Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753836AbbHaQgr (ORCPT ); Mon, 31 Aug 2015 12:36:47 -0400 Received: from saturn.retrosnub.co.uk ([178.18.118.26]:38354 "EHLO saturn.retrosnub.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753679AbbHaQgq (ORCPT ); Mon, 31 Aug 2015 12:36:46 -0400 Subject: Re: [PATCH v3 2/3] iio: mxc4005: add triggered buffer mode for mxc4005 To: Teodora Baluta References: <1440081453-12600-1-git-send-email-teodora.baluta@intel.com> <1440081453-12600-3-git-send-email-teodora.baluta@intel.com> Cc: knaack.h@gmx.de, lars@metafoo.de, pmeerw@pmeerw.net, daniel.baluta@intel.com, linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org From: Jonathan Cameron Message-ID: <55E4829C.40303@kernel.org> Date: Mon, 31 Aug 2015 17:36:44 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.2.0 MIME-Version: 1.0 In-Reply-To: <1440081453-12600-3-git-send-email-teodora.baluta@intel.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6021 Lines: 201 On 20/08/15 15:37, Teodora Baluta wrote: > This patch adds support for buffered readings for the 3-axis > accelerometer mxc4005. > > Signed-off-by: Teodora Baluta Hi Teodora, You rather missed the point on using the iio_pollfunc_store_time function. See below. Anyhow, as that was on the only issue, I've fixed it up. Please check the results. Applied to the togreg branch of iio.git - initially pushed out as testing for the autobuilders to play with it. Thanks, Jonathan > --- > drivers/iio/accel/Kconfig | 2 ++ > drivers/iio/accel/mxc4005.c | 79 +++++++++++++++++++++++++++++++++++++++++++-- > 2 files changed, 78 insertions(+), 3 deletions(-) > > diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig > index 69302be..cd5cd24 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 e15c1bd..95b91b5 100644 > --- a/drivers/iio/accel/mxc4005.c > +++ b/drivers/iio/accel/mxc4005.c > @@ -19,6 +19,9 @@ > #include > #include > #include > +#include > +#include > +#include > > #define MXC4005_DRV_NAME "mxc4005" > #define MXC4005_REGMAP_NAME "mxc4005_regmap" > @@ -52,6 +55,7 @@ struct mxc4005_data { > struct device *dev; > struct mutex mutex; > struct regmap *regmap; > + __be16 buffer[8]; > }; > > /* > @@ -122,6 +126,20 @@ 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)); > + if (ret < 0) { > + dev_err(data->dev, "failed to read axes\n"); > + return ret; > + } > + > + return 0; > +} > + > static int mxc4005_read_axis(struct mxc4005_data *data, > unsigned int addr) > { > @@ -197,7 +215,8 @@ static int mxc4005_read_raw(struct iio_dev *indio_dev, > ret = mxc4005_read_axis(data, chan->address); > if (ret < 0) > return 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; > @@ -239,6 +258,11 @@ static const struct iio_info mxc4005_info = { > .attrs = &mxc4005_attrs_group, > }; > > +static const unsigned long mxc4005_scan_masks[] = { > + BIT(AXIS_X) | BIT(AXIS_Y) | BIT(AXIS_Z), > + 0 > +}; > + > #define MXC4005_CHANNEL(_axis, _addr) { \ > .type = IIO_ACCEL, \ > .modified = 1, \ > @@ -246,14 +270,43 @@ static const struct iio_info mxc4005_info = { > .address = _addr, \ > .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_REG_XOUT_UPPER), > MXC4005_CHANNEL(Y, MXC4005_REG_YOUT_UPPER), > MXC4005_CHANNEL(Z, MXC4005_REG_ZOUT_UPPER), > + 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; > + > + ret = mxc4005_read_xyz(data); > + if (ret < 0) > + goto err; > + > + iio_push_to_buffers_with_timestamp(indio_dev, data->buffer, > + iio_get_time_ns()); The whole purpose of the storetime pollfunc is to ensure we get a timestamp as close as possible to the time of the interrupt. Reading the time again instead of using the stashed version is not a good plan! > + > +err: > + iio_trigger_notify_done(indio_dev->trig); > + > + return IRQ_HANDLED; > +} > + > static int mxc4005_chip_init(struct mxc4005_data *data) > { > int ret; > @@ -304,23 +357,43 @@ static int mxc4005_probe(struct i2c_client *client, > indio_dev->dev.parent = &client->dev; > indio_dev->channels = mxc4005_channels; > indio_dev->num_channels = ARRAY_SIZE(mxc4005_channels); > + indio_dev->available_scan_masks = mxc4005_scan_masks; > indio_dev->name = MXC4005_DRV_NAME; > 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) > { > - iio_device_unregister(i2c_get_clientdata(client)); > + struct iio_dev *indio_dev = i2c_get_clientdata(client); > + > + iio_device_unregister(indio_dev); > + > + iio_triggered_buffer_cleanup(indio_dev); > > return 0; > } > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/