Messages in this thread | | | Date | Wed, 26 Jul 2023 09:14:59 -0700 | From | Guenter Roeck <> | Subject | Re: [PATCH 1/2] hwmon: (isl28022) new driver for ISL28022 power monitor |
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On 7/26/23 08:22, Carsten Spieß wrote: > Driver for Renesas ISL28022 power monitor with I2C interface. > The device monitors voltage, current via shunt resistor > and calculated power. > > Signed-off-by: Carsten Spieß <mail@carsten-spiess.de> > --- > Documentation/hwmon/index.rst | 1 + > Documentation/hwmon/isl28022.rst | 56 +++++ > MAINTAINERS | 7 + > drivers/hwmon/Kconfig | 11 + > drivers/hwmon/Makefile | 1 + > drivers/hwmon/isl28022.c | 405 +++++++++++++++++++++++++++++++ > 6 files changed, 481 insertions(+) > create mode 100644 Documentation/hwmon/isl28022.rst > create mode 100644 drivers/hwmon/isl28022.c > > diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst > index d11924667f76..c9548fc5c40e 100644 > --- a/Documentation/hwmon/index.rst > +++ b/Documentation/hwmon/index.rst > @@ -90,6 +90,7 @@ Hardware Monitoring Kernel Drivers > ir35221 > ir38064 > ir36021 > + isl28022 > isl68137 > it87 > jc42 > diff --git a/Documentation/hwmon/isl28022.rst b/Documentation/hwmon/isl28022.rst > new file mode 100644 > index 000000000000..84c27ddcd33e > --- /dev/null > +++ b/Documentation/hwmon/isl28022.rst > @@ -0,0 +1,56 @@ > +.. SPDX-License-Identifier: GPL-2.0-or-later > + > +Kernel driver isl28022 > +====================== > + > +Supported chips: > + > + * Renesas ISL28022 > + > + Prefix: 'isl28022' > + > + Addresses scanned: none > + > + Datasheet: Publicly available at the Renesas website > + > + https://www.renesas.com/us/en/www/doc/datasheet/isl28022.pdf > + > +Author: > + Carsten Spieß <mail@carsten-spiess.de> > + > +Description > +----------- > + > +The ISL28022 is a power monitor with I2C interface. The device monitors > +voltage, current via shunt resistor and calculated power. > + > +Usage Notes > +----------- > + > +This driver does not auto-detect devices. You will have to instantiate the > +device explicitly. Please see Documentation/i2c/instantiating-devices.rst for > +details. > + > +The shunt value in micro-ohms, shunt gain and averaging can be set > +via device tree at compile-time.
At _compile-time_ ?
> +Please refer to the Documentation/devicetree/bindings/hwmon/isl,isl28022.yaml > +for bindings if the device tree is used. > + > +Sysfs entries > +------------- > + > +The following attributes are supported. All attributes are read-only. > + > +======================= ======================================================= > +in0_input shunt voltage (micro Volt)
No. You must not change the ABI like that.
> +in1_input bus voltage (milli Volt) > + > +curr1_input current (milli Ampere) > +power1_input power (micro Watt) > + > +note current and power attributes are supported only when > + shunt value is configured via device tree
No. Use a reasonable default if there are no devicetree properties. > + > + shunt voltage is in micro Volt, not milli Volt, > + to get useful values
I'd argue that shunt voltage is all but useless, but if you want to have it supported it _has_ to be in mV.
Why not support limit attributes ?
> +======================= ======================================================= > diff --git a/MAINTAINERS b/MAINTAINERS > index 7abb5710e1bb..c61aa688cd11 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -11072,6 +11072,13 @@ S: Maintained > F: Documentation/filesystems/isofs.rst > F: fs/isofs/ > > +ISL28022 HARDWARE MONITORING DRIVER > +M: Carsten Spieß <mail@carsten-spiess.de> > +L: linux-hwmon@vger.kernel.org > +S: Maintained > +F: Documentation/hwmon/isl28022.rst > +F: drivers/hwmon/isl28022.c > + > IT87 HARDWARE MONITORING DRIVER > M: Jean Delvare <jdelvare@suse.com> > L: linux-hwmon@vger.kernel.org > diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig > index 2913299c2c9e..3049c519e6ac 100644 > --- a/drivers/hwmon/Kconfig > +++ b/drivers/hwmon/Kconfig > @@ -800,6 +800,17 @@ config SENSORS_CORETEMP > sensor inside your CPU. Most of the family 6 CPUs > are supported. Check Documentation/hwmon/coretemp.rst for details. > > +config SENSORS_ISL28022 > + tristate "Renesas ISL28022" > + depends on I2C > + select REGMAP_I2C > + help > + If you say yes here you get support for ISL28022 power monitor. > + Check Documentation/hwmon/isl28022.rst for details. > + > + This driver can also be built as a module. If so, the module > + will be called isl28022. > + > config SENSORS_IT87 > tristate "ITE IT87xx and compatibles" > depends on !PPC > diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile > index ff6bfd109c72..4046fed7f48d 100644 > --- a/drivers/hwmon/Makefile > +++ b/drivers/hwmon/Makefile > @@ -98,6 +98,7 @@ obj-$(CONFIG_SENSORS_INA2XX) += ina2xx.o > obj-$(CONFIG_SENSORS_INA238) += ina238.o > obj-$(CONFIG_SENSORS_INA3221) += ina3221.o > obj-$(CONFIG_SENSORS_INTEL_M10_BMC_HWMON) += intel-m10-bmc-hwmon.o > +obj-$(CONFIG_SENSORS_ISL28022) += isl28022.o > obj-$(CONFIG_SENSORS_IT87) += it87.o > obj-$(CONFIG_SENSORS_JC42) += jc42.o > obj-$(CONFIG_SENSORS_K8TEMP) += k8temp.o > diff --git a/drivers/hwmon/isl28022.c b/drivers/hwmon/isl28022.c > new file mode 100644 > index 000000000000..67cf47c31600 > --- /dev/null > +++ b/drivers/hwmon/isl28022.c > @@ -0,0 +1,405 @@ > +// SPDX-License-Identifier: GPL-2.0-or-later > +/* > + * isl28022.c - driver for Renesas ISL28022 power monitor chip > + * monitoring > + * Copyright (c) 2023 Carsten Spieß <mail@carsten-spiess.de> > + */ > + > +#include <linux/module.h> > +#include <linux/init.h> > +#include <linux/slab.h> > +#include <linux/i2c.h> > +#include <linux/hwmon.h> > +#include <linux/hwmon-sysfs.h> > +#include <linux/err.h> > +#include <linux/of_device.h> > +#include <linux/of.h> > +#include <linux/regmap.h> > +#include <linux/util_macros.h> > +#include <linux/regulator/consumer.h> > + > +/* ISL28022 registers */ > +#define ISL28022_REG_CONFIG 0x00 > +#define ISL28022_REG_SHUNT 0x01 > +#define ISL28022_REG_BUS 0x02 > +#define ISL28022_REG_POWER 0x03 > +#define ISL28022_REG_CURRENT 0x04 > +#define ISL28022_REG_CALIB 0x05 > +#define ISL28022_REG_SHUNT_THR 0x06 > +#define ISL28022_REG_BUS_THR 0x07 > +#define ISL28022_REG_INT 0x08 > +#define ISL28022_REG_AUX 0x09 > +#define ISL28022_REG_MAX ISL28022_REG_AUX > + > +/* ISL28022 config flags */ > +/* mode flags */ > +#define ISL28022_MODE_SHIFT 0 > +#define ISL28022_MODE_MASK 0x0007 > + > +#define ISL28022_MODE_PWR_DOWN 0x0 > +#define ISL28022_MODE_TRG_S 0x1 > +#define ISL28022_MODE_TRG_B 0x2 > +#define ISL28022_MODE_TRG_SB 0x3 > +#define ISL28022_MODE_ADC_OFF 0x4 > +#define ISL28022_MODE_CONT_S 0x5 > +#define ISL28022_MODE_CONT_B 0x6 > +#define ISL28022_MODE_CONT_SB 0x7 > + > +/* shunt ADC settings */ > +#define ISL28022_SADC_SHIFT 3 > +#define ISL28022_SADC_MASK 0x0078 > + > +#define ISL28022_BADC_SHIFT 7 > +#define ISL28022_BADC_MASK 0x0780 > + > +#define ISL28022_ADC_12 0x0 /* 12 bit ADC */ > +#define ISL28022_ADC_13 0x1 /* 13 bit ADC */ > +#define ISL28022_ADC_14 0x2 /* 14 bit ADC */ > +#define ISL28022_ADC_15 0x3 /* 15 bit ADC */ > +#define ISL28022_ADC_15_1 0x8 /* 15 bit ADC, 1 sample */ > +#define ISL28022_ADC_15_2 0x9 /* 15 bit ADC, 2 samples */ > +#define ISL28022_ADC_15_4 0xA /* 15 bit ADC, 4 samples */ > +#define ISL28022_ADC_15_8 0xB /* 15 bit ADC, 8 samples */ > +#define ISL28022_ADC_15_16 0xC /* 15 bit ADC, 16 samples */ > +#define ISL28022_ADC_15_32 0xD /* 15 bit ADC, 32 samples */ > +#define ISL28022_ADC_15_64 0xE /* 15 bit ADC, 64 samples */ > +#define ISL28022_ADC_15_128 0xF /* 15 bit ADC, 128 samples */ > + > +/* shunt voltage range */ > +#define ISL28022_PG_SHIFT 11 > +#define ISL28022_PG_MASK 0x1800 > + > +#define ISL28022_PG_40 0x0 /* +/-40 mV */ > +#define ISL28022_PG_80 0x1 /* +/-80 mV */ > +#define ISL28022_PG_160 0x2 /* +/-160 mV */ > +#define ISL28022_PG_320 0x3 /* +/-3200 mV */ > + > +/* bus voltage range */ > +#define ISL28022_BRNG_SHIFT 13 > +#define ISL28022_BRNG_MASK 0x6000 > + > +#define ISL28022_BRNG_16 0x0 /* 16 V */ > +#define ISL28022_BRNG_32 0x1 /* 32 V */ > +#define ISL28022_BRNG_60 0x3 /* 60 V */ > + > +/* reset */ > +#define ISL28022_RESET 0x8000 > + > +struct isl28022_data { > + struct i2c_client *client; > + struct regmap *regmap; > + u32 shunt; > + u32 gain; > + u32 average; > + u16 config; > + u16 calib; > +}; > + > +static int isl28022_read(struct device *dev, enum hwmon_sensor_types type, > + u32 attr, int channel, long *val) > +{ > + struct isl28022_data *data = dev_get_drvdata(dev); > + unsigned int regval; > + int err; > + > + switch (type) { > + case hwmon_in: > + switch (attr) { > + case hwmon_in_input: > + err = regmap_read(data->regmap, > + ISL28022_REG_SHUNT + channel, ®val);
That never reads REG_BUS.
> + if (err < 0) > + return err; > + *val = (channel == 0) ? > + (long)((s16)((u16)regval)) * 10 : > + (long)(((u16)regval) & 0xFFFC);
I don't think the sign extensions are correct based on the datasheet. This will have to use sign_extend.
> + break; > + default: > + return -EINVAL; > + } > + break; > + case hwmon_curr: > + switch (attr) { > + case hwmon_curr_input: > + err = regmap_read(data->regmap, > + ISL28022_REG_CURRENT, ®val); > + if (err < 0) > + return err; > + if (!data->shunt) > + return -EINVAL;
Getting an error message each time the "sensors" command is executed ? Unacceptable.
> + *val = ((long)regval * 10000L * (long)data->gain) / > + (long)(8 * data->shunt); > + break; > + default: > + return -EINVAL; > + } > + break; > + case hwmon_power: > + switch (attr) { > + case hwmon_power_input: > + err = regmap_read(data->regmap, > + ISL28022_REG_POWER, ®val); > + if (err < 0) > + return err; > + if (!data->shunt) > + return -EINVAL;
Unacceptable.
> + *val = ((long)regval * 409600000L * (long)data->gain) / > + (long)(8 * data->shunt);
I don't think this was checked for overflows.
> + break; > + default: > + return -EINVAL; > + } > + break; > + default: > + return -EINVAL; > + } > + > + return 0; > +} > + > +static umode_t isl28022_is_visible(const void *data, enum hwmon_sensor_types type, > + u32 attr, int channel) > +{ > + switch (type) { > + case hwmon_in: > + switch (attr) { > + case hwmon_in_input: > + return 0444; > + } > + break; > + case hwmon_curr: > + switch (attr) { > + case hwmon_curr_input: > + return 0444; > + } > + break; > + case hwmon_power: > + switch (attr) { > + case hwmon_power_input: > + return 0444; > + } > + break; > + default: > + break; > + } > + return 0; > +} > + > +static const struct hwmon_channel_info *isl28022_info[] = { > + HWMON_CHANNEL_INFO(in, > + HWMON_I_INPUT, /* channel 0: shunt voltage (µV) */ > + HWMON_I_INPUT), /* channel 1: bus voltage (mV) */ > + NULL > +}; > + > +static const struct hwmon_channel_info *isl28022_info_shunt[] = { > + HWMON_CHANNEL_INFO(in, > + HWMON_I_INPUT, /* channel 0: shunt voltage (µV) */ > + HWMON_I_INPUT), /* channel 1: bus voltage (mV) */ > + HWMON_CHANNEL_INFO(curr, > + HWMON_C_INPUT), /* channel 1: current (mA) */ > + HWMON_CHANNEL_INFO(power, > + HWMON_P_INPUT), /* channel 1: power (µW) */ > + NULL > +}; > + > +static const struct hwmon_ops isl28022_hwmon_ops = { > + .is_visible = isl28022_is_visible, > + .read = isl28022_read, > +}; > + > +static const struct hwmon_chip_info isl28022_chip_info = { > + .ops = &isl28022_hwmon_ops, > + .info = isl28022_info, > +}; > + > +static const struct hwmon_chip_info isl28022_chip_info_shunt = { > + .ops = &isl28022_hwmon_ops, > + .info = isl28022_info_shunt, > +}; > + > +static bool isl28022_is_writeable_reg(struct device *dev, unsigned int reg) > +{ > + switch (reg) { > + case ISL28022_REG_CONFIG: > + case ISL28022_REG_CALIB: > + case ISL28022_REG_SHUNT_THR: > + case ISL28022_REG_BUS_THR: > + case ISL28022_REG_INT: > + case ISL28022_REG_AUX: > + return true; > + } > + > + return false; > +} > + > +static bool isl28022_is_volatile_reg(struct device *dev, unsigned int reg) > +{ > + switch (reg) { > + case ISL28022_REG_CONFIG: > + case ISL28022_REG_SHUNT: > + case ISL28022_REG_BUS: > + case ISL28022_REG_POWER: > + case ISL28022_REG_CURRENT: > + case ISL28022_REG_INT: > + case ISL28022_REG_AUX: > + return true; > + } > + return true; > +} > + > +static const struct regmap_config isl28022_regmap_config = { > + .reg_bits = 8, > + .val_bits = 16, > + .max_register = ISL28022_REG_MAX, > + .writeable_reg = isl28022_is_writeable_reg, > + .volatile_reg = isl28022_is_volatile_reg, > + .val_format_endian = REGMAP_ENDIAN_BIG, > + .cache_type = REGCACHE_RBTREE, > + .use_single_read = true, > + .use_single_write = true, > +}; > + > +static const struct i2c_device_id isl28022_ids[] = { > + { "isl28022", 0}, > + { /* LIST END */ } > +}; > +MODULE_DEVICE_TABLE(i2c, isl28022_ids); > + > +static int isl28022_config(struct device *dev) > +{ > + struct isl28022_data *data = dev_get_drvdata(dev); > + > + if (!dev || !data) > + return -EINVAL;
How would this ever happen ?
> + ; > + data->config = (ISL28022_MODE_CONT_SB << ISL28022_MODE_SHIFT) | > + (ISL28022_BRNG_60 << ISL28022_BRNG_SHIFT); > + > + switch (data->gain) { > + case 1: > + data->config |= (ISL28022_PG_40 << ISL28022_PG_SHIFT); > + break; > + case 2: > + data->config |= (ISL28022_PG_80 << ISL28022_PG_SHIFT); > + break; > + case 4: > + data->config |= (ISL28022_PG_160 << ISL28022_PG_SHIFT); > + break; > + default: > + data->config |= (ISL28022_PG_320 << ISL28022_PG_SHIFT); > + data->gain = 8; > + break; > + } > + > + data->calib = data->shunt ? 0x8000 / data->gain : 0; > + > + switch (data->average) { > + case 128: > + data->config |= (ISL28022_ADC_15_128 << ISL28022_SADC_SHIFT) | > + (ISL28022_ADC_15_128 << ISL28022_BADC_SHIFT); > + break; > + case 64: > + data->config |= (ISL28022_ADC_15_64 << ISL28022_SADC_SHIFT) | > + (ISL28022_ADC_15_64 << ISL28022_BADC_SHIFT); > + break; > + case 32: > + data->config |= (ISL28022_ADC_15_32 << ISL28022_SADC_SHIFT) | > + (ISL28022_ADC_15_32 << ISL28022_BADC_SHIFT); > + break; > + case 16: > + data->config |= (ISL28022_ADC_15_16 << ISL28022_SADC_SHIFT) | > + (ISL28022_ADC_15_16 << ISL28022_BADC_SHIFT); > + break; > + case 8: > + data->config |= (ISL28022_ADC_15_8 << ISL28022_SADC_SHIFT) | > + (ISL28022_ADC_15_8 << ISL28022_BADC_SHIFT); > + break; > + case 4: > + data->config |= (ISL28022_ADC_15_4 << ISL28022_SADC_SHIFT) | > + (ISL28022_ADC_15_4 << ISL28022_BADC_SHIFT); > + break; > + case 2: > + data->config |= (ISL28022_ADC_15_2 << ISL28022_SADC_SHIFT) | > + (ISL28022_ADC_15_2 << ISL28022_BADC_SHIFT); > + break; > + case 1: > + data->config |= (ISL28022_ADC_15_1 << ISL28022_SADC_SHIFT) | > + (ISL28022_ADC_15_1 << ISL28022_BADC_SHIFT); > + break; > + default: > + data->config |= (ISL28022_ADC_15 << ISL28022_SADC_SHIFT) | > + (ISL28022_ADC_15 << ISL28022_BADC_SHIFT); > + data->average = 0; > + break; > + } > + > + regmap_write(data->regmap, ISL28022_REG_CONFIG, data->config); > + regmap_write(data->regmap, ISL28022_REG_CALIB, data->calib);
Error checking needed.
> + > + return 0; > +} > + > +static int isl28022_probe(struct i2c_client *client) > +{ > + struct device *dev = &client->dev; > + struct device *hwmon_dev; > + struct isl28022_data *data; > + int status; > + > + if (!i2c_check_functionality(client->adapter, > + I2C_FUNC_SMBUS_BYTE_DATA | > + I2C_FUNC_SMBUS_WORD_DATA)) > + return -EIO;
This is not an IO error. Return -ENODEV as most other drivers do.
> + > + data = devm_kzalloc(dev, sizeof(struct isl28022_data), GFP_KERNEL); > + if (!data) > + return -ENOMEM; > + > + data->client = client; > + > + of_property_read_u32(dev->of_node, "shunt-resistor-micro-ohms", &data->shunt); > + of_property_read_u32(dev->of_node, "shunt-gain", &data->gain); > + of_property_read_u32(dev->of_node, "average", &data->average);
Check for errors and provide defaults if properties are not set. Also please use device_property_read_u32() to enable use from non-devicetree systems.
> + > + data->regmap = devm_regmap_init_i2c(client, &isl28022_regmap_config); > + if (IS_ERR(data->regmap)) > + return PTR_ERR(data->regmap); > + > + hwmon_dev = devm_hwmon_device_register_with_info(dev, "isl28022_hwmon", > + data, data->shunt ? > + &isl28022_chip_info_shunt : > + &isl28022_chip_info, NULL); > + if (IS_ERR(hwmon_dev)) > + return PTR_ERR(hwmon_dev); > + > + status = isl28022_config(hwmon_dev); > + if (status) > + return status;
That has to happen before the call to devm_hwmon_device_register_with_info() to avoid race conditions.
> + > + dev_info(dev, "%s: sensor '%s'\n", dev_name(hwmon_dev), client->name); > + > + return 0; > +} > + > +static const struct of_device_id __maybe_unused isl28022_of_match[] = { > + { .compatible = "renesas,isl28022"}, > + { /* LIST END */ } > +}; > +MODULE_DEVICE_TABLE(of, isl28022_of_match); > + > +static struct i2c_driver isl28022_driver = { > + .class = I2C_CLASS_HWMON, > + .driver = { > + .name = "isl28022", > + .of_match_table = of_match_ptr(isl28022_of_match),
Drop of_match_ptr()
> + }, > + .probe_new = isl28022_probe, > + .id_table = isl28022_ids, > +}; > + > +module_i2c_driver(isl28022_driver); > + > +MODULE_AUTHOR("Carsten Spiess <mail@carsten-spiess.de>"); > +MODULE_DESCRIPTION("ISL28022 driver"); > +MODULE_LICENSE("GPL");
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