2022-04-22 19:01:25

by Jagath Jog J

[permalink] [raw]
Subject: [PATCH v4 5/9] iio: accel: bma400: Add separate channel for step counter

Added channel for step counter which can be enable or disable
through the sysfs interface.

Signed-off-by: Jagath Jog J <[email protected]>
---
drivers/iio/accel/bma400.h | 2 +
drivers/iio/accel/bma400_core.c | 67 +++++++++++++++++++++++++++++++--
2 files changed, 65 insertions(+), 4 deletions(-)

diff --git a/drivers/iio/accel/bma400.h b/drivers/iio/accel/bma400.h
index 907e1a6c0a38..32c08f8b0b98 100644
--- a/drivers/iio/accel/bma400.h
+++ b/drivers/iio/accel/bma400.h
@@ -53,6 +53,8 @@
#define BMA400_STEP_CNT1_REG 0x16
#define BMA400_STEP_CNT3_REG 0x17
#define BMA400_STEP_STAT_REG 0x18
+#define BMA400_STEP_INT_MSK BIT(0)
+#define BMA400_STEP_RAW_LEN 0x03

/*
* Read-write configuration registers
diff --git a/drivers/iio/accel/bma400_core.c b/drivers/iio/accel/bma400_core.c
index 57910ccf9180..aafb5a40944d 100644
--- a/drivers/iio/accel/bma400_core.c
+++ b/drivers/iio/accel/bma400_core.c
@@ -19,6 +19,9 @@
#include <linux/mutex.h>
#include <linux/regmap.h>
#include <linux/regulator/consumer.h>
+#include <linux/slab.h>
+
+#include <asm/unaligned.h>

#include <linux/iio/iio.h>
#include <linux/iio/buffer.h>
@@ -67,6 +70,7 @@ struct bma400_data {
int oversampling_ratio;
int scale;
struct iio_trigger *trig;
+ int steps_enabled;
/* Correct time stamp alignment */
struct {
__le16 buff[3];
@@ -202,6 +206,12 @@ static const struct iio_chan_spec bma400_channels[] = {
.endianness = IIO_LE,
},
},
+ {
+ .type = IIO_STEPS,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
+ BIT(IIO_CHAN_INFO_ENABLE),
+ .scan_index = -1, /* No buffer support */
+ },
IIO_CHAN_SOFT_TIMESTAMP(4),
};

@@ -570,6 +580,38 @@ static int bma400_set_power_mode(struct bma400_data *data,
return 0;
}

+static int bma400_enable_steps(struct bma400_data *data, int val)
+{
+ int ret;
+
+ if (data->steps_enabled == val)
+ return 0;
+
+ ret = regmap_update_bits(data->regmap, BMA400_INT_CONFIG1_REG,
+ BMA400_STEP_INT_MSK,
+ FIELD_PREP(BMA400_STEP_INT_MSK, !!val));
+ data->steps_enabled = val;
+ return ret;
+}
+
+static int bma400_get_steps_reg(struct bma400_data *data, int *val)
+{
+ u8 *steps_raw;
+ int ret;
+
+ steps_raw = kmalloc(BMA400_STEP_RAW_LEN, GFP_KERNEL);
+ if (!steps_raw)
+ return -ENOMEM;
+
+ ret = regmap_bulk_read(data->regmap, BMA400_STEP_CNT0_REG,
+ steps_raw, BMA400_STEP_RAW_LEN);
+ if (ret)
+ return ret;
+ *val = get_unaligned_le24(steps_raw);
+ kfree(steps_raw);
+ return IIO_VAL_INT;
+}
+
static void bma400_init_tables(void)
{
int raw;
@@ -709,10 +751,17 @@ static int bma400_read_raw(struct iio_dev *indio_dev,

switch (mask) {
case IIO_CHAN_INFO_PROCESSED:
- mutex_lock(&data->mutex);
- ret = bma400_get_temp_reg(data, val, val2);
- mutex_unlock(&data->mutex);
- return ret;
+ switch (chan->type) {
+ case IIO_TEMP:
+ mutex_lock(&data->mutex);
+ ret = bma400_get_temp_reg(data, val, val2);
+ mutex_unlock(&data->mutex);
+ return ret;
+ case IIO_STEPS:
+ return bma400_get_steps_reg(data, val);
+ default:
+ return -EINVAL;
+ }
case IIO_CHAN_INFO_RAW:
mutex_lock(&data->mutex);
ret = bma400_get_accel_reg(data, chan, val);
@@ -753,6 +802,9 @@ static int bma400_read_raw(struct iio_dev *indio_dev,

*val = data->oversampling_ratio;
return IIO_VAL_INT;
+ case IIO_CHAN_INFO_ENABLE:
+ *val = data->steps_enabled;
+ return IIO_VAL_INT;
default:
return -EINVAL;
}
@@ -818,6 +870,11 @@ static int bma400_write_raw(struct iio_dev *indio_dev,
ret = bma400_set_accel_oversampling_ratio(data, val);
mutex_unlock(&data->mutex);
return ret;
+ case IIO_CHAN_INFO_ENABLE:
+ mutex_lock(&data->mutex);
+ ret = bma400_enable_steps(data, val);
+ mutex_unlock(&data->mutex);
+ return ret;
default:
return -EINVAL;
}
@@ -834,6 +891,8 @@ static int bma400_write_raw_get_fmt(struct iio_dev *indio_dev,
return IIO_VAL_INT_PLUS_MICRO;
case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
return IIO_VAL_INT;
+ case IIO_CHAN_INFO_ENABLE:
+ return IIO_VAL_INT;
default:
return -EINVAL;
}
--
2.17.1


2022-04-27 13:01:09

by Andy Shevchenko

[permalink] [raw]
Subject: Re: [PATCH v4 5/9] iio: accel: bma400: Add separate channel for step counter

On Wed, Apr 20, 2022 at 11:11 PM Jagath Jog J <[email protected]> wrote:
>
> Added channel for step counter which can be enable or disable
> through the sysfs interface.

...

> +static int bma400_enable_steps(struct bma400_data *data, int val)
> +{
> + int ret;
> +
> + if (data->steps_enabled == val)
> + return 0;
> +
> + ret = regmap_update_bits(data->regmap, BMA400_INT_CONFIG1_REG,
> + BMA400_STEP_INT_MSK,
> + FIELD_PREP(BMA400_STEP_INT_MSK, !!val));

> + data->steps_enabled = val;

This will update the value even if we got an error and actual device
state is unknown here. Does this make sense?

> + return ret;
> +}

...

I perhaps missed why kmalloc() is needed now. Any pointers to the discussion?

--
With Best Regards,
Andy Shevchenko

2022-04-29 01:04:56

by Jagath Jog J

[permalink] [raw]
Subject: Re: [PATCH v4 5/9] iio: accel: bma400: Add separate channel for step counter

Hi Andy,

On Wed, Apr 27, 2022 at 6:04 PM Andy Shevchenko
<[email protected]> wrote:
>
> On Wed, Apr 20, 2022 at 11:11 PM Jagath Jog J <[email protected]> wrote:
> >
> > Added channel for step counter which can be enable or disable
> > through the sysfs interface.
>
> ...
>
> > +static int bma400_enable_steps(struct bma400_data *data, int val)
> > +{
> > + int ret;
> > +
> > + if (data->steps_enabled == val)
> > + return 0;
> > +
> > + ret = regmap_update_bits(data->regmap, BMA400_INT_CONFIG1_REG,
> > + BMA400_STEP_INT_MSK,
> > + FIELD_PREP(BMA400_STEP_INT_MSK, !!val));
>
> > + data->steps_enabled = val;
>
> This will update the value even if we got an error and actual device
> state is unknown here. Does this make sense?

I will correct this in the next series.

>
> > + return ret;
> > +}
>
> ...
>
> I perhaps missed why kmalloc() is needed now. Any pointers to the discussion?

Here step is a 24-bit value and since this is a sysfs channel read (slow path),
kmalloc() is used to make the buffer DMA safe to read the multibyte value
using regmap_bulk_read().

>
> --
> With Best Regards,
> Andy Shevchenko

Thank you,
Jagath