On 25/03/17 17:21, jacopo wrote: > Hi Jonathan, > thanks for review > > On Sat, Mar 25, 2017 at 03:45:05PM +0000, Jonathan Cameron wrote: >> On 24/03/17 15:28, Jacopo Mondi wrote: >>> Add iio driver for Maxim max9611 and max9612 current-sense amplifiers >>> with 12-bits ADC interface. >>> >>> Datasheet publicly available at: >>> https://datasheets.maximintegrated.com/en/ds/MAX9611-MAX9612.pdf >>> >>> Signed-off-by: Jacopo Mondi <jacopo+renesas@xxxxxxxxxx> >> A few more little things inline. Coming together nicely. >> >> The channel set here is just odd enough that it might aid review to have >> a quick listing of the resulting sysfs entries. One or two authors do >> this an it is always useful for a quick sanity check. >> >> Perhaps even a set of typical values. Put this below the --- as we don't >> need it in the git history, only to assist lazy reviewers like me ;) >> > > I included the output of iio_info in the cover letter, I can add some > more info here for sure! Just goes to show I don't always remember to check cover letters ;) > >> Thanks, >> >> Jonathan >>> --- >>> drivers/iio/adc/Kconfig | 10 + >>> drivers/iio/adc/Makefile | 1 + >>> drivers/iio/adc/max9611.c | 590 ++++++++++++++++++++++++++++++++++++++++++++++ >>> 3 files changed, 601 insertions(+) >>> create mode 100644 drivers/iio/adc/max9611.c >>> >>> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig >>> index dedae7a..82f2e7b8 100644 >>> --- a/drivers/iio/adc/Kconfig >>> +++ b/drivers/iio/adc/Kconfig >>> @@ -354,6 +354,16 @@ config MAX1363 >>> To compile this driver as a module, choose M here: the module will be >>> called max1363. >>> >>> +config MAX9611 >>> + tristate "Maxim max9611/max9612 ADC driver" >>> + depends on I2C >>> + help >>> + Say yes here to build support for Maxim max9611/max9612 current sense >>> + amplifier with 12-bits ADC interface. >>> + >>> + To compile this driver as a module, choose M here: the module will be >>> + called max9611. >>> + >>> config MCP320X >>> tristate "Microchip Technology MCP3x01/02/04/08" >>> depends on SPI >>> diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile >>> index d001262..149f979 100644 >>> --- a/drivers/iio/adc/Makefile >>> +++ b/drivers/iio/adc/Makefile >>> @@ -34,6 +34,7 @@ obj-$(CONFIG_LTC2485) += ltc2485.o >>> obj-$(CONFIG_MAX1027) += max1027.o >>> obj-$(CONFIG_MAX11100) += max11100.o >>> obj-$(CONFIG_MAX1363) += max1363.o >>> +obj-$(CONFIG_MAX9611) += max9611.o >>> obj-$(CONFIG_MCP320X) += mcp320x.o >>> obj-$(CONFIG_MCP3422) += mcp3422.o >>> obj-$(CONFIG_MEDIATEK_MT6577_AUXADC) += mt6577_auxadc.o >>> diff --git a/drivers/iio/adc/max9611.c b/drivers/iio/adc/max9611.c >>> new file mode 100644 >>> index 0000000..61566ec >>> --- /dev/null >>> +++ b/drivers/iio/adc/max9611.c >>> @@ -0,0 +1,590 @@ >>> +/* >>> + * iio/adc/max9611.c >>> + * >>> + * Maxim max9611/max9612 high side current sense amplifier with >>> + * 12-bit ADC interface. >>> + * >>> + * Copyright (C) 2017 Jacopo Mondi >>> + * >>> + * This program is free software; you can redistribute it and/or modify >>> + * it under the terms of the GNU General Public License version 2 as >>> + * published by the Free Software Foundation. >>> + */ >>> + >>> +/* >>> + * This driver supports input common-mode voltage, current-sense >>> + * amplifier with programmable gains and die temperature reading from >>> + * Maxim max9611/max9612. >>> + * >>> + * Op-amp, analog comparator, and watchdog functionalities are not >>> + * supported by this driver. >>> + */ >>> + >>> +#include <linux/delay.h> >>> +#include <linux/i2c.h> >>> +#include <linux/iio/iio.h> >>> +#include <linux/iio/sysfs.h> >>> +#include <linux/module.h> >>> + >>> +#define DRIVER_NAME "max9611" >>> + >>> +/* max9611 register addresses */ >>> +#define MAX9611_REG_CSA_DATA 0x00 >>> +#define MAX9611_REG_RS_DATA 0x02 >>> +#define MAX9611_REG_TEMP_DATA 0x08 >>> +#define MAX9611_REG_CTRL1 0x0a >>> +#define MAX9611_REG_CTRL2 0x0b >>> + >>> +/* max9611 REG1 mux configuration options */ >>> +#define MAX9611_MUX_MASK 0x07 >>> +#define MAX9611_MUX_SENSE_1x 0x00 >>> +#define MAX9611_MUX_SENSE_4x 0x01 >>> +#define MAX9611_MUX_SENSE_8x 0x02 >>> +#define MAX9611_INPUT_VOLT 0x03 >>> +#define MAX9611_MUX_TEMP 0x06 >>> + >>> +/* max9611 voltage (both csa and input) helper macros */ >>> +#define MAX9611_VOLTAGE_SHIFT 0x04 >>> +#define MAX9611_VOLTAGE_RAW(_r) ((_r) >> MAX9611_VOLTAGE_SHIFT) >>> + >>> +/* >>> + * max9611 current sense amplifier voltage output: >>> + * LSB and offset values depends on selected gain (1x, 4x, 8x) >>> + * >>> + * GAIN LSB (nV) OFFSET (LSB steps) >>> + * 1x 107500 1 >>> + * 4x 26880 1 >>> + * 8x 13440 3 >>> + * >>> + * The complete formula to calculate current sense voltage is: >>> + * (((adc_read >> 4) - offset) / ((1 / LSB) * 10^-3) >>> + */ >>> +#define CSA_VOLT_1x_LSB_nV 107500 >>> +#define CSA_VOLT_4x_LSB_nV 26880 >>> +#define CSA_VOLT_8x_LSB_nV 13440 >>> + >>> +#define CSA_VOLT_1x_OFFS_RAW 1 >>> +#define CSA_VOLT_4x_OFFS_RAW 1 >>> +#define CSA_VOLT_8x_OFFS_RAW 3 >>> + >>> +/* >>> + * max9611 common input mode (CIM): LSB is 14mV, with 14mV offset at 25 C >>> + * >>> + * The complete formula to calculate input common voltage is: >>> + * (((adc_read >> 4) * 1000) - offset) / (1 / 14 * 1000) >>> + */ >>> +#define CIM_VOLTAGE_LSB_mV 14 >>> +#define CIM_VOLTAGE_OFFSET_RAW 1 >>> + >>> +/* >>> + * max9611 temperature reading: LSB is 0.48 degrees Celsius >>> + * >>> + * The complete formula to calculate temperature is: >>> + * ((adc_read >> 7) * 1000) / (1 / 0.48 * 1000) >>> + */ >> I'd prefer these defines to be prefixed with MAX9611_ >> Easiest to just do the lot. Some of these are 'standard' enough >> the might well clash with something that turns up in an included header >> at somepoint in the future. >> >>> +#define TEMP_SHIFT 0x07 >>> +#define TEMP_MAX_RAW_POS 0x7f80 >>> +#define TEMP_MAX_RAW_NEG 0xff80 >>> +#define TEMP_MIN_RAW_NEG 0xd980 >>> +#define TEMP_MASK ((1 << TEMP_SHIFT) - 1) >>> +#define TEMP_RAW(_r) ((_r) >> TEMP_SHIFT) >>> +#define TEMP_LSB_mC 480 >>> +#define TEMP_SCALE_NUM 1000 >>> +#define TEMP_SCALE_DIV 2083 >>> + >>> +struct max9611_dev { >>> + struct device *dev; >>> + struct i2c_client *i2c_client; >>> + struct mutex lock; >>> + unsigned int shunt_resistor_uohm; >>> +}; >>> + >>> +enum max9611_conf_ids { >>> + CONF_SENSE_1x, >>> + CONF_SENSE_4x, >>> + CONF_SENSE_8x, >>> + CONF_IN_VOLT, >>> + CONF_TEMP, >>> +}; >>> + >>> +/** >>> + * max9611_mux_conf - associate ADC mux configuration with register address >>> + * where data shall be read from >>> + */ >>> +static unsigned int max9611_mux_conf[][2] = { >>> + /* CONF_SENSE_1x */ >>> + { MAX9611_MUX_SENSE_1x, MAX9611_REG_CSA_DATA }, >>> + /* CONF_SENSE_4x */ >>> + { MAX9611_MUX_SENSE_4x, MAX9611_REG_CSA_DATA }, >>> + /* CONF_SENSE_8x */ >>> + { MAX9611_MUX_SENSE_8x, MAX9611_REG_CSA_DATA }, >>> + /* CONF_IN_VOLT */ >>> + { MAX9611_INPUT_VOLT, MAX9611_REG_RS_DATA }, >>> + /* CONF_TEMP */ >>> + { MAX9611_MUX_TEMP, MAX9611_REG_TEMP_DATA }, >>> +}; >>> + >>> +enum max9611_csa_gain { >>> + CSA_GAIN_1x, >>> + CSA_GAIN_4x, >>> + CSA_GAIN_8x, >>> +}; >>> + >>> +enum max9611_csa_gain_params { >>> + CSA_GAIN_LSB_nV, >>> + CSA_GAIN_OFFS_RAW, >>> +}; >>> + >>> +/** >>> + * max9611_csa_gain_conf - associate gain multiplier with LSB and >>> + * offset values. >>> + * >>> + * Group together parameters associated with configurable gain >>> + * on current sense amplifier path to ADC interface. >>> + * Current sense read routine adjusts gain until it gets a meaningful >>> + * value; use this structure to retrieve the correct LSB and offset values. >>> + */ >>> +static unsigned int max9611_gain_conf[][2] = { >>> + { /* [0] CSA_GAIN_1x */ >>> + CSA_VOLT_1x_LSB_nV, >>> + CSA_VOLT_1x_OFFS_RAW, >>> + }, >>> + { /* [1] CSA_GAIN_4x */ >>> + CSA_VOLT_4x_LSB_nV, >>> + CSA_VOLT_4x_OFFS_RAW, >>> + }, >>> + { /* [2] CSA_GAIN_8x */ >>> + CSA_VOLT_8x_LSB_nV, >>> + CSA_VOLT_8x_OFFS_RAW, >>> + }, >>> +}; >>> + >>> +enum max9611_chan_addrs { >>> + MAX9611_CHAN_VOLTAGE_INPUT, >>> + MAX9611_CHAN_VOLTAGE_SENSE, >>> + MAX9611_CHAN_TEMPERATURE, >>> + MAX9611_CHAN_CURRENT_LOAD, >>> + MAX9611_CHAN_POWER_LOAD, >>> +}; >>> + >>> +static struct iio_chan_spec max9611_channels[] = { >>> + { >>> + .type = IIO_TEMP, >>> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | >>> + BIT(IIO_CHAN_INFO_SCALE), >>> + .address = MAX9611_CHAN_TEMPERATURE, >>> + }, >>> + { >>> + .type = IIO_VOLTAGE, >>> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | >>> + BIT(IIO_CHAN_INFO_SCALE) | >>> + BIT(IIO_CHAN_INFO_OFFSET), >>> + .address = MAX9611_CHAN_VOLTAGE_INPUT, >>> + .indexed = 1, >>> + .channel = 1, >>> + }, >>> + { >>> + .type = IIO_VOLTAGE, >>> + .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), >>> + .address = MAX9611_CHAN_VOLTAGE_SENSE, >>> + .indexed = 1, >>> + .channel = 0, >> Unusual to have the channels in here other than in channel order... >>> + }, >>> + { >>> + .type = IIO_CURRENT, >>> + .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), >>> + .address = MAX9611_CHAN_CURRENT_LOAD, >>> + }, >>> + { >>> + .type = IIO_POWER, >>> + .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), >>> + .address = MAX9611_CHAN_POWER_LOAD >>> + }, >>> +}; >>> + >>> +/** >>> + * max9611_read_single() - read a single vale from ADC interface >> value >>> + * >>> + * Data registers are 16 bit long, spread between two 8 bit registers >>> + * with consecutive addresses. >>> + * Configure ADC mux first, then read register at address "reg_addr". >>> + * The smbus_read_word routine asks for 16 bits and the ADC is kind enough >>> + * to return values from "reg_addr" and "reg_addr + 1" consecutively. >>> + * >>> + * @max9611: max9611 device >>> + * @selector: index for mux and register configuration >>> + * @raw_val: the value returned from ADC >>> + */ >>> +static int max9611_read_single(struct max9611_dev *max9611, >>> + enum max9611_conf_ids selector, >>> + u16 *raw_val) >>> +{ >>> + int ret; >>> + >>> + u8 mux_conf = max9611_mux_conf[selector][0] & MAX9611_MUX_MASK; >>> + u8 reg_addr = max9611_mux_conf[selector][1]; >>> + >>> + ret = i2c_smbus_write_byte_data(max9611->i2c_client, >>> + MAX9611_REG_CTRL1, mux_conf); >>> + if (ret) { >>> + dev_err(max9611->dev, "i2c write byte failed: 0x%2x - 0x%2x\n", >>> + MAX9611_REG_CTRL1, mux_conf); >>> + return ret; >>> + } >>> + >>> + /* >>> + * need a delay here to make register configuration >>> + * stabilize. 1 msec at least, from empirical testing. >>> + */ >>> + usleep_range(1000, 2000); >>> + >>> + ret = i2c_smbus_read_word_swapped(max9611->i2c_client, reg_addr); >>> + if (ret < 0) { >>> + dev_err(max9611->dev, "i2c read word from 0x%2x failed\n", >>> + reg_addr); >>> + return ret; >>> + } >>> + *raw_val = ret; >>> + >>> + return 0; >>> +} >>> + >>> +/** >>> + * max9611_read_csa_voltage() - read current sense amplifier output voltage >>> + * >>> + * Current sense amplifier output voltage is read through a configurable >>> + * 1x, 4x or 8x gain. >>> + * Start with plain 1x gain, and adjust gain control properly until a >>> + * meaningful value is read from ADC output. >>> + * >>> + * @max9611: max9611 device >>> + * @adc_raw: raw value read from ADC output >>> + * @csa_gain: gain configuration option selector >>> + */ >>> +static int max9611_read_csa_voltage(struct max9611_dev *max9611, >>> + u16 *adc_raw, >>> + enum max9611_csa_gain *csa_gain) >>> +{ >>> + enum max9611_conf_ids gain_selectors[] = { >>> + CONF_SENSE_1x, >>> + CONF_SENSE_4x, >>> + CONF_SENSE_8x >>> + }; >>> + unsigned int i; >>> + int ret; >>> + >>> + for (i = 0; i < ARRAY_SIZE(gain_selectors); ++i) { >>> + ret = max9611_read_single(max9611, gain_selectors[i], adc_raw); >>> + if (ret) >>> + return ret; >>> + >>> + if (*adc_raw > 0) { >>> + *csa_gain = gain_selectors[i]; >>> + return 0; >>> + } >>> + } >>> + >>> + return -EIO; >>> +} >>> + >>> +static int max9611_read_raw(struct iio_dev *indio_dev, >>> + struct iio_chan_spec const *chan, >>> + int *val, int *val2, long mask) >>> +{ >>> + struct max9611_dev *dev = iio_priv(indio_dev); >>> + enum max9611_csa_gain gain_selector; >>> + unsigned int *csa_gain; >>> + u16 adc_data; >>> + int ret; >>> + >>> + switch (mask) { >>> + case IIO_CHAN_INFO_RAW: >>> + mutex_lock(&dev->lock); >>> + >>> + switch (chan->address) { >>> + case MAX9611_CHAN_TEMPERATURE: >>> + ret = max9611_read_single(dev, CONF_TEMP, >>> + &adc_data); >>> + if (ret) >> I'm not personally keen on jumping out of deep indentations like this >> just save on repeating one line. I'd pull the unlock back here and return >> directly as I feel it'll improve readability. > > I'll change it, with this and Peter's suggestion on this function in > his review. > >> Actually come to think of it, why does the lock need to be held for >> the next line anyway? adc_data is on the stack so doesn't matter if we >> have concurrent readers, once the i2c transaction is finished. >> Just unlock before checking ret. > > I naively overvalued 'style' (ret assignment and check in two > consecutive lines) over practicality... I'll change this > >>> + goto unlock_fail; >>> + >>> + *val = TEMP_RAW(adc_data); >>> + >>> + mutex_unlock(&dev->lock); >>> + return IIO_VAL_INT; >>> + >>> + case MAX9611_CHAN_VOLTAGE_INPUT: >>> + ret = max9611_read_single(dev, CONF_IN_VOLT, >>> + &adc_data); >>> + if (ret) >>> + goto unlock_fail; >>> + >>> + *val = MAX9611_VOLTAGE_RAW(adc_data); >>> + >>> + mutex_unlock(&dev->lock); >>> + return IIO_VAL_INT; >>> + } >>> + >>> + case IIO_CHAN_INFO_OFFSET: >>> + switch (chan->address) { >>> + case MAX9611_CHAN_VOLTAGE_INPUT: >>> + *val = CIM_VOLTAGE_OFFSET_RAW; >>> + >>> + return IIO_VAL_INT; >>> + } >>> + >>> + case IIO_CHAN_INFO_SCALE: >>> + switch (chan->address) { >>> + case MAX9611_CHAN_TEMPERATURE: >>> + *val = TEMP_SCALE_NUM; >>> + *val2 = TEMP_SCALE_DIV; >>> + >>> + return IIO_VAL_FRACTIONAL; >>> + >>> + case MAX9611_CHAN_VOLTAGE_INPUT: >>> + *val = CIM_VOLTAGE_LSB_mV; >>> + return IIO_VAL_INT; >>> + } >>> + >>> + case IIO_CHAN_INFO_PROCESSED: >>> + mutex_lock(&dev->lock); >>> + >>> + switch (chan->address) { >>> + case MAX9611_CHAN_VOLTAGE_SENSE: >>> + /* >>> + * processed (mV): (raw - offset) * LSB (nV) / 10^6 >>> + * >>> + * Even if max9611 can output raw csa voltage readings, >>> + * use a produced value as scale depends on gain. >>> + */ >>> + ret = max9611_read_csa_voltage(dev, &adc_data, >>> + &gain_selector); >>> + if (ret) >>> + goto unlock_fail; >>> + >>> + csa_gain = max9611_gain_conf[gain_selector]; >>> + >>> + adc_data -= csa_gain[CSA_GAIN_OFFS_RAW]; >>> + *val = MAX9611_VOLTAGE_RAW(adc_data) * >>> + csa_gain[CSA_GAIN_LSB_nV]; >>> + *val2 = 1000000; >>> + >>> + mutex_unlock(&dev->lock); >>> + return IIO_VAL_FRACTIONAL; >>> + >>> + case MAX9611_CHAN_CURRENT_LOAD: >>> + /* processed (mA): Vcsa (nV) / Rshunt (uOhm) */ >>> + ret = max9611_read_csa_voltage(dev, &adc_data, >>> + &gain_selector); >>> + if (ret) >>> + goto unlock_fail; >>> + >>> + csa_gain = max9611_gain_conf[gain_selector]; >>> + >>> + adc_data -= csa_gain[CSA_GAIN_OFFS_RAW]; >>> + *val = MAX9611_VOLTAGE_RAW(adc_data) * >>> + csa_gain[CSA_GAIN_LSB_nV]; >>> + *val2 = dev->shunt_resistor_uohm; >>> + >>> + mutex_unlock(&dev->lock); >>> + return IIO_VAL_FRACTIONAL; >>> + >>> + case MAX9611_CHAN_POWER_LOAD: >>> + /* >>> + * processed (mW): Vin (mV) * Vcsa (uV) / >>> + * Rshunt (uOhm) >>> + */ >>> + ret = max9611_read_single(dev, CONF_IN_VOLT, >>> + &adc_data); >>> + if (ret) >>> + goto unlock_fail; >>> + >>> + adc_data -= CIM_VOLTAGE_OFFSET_RAW; >>> + *val = MAX9611_VOLTAGE_RAW(adc_data) * >>> + CIM_VOLTAGE_LSB_mV; >>> + >>> + ret = max9611_read_csa_voltage(dev, &adc_data, >>> + &gain_selector); >>> + if (ret) >>> + goto unlock_fail; >>> + >>> + csa_gain = max9611_gain_conf[gain_selector]; >>> + >>> + /* divide by 10^3 here to avoid 32bit overflow */ >>> + adc_data -= csa_gain[CSA_GAIN_OFFS_RAW]; >>> + *val *= MAX9611_VOLTAGE_RAW(adc_data) * >>> + csa_gain[CSA_GAIN_LSB_nV] / 1000; >>> + *val2 = dev->shunt_resistor_uohm; >>> + >>> + mutex_unlock(&dev->lock); >>> + return IIO_VAL_FRACTIONAL; >>> + } >>> + } >>> + >>> + ret = -EINVAL; >>> + >>> +unlock_fail: >>> + mutex_unlock(&dev->lock); >>> + return ret; >>> + >>> +} >>> + >>> +static ssize_t max9611_shunt_resistor_show(struct device *dev, >>> + struct device_attribute *attr, >>> + char *buf) >>> +{ >>> + struct max9611_dev *max9611 = iio_priv(dev_to_iio_dev(dev)); >>> + >>> + return sprintf(buf, "%d\n", max9611->shunt_resistor_uohm); >>> +} >>> + >>> +static IIO_DEVICE_ATTR(in_shunt_resistor_power, 0444, >>> + max9611_shunt_resistor_show, NULL, 0); >>> +static IIO_DEVICE_ATTR(in_shunt_resistor_current, 0444, >>> + max9611_shunt_resistor_show, NULL, 0); >>> + >>> +static struct attribute *max9611_attributes[] = { >>> + &iio_dev_attr_in_shunt_resistor_power.dev_attr.attr, >>> + &iio_dev_attr_in_shunt_resistor_current.dev_attr.attr, >>> + NULL, >>> +}; >>> + >>> +static const struct attribute_group max9611_attribute_group = { >>> + .attrs = max9611_attributes, >>> +}; >>> + >>> +static const struct iio_info indio_info = { >>> + .driver_module = THIS_MODULE, >>> + .read_raw = max9611_read_raw, >>> + .attrs = &max9611_attribute_group, >>> +}; >>> + >>> +static int max9611_init(struct max9611_dev *max9611) >>> +{ >>> + struct i2c_client *client = max9611->i2c_client; >>> + u16 regval; >>> + int ret; >>> + >>> + if (!i2c_check_functionality(client->adapter, >>> + I2C_FUNC_SMBUS_WRITE_BYTE | >>> + I2C_FUNC_SMBUS_READ_WORD_DATA)) { >>> + dev_err(max9611->dev, >>> + "No smbus support in I2c adapter: aborting probe.\n"); >> This isn't necessarily an accurate message. I2c adapter might support >> smbus_read_byte only rather than word reads for example. >> >> Maybe make it more explict as to what we need? > > Chopped away some details to make it fit in 80 columns.. I'll make it > more verbose... > >>> + return -EINVAL; >>> + } >>> + >>> + /* Configure MUX to read temperature */ >>> + ret = i2c_smbus_write_byte_data(max9611->i2c_client, >>> + MAX9611_REG_CTRL1, MAX9611_MUX_TEMP); >>> + if (ret) { >>> + dev_err(max9611->dev, "i2c write byte failed: 0x%2x - 0x%2x\n", >>> + MAX9611_REG_CTRL1, MAX9611_MUX_TEMP); >>> + return ret; >>> + } >>> + ret = i2c_smbus_write_byte_data(max9611->i2c_client, >>> + MAX9611_REG_CTRL2, 0); >>> + if (ret) { >>> + dev_err(max9611->dev, "i2c write byte failed: 0x%2x - 0x%2x\n", >>> + MAX9611_REG_CTRL2, 0); >>> + return ret; >>> + } >>> + usleep_range(1000, 2000); >>> + >>> + /* Make sure die temperature is in range to test communications. */ >>> + ret = i2c_smbus_read_word_swapped(max9611->i2c_client, >>> + MAX9611_REG_TEMP_DATA); >>> + if (ret < 0) { >>> + dev_err(max9611->dev, "i2c read word from 0x%2x failed\n", >>> + MAX9611_REG_TEMP_DATA); >>> + return ret; >>> + } >>> + regval = ret & ~TEMP_MASK; >>> + >>> + if ((regval > TEMP_MAX_RAW_POS && >>> + regval < TEMP_MIN_RAW_NEG) || >>> + regval > TEMP_MAX_RAW_NEG) { >>> + dev_err(max9611->dev, >>> + "Invalid value received from ADC 0x%4x: aborting\n", >>> + regval); >>> + return -EIO; >>> + } >>> + >>> + /* Mux shall be zeroed back before applying other configurations */ >>> + ret = i2c_smbus_write_byte_data(max9611->i2c_client, >>> + MAX9611_REG_CTRL1, 0); >>> + if (ret) { >>> + dev_err(max9611->dev, "i2c write byte failed: 0x%2x - 0x%2x\n", >>> + MAX9611_REG_CTRL1, 0); >>> + return ret; >>> + } >>> + usleep_range(1000, 2000); >>> + >>> + return 0; >>> +} >>> + >>> +static int max9611_probe(struct i2c_client *client, >>> + const struct i2c_device_id *id) >>> +{ >>> + const char * const shunt_res_prop = "shunt-resistor-uohm"; >>> + struct device_node *of_node = client->dev.of_node; >>> + struct max9611_dev *max9611; >>> + struct iio_dev *indio_dev; >>> + unsigned int of_shunt; >>> + int ret; >>> + >>> + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*max9611)); >>> + if (IS_ERR(indio_dev)) >>> + return PTR_ERR(indio_dev); >>> + >>> + i2c_set_clientdata(client, indio_dev); >>> + >>> + max9611 = iio_priv(indio_dev); >>> + max9611->dev = &client->dev; >>> + max9611->i2c_client = client; >>> + mutex_init(&max9611->lock); >>> + >>> + ret = of_property_read_u32(of_node, shunt_res_prop, &of_shunt); >>> + if (ret) { >>> + dev_err(&client->dev, >>> + "Missing %s property for %s node\n", >>> + shunt_res_prop, of_node->full_name); >>> + return ret; >>> + } >>> + max9611->shunt_resistor_uohm = of_shunt; >>> + >>> + ret = max9611_init(max9611); >>> + if (ret) >>> + return ret; >>> + >>> + indio_dev->dev.parent = &client->dev; >>> + indio_dev->dev.of_node = client->dev.of_node; >>> + indio_dev->name = client->dev.of_node->name; >> What's this going to give for the name? Name in IIO is supposed to >> be an indication of the part rather than anything more explicit. >> That's not easily obtained from device tree directly... >> > > I used the one coming from device tree as otherwise device entries > have the same name, and I wanted to have it to inclued the unit > address (eg. adc@7c and not just adc) > But from you comment I guess it's fine just adc, so I'll change this > back to v1). Should be the part number - so max9611 or similar.. You can query the device node details directly if you need to identify which is which. > > Thanks > j > >>> + indio_dev->modes = INDIO_DIRECT_MODE; >>> + indio_dev->info = &indio_info; >>> + indio_dev->channels = max9611_channels; >>> + indio_dev->num_channels = ARRAY_SIZE(max9611_channels); >>> + >>> + return devm_iio_device_register(&client->dev, indio_dev); >>> +} >>> + >>> +static const struct of_device_id max9611_of_table[] = { >>> + {.compatible = "maxim,max9611"}, >>> + {.compatible = "maxim,max9612"}, >>> + { }, >>> +}; >>> + >>> +MODULE_DEVICE_TABLE(of, max9611_of_table); >>> + >>> +static struct i2c_driver max9611_driver = { >>> + .driver = { >>> + .name = DRIVER_NAME, >>> + .owner = THIS_MODULE, >>> + .of_match_table = max9611_of_table, >>> + }, >>> + .probe = max9611_probe, >>> +}; >>> +module_i2c_driver(max9611_driver); >>> + >>> +MODULE_AUTHOR("Jacopo Mondi <jacopo+renesas@xxxxxxxxxx>"); >>> +MODULE_DESCRIPTION("Maxim max9611/12 current sense amplifier with 12bit ADC"); >>> +MODULE_LICENSE("GPL v2"); >>> >>
