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iio:magnetometer:ak8975: triggered buffer support 

This will be used together with an external trigger (e.g hrtimer based
software trigger).

Signed-off-by: Gregor Boirie <gregor.boirie@parrot.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
This commit is contained in:
Gregor Boirie 2016-04-08 17:09:08 +02:00 committed by Jonathan Cameron
parent fbbc5e7044
commit bc11ca4a0b
2 changed files with 112 additions and 25 deletions
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2
drivers/iio/magnetometer/Kconfig
View File

@ -9,6 +9,8 @@ config AK8975
tristate "Asahi Kasei AK 3-Axis Magnetometer"
depends on I2C
depends on GPIOLIB || COMPILE_TEST
select IIO_BUFFER
select IIO_TRIGGERED_BUFFER
help
Say yes here to build support for Asahi Kasei AK8975, AK8963,
AK09911 or AK09912 3-Axis Magnetometer.

135
drivers/iio/magnetometer/ak8975.c
View File

@ -36,6 +36,12 @@
#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/regulator/consumer.h>
/*
* Register definitions, as well as various shifts and masks to get at the
* individual fields of the registers.
@ -633,22 +639,15 @@ static int wait_conversion_complete_interrupt(struct ak8975_data *data)
return ret > 0 ? 0 : -ETIME;
}
/*
* Emits the raw flux value for the x, y, or z axis.
*/
static int ak8975_read_axis(struct iio_dev *indio_dev, int index, int *val)
static int ak8975_start_read_axis(struct ak8975_data *data,
const struct i2c_client *client)
{
struct ak8975_data *data = iio_priv(indio_dev);
struct i2c_client *client = data->client;
int ret;
mutex_lock(&data->lock);
/* Set up the device for taking a sample. */
ret = ak8975_set_mode(data, MODE_ONCE);
int ret = ak8975_set_mode(data, MODE_ONCE);
if (ret < 0) {
dev_err(&client->dev, "Error in setting operating mode\n");
goto exit;
return ret;
}
/* Wait for the conversion to complete. */
@ -659,7 +658,7 @@ static int ak8975_read_axis(struct iio_dev *indio_dev, int index, int *val)
else
ret = wait_conversion_complete_polled(data);
if (ret < 0)
goto exit;
return ret;
/* This will be executed only for non-interrupt based waiting case */
if (ret & data->def->ctrl_masks[ST1_DRDY]) {
@ -667,32 +666,45 @@ static int ak8975_read_axis(struct iio_dev *indio_dev, int index, int *val)
data->def->ctrl_regs[ST2]);
if (ret < 0) {
dev_err(&client->dev, "Error in reading ST2\n");
goto exit;
return ret;
}
if (ret & (data->def->ctrl_masks[ST2_DERR] |
data->def->ctrl_masks[ST2_HOFL])) {
dev_err(&client->dev, "ST2 status error 0x%x\n", ret);
ret = -EINVAL;
goto exit;
return -EINVAL;
}
}
/* Read the flux value from the appropriate register
(the register is specified in the iio device attributes). */
ret = i2c_smbus_read_word_data(client, data->def->data_regs[index]);
if (ret < 0) {
dev_err(&client->dev, "Read axis data fails\n");
return 0;
}
/* Retrieve raw flux value for one of the x, y, or z axis. */
static int ak8975_read_axis(struct iio_dev *indio_dev, int index, int *val)
{
struct ak8975_data *data = iio_priv(indio_dev);
const struct i2c_client *client = data->client;
const struct ak_def *def = data->def;
int ret;
mutex_lock(&data->lock);
ret = ak8975_start_read_axis(data, client);
if (ret)
goto exit;
ret = i2c_smbus_read_word_data(client, def->data_regs[index]);
if (ret < 0)
goto exit;
}
mutex_unlock(&data->lock);
/* Clamp to valid range. */
*val = clamp_t(s16, ret, -data->def->range, data->def->range);
*val = clamp_t(s16, ret, -def->range, def->range);
return IIO_VAL_INT;
exit:
mutex_unlock(&data->lock);
dev_err(&client->dev, "Error in reading axis\n");
return ret;
}
@ -722,12 +734,22 @@ static int ak8975_read_raw(struct iio_dev *indio_dev,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
BIT(IIO_CHAN_INFO_SCALE), \
.address = index, \
.scan_index = index, \
.scan_type = { \
.sign = 's', \
.realbits = 16, \
.storagebits = 16, \
.endianness = IIO_CPU \
} \
}
static const struct iio_chan_spec ak8975_channels[] = {
AK8975_CHANNEL(X, 0), AK8975_CHANNEL(Y, 1), AK8975_CHANNEL(Z, 2),
IIO_CHAN_SOFT_TIMESTAMP(3),
};
static const unsigned long ak8975_scan_masks[] = { 0x7, 0 };
static const struct iio_info ak8975_info = {
.read_raw = &ak8975_read_raw,
.driver_module = THIS_MODULE,
@ -756,6 +778,56 @@ static const char *ak8975_match_acpi_device(struct device *dev,
return dev_name(dev);
}
static void ak8975_fill_buffer(struct iio_dev *indio_dev)
{
struct ak8975_data *data = iio_priv(indio_dev);
const struct i2c_client *client = data->client;
const struct ak_def *def = data->def;
int ret;
s16 buff[8]; /* 3 x 16 bits axis values + 1 aligned 64 bits timestamp */
mutex_lock(&data->lock);
ret = ak8975_start_read_axis(data, client);
if (ret)
goto unlock;
/*
* For each axis, read the flux value from the appropriate register
* (the register is specified in the iio device attributes).
*/
ret = i2c_smbus_read_i2c_block_data_or_emulated(client,
def->data_regs[0],
3 * sizeof(buff[0]),
(u8 *)buff);
if (ret < 0)
goto unlock;
mutex_unlock(&data->lock);
/* Clamp to valid range. */
buff[0] = clamp_t(s16, le16_to_cpu(buff[0]), -def->range, def->range);
buff[1] = clamp_t(s16, le16_to_cpu(buff[1]), -def->range, def->range);
buff[2] = clamp_t(s16, le16_to_cpu(buff[2]), -def->range, def->range);
iio_push_to_buffers_with_timestamp(indio_dev, buff, iio_get_time_ns());
return;
unlock:
mutex_unlock(&data->lock);
dev_err(&client->dev, "Error in reading axes block\n");
}
static irqreturn_t ak8975_handle_trigger(int irq, void *p)
{
const struct iio_poll_func *pf = p;
struct iio_dev *indio_dev = pf->indio_dev;
ak8975_fill_buffer(indio_dev);
iio_trigger_notify_done(indio_dev->trig);
return IRQ_HANDLED;
}
static int ak8975_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
@ -845,15 +917,27 @@ static int ak8975_probe(struct i2c_client *client,
indio_dev->channels = ak8975_channels;
indio_dev->num_channels = ARRAY_SIZE(ak8975_channels);
indio_dev->info = &ak8975_info;
indio_dev->available_scan_masks = ak8975_scan_masks;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->name = name;
err = iio_device_register(indio_dev);
if (err)
err = iio_triggered_buffer_setup(indio_dev, NULL, ak8975_handle_trigger,
NULL);
if (err) {
dev_err(&client->dev, "triggered buffer setup failed\n");
goto power_off;
}
err = iio_device_register(indio_dev);
if (err) {
dev_err(&client->dev, "device register failed\n");
goto cleanup_buffer;
}
return 0;
cleanup_buffer:
iio_triggered_buffer_cleanup(indio_dev);
power_off:
ak8975_power_off(client);
return err;
@ -864,6 +948,7 @@ static int ak8975_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);
ak8975_power_off(client);
return 0;