On 26/03/17 11:08, jacopo wrote: > Hi Peter, > thanks for review > > On Sat, Mar 25, 2017 at 05:13:38PM +0100, Peter Meerwald-Stadler wrote: >> >> On Sat, 25 Mar 2017, Jonathan Cameron wrote: >> >> some more comments >> >>> 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 ;) >>> >>> 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 >> >> could use GENMASK() >> >>>> +#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 >> >> maybe avoid mixed-case #defines >> >>>> +/* 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) >> >> could use GENMASK() >> >>>> +#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] = { >> >> const >> >>>> + /* 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] = { >> >> const >> >>>> + { /* [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[] = { >> >> const >> >>>> + { >>>> + .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, >> >> why is this indexed? >> should be the only raw voltage channel >> >> >>>> + }, >>>> + { >>>> + .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... >> >> why is this indexed? >> should be the only processed voltage channel >> > > Jonathan already replied on this, but I would add that with no > indexing this would appear in userspace as: > > in_voltage_raw > in_voltage_scale > in_voltage_offset > in_offset_processed > > which is confusing at best. I hope that last one is in_voltage_processed! > > Hope is ok if I keep this indexed (in correct order as Jonathan said) > >> >>>> + }, >>>> + { >>>> + .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. >> >> maybe worth noting that data is MSB first or big-endian >> >>>> + * >>>> + * @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. >>> 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. >>>> + 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; >>>> + } >>>> + >> >> this falls through, no break? >> >> I'd move >> mutex_unlock(&dev->lock); >> return IIO_VAL_INT; >> here >> >> >>>> + case IIO_CHAN_INFO_OFFSET: >>>> + switch (chan->address) { >> >> rather pointless for only one case? >> >> >>>> + 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; >> >> default: return -EINVAL; >> >>>> + } >> >> break; or something >> > > I'll rewrite this with this and other comments in mind > > Thanks > j > >>>> + >>>> + 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? >>>> + 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... >>> >>>> + 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"); >>>> >>> >> >> -- >> >> Peter Meerwald-Stadler >> Mobile: +43 664 24 44 418 -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
