Hi Jonathan, Thanks for the review. I'll send a v2 soon.
On 10/14, Jonathan Cameron wrote: > On Sun, 13 Oct 2019 11:13:22 -0300 > Marcelo Schmitt <marcelo.schmi...@gmail.com> wrote: > > > The AD7292 is a 10-bit monitor and control system with ADC, DACs, > > temperature sensor, and GPIOs. > > > > Configure AD7292 devices in direct access mode, enabling single-ended > > ADC readings. > > > > Datasheet: > > Link: > > https://www.analog.com/media/en/technical-documentation/data-sheets/ad7292.pdf > > > > Signed-off-by: Marcelo Schmitt <marcelo.schmi...@gmail.com> > Hi Marcelo > > A few minor bits inline. Mostly just the DT binding question. > > Thanks, > > Jonathan > > > --- > > MAINTAINERS | 7 + > > drivers/iio/adc/Kconfig | 10 ++ > > drivers/iio/adc/Makefile | 1 + > > drivers/iio/adc/ad7292.c | 350 +++++++++++++++++++++++++++++++++++++++ > > 4 files changed, 368 insertions(+) > > create mode 100644 drivers/iio/adc/ad7292.c > > > > diff --git a/MAINTAINERS b/MAINTAINERS > > index 32bf5f8116d0..e78317a5f4f1 100644 > > --- a/MAINTAINERS > > +++ b/MAINTAINERS > > @@ -813,6 +813,13 @@ S: Supported > > F: drivers/iio/adc/ad7124.c > > F: Documentation/devicetree/bindings/iio/adc/adi,ad7124.txt > > > > +ANALOG DEVICES INC AD7292 DRIVER > > +M: Marcelo Schmitt <marcelo.schmi...@gmail.com> > > +L: linux-...@vger.kernel.org > > +W: http://ez.analog.com/community/linux-device-drivers > > +S: Supported > > +F: drivers/iio/adc/ad7292.c > > + > > ANALOG DEVICES INC AD7606 DRIVER > > M: Stefan Popa <stefan.p...@analog.com> > > L: linux-...@vger.kernel.org > > diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig > > index 632b331429c6..02587c990cb5 100644 > > --- a/drivers/iio/adc/Kconfig > > +++ b/drivers/iio/adc/Kconfig > > @@ -59,6 +59,16 @@ config AD7291 > > To compile this driver as a module, choose M here: the > > module will be called ad7291. > > > > +config AD7292 > > + tristate "Analog Devices AD7292 ADC driver" > > + depends on SPI > > + help > > + Say yes here to build support for Analog Devices AD7292 > > + 8 Channel ADC with temperature sensor. > > + > > + To compile this driver as a module, choose M here: the > > + module will be called ad7292. > > + > > config AD7298 > > tristate "Analog Devices AD7298 ADC driver" > > depends on SPI > > diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile > > index 4779ab3ff8fb..1818f2f66566 100644 > > --- a/drivers/iio/adc/Makefile > > +++ b/drivers/iio/adc/Makefile > > @@ -11,6 +11,7 @@ obj-$(CONFIG_AD7124) += ad7124.o > > obj-$(CONFIG_AD7173) += ad7173.o > > obj-$(CONFIG_AD7266) += ad7266.o > > obj-$(CONFIG_AD7291) += ad7291.o > > +obj-$(CONFIG_AD7292) += ad7292.o > > obj-$(CONFIG_AD7298) += ad7298.o > > obj-$(CONFIG_AD738X) += ad738x.o > > obj-$(CONFIG_AD7768) += ad7768-1.o > > diff --git a/drivers/iio/adc/ad7292.c b/drivers/iio/adc/ad7292.c > > new file mode 100644 > > index 000000000000..076bd49a2571 > > --- /dev/null > > +++ b/drivers/iio/adc/ad7292.c > > @@ -0,0 +1,350 @@ > > +// SPDX-License-Identifier: GPL-2.0 > > +/* > > + * Analog Devices AD7292 SPI ADC driver > > + * > > + * Copyright 2019 Analog Devices Inc. > > + */ > > + > > +#include <linux/bitfield.h> > > +#include <linux/device.h> > > +#include <linux/module.h> > > +#include <linux/regulator/consumer.h> > > +#include <linux/spi/spi.h> > > + > > +#include <linux/iio/iio.h> > > + > > +#define ADI_VENDOR_ID 0x0018 > > + > > +/* AD7292 registers definition */ > > +#define AD7292_REG_VENDOR_ID 0x00 > > +#define AD7292_REG_CONF_BANK 0x05 > > +#define AD7292_REG_CONV_COMM 0x0E > > +#define AD7292_REG_ADC_CH(x) (0x10 + (x)) > > + > > +/* AD7292 configuration bank subregisters definition */ > > +#define AD7292_BANK_REG_VIN_RNG0 0x10 > > +#define AD7292_BANK_REG_VIN_RNG1 0x11 > > +#define AD7292_BANK_REG_SAMP_MODE 0x12 > > + > > +#define AD7292_RD_FLAG_MSK(x) (BIT(7) | ((x) & 0x3F)) > > + > > +/* AD7292_REG_ADC_CONVERSION */ > > +#define AD7292_ADC_DATA_MASK GENMASK(15, 6) > > +#define AD7292_ADC_DATA(x) FIELD_GET(AD7292_ADC_DATA_MASK, x) > > + > > +/* AD7292_CHANNEL_SAMPLING_MODE */ > > +#define AD7292_CH_SAMP_MODE(reg, ch) ((reg >> 8) & BIT(ch)) > > + > > +/* AD7292_CHANNEL_VIN_RANGE */ > > +#define AD7292_CH_VIN_RANGE(reg, ch) (reg & BIT(ch)) > > + > > +#define AD7291_VOLTAGE_CHAN(_chan) \ > > +{ \ > > + .type = IIO_VOLTAGE, \ > > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ > > + BIT(IIO_CHAN_INFO_SCALE), \ > > + .indexed = 1, \ > > + .channel = _chan, \ > > +} > > + > > +static const struct iio_chan_spec ad7292_channels[] = { > > + AD7291_VOLTAGE_CHAN(0), > > + AD7291_VOLTAGE_CHAN(1), > > + AD7291_VOLTAGE_CHAN(2), > > + AD7291_VOLTAGE_CHAN(3), > > + AD7291_VOLTAGE_CHAN(4), > > + AD7291_VOLTAGE_CHAN(5), > > + AD7291_VOLTAGE_CHAN(6), > > + AD7291_VOLTAGE_CHAN(7) > > +}; > > + > > +static const struct iio_chan_spec ad7292_channels_diff[] = { > > + { > > + .type = IIO_VOLTAGE, > > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), > > + .indexed = 1, > > + .differential = 1, > > + .channel = 0, > > + .channel2 = 1, > > + }, > > + AD7291_VOLTAGE_CHAN(2), > > + AD7291_VOLTAGE_CHAN(3), > > + AD7291_VOLTAGE_CHAN(4), > > + AD7291_VOLTAGE_CHAN(5), > > + AD7291_VOLTAGE_CHAN(6), > > + AD7291_VOLTAGE_CHAN(7) > > +}; > > + > > +struct ad7292_state { > > + struct spi_device *spi; > > + struct regulator *reg; > > + unsigned short vref_mv; > > + union { > > + __be16 d16; > > + u8 d8[2]; > > + } data ____cacheline_aligned; > > Given it is a whole cacheline long anyway, I'd be tempted to just have > these as separate fields. > > > +}; > > + > > +static int ad7292_spi_reg_read(struct ad7292_state *st, unsigned int addr) > > +{ > > + int ret; > > + > > + st->data.d8[0] = AD7292_RD_FLAG_MSK(addr); > > + > > + ret = spi_write_then_read(st->spi, st->data.d8, 1, &st->data.d16, 2); > > + if (ret < 0) > > + return ret; > > + > > + return be16_to_cpu(st->data.d16); > > +} > > + > > +static int ad7292_spi_subreg_read(struct ad7292_state *st, unsigned int > > addr, > > + unsigned int sub_addr, unsigned int len) > > +{ > > + unsigned int shift = 16 - (8 * len); > > + int ret; > > + > > + st->data.d8[0] = AD7292_RD_FLAG_MSK(addr); > > + st->data.d8[1] = sub_addr; > > + > > + ret = spi_write_then_read(st->spi, st->data.d8, 2, &st->data.d16, len); > > + if (ret < 0) > > + return ret; > > + > > + return (be16_to_cpu(st->data.d16) >> shift); > > +} > > + > > +static int ad7292_single_conversion(struct ad7292_state *st, > > + unsigned int chan_addr) > > +{ > > + int ret; > > + > > + struct spi_transfer t[] = { > > + { > > + .tx_buf = &st->data, > > + .len = 4, > > + .delay_usecs = 6, > > + }, { > > + .rx_buf = &st->data.d16, > > + .len = 2, > > + }, > > + }; > > + > > + st->data.d8[0] = chan_addr; > > + st->data.d8[1] = AD7292_RD_FLAG_MSK(AD7292_REG_CONV_COMM); > > + > > + ret = spi_sync_transfer(st->spi, t, ARRAY_SIZE(t)); > > + > > + if (ret < 0) > > + return ret; > > + > > + return be16_to_cpu(st->data.d16); > > +} > > + > > +static int ad7292_vin_range_multiplier(struct ad7292_state *st, int > > channel) > > +{ > > + int samp_mode, range0, range1; > > + int factor = 1; > > + > > + /* > > + * Every AD7292 ADC channel may have its input range adjusted according > > + * to the settings at the ADC sampling mode and VIN range subregisters. > > + * For a given channel, the minimum input range is equal to Vref, and it > > + * may be increased by a multiplier factor of 2 or 4 according to the > > + * following rule: > > + * If channel is being sampled wiht respect to AGND: > > + * factor = 4 if VIN range0 and VIN range1 equal 0 > > + * factor = 2 if only one of VIN ranges equal 1 > > + * factor = 1 if both VIN range0 and VIN range1 equal 1 > > + * If channel is being sampled with respect to AVDD: > > + * factor = 4 if VIN range0 and VIN range1 equal 0 > > + * Behavior is undefined if any of VIN range doesn't equal 0 > > + */ > > + > > + samp_mode = ad7292_spi_subreg_read(st, AD7292_REG_CONF_BANK, > > + AD7292_BANK_REG_SAMP_MODE, 2); > > + > > + if (samp_mode < 0) > > + return samp_mode; > > + > > + range0 = ad7292_spi_subreg_read(st, AD7292_REG_CONF_BANK, > > + AD7292_BANK_REG_VIN_RNG0, 2); > > + > > + if (range0 < 0) > > + return range0; > > + > > + range1 = ad7292_spi_subreg_read(st, AD7292_REG_CONF_BANK, > > + AD7292_BANK_REG_VIN_RNG1, 2); > > + > > + if (range1 < 0) > > + return range1; > > + > > + if (AD7292_CH_SAMP_MODE(samp_mode, channel)) { > > + /* Sampling with respect to AGND */ > > + if (!AD7292_CH_VIN_RANGE(range0, channel)) > > + factor *= 2; > > + > > + if (!AD7292_CH_VIN_RANGE(range1, channel)) > > + factor *= 2; > > + > > + } else { > > + /* Sampling with respect to AVDD */ > > + if (AD7292_CH_VIN_RANGE(range0, channel) || > > + AD7292_CH_VIN_RANGE(range1, channel)) > > + return -EPERM; > > + > > + factor = 4; > > + } > > + > > + return factor; > > +} > > + > > +static int ad7292_read_raw(struct iio_dev *indio_dev, > > + const struct iio_chan_spec *chan, > > + int *val, int *val2, long info) > > +{ > > + struct ad7292_state *st = iio_priv(indio_dev); > > + unsigned int ch_addr; > > + int ret; > > + > > + switch (info) { > > + case IIO_CHAN_INFO_RAW: > > + ch_addr = AD7292_REG_ADC_CH(chan->channel); > > + ret = ad7292_single_conversion(st, ch_addr); > > + if (ret < 0) > > + return ret; > > + > > + *val = AD7292_ADC_DATA(ret); > > + > > + return IIO_VAL_INT; > > + case IIO_CHAN_INFO_SCALE: > > + /* > > + * To convert a raw value to standard units, the IIO defines > > + * this formula: Scaled value = (raw + offset) * scale. > > + * For the scale to be a correct multiplier for (raw + offset), > > + * it must be calculated as the input range divided by the > > + * number of possible distinct input values. Given the ADC data > > + * is 10 bit long, it may assume only 2^10 distinct values. > > + * Hence, scale = range / 2^10. The IIO_VAL_FRACTIONAL_LOG2 > > + * return type indicates to the IIO API to divide *val by 2 to > > + * the power of *val2 when returning from read_raw. > > + */ > > + > > + *val = regulator_get_voltage(st->reg); > > + if (*val < 0) > > + *val = st->vref_mv; > > + else > > + *val /= 1000; > > + > > + ret = ad7292_vin_range_multiplier(st, chan->channel); > > + if (ret < 0) > > + return ret; > > + > > + *val *= ret; > > + *val2 = 10; > > + return IIO_VAL_FRACTIONAL_LOG2; > > + default: > > + break; > > + } > > + return -EINVAL; > > +} > > + > > +static const struct iio_info ad7292_info = { > > + .read_raw = ad7292_read_raw, > > +}; > > + > > +static void ad7292_regulator_disable(void *data) > > +{ > > + struct ad7292_state *st = data; > > + > > + regulator_disable(st->reg); > > +} > > + > > +static int ad7292_probe(struct spi_device *spi) > > +{ > > + struct ad7292_state *st; > > + struct iio_dev *indio_dev; > > + int ret; > > + > > + indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); > > + if (!indio_dev) > > + return -ENOMEM; > > + > > + st = iio_priv(indio_dev); > > + st->spi = spi; > > + > > + ret = ad7292_spi_reg_read(st, AD7292_REG_VENDOR_ID); > > + if (ret != ADI_VENDOR_ID) { > > + dev_err(&spi->dev, "Wrong vendor id 0x%x\n", ret); > > + return -EINVAL; > > + } > > + > > + spi_set_drvdata(spi, indio_dev); > > + > > + st->reg = devm_regulator_get_optional(&spi->dev, "vref"); > > + if (!IS_ERR(st->reg)) { > > + ret = regulator_enable(st->reg); > > + if (ret) { > > + dev_err(&spi->dev, > > + "Failed to enable external vref supply\n"); > > + return ret; > > + } > > + > > + ret = devm_add_action_or_reset(&spi->dev, > > + ad7292_regulator_disable, st); > > + if (ret) { > > + regulator_disable(st->reg); > > + return ret; > > + } > > + > > + ret = regulator_get_voltage(st->reg); > > + if (ret < 0) > > + return ret; > > We get the voltage here, but then I think we throw it away by rereading it > each time above. No need to get it in both places. > > > + > > + st->vref_mv = ret / 1000; > > + } else { > > Perhaps add a comment here to say this is the internal reference. > > > + st->vref_mv = 1250; > > + } > > + > > + indio_dev->dev.parent = &spi->dev; > > + indio_dev->name = spi_get_device_id(spi)->name; > > + indio_dev->modes = INDIO_DIRECT_MODE; > > + indio_dev->info = &ad7292_info; > > + > > + ret = of_property_read_bool(spi->dev.of_node, "diff-channels"); > > I mention in review of the dt patch that this should use the generic > binding support for specifying differential channels. > > > + if (ret) { > > + indio_dev->num_channels = ARRAY_SIZE(ad7292_channels_diff); > > + indio_dev->channels = ad7292_channels_diff; > > + } else { > > + indio_dev->num_channels = ARRAY_SIZE(ad7292_channels); > > + indio_dev->channels = ad7292_channels; > > + } > > + > > + return devm_iio_device_register(&spi->dev, indio_dev); > > +} > > + > > +static const struct spi_device_id ad7292_id_table[] = { > > + { "ad7292", 0 }, > > + {} > > +}; > > +MODULE_DEVICE_TABLE(spi, ad7292_id_table); > > + > > +static const struct of_device_id ad7292_of_match[] = { > > + { .compatible = "adi,ad7292" }, > > + { }, > > +}; > > +MODULE_DEVICE_TABLE(of, ad7292_of_match); > > + > > +static struct spi_driver ad7292_driver = { > > + .driver = { > > + .name = "ad7292", > > + .of_match_table = ad7292_of_match, > > + }, > > + .probe = ad7292_probe, > > + .id_table = ad7292_id_table, > > +}; > > +module_spi_driver(ad7292_driver); > > + > > +MODULE_AUTHOR("Marcelo Schmitt <marcelo.schmi...@gmail.com>"); > > +MODULE_DESCRIPTION("Analog Devices AD7292 ADC driver"); > > +MODULE_LICENSE("GPL v2"); > >
