[PATCH] hwmon (pmbus): Add client driver for IR35221

Guenter Roeck linux at roeck-us.net
Fri Apr 21 23:49:23 AEST 2017


On 04/20/2017 09:25 PM, Samuel Mendoza-Jonas wrote:
> IR35221 is a Digital DC-DC Multiphase Converter
>
> Signed-off-by: Samuel Mendoza-Jonas <sam at mendozajonas.com>
> ---
> - Tested on a ppc64 system which includes several of these devices.
> - This patch re-implements the linear reg2data/data2reg functions from
>   pmbus-core like some other drivers in order to scale some results. Is
>   this something that would be better off being made generic for pmbus
>   drivers to call?

That might make sense. The only other driver is zl6100, or am I missing
something ?

Trying to understand the code, the data format seems to be linear11 with
an added exponent on top of it. Is that correct ? If so, I wonder if we should
make that configurable, ie store the additional exponent in R and handle it
in the pmbus core. Would that help ?

If so, and if you have time, feel free to provide patches the modify the
pmbus core code accordingly.

> - The resolution of iout0 is apparently configurable between two values,
>   however the documentation I have access to does not specify how this is
>   actually configured - currently it is left at the default resolution in
>   the driver.
>

Nothing we can do about that, but it might make sense to add a note somewhere
in the driver.

>  Documentation/hwmon/ir35221   |  87 ++++++++++++
>  drivers/hwmon/pmbus/Kconfig   |  11 ++
>  drivers/hwmon/pmbus/Makefile  |   1 +
>  drivers/hwmon/pmbus/ir35221.c | 322 ++++++++++++++++++++++++++++++++++++++++++
>  4 files changed, 421 insertions(+)
>  create mode 100644 Documentation/hwmon/ir35221
>  create mode 100644 drivers/hwmon/pmbus/ir35221.c
>
> diff --git a/Documentation/hwmon/ir35221 b/Documentation/hwmon/ir35221
> new file mode 100644
> index 000000000000..f7e112752c04
> --- /dev/null
> +++ b/Documentation/hwmon/ir35221
> @@ -0,0 +1,87 @@
> +Kernel driver ir35221
> +=====================
> +
> +Supported chips:
> +  * Infinion IR35221
> +    Prefix: 'ir35221'
> +    Addresses scanned: -
> +    Datasheet: Datasheet is not publicly available.

The chip doesn't even publicly exist, which is really annoying :-(.

> +
> +Author: Samuel Mendoza-Jonas <sam at mendozajonas.com>
> +
> +
> +Description
> +-----------
> +
> +IR35221 is a Digital DC-DC Multiphase Converter
> +
> +
> +Usage Notes
> +-----------
> +
> +This driver does not probe for PMBus devices. You will have to instantiate
> +devices explicitly.
> +
> +Example: the following commands will load the driver for an IR35221
> +at address 0x70 on I2C bus #4:
> +
> +# modprobe ir35221
> +# echo ir35221 0x70 > /sys/bus/i2c/devices/i2c-4/new_device
> +
> +
> +Sysfs attributes
> +----------------
> +
> +curr1_label		"iin"
> +curr1_input		Measured input current
> +curr1_max		Maximum current
> +curr1_max_alarm		Current high alarm
> +
> +curr[2-3]_label		"iout[1-2]"
> +curr[2-3]_input		Measured output current
> +curr[2-3]_crit		Critical maximum current
> +curr[2-3]_crit_alarm	Current critical high alarm
> +curr[2-3]_highest	Highest output current
> +curr[2-3]_lowest	Lowest output current
> +curr[2-3]_max		Maximum current
> +curr[2-3]_max_alarm	Current high alarm
> +
> +in1_label		"vin"
> +in1_input		Measured input voltage
> +in1_crit		Critical maximum input voltage
> +in1_crit_alarm		Input voltage critical high alarm
> +in1_highest		Highest input voltage
> +in1_lowest		Lowest input voltage
> +in1_min			Minimum input voltage
> +in1_min_alarm		Input voltage low alarm
> +
> +in[2-3]_label		"vout[1-2]"
> +in[2-3]_input		Measured output voltage
> +in[2-3]_lcrit		Critical minimum output voltage
> +in[2-3]_lcrit_alarm	Output voltage critical low alarm
> +in[2-3]_crit		Critical maximum output voltage
> +in[2-3]_crit_alarm	Output voltage critical high alarm
> +in[2-3]_highest		Highest output voltage
> +in[2-3]_lowest		Lowest output voltage
> +in[2-3]_max		Maximum output voltage
> +in[2-3]_max_alarm	Output voltage high alarm
> +in[2-3]_min		Minimum output voltage
> +in[2-3]_min_alarm	Output voltage low alarm
> +
> +power1_label		"pin"
> +power1_input		Measured input power
> +power1_alarm		Input power high alarm
> +power1_max		Input power limit
> +
> +power[2-3]_label	"pout[1-2]"
> +power[2-3]_input	Measured output power
> +power[2-3]_max		Output power limit
> +power[2-3]_max_alarm	Output power high alarm
> +
> +temp[1-2]_input		Measured temperature
> +temp[1-2]_crit		Critical high temperature
> +temp[1-2]_crit_alarm	Chip temperature critical high alarm
> +temp[1-2]_highest	Highest temperature
> +temp[1-2]_lowest	Lowest temperature
> +temp[1-2]_max		Maximum temperature
> +temp[1-2]_max_alarm	Chip temperature high alarm
> diff --git a/drivers/hwmon/pmbus/Kconfig b/drivers/hwmon/pmbus/Kconfig
> index cad1229b7e17..88c7d6b116f8 100644
> --- a/drivers/hwmon/pmbus/Kconfig
> +++ b/drivers/hwmon/pmbus/Kconfig
> @@ -159,4 +159,15 @@ config SENSORS_ZL6100
>  	  This driver can also be built as a module. If so, the module will
>  	  be called zl6100.
>
> +config SENSORS_IR35221
> +	tristate "Infineon IR35221"
> +	default n
> +	help
> +	  If you say yes here you get hardware monitoring support for the
> +	  Infineon IR35221 controller.
> +
> +	  This driver can also be built as a module. If so, the module will
> +	  be called ir35521.
> +
> +
>  endif # PMBUS
> diff --git a/drivers/hwmon/pmbus/Makefile b/drivers/hwmon/pmbus/Makefile
> index 562132054aaf..75bb7ca619d9 100644
> --- a/drivers/hwmon/pmbus/Makefile
> +++ b/drivers/hwmon/pmbus/Makefile
> @@ -5,6 +5,7 @@
>  obj-$(CONFIG_PMBUS)		+= pmbus_core.o
>  obj-$(CONFIG_SENSORS_PMBUS)	+= pmbus.o
>  obj-$(CONFIG_SENSORS_ADM1275)	+= adm1275.o
> +obj-$(CONFIG_SENSORS_IR35221)	+= ir35221.o
>  obj-$(CONFIG_SENSORS_LM25066)	+= lm25066.o
>  obj-$(CONFIG_SENSORS_LTC2978)	+= ltc2978.o
>  obj-$(CONFIG_SENSORS_LTC3815)	+= ltc3815.o
> diff --git a/drivers/hwmon/pmbus/ir35221.c b/drivers/hwmon/pmbus/ir35221.c
> new file mode 100644
> index 000000000000..e73b1aeb0085
> --- /dev/null
> +++ b/drivers/hwmon/pmbus/ir35221.c
> @@ -0,0 +1,322 @@
> +/*
> + * Hardware monitoring driver for IR35221
> + *
> + * Copyright (C) IBM Corporation 2017.
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License
> + * as published by the Free Software Foundation; either version
> + * 2 of the License, or (at your option) any later version.
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/err.h>
> +#include <linux/init.h>
> +#include <linux/i2c.h>

Alphabetic order please.

> +#include "pmbus.h"
> +
> +#define IR35221_IC_DEVICE_ID		0xad
> +#define IR35221_IC_DEVICE_REV		0xae
> +#define IR35221_USER_DATA_00		0xb0
> +#define IR35221_USER_DATA_01		0xb1
> +#define IR35221_MFR_READ_VAUX		0xc4
> +#define IR35221_MFR_VIN_PEAK		0xc5
> +#define IR35221_MFR_VOUT_PEAK		0xc6
> +#define IR35221_MFR_IOUT_PEAK		0xc7
> +#define IR35221_MFR_TEMP_PEAK		0xc8
> +#define IR35221_MFR_VIN_VALLEY		0xc9
> +#define IR35221_MFR_VOUT_VALLEY		0xca
> +#define IR35221_MFR_IOUT_VALLEY		0xcb
> +#define IR35221_MFR_TEMP_VALLEY		0xcc
> +#define IR35221_VOUT_RESET		0xce
> +#define IR35221_RESET_TRANSITION_RATE	0xcf
> +#define IR35221_MFR_REG_ACCESS		0xd0
> +#define IR35221_MFR_I2C_ADDRESS		0xd6

I don't think those are all used. Please drop the unused definitions.

> +
> +static long ir35221_reg2data(int data, enum pmbus_sensor_classes class)
> +{
> +	s16 exponent;
> +	s32 mantissa;
> +	long val;
> +
> +	/* We only modify LINEAR11 formats */
> +	exponent = ((s16)data) >> 11;
> +	mantissa = ((s16)((data & 0x7ff) << 5)) >> 5;
> +
> +	val = mantissa * 1000L;
> +
> +	/* scale result to micro-units for power sensors */
> +	if (class == PSC_POWER)
> +		val = val * 1000L;
> +
> +	if (exponent >= 0)
> +		val <<= exponent;
> +	else
> +		val >>= -exponent;
> +
> +	return val;
> +}
> +
> +#define MAX_MANTISSA	(1023 * 1000)
> +#define MIN_MANTISSA	(511 * 1000)
> +
> +static u16 ir35221_data2reg(long val, enum pmbus_sensor_classes class)
> +{
> +	s16 exponent = 0, mantissa;
> +	bool negative = false;
> +
> +	if (val == 0)
> +		return 0;
> +
> +	if (val < 0) {
> +		negative = true;
> +		val = -val;
> +	}
> +
> +	/* Power is in uW. Convert to mW before converting. */
> +	if (class == PSC_POWER)
> +		val = DIV_ROUND_CLOSEST(val, 1000L);
> +
> +	/* Reduce large mantissa until it fits into 10 bit */
> +	while (val >= MAX_MANTISSA && exponent < 15) {
> +		exponent++;
> +		val >>= 1;
> +	}
> +	/* Increase small mantissa to improve precision */
> +	while (val < MIN_MANTISSA && exponent > -15) {
> +		exponent--;
> +		val <<= 1;
> +	}
> +
> +	/* Convert mantissa from milli-units to units */
> +	mantissa = DIV_ROUND_CLOSEST(val, 1000);
> +
> +	/* Ensure that resulting number is within range */
> +	if (mantissa > 0x3ff)
> +		mantissa = 0x3ff;
> +
> +	/* restore sign */
> +	if (negative)
> +		mantissa = -mantissa;
> +
> +	/* Convert to 5 bit exponent, 11 bit mantissa */
> +	return (mantissa & 0x7ff) | ((exponent << 11) & 0xf800);
> +}
> +
> +static u16 ir35221_scale_result(s16 data, int shift,
> +				enum pmbus_sensor_classes class)
> +{
> +	long val;
> +
> +	val = ir35221_reg2data(data, class);
> +
> +	if (shift < 0)
> +		val >>= -shift;
> +	else
> +		val <<= shift;
> +
> +	return ir35221_data2reg(val, class);
> +}
> +
> +static int ir35221_read_word_data(struct i2c_client *client, int page, int reg)
> +{
> +	int ret;
> +
> +	switch (reg) {
> +	case PMBUS_IOUT_OC_FAULT_LIMIT:
> +	case PMBUS_IOUT_OC_WARN_LIMIT:
> +		ret = pmbus_read_word_data(client, page, reg);
> +		ret = ir35221_scale_result(ret, 1, PSC_CURRENT_OUT);
> +		break;
> +	case PMBUS_VIN_OV_FAULT_LIMIT:
> +	case PMBUS_VIN_OV_WARN_LIMIT:
> +	case PMBUS_VIN_UV_WARN_LIMIT:
> +		ret = pmbus_read_word_data(client, page, reg);
> +		ret = ir35221_scale_result(ret, -4, PSC_VOLTAGE_IN);
> +		break;
> +	case PMBUS_IIN_OC_WARN_LIMIT:
> +		ret = pmbus_read_word_data(client, page, reg);
> +		ret = ir35221_scale_result(ret, -1, PSC_CURRENT_IN);
> +	case PMBUS_READ_VIN:
> +		ret = pmbus_read_word_data(client, page, PMBUS_READ_VIN);
> +		ret = ir35221_scale_result(ret, -5, PSC_VOLTAGE_IN);
> +		break;
> +	case PMBUS_READ_IIN:
> +		ret = pmbus_read_word_data(client, page, PMBUS_READ_IIN);
> +		if (page == 0)
> +			ret = ir35221_scale_result(ret, -4, PSC_CURRENT_IN);
> +		else
> +			ret = ir35221_scale_result(ret, -5, PSC_CURRENT_IN);

Wow, per-page exponent. Someone was inventive.
If we move scaling to the core, this would still be simpler as the additional
scale could be handled here.

> +		break;
> +	case PMBUS_READ_POUT:
> +		ret = pmbus_read_word_data(client, page, PMBUS_READ_POUT);
> +		ret = ir35221_scale_result(ret, -1, PSC_POWER);
> +		break;
> +	case PMBUS_READ_PIN:
> +		ret = pmbus_read_word_data(client, page, PMBUS_READ_PIN);
> +		ret = ir35221_scale_result(ret, -1, PSC_POWER);
> +		break;
> +	case PMBUS_READ_IOUT:
> +		ret = pmbus_read_word_data(client, page, PMBUS_READ_IOUT);
> +		if (page == 0)
> +			ret = ir35221_scale_result(ret, -1, PSC_CURRENT_OUT);
> +		else
> +			ret = ir35221_scale_result(ret, -2, PSC_CURRENT_OUT);
> +		break;
> +	case PMBUS_VIRT_READ_VIN_MAX:
> +		ret = pmbus_read_word_data(client, page, IR35221_MFR_VIN_PEAK);
> +		ret = ir35221_scale_result(ret, -5, PSC_VOLTAGE_IN);
> +		break;
> +	case PMBUS_VIRT_READ_VOUT_MAX:
> +		ret = pmbus_read_word_data(client, page, IR35221_MFR_VOUT_PEAK);
> +		break;
> +	case PMBUS_VIRT_READ_IOUT_MAX:
> +		ret = pmbus_read_word_data(client, page, IR35221_MFR_IOUT_PEAK);
> +		if (page == 0)
> +			ret = ir35221_scale_result(ret, -1, PSC_CURRENT_IN);
> +		else
> +			ret = ir35221_scale_result(ret, -2, PSC_CURRENT_IN);
> +		break;
> +	case PMBUS_VIRT_READ_TEMP_MAX:
> +		ret = pmbus_read_word_data(client, page, IR35221_MFR_TEMP_PEAK);
> +		break;
> +	case PMBUS_VIRT_READ_VIN_MIN:
> +		ret = pmbus_read_word_data(client, page,
> +					   IR35221_MFR_VIN_VALLEY);
> +		ret = ir35221_scale_result(ret, -5, PSC_VOLTAGE_IN);
> +		break;
> +	case PMBUS_VIRT_READ_VOUT_MIN:
> +		ret = pmbus_read_word_data(client, page,
> +					   IR35221_MFR_VOUT_VALLEY);
> +		break;
> +	case PMBUS_VIRT_READ_IOUT_MIN:
> +		ret = pmbus_read_word_data(client, page,
> +					   IR35221_MFR_IOUT_VALLEY);
> +		if (page == 0)
> +			ret = ir35221_scale_result(ret, -1, PSC_CURRENT_IN);
> +		else
> +			ret = ir35221_scale_result(ret, -2, PSC_CURRENT_IN);
> +		break;
> +	case PMBUS_VIRT_READ_TEMP_MIN:
> +		ret = pmbus_read_word_data(client, page,
> +					   IR35221_MFR_TEMP_VALLEY);
> +		break;
> +	default:
> +		ret = -ENODATA;
> +		break;
> +	}
> +
> +	return ret;
> +}
> +
> +static int ir35221_write_word_data(struct i2c_client *client, int page, int reg,
> +				   u16 word)
> +{
> +	int ret;
> +	u16 val;
> +
> +	switch (reg) {
> +	case PMBUS_IOUT_OC_FAULT_LIMIT:
> +	case PMBUS_IOUT_OC_WARN_LIMIT:
> +		val = ir35221_scale_result(word, -1, PSC_CURRENT_OUT);
> +		ret = pmbus_write_word_data(client, page, reg, val);
> +		break;
> +	case PMBUS_VIN_OV_FAULT_LIMIT:
> +	case PMBUS_VIN_OV_WARN_LIMIT:
> +	case PMBUS_VIN_UV_WARN_LIMIT:
> +		val = ir35221_scale_result(word, 4, PSC_VOLTAGE_IN);
> +		ret = pmbus_write_word_data(client, page, reg, val);
> +		break;
> +	case PMBUS_IIN_OC_WARN_LIMIT:
> +		val = ir35221_scale_result(word, 1, PSC_CURRENT_IN);
> +		ret = pmbus_write_word_data(client, page, reg, val);
> +	default:
> +		ret = -ENODATA;
> +		break;
> +	}
> +
> +	return ret;
> +}
> +
> +static int ir35221_probe(struct i2c_client *client,
> +			 const struct i2c_device_id *id)
> +{
> +	struct pmbus_driver_info *info;
> +	u8 buf[I2C_SMBUS_BLOCK_MAX];
> +	int ret;
> +
> +	if (!i2c_check_functionality(client->adapter,
> +				     I2C_FUNC_SMBUS_READ_BYTE_DATA
> +				| I2C_FUNC_SMBUS_READ_WORD_DATA
> +				| I2C_FUNC_SMBUS_READ_BLOCK_DATA))
> +		return -ENODEV;
> +
> +	ret = i2c_smbus_read_block_data(client, PMBUS_MFR_ID, buf);
> +	if (ret < 0) {
> +		dev_err(&client->dev, "Failed to read PMBUS_MFR_ID\n");
> +		return ret;
> +	}
> +	if (ret != 2 || strncmp(buf, "RI", strlen("RI"))) {
> +		dev_err(&client->dev, "MFR_ID unrecognised\n");
> +		return -ENODEV;
> +	}
> +
> +	ret = i2c_smbus_read_block_data(client, PMBUS_MFR_MODEL, buf);
> +	if (ret < 0) {
> +		dev_err(&client->dev, "Failed to read PMBUS_MFR_MODEL\n");
> +		return ret;
> +	}
> +	if (ret != 2 || !(buf[0] == 0x6c && buf[1] == 0x00)) {
> +		dev_err(&client->dev, "MFR_MODEL unrecognised\n");
> +		return -ENODEV;
> +	}
> +
> +	info = devm_kzalloc(&client->dev, sizeof(struct pmbus_driver_info),
> +			    GFP_KERNEL);
> +	if (!info)
> +		return -ENOMEM;
> +
> +	info->write_word_data = ir35221_write_word_data;
> +	info->read_word_data = ir35221_read_word_data;
> +
> +	info->pages = 2;
> +	info->format[PSC_VOLTAGE_IN] = linear;
> +	info->format[PSC_VOLTAGE_OUT] = linear;
> +	info->format[PSC_CURRENT_IN] = linear;
> +	info->format[PSC_CURRENT_OUT] = linear;
> +	info->format[PSC_POWER] = linear;
> +	info->format[PSC_TEMPERATURE] = linear;
> +
> +	info->func[0] = PMBUS_HAVE_VIN
> +		| PMBUS_HAVE_VOUT | PMBUS_HAVE_IIN
> +		| PMBUS_HAVE_IOUT | PMBUS_HAVE_PIN
> +		| PMBUS_HAVE_POUT | PMBUS_HAVE_TEMP
> +		| PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_STATUS_IOUT
> +		| PMBUS_HAVE_STATUS_INPUT | PMBUS_HAVE_STATUS_TEMP;
> +	info->func[1] = info->func[0];
> +
> +	return pmbus_do_probe(client, id, info);
> +}
> +
> +static const struct i2c_device_id ir35221_id[] = {
> +	{"ir35221", 0},
> +	{}
> +};
> +
> +MODULE_DEVICE_TABLE(i2c, ir35221_id);
> +
> +static struct i2c_driver ir35221_driver = {
> +	.driver = {
> +		.name	= "ir35221",
> +	},
> +	.probe		= ir35221_probe,
> +	.remove		= pmbus_do_remove,
> +	.id_table	= ir35221_id,
> +};
> +
> +module_i2c_driver(ir35221_driver);
> +
> +MODULE_AUTHOR("Samuel Mendoza-Jonas <sam at mendozajonas.com");
> +MODULE_DESCRIPTION("PMBus driver for IR35221");
> +MODULE_LICENSE("GPL");
>



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