Re: [PATCH v4 8/8] iio: adc: ad7606: add support for AD7606C-{16,18} parts

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Fri, Sep 6, 2024 at 8:34 AM Alexandru Ardelean
<aardelean@xxxxxxxxxxxx> wrote:
>
> On Fri, Sep 6, 2024 at 2:30 AM David Lechner <dlechner@xxxxxxxxxxxx> wrote:
> >
> > On 9/5/24 3:24 AM, Alexandru Ardelean wrote:
> > > The AD7606C-16 and AD7606C-18 are pretty similar with the AD7606B.
> > > The main difference between AD7606C-16 & AD7606C-18 is the precision in
> > > bits (16 vs 18).
> > > Because of that, some scales need to be defined for the 18-bit variants, as
> > > they need to be computed against 2**18 (vs 2**16 for the 16 bit-variants).
> > >
> > > Because the AD7606C-16,18 also supports bipolar & differential channels,
> > > for SW-mode, the default range of 10 V or ±10V should be set at probe.
> > > On reset, the default range (in the registers) is set to value 0x3 which
> > > corresponds to '±10 V single-ended range', regardless of bipolar or
> > > differential configuration.
> > >
> > > Aside from the scale/ranges, the AD7606C-16 is similar to the AD7606B.
> > >
> > > The AD7606C-18 variant offers 18-bit precision. Because of this, the
> > > requirement to use this chip is that the SPI controller supports padding
> > > of 18-bit sequences to 32-bit arrays.
> > >
> > > Datasheet links:
> > >   https://www.analog.com/media/en/technical-documentation/data-sheets/ad7606c-16.pdf
> > >   https://www.analog.com/media/en/technical-documentation/data-sheets/ad7606c-18.pdf
> > >
> > > Signed-off-by: Alexandru Ardelean <aardelean@xxxxxxxxxxxx>
> > > ---
> > >  drivers/iio/adc/ad7606.c     | 266 +++++++++++++++++++++++++++++++----
> > >  drivers/iio/adc/ad7606.h     |  17 ++-
> > >  drivers/iio/adc/ad7606_spi.c |  55 ++++++++
> > >  3 files changed, 309 insertions(+), 29 deletions(-)
> > >
> > > diff --git a/drivers/iio/adc/ad7606.c b/drivers/iio/adc/ad7606.c
> > > index 4c3fbb28f790..999c4411859e 100644
> > > --- a/drivers/iio/adc/ad7606.c
> > > +++ b/drivers/iio/adc/ad7606.c
> > > @@ -28,14 +28,44 @@
> > >
> > >  #include "ad7606.h"
> > >
> > > +typedef void (*ad7606c_chan_setup_cb_t)(struct ad7606_state *st, int ch,
> > > +                                     bool bipolar, bool differential);
> > > +
> > >  /*
> > >   * Scales are computed as 5000/32768 and 10000/32768 respectively,
> > >   * so that when applied to the raw values they provide mV values
> > >   */
> > > -static const unsigned int ad7606_scale_avail[2] = {
> > > +static const unsigned int ad7606_16bit_hw_scale_avail[2] = {
> > >       152588, 305176
> > >  };
> > >
> > > +static const unsigned int ad7606_18bit_hw_scale_avail[2] = {
> > > +     38147, 76294
> > > +};
> > > +
> > > +static const unsigned int ad7606c_16_scale_single_ended_unipolar_avail[3] = {
> > > +     76294, 152588, 190735,
> > > +};
> > > +
> > > +static const unsigned int ad7606c_16_scale_single_ended_bipolar_avail[5] = {
> > > +     76294, 152588, 190735, 305176, 381470
> > > +};
> > > +
> > > +static const unsigned int ad7606c_16_scale_differential_bipolar_avail[4] = {
> > > +     152588, 305176, 381470, 610352
> > > +};
> > > +
> > > +static const unsigned int ad7606c_18_scale_single_ended_unipolar_avail[3] = {
> > > +     19073, 38147, 47684
> > > +};
> > > +
> > > +static const unsigned int ad7606c_18_scale_single_ended_bipolar_avail[5] = {
> > > +     19073, 38147, 47684, 76294, 95367
> > > +};
> > > +
> > > +static const unsigned int ad7606c_18_scale_differential_bipolar_avail[4] = {
> > > +     38147, 76294, 95367, 152588
> > > +};
> > >
> > >  static const unsigned int ad7616_sw_scale_avail[3] = {
> > >       76293, 152588, 305176
> > > @@ -82,11 +112,19 @@ static int ad7606_reg_access(struct iio_dev *indio_dev,
> > >       }
> > >  }
> > >
> > > -static int ad7606_read_samples(struct ad7606_state *st)
> > > +static int ad7606_read_samples(struct ad7606_state *st, bool sign_extend_samples)
> > >  {
> > > +     unsigned int storagebits = st->chip_info->channels[1].scan_type.storagebits;
> >
> > Why [1]? Sure, they are all the same, but [0] would seem less arbitrary.
>
> [0] is the timestamp channel.
>
>
> >
> > >       unsigned int num = st->chip_info->num_channels - 1;
> > > -     u16 *data = st->data;
> > > -     int ret;
> > > +     u32 *data32 = st->data.d32;
> > > +     u16 *data16 = st->data.d16;
> > > +     void *data;
> > > +     int i, ret;
> > > +
> > > +     if (storagebits > 16)
> > > +             data = data32;
> > > +     else
> > > +             data = data16;
> > >
> > >       /*
> > >        * The frstdata signal is set to high while and after reading the sample
> > > @@ -108,11 +146,25 @@ static int ad7606_read_samples(struct ad7606_state *st)
> > >                       return -EIO;
> > >               }
> > >
> > > -             data++;
> > > +             if (storagebits > 16)
> > > +                     data32++;
> > > +             else
> > > +                     data16++;
> > >               num--;
> > >       }
> > >
> > > -     return st->bops->read_block(st->dev, num, data);
> > > +     ret = st->bops->read_block(st->dev, num, data);
> >
> > Since data++ was removed, this looks broken now as well as the
> > other read_block() not visible in the diff.
> >
> > Maybe better to drop data32 and data16, keep the change of data
> > to void*, and change data++ to data += BITS_TO_BYTES(storagebits)?
> >
> > Although, all of this might be moot since it looks like this
> > needs to be rebased on [1].
> >
> > [1]: https://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio.git/commit/?h=fixes-togreg&id=90826e08468ba7fb35d8b39645b22d9e80004afe
>
> Oh.
> Omitted that patch.
> I forgot that fixes-togreg has a different cadence in another branch.
>
> >
> > > +     if (ret)
> > > +             return ret;
> > > +
> > > +     if (storagebits == 16 || !sign_extend_samples)
> > > +             return 0;
> > > +
> > > +     /* For 18 bit samples, we need to sign-extend samples to 32 bits */
> > > +     for (i = 0; i < num; i++)
> > > +             data32[i] = sign_extend32(data32[i], 17);> +
> > > +     return 0;
> > >  }
> > >
> > >  static irqreturn_t ad7606_trigger_handler(int irq, void *p)
> > > @@ -124,11 +176,11 @@ static irqreturn_t ad7606_trigger_handler(int irq, void *p)
> > >
> > >       guard(mutex)(&st->lock);
> > >
> > > -     ret = ad7606_read_samples(st);
> > > +     ret = ad7606_read_samples(st, true);
> >
> > Shouldn't the sign_extend parameter depend on if the data is unipolar or bipolar?
>
> [c1]
> Sign-extension is only needed for 18-bit samples.
> 16-bit samples are already properly sign(ed), but to 16-bits.
>
> It's a slight performance improvement, that may look quirky here.
> The idea here, is that for ad7606_scan_direct() we only need to
> sign-extend 1 sample of the 8 samples we get.
> And we need to sign-extend it to 32 bits regardless of it being 16-bit
> or 18-bit.
>
> In ad7606_trigger_handler(), the 16-bit samples were pushed as-is.
> Which means that we need to sign-extend the samples at least for
> 18-bits (as it is a new part)
> The question now becomes if we should sign-extend to 32-bits, 16-bit
> samples in ad7606_trigger_handler(), as that may break some ABI.
>
> >
> > >       if (ret)
> > >               goto error_ret;
> > >
> > > -     iio_push_to_buffers_with_timestamp(indio_dev, st->data,
> > > +     iio_push_to_buffers_with_timestamp(indio_dev, st->data.d16,
> > >                                          iio_get_time_ns(indio_dev));
> > >  error_ret:
> > >       iio_trigger_notify_done(indio_dev->trig);
> > > @@ -142,6 +194,7 @@ static int ad7606_scan_direct(struct iio_dev *indio_dev, unsigned int ch,
> > >                             int *val)
> > >  {
> > >       struct ad7606_state *st = iio_priv(indio_dev);
> > > +     unsigned int storagebits = st->chip_info->channels[1].scan_type.storagebits;
> > >       int ret;
> > >
> > >       gpiod_set_value(st->gpio_convst, 1);
> > > @@ -152,9 +205,13 @@ static int ad7606_scan_direct(struct iio_dev *indio_dev, unsigned int ch,
> > >               goto error_ret;
> > >       }
> > >
> > > -     ret = ad7606_read_samples(st);
> > > -     if (ret == 0)
> > > -             *val = sign_extend32(st->data[ch], 15);
> > > +     ret = ad7606_read_samples(st, false);
> >
> > Why not let ad7606_read_samples() do the sign extending since
> > it can do that now?
>
> Related to comment [c1]
>
> >
> > > +     if (ret == 0) {
> > > +             if (storagebits > 16)
> > > +                     *val = sign_extend32(st->data.d32[ch], 17);
> > > +             else
> > > +                     *val = sign_extend32(st->data.d16[ch], 15);
> > > +     }
> > >
> > >  error_ret:
> > >       gpiod_set_value(st->gpio_convst, 0);
> > > @@ -267,7 +324,7 @@ static int ad7606_write_raw(struct iio_dev *indio_dev,
> > >                       ch = chan->address;
> > >               cs = &st->chan_scales[ch];
> > >               i = find_closest(val2, cs->scale_avail, cs->num_scales);
> > > -             ret = st->write_scale(indio_dev, ch, i);
> > > +             ret = st->write_scale(indio_dev, ch, i + cs->reg_offset);
> > >               if (ret < 0)
> > >                       return ret;
> > >               cs->range = i;
> > > @@ -350,6 +407,18 @@ static const struct iio_chan_spec ad7606_channels_16bit[] = {
> > >       AD7606_CHANNEL(7, 16),
> > >  };
> > >
> > > +static const struct iio_chan_spec ad7606_channels_18bit[] = {
> > > +     IIO_CHAN_SOFT_TIMESTAMP(8),
> > > +     AD7606_CHANNEL(0, 18),
> > > +     AD7606_CHANNEL(1, 18),
> > > +     AD7606_CHANNEL(2, 18),
> > > +     AD7606_CHANNEL(3, 18),
> > > +     AD7606_CHANNEL(4, 18),
> > > +     AD7606_CHANNEL(5, 18),
> > > +     AD7606_CHANNEL(6, 18),
> > > +     AD7606_CHANNEL(7, 18),
> > > +};
> > > +
> > >  /*
> > >   * The current assumption that this driver makes for AD7616, is that it's
> > >   * working in Hardware Mode with Serial, Burst and Sequencer modes activated.
> > > @@ -410,6 +479,18 @@ static const struct ad7606_chip_info ad7606_chip_info_tbl[] = {
> > >               .oversampling_avail = ad7606_oversampling_avail,
> > >               .oversampling_num = ARRAY_SIZE(ad7606_oversampling_avail),
> > >       },
> > > +     [ID_AD7606C_16] = {
> > > +             .channels = ad7606_channels_16bit,
> > > +             .num_channels = 9,
> >
> > Could be nice to have a cleanup patch before this to convert others to
> > use ARRAY_SIZE(), then use ARRAY_SIZE(ad7606_channels_16bit) here
> > instead of 9.
>
> Ack.

I'll need to revert this to a NACK.

"ad7606_channels{_16bit}" has 9 elements.
But for some ADC variants, only 7 are used.
So, num_channels is specified as 7 there, and references this same array.
Which also explains why the timestamp channel is the first.

>
> >
> > > +             .oversampling_avail = ad7606_oversampling_avail,
> > > +             .oversampling_num = ARRAY_SIZE(ad7606_oversampling_avail),
> > > +     },
> > > +     [ID_AD7606C_18] = {
> > > +             .channels = ad7606_channels_18bit,
> > > +             .num_channels = 9,

Continuing here: I could make it ARRAY_SIZE(ad7606_channels_18bit),
but that would make it less consistent with the other "num_channels"
styles.
And maybe there will be a 4 or 6 channel 18 bit part later.

> > > +             .oversampling_avail = ad7606_oversampling_avail,
> > > +             .oversampling_num = ARRAY_SIZE(ad7606_oversampling_avail),
> > > +     },
> > >       [ID_AD7616] = {
> > >               .channels = ad7616_channels,
> > >               .num_channels = 17,
> > > @@ -581,7 +662,122 @@ static const struct iio_trigger_ops ad7606_trigger_ops = {
> > >       .validate_device = iio_trigger_validate_own_device,
> > >  };
> > >
> > > -static int ad7606_sw_mode_setup(struct iio_dev *indio_dev)
> > > +static void ad7606c_18_chan_setup(struct ad7606_state *st, int ch,
> > > +                               bool bipolar, bool differential)
> > > +{
> > > +     struct ad7606_chan_scale *cs = &st->chan_scales[ch];
> > > +
> > > +     if (differential) {
> > > +             cs->scale_avail =
> > > +                     ad7606c_18_scale_differential_bipolar_avail;
> > > +             cs->num_scales =
> > > +                     ARRAY_SIZE(ad7606c_18_scale_differential_bipolar_avail);
> > > +             /* Bipolar differential ranges start at 8 (b1000) */
> > > +             cs->reg_offset = 8;
> > > +             cs->range = 1;
> > > +     } else if (bipolar) {
> > > +             cs->scale_avail =
> > > +                     ad7606c_18_scale_single_ended_bipolar_avail;
> > > +             cs->num_scales =
> > > +                     ARRAY_SIZE(ad7606c_18_scale_single_ended_bipolar_avail);
> >
> > I guess cs->reg_offset is 0 for this one?
>
> Yes.
> I will make it explicit.
>
> >
> > > +             cs->range = 3;
> > > +     } else {
> > > +             cs->scale_avail =
> > > +                     ad7606c_18_scale_single_ended_unipolar_avail;
> > > +             cs->num_scales =
> > > +                     ARRAY_SIZE(ad7606c_18_scale_single_ended_unipolar_avail);
> > > +             /* Unipolar single-ended ranges start at 5 (b0101) */
> > > +             cs->reg_offset = 5;
> > > +             cs->range = 1;
> > > +     }
> > > +}
> > > +
> > > +static void ad7606c_16_chan_setup(struct ad7606_state *st, int ch,
> > > +                               bool bipolar, bool differential)
> > > +{
> > > +     struct ad7606_chan_scale *cs = &st->chan_scales[ch];
> > > +
> > > +     if (differential) {
> > > +             cs->scale_avail =
> > > +                     ad7606c_16_scale_differential_bipolar_avail;
> > > +             cs->num_scales =
> > > +                     ARRAY_SIZE(ad7606c_16_scale_differential_bipolar_avail);
> > > +             /* Bipolar differential ranges start at 8 (b1000) */
> > > +             cs->reg_offset = 8;
> > > +             cs->range = 1;
> > > +     } else if (bipolar) {
> > > +             cs->scale_avail =
> > > +                     ad7606c_16_scale_single_ended_bipolar_avail;
> > > +             cs->num_scales =
> > > +                     ARRAY_SIZE(ad7606c_16_scale_single_ended_bipolar_avail);
> > > +             cs->range = 3;
> > > +     } else {
> > > +             cs->scale_avail =
> > > +                     ad7606c_16_scale_single_ended_unipolar_avail;
> > > +             cs->num_scales =
> > > +                     ARRAY_SIZE(ad7606c_16_scale_single_ended_unipolar_avail);
> > > +             /* Unipolar single-ended ranges start at 5 (b0101) */
> > > +             cs->reg_offset = 5;
> > > +             cs->range = 1;
> > > +     }
> > > +}
> > > +
> > > +static int ad7606c_sw_mode_setup_channels(struct iio_dev *indio_dev,
> > > +                                       ad7606c_chan_setup_cb_t chan_setup_cb)
> > > +{
> > > +     unsigned int num_channels = indio_dev->num_channels - 1;
> > > +     struct ad7606_state *st = iio_priv(indio_dev);
> > > +     bool chan_configured[AD760X_MAX_CHANNELS] = {};
> > > +     struct device *dev = st->dev;
> > > +     int ret;
> > > +     u32 ch;
> > > +
> > > +     /* We need to hook this first */
> >
> > Comment would be more useful if it said why.
>
> Ack.
> Will add.
>
> >
> > > +     ret = st->bops->sw_mode_config(indio_dev);
> > > +     if (ret)
> > > +             return ret;
> > > +
> > > +     device_for_each_child_node_scoped(dev, child) {
> > > +             bool bipolar, differential;
> > > +             u32 pins[2];
> > > +
> > > +             ret = fwnode_property_read_u32(child, "reg", &ch);
> > > +             if (ret)
> > > +                     continue;
> > > +
> > > +             /* channel number (here) is from 1 to num_channels */
> > > +             if (ch == 0 || ch > num_channels) {
> > > +                     dev_warn(st->dev,
> > > +                              "Invalid channel number (ignoring): %d\n", ch);
> > > +                     continue;
> > > +             }
> > > +
> > > +             bipolar = fwnode_property_present(child, "bipolar");
> >
> > IIRC, fwnode_property_read_bool() is preferred for bool/flag properties.
>
> Ack.
>
> >
> > > +
> > > +             ret = fwnode_property_read_u32_array(child, "diff-channels",
> > > +                                                  pins, ARRAY_SIZE(pins));
> > > +             /* Channel is differential, if pins are the same as 'reg' */
> > > +             if (ret == 0 && pins[0] == ch && pins[1] == ch)
> > > +                     differential = true;
> > > +             else
> > > +                     differential = false;
> >
> > Would probably better to error on bad pin numbers rather than default to
> > not differential.
>
> No strong preference from my side.
> Will implement failure/error case.
>
> >
> > > +
> > > +             ch--;
> > > +
> > > +             chan_setup_cb(st, ch, bipolar, differential);
> > > +             chan_configured[ch] = true;
> > > +     }
> > > +
> > > +     /* Apply default configuration to unconfigured (via DT) channels */
> > > +     for (ch = 0; ch < num_channels; ch++) {
> > > +             if (!chan_configured[ch])
> > > +                     chan_setup_cb(st, ch, false, false);
> > > +     }
> > > +
> > > +     return 0;
> > > +}
> > > +
> > > +static int ad7606_sw_mode_setup(struct iio_dev *indio_dev, unsigned int id)
> > >  {
> > >       unsigned int num_channels = indio_dev->num_channels - 1;
> > >       struct ad7606_state *st = iio_priv(indio_dev);
> > > @@ -596,17 +792,30 @@ static int ad7606_sw_mode_setup(struct iio_dev *indio_dev)
> > >
> > >       indio_dev->info = &ad7606_info_sw_mode;
> > >
> > > -     /* Scale of 0.076293 is only available in sw mode */
> > > -     /* After reset, in software mode, ±10 V is set by default */
> > > -     for (ch = 0; ch < num_channels; ch++) {
> > > -             struct ad7606_chan_scale *cs = &st->chan_scales[ch];
> > > +     switch (id) {
> > > +     case ID_AD7606C_18:
> > > +             ret = ad7606c_sw_mode_setup_channels(indio_dev,
> > > +                                                  ad7606c_18_chan_setup);
> > > +             break;
> > > +     case ID_AD7606C_16:
> > > +             ret = ad7606c_sw_mode_setup_channels(indio_dev,
> > > +                                                  ad7606c_16_chan_setup);
> > > +             break;
> > > +     default:
> > > +             /* Scale of 0.076293 is only available in sw mode */
> > > +             /* After reset, in software mode, ±10 V is set by default */
> > > +             for (ch = 0; ch < num_channels; ch++) {
> > > +                     struct ad7606_chan_scale *cs = &st->chan_scales[ch];
> > > +
> > > +                     cs->scale_avail = ad7616_sw_scale_avail;
> > > +                     cs->num_scales = ARRAY_SIZE(ad7616_sw_scale_avail);
> > > +                     cs->range = 2;
> > > +             }
> > >
> > > -             cs->scale_avail = ad7616_sw_scale_avail;
> > > -             cs->num_scales = ARRAY_SIZE(ad7616_sw_scale_avail);
> > > -             cs->range = 2;
> > > +             ret = st->bops->sw_mode_config(indio_dev);
> > > +             break;
> > >       }
> > >
> > > -     ret = st->bops->sw_mode_config(indio_dev);
> > >       if (ret)
> > >               return ret;
> > >
> > > @@ -655,9 +864,16 @@ int ad7606_probe(struct device *dev, int irq, void __iomem *base_address,
> > >       st->oversampling = 1;
> > >
> > >       cs = &st->chan_scales[0];
> > > -     cs->range = 0;
> > > -     cs->scale_avail = ad7606_scale_avail;
> > > -     cs->num_scales = ARRAY_SIZE(ad7606_scale_avail);
> > > +     switch (id) {
> > > +     case ID_AD7606C_18:
> > > +             cs->scale_avail = ad7606_18bit_hw_scale_avail;
> > > +             cs->num_scales = ARRAY_SIZE(ad7606_18bit_hw_scale_avail);
> > > +             break;
> > > +     default:
> > > +             cs->scale_avail = ad7606_16bit_hw_scale_avail;
> > > +             cs->num_scales = ARRAY_SIZE(ad7606_16bit_hw_scale_avail);
> > > +             break;
> > > +     }
> > >
> > >       ret = devm_regulator_get_enable(dev, "avcc");
> > >       if (ret)
> > > @@ -706,7 +922,7 @@ int ad7606_probe(struct device *dev, int irq, void __iomem *base_address,
> > >       st->write_scale = ad7606_write_scale_hw;
> > >       st->write_os = ad7606_write_os_hw;
> > >
> > > -     ret = ad7606_sw_mode_setup(indio_dev);
> > > +     ret = ad7606_sw_mode_setup(indio_dev, id);
> > >       if (ret)
> > >               return ret;
> > >
> > > diff --git a/drivers/iio/adc/ad7606.h b/drivers/iio/adc/ad7606.h
> > > index 2113ad460c0f..6b0897aa2dc7 100644
> > > --- a/drivers/iio/adc/ad7606.h
> > > +++ b/drivers/iio/adc/ad7606.h
> > > @@ -22,7 +22,7 @@
> > >               .scan_type = {                                  \
> > >                       .sign = 's',                            \
> > >                       .realbits = (bits),                     \
> > > -                     .storagebits = (bits),                  \
> > > +                     .storagebits = (bits) > 16 ? 32 : 16,   \
> > >                       .endianness = IIO_CPU,                  \
> > >               },                                              \
> > >  }
> > > @@ -45,7 +45,7 @@
> > >               .scan_type = {                                  \
> > >                       .sign = 's',                            \
> > >                       .realbits = (bits),                     \
> > > -                     .storagebits = (bits),                  \
> > > +                     .storagebits = (bits) > 16 ? 32 : 16,   \
> > >                       .endianness = IIO_CPU,                  \
> > >               },                                              \
> > >  }
> > > @@ -88,6 +88,8 @@ struct ad7606_chip_info {
> > >   *                   such that it can be read via the 'read_avail' hook
> > >   * @num_scales               number of elements stored in the scale_avail array
> > >   * @range            voltage range selection, selects which scale to apply
> > > + * @reg_offset               offset for the register value, to be applied when
> > > + *                   writing the value of 'range' to the register value
> > >   */
> > >  struct ad7606_chan_scale {
> > >  #define AD760X_MAX_SCALE_SHOW                (AD760X_MAX_CHANNELS * 2)
> > > @@ -95,6 +97,7 @@ struct ad7606_chan_scale {
> > >       int                             scale_avail_show[AD760X_MAX_SCALE_SHOW];
> > >       unsigned int                    num_scales;
> > >       unsigned int                    range;
> > > +     unsigned int                    reg_offset;
> > >  };
> > >
> > >  /**
> > > @@ -151,9 +154,13 @@ struct ad7606_state {
> > >       /*
> > >        * DMA (thus cache coherency maintenance) may require the
> > >        * transfer buffers to live in their own cache lines.
> > > -      * 16 * 16-bit samples + 64-bit timestamp
> > > +      * 16 * 16-bit samples + 64-bit timestamp - for AD7616
> > > +      * 8 * 32-bit samples + 64-bit timestamp - for AD7616C-18 (and similar)
> > >        */
> > > -     unsigned short                  data[20] __aligned(IIO_DMA_MINALIGN);
> > > +     union {
> > > +             unsigned short d16[20];
> > > +             unsigned int d32[10];
> > > +     } data __aligned(IIO_DMA_MINALIGN);
> > >       __be16                          d16[2];
> > >  };
> > >
> > > @@ -192,6 +199,8 @@ enum ad7606_supported_device_ids {
> > >       ID_AD7606_6,
> > >       ID_AD7606_4,
> > >       ID_AD7606B,
> > > +     ID_AD7606C_16,
> > > +     ID_AD7606C_18,
> > >       ID_AD7616,
> > >  };
> > >
> > > diff --git a/drivers/iio/adc/ad7606_spi.c b/drivers/iio/adc/ad7606_spi.c
> > > index e00f58a6a0e9..b8d630ad156d 100644
> > > --- a/drivers/iio/adc/ad7606_spi.c
> > > +++ b/drivers/iio/adc/ad7606_spi.c
> > > @@ -77,6 +77,18 @@ static const struct iio_chan_spec ad7606b_sw_channels[] = {
> > >       AD7606_SW_CHANNEL(7, 16),
> > >  };
> > >
> > > +static const struct iio_chan_spec ad7606c_18_sw_channels[] = {
> > > +     IIO_CHAN_SOFT_TIMESTAMP(8),
> > > +     AD7606_SW_CHANNEL(0, 18),
> > > +     AD7606_SW_CHANNEL(1, 18),
> > > +     AD7606_SW_CHANNEL(2, 18),
> > > +     AD7606_SW_CHANNEL(3, 18),
> > > +     AD7606_SW_CHANNEL(4, 18),
> > > +     AD7606_SW_CHANNEL(5, 18),
> > > +     AD7606_SW_CHANNEL(6, 18),
> > > +     AD7606_SW_CHANNEL(7, 18),
> > > +};
> > > +
> > >  static const unsigned int ad7606B_oversampling_avail[9] = {
> > >       1, 2, 4, 8, 16, 32, 64, 128, 256
> > >  };
> > > @@ -120,6 +132,19 @@ static int ad7606_spi_read_block(struct device *dev,
> > >       return 0;
> > >  }
> > >
> > > +static int ad7606_spi_read_block18to32(struct device *dev,
> > > +                                    int count, void *buf)
> > > +{
> > > +     struct spi_device *spi = to_spi_device(dev);
> > > +     struct spi_transfer xfer = {
> > > +             .bits_per_word = 18,
> > > +             .len = count,
> >
> > Isn't count the number of words? .len needs to be the number
> > of bytes, so 4 * count.
>
> Oh.
> Hmm, I need to check.
> I assumed .len is the count of elements, not of bytes.
>
> >
> > > +             .rx_buf = buf,
> > > +     };
> > > +
> > > +     return spi_sync_transfer(spi, &xfer, 1);
> > > +}
> > > +
> > >  static int ad7606_spi_reg_read(struct ad7606_state *st, unsigned int addr)
> > >  {
> > >       struct spi_device *spi = to_spi_device(st->dev);
> > > @@ -283,6 +308,19 @@ static int ad7606B_sw_mode_config(struct iio_dev *indio_dev)
> > >       return 0;
> > >  }
> > >
> > > +static int ad7606c_18_sw_mode_config(struct iio_dev *indio_dev)
> > > +{
> > > +     int ret;
> > > +
> > > +     ret = ad7606B_sw_mode_config(indio_dev);
> > > +     if (ret)
> > > +             return ret;
> > > +
> > > +     indio_dev->channels = ad7606c_18_sw_channels;
> > > +
> > > +     return 0;
> > > +}
> > > +
> > >  static const struct ad7606_bus_ops ad7606_spi_bops = {
> > >       .read_block = ad7606_spi_read_block,
> > >  };
> > > @@ -305,6 +343,15 @@ static const struct ad7606_bus_ops ad7606B_spi_bops = {
> > >       .sw_mode_config = ad7606B_sw_mode_config,
> > >  };
> > >
> > > +static const struct ad7606_bus_ops ad7606c_18_spi_bops = {
> > > +     .read_block = ad7606_spi_read_block18to32,
> > > +     .reg_read = ad7606_spi_reg_read,
> > > +     .reg_write = ad7606_spi_reg_write,
> > > +     .write_mask = ad7606_spi_write_mask,
> > > +     .rd_wr_cmd = ad7606B_spi_rd_wr_cmd,
> > > +     .sw_mode_config = ad7606c_18_sw_mode_config,
> > > +};
> > > +
> > >  static int ad7606_spi_probe(struct spi_device *spi)
> > >  {
> > >       const struct spi_device_id *id = spi_get_device_id(spi);
> > > @@ -315,8 +362,12 @@ static int ad7606_spi_probe(struct spi_device *spi)
> > >               bops = &ad7616_spi_bops;
> > >               break;
> > >       case ID_AD7606B:
> > > +     case ID_AD7606C_16:
> > >               bops = &ad7606B_spi_bops;
> > >               break;
> > > +     case ID_AD7606C_18:
> > > +             bops = &ad7606c_18_spi_bops;
> > > +             break;
> > >       default:
> > >               bops = &ad7606_spi_bops;
> > >               break;
> > > @@ -333,6 +384,8 @@ static const struct spi_device_id ad7606_id_table[] = {
> > >       { "ad7606-6", ID_AD7606_6 },
> > >       { "ad7606-8", ID_AD7606_8 },
> > >       { "ad7606b",  ID_AD7606B },
> > > +     { "ad7606c-16",  ID_AD7606C_16 },
> > > +     { "ad7606c-18",  ID_AD7606C_18 },
> > >       { "ad7616",   ID_AD7616 },
> > >       { }
> > >  };
> > > @@ -344,6 +397,8 @@ static const struct of_device_id ad7606_of_match[] = {
> > >       { .compatible = "adi,ad7606-6" },
> > >       { .compatible = "adi,ad7606-8" },
> > >       { .compatible = "adi,ad7606b" },
> > > +     { .compatible = "adi,ad7606c-16" },
> > > +     { .compatible = "adi,ad7606c-18" },
> > >       { .compatible = "adi,ad7616" },
> > >       { }
> > >  };
> >





[Index of Archives]     [Device Tree Compilter]     [Device Tree Spec]     [Linux Driver Backports]     [Video for Linux]     [Linux USB Devel]     [Linux PCI Devel]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [XFree86]     [Yosemite Backpacking]


  Powered by Linux