diff options
Diffstat (limited to 'drivers/iio/imu/inv_mpu6050/inv_mpu_i2c.c')
| -rw-r--r-- | drivers/iio/imu/inv_mpu6050/inv_mpu_i2c.c | 208 |
1 files changed, 208 insertions, 0 deletions
diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_i2c.c b/drivers/iio/imu/inv_mpu6050/inv_mpu_i2c.c new file mode 100644 index 000000000000..f581256d9d4c --- /dev/null +++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_i2c.c @@ -0,0 +1,208 @@ +/* +* Copyright (C) 2012 Invensense, Inc. +* +* This software is licensed under the terms of the GNU General Public +* License version 2, as published by the Free Software Foundation, and +* may be copied, distributed, and modified under those terms. +* +* This program is distributed in the hope that it will be useful, +* but WITHOUT ANY WARRANTY; without even the implied warranty of +* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +* GNU General Public License for more details. +*/ + +#include <linux/acpi.h> +#include <linux/delay.h> +#include <linux/err.h> +#include <linux/i2c.h> +#include <linux/i2c-mux.h> +#include <linux/iio/iio.h> +#include <linux/module.h> +#include "inv_mpu_iio.h" + +static const struct regmap_config inv_mpu_regmap_config = { + .reg_bits = 8, + .val_bits = 8, +}; + +/* + * The i2c read/write needs to happen in unlocked mode. As the parent + * adapter is common. If we use locked versions, it will fail as + * the mux adapter will lock the parent i2c adapter, while calling + * select/deselect functions. + */ +static int inv_mpu6050_write_reg_unlocked(struct i2c_client *client, + u8 reg, u8 d) +{ + int ret; + u8 buf[2] = {reg, d}; + struct i2c_msg msg[1] = { + { + .addr = client->addr, + .flags = 0, + .len = sizeof(buf), + .buf = buf, + } + }; + + ret = __i2c_transfer(client->adapter, msg, 1); + if (ret != 1) + return ret; + + return 0; +} + +static int inv_mpu6050_select_bypass(struct i2c_adapter *adap, void *mux_priv, + u32 chan_id) +{ + struct i2c_client *client = mux_priv; + struct iio_dev *indio_dev = dev_get_drvdata(&client->dev); + struct inv_mpu6050_state *st = iio_priv(indio_dev); + int ret = 0; + + /* Use the same mutex which was used everywhere to protect power-op */ + mutex_lock(&indio_dev->mlock); + if (!st->powerup_count) { + ret = inv_mpu6050_write_reg_unlocked(client, + st->reg->pwr_mgmt_1, 0); + if (ret) + goto write_error; + + usleep_range(INV_MPU6050_REG_UP_TIME_MIN, + INV_MPU6050_REG_UP_TIME_MAX); + } + if (!ret) { + st->powerup_count++; + ret = inv_mpu6050_write_reg_unlocked(client, + st->reg->int_pin_cfg, + INV_MPU6050_INT_PIN_CFG | + INV_MPU6050_BIT_BYPASS_EN); + } +write_error: + mutex_unlock(&indio_dev->mlock); + + return ret; +} + +static int inv_mpu6050_deselect_bypass(struct i2c_adapter *adap, + void *mux_priv, u32 chan_id) +{ + struct i2c_client *client = mux_priv; + struct iio_dev *indio_dev = dev_get_drvdata(&client->dev); + struct inv_mpu6050_state *st = iio_priv(indio_dev); + + mutex_lock(&indio_dev->mlock); + /* It doesn't really mattter, if any of the calls fails */ + inv_mpu6050_write_reg_unlocked(client, st->reg->int_pin_cfg, + INV_MPU6050_INT_PIN_CFG); + st->powerup_count--; + if (!st->powerup_count) + inv_mpu6050_write_reg_unlocked(client, st->reg->pwr_mgmt_1, + INV_MPU6050_BIT_SLEEP); + mutex_unlock(&indio_dev->mlock); + + 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; + const char *name = id ? id->name : NULL; + struct regmap *regmap; + + if (!i2c_check_functionality(client->adapter, + I2C_FUNC_SMBUS_I2C_BLOCK)) + return -EOPNOTSUPP; + + 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, + NULL, id->driver_data); + if (result < 0) + return result; + + st = iio_priv(dev_get_drvdata(&client->dev)); + st->mux_adapter = i2c_add_mux_adapter(client->adapter, + &client->dev, + client, + 0, 0, 0, + inv_mpu6050_select_bypass, + inv_mpu6050_deselect_bypass); + if (!st->mux_adapter) { + result = -ENODEV; + goto out_unreg_device; + } + + result = inv_mpu_acpi_create_mux_client(client); + if (result) + goto out_del_mux; + + return 0; + +out_del_mux: + i2c_del_mux_adapter(st->mux_adapter); +out_unreg_device: + inv_mpu_core_remove(&client->dev); + 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); + + inv_mpu_acpi_delete_mux_client(client); + i2c_del_mux_adapter(st->mux_adapter); + + return inv_mpu_core_remove(&client->dev); +} + +/* + * 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}, + {} +}; + +MODULE_DEVICE_TABLE(i2c, inv_mpu_id); + +static const struct acpi_device_id inv_acpi_match[] = { + {"INVN6500", 0}, + { }, +}; + +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 = { + .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"); |