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iio: srf08: add triggered buffer support

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Add support for triggered buffers.

Data format is quite simple:
  distance     16 Bit
  alignment    48 Bit
  timestamp    64 Bit

Signed-off-by: Andreas Klinger <ak@it-klinger.de>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
This commit is contained in:
Andreas Klinger 2017-08-16 21:34:06 +02:00 committed by Jonathan Cameron
parent c02b3a113d
commit a831959371
1 changed files with 57 additions and 3 deletions
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60
drivers/iio/proximity/srf08.c
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@ -18,6 +18,9 @@
#include <linux/bitops.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/buffer.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/triggered_buffer.h>
/* registers of SRF08 device */
#define SRF08_WRITE_COMMAND 0x00 /* Command Register */
@ -35,9 +38,22 @@
struct srf08_data {
struct i2c_client *client;
int sensitivity; /* Gain */
int range_mm; /* max. Range in mm */
/*
* Gain in the datasheet is called sensitivity here to distinct it
* from the gain used with amplifiers of adc's
*/
int sensitivity;
/* max. Range in mm */
int range_mm;
struct mutex lock;
/*
* triggered buffer
* 1x16-bit channel + 3x16 padding + 4x16 timestamp
*/
s16 buffer[8];
};
/*
@ -110,6 +126,29 @@ static int srf08_read_ranging(struct srf08_data *data)
return ret;
}
static irqreturn_t srf08_trigger_handler(int irq, void *p)
{
struct iio_poll_func *pf = p;
struct iio_dev *indio_dev = pf->indio_dev;
struct srf08_data *data = iio_priv(indio_dev);
s16 sensor_data;
sensor_data = srf08_read_ranging(data);
if (sensor_data < 0)
goto err;
mutex_lock(&data->lock);
data->buffer[0] = sensor_data;
iio_push_to_buffers_with_timestamp(indio_dev,
data->buffer, pf->timestamp);
mutex_unlock(&data->lock);
err:
iio_trigger_notify_done(indio_dev->trig);
return IRQ_HANDLED;
}
static int srf08_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *channel, int *val,
int *val2, long mask)
@ -323,7 +362,15 @@ static const struct iio_chan_spec srf08_channels[] = {
.info_mask_separate =
BIT(IIO_CHAN_INFO_RAW) |
BIT(IIO_CHAN_INFO_SCALE),
.scan_index = 0,
.scan_type = {
.sign = 's',
.realbits = 16,
.storagebits = 16,
.endianness = IIO_CPU,
},
},
IIO_CHAN_SOFT_TIMESTAMP(1),
};
static const struct iio_info srf08_info = {
@ -362,6 +409,13 @@ static int srf08_probe(struct i2c_client *client,
mutex_init(&data->lock);
ret = devm_iio_triggered_buffer_setup(&client->dev, indio_dev,
iio_pollfunc_store_time, srf08_trigger_handler, NULL);
if (ret < 0) {
dev_err(&client->dev, "setup of iio triggered buffer failed\n");
return ret;
}
/*
* set default values of device here
* these register values cannot be read from the hardware
@ -402,5 +456,5 @@ static struct i2c_driver srf08_driver = {
module_i2c_driver(srf08_driver);
MODULE_AUTHOR("Andreas Klinger <ak@it-klinger.de>");
MODULE_DESCRIPTION("Devantech SRF08 ultrasonic ranger driver");
MODULE_DESCRIPTION("Devantech SRF08/SRF10 ultrasonic ranger driver");
MODULE_LICENSE("GPL");