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linux/drivers/iio/accel/mma8452.c
Martin Kepplinger 60f562e74e iio: mma8452: add freefall / motion interrupt source 
This adds the freefall / motion interrupt source definitions to the driver.
It is used in this series' next patch, for chips that don't support the
transient interrupt source.

Signed-off-by: Martin Kepplinger <martin.kepplinger@theobroma-systems.com>
Signed-off-by: Christoph Muellner <christoph.muellner@theobroma-systems.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2015-09-23 20:23:21 +01:00

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/*
* mma8452.c - Support for following Freescale 3-axis accelerometers:
*
* MMA8452Q (12 bit)
* MMA8453Q (10 bit)
*
* Copyright 2014 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 0x1c/0x1d (pin selectable)
*
* TODO: orientation / freefall events, autosleep
*/
#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/buffer.h>
#include <linux/iio/trigger.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/triggered_buffer.h>
#include <linux/iio/events.h>
#include <linux/delay.h>
#include <linux/of_device.h>
#define MMA8452_STATUS 0x00
#define MMA8452_STATUS_DRDY (BIT(2) | BIT(1) | BIT(0))
#define MMA8452_OUT_X 0x01 /* MSB first */
#define MMA8452_OUT_Y 0x03
#define MMA8452_OUT_Z 0x05
#define MMA8452_INT_SRC 0x0c
#define MMA8452_WHO_AM_I 0x0d
#define MMA8452_DATA_CFG 0x0e
#define MMA8452_DATA_CFG_FS_MASK GENMASK(1, 0)
#define MMA8452_DATA_CFG_FS_2G 0
#define MMA8452_DATA_CFG_FS_4G 1
#define MMA8452_DATA_CFG_FS_8G 2
#define MMA8452_DATA_CFG_HPF_MASK BIT(4)
#define MMA8452_HP_FILTER_CUTOFF 0x0f
#define MMA8452_HP_FILTER_CUTOFF_SEL_MASK GENMASK(1, 0)
#define MMA8452_FF_MT_CFG 0x15
#define MMA8452_FF_MT_CFG_OAE BIT(6)
#define MMA8452_FF_MT_CFG_ELE BIT(7)
#define MMA8452_FF_MT_SRC 0x16
#define MMA8452_FF_MT_SRC_XHE BIT(1)
#define MMA8452_FF_MT_SRC_YHE BIT(3)
#define MMA8452_FF_MT_SRC_ZHE BIT(5)
#define MMA8452_FF_MT_THS 0x17
#define MMA8452_FF_MT_THS_MASK 0x7f
#define MMA8452_FF_MT_COUNT 0x18
#define MMA8452_TRANSIENT_CFG 0x1d
#define MMA8452_TRANSIENT_CFG_HPF_BYP BIT(0)
#define MMA8452_TRANSIENT_CFG_CHAN(chan) BIT(chan + 1)
#define MMA8452_TRANSIENT_CFG_ELE BIT(4)
#define MMA8452_TRANSIENT_SRC 0x1e
#define MMA8452_TRANSIENT_SRC_XTRANSE BIT(1)
#define MMA8452_TRANSIENT_SRC_YTRANSE BIT(3)
#define MMA8452_TRANSIENT_SRC_ZTRANSE BIT(5)
#define MMA8452_TRANSIENT_THS 0x1f
#define MMA8452_TRANSIENT_THS_MASK GENMASK(6, 0)
#define MMA8452_TRANSIENT_COUNT 0x20
#define MMA8452_CTRL_REG1 0x2a
#define MMA8452_CTRL_ACTIVE BIT(0)
#define MMA8452_CTRL_DR_MASK GENMASK(5, 3)
#define MMA8452_CTRL_DR_SHIFT 3
#define MMA8452_CTRL_DR_DEFAULT 0x4 /* 50 Hz sample frequency */
#define MMA8452_CTRL_REG2 0x2b
#define MMA8452_CTRL_REG2_RST BIT(6)
#define MMA8452_CTRL_REG4 0x2d
#define MMA8452_CTRL_REG5 0x2e
#define MMA8452_OFF_X 0x2f
#define MMA8452_OFF_Y 0x30
#define MMA8452_OFF_Z 0x31
#define MMA8452_MAX_REG 0x31
#define MMA8452_INT_DRDY BIT(0)
#define MMA8452_INT_FF_MT BIT(2)
#define MMA8452_INT_TRANS BIT(5)
#define MMA8452_DEVICE_ID 0x2a
#define MMA8453_DEVICE_ID 0x3a
struct mma8452_data {
struct i2c_client *client;
struct mutex lock;
u8 ctrl_reg1;
u8 data_cfg;
const struct mma_chip_info *chip_info;
};
/**
* struct mma_chip_info - chip specific data for Freescale's accelerometers
* @chip_id: WHO_AM_I register's value
* @channels: struct iio_chan_spec matching the device's
* capabilities
* @num_channels: number of channels
* @mma_scales: scale factors for converting register values
* to m/s^2; 3 modes: 2g, 4g, 8g; 2 integers
* per mode: m/s^2 and micro m/s^2
* @ev_cfg: event config register address
* @ev_cfg_ele: latch bit in event config register
* @ev_cfg_chan_shift: number of the bit to enable events in X
* direction; in event config register
* @ev_src: event source register address
* @ev_src_xe: bit in event source register that indicates
* an event in X direction
* @ev_src_ye: bit in event source register that indicates
* an event in Y direction
* @ev_src_ze: bit in event source register that indicates
* an event in Z direction
* @ev_ths: event threshold register address
* @ev_ths_mask: mask for the threshold value
* @ev_count: event count (period) register address
*
* Since not all chips supported by the driver support comparing high pass
* filtered data for events (interrupts), different interrupt sources are
* used for different chips and the relevant registers are included here.
*/
struct mma_chip_info {
u8 chip_id;
const struct iio_chan_spec *channels;
int num_channels;
const int mma_scales[3][2];
u8 ev_cfg;
u8 ev_cfg_ele;
u8 ev_cfg_chan_shift;
u8 ev_src;
u8 ev_src_xe;
u8 ev_src_ye;
u8 ev_src_ze;
u8 ev_ths;
u8 ev_ths_mask;
u8 ev_count;
};
static int mma8452_drdy(struct mma8452_data *data)
{
int tries = 150;
while (tries-- > 0) {
int ret = i2c_smbus_read_byte_data(data->client,
MMA8452_STATUS);
if (ret < 0)
return ret;
if ((ret & MMA8452_STATUS_DRDY) == MMA8452_STATUS_DRDY)
return 0;
msleep(20);
}
dev_err(&data->client->dev, "data not ready\n");
return -EIO;
}
static int mma8452_read(struct mma8452_data *data, __be16 buf[3])
{
int ret = mma8452_drdy(data);
if (ret < 0)
return ret;
return i2c_smbus_read_i2c_block_data(data->client, MMA8452_OUT_X,
3 * sizeof(__be16), (u8 *)buf);
}
static ssize_t mma8452_show_int_plus_micros(char *buf, const int (*vals)[2],
int n)
{
size_t len = 0;
while (n-- > 0)
len += scnprintf(buf + len, PAGE_SIZE - len, "%d.%06d ",
vals[n][0], vals[n][1]);
/* replace trailing space by newline */
buf[len - 1] = '\n';
return len;
}
static int mma8452_get_int_plus_micros_index(const int (*vals)[2], int n,
int val, int val2)
{
while (n-- > 0)
if (val == vals[n][0] && val2 == vals[n][1])
return n;
return -EINVAL;
}
static int mma8452_get_odr_index(struct mma8452_data *data)
{
return (data->ctrl_reg1 & MMA8452_CTRL_DR_MASK) >>
MMA8452_CTRL_DR_SHIFT;
}
static const int mma8452_samp_freq[8][2] = {
{800, 0}, {400, 0}, {200, 0}, {100, 0}, {50, 0}, {12, 500000},
{6, 250000}, {1, 560000}
};
/* Datasheet table 35 (step time vs sample frequency) */
static const int mma8452_transient_time_step_us[8] = {
1250,
2500,
5000,
10000,
20000,
20000,
20000,
20000
};
/* Datasheet table 18 (normal mode) */
static const int mma8452_hp_filter_cutoff[8][4][2] = {
{ {16, 0}, {8, 0}, {4, 0}, {2, 0} }, /* 800 Hz sample */
{ {16, 0}, {8, 0}, {4, 0}, {2, 0} }, /* 400 Hz sample */
{ {8, 0}, {4, 0}, {2, 0}, {1, 0} }, /* 200 Hz sample */
{ {4, 0}, {2, 0}, {1, 0}, {0, 500000} }, /* 100 Hz sample */
{ {2, 0}, {1, 0}, {0, 500000}, {0, 250000} }, /* 50 Hz sample */
{ {2, 0}, {1, 0}, {0, 500000}, {0, 250000} }, /* 12.5 Hz sample */
{ {2, 0}, {1, 0}, {0, 500000}, {0, 250000} }, /* 6.25 Hz sample */
{ {2, 0}, {1, 0}, {0, 500000}, {0, 250000} } /* 1.56 Hz sample */
};
static ssize_t mma8452_show_samp_freq_avail(struct device *dev,
struct device_attribute *attr,
char *buf)
{
return mma8452_show_int_plus_micros(buf, mma8452_samp_freq,
ARRAY_SIZE(mma8452_samp_freq));
}
static ssize_t mma8452_show_scale_avail(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct mma8452_data *data = iio_priv(i2c_get_clientdata(
to_i2c_client(dev)));
return mma8452_show_int_plus_micros(buf, data->chip_info->mma_scales,
ARRAY_SIZE(data->chip_info->mma_scales));
}
static ssize_t mma8452_show_hp_cutoff_avail(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct iio_dev *indio_dev = dev_to_iio_dev(dev);
struct mma8452_data *data = iio_priv(indio_dev);
int i = mma8452_get_odr_index(data);
return mma8452_show_int_plus_micros(buf, mma8452_hp_filter_cutoff[i],
ARRAY_SIZE(mma8452_hp_filter_cutoff[0]));
}
static IIO_DEV_ATTR_SAMP_FREQ_AVAIL(mma8452_show_samp_freq_avail);
static IIO_DEVICE_ATTR(in_accel_scale_available, S_IRUGO,
mma8452_show_scale_avail, NULL, 0);
static IIO_DEVICE_ATTR(in_accel_filter_high_pass_3db_frequency_available,
S_IRUGO, mma8452_show_hp_cutoff_avail, NULL, 0);
static int mma8452_get_samp_freq_index(struct mma8452_data *data,
int val, int val2)
{
return mma8452_get_int_plus_micros_index(mma8452_samp_freq,
ARRAY_SIZE(mma8452_samp_freq),
val, val2);
}
static int mma8452_get_scale_index(struct mma8452_data *data, int val, int val2)
{
return mma8452_get_int_plus_micros_index(data->chip_info->mma_scales,
ARRAY_SIZE(data->chip_info->mma_scales), val, val2);
}
static int mma8452_get_hp_filter_index(struct mma8452_data *data,
int val, int val2)
{
int i = mma8452_get_odr_index(data);
return mma8452_get_int_plus_micros_index(mma8452_hp_filter_cutoff[i],
ARRAY_SIZE(mma8452_hp_filter_cutoff[0]), val, val2);
}
static int mma8452_read_hp_filter(struct mma8452_data *data, int *hz, int *uHz)
{
int i, ret;
ret = i2c_smbus_read_byte_data(data->client, MMA8452_HP_FILTER_CUTOFF);
if (ret < 0)
return ret;
i = mma8452_get_odr_index(data);
ret &= MMA8452_HP_FILTER_CUTOFF_SEL_MASK;
*hz = mma8452_hp_filter_cutoff[i][ret][0];
*uHz = mma8452_hp_filter_cutoff[i][ret][1];
return 0;
}
static int mma8452_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
struct mma8452_data *data = iio_priv(indio_dev);
__be16 buffer[3];
int i, ret;
switch (mask) {
case IIO_CHAN_INFO_RAW:
if (iio_buffer_enabled(indio_dev))
return -EBUSY;
mutex_lock(&data->lock);
ret = mma8452_read(data, buffer);
mutex_unlock(&data->lock);
if (ret < 0)
return ret;
*val = sign_extend32(be16_to_cpu(
buffer[chan->scan_index]) >> chan->scan_type.shift,
chan->scan_type.realbits - 1);
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
i = data->data_cfg & MMA8452_DATA_CFG_FS_MASK;
*val = data->chip_info->mma_scales[i][0];
*val2 = data->chip_info->mma_scales[i][1];
return IIO_VAL_INT_PLUS_MICRO;
case IIO_CHAN_INFO_SAMP_FREQ:
i = mma8452_get_odr_index(data);
*val = mma8452_samp_freq[i][0];
*val2 = mma8452_samp_freq[i][1];
return IIO_VAL_INT_PLUS_MICRO;
case IIO_CHAN_INFO_CALIBBIAS:
ret = i2c_smbus_read_byte_data(data->client,
MMA8452_OFF_X + chan->scan_index);
if (ret < 0)
return ret;
*val = sign_extend32(ret, 7);
return IIO_VAL_INT;
case IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY:
if (data->data_cfg & MMA8452_DATA_CFG_HPF_MASK) {
ret = mma8452_read_hp_filter(data, val, val2);
if (ret < 0)
return ret;
} else {
*val = 0;
*val2 = 0;
}
return IIO_VAL_INT_PLUS_MICRO;
}
return -EINVAL;
}
static int mma8452_standby(struct mma8452_data *data)
{
return i2c_smbus_write_byte_data(data->client, MMA8452_CTRL_REG1,
data->ctrl_reg1 & ~MMA8452_CTRL_ACTIVE);
}
static int mma8452_active(struct mma8452_data *data)
{
return i2c_smbus_write_byte_data(data->client, MMA8452_CTRL_REG1,
data->ctrl_reg1);
}
static int mma8452_change_config(struct mma8452_data *data, u8 reg, u8 val)
{
int ret;
mutex_lock(&data->lock);
/* config can only be changed when in standby */
ret = mma8452_standby(data);
if (ret < 0)
goto fail;
ret = i2c_smbus_write_byte_data(data->client, reg, val);
if (ret < 0)
goto fail;
ret = mma8452_active(data);
if (ret < 0)
goto fail;
ret = 0;
fail:
mutex_unlock(&data->lock);
return ret;
}
static int mma8452_set_hp_filter_frequency(struct mma8452_data *data,
int val, int val2)
{
int i, reg;
i = mma8452_get_hp_filter_index(data, val, val2);
if (i < 0)
return i;
reg = i2c_smbus_read_byte_data(data->client,
MMA8452_HP_FILTER_CUTOFF);
if (reg < 0)
return reg;
reg &= ~MMA8452_HP_FILTER_CUTOFF_SEL_MASK;
reg |= i;
return mma8452_change_config(data, MMA8452_HP_FILTER_CUTOFF, reg);
}
static int mma8452_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int val, int val2, long mask)
{
struct mma8452_data *data = iio_priv(indio_dev);
int i, ret;
if (iio_buffer_enabled(indio_dev))
return -EBUSY;
switch (mask) {
case IIO_CHAN_INFO_SAMP_FREQ:
i = mma8452_get_samp_freq_index(data, val, val2);
if (i < 0)
return i;
data->ctrl_reg1 &= ~MMA8452_CTRL_DR_MASK;
data->ctrl_reg1 |= i << MMA8452_CTRL_DR_SHIFT;
return mma8452_change_config(data, MMA8452_CTRL_REG1,
data->ctrl_reg1);
case IIO_CHAN_INFO_SCALE:
i = mma8452_get_scale_index(data, val, val2);
if (i < 0)
return i;
data->data_cfg &= ~MMA8452_DATA_CFG_FS_MASK;
data->data_cfg |= i;
return mma8452_change_config(data, MMA8452_DATA_CFG,
data->data_cfg);
case IIO_CHAN_INFO_CALIBBIAS:
if (val < -128 || val > 127)
return -EINVAL;
return mma8452_change_config(data,
MMA8452_OFF_X + chan->scan_index,
val);
case IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY:
if (val == 0 && val2 == 0) {
data->data_cfg &= ~MMA8452_DATA_CFG_HPF_MASK;
} else {
data->data_cfg |= MMA8452_DATA_CFG_HPF_MASK;
ret = mma8452_set_hp_filter_frequency(data, val, val2);
if (ret < 0)
return ret;
}
return mma8452_change_config(data, MMA8452_DATA_CFG,
data->data_cfg);
default:
return -EINVAL;
}
}
static int mma8452_read_thresh(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan,
enum iio_event_type type,
enum iio_event_direction dir,
enum iio_event_info info,
int *val, int *val2)
{
struct mma8452_data *data = iio_priv(indio_dev);
int ret, us;
switch (info) {
case IIO_EV_INFO_VALUE:
ret = i2c_smbus_read_byte_data(data->client,
data->chip_info->ev_ths);
if (ret < 0)
return ret;
*val = ret & data->chip_info->ev_ths_mask;
return IIO_VAL_INT;
case IIO_EV_INFO_PERIOD:
ret = i2c_smbus_read_byte_data(data->client,
data->chip_info->ev_count);
if (ret < 0)
return ret;
us = ret * mma8452_transient_time_step_us[
mma8452_get_odr_index(data)];
*val = us / USEC_PER_SEC;
*val2 = us % USEC_PER_SEC;
return IIO_VAL_INT_PLUS_MICRO;
case IIO_EV_INFO_HIGH_PASS_FILTER_3DB:
ret = i2c_smbus_read_byte_data(data->client,
MMA8452_TRANSIENT_CFG);
if (ret < 0)
return ret;
if (ret & MMA8452_TRANSIENT_CFG_HPF_BYP) {
*val = 0;
*val2 = 0;
} else {
ret = mma8452_read_hp_filter(data, val, val2);
if (ret < 0)
return ret;
}
return IIO_VAL_INT_PLUS_MICRO;
default:
return -EINVAL;
}
}
static int mma8452_write_thresh(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan,
enum iio_event_type type,
enum iio_event_direction dir,
enum iio_event_info info,
int val, int val2)
{
struct mma8452_data *data = iio_priv(indio_dev);
int ret, reg, steps;
switch (info) {
case IIO_EV_INFO_VALUE:
if (val < 0 || val > MMA8452_TRANSIENT_THS_MASK)
return -EINVAL;
return mma8452_change_config(data, data->chip_info->ev_ths,
val);
case IIO_EV_INFO_PERIOD:
steps = (val * USEC_PER_SEC + val2) /
mma8452_transient_time_step_us[
mma8452_get_odr_index(data)];
if (steps < 0 || steps > 0xff)
return -EINVAL;
return mma8452_change_config(data, data->chip_info->ev_count,
steps);
case IIO_EV_INFO_HIGH_PASS_FILTER_3DB:
reg = i2c_smbus_read_byte_data(data->client,
MMA8452_TRANSIENT_CFG);
if (reg < 0)
return reg;
if (val == 0 && val2 == 0) {
reg |= MMA8452_TRANSIENT_CFG_HPF_BYP;
} else {
reg &= ~MMA8452_TRANSIENT_CFG_HPF_BYP;
ret = mma8452_set_hp_filter_frequency(data, val, val2);
if (ret < 0)
return ret;
}
return mma8452_change_config(data, MMA8452_TRANSIENT_CFG, reg);
default:
return -EINVAL;
}
}
static int mma8452_read_event_config(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan,
enum iio_event_type type,
enum iio_event_direction dir)
{
struct mma8452_data *data = iio_priv(indio_dev);
const struct mma_chip_info *chip = data->chip_info;
int ret;
ret = i2c_smbus_read_byte_data(data->client,
data->chip_info->ev_cfg);
if (ret < 0)
return ret;
return !!(ret & BIT(chan->scan_index + chip->ev_cfg_chan_shift));
}
static int mma8452_write_event_config(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan,
enum iio_event_type type,
enum iio_event_direction dir,
int state)
{
struct mma8452_data *data = iio_priv(indio_dev);
const struct mma_chip_info *chip = data->chip_info;
int val;
val = i2c_smbus_read_byte_data(data->client, chip->ev_cfg);
if (val < 0)
return val;
if (state)
val |= BIT(chan->scan_index + chip->ev_cfg_chan_shift);
else
val &= ~BIT(chan->scan_index + chip->ev_cfg_chan_shift);
val |= chip->ev_cfg_ele;
val |= MMA8452_FF_MT_CFG_OAE;
return mma8452_change_config(data, chip->ev_cfg, val);
}
static void mma8452_transient_interrupt(struct iio_dev *indio_dev)
{
struct mma8452_data *data = iio_priv(indio_dev);
s64 ts = iio_get_time_ns();
int src;
src = i2c_smbus_read_byte_data(data->client, data->chip_info->ev_src);
if (src < 0)
return;
if (src & data->chip_info->ev_src_xe)
iio_push_event(indio_dev,
IIO_MOD_EVENT_CODE(IIO_ACCEL, 0, IIO_MOD_X,
IIO_EV_TYPE_MAG,
IIO_EV_DIR_RISING),
ts);
if (src & data->chip_info->ev_src_ye)
iio_push_event(indio_dev,
IIO_MOD_EVENT_CODE(IIO_ACCEL, 0, IIO_MOD_Y,
IIO_EV_TYPE_MAG,
IIO_EV_DIR_RISING),
ts);
if (src & data->chip_info->ev_src_ze)
iio_push_event(indio_dev,
IIO_MOD_EVENT_CODE(IIO_ACCEL, 0, IIO_MOD_Z,
IIO_EV_TYPE_MAG,
IIO_EV_DIR_RISING),
ts);
}
static irqreturn_t mma8452_interrupt(int irq, void *p)
{
struct iio_dev *indio_dev = p;
struct mma8452_data *data = iio_priv(indio_dev);
const struct mma_chip_info *chip = data->chip_info;
int ret = IRQ_NONE;
int src;
src = i2c_smbus_read_byte_data(data->client, MMA8452_INT_SRC);
if (src < 0)
return IRQ_NONE;
if (src & MMA8452_INT_DRDY) {
iio_trigger_poll_chained(indio_dev->trig);
ret = IRQ_HANDLED;
}
if ((src & MMA8452_INT_TRANS &&
chip->ev_src == MMA8452_TRANSIENT_SRC) ||
(src & MMA8452_INT_FF_MT &&
chip->ev_src == MMA8452_FF_MT_SRC)) {
mma8452_transient_interrupt(indio_dev);
ret = IRQ_HANDLED;
}
return ret;
}
static irqreturn_t mma8452_trigger_handler(int irq, void *p)
{
struct iio_poll_func *pf = p;
struct iio_dev *indio_dev = pf->indio_dev;
struct mma8452_data *data = iio_priv(indio_dev);
u8 buffer[16]; /* 3 16-bit channels + padding + ts */
int ret;
ret = mma8452_read(data, (__be16 *)buffer);
if (ret < 0)
goto done;
iio_push_to_buffers_with_timestamp(indio_dev, buffer,
iio_get_time_ns());
done:
iio_trigger_notify_done(indio_dev->trig);
return IRQ_HANDLED;
}
static int mma8452_reg_access_dbg(struct iio_dev *indio_dev,
unsigned reg, unsigned writeval,
unsigned *readval)
{
int ret;
struct mma8452_data *data = iio_priv(indio_dev);
if (reg > MMA8452_MAX_REG)
return -EINVAL;
if (!readval)
return mma8452_change_config(data, reg, writeval);
ret = i2c_smbus_read_byte_data(data->client, reg);
if (ret < 0)
return ret;
*readval = ret;
return 0;
}
static const struct iio_event_spec mma8452_transient_event[] = {
{
.type = IIO_EV_TYPE_MAG,
.dir = IIO_EV_DIR_RISING,
.mask_separate = BIT(IIO_EV_INFO_ENABLE),
.mask_shared_by_type = BIT(IIO_EV_INFO_VALUE) |
BIT(IIO_EV_INFO_PERIOD) |
BIT(IIO_EV_INFO_HIGH_PASS_FILTER_3DB)
},
};
static const struct iio_event_spec mma8452_motion_event[] = {
{
.type = IIO_EV_TYPE_MAG,
.dir = IIO_EV_DIR_RISING,
.mask_separate = BIT(IIO_EV_INFO_ENABLE),
.mask_shared_by_type = BIT(IIO_EV_INFO_VALUE) |
BIT(IIO_EV_INFO_PERIOD)
},
};
/*
* Threshold is configured in fixed 8G/127 steps regardless of
* currently selected scale for measurement.
*/
static IIO_CONST_ATTR_NAMED(accel_transient_scale, in_accel_scale, "0.617742");
static struct attribute *mma8452_event_attributes[] = {
&iio_const_attr_accel_transient_scale.dev_attr.attr,
NULL,
};
static struct attribute_group mma8452_event_attribute_group = {
.attrs = mma8452_event_attributes,
.name = "events",
};
#define MMA8452_CHANNEL(axis, idx, bits) { \
.type = IIO_ACCEL, \
.modified = 1, \
.channel2 = IIO_MOD_##axis, \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
BIT(IIO_CHAN_INFO_CALIBBIAS), \
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ) | \
BIT(IIO_CHAN_INFO_SCALE) | \
BIT(IIO_CHAN_INFO_HIGH_PASS_FILTER_3DB_FREQUENCY), \
.scan_index = idx, \
.scan_type = { \
.sign = 's', \
.realbits = (bits), \
.storagebits = 16, \
.shift = 16 - (bits), \
.endianness = IIO_BE, \
}, \
.event_spec = mma8452_transient_event, \
.num_event_specs = ARRAY_SIZE(mma8452_transient_event), \
}
static const struct iio_chan_spec mma8452_channels[] = {
MMA8452_CHANNEL(X, 0, 12),
MMA8452_CHANNEL(Y, 1, 12),
MMA8452_CHANNEL(Z, 2, 12),
IIO_CHAN_SOFT_TIMESTAMP(3),
};
static const struct iio_chan_spec mma8453_channels[] = {
MMA8452_CHANNEL(X, 0, 10),
MMA8452_CHANNEL(Y, 1, 10),
MMA8452_CHANNEL(Z, 2, 10),
IIO_CHAN_SOFT_TIMESTAMP(3),
};
enum {
mma8452,
mma8453,
};
static const struct mma_chip_info mma_chip_info_table[] = {
[mma8452] = {
.chip_id = MMA8452_DEVICE_ID,
.channels = mma8452_channels,
.num_channels = ARRAY_SIZE(mma8452_channels),
/*
* Hardware has fullscale of -2G, -4G, -8G corresponding to
* raw value -2048 for 12 bit or -512 for 10 bit.
* The userspace interface uses m/s^2 and we declare micro units
* So scale factor for 12 bit here is given by:
* g * N * 1000000 / 2048 for N = 2, 4, 8 and g=9.80665
*/
.mma_scales = { {0, 9577}, {0, 19154}, {0, 38307} },
.ev_cfg = MMA8452_TRANSIENT_CFG,
.ev_cfg_ele = MMA8452_TRANSIENT_CFG_ELE,
.ev_cfg_chan_shift = 1,
.ev_src = MMA8452_TRANSIENT_SRC,
.ev_src_xe = MMA8452_TRANSIENT_SRC_XTRANSE,
.ev_src_ye = MMA8452_TRANSIENT_SRC_YTRANSE,
.ev_src_ze = MMA8452_TRANSIENT_SRC_ZTRANSE,
.ev_ths = MMA8452_TRANSIENT_THS,
.ev_ths_mask = MMA8452_TRANSIENT_THS_MASK,
.ev_count = MMA8452_TRANSIENT_COUNT,
},
[mma8453] = {
.chip_id = MMA8453_DEVICE_ID,
.channels = mma8453_channels,
.num_channels = ARRAY_SIZE(mma8453_channels),
.mma_scales = { {0, 38307}, {0, 76614}, {0, 153228} },
.ev_cfg = MMA8452_TRANSIENT_CFG,
.ev_cfg_ele = MMA8452_TRANSIENT_CFG_ELE,
.ev_cfg_chan_shift = 1,
.ev_src = MMA8452_TRANSIENT_SRC,
.ev_src_xe = MMA8452_TRANSIENT_SRC_XTRANSE,
.ev_src_ye = MMA8452_TRANSIENT_SRC_YTRANSE,
.ev_src_ze = MMA8452_TRANSIENT_SRC_ZTRANSE,
.ev_ths = MMA8452_TRANSIENT_THS,
.ev_ths_mask = MMA8452_TRANSIENT_THS_MASK,
.ev_count = MMA8452_TRANSIENT_COUNT,
},
};
static struct attribute *mma8452_attributes[] = {
&iio_dev_attr_sampling_frequency_available.dev_attr.attr,
&iio_dev_attr_in_accel_scale_available.dev_attr.attr,
&iio_dev_attr_in_accel_filter_high_pass_3db_frequency_available.dev_attr.attr,
NULL
};
static const struct attribute_group mma8452_group = {
.attrs = mma8452_attributes,
};
static const struct iio_info mma8452_info = {
.attrs = &mma8452_group,
.read_raw = &mma8452_read_raw,
.write_raw = &mma8452_write_raw,
.event_attrs = &mma8452_event_attribute_group,
.read_event_value = &mma8452_read_thresh,
.write_event_value = &mma8452_write_thresh,
.read_event_config = &mma8452_read_event_config,
.write_event_config = &mma8452_write_event_config,
.debugfs_reg_access = &mma8452_reg_access_dbg,
.driver_module = THIS_MODULE,
};
static const unsigned long mma8452_scan_masks[] = {0x7, 0};
static int mma8452_data_rdy_trigger_set_state(struct iio_trigger *trig,
bool state)
{
struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
struct mma8452_data *data = iio_priv(indio_dev);
int reg;
reg = i2c_smbus_read_byte_data(data->client, MMA8452_CTRL_REG4);
if (reg < 0)
return reg;
if (state)
reg |= MMA8452_INT_DRDY;
else
reg &= ~MMA8452_INT_DRDY;
return mma8452_change_config(data, MMA8452_CTRL_REG4, reg);
}
static int mma8452_validate_device(struct iio_trigger *trig,
struct iio_dev *indio_dev)
{
struct iio_dev *indio = iio_trigger_get_drvdata(trig);
if (indio != indio_dev)
return -EINVAL;
return 0;
}
static const struct iio_trigger_ops mma8452_trigger_ops = {
.set_trigger_state = mma8452_data_rdy_trigger_set_state,
.validate_device = mma8452_validate_device,
.owner = THIS_MODULE,
};
static int mma8452_trigger_setup(struct iio_dev *indio_dev)
{
struct mma8452_data *data = iio_priv(indio_dev);
struct iio_trigger *trig;
int ret;
trig = devm_iio_trigger_alloc(&data->client->dev, "%s-dev%d",
indio_dev->name,
indio_dev->id);
if (!trig)
return -ENOMEM;
trig->dev.parent = &data->client->dev;
trig->ops = &mma8452_trigger_ops;
iio_trigger_set_drvdata(trig, indio_dev);
ret = iio_trigger_register(trig);
if (ret)
return ret;
indio_dev->trig = trig;
return 0;
}
static void mma8452_trigger_cleanup(struct iio_dev *indio_dev)
{
if (indio_dev->trig)
iio_trigger_unregister(indio_dev->trig);
}
static int mma8452_reset(struct i2c_client *client)
{
int i;
int ret;
ret = i2c_smbus_write_byte_data(client, MMA8452_CTRL_REG2,
MMA8452_CTRL_REG2_RST);
if (ret < 0)
return ret;
for (i = 0; i < 10; i++) {
usleep_range(100, 200);
ret = i2c_smbus_read_byte_data(client, MMA8452_CTRL_REG2);
if (ret == -EIO)
continue; /* I2C comm reset */
if (ret < 0)
return ret;
if (!(ret & MMA8452_CTRL_REG2_RST))
return 0;
}
return -ETIMEDOUT;
}
static const struct of_device_id mma8452_dt_ids[] = {
{ .compatible = "fsl,mma8452", .data = &mma_chip_info_table[mma8452] },
{ .compatible = "fsl,mma8453", .data = &mma_chip_info_table[mma8453] },
{ }
};
MODULE_DEVICE_TABLE(of, mma8452_dt_ids);
static int mma8452_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct mma8452_data *data;
struct iio_dev *indio_dev;
int ret;
const struct of_device_id *match;
ret = i2c_smbus_read_byte_data(client, MMA8452_WHO_AM_I);
if (ret < 0)
return ret;
if (ret != MMA8452_DEVICE_ID && ret != MMA8453_DEVICE_ID)
return -ENODEV;
match = of_match_device(mma8452_dt_ids, &client->dev);
if (!match) {
dev_err(&client->dev, "unknown device model\n");
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);
data->chip_info = match->data;
dev_info(&client->dev, "registering %s accelerometer; ID 0x%x\n",
match->compatible, data->chip_info->chip_id);
i2c_set_clientdata(client, indio_dev);
indio_dev->info = &mma8452_info;
indio_dev->name = id->name;
indio_dev->dev.parent = &client->dev;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->channels = data->chip_info->channels;
indio_dev->num_channels = data->chip_info->num_channels;
indio_dev->available_scan_masks = mma8452_scan_masks;
ret = mma8452_reset(client);
if (ret < 0)
return ret;
data->data_cfg = MMA8452_DATA_CFG_FS_2G;
ret = i2c_smbus_write_byte_data(client, MMA8452_DATA_CFG,
data->data_cfg);
if (ret < 0)
return ret;
/*
* By default set transient threshold to max to avoid events if
* enabling without configuring threshold.
*/
ret = i2c_smbus_write_byte_data(client, MMA8452_TRANSIENT_THS,
MMA8452_TRANSIENT_THS_MASK);
if (ret < 0)
return ret;
if (client->irq) {
/*
* Although we enable the interrupt sources once and for
* all here the event detection itself is not enabled until
* userspace asks for it by mma8452_write_event_config()
*/
int supported_interrupts = MMA8452_INT_DRDY |
MMA8452_INT_TRANS |
MMA8452_INT_FF_MT;
int enabled_interrupts = MMA8452_INT_TRANS |
MMA8452_INT_FF_MT;
/* Assume wired to INT1 pin */
ret = i2c_smbus_write_byte_data(client,
MMA8452_CTRL_REG5,
supported_interrupts);
if (ret < 0)
return ret;
ret = i2c_smbus_write_byte_data(client,
MMA8452_CTRL_REG4,
enabled_interrupts);
if (ret < 0)
return ret;
ret = mma8452_trigger_setup(indio_dev);
if (ret < 0)
return ret;
}
data->ctrl_reg1 = MMA8452_CTRL_ACTIVE |
(MMA8452_CTRL_DR_DEFAULT << MMA8452_CTRL_DR_SHIFT);
ret = i2c_smbus_write_byte_data(client, MMA8452_CTRL_REG1,
data->ctrl_reg1);
if (ret < 0)
goto trigger_cleanup;
ret = iio_triggered_buffer_setup(indio_dev, NULL,
mma8452_trigger_handler, NULL);
if (ret < 0)
goto trigger_cleanup;
if (client->irq) {
ret = devm_request_threaded_irq(&client->dev,
client->irq,
NULL, mma8452_interrupt,
IRQF_TRIGGER_LOW | IRQF_ONESHOT,
client->name, indio_dev);
if (ret)
goto buffer_cleanup;
}
ret = iio_device_register(indio_dev);
if (ret < 0)
goto buffer_cleanup;
return 0;
buffer_cleanup:
iio_triggered_buffer_cleanup(indio_dev);
trigger_cleanup:
mma8452_trigger_cleanup(indio_dev);
return ret;
}
static int mma8452_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);
mma8452_trigger_cleanup(indio_dev);
mma8452_standby(iio_priv(indio_dev));
return 0;
}
#ifdef CONFIG_PM_SLEEP
static int mma8452_suspend(struct device *dev)
{
return mma8452_standby(iio_priv(i2c_get_clientdata(
to_i2c_client(dev))));
}
static int mma8452_resume(struct device *dev)
{
return mma8452_active(iio_priv(i2c_get_clientdata(
to_i2c_client(dev))));
}
static SIMPLE_DEV_PM_OPS(mma8452_pm_ops, mma8452_suspend, mma8452_resume);
#define MMA8452_PM_OPS (&mma8452_pm_ops)
#else
#define MMA8452_PM_OPS NULL
#endif
static const struct i2c_device_id mma8452_id[] = {
{ "mma8452", mma8452 },
{ "mma8453", mma8453 },
{ }
};
MODULE_DEVICE_TABLE(i2c, mma8452_id);
static struct i2c_driver mma8452_driver = {
.driver = {
.name = "mma8452",
.of_match_table = of_match_ptr(mma8452_dt_ids),
.pm = MMA8452_PM_OPS,
},
.probe = mma8452_probe,
.remove = mma8452_remove,
.id_table = mma8452_id,
};
module_i2c_driver(mma8452_driver);
MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
MODULE_DESCRIPTION("Freescale MMA8452 accelerometer driver");
MODULE_LICENSE("GPL");
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