On Wed, 14 Jun 2023 12:11:55 +0300 Andy Shevchenko <andy.shevchenko@xxxxxxxxx> wrote: > On Wed, Jun 14, 2023 at 3:49 AM Kim Seer Paller > <kimseer.paller@xxxxxxxxxx> wrote: > > > > The MAX14001 is configurable, isolated 10-bit ADCs for multi-range > > binary inputs. > > Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx> > One question below. > > > Signed-off-by: Kim Seer Paller <kimseer.paller@xxxxxxxxxx> > > --- > > V5 -> V6: Replaced fixed length assignment with dynamic size > > assignment in xfers struct initialization. Removed .channel > > assignment in max14001_channels definition. > > V4 -> V5: No changes. > > V3 -> V4: Removed regmap setup, structures, and include. > > > > MAINTAINERS | 1 + > > drivers/iio/adc/Kconfig | 10 ++ > > drivers/iio/adc/Makefile | 1 + > > drivers/iio/adc/max14001.c | 327 +++++++++++++++++++++++++++++++++++++ > > 4 files changed, 339 insertions(+) > > create mode 100644 drivers/iio/adc/max14001.c > > > > diff --git a/MAINTAINERS b/MAINTAINERS > > index dcea2c31f920..b527cf471d7a 100644 > > --- a/MAINTAINERS > > +++ b/MAINTAINERS > > @@ -12676,6 +12676,7 @@ L: linux-iio@xxxxxxxxxxxxxxx > > S: Supported > > W: https://ez.analog.com/linux-software-drivers > > F: Documentation/devicetree/bindings/iio/adc/adi,max14001.yaml > > +F: drivers/iio/adc/max14001.c > > > > MAXBOTIX ULTRASONIC RANGER IIO DRIVER > > M: Andreas Klinger <ak@xxxxxxxxxxxxx> > > diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig > > index eb2b09ef5d5b..e599d166e98d 100644 > > --- a/drivers/iio/adc/Kconfig > > +++ b/drivers/iio/adc/Kconfig > > @@ -706,6 +706,16 @@ config MAX11410 > > To compile this driver as a module, choose M here: the module will be > > called max11410. > > > > +config MAX14001 > > + tristate "Analog Devices MAX14001 ADC driver" > > + depends on SPI > > + help > > + Say yes here to build support for Analog Devices MAX14001 Configurable, > > + Isolated 10-bit ADCs for Multi-Range Binary Inputs. > > + > > + To compile this driver as a module, choose M here: the module will be > > + called max14001. > > + > > config MAX1241 > > tristate "Maxim max1241 ADC driver" > > depends on SPI_MASTER > > diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile > > index e07e4a3e6237..9f8964258f03 100644 > > --- a/drivers/iio/adc/Makefile > > +++ b/drivers/iio/adc/Makefile > > @@ -65,6 +65,7 @@ obj-$(CONFIG_MAX11100) += max11100.o > > obj-$(CONFIG_MAX1118) += max1118.o > > obj-$(CONFIG_MAX11205) += max11205.o > > obj-$(CONFIG_MAX11410) += max11410.o > > +obj-$(CONFIG_MAX14001) += max14001.o > > obj-$(CONFIG_MAX1241) += max1241.o > > obj-$(CONFIG_MAX1363) += max1363.o > > obj-$(CONFIG_MAX9611) += max9611.o > > diff --git a/drivers/iio/adc/max14001.c b/drivers/iio/adc/max14001.c > > new file mode 100644 > > index 000000000000..b4d10539398b > > --- /dev/null > > +++ b/drivers/iio/adc/max14001.c > > @@ -0,0 +1,327 @@ > > +// SPDX-License-Identifier: (GPL-2.0-only OR BSD-3-Clause) > > +/* > > + * Analog Devices MAX14001 ADC driver > > + * > > + * Copyright 2023 Analog Devices Inc. > > + */ > > + > > +#include <linux/bitfield.h> > > +#include <linux/bitrev.h> > > +#include <linux/device.h> > > +#include <linux/iio/iio.h> > > +#include <linux/kernel.h> > > +#include <linux/module.h> > > +#include <linux/mod_devicetable.h> > > +#include <linux/property.h> > > +#include <linux/regulator/consumer.h> > > +#include <linux/spi/spi.h> > > +#include <linux/slab.h> > > +#include <linux/types.h> > > + > > +#include <asm/unaligned.h> > > + > > +/* MAX14001 Registers Address */ > > +#define MAX14001_ADC 0x00 > > +#define MAX14001_FADC 0x01 > > +#define MAX14001_FLAGS 0x02 > > +#define MAX14001_FLTEN 0x03 > > +#define MAX14001_THL 0x04 > > +#define MAX14001_THU 0x05 > > +#define MAX14001_INRR 0x06 > > +#define MAX14001_INRT 0x07 > > +#define MAX14001_INRP 0x08 > > +#define MAX14001_CFG 0x09 > > +#define MAX14001_ENBL 0x0A > > +#define MAX14001_ACT 0x0B > > +#define MAX14001_WEN 0x0C > > + > > +#define MAX14001_VERIFICATION_REG(x) ((x) + 0x10) > > + > > +#define MAX14001_CFG_EXRF BIT(5) > > + > > +#define MAX14001_ADDR_MASK GENMASK(15, 11) > > +#define MAX14001_DATA_MASK GENMASK(9, 0) > > +#define MAX14001_FILTER_MASK GENMASK(3, 2) > > + > > +#define MAX14001_SET_WRITE_BIT BIT(10) > > +#define MAX14001_WRITE_WEN 0x294 > > + > > +struct max14001_state { > > + struct spi_device *spi; > > + /* > > + * lock protect against multiple concurrent accesses, RMW sequence, and > > + * SPI transfer > > + */ > > + struct mutex lock; > > + int vref_mv; > > + /* > > + * DMA (thus cache coherency maintenance) requires the > > + * transfer buffers to live in their own cache lines. > > + */ > > + __be16 spi_tx_buffer __aligned(IIO_DMA_MINALIGN); > > + __be16 spi_rx_buffer; > > +}; > > + > > +static int max14001_read(void *context, unsigned int reg_addr, unsigned int *data) > > +{ > > + struct max14001_state *st = context; > > + int ret; > > + > > + struct spi_transfer xfers[] = { > > + { > > + .tx_buf = &st->spi_tx_buffer, > > + .len = sizeof(st->spi_tx_buffer), > > + .cs_change = 1, > > + }, { > > + .rx_buf = &st->spi_rx_buffer, > > + .len = sizeof(st->spi_rx_buffer), > > + }, > > + }; > > + > > + st->spi_tx_buffer = bitrev16(cpu_to_be16(FIELD_PREP(MAX14001_ADDR_MASK, > > + reg_addr))); > > + > > + ret = spi_sync_transfer(st->spi, xfers, ARRAY_SIZE(xfers)); > > + if (ret) > > + return ret; > > + > > + *data = bitrev16(be16_to_cpu(st->spi_rx_buffer)) & MAX14001_DATA_MASK; > > + > > + return 0; > > +} > > + > > +static int max14001_write(void *context, unsigned int reg_addr, unsigned int data) > > +{ > > + struct max14001_state *st = context; > > + > > + st->spi_tx_buffer = bitrev16(cpu_to_be16( > > + FIELD_PREP(MAX14001_ADDR_MASK, reg_addr) | > > + FIELD_PREP(MAX14001_SET_WRITE_BIT, 1) | > > + FIELD_PREP(MAX14001_DATA_MASK, data))); > > + > > + return spi_write(st->spi, &st->spi_tx_buffer, sizeof(st->spi_tx_buffer)); > > +} > > + > > +static int max14001_write_verification_reg(struct max14001_state *st, > > + unsigned int reg_addr) > > +{ > > + unsigned int reg_data; > > + int ret; > > + > > + ret = max14001_read(st, reg_addr, ®_data); > > + if (ret) > > + return ret; > > + > > + return max14001_write(st, MAX14001_VERIFICATION_REG(reg_addr), reg_data); > > +} > > + > > +static int max14001_reg_update(struct max14001_state *st, > > + unsigned int reg_addr, > > + unsigned int mask, > > + unsigned int val) > > +{ > > + int ret; > > + unsigned int reg_data; > > + > > + /* Enable SPI Registers Write */ > > + ret = max14001_write(st, MAX14001_WEN, MAX14001_WRITE_WEN); > > + if (ret) > > + return ret; > > + > > + ret = max14001_read(st, reg_addr, ®_data); > > + if (ret) > > + return ret; > > + > > + reg_data = FIELD_PREP(mask, val); > > + > > + ret = max14001_write(st, reg_addr, reg_data); > > + if (ret) > > + return ret; > > + > > + /* Write Verification Register */ > > + ret = max14001_write_verification_reg(st, reg_addr); > > + if (ret) > > + return ret; > > + > > + /* Disable SPI Registers Write */ > > + return max14001_write(st, MAX14001_WEN, 0); > > +} > > + > > +static int max14001_read_raw(struct iio_dev *indio_dev, > > + struct iio_chan_spec const *chan, > > + int *val, int *val2, long mask) > > +{ > > + struct max14001_state *st = iio_priv(indio_dev); > > + unsigned int data; > > + int ret; > > + > > + switch (mask) { > > + case IIO_CHAN_INFO_RAW: > > + mutex_lock(&st->lock); > > + ret = max14001_read(st, MAX14001_ADC, &data); > > + mutex_unlock(&st->lock); > > + if (ret < 0) > > + return ret; > > + > > + *val = data; > > + > > + return IIO_VAL_INT; > > + > > + case IIO_CHAN_INFO_SCALE: > > + *val = st->vref_mv; > > + *val2 = 10; > > + > > + return IIO_VAL_FRACTIONAL_LOG2; > > + > > + default: > > + return -EINVAL; > > + } > > +} > > + > > +static const struct iio_info max14001_info = { > > + .read_raw = max14001_read_raw, > > +}; > > + > > +static const struct iio_chan_spec max14001_channels[] = { > > + { > > + .type = IIO_VOLTAGE, > > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | > > + BIT(IIO_CHAN_INFO_SCALE), > > + } > > +}; > > + > > +static void max14001_regulator_disable(void *data) > > +{ > > + struct regulator *reg = data; > > + > > + regulator_disable(reg); > > +} > > + > > +static int max14001_init(struct max14001_state *st) > > +{ > > + int ret; > > + > > + /* Enable SPI Registers Write */ > > + ret = max14001_write(st, MAX14001_WEN, MAX14001_WRITE_WEN); > > + if (ret) > > + return ret; > > + > > + /* > > + * Reads all registers and writes the values back to their appropriate > > + * verification registers to clear the Memory Validation fault. > > + */ > > + ret = max14001_write_verification_reg(st, MAX14001_FLTEN); > > + if (ret) > > + return ret; > > + > > + ret = max14001_write_verification_reg(st, MAX14001_THL); > > + if (ret) > > + return ret; > > + > > + ret = max14001_write_verification_reg(st, MAX14001_THU); > > + if (ret) > > + return ret; > > + > > + ret = max14001_write_verification_reg(st, MAX14001_INRR); > > + if (ret) > > + return ret; > > + > > + ret = max14001_write_verification_reg(st, MAX14001_INRT); > > + if (ret) > > + return ret; > > + > > + ret = max14001_write_verification_reg(st, MAX14001_INRP); > > + if (ret) > > + return ret; > > + > > + ret = max14001_write_verification_reg(st, MAX14001_CFG); > > + if (ret) > > + return ret; > > + > > + ret = max14001_write_verification_reg(st, MAX14001_ENBL); > > + if (ret) > > + return ret; > > + > > + /* Disable SPI Registers Write */ > > + return max14001_write(st, MAX14001_WEN, 0); > > +} > > + > > +static int max14001_probe(struct spi_device *spi) > > +{ > > + struct iio_dev *indio_dev; > > + struct max14001_state *st; > > + struct regulator *vref; > > + struct device *dev = &spi->dev; > > + int ret; > > + > > + indio_dev = devm_iio_device_alloc(dev, sizeof(*st)); > > + if (!indio_dev) > > + return -ENOMEM; > > + > > + st = iio_priv(indio_dev); > > + st->spi = spi; > > + > > + indio_dev->name = "max14001"; > > + indio_dev->info = &max14001_info; > > + indio_dev->channels = max14001_channels; > > + indio_dev->num_channels = ARRAY_SIZE(max14001_channels); > > + indio_dev->modes = INDIO_DIRECT_MODE; > > + > > + ret = max14001_init(st); > > + if (ret) > > + return ret; > > + > > + vref = devm_regulator_get_optional(dev, "vref"); > > + if (IS_ERR(vref)) { > > + if (PTR_ERR(vref) != -ENODEV) > > + return dev_err_probe(dev, PTR_ERR(vref), > > + "Failed to get vref regulator"); > > + > > + /* internal reference */ > > + st->vref_mv = 1250; > > + } else { > > + ret = regulator_enable(vref); > > + if (ret) > > + return dev_err_probe(dev, ret, > > + "Failed to enable vref regulators\n"); > > + > > + ret = devm_add_action_or_reset(dev, max14001_regulator_disable, > > + vref); > > + if (ret) > > + return ret; > > > + /* select external voltage reference source for the ADC */ > > + ret = max14001_reg_update(st, MAX14001_CFG, > > + MAX14001_CFG_EXRF, 1); > > + ret not checked. > > + ret = regulator_get_voltage(vref); > > + if (ret < 0) > > + return dev_err_probe(dev, ret, > > + "Failed to get vref\n"); > > Is it important to choose the external reference source _before_ > getting the voltage of the regulator? If not, I would swap these > calls, otherwise the comment is needed to explain why the sequence is > important in the way it's written. > > > + st->vref_mv = ret / 1000; > > + } > > + > > + mutex_init(&st->lock); > > + > > + return devm_iio_device_register(dev, indio_dev); > > +} > > + > > +static const struct of_device_id max14001_of_match[] = { > > + { .compatible = "adi,max14001" }, > > + { } > > +}; > > +MODULE_DEVICE_TABLE(of, max14001_of_match); > > + > > +static struct spi_driver max14001_driver = { > > + .driver = { > > + .name = "max14001", > > + .of_match_table = max14001_of_match, > > + }, > > + .probe = max14001_probe, > > +}; > > +module_spi_driver(max14001_driver); > > + > > +MODULE_AUTHOR("Kim Seer Paller"); > > +MODULE_DESCRIPTION("MAX14001 ADC driver"); > > +MODULE_LICENSE("GPL"); > > -- > > 2.34.1 > > > >
