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iio: Add Freescale MPL3115A2 pressure / temperature sensor driver
I2C-controlled MEMS sensor with 20-bit pressure measurement (pascal) and 12-bit temperature measurement driver only exposes basic functionality, see TODO remarks datasheet: http://cache.freescale.com/files/sensors/doc/data_sheet/MPL3115A2.pdf v2: * store 20-bit value in 32-bit buffer element (instead of 24-bit) * zero buffer to prevent kernel data leak to userspace * fix mutex unlock in trigger handler (thanks Andi Shyti) Signed-off-by: Peter Meerwald <pmeerw@pmeerw.net> Reviewed-by: Andi Shyti <andi@etezian.org> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
This commit is contained in:
Peter Meerwald
Jonathan Cameron
parent
a35e1fd268
commit
cc26ad455f
@ -5,6 +5,18 @@
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menu "Pressure sensors"
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config MPL3115
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tristate "Freescale MPL3115A2 pressure sensor driver"
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depends on I2C
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select IIO_BUFFER
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select IIO_TRIGGERED_BUFFER
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help
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Say yes here to build support for the Freescale MPL3115A2
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pressure sensor / altimeter.
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To compile this driver as a module, choose M here: the module
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will be called mpl3115.
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config IIO_ST_PRESS
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tristate "STMicroelectronics pressure sensor Driver"
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depends on (I2C || SPI_MASTER) && SYSFS
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@ -3,6 +3,7 @@
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#
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# When adding new entries keep the list in alphabetical order
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obj-$(CONFIG_MPL3115) += mpl3115.o
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obj-$(CONFIG_IIO_ST_PRESS) += st_pressure.o
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st_pressure-y := st_pressure_core.o
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st_pressure-$(CONFIG_IIO_BUFFER) += st_pressure_buffer.o
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329
drivers/iio/pressure/mpl3115.c
Normal file
329
drivers/iio/pressure/mpl3115.c
Normal file
@ -0,0 +1,329 @@
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/*
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* mpl3115.c - Support for Freescale MPL3115A2 pressure/temperature sensor
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*
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* Copyright (c) 2013 Peter Meerwald <pmeerw@pmeerw.net>
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*
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* This file is subject to the terms and conditions of version 2 of
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* the GNU General Public License. See the file COPYING in the main
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* directory of this archive for more details.
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*
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* (7-bit I2C slave address 0x60)
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*
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* TODO: FIFO buffer, altimeter mode, oversampling, continuous mode,
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* interrupts, user offset correction, raw mode
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*/
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#include <linux/module.h>
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#include <linux/i2c.h>
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#include <linux/iio/iio.h>
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#include <linux/iio/sysfs.h>
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#include <linux/iio/trigger_consumer.h>
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#include <linux/iio/buffer.h>
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#include <linux/iio/triggered_buffer.h>
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#include <linux/delay.h>
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#define MPL3115_STATUS 0x00
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#define MPL3115_OUT_PRESS 0x01 /* MSB first, 20 bit */
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#define MPL3115_OUT_TEMP 0x04 /* MSB first, 12 bit */
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#define MPL3115_WHO_AM_I 0x0c
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#define MPL3115_CTRL_REG1 0x26
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#define MPL3115_DEVICE_ID 0xc4
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#define MPL3115_STATUS_PRESS_RDY BIT(2)
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#define MPL3115_STATUS_TEMP_RDY BIT(1)
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#define MPL3115_CTRL_RESET BIT(2) /* software reset */
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#define MPL3115_CTRL_OST BIT(1) /* initiate measurement */
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#define MPL3115_CTRL_ACTIVE BIT(0) /* continuous measurement */
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#define MPL3115_CTRL_OS_258MS (BIT(5) | BIT(4)) /* 64x oversampling */
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struct mpl3115_data {
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struct i2c_client *client;
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struct mutex lock;
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u8 ctrl_reg1;
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};
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static int mpl3115_request(struct mpl3115_data *data)
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{
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int ret, tries = 15;
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/* trigger measurement */
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ret = i2c_smbus_write_byte_data(data->client, MPL3115_CTRL_REG1,
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data->ctrl_reg1 | MPL3115_CTRL_OST);
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if (ret < 0)
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return ret;
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while (tries-- > 0) {
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ret = i2c_smbus_read_byte_data(data->client, MPL3115_CTRL_REG1);
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if (ret < 0)
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return ret;
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/* wait for data ready, i.e. OST cleared */
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if (!(ret & MPL3115_CTRL_OST))
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break;
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msleep(20);
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}
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if (tries < 0) {
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dev_err(&data->client->dev, "data not ready\n");
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return -EIO;
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}
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return 0;
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}
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static int mpl3115_read_raw(struct iio_dev *indio_dev,
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struct iio_chan_spec const *chan,
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int *val, int *val2, long mask)
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{
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struct mpl3115_data *data = iio_priv(indio_dev);
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s32 tmp = 0;
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int ret;
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switch (mask) {
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case IIO_CHAN_INFO_RAW:
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if (iio_buffer_enabled(indio_dev))
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return -EBUSY;
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switch (chan->type) {
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case IIO_PRESSURE: /* in 0.25 pascal / LSB */
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mutex_lock(&data->lock);
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ret = mpl3115_request(data);
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if (ret < 0) {
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mutex_unlock(&data->lock);
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return ret;
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}
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ret = i2c_smbus_read_i2c_block_data(data->client,
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MPL3115_OUT_PRESS, 3, (u8 *) &tmp);
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mutex_unlock(&data->lock);
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if (ret < 0)
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return ret;
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*val = sign_extend32(be32_to_cpu(tmp) >> 12, 23);
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return IIO_VAL_INT;
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case IIO_TEMP: /* in 0.0625 celsius / LSB */
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mutex_lock(&data->lock);
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ret = mpl3115_request(data);
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if (ret < 0) {
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mutex_unlock(&data->lock);
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return ret;
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}
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ret = i2c_smbus_read_i2c_block_data(data->client,
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MPL3115_OUT_TEMP, 2, (u8 *) &tmp);
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mutex_unlock(&data->lock);
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if (ret < 0)
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return ret;
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*val = sign_extend32(be32_to_cpu(tmp) >> 20, 15);
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return IIO_VAL_INT;
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default:
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return -EINVAL;
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}
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case IIO_CHAN_INFO_SCALE:
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switch (chan->type) {
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case IIO_PRESSURE:
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*val = 0;
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*val2 = 250; /* want kilopascal */
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return IIO_VAL_INT_PLUS_MICRO;
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case IIO_TEMP:
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*val = 0;
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*val2 = 62500;
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return IIO_VAL_INT_PLUS_MICRO;
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default:
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return -EINVAL;
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}
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}
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return -EINVAL;
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}
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static irqreturn_t mpl3115_trigger_handler(int irq, void *p)
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{
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struct iio_poll_func *pf = p;
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struct iio_dev *indio_dev = pf->indio_dev;
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struct mpl3115_data *data = iio_priv(indio_dev);
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u8 buffer[16]; /* 32-bit channel + 16-bit channel + padding + ts */
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int ret, pos = 0;
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mutex_lock(&data->lock);
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ret = mpl3115_request(data);
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if (ret < 0) {
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mutex_unlock(&data->lock);
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goto done;
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}
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memset(buffer, 0, sizeof(buffer));
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if (test_bit(0, indio_dev->active_scan_mask)) {
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ret = i2c_smbus_read_i2c_block_data(data->client,
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MPL3115_OUT_PRESS, 3, &buffer[pos]);
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if (ret < 0) {
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mutex_unlock(&data->lock);
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goto done;
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}
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pos += 4;
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}
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if (test_bit(1, indio_dev->active_scan_mask)) {
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ret = i2c_smbus_read_i2c_block_data(data->client,
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MPL3115_OUT_TEMP, 2, &buffer[pos]);
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if (ret < 0) {
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mutex_unlock(&data->lock);
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goto done;
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}
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}
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mutex_unlock(&data->lock);
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iio_push_to_buffers_with_timestamp(indio_dev, buffer,
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iio_get_time_ns());
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done:
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iio_trigger_notify_done(indio_dev->trig);
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return IRQ_HANDLED;
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}
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static const struct iio_chan_spec mpl3115_channels[] = {
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{
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.type = IIO_PRESSURE,
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.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
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BIT(IIO_CHAN_INFO_SCALE),
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.scan_index = 0,
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.scan_type = {
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.sign = 's',
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.realbits = 20,
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.storagebits = 32,
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.shift = 12,
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.endianness = IIO_BE,
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}
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},
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{
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.type = IIO_TEMP,
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.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
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BIT(IIO_CHAN_INFO_SCALE),
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.scan_index = 1,
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.scan_type = {
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.sign = 's',
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.realbits = 12,
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.storagebits = 16,
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.shift = 4,
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.endianness = IIO_BE,
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}
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},
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IIO_CHAN_SOFT_TIMESTAMP(2),
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};
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static const struct iio_info mpl3115_info = {
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.read_raw = &mpl3115_read_raw,
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.driver_module = THIS_MODULE,
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};
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static int mpl3115_probe(struct i2c_client *client,
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const struct i2c_device_id *id)
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{
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struct mpl3115_data *data;
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struct iio_dev *indio_dev;
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int ret;
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ret = i2c_smbus_read_byte_data(client, MPL3115_WHO_AM_I);
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if (ret < 0)
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return ret;
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if (ret != MPL3115_DEVICE_ID)
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return -ENODEV;
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indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
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if (!indio_dev)
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return -ENOMEM;
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data = iio_priv(indio_dev);
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data->client = client;
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mutex_init(&data->lock);
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i2c_set_clientdata(client, indio_dev);
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indio_dev->info = &mpl3115_info;
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indio_dev->name = id->name;
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indio_dev->dev.parent = &client->dev;
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indio_dev->modes = INDIO_DIRECT_MODE;
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indio_dev->channels = mpl3115_channels;
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indio_dev->num_channels = ARRAY_SIZE(mpl3115_channels);
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/* software reset, I2C transfer is aborted (fails) */
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i2c_smbus_write_byte_data(client, MPL3115_CTRL_REG1,
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MPL3115_CTRL_RESET);
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msleep(50);
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data->ctrl_reg1 = MPL3115_CTRL_OS_258MS;
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ret = i2c_smbus_write_byte_data(client, MPL3115_CTRL_REG1,
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data->ctrl_reg1);
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if (ret < 0)
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return ret;
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ret = iio_triggered_buffer_setup(indio_dev, NULL,
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mpl3115_trigger_handler, NULL);
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if (ret < 0)
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return ret;
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ret = iio_device_register(indio_dev);
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if (ret < 0)
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goto buffer_cleanup;
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return 0;
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buffer_cleanup:
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iio_triggered_buffer_cleanup(indio_dev);
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return ret;
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}
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static int mpl3115_standby(struct mpl3115_data *data)
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{
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return i2c_smbus_write_byte_data(data->client, MPL3115_CTRL_REG1,
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data->ctrl_reg1 & ~MPL3115_CTRL_ACTIVE);
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}
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static int mpl3115_remove(struct i2c_client *client)
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{
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struct iio_dev *indio_dev = i2c_get_clientdata(client);
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iio_device_unregister(indio_dev);
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iio_triggered_buffer_cleanup(indio_dev);
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mpl3115_standby(iio_priv(indio_dev));
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return 0;
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}
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#ifdef CONFIG_PM_SLEEP
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static int mpl3115_suspend(struct device *dev)
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{
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return mpl3115_standby(iio_priv(i2c_get_clientdata(
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to_i2c_client(dev))));
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}
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static int mpl3115_resume(struct device *dev)
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{
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struct mpl3115_data *data = iio_priv(i2c_get_clientdata(
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to_i2c_client(dev)));
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return i2c_smbus_write_byte_data(data->client, MPL3115_CTRL_REG1,
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data->ctrl_reg1);
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}
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static SIMPLE_DEV_PM_OPS(mpl3115_pm_ops, mpl3115_suspend, mpl3115_resume);
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#define MPL3115_PM_OPS (&mpl3115_pm_ops)
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#else
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#define MPL3115_PM_OPS NULL
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#endif
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static const struct i2c_device_id mpl3115_id[] = {
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{ "mpl3115", 0 },
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{ }
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};
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MODULE_DEVICE_TABLE(i2c, mpl3115_id);
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static struct i2c_driver mpl3115_driver = {
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.driver = {
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.name = "mpl3115",
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.pm = MPL3115_PM_OPS,
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},
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.probe = mpl3115_probe,
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.remove = mpl3115_remove,
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.id_table = mpl3115_id,
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};
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module_i2c_driver(mpl3115_driver);
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MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
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MODULE_DESCRIPTION("Freescale MPL3115 pressure/temperature driver");
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MODULE_LICENSE("GPL");
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