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Message-ID: <20150805092418.GA20023@hard-bop>
Date: Wed, 5 Aug 2015 12:24:18 +0300
From: Teodora Baluta <teodora.baluta@...el.com>
To: Peter Meerwald <pmeerw@...erw.net>
Cc: jic23@...nel.org, knaack.h@....de, lars@...afoo.de,
daniel.baluta@...el.com, linux-iio@...r.kernel.org,
linux-kernel@...r.kernel.org
Subject: Re: [PATCH 2/3] iio: mxc4005: add triggered buffer mode for mxc4005
On Fri, Jul 31, 2015 at 06:43:57PM +0200, Peter Meerwald wrote:
> On Fri, 31 Jul 2015, Teodora Baluta wrote:
>
> > This patch adds support for buffered readings for the 3-axis
> > accelerometer mxc4005.
>
> some comments below
Thanks for the review, Peter. I will send a version 2 patch set as soon
as possible to address the comments.
Teodora
>
> > Signed-off-by: Teodora Baluta <teodora.baluta@...el.com>
> > ---
> > drivers/iio/accel/Kconfig | 2 ++
> > drivers/iio/accel/mxc4005.c | 75 ++++++++++++++++++++++++++++++++++++++++++---
> > 2 files changed, 73 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig
> > index 7f534a3..e8d135e 100644
> > --- a/drivers/iio/accel/Kconfig
> > +++ b/drivers/iio/accel/Kconfig
> > @@ -140,6 +140,8 @@ config MMA9553
> > config MXC4005
> > tristate "Memsic MXC4005XC 3-Axis Accelerometer Driver"
> > depends on I2C
> > + select IIO_BUFFER
> > + select IIO_TRIGGERED_BUFFER
> > select REGMAP_I2C
> > help
> > Say yes here to build support for the Memsic MXC4005XC 3-axis
> > diff --git a/drivers/iio/accel/mxc4005.c b/drivers/iio/accel/mxc4005.c
> > index 0f0410c..114c14d 100644
> > --- a/drivers/iio/accel/mxc4005.c
> > +++ b/drivers/iio/accel/mxc4005.c
> > @@ -19,6 +19,9 @@
> > #include <linux/acpi.h>
> > #include <linux/regmap.h>
> > #include <linux/iio/sysfs.h>
> > +#include <linux/iio/buffer.h>
> > +#include <linux/iio/triggered_buffer.h>
> > +#include <linux/iio/trigger_consumer.h>
> >
> > #define MXC4005_DRV_NAME "mxc4005"
> > #define MXC4005_REGMAP_NAME "mxc4005_regmap"
> > @@ -54,6 +57,7 @@ struct mxc4005_data {
> > struct i2c_client *client;
> > struct mutex mutex;
> > struct regmap *regmap;
> > + s16 buffer[8];
>
> be16 buffer[3]; ?!
>
> > };
> >
> > /*
> > @@ -125,6 +129,20 @@ static const struct regmap_config mxc4005_regmap_config = {
> > .writeable_reg = mxc4005_is_writeable_reg,
> > };
> >
> > +static int mxc4005_read_xyz(struct mxc4005_data *data)
> > +{
> > + int ret;
> > +
> > + ret = regmap_bulk_read(data->regmap, MXC4005_REG_XOUT_UPPER,
> > + (u8 *) data->buffer, sizeof(data->buffer));
>
> sizeof(data->buffer) == sizeof(s16) * 8 == 16 bytes, but actually the
> sensor data is just 6 bytes!?
>
> > + if (ret < 0) {
> > + dev_err(&data->client->dev, "failed to read axes\n");
> > + return ret;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > static int mxc4005_read_axis(struct mxc4005_data *data,
> > int axis)
> > {
> > @@ -190,6 +208,7 @@ static int mxc4005_read_raw(struct iio_dev *indio_dev,
> > int *val, int *val2, long mask)
> > {
> > struct mxc4005_data *data = iio_priv(indio_dev);
> > + int axis = chan->scan_index;
>
> why?
> BTW w.r.t the initial patch: chan->address could store the register
> address directly, so MXC4005_AXIS_TO_REG() could be dropped
>
> > int ret;
> >
> > switch (mask) {
> > @@ -200,12 +219,13 @@ static int mxc4005_read_raw(struct iio_dev *indio_dev,
> > return -EBUSY;
> >
> > mutex_lock(&data->mutex);
> > - ret = mxc4005_read_axis(data, chan->address);
> > + ret = mxc4005_read_axis(data, axis);
> > mutex_unlock(&data->mutex);
> > if (ret < 0)
> > return ret;
> > ret = be16_to_cpu(ret);
> > - *val = sign_extend32(ret >> 4, 11);
> > + *val = sign_extend32(ret >> chan->scan_type.shift,
> > + chan->scan_type.realbits - 1);
> > return IIO_VAL_INT;
> > default:
> > return -EINVAL;
> > @@ -259,17 +279,47 @@ static const struct iio_info mxc4005_info = {
> > .type = IIO_ACCEL, \
> > .modified = 1, \
> > .channel2 = IIO_MOD_##_axis, \
> > - .address = AXIS_##_axis, \
> > .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
> > .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
> > + .scan_index = AXIS_##_axis, \
> > + .scan_type = { \
> > + .sign = 's', \
> > + .realbits = 12, \
> > + .storagebits = 16, \
> > + .shift = 4, \
> > + .endianness = IIO_BE, \
> > + }, \
> > }
> >
> > static const struct iio_chan_spec mxc4005_channels[] = {
> > MXC4005_CHANNEL(X),
> > MXC4005_CHANNEL(Y),
> > MXC4005_CHANNEL(Z),
> > + IIO_CHAN_SOFT_TIMESTAMP(3),
> > };
> >
> > +static irqreturn_t mxc4005_trigger_handler(int irq, void *private)
> > +{
> > + struct iio_poll_func *pf = private;
> > + struct iio_dev *indio_dev = pf->indio_dev;
> > + struct mxc4005_data *data = iio_priv(indio_dev);
> > + int ret;
> > +
> > + mutex_lock(&data->mutex);
> > + ret = mxc4005_read_xyz(data);
>
> this always reads all channels, what if only one channel is enabled by the
> user? use available_scan_masks...
>
> > + mutex_unlock(&data->mutex);
> > + if (ret < 0)
> > + goto err;
> > +
> > + iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
> > + iio_get_time_ns());
> > +
> > +err:
> > + iio_trigger_notify_done(indio_dev->trig);
> > +
> > + return IRQ_HANDLED;
> > +}
> > +
> > static int mxc4005_chip_init(struct mxc4005_data *data)
> > {
> > int ret;
> > @@ -324,14 +374,29 @@ static int mxc4005_probe(struct i2c_client *client,
> > indio_dev->modes = INDIO_DIRECT_MODE;
> > indio_dev->info = &mxc4005_info;
> >
> > + ret = iio_triggered_buffer_setup(indio_dev,
> > + &iio_pollfunc_store_time,
> > + mxc4005_trigger_handler,
> > + NULL);
> > + if (ret < 0) {
> > + dev_err(&client->dev,
> > + "failed to setup iio triggered buffer\n");
> > + return ret;
> > + }
> > +
> > ret = iio_device_register(indio_dev);
> > if (ret < 0) {
> > dev_err(&client->dev,
> > "unable to register iio device %d\n", ret);
> > - return ret;
> > + goto err_buffer_cleanup;
> > }
> >
> > return 0;
> > +
> > +err_buffer_cleanup:
> > + iio_triggered_buffer_cleanup(indio_dev);
> > +
> > + return ret;
> > }
> >
> > static int mxc4005_remove(struct i2c_client *client)
> > @@ -340,6 +405,8 @@ static int mxc4005_remove(struct i2c_client *client)
> >
> > iio_device_unregister(indio_dev);
> >
> > + iio_triggered_buffer_cleanup(indio_dev);
> > +
> > return 0;
> > }
> >
> >
>
> --
>
> Peter Meerwald
> +43-664-2444418 (mobile)
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