Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751459AbbKNS7i (ORCPT ); Sat, 14 Nov 2015 13:59:38 -0500 Received: from saturn.retrosnub.co.uk ([178.18.118.26]:41467 "EHLO saturn.retrosnub.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750762AbbKNS7f (ORCPT ); Sat, 14 Nov 2015 13:59:35 -0500 Subject: Re: [RFC v2 1/2] iio: ina2xx: add direct IO support for TI INA2xx Power Monitors To: Marc Titinger , knaack.h@gmx.de, lars@metafoo.de, pmeerw@pmeerw.net References: <1447333052-12791-1-git-send-email-mtitinger@baylibre.com> From: Jonathan Cameron X-Enigmail-Draft-Status: N1110 Cc: linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org, mturquette@baylibre.com, bcousson@baylibre.com, ptitiano@baylibre.com Message-ID: <56478493.3030703@kernel.org> Date: Sat, 14 Nov 2015 18:59:31 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 MIME-Version: 1.0 In-Reply-To: <1447333052-12791-1-git-send-email-mtitinger@baylibre.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 17448 Lines: 596 On 12/11/15 12:57, Marc Titinger wrote: > Basic support or direct IO raw read, with averaging attribute. > Values are RAW, INT_PLUS_MICRO (Volt/Ampere/Watt). > > Output of iio_info: > > iio:device0: ina226 > 4 channels found: > power3: (input) > 1 channel-specific attributes found: > attr 0: raw value: 1.150000 > voltage0: (input) > 1 channel-specific attributes found: > attr 0: raw value: 0.000003 > voltage1: (input) > 1 channel-specific attributes found: > attr 0: raw value: 4.277500 > current2: (input) > 1 channel-specific attributes found: > attr 0: raw value: 0.268000 > 2 device-specific attributes found: > attr 0: in_calibscale value: 10000 > attr 1: in_mean_raw value: 4 > attr 2: in_sampling_frequency value: 455 > > Tested with ina226, on BeagleBoneBlack. > > Datasheet: http://www.ti.com/lit/gpn/ina226 > > Signed-off-by: Marc Titinger Hi Marc To express a personal preference, please don't have series of patches as replies to the original thread. It gets really hard to follow after a couple of revisions! May seem a random question, but what do you want to gain from an IIO driver over what the hwmon provides? Various bits inline.. Mostly looks pretty good though. Jonathan > --- > > v2 of series https://lkml.org/lkml/2015/11/10/370 : > > - squash patches adding SAMPL_FREQ and debugfs interface > - add regmap is_volatile and is_writeable callbacks > - fix Kconfig deps and alphabetical sorting > - simplification: use devm_iio_device_register > > --- > > drivers/iio/adc/Kconfig | 9 + > drivers/iio/adc/Makefile | 1 + > drivers/iio/adc/ina2xx-iio.c | 472 +++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 482 insertions(+) > create mode 100644 drivers/iio/adc/ina2xx-iio.c > > diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig > index eb0cd89..087e5bd 100644 > --- a/drivers/iio/adc/Kconfig > +++ b/drivers/iio/adc/Kconfig > @@ -170,6 +170,15 @@ config EXYNOS_ADC > of SoCs for drivers such as the touchscreen and hwmon to use to share > this resource. > > +config INA2XX_IIO > + tristate "Texas Instruments INA2xx Power Monitors IIO driver" > + depends on I2C > + select REGMAP_I2C > + help > + Say yes here to build support for TI INA2xx familly Power Monitors. > + > + Note that this is not the existing hwmon interface for this device. > + > config LP8788_ADC > tristate "LP8788 ADC driver" > depends on MFD_LP8788 > diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile > index a096210..74e4341 100644 > --- a/drivers/iio/adc/Makefile > +++ b/drivers/iio/adc/Makefile > @@ -19,6 +19,7 @@ obj-$(CONFIG_BERLIN2_ADC) += berlin2-adc.o > obj-$(CONFIG_DA9150_GPADC) += da9150-gpadc.o > obj-$(CONFIG_CC10001_ADC) += cc10001_adc.o > obj-$(CONFIG_EXYNOS_ADC) += exynos_adc.o > +obj-$(CONFIG_INA2XX_IIO) += ina2xx-iio.o > obj-$(CONFIG_LP8788_ADC) += lp8788_adc.o > obj-$(CONFIG_MAX1027) += max1027.o > obj-$(CONFIG_MAX1363) += max1363.o > diff --git a/drivers/iio/adc/ina2xx-iio.c b/drivers/iio/adc/ina2xx-iio.c > new file mode 100644 > index 0000000..28b7919 > --- /dev/null > +++ b/drivers/iio/adc/ina2xx-iio.c > @@ -0,0 +1,472 @@ > +/* > + * INA2XX Current and Power Monitors > + * > + * Copyright 2015 Baylibre SAS. > + * > + * 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. > + * > + * Based on linux/drivers/iio/adc/ad7291.c > + * Copyright 2010-2011 Analog Devices Inc. > + * > + * Based on linux/drivers/hwmon/ina2xx.c > + * Copyright 2012 Lothar Felten > + * > + * Licensed under the GPL-2 or later. > + * > + * IIO driver for INA219-220-226-230-231 > + * > + * Configurable 7-bit I2C slave address from 0x40 to 0x4F > + */ > +#include > +#include > +#include > +#include > +#include > + > +#include > + > +/* > + * INA2XX registers definition > + */ > +/* common register definitions */ > +#define INA2XX_CONFIG 0x00 > +#define INA2XX_SHUNT_VOLTAGE 0x01 /* readonly */ > +#define INA2XX_BUS_VOLTAGE 0x02 /* readonly */ > +#define INA2XX_POWER 0x03 /* readonly */ > +#define INA2XX_CURRENT 0x04 /* readonly */ > +#define INA2XX_CALIBRATION 0x05 > + > +/* register count */ > +#define INA219_REGISTERS 6 > +#define INA226_REGISTERS 8 > +#define INA2XX_MAX_REGISTERS 8 > + > +/* settings - depend on use case */ > +#define INA219_CONFIG_DEFAULT 0x399F /* PGA=8 */ > +#define INA226_CONFIG_DEFAULT 0x4327 > +#define INA226_DEFAULT_AVG 4 > +#define INA226_DEFAULT_FREQ 454 > + > +#define INA2XX_RSHUNT_DEFAULT 10000 > + > +/* bit mask for reading the averaging setting in the configuration register */ > +#define INA226_AVG_RD_MASK 0x0E00 genmask is always good for these. > +#define INA226_READ_AVG(reg) (((reg) & INA226_AVG_RD_MASK) >> 9) > +#define INA226_SHIFT_AVG(val) ((val) << 9) > + > +#define INA226_SFREQ_RD_MASK 0x01f8 > + > + > +static bool ina2xx_is_writeable_reg(struct device *dev, unsigned int reg) > +{ > + return (reg == INA2XX_CONFIG) > + || (reg == INA2XX_CALIBRATION); On one line I think this is still way less than 80 chars.. > +} > + > +static bool ina2xx_is_volatile_reg(struct device *dev, unsigned int reg) > +{ > + return (reg != INA2XX_CONFIG); > +} > + > +static struct regmap_config ina2xx_regmap_config = { > + .reg_bits = 8, > + .val_bits = 16, > + > + .writeable_reg = ina2xx_is_writeable_reg, > + .volatile_reg = ina2xx_is_volatile_reg, > +}; > + > +enum ina2xx_ids { ina219, ina226 }; > + > +struct ina2xx_config { > + u16 config_default; > + int calibration_factor; > + int registers; > + int shunt_div; > + int bus_voltage_shift; > + int bus_voltage_lsb; /* uV */ > + int power_lsb; /* uW */ > +}; > + > +struct ina2xx_chip_info { > + struct iio_dev *indio_dev; Having a pointer back to the indio_dev is usually a sign of something 'unusual' going on... Will be interesting to see what it is for ;) Ah, that was easy, you don't use it that I can see. > + const struct ina2xx_config *config; > + struct mutex state_lock; > + long rshunt; > + int avg; > + int freq; > + int period_us; > + struct regmap *regmap; > +}; > + > +static const struct ina2xx_config ina2xx_config[] = { > + [ina219] = { > + .config_default = INA219_CONFIG_DEFAULT, > + .calibration_factor = 40960000, > + .registers = INA219_REGISTERS, > + .shunt_div = 100, > + .bus_voltage_shift = 3, > + .bus_voltage_lsb = 4000, > + .power_lsb = 20000, > + }, > + [ina226] = { > + .config_default = INA226_CONFIG_DEFAULT, > + .calibration_factor = 5120000, > + .registers = INA226_REGISTERS, > + .shunt_div = 400, > + .bus_voltage_shift = 0, > + .bus_voltage_lsb = 1250, > + .power_lsb = 25000, > + }, > +}; > + > +static int ina2xx_get_value(struct ina2xx_chip_info *chip, u8 reg, > + unsigned int regval, int *val, int *uval) > +{ > + *val = 0; > + > + switch (reg) { > + case INA2XX_SHUNT_VOLTAGE: > + /* signed register */ > + *uval = DIV_ROUND_CLOSEST((s16) regval, > + chip->config->shunt_div); > + *val = *uval/1000000; > + *uval = *uval - *val*1000000; > + return IIO_VAL_INT_PLUS_MICRO; I'm somewhat unconvinced that this wrapper is adding anything over just doing this where you care about the result. Also, this is a straight forward linear conversion. Do it in userspace by providing the relevant 'scale' element. > + > + case INA2XX_BUS_VOLTAGE: > + *uval = (regval >> chip->config->bus_voltage_shift) > + * chip->config->bus_voltage_lsb; > + *val = *uval/1000000; > + *uval = *uval - *val*1000000; > + return IIO_VAL_INT_PLUS_MICRO; > + > + case INA2XX_POWER: > + *uval = regval * chip->config->power_lsb; > + *val = *uval/1000000; > + *uval = *uval - *val*1000000; > + return IIO_VAL_INT_PLUS_MICRO; > + > + case INA2XX_CURRENT: > + /* signed register, LSB=1mA (selected), in mA */ > + *uval = (s16) regval * 1000; > + return IIO_VAL_INT_PLUS_MICRO; > + > + case INA2XX_CALIBRATION: > + *val = DIV_ROUND_CLOSEST(chip->config->calibration_factor, > + regval); > + return IIO_VAL_INT; > + > + default: > + /* programmer goofed */ > + WARN_ON_ONCE(1); > + } > + return -EINVAL; > +} > + > +static int ina2xx_read_raw(struct iio_dev *indio_dev, > + struct iio_chan_spec const *chan, > + int *val, int *val2, long mask) > +{ > + int ret; > + struct ina2xx_chip_info *chip = iio_priv(indio_dev); > + unsigned int regval; > + > + switch (mask) { > + case IIO_CHAN_INFO_RAW: > + ret = regmap_read(chip->regmap, chan->address, ®val); > + if (ret < 0) > + return ret; > + > + return ina2xx_get_value(chip, chan->address, regval, val, val2); > + > + case IIO_CHAN_INFO_AVERAGE_RAW: > + *val = chip->avg; > + return IIO_VAL_INT; > + > + case IIO_CHAN_INFO_CALIBSCALE: > + ret = regmap_read(chip->regmap, INA2XX_CALIBRATION, ®val); > + if (ret < 0) > + return ret; > + > + return ina2xx_get_value(chip, INA2XX_CALIBRATION, regval, > + val, val2); > + > + case IIO_CHAN_INFO_SAMP_FREQ: > + *val = chip->freq; > + return IIO_VAL_INT; > + > + default: > + return -EINVAL; > + } > + > + return 0; > +} > + > +static int ina2xx_calibrate(struct ina2xx_chip_info *chip) > +{ > + u16 val = DIV_ROUND_CLOSEST(chip->config->calibration_factor, > + chip->rshunt); > + > + return regmap_write(chip->regmap, INA2XX_CALIBRATION, val); > +} > + > + > +/* > + * Available averaging rates for ina226. The indices correspond with > + * the bit values expected by the chip (according to the ina226 datasheet, > + * table 3 AVG bit settings, found at > + * http://www.ti.com/lit/ds/symlink/ina226.pdf. > + */ > +static const int ina226_avg_tab[] = { 1, 4, 16, 64, 128, 256, 512, 1024 }; > + > +static unsigned int ina226_set_average(struct ina2xx_chip_info *chip, > + unsigned int val, > + unsigned int *config) > +{ > + int bits; > + > + if (val > 1024 || val < 1) > + return -EINVAL; > + > + bits = find_closest(val, ina226_avg_tab, > + ARRAY_SIZE(ina226_avg_tab)); > + > + chip->avg = ina226_avg_tab[bits]; > + > + *config &= ~INA226_AVG_RD_MASK; > + *config |= INA226_SHIFT_AVG(bits) & INA226_AVG_RD_MASK; > + > + return 0; > +} > + > +/* > + * Conversion times in uS > + */ > +static const int ina226_conv_time_tab[] = { 140, 204, 332, 588, 1100, > + 2116, 4156, 8244}; > + > +static unsigned int ina226_set_frequency(struct ina2xx_chip_info *chip, > + unsigned int val, > + unsigned int *config) > +{ > + int bits; > + > + if (val > 3550 || val < 50) > + return -EINVAL; > + > + /* integration time in uS, for both voltage channels */ > + val = DIV_ROUND_CLOSEST(1000000, 2 * val); > + > + bits = find_closest(val, ina226_conv_time_tab, > + ARRAY_SIZE(ina226_conv_time_tab)); > + > + chip->period_us = 2 * ina226_conv_time_tab[bits]; > + > + chip->freq = DIV_ROUND_CLOSEST(1000000, chip->period_us); > + > + *config &= ~INA226_SFREQ_RD_MASK; > + *config |= (bits << 3) | (bits << 6); > + > + return 0; > +} > + > + > +static int ina2xx_write_raw(struct iio_dev *indio_dev, > + struct iio_chan_spec const *chan, > + int val, int val2, long mask) > +{ > + struct ina2xx_chip_info *chip = iio_priv(indio_dev); > + int ret = 0; > + unsigned int config, tmp; > + > + mutex_lock(&chip->state_lock); > + > + ret = regmap_read(chip->regmap, INA2XX_CONFIG, &config); > + if (ret < 0) > + goto _err; > + > + tmp = config; > + > + switch (mask) { > + case IIO_CHAN_INFO_AVERAGE_RAW: > + > + ret = ina226_set_average(chip, val, &tmp); This isn't what the ABI uses the info_average_raw attribute for - it's for outputing the average of a channel rather than setting a mean filter width (which is what you have here). Probably need some new ABI for this as our current filter description ABI is rather limited! > + break; > + > + case IIO_CHAN_INFO_SAMP_FREQ: > + > + ret = ina226_set_frequency(chip, val, &tmp); > + break; > + > + default: > + ret = -EINVAL; > + } > + > + if (!ret && (tmp != config)) > + ret = regmap_write(chip->regmap, INA2XX_CONFIG, config); > +_err: > + mutex_unlock(&chip->state_lock); > + > + return ret; > +} > + > +#define INA2XX_CHAN(_type, _index, _address) { \ > + .type = _type, \ > + .address = _address, \ > + .indexed = 1, \ > + .channel = (_index), \ > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ > + .info_mask_shared_by_dir = BIT(IIO_CHAN_INFO_AVERAGE_RAW) | \ > + BIT(IIO_CHAN_INFO_SAMP_FREQ) | \ > + BIT(IIO_CHAN_INFO_CALIBSCALE), \ > + .scan_index = (_index), \ > + .scan_type = { \ > + .sign = 'u', \ > + .realbits = 16, \ > + .storagebits = 16, \ > + .shift = 0, \ > + .endianness = IIO_BE, \ > + } \ > +} > + > +static const struct iio_chan_spec ina2xx_channels[] = { > + INA2XX_CHAN(IIO_VOLTAGE, 0, INA2XX_SHUNT_VOLTAGE), > + INA2XX_CHAN(IIO_VOLTAGE, 1, INA2XX_BUS_VOLTAGE), > + INA2XX_CHAN(IIO_CURRENT, 2, INA2XX_CURRENT), > + INA2XX_CHAN(IIO_POWER, 3, INA2XX_POWER), > + IIO_CHAN_SOFT_TIMESTAMP(4), > +}; > + > +static int ina2xx_debug_reg(struct iio_dev *indio_dev, > + unsigned reg, unsigned writeval, unsigned *readval) > +{ > + struct ina2xx_chip_info *chip = iio_priv(indio_dev); > + > + if (!readval) > + return regmap_write(chip->regmap, reg, writeval); > + > + return regmap_read(chip->regmap, reg, readval); > +} > + > +static const struct iio_info ina2xx_info = { > + .debugfs_reg_access = &ina2xx_debug_reg, > + .read_raw = &ina2xx_read_raw, > + .write_raw = &ina2xx_write_raw, > + .driver_module = THIS_MODULE, > +}; > + > +/* Single line comment, use single line comment syntax. > +* Initialize the configuration and calibration registers. > +*/ > +static int ina2xx_init(struct ina2xx_chip_info *chip, unsigned int config) > +{ > + int ret = regmap_write(chip->regmap, INA2XX_CONFIG, config); > + > + if (ret < 0) > + return ret; > + /* > + * Set current LSB to 1mA, shunt is in uOhms > + * (equation 13 in datasheet). > + */ > + return ina2xx_calibrate(chip); > +} > + > +static int ina2xx_probe(struct i2c_client *client, > + const struct i2c_device_id *id) > +{ > + struct ina2xx_chip_info *chip; > + struct iio_dev *indio_dev; > + int ret; > + unsigned int val; > + > + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*chip)); > + if (!indio_dev) > + return -ENOMEM; > + > + chip = iio_priv(indio_dev); > + chip->indio_dev = indio_dev; > + > + /* set the device type */ > + chip->config = &ina2xx_config[id->driver_data]; > + > + if (of_property_read_u32(client->dev.of_node, > + "shunt-resistor", &val) < 0) { > + struct ina2xx_platform_data *pdata = > + dev_get_platdata(&client->dev); > + > + if (pdata) > + val = pdata->shunt_uohms; > + else > + val = INA2XX_RSHUNT_DEFAULT; > + } > + > + if (val <= 0 || val > chip->config->calibration_factor) > + return -ENODEV; > + > + chip->rshunt = val; > + > + ina2xx_regmap_config.max_register = chip->config->registers; > + > + mutex_init(&chip->state_lock); > + > + /* this is only used for device removal purposes */ > + i2c_set_clientdata(client, indio_dev); > + > + indio_dev->name = id->name; > + indio_dev->channels = ina2xx_channels; > + indio_dev->num_channels = ARRAY_SIZE(ina2xx_channels); > + > + indio_dev->dev.parent = &client->dev; > + indio_dev->info = &ina2xx_info; > + indio_dev->modes = INDIO_DIRECT_MODE; > + > + chip->regmap = devm_regmap_init_i2c(client, &ina2xx_regmap_config); > + if (IS_ERR(chip->regmap)) { > + dev_err(&client->dev, "failed to allocate register map\n"); > + return PTR_ERR(chip->regmap); > + } > + > + /* Patch the current config register with default. */ > + val = chip->config->config_default; > + if (id->driver_data == ina226) { > + ina226_set_average(chip, INA226_DEFAULT_AVG, &val); > + ina226_set_frequency(chip, INA226_DEFAULT_FREQ, &val); > + } > + > + ret = ina2xx_init(chip, val); > + if (ret < 0) { > + dev_err(&client->dev, "error configuring the device: %d\n", > + ret); > + return -ENODEV; > + } > + > + return devm_iio_device_register(&client->dev, indio_dev); > +} > + > +static const struct i2c_device_id ina2xx_id[] = { > + {"ina219", ina219}, > + {"ina220", ina219}, > + {"ina226", ina226}, > + {"ina230", ina226}, > + {"ina231", ina226}, > + {} > +}; > + > +MODULE_DEVICE_TABLE(i2c, ina2xx_id); > + > +static struct i2c_driver ina2xx_driver = { > + .driver = { > + .name = KBUILD_MODNAME, > + }, > + .probe = ina2xx_probe, > + .id_table = ina2xx_id, > +}; > + > +module_i2c_driver(ina2xx_driver); > + > +MODULE_AUTHOR("Marc Titinger "); > +MODULE_DESCRIPTION("Texas Instruments INA2XX ADC driver"); > +MODULE_LICENSE("GPL v2"); > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/