| /* |
| * mpl3115.c - Support for Freescale MPL3115A2 pressure/temperature sensor |
| * |
| * Copyright (c) 2013 Peter Meerwald <pmeerw@pmeerw.net> |
| * |
| * This file is subject to the terms and conditions of version 2 of |
| * the GNU General Public License. See the file COPYING in the main |
| * directory of this archive for more details. |
| * |
| * (7-bit I2C slave address 0x60) |
| * |
| * TODO: FIFO buffer, altimeter mode, oversampling, continuous mode, |
| * interrupts, user offset correction, raw mode |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/i2c.h> |
| #include <linux/iio/iio.h> |
| #include <linux/iio/sysfs.h> |
| #include <linux/iio/trigger_consumer.h> |
| #include <linux/iio/buffer.h> |
| #include <linux/iio/triggered_buffer.h> |
| #include <linux/delay.h> |
| |
| #define MPL3115_STATUS 0x00 |
| #define MPL3115_OUT_PRESS 0x01 /* MSB first, 20 bit */ |
| #define MPL3115_OUT_TEMP 0x04 /* MSB first, 12 bit */ |
| #define MPL3115_WHO_AM_I 0x0c |
| #define MPL3115_CTRL_REG1 0x26 |
| |
| #define MPL3115_DEVICE_ID 0xc4 |
| |
| #define MPL3115_STATUS_PRESS_RDY BIT(2) |
| #define MPL3115_STATUS_TEMP_RDY BIT(1) |
| |
| #define MPL3115_CTRL_RESET BIT(2) /* software reset */ |
| #define MPL3115_CTRL_OST BIT(1) /* initiate measurement */ |
| #define MPL3115_CTRL_ACTIVE BIT(0) /* continuous measurement */ |
| #define MPL3115_CTRL_OS_258MS (BIT(5) | BIT(4)) /* 64x oversampling */ |
| |
| struct mpl3115_data { |
| struct i2c_client *client; |
| struct mutex lock; |
| u8 ctrl_reg1; |
| }; |
| |
| static int mpl3115_request(struct mpl3115_data *data) |
| { |
| int ret, tries = 15; |
| |
| /* trigger measurement */ |
| ret = i2c_smbus_write_byte_data(data->client, MPL3115_CTRL_REG1, |
| data->ctrl_reg1 | MPL3115_CTRL_OST); |
| if (ret < 0) |
| return ret; |
| |
| while (tries-- > 0) { |
| ret = i2c_smbus_read_byte_data(data->client, MPL3115_CTRL_REG1); |
| if (ret < 0) |
| return ret; |
| /* wait for data ready, i.e. OST cleared */ |
| if (!(ret & MPL3115_CTRL_OST)) |
| break; |
| msleep(20); |
| } |
| |
| if (tries < 0) { |
| dev_err(&data->client->dev, "data not ready\n"); |
| return -EIO; |
| } |
| |
| return 0; |
| } |
| |
| static int mpl3115_read_raw(struct iio_dev *indio_dev, |
| struct iio_chan_spec const *chan, |
| int *val, int *val2, long mask) |
| { |
| struct mpl3115_data *data = iio_priv(indio_dev); |
| __be32 tmp = 0; |
| int ret; |
| |
| switch (mask) { |
| case IIO_CHAN_INFO_RAW: |
| ret = iio_device_claim_direct_mode(indio_dev); |
| if (ret) |
| return ret; |
| |
| switch (chan->type) { |
| case IIO_PRESSURE: /* in 0.25 pascal / LSB */ |
| mutex_lock(&data->lock); |
| ret = mpl3115_request(data); |
| if (ret < 0) { |
| mutex_unlock(&data->lock); |
| break; |
| } |
| ret = i2c_smbus_read_i2c_block_data(data->client, |
| MPL3115_OUT_PRESS, 3, (u8 *) &tmp); |
| mutex_unlock(&data->lock); |
| if (ret < 0) |
| break; |
| *val = be32_to_cpu(tmp) >> 12; |
| ret = IIO_VAL_INT; |
| break; |
| case IIO_TEMP: /* in 0.0625 celsius / LSB */ |
| mutex_lock(&data->lock); |
| ret = mpl3115_request(data); |
| if (ret < 0) { |
| mutex_unlock(&data->lock); |
| break; |
| } |
| ret = i2c_smbus_read_i2c_block_data(data->client, |
| MPL3115_OUT_TEMP, 2, (u8 *) &tmp); |
| mutex_unlock(&data->lock); |
| if (ret < 0) |
| break; |
| *val = sign_extend32(be32_to_cpu(tmp) >> 20, 11); |
| ret = IIO_VAL_INT; |
| break; |
| default: |
| ret = -EINVAL; |
| break; |
| } |
| |
| iio_device_release_direct_mode(indio_dev); |
| return ret; |
| |
| case IIO_CHAN_INFO_SCALE: |
| switch (chan->type) { |
| case IIO_PRESSURE: |
| *val = 0; |
| *val2 = 250; /* want kilopascal */ |
| return IIO_VAL_INT_PLUS_MICRO; |
| case IIO_TEMP: |
| *val = 0; |
| *val2 = 62500; |
| return IIO_VAL_INT_PLUS_MICRO; |
| default: |
| return -EINVAL; |
| } |
| } |
| return -EINVAL; |
| } |
| |
| static irqreturn_t mpl3115_trigger_handler(int irq, void *p) |
| { |
| struct iio_poll_func *pf = p; |
| struct iio_dev *indio_dev = pf->indio_dev; |
| struct mpl3115_data *data = iio_priv(indio_dev); |
| /* |
| * 32-bit channel + 16-bit channel + padding + ts |
| * Note that it is possible for only one of the first 2 |
| * channels to be enabled. If that happens, the first element |
| * of the buffer may be either 16 or 32-bits. As such we cannot |
| * use a simple structure definition to express this data layout. |
| */ |
| u8 buffer[16] __aligned(8); |
| int ret, pos = 0; |
| |
| mutex_lock(&data->lock); |
| ret = mpl3115_request(data); |
| if (ret < 0) { |
| mutex_unlock(&data->lock); |
| goto done; |
| } |
| |
| memset(buffer, 0, sizeof(buffer)); |
| if (test_bit(0, indio_dev->active_scan_mask)) { |
| ret = i2c_smbus_read_i2c_block_data(data->client, |
| MPL3115_OUT_PRESS, 3, &buffer[pos]); |
| if (ret < 0) { |
| mutex_unlock(&data->lock); |
| goto done; |
| } |
| pos += 4; |
| } |
| |
| if (test_bit(1, indio_dev->active_scan_mask)) { |
| ret = i2c_smbus_read_i2c_block_data(data->client, |
| MPL3115_OUT_TEMP, 2, &buffer[pos]); |
| if (ret < 0) { |
| mutex_unlock(&data->lock); |
| goto done; |
| } |
| } |
| mutex_unlock(&data->lock); |
| |
| iio_push_to_buffers_with_timestamp(indio_dev, buffer, |
| iio_get_time_ns(indio_dev)); |
| |
| done: |
| iio_trigger_notify_done(indio_dev->trig); |
| return IRQ_HANDLED; |
| } |
| |
| static const struct iio_chan_spec mpl3115_channels[] = { |
| { |
| .type = IIO_PRESSURE, |
| .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), |
| .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), |
| .scan_index = 0, |
| .scan_type = { |
| .sign = 'u', |
| .realbits = 20, |
| .storagebits = 32, |
| .shift = 12, |
| .endianness = IIO_BE, |
| } |
| }, |
| { |
| .type = IIO_TEMP, |
| .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), |
| .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), |
| .scan_index = 1, |
| .scan_type = { |
| .sign = 's', |
| .realbits = 12, |
| .storagebits = 16, |
| .shift = 4, |
| .endianness = IIO_BE, |
| } |
| }, |
| IIO_CHAN_SOFT_TIMESTAMP(2), |
| }; |
| |
| static const struct iio_info mpl3115_info = { |
| .read_raw = &mpl3115_read_raw, |
| .driver_module = THIS_MODULE, |
| }; |
| |
| static int mpl3115_probe(struct i2c_client *client, |
| const struct i2c_device_id *id) |
| { |
| struct mpl3115_data *data; |
| struct iio_dev *indio_dev; |
| int ret; |
| |
| ret = i2c_smbus_read_byte_data(client, MPL3115_WHO_AM_I); |
| if (ret < 0) |
| return ret; |
| if (ret != MPL3115_DEVICE_ID) |
| return -ENODEV; |
| |
| indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); |
| if (!indio_dev) |
| return -ENOMEM; |
| |
| data = iio_priv(indio_dev); |
| data->client = client; |
| mutex_init(&data->lock); |
| |
| i2c_set_clientdata(client, indio_dev); |
| indio_dev->info = &mpl3115_info; |
| indio_dev->name = id->name; |
| indio_dev->dev.parent = &client->dev; |
| indio_dev->modes = INDIO_DIRECT_MODE; |
| indio_dev->channels = mpl3115_channels; |
| indio_dev->num_channels = ARRAY_SIZE(mpl3115_channels); |
| |
| /* software reset, I2C transfer is aborted (fails) */ |
| i2c_smbus_write_byte_data(client, MPL3115_CTRL_REG1, |
| MPL3115_CTRL_RESET); |
| msleep(50); |
| |
| data->ctrl_reg1 = MPL3115_CTRL_OS_258MS; |
| ret = i2c_smbus_write_byte_data(client, MPL3115_CTRL_REG1, |
| data->ctrl_reg1); |
| if (ret < 0) |
| return ret; |
| |
| ret = iio_triggered_buffer_setup(indio_dev, NULL, |
| mpl3115_trigger_handler, NULL); |
| if (ret < 0) |
| return ret; |
| |
| ret = iio_device_register(indio_dev); |
| if (ret < 0) |
| goto buffer_cleanup; |
| return 0; |
| |
| buffer_cleanup: |
| iio_triggered_buffer_cleanup(indio_dev); |
| return ret; |
| } |
| |
| static int mpl3115_standby(struct mpl3115_data *data) |
| { |
| return i2c_smbus_write_byte_data(data->client, MPL3115_CTRL_REG1, |
| data->ctrl_reg1 & ~MPL3115_CTRL_ACTIVE); |
| } |
| |
| static int mpl3115_remove(struct i2c_client *client) |
| { |
| struct iio_dev *indio_dev = i2c_get_clientdata(client); |
| |
| iio_device_unregister(indio_dev); |
| iio_triggered_buffer_cleanup(indio_dev); |
| mpl3115_standby(iio_priv(indio_dev)); |
| |
| return 0; |
| } |
| |
| #ifdef CONFIG_PM_SLEEP |
| static int mpl3115_suspend(struct device *dev) |
| { |
| return mpl3115_standby(iio_priv(i2c_get_clientdata( |
| to_i2c_client(dev)))); |
| } |
| |
| static int mpl3115_resume(struct device *dev) |
| { |
| struct mpl3115_data *data = iio_priv(i2c_get_clientdata( |
| to_i2c_client(dev))); |
| |
| return i2c_smbus_write_byte_data(data->client, MPL3115_CTRL_REG1, |
| data->ctrl_reg1); |
| } |
| |
| static SIMPLE_DEV_PM_OPS(mpl3115_pm_ops, mpl3115_suspend, mpl3115_resume); |
| #define MPL3115_PM_OPS (&mpl3115_pm_ops) |
| #else |
| #define MPL3115_PM_OPS NULL |
| #endif |
| |
| static const struct i2c_device_id mpl3115_id[] = { |
| { "mpl3115", 0 }, |
| { } |
| }; |
| MODULE_DEVICE_TABLE(i2c, mpl3115_id); |
| |
| static const struct of_device_id mpl3115_of_match[] = { |
| { .compatible = "fsl,mpl3115" }, |
| { } |
| }; |
| MODULE_DEVICE_TABLE(of, mpl3115_of_match); |
| |
| static struct i2c_driver mpl3115_driver = { |
| .driver = { |
| .name = "mpl3115", |
| .of_match_table = mpl3115_of_match, |
| .pm = MPL3115_PM_OPS, |
| }, |
| .probe = mpl3115_probe, |
| .remove = mpl3115_remove, |
| .id_table = mpl3115_id, |
| }; |
| module_i2c_driver(mpl3115_driver); |
| |
| MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>"); |
| MODULE_DESCRIPTION("Freescale MPL3115 pressure/temperature driver"); |
| MODULE_LICENSE("GPL"); |