Re: [RFC 2/2] hwmon: powernv: Hwmon driver for OCC inband power and temperature sensors

[Guenter Roeck]

On Thu, Mar 09, 2017 at 05:19:15PM +0530, Shilpasri G Bhat wrote:
> Add support to read power and temperature sensors from OCC inband
> sensors which are copied to main memory by OCC.
>

Is this supposed to be an alternative to the submission from 
Eddie James ? If so, is there a reason to consider such an
alternative ?

Thanks,
Guenter

> Signed-off-by: Shilpasri G Bhat <shilpa.bhat@xxxxxxxxxxxxxxxxxx>
> CC: Rob Herring <robh+dt@xxxxxxxxxx>
> CC: Mark Rutland <mark.rutland@xxxxxxx>
> CC: Jean Delvare <jdelvare@xxxxxxxx>
> CC: Guenter Roeck <linux@xxxxxxxxxxxx>
> CC: Jonathan Corbet <corbet@xxxxxxx>
> CC: devicetree@xxxxxxxxxxxxxxx
> CC: linux-hwmon@xxxxxxxxxxxxxxx
> CC: linux-doc@xxxxxxxxxxxxxxx
> ---
>  .../devicetree/bindings/hwmon/ibmpowernv-occ.txt   |   4 +
>  Documentation/hwmon/ibmpowernv-occ                 |  24 ++
>  drivers/hwmon/Kconfig                              |  11 +
>  drivers/hwmon/Makefile                             |   1 +
>  drivers/hwmon/ibmpowernv-occ.c                     | 302 +++++++++++++++++++++
>  5 files changed, 342 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/hwmon/ibmpowernv-occ.txt
>  create mode 100644 Documentation/hwmon/ibmpowernv-occ
>  create mode 100644 drivers/hwmon/ibmpowernv-occ.c
> 
> diff --git a/Documentation/devicetree/bindings/hwmon/ibmpowernv-occ.txt b/Documentation/devicetree/bindings/hwmon/ibmpowernv-occ.txt
> new file mode 100644
> index 0000000..d03f744
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/hwmon/ibmpowernv-occ.txt
> @@ -0,0 +1,4 @@
> +IBM POWERNV OCC inband platform sensors
> +
> +Required device-tree property:
> +- compatible: "ibm,p9-occ-inband-sensor"
> diff --git a/Documentation/hwmon/ibmpowernv-occ b/Documentation/hwmon/ibmpowernv-occ
> new file mode 100644
> index 0000000..151028b
> --- /dev/null
> +++ b/Documentation/hwmon/ibmpowernv-occ
> @@ -0,0 +1,24 @@
> +Kernel driver ibmpowernv-occ
> +=============================
> +
> +Supported systems:
> + * P9 server based on POWERNV platform
> +
> +Description
> +------------
> +
> +This driver exports the power and temperature sensors from OCC inband
> +sensors on P9 POWERNV platforms.
> +
> +Sysfs attributes
> +----------------
> +
> +powerX_input		Latest power reading
> +powerX_input_highest	Minimum power
> +powerX_input_lowest	Maximum power
> +powerX_label		Sensor name
> +
> +tempX_input		Latest temperature reading
> +tempX_max		Minimum temperature
> +tempX_min		Maximum temperature
> +tempX_label		Sensor name
> diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
> index 0649d53f3..3b1dbb9 100644
> --- a/drivers/hwmon/Kconfig
> +++ b/drivers/hwmon/Kconfig
> @@ -598,6 +598,17 @@ config SENSORS_IBMPOWERNV
>  	  This driver can also be built as a module. If so, the module
>  	  will be called ibmpowernv.
>  
> +config SENSORS_IBMPOWERNV_OCC
> +	tristate "IBM POWERNV OCC Inband platform sensors"
> +	depends on PPC_POWERNV
> +	default y
> +	help
> +	  If you say yes here you get support for the temperature/power
> +	  OCC inband sensors on your PowerNV platform.
> +
> +	  This driver can also be built as a module. If so, the module
> +	  will be called ibmpowernv-occ.
> +
>  config SENSORS_IIO_HWMON
>  	tristate "Hwmon driver that uses channels specified via iio maps"
>  	depends on IIO
> diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
> index 5509edf..0da2207 100644
> --- a/drivers/hwmon/Makefile
> +++ b/drivers/hwmon/Makefile
> @@ -75,6 +75,7 @@ obj-$(CONFIG_SENSORS_I5K_AMB)	+= i5k_amb.o
>  obj-$(CONFIG_SENSORS_IBMAEM)	+= ibmaem.o
>  obj-$(CONFIG_SENSORS_IBMPEX)	+= ibmpex.o
>  obj-$(CONFIG_SENSORS_IBMPOWERNV)+= ibmpowernv.o
> +obj-$(CONFIG_SENSORS_IBMPOWERNV_OCC)+= ibmpowernv-occ.o
>  obj-$(CONFIG_SENSORS_IIO_HWMON) += iio_hwmon.o
>  obj-$(CONFIG_SENSORS_INA209)	+= ina209.o
>  obj-$(CONFIG_SENSORS_INA2XX)	+= ina2xx.o
> diff --git a/drivers/hwmon/ibmpowernv-occ.c b/drivers/hwmon/ibmpowernv-occ.c
> new file mode 100644
> index 0000000..97b1bbe
> --- /dev/null
> +++ b/drivers/hwmon/ibmpowernv-occ.c
> @@ -0,0 +1,302 @@
> +/*
> + * IBM PowerNV platform OCC inband sensors for temperature/power
> + * Copyright (C) 2017 IBM
> + *
> + * 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.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program.
> + */
> +
> +#define DRVNAME		"ibmpowernv_occ"
> +#define pr_fmt(fmt)	DRVNAME ": " fmt
> +
> +#include <linux/module.h>
> +#include <linux/hwmon.h>
> +#include <linux/slab.h>
> +#include <linux/platform_device.h>
> +
> +#include <asm/opal.h>
> +
> +#define MAX_HWMON_ATTR_LEN	32
> +#define MAX_HWMON_LABEL_LEN	(MAX_OCC_SENSOR_NAME_LEN * 2)
> +#define HWMON_ATTRS_PER_SENSOR	16
> +#define TO_MILLI_UNITS(x)	((x) * 1000)
> +#define TO_MICRO_UNITS(x)	((x) * 1000000)
> +
> +enum sensors {
> +	TEMP,
> +	POWER,
> +	MAX_SENSOR_TYPE,
> +};
> +
> +static struct sensor_type {
> +	const char *name;
> +	int hwmon_id;
> +} sensor_types[] = {
> +	{ "temp"},
> +	{ "power"},
> +};
> +
> +static struct sensor_data {
> +	u32 occ_id;
> +	u64 offset;  /* Offset to ping/pong reading buffer */
> +	enum sensors type;
> +	char label[MAX_HWMON_LABEL_LEN];
> +	char name[MAX_HWMON_ATTR_LEN];
> +	struct device_attribute attr;
> +} *sdata;
> +
> +static struct attribute_group sensor_attrs_group;
> +__ATTRIBUTE_GROUPS(sensor_attrs);
> +
> +#define show(file_name)							\
> +static ssize_t ibmpowernv_occ_show_##file_name				\
> +(struct device *dev, struct device_attribute *dattr, char *buf)		\
> +{									\
> +	struct sensor_data *sdata = container_of(dattr,			\
> +						 struct sensor_data,	\
> +						 attr);			\
> +	u64 val;							\
> +	int ret;							\
> +	ret = opal_occ_sensor_get_##file_name(sdata->occ_id,		\
> +					      sdata->offset,		\
> +					      &val);			\
> +	if (ret)							\
> +		return ret;						\
> +	if (sdata->type == TEMP)					\
> +		val = TO_MILLI_UNITS(val);				\
> +	else if (sdata->type == POWER)					\
> +		val = TO_MICRO_UNITS(val);				\
> +	return sprintf(buf, "%llu\n", val);				\
> +}
> +
> +show(sample);
> +show(max);
> +show(min);
> +show(js_min);
> +show(js_max);
> +show(csm_min);
> +show(csm_max);
> +show(prof_min);
> +show(prof_max);
> +
> +static struct sensor_view_groups {
> +	const char *name;
> +	ssize_t (*show_sample)(struct device *dev,
> +			       struct device_attribute *attr,
> +			       char *buf);
> +	ssize_t (*show_min)(struct device *dev,
> +			    struct device_attribute *attr,
> +			    char *buf);
> +	ssize_t (*show_max)(struct device *dev,
> +			    struct device_attribute *attr,
> +			    char *buf);
> +} sensor_views[] = {
> +	{
> +		.name		= "",
> +		.show_sample	= ibmpowernv_occ_show_sample,
> +		.show_min	= ibmpowernv_occ_show_min,
> +		.show_max	= ibmpowernv_occ_show_max
> +	},
> +	{
> +		.name		= "_JS",
> +		.show_sample	= ibmpowernv_occ_show_sample,
> +		.show_min	= ibmpowernv_occ_show_js_min,
> +		.show_max	= ibmpowernv_occ_show_js_max
> +	},
> +	{	.name		= "_CSM",
> +		.show_sample	= ibmpowernv_occ_show_sample,
> +		.show_min	= ibmpowernv_occ_show_csm_min,
> +		.show_max	= ibmpowernv_occ_show_csm_max
> +	},
> +	{	.name		= "_Prof",
> +		.show_sample	= ibmpowernv_occ_show_sample,
> +		.show_min	= ibmpowernv_occ_show_prof_min,
> +		.show_max	= ibmpowernv_occ_show_prof_max
> +	},
> +};
> +
> +static ssize_t ibmpowernv_occ_show_label(struct device *dev,
> +					 struct device_attribute *dattr,
> +					 char *buf)
> +{
> +	struct sensor_data *sdata = container_of(dattr, struct sensor_data,
> +						 attr);
> +
> +	return sprintf(buf, "%s\n", sdata->label);
> +}
> +
> +static int ibmpowernv_occ_get_sensor_type(enum occ_sensor_type type)
> +{
> +	switch (type) {
> +	case OCC_SENSOR_TYPE_POWER:
> +		return POWER;
> +	case OCC_SENSOR_TYPE_TEMPERATURE:
> +		return TEMP;
> +	default:
> +		return MAX_SENSOR_TYPE;
> +	}
> +
> +	return MAX_SENSOR_TYPE;
> +}
> +
> +static void ibmpowernv_occ_add_sdata(struct occ_hwmon_sensor sensor,
> +				     struct sensor_data *sdata, char *name,
> +				     int hwmon_id, enum sensors type,
> +				     ssize_t (*show)(struct device *dev,
> +						struct device_attribute *attr,
> +						char *buf))
> +{
> +	sdata->type = type;
> +	sdata->occ_id = sensor.occ_id;
> +	sdata->offset = sensor.offset;
> +	snprintf(sdata->name, MAX_HWMON_ATTR_LEN, "%s%d_%s",
> +		 sensor_types[type].name, hwmon_id, name);
> +	sysfs_attr_init(&sdata->attr.attr);
> +	sdata->attr.attr.name = sdata->name;
> +	sdata->attr.attr.mode = 0444;
> +	sdata->attr.show = show;
> +}
> +
> +static void ibmpowernv_occ_add_sensor_attrs(struct occ_hwmon_sensor sensor,
> +					    int index)
> +{
> +	struct attribute **attrs = sensor_attrs_group.attrs;
> +	char attr_str[MAX_HWMON_ATTR_LEN];
> +	enum sensors type = ibmpowernv_occ_get_sensor_type(sensor.type);
> +	int i;
> +
> +	index *= HWMON_ATTRS_PER_SENSOR;
> +	for (i = 0; i < ARRAY_SIZE(sensor_views); i++) {
> +		int hid = ++sensor_types[type].hwmon_id;
> +
> +		/* input */
> +		ibmpowernv_occ_add_sdata(sensor, &sdata[index], "input", hid,
> +					 type, sensor_views[i].show_sample);
> +		attrs[index] = &sdata[index].attr.attr;
> +		index++;
> +
> +		/* min */
> +		if (type == POWER)
> +			snprintf(attr_str, MAX_HWMON_ATTR_LEN, "%s",
> +				 "input_lowest");
> +		else
> +			snprintf(attr_str, MAX_HWMON_ATTR_LEN, "%s", "min");
> +
> +		ibmpowernv_occ_add_sdata(sensor, &sdata[index], attr_str, hid,
> +					 type, sensor_views[i].show_min);
> +		attrs[index] = &sdata[index].attr.attr;
> +		index++;
> +
> +		/* max */
> +		if (type == POWER)
> +			snprintf(attr_str, MAX_HWMON_ATTR_LEN, "%s",
> +				 "input_highest");
> +		else
> +			snprintf(attr_str, MAX_HWMON_ATTR_LEN, "%s", "max");
> +
> +		ibmpowernv_occ_add_sdata(sensor, &sdata[index], attr_str, hid,
> +					 type, sensor_views[i].show_max);
> +		attrs[index] = &sdata[index].attr.attr;
> +		index++;
> +
> +		/* label */
> +		snprintf(sdata[index].label, MAX_HWMON_LABEL_LEN, "%s%s",
> +			 sensor.name, sensor_views[i].name);
> +		ibmpowernv_occ_add_sdata(sensor, &sdata[index], "label", hid,
> +					 type, ibmpowernv_occ_show_label);
> +		attrs[index] = &sdata[index].attr.attr;
> +		index++;
> +	}
> +}
> +
> +static int ibmpowernv_occ_add_device_attrs(struct platform_device *pdev)
> +{
> +	struct attribute **attrs;
> +	struct occ_hwmon_sensor *slist = NULL;
> +	int nr_sensors = 0, i;
> +	int ret = -ENOMEM;
> +
> +	slist = opal_occ_sensor_get_hwmon_list(&nr_sensors);
> +	if (!nr_sensors)
> +		return -ENODEV;
> +
> +	if (!slist)
> +		return ret;
> +
> +	sdata = devm_kzalloc(&pdev->dev, nr_sensors * sizeof(*sdata) *
> +			     HWMON_ATTRS_PER_SENSOR, GFP_KERNEL);
> +	if (!sdata)
> +		goto out;
> +
> +	attrs = devm_kzalloc(&pdev->dev, nr_sensors * sizeof(*attrs) *
> +			     HWMON_ATTRS_PER_SENSOR, GFP_KERNEL);
> +	if (!attrs)
> +		goto out;
> +
> +	sensor_attrs_group.attrs = attrs;
> +	for (i = 0; i < nr_sensors; i++)
> +		ibmpowernv_occ_add_sensor_attrs(slist[i], i);
> +
> +	ret = 0;
> +out:
> +	kfree(slist);
> +	return ret;
> +}
> +
> +static int ibmpowernv_occ_probe(struct platform_device *pdev)
> +{
> +	struct device *hwmon_dev;
> +	int err;
> +
> +	err = ibmpowernv_occ_add_device_attrs(pdev);
> +	if (err)
> +		goto out;
> +
> +	hwmon_dev = devm_hwmon_device_register_with_groups(&pdev->dev, DRVNAME,
> +							   NULL,
> +							   sensor_attrs_groups);
> +
> +	err = PTR_ERR_OR_ZERO(hwmon_dev);
> +out:
> +	if (err)
> +		pr_warn("Failed to initialize Hwmon OCC inband sensors\n");
> +
> +	return err;
> +}
> +
> +static const struct platform_device_id occ_sensor_ids[] = {
> +	{ .name = "occ-inband-sensor" },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(platform, occ_sensor_ids);
> +
> +static const struct of_device_id occ_sensor_of_ids[] = {
> +	{ .compatible	= "ibm,p9-occ-inband-sensor" },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(of, occ_sensor_of_ids);
> +
> +static struct platform_driver ibmpowernv_occ_driver = {
> +	.probe		= ibmpowernv_occ_probe,
> +	.id_table	= occ_sensor_ids,
> +	.driver		= {
> +		.name	= DRVNAME,
> +		.of_match_table	= occ_sensor_of_ids,
> +	},
> +};
> +
> +module_platform_driver(ibmpowernv_occ_driver);
> +
> +MODULE_AUTHOR("Shilpasri G Bhat <shilpa.bhat@xxxxxxxxxxxxxxxxxx>");
> +MODULE_DESCRIPTION("IBM POWERNV platform OCC inband sensors");
> +MODULE_LICENSE("GPL");
> -- 
> 1.8.3.1
>