On 01/09/16 10:44, Linus Walleij wrote:
> As is custom with all modern sensors, add a clever burst mode
> that will just stream out values from the sensor and provide it
> to userspace to do the proper offsetting and scaling.
>
> This is the result when tested with an HRTimer trigger:
>
> $ generic_buffer -a -c 10 -n kxsd9 -t foo
> /sys/bus/iio/devices/iio:device1 foo
> 0.371318 0.718680 9.869872 1795.000000 97545896129
> -0.586922 0.179670 9.378775 2398.000000 97555864721
> -0.299450 0.179670 10.348992 2672.000000 97565874055
> 0.371318 0.335384 11.103606 2816.000000 97575883240
> 0.179670 0.574944 10.540640 2847.000000 97585862351
> 0.335384 0.754614 9.953718 2840.000000 97595872425
> 0.179670 0.754614 10.732288 2879.000000 97605882351
> 0.000000 0.754614 10.348992 2872.000000 97615891832
> -0.730658 0.574944 9.570422 2831.000000 97625871536
> 0.000000 1.137910 10.732288 2872.000000 97635881610
>
> Columns shown are x, y, z acceleration, so a positive acceleration
> of ~9.81 (shaky due to bad calibration) along the z axis. The
> fourth column is the AUX IN which is floating on this system,
> it seems to float up to the 2.85V VDD voltage.
>
> To be able to cleanup the triggered buffer, we need to add .remove()
> callbacks to the I2C and SPI subdrivers and call back into an
> exported .remove() callback in the core.
>
> Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
Tested-by: Jonathan Cameron <jic23@xxxxxxxxxx>
I'd forgotten how bad the accuracy on accelerometers is sometimes!
Jonathan
> ---
> ChangeLog v1->v2:
> - Rebased on the common remove function already present in
> the new base of the series.
> ---
> drivers/iio/accel/Kconfig | 2 ++
> drivers/iio/accel/kxsd9.c | 82 +++++++++++++++++++++++++++++++++++++++++++----
> 2 files changed, 78 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig
> index ab1c87ce07ed..cd69353989cf 100644
> --- a/drivers/iio/accel/Kconfig
> +++ b/drivers/iio/accel/Kconfig
> @@ -96,6 +96,8 @@ config IIO_ST_ACCEL_SPI_3AXIS
>
> config KXSD9
> tristate "Kionix KXSD9 Accelerometer Driver"
> + select IIO_BUFFER
> + select IIO_TRIGGERED_BUFFER
> help
> Say yes here to build support for the Kionix KXSD9 accelerometer.
> It can be accessed using an (optional) SPI or I2C interface.
> diff --git a/drivers/iio/accel/kxsd9.c b/drivers/iio/accel/kxsd9.c
> index 6a1e67723d0c..d84413ae14b1 100644
> --- a/drivers/iio/accel/kxsd9.c
> +++ b/drivers/iio/accel/kxsd9.c
> @@ -12,8 +12,6 @@
> * I have a suitable wire made up.
> *
> * TODO: Support the motion detector
> - * Uses register address incrementing so could have a
> - * heavily optimized ring buffer access function.
> */
>
> #include <linux/device.h>
> @@ -24,6 +22,9 @@
> #include <linux/regmap.h>
> #include <linux/iio/iio.h>
> #include <linux/iio/sysfs.h>
> +#include <linux/iio/buffer.h>
> +#include <linux/iio/triggered_buffer.h>
> +#include <linux/iio/trigger_consumer.h>
>
> #include "kxsd9.h"
>
> @@ -41,9 +42,11 @@
>
> /**
> * struct kxsd9_state - device related storage
> + * @dev: pointer to the parent device
> * @map: regmap to the device
> */
> struct kxsd9_state {
> + struct device *dev;
> struct regmap *map;
> };
>
> @@ -155,7 +158,35 @@ static int kxsd9_read_raw(struct iio_dev *indio_dev,
> error_ret:
> return ret;
> };
> -#define KXSD9_ACCEL_CHAN(axis) \
> +
> +static irqreturn_t kxsd9_trigger_handler(int irq, void *p)
> +{
> + const struct iio_poll_func *pf = p;
> + struct iio_dev *indio_dev = pf->indio_dev;
> + struct kxsd9_state *st = iio_priv(indio_dev);
> + int ret;
> + /* 4 * 16bit values AND timestamp */
> + __be16 hw_values[8];
> +
> + ret = regmap_bulk_read(st->map,
> + KXSD9_REG_X,
> + &hw_values,
> + 8);
> + if (ret) {
> + dev_err(st->dev,
> + "error reading data\n");
> + return ret;
> + }
> +
> + iio_push_to_buffers_with_timestamp(indio_dev,
> + hw_values,
> + iio_get_time_ns(indio_dev));
> + iio_trigger_notify_done(indio_dev->trig);
> +
> + return IRQ_HANDLED;
> +}
> +
> +#define KXSD9_ACCEL_CHAN(axis, index) \
> { \
> .type = IIO_ACCEL, \
> .modified = 1, \
> @@ -164,16 +195,35 @@ error_ret:
> .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \
> BIT(IIO_CHAN_INFO_OFFSET), \
> .address = KXSD9_REG_##axis, \
> + .scan_index = index, \
> + .scan_type = { \
> + .sign = 'u', \
> + .realbits = 12, \
> + .storagebits = 16, \
> + .shift = 4, \
> + .endianness = IIO_BE, \
> + }, \
> }
>
> static const struct iio_chan_spec kxsd9_channels[] = {
> - KXSD9_ACCEL_CHAN(X), KXSD9_ACCEL_CHAN(Y), KXSD9_ACCEL_CHAN(Z),
> + KXSD9_ACCEL_CHAN(X, 0),
> + KXSD9_ACCEL_CHAN(Y, 1),
> + KXSD9_ACCEL_CHAN(Z, 2),
> {
> .type = IIO_VOLTAGE,
> .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
> .indexed = 1,
> .address = KXSD9_REG_AUX,
> - }
> + .scan_index = 3,
> + .scan_type = {
> + .sign = 'u',
> + .realbits = 12,
> + .storagebits = 16,
> + .shift = 4,
> + .endianness = IIO_BE,
> + },
> + },
> + IIO_CHAN_SOFT_TIMESTAMP(4),
> };
>
> static const struct attribute_group kxsd9_attribute_group = {
> @@ -197,6 +247,9 @@ static const struct iio_info kxsd9_info = {
> .driver_module = THIS_MODULE,
> };
>
> +/* Four channels apart from timestamp, scan mask = 0x0f */
> +static const unsigned long kxsd9_scan_masks[] = { 0xf, 0 };
> +
> int kxsd9_common_probe(struct device *parent,
> struct regmap *map,
> const char *name)
> @@ -210,6 +263,7 @@ int kxsd9_common_probe(struct device *parent,
> return -ENOMEM;
>
> st = iio_priv(indio_dev);
> + st->dev = parent;
> st->map = map;
>
> indio_dev->channels = kxsd9_channels;
> @@ -218,16 +272,31 @@ int kxsd9_common_probe(struct device *parent,
> indio_dev->dev.parent = parent;
> indio_dev->info = &kxsd9_info;
> indio_dev->modes = INDIO_DIRECT_MODE;
> + indio_dev->available_scan_masks = kxsd9_scan_masks;
>
> kxsd9_power_up(st);
>
> + ret = iio_triggered_buffer_setup(indio_dev,
> + iio_pollfunc_store_time,
> + kxsd9_trigger_handler,
> + NULL);
> + if (ret) {
> + dev_err(parent, "triggered buffer setup failed\n");
> + return ret;
> + }
> +
> ret = iio_device_register(indio_dev);
> if (ret)
> - return ret;
> + goto err_cleanup_buffer;
>
> dev_set_drvdata(parent, indio_dev);
>
> return 0;
> +
> +err_cleanup_buffer:
> + iio_triggered_buffer_cleanup(indio_dev);
> +
> + return ret;
> }
> EXPORT_SYMBOL(kxsd9_common_probe);
>
> @@ -235,6 +304,7 @@ int kxsd9_common_remove(struct device *parent)
> {
> struct iio_dev *indio_dev = dev_get_drvdata(parent);
>
> + iio_triggered_buffer_cleanup(indio_dev);
> iio_device_unregister(indio_dev);
>
> return 0;
>
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