On Thu, 20 Feb 2025 10:42:25 +0000
Lothar Rubusch <l.rubusch@xxxxxxxxx> wrote:
> Add the single tap feature with a threshold in 62.5mg/LSB points and a
> scaled duration in us. Keep singletap threshold in regmap cache but
> the scaled value of duration in us as member variable.
>
> Both use IIO channels for individual enable of the x/y/z axis. Initializes
> threshold and duration with reasonable content. When an interrupt is
> caught it will be pushed to the according IIO channel.
>
> Signed-off-by: Lothar Rubusch <l.rubusch@xxxxxxxxx>
> ---
> drivers/iio/accel/adxl345_core.c | 364 ++++++++++++++++++++++++++++++-
> 1 file changed, 362 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/iio/accel/adxl345_core.c b/drivers/iio/accel/adxl345_core.c
> index 0cee81bc1877..d05593c0d513 100644
> --- a/drivers/iio/accel/adxl345_core.c
> +++ b/drivers/iio/accel/adxl345_core.c
> @@ -8,6 +8,7 @@
> */
>
> #include <linux/bitfield.h>
> +#include <linux/bitops.h>
> #include <linux/interrupt.h>
> #include <linux/module.h>
> #include <linux/property.h>
> @@ -17,6 +18,7 @@
> #include <linux/iio/iio.h>
> #include <linux/iio/sysfs.h>
> #include <linux/iio/buffer.h>
> +#include <linux/iio/events.h>
> #include <linux/iio/kfifo_buf.h>
>
> #include "adxl345.h"
> @@ -31,6 +33,33 @@
> #define ADXL345_INT1 0
> #define ADXL345_INT2 1
>
> +#define ADXL345_REG_TAP_AXIS_MSK GENMASK(2, 0)
This is a bit confusing. Here we have a mask for axis that
has 3 bits.
> +
> +enum adxl345_axis {
> + ADXL345_Z_EN = BIT(0),
> + ADXL345_Y_EN = BIT(1),
> + ADXL345_X_EN = BIT(2),
> + /* Suppress double tap detection if value > tap threshold */
> + ADXL345_TAP_SUPPRESS = BIT(3),
and here an enum that is closely related with 4.
> +};
...
> enum adxl345_chans {
> @@ -83,6 +128,7 @@ bool adxl345_is_volatile_reg(struct device *dev, unsigned int reg)
> case ADXL345_REG_DATA_AXIS(3):
> case ADXL345_REG_DATA_AXIS(4):
> case ADXL345_REG_DATA_AXIS(5):
> + case ADXL345_REG_ACT_TAP_STATUS:
ah. I thought this had a full list from earlier patches.
Move this and any later additions back to patch 4.
> case ADXL345_REG_FIFO_STATUS:
> case ADXL345_REG_INT_SOURCE:
> return true;
> @@ -112,6 +158,117 @@ static int adxl345_set_measure_en(struct adxl345_state *st, bool en)
> return regmap_write(st->regmap, ADXL345_REG_POWER_CTL, val);
> }
>
> +/* tap */
> +
> +static int adxl345_write_tap_axis(struct adxl345_state *st,
> + enum adxl345_axis axis, bool en)
> +{
> + st->tap_axis_ctrl = FIELD_GET(ADXL345_REG_TAP_AXIS_MSK,
> + en ? st->tap_axis_ctrl | axis
> + : st->tap_axis_ctrl & ~axis);
> +
> + return regmap_update_bits(st->regmap, ADXL345_REG_TAP_AXIS,
> + ADXL345_REG_TAP_AXIS_MSK,
> + FIELD_PREP(ADXL345_REG_TAP_AXIS_MSK,
> + st->tap_axis_ctrl));
Given that mask is bottom few bits anyway and you can just define the
tap axis as separate fields.
See below, but I would push the IIO_MOD values down into here. Put the switch
per axis in at this level and then use a simple if statement to
call regmap_clear_bits() / regmap_set_bits() based on enable.
> +}
...
> +static int adxl345_is_tap_en(struct adxl345_state *st,
> + enum adxl345_tap_type type, bool *en)
> +{
> + int ret;
> + unsigned int regval;
> +
> + ret = regmap_read(st->regmap, ADXL345_REG_INT_ENABLE, ®val);
> + if (ret)
> + return ret;
> +
> + *en = (adxl345_tap_int_reg[type] & regval) > 0;
Could use 0/1 return rather than passing a paramter for the output.
I don't mind much either way.
> +
> + return 0;
> +}
> +
> +static int adxl345_set_singletap_en(struct adxl345_state *st,
I'd push the IIO modifier in here instead of axis.
> + enum adxl345_axis axis, bool en)
> +{
> + int ret;
> +
> + ret = adxl345_write_tap_axis(st, axis, en);
And push it into here as well.
> + if (ret)
> + return ret;
> +
> + return _adxl345_set_tap_int(st, ADXL345_SINGLE_TAP, en);
> +}
> +
...
> @@ -197,6 +354,160 @@ static int adxl345_write_raw(struct iio_dev *indio_dev,
> return -EINVAL;
> }
>
> +static int adxl345_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 adxl345_state *st = iio_priv(indio_dev);
> + bool int_en;
> + bool axis_en;
> + int ret = -EFAULT;
> +
> + switch (type) {
> + case IIO_EV_TYPE_GESTURE:
> + switch (chan->channel2) {
> + case IIO_MOD_X:
> + axis_en = FIELD_GET(ADXL345_X_EN, st->tap_axis_ctrl);
> + break;
> + case IIO_MOD_Y:
> + axis_en = FIELD_GET(ADXL345_Y_EN, st->tap_axis_ctrl);
> + break;
> + case IIO_MOD_Z:
> + axis_en = FIELD_GET(ADXL345_Z_EN, st->tap_axis_ctrl);
> + break;
> + default:
> + axis_en = ADXL345_TAP_SUPPRESS;
> + break;
> + }
I'd check axis_en here.
if (!axis_en)
return false;
> +
> + switch (dir) {
> + case IIO_EV_DIR_SINGLETAP:
> + ret = adxl345_is_tap_en(st, ADXL345_SINGLE_TAP, &int_en);
> + if (ret)
> + return ret;
> + return int_en && axis_en;
Then this just becomes return int_en;
> + default:
> + return -EINVAL;
> + }
> + default:
> + return -EINVAL;
> + }
> +}
> +
> +static int adxl345_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 adxl345_state *st = iio_priv(indio_dev);
> + enum adxl345_axis axis;
> +
> + switch (type) {
> + case IIO_EV_TYPE_GESTURE:
> + switch (chan->channel2) {
> + case IIO_MOD_X:
> + axis = ADXL345_X_EN;
> + break;
> + case IIO_MOD_Y:
> + axis = ADXL345_Y_EN;
> + break;
> + case IIO_MOD_Z:
> + axis = ADXL345_Z_EN;
> + break;
> + default:
> + axis = ADXL345_TAP_SUPPRESS;
How are we getting another axis here?
> + break;
> + }
> +
> + switch (dir) {
> + case IIO_EV_DIR_SINGLETAP:
> + return adxl345_set_singletap_en(st, axis, state);
As above, pass chan->channel2 into here so we can simplify the eventual
setting of the the register values.
> + default:
> + return -EINVAL;
> + }
> + default:
> + return -EINVAL;
> + }
> +}
> +
> +static int adxl345_read_event_value(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 adxl345_state *st = iio_priv(indio_dev);
> + unsigned int tap_threshold;
> + int ret;
> +
> + switch (type) {
> + case IIO_EV_TYPE_GESTURE:
> + switch (info) {
> + case IIO_EV_INFO_VALUE:
> + /*
> + * The scale factor is 62.5mg/LSB (i.e. 0xFF = 16g) but
> + * not applied here.
Maybe say why.
> + */
> + ret = regmap_read(st->regmap, ADXL345_REG_THRESH_TAP, &tap_threshold);
Bit of a long line. Aim for sub 80 chars unless readability is greatly
hurt.
> + if (ret)
> + return ret;
> + *val = sign_extend32(tap_threshold, 7);
> + return IIO_VAL_INT;
> + case IIO_EV_INFO_TIMEOUT:
> + *val = st->tap_duration_us;
> + *val2 = 1000000;
> + return IIO_VAL_FRACTIONAL;
> + default:
> + return -EINVAL;
> + }
> + default:
> + return -EINVAL;
> + }
> +}
...
