_lock(&st->lock);
/* It doesn't really matter if any of the calls fail */
regmap_write(st->map, st->reg->int_pin_cfg, st->irq_mask);
inv_mpu6050_set_power_itg(st, false);
mutex_unlock(&st->lock);
return 0;
}
static const char *inv_mpu_match_acpi_device(struct device *dev,
enum inv_devices *chip_id)
{
const struct acpi_device_id *id;
id = acpi_match_device(dev->driver->acpi_match_table, dev);
if (!id)
return NULL;
*chip_id = (int)id->driver_data;
return dev_name(dev);
}
static bool inv_mpu_i2c_aux_bus(struct device *dev)
{
struct inv_mpu6050_state *st = iio_priv(dev_get_drvdata(dev));
switch (st->chip_type) {
case INV_ICM20608:
case INV_ICM20602:
/* no i2c auxiliary bus on the chip */
return false;
case INV_MPU9150:
case INV_MPU9250:
case INV_MPU9255:
if (st->magn_disabled)
return true;
else
return false;
default:
return true;
}
}
/*
* MPU9xxx magnetometer support requires to disable i2c auxiliary bus support.
* To ensure backward compatibility with existing setups, do not disable
* i2c auxiliary bus if it used.
* Check for i2c-gate node in devicetree and set magnetometer disabled.
* Only MPU6500 is supported by ACPI, no need to check.
*/
static int inv_mpu_magn_disable(struct iio_dev *indio_dev)
{
struct inv_mpu6050_state *st = iio_priv(indio_dev);
struct device *dev = indio_dev->dev.parent;
struct device_node *mux_node;
switch (st->chip_type) {
case INV_MPU9150:
case INV_MPU9250:
case INV_MPU9255:
mux_node = of_get_child_by_name(dev->of_node, "i2c-gate");
if (mux_node != NULL) {
st->magn_disabled = true;
dev_warn(dev, "disable internal use of magnetometer\n");
}
of_node_put(mux_node);
break;
default:
break;
}
return 0;
}
/**
* inv_mpu_probe() - probe function.
* @client: i2c client.
* @id: i2c device id.
*
* Returns 0 on success, a negative error code otherwise.
*/
static int inv_mpu_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct inv_mpu6050_state *st;
int result;
enum inv_devices chip_type;
struct regmap *regmap;
const char *name;
if (!i2c_check_functionality(client->adapter,
I2C_FUNC_SMBUS_I2C_BLOCK))
return -EOPNOTSUPP;
if (client->dev.of_node) {
chip_type = (enum inv_devices)
of_device_get_match_data(&client->dev);
name = client->name;
} else if (id) {
chip_type = (enum inv_devices)
id->driver_data;
name = id->name;
} else if (ACPI_HANDLE(&client->dev)) {
name = inv_mpu_match_acpi_device(&client->dev, &chip_type);
if (!name)
return -ENODEV;
} else {
return -ENOSYS;
}
regmap = devm_regmap_init_i2c(client, &inv_mpu_regmap_config);
if (IS_ERR(regmap)) {
dev_err(&client->dev, "Failed to register i2c regmap %d\n",
(int)PTR_ERR(regmap));
return PTR_ERR(regmap);
}
result = inv_mpu_core_probe(regmap, client->irq, name,
inv_mpu_magn_disable, chip_type);
if (result < 0)
return result;
st = iio_priv(dev_get_drvdata(&client->dev));
if (inv_mpu_i2c_aux_bus(&client->dev)) {
/* declare i2c auxiliary bus */
st->muxc = i2c_mux_alloc(client->adapter, &client->dev,
1, 0, I2C_MUX_LOCKED | I2C_MUX_GATE,
inv_mpu6050_select_bypass,
inv_mpu6050_deselect_bypass);
if (!st->muxc)
return -ENOMEM;
st->muxc->priv = dev_get_drvdata(&client->dev);
result = i2c_mux_add_adapter(st->muxc, 0, 0, 0);
if (result)
return result;
result = inv_mpu_acpi_create_mux_client(client);
if (result)
goto out_del_mux;
}
return 0;
out_del_mux:
i2c_mux_del_adapters(st->muxc);
return result;
}
static int inv_mpu_remove(struct i2c_client *client)
{
struct iio_dev *indio_dev = i2c_get_clientdata(client);
struct inv_mpu6050_state *st = iio_priv(indio_dev);
if (st->muxc) {
inv_mpu_acpi_delete_mux_client(client);
i2c_mux_del_adapters(st->muxc);
}
return 0;
}
/*
* device id table is used to identify what device can be
* supported by this driver
*/
static const struct i2c_device_id inv_mpu_id[] = {
{"mpu6050", INV_MPU6050},
{"mpu6500", INV_MPU6500},
{"mpu6515", INV_MPU6515},
{"mpu9150", INV_MPU9150},
{"mpu9250", INV_MPU9250},
{"mpu9255", INV_MPU9255},
{"icm20608", INV_ICM20608},
{"icm20602", INV_ICM20602},
{}
};
MODULE_DEVICE_TABLE(i2c, inv_mpu_id);
static const struct of_device_id inv_of_match[] = {
{
.compatible = "invensense,mpu6050",
.data = (void *)INV_MPU6050
},
{
.compatible = "invensense,mpu6500",
.data = (void *)INV_MPU6500
},
{
.compatible = "invensense,mpu6515",
.data = (void *)INV_MPU6515
},
{
.compatible = "invensense,mpu9150",
.data = (void *)INV_MPU9150
},
{
.compatible = "invensense,mpu9250",
.data = (void *)INV_MPU9250
},
{
.compatible = "invensense,mpu9255",
.data = (void *)INV_MPU9255
},
{
.compatible = "invensense,icm20608",
.data = (void *)INV_ICM20608
},
{
.compatible = "invensense,icm20602",
.data = (void *)INV_ICM20602
},
{ }
};
MODULE_DEVICE_TABLE(of, inv_of_match);
static const struct acpi_device_id inv_acpi_match[] = {
{"INVN6500", INV_MPU6500},
{ },
};
MODULE_DEVICE_TABLE(acpi, inv_acpi_match);
static struct i2c_driver inv_mpu_driver = {
.probe = inv_mpu_probe,
.remove = inv_mpu_remove,
.id_table = inv_mpu_id,
.driver = {
.of_match_table = inv_of_match,
.acpi_match_table = ACPI_PTR(inv_acpi_match),
.name = "inv-mpu6050-i2c",
.pm = &inv_mpu_pmops,
},
};
module_i2c_driver(inv_mpu_driver);
MODULE_AUTHOR("Invensense Corporation");
MODULE_DESCRIPTION("Invensense device MPU6050 driver");
MODULE_LICENSE("GPL");