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