On 10/1/24 10:26, Alexandru Ardelean wrote:
On Thu, Sep 19, 2024 at 4:05 PM Alexandru Ardelean <aardelean@xxxxxxxxxxxx> 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: https://www.analog.com/media/en/technical-documentation/data-sheets/ad7606c-16.pdf Datasheet: 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 | 263 +++++++++++++++++++++++++++++++++-- drivers/iio/adc/ad7606.h | 16 ++- drivers/iio/adc/ad7606_spi.c | 55 ++++++++ 3 files changed, 322 insertions(+), 12 deletions(-) diff --git a/drivers/iio/adc/ad7606.c b/drivers/iio/adc/ad7606.c index b909ee14fd81..f04e5660d2f8 100644 --- a/drivers/iio/adc/ad7606.c +++ b/drivers/iio/adc/ad7606.c @@ -36,6 +36,33 @@ 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_16bit_single_ended_unipolar_scale_avail[3] = { + 76294, 152588, 190735, +}; + +static const unsigned int ad7606c_16bit_single_ended_bipolar_scale_avail[5] = { + 76294, 152588, 190735, 305176, 381470 +}; + +static const unsigned int ad7606c_16bit_differential_bipolar_scale_avail[4] = { + 152588, 305176, 381470, 610352 +}; + +static const unsigned int ad7606c_18bit_single_ended_unipolar_scale_avail[3] = { + 19073, 38147, 47684 +}; + +static const unsigned int ad7606c_18bit_single_ended_bipolar_scale_avail[5] = { + 19073, 38147, 47684, 76294, 95367 +}; + +static const unsigned int ad7606c_18bit_differential_bipolar_scale_avail[4] = { + 38147, 76294, 95367, 152588 +}; static const unsigned int ad7606_16bit_sw_scale_avail[3] = { 76293, 152588, 305176 @@ -62,7 +89,8 @@ int ad7606_reset(struct ad7606_state *st) } EXPORT_SYMBOL_NS_GPL(ad7606_reset, IIO_AD7606); -static int ad7606_16bit_chan_scale_setup(struct ad7606_state *st, int ch) +static int ad7606_16bit_chan_scale_setup(struct ad7606_state *st, + struct iio_chan_spec *chan, int ch) { struct ad7606_chan_scale *cs = &st->chan_scales[ch]; @@ -83,6 +111,173 @@ static int ad7606_16bit_chan_scale_setup(struct ad7606_state *st, int ch) return 0; } +static int ad7606_get_chan_config(struct ad7606_state *st, int ch, + bool *bipolar, bool *differential) +{ + unsigned int num_channels = st->chip_info->num_channels - 1; + struct device *dev = st->dev; + int ret; + + *bipolar = false; + *differential = false; + + device_for_each_child_node_scoped(dev, child) { + u32 pins[2]; + int reg; + + ret = fwnode_property_read_u32(child, "reg", ®); + if (ret) + continue; + + /* channel number (here) is from 1 to num_channels */ + if (reg == 0 || reg > num_channels) { + dev_warn(dev, + "Invalid channel number (ignoring): %d\n", reg); + continue; + } + + if (reg != (ch + 1)) + continue; + + *bipolar = fwnode_property_read_bool(child, "bipolar"); + + 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] != reg || pins[1] != reg)) { + dev_err(dev, + "Differential pins must be the same as 'reg'"); + return -EINVAL; + } + + *differential = (ret == 0); + + if (*differential && !*bipolar) { + dev_err(dev, + "'bipolar' must be added for diff channel %d\n", + reg); + return -EINVAL; + } + + return 0; + } + + return 0; +} + +static int ad7606c_18bit_chan_scale_setup(struct ad7606_state *st, + struct iio_chan_spec *chan, int ch) +{ + struct ad7606_chan_scale *cs = &st->chan_scales[ch]; + bool bipolar, differential; + int ret; + + if (!st->sw_mode_en) { + cs->range = 0; + cs->scale_avail = ad7606_18bit_hw_scale_avail; + cs->num_scales = ARRAY_SIZE(ad7606_18bit_hw_scale_avail); + return 0; + } + + ret = ad7606_get_chan_config(st, ch, &bipolar, &differential); + if (ret) + return ret; + + if (differential) { + cs->scale_avail = ad7606c_18bit_differential_bipolar_scale_avail; + cs->num_scales = + ARRAY_SIZE(ad7606c_18bit_differential_bipolar_scale_avail); + /* Bipolar differential ranges start at 8 (b1000) */ + cs->reg_offset = 8; + cs->range = 1; + chan->differential = 1; + chan->channel2 = chan->channel; + + return 0; + } + + chan->differential = 0; + + if (bipolar) { + cs->scale_avail = ad7606c_18bit_single_ended_bipolar_scale_avail; + cs->num_scales = + ARRAY_SIZE(ad7606c_18bit_single_ended_bipolar_scale_avail); + /* Bipolar single-ended ranges start at 0 (b0000) */ + cs->reg_offset = 0; + cs->range = 3; + chan->scan_type.sign = 's'; + + return 0; + } + + cs->scale_avail = ad7606c_18bit_single_ended_unipolar_scale_avail; + cs->num_scales = + ARRAY_SIZE(ad7606c_18bit_single_ended_unipolar_scale_avail); + /* Unipolar single-ended ranges start at 5 (b0101) */ + cs->reg_offset = 5; + cs->range = 1; + chan->scan_type.sign = 'u'; + + return 0; +} + +static int ad7606c_16bit_chan_scale_setup(struct ad7606_state *st, + struct iio_chan_spec *chan, int ch) +{ + struct ad7606_chan_scale *cs = &st->chan_scales[ch]; + bool bipolar, differential; + int ret; + + if (!st->sw_mode_en) { + cs->range = 0; + cs->scale_avail = ad7606_16bit_hw_scale_avail; + cs->num_scales = ARRAY_SIZE(ad7606_16bit_hw_scale_avail); + return 0; + } + + ret = ad7606_get_chan_config(st, ch, &bipolar, &differential); + if (ret) + return ret; + + if (differential) { + cs->scale_avail = ad7606c_16bit_differential_bipolar_scale_avail; + cs->num_scales = + ARRAY_SIZE(ad7606c_16bit_differential_bipolar_scale_avail); + /* Bipolar differential ranges start at 8 (b1000) */ + cs->reg_offset = 8; + cs->range = 1; + chan->differential = 1; + chan->channel2 = chan->channel; + chan->scan_type.sign = 's'; + + return 0; + } + + chan->differential = 0; + + if (bipolar) { + cs->scale_avail = ad7606c_16bit_single_ended_bipolar_scale_avail; + cs->num_scales = + ARRAY_SIZE(ad7606c_16bit_single_ended_bipolar_scale_avail); + /* Bipolar single-ended ranges start at 0 (b0000) */ + cs->reg_offset = 0; + cs->range = 3; + chan->scan_type.sign = 's'; + + return 0; + } + + cs->scale_avail = ad7606c_16bit_single_ended_unipolar_scale_avail; + cs->num_scales = + ARRAY_SIZE(ad7606c_16bit_single_ended_unipolar_scale_avail); + /* Unipolar single-ended ranges start at 5 (b0101) */ + cs->reg_offset = 5; + cs->range = 1; + chan->scan_type.sign = 'u'; + + return 0; +} + static int ad7606_reg_access(struct iio_dev *indio_dev, unsigned int reg, unsigned int writeval, @@ -107,9 +302,8 @@ static int ad7606_reg_access(struct iio_dev *indio_dev, static int ad7606_read_samples(struct ad7606_state *st) { unsigned int num = st->chip_info->num_channels - 1; - u16 *data = st->data; - return st->bops->read_block(st->dev, num, data); + return st->bops->read_block(st->dev, num, &st->data); } static irqreturn_t ad7606_trigger_handler(int irq, void *p) @@ -125,7 +319,7 @@ static irqreturn_t ad7606_trigger_handler(int irq, void *p) 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, iio_get_time_ns(indio_dev)); error_ret: iio_trigger_notify_done(indio_dev->trig); @@ -139,6 +333,8 @@ 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; + const struct iio_chan_spec *chan; int ret; gpiod_set_value(st->gpio_convst, 1); @@ -153,7 +349,19 @@ static int ad7606_scan_direct(struct iio_dev *indio_dev, unsigned int ch, if (ret) goto error_ret; - *val = sign_extend32(st->data[ch], 15); + chan = &indio_dev->channels[ch + 1]; + if (chan->scan_type.sign == 'u') { + if (storagebits > 16) + *val = st->data.buf32[ch]; + else + *val = st->data.buf16[ch]; + return 0;Arrggh... I messed up here. Guillaume found a bug here, where this should be "goto error_ret" or do an "if () {} else {}" How should we do it here? Do we send a fix-patch or send a new series?
I can also send a fix in my next version of the "Add iio backend support" series which depends on this one.
+ } + + if (storagebits > 16) + *val = sign_extend32(st->data.buf32[ch], 17); + else + *val = sign_extend32(st->data.buf16[ch], 15); error_ret: gpiod_set_value(st->gpio_convst, 0); @@ -266,7 +474,7 @@ 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; @@ -349,6 +557,18 @@ 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. @@ -414,6 +634,20 @@ 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, + .scale_setup_cb = ad7606c_16bit_chan_scale_setup, + .oversampling_avail = ad7606_oversampling_avail, + .oversampling_num = ARRAY_SIZE(ad7606_oversampling_avail), + }, + [ID_AD7606C_18] = { + .channels = ad7606_channels_18bit, + .num_channels = 9, + .scale_setup_cb = ad7606c_18bit_chan_scale_setup, + .oversampling_avail = ad7606_oversampling_avail, + .oversampling_num = ARRAY_SIZE(ad7606_oversampling_avail), + }, [ID_AD7616] = { .channels = ad7616_channels, .num_channels = 17, @@ -586,7 +820,7 @@ 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 int ad7606_sw_mode_setup(struct iio_dev *indio_dev, unsigned int id) { struct ad7606_state *st = iio_priv(indio_dev); @@ -604,13 +838,24 @@ static int ad7606_chan_scales_setup(struct iio_dev *indio_dev) { unsigned int num_channels = indio_dev->num_channels - 1; struct ad7606_state *st = iio_priv(indio_dev); + struct iio_chan_spec *chans; + size_t size; int ch, ret; + /* Clone IIO channels, since some may be differential */ + size = indio_dev->num_channels * sizeof(*indio_dev->channels); + chans = devm_kzalloc(st->dev, size, GFP_KERNEL); + if (!chans) + return -ENOMEM; + + memcpy(chans, indio_dev->channels, size); + indio_dev->channels = chans; + for (ch = 0; ch < num_channels; ch++) { struct ad7606_chan_scale *cs; int i; - ret = st->chip_info->scale_setup_cb(st, ch); + ret = st->chip_info->scale_setup_cb(st, &chans[ch + 1], ch); if (ret) return ret; @@ -698,7 +943,7 @@ 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 25e84efd15c3..14ee75aa225b 100644 --- a/drivers/iio/adc/ad7606.h +++ b/drivers/iio/adc/ad7606.h @@ -63,7 +63,8 @@ struct ad7606_state; -typedef int (*ad7606_scale_setup_cb_t)(struct ad7606_state *st, int ch); +typedef int (*ad7606_scale_setup_cb_t)(struct ad7606_state *st, + struct iio_chan_spec *chan, int ch); /** * struct ad7606_chip_info - chip specific information @@ -94,6 +95,8 @@ 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_SCALES 16 @@ -102,6 +105,7 @@ struct ad7606_chan_scale { int scale_avail_show[AD760X_MAX_SCALE_SHOW]; unsigned int num_scales; unsigned int range; + unsigned int reg_offset; }; /** @@ -158,9 +162,13 @@ 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 { + u16 buf16[20]; + u32 buf32[10]; + } data __aligned(IIO_DMA_MINALIGN); __be16 d16[2]; }; @@ -201,6 +209,8 @@ 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..143440e73aab 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 * sizeof(u32), + .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" }, { } }; -- 2.46.0
