diff mbox series

[v4,5/9] iio: accel: bma400: Add separate channel for step counter

Message ID 20220420211105.14654-6-jagathjog1996@gmail.com (mailing list archive)
State Changes Requested
Headers show
Series iio: accel: bma400: Add buffer, step and activity/inactivity | expand

Commit Message

Jagath Jog J April 20, 2022, 9:11 p.m. UTC 
Added channel for step counter which can be enable or disable
through the sysfs interface.

Signed-off-by: Jagath Jog J <jagathjog1996@gmail.com>
---
 drivers/iio/accel/bma400.h      |  2 +
 drivers/iio/accel/bma400_core.c | 67 +++++++++++++++++++++++++++++++--
 2 files changed, 65 insertions(+), 4 deletions(-)

Comments

Andy Shevchenko April 27, 2022, 12:34 p.m. UTC | #1 
On Wed, Apr 20, 2022 at 11:11 PM Jagath Jog J <jagathjog1996@gmail.com> 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?
Jagath Jog J April 27, 2022, 9:01 p.m. UTC | #2 
Hi Andy,

On Wed, Apr 27, 2022 at 6:04 PM Andy Shevchenko
<andy.shevchenko@gmail.com> wrote:
>
> On Wed, Apr 20, 2022 at 11:11 PM Jagath Jog J <jagathjog1996@gmail.com> 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
diff mbox series

Patch

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;
 	}