[PATCH] powerpc/powernv: hwmon driver for power values, fan rpm and temperature
Neelesh Gupta
neelegup at linux.vnet.ibm.com
Mon May 19 04:08:17 EST 2014
On 05/14/2014 10:39 PM, Guenter Roeck wrote:
> On Wed, May 14, 2014 at 11:31:53AM +0530, Neelesh Gupta wrote:
>> This patch adds basic kernel enablement for reading power values, fan
>> speed rpm and temperature values on powernv platforms which will
>> be exported to user space through sysfs interface.
>>
>> Test results:
>> -------------
>> [root at tul163p1 ~]# sensors
>> ibmpowernv-isa-0000
>> Adapter: ISA adapter
>> fan1: 5294 RPM (min = 0 RPM)
>> fan2: 4945 RPM (min = 0 RPM)
>> fan3: 5831 RPM (min = 0 RPM)
>> fan4: 5212 RPM (min = 0 RPM)
>> fan5: 0 RPM (min = 0 RPM)
>> fan6: 0 RPM (min = 0 RPM)
>> fan7: 7472 RPM (min = 0 RPM)
>> fan8: 7920 RPM (min = 0 RPM)
>> temp1: +39.0°C (high = +0.0°C)
>> power1: 192.00 W
>>
>> [root at tul163p1 ~]#
>> [root at tul163p1 ~]# ls /sys/devices/platform/ibmpowernv.0/
>> driver fan2_min fan4_min fan6_min fan8_min modalias uevent
>> fan1_fault fan3_fault fan5_fault fan7_fault hwmon name
>> fan1_input fan3_input fan5_input fan7_input in1_fault power1_input
>> fan1_min fan3_min fan5_min fan7_min in2_fault subsystem
>> fan2_fault fan4_fault fan6_fault fan8_fault in3_fault temp1_input
>> fan2_input fan4_input fan6_input fan8_input in4_fault temp1_max
>> [root at tul163p1 ~]#
>> [root at tul163p1 ~]# ls /sys/class/hwmon/hwmon0/device/
>> driver fan2_min fan4_min fan6_min fan8_min modalias uevent
>> fan1_fault fan3_fault fan5_fault fan7_fault hwmon name
>> fan1_input fan3_input fan5_input fan7_input in1_fault power1_input
>> fan1_min fan3_min fan5_min fan7_min in2_fault subsystem
>> fan2_fault fan4_fault fan6_fault fan8_fault in3_fault temp1_input
>> fan2_input fan4_input fan6_input fan8_input in4_fault temp1_max
>> [root at tul163p1 ~]#
>>
>> Signed-off-by: Shivaprasad G Bhat <sbhat at linux.vnet.ibm.com>
>> Signed-off-by: Neelesh Gupta <neelegup at linux.vnet.ibm.com>
>> ---
>> drivers/hwmon/Kconfig | 8 +
>> drivers/hwmon/Makefile | 1
>> drivers/hwmon/ibmpowernv.c | 386 ++++++++++++++++++++++++++++++++++++++++++++
>> 3 files changed, 395 insertions(+)
>> create mode 100644 drivers/hwmon/ibmpowernv.c
>>
>> diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
>> index bc196f4..3e308fa 100644
>> --- a/drivers/hwmon/Kconfig
>> +++ b/drivers/hwmon/Kconfig
>> @@ -554,6 +554,14 @@ config SENSORS_IBMPEX
>> This driver can also be built as a module. If so, the module
>> will be called ibmpex.
>>
>> +config SENSORS_IBMPOWERNV
>> + tristate "IBM POWERNV platform sensors"
>> + depends on PPC_POWERNV
>> + default y
>> + help
>> + If you say yes here you get support for the temperature/fan/power
>> + sensors on your platform.
>> +
>> 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 c48f987..199c401 100644
>> --- a/drivers/hwmon/Makefile
>> +++ b/drivers/hwmon/Makefile
>> @@ -71,6 +71,7 @@ obj-$(CONFIG_SENSORS_ULTRA45) += ultra45_env.o
>> obj-$(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_IIO_HWMON) += iio_hwmon.o
>> obj-$(CONFIG_SENSORS_INA209) += ina209.o
>> obj-$(CONFIG_SENSORS_INA2XX) += ina2xx.o
>> diff --git a/drivers/hwmon/ibmpowernv.c b/drivers/hwmon/ibmpowernv.c
>> new file mode 100644
>> index 0000000..e5cffce
>> --- /dev/null
>> +++ b/drivers/hwmon/ibmpowernv.c
>> @@ -0,0 +1,386 @@
>> +/*
>> + * IBM PowerNV platform sensors for temperature/fan/power
>> + * Copyright (C) 2014 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; if not, write to the Free Software
>> + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
> Please drop the FSF address; it can change, and we don't want to update the
> driver each time it does.
>
>> + */
>> +
>> +#include <linux/init.h>
>> +#include <linux/module.h>
>> +#include <linux/kernel.h>
>> +#include <linux/hwmon.h>
>> +#include <linux/hwmon-sysfs.h>
>> +#include <linux/of.h>
>> +#include <linux/slab.h>
>> +
>> +#include <linux/platform_device.h>
>> +#include <asm/opal.h>
>> +#include <linux/err.h>
>> +
>> +#define DRVNAME "ibmpowernv"
>> +#define MAX_ATTR_LEN 32
>> +
>> +/* Sensor suffix name from DT */
>> +#define DT_FAULT_ATTR_SUFFIX "faulted"
>> +#define DT_DATA_ATTR_SUFFIX "data"
>> +#define DT_THRESHOLD_ATTR_SUFFIX "thrs"
>> +
>> +/* Enumerates all the sensors in the POWERNV platform and also index into
>> + * 'struct sensor_name'
> Comment coding style, please (this is not the networking subsystem ;-)
>
>> + */
>> +enum sensors {
>> + FAN,
>> + AMBIENT_TEMP,
>> + POWERSUPPLY,
>> + POWER,
>> + MAX_SENSOR_TYPE,
>> +};
>> +
>> +static struct sensor_name {
> const ?
>
>> + char *name;
>> + char *compatible;
>> +} sensor_names[] = {
>> + {"fan", "ibm,opal-sensor-cooling-fan"},
>> + {"temp", "ibm,opal-sensor-amb-temp"},
>> + {"in", "ibm,opal-sensor-power-supply"},
>> + {"power", "ibm,opal-sensor-power"}
>> +};
>> +
>> +struct platform_data {
>> + struct device *hwmon_dev;
> Not needed.
>
>> + struct device_attribute name_attr;
>> + struct list_head attr_list;
>> +};
>> +
>> +struct sensor_data {
>> + u32 id;
>> + enum sensors stype;
>> + char name[MAX_ATTR_LEN];
>> + struct sensor_device_attribute sd_attr;
>> + struct list_head list;
>> +};
>> +
>> +/* Platform device representing all the ibmpowernv sensors */
>> +static struct platform_device *pdevice;
>> +
>> +static void get_sensor_index_attr(const char *name, u32 *index, char *attr)
>> +{
>> + char *hash_pos = strchr(name, '#');
>> + char *dash_pos;
>> + u32 copy_len;
>> + char buf[8];
>> +
>> + memset(buf, 0, sizeof(buf));
>> + *index = 0;
>> + *attr = '\0';
>> +
>> + if (hash_pos) {
>> + dash_pos = strchr(hash_pos, '-');
>> + if (dash_pos) {
>> + copy_len = dash_pos - hash_pos - 1;
>> + if (copy_len < sizeof(buf)) {
>> + strncpy(buf, hash_pos + 1, copy_len);
>> + sscanf(buf, "%d", index);
>> + }
>> +
>> + strncpy(attr, dash_pos + 1, MAX_ATTR_LEN);
>> + }
>> + }
>> +}
>> +
>> +/*
>> + * This function translates the DT node name into the 'hwmon' attribute name.
>> + * IBMPOWERNV device node appear like cooling-fan#2-data, amb-temp#1-thrs etc.
>> + * which need to be mapped as fan2_input, temp1_max respectively before
>> + * populating them inside hwmon device class..
>> + */
>> +static int create_hwmon_attr_name(enum sensors stype, const char *node_name,
>> + char *hwmon_attr_name)
> Please follow CodingStyle for continuation line alignment.
>
>> +{
>> + char attr_suffix[MAX_ATTR_LEN];
>> + char *attr_name;
>> + u32 index;
>> +
>> + get_sensor_index_attr(node_name, &index, attr_suffix);
>> + if (!index || !strlen(attr_suffix)) {
>> + pr_info("%s: Sensor device node name is invalid, name: %s\n",
>> + __func__, node_name);
>> + return -EINVAL;
>> + }
>> +
>> + if (!strcmp(attr_suffix, DT_FAULT_ATTR_SUFFIX))
>> + attr_name = "fault";
>> + else if(!strcmp(attr_suffix, DT_DATA_ATTR_SUFFIX))
>> + attr_name = "input";
>> + else if (!strcmp(attr_suffix, DT_THRESHOLD_ATTR_SUFFIX)) {
>> + if (stype == AMBIENT_TEMP)
>> + attr_name = "max";
>> + else if (stype == FAN)
>> + attr_name = "min";
>> + else
>> + return -ENOENT;
>> + } else
>> + return -ENOENT;
>> +
>> + snprintf(hwmon_attr_name, MAX_ATTR_LEN, "%s%d_%s",
>> + sensor_names[stype].name, index, attr_name);
>> + return 0;
>> +}
>> +
>> +static ssize_t show_sensor(struct device *dev, struct device_attribute *devattr,
>> + char *buf)
>> +{
>> + struct sensor_device_attribute *sd_attr = to_sensor_dev_attr(devattr);
>> + struct sensor_data *sdata = container_of(sd_attr, struct sensor_data,
>> + sd_attr);
>> + int err;
>> + u32 x;
>> +
>> + err = opal_get_sensor_data(sdata->id, &x);
>> + if (err) {
>> + pr_err("%s: Failed to get opal sensor data\n", __func__);
>> + x = -1;
> Unusual. Why not report the error to user space ?
> Reporting <maxuint> on error doesn't seem to be very useful.
>
>> + }
>> +
>> + /* Convert temperature to milli-degrees */
>> + if (sdata->stype == AMBIENT_TEMP && x > 0)
>> + x *= 1000;
>> + /* Convert power to micro-watts */
>> + else if (sdata->stype == POWER && x > 0)
>> + x *= 1000000;
>> +
> Is there an overflow concern ? Guess not ... overflow happens at ~17KW.
> Just wondering.
>
>> + return sprintf(buf, "%d\n", x);
>> +}
>> +
>> +static void remove_device_attrs(struct platform_device *pdev)
>> +{
>> + struct platform_data *pdata = platform_get_drvdata(pdev);
>> + struct device *dev = &pdev->dev;
>> + struct sensor_data *s, *next;
>> +
>> + list_for_each_entry_safe(s, next, &pdata->attr_list, list) {
>> + device_remove_file(dev, &s->sd_attr.dev_attr);
>> + list_del(&s->list);
> This is unnecessary since you always remove the entire list anyway.
> Actually, I don't think you need the list in the first place.
> You only use it to delete entries, but that can be handled automatically
> by the infrastructure. All you really need is an array pointing to the device
> attributes so you can create all attribute files with a single operation.
>
>> + kfree(s);
>> + }
>> +}
>> +
>> +/*
>> + * Iterate through the device tree and for each child of sensor node, create
>> + * a sysfs attribute file, the file is named by translating the DT node name
>> + * to the name required by the higher 'hwmon' driver like fan1_input, temp1_max
>> + * etc..
>> + */
>> +static int create_device_attrs(struct platform_device *pdev)
>> +{
>> + struct platform_data *pdata = platform_get_drvdata(pdev);
>> + struct device *dev = &pdev->dev;
>> + struct device_node *opal, *np;
>> + struct sensor_data *sdata;
>> + const u32 *sensor_id;
>> + enum sensors stype;
>> + int err;
>> +
>> + opal = of_find_node_by_path("/ibm,opal/sensors");
>> + if (!opal) {
>> + pr_err("%s: Opal 'sensors' node not found\n", __func__);
>> + err = -ENXIO;
> ENODEV ?
>
>> + goto exit;
> I would suggest to simply return here.
>
>> + }
>> +
>> + for_each_child_of_node(opal, np) {
>> + if (np->name == NULL)
>> + continue;
>> +
>> + for (stype = 0; stype < MAX_SENSOR_TYPE; stype++)
>> + if (of_device_is_compatible(np,
>> + sensor_names[stype].compatible))
>> + break;
>> +
>> + if (stype == MAX_SENSOR_TYPE)
>> + continue;
>> +
>> + sensor_id = of_get_property(np, "sensor-id", NULL);
>> + if (!sensor_id) {
>> + pr_info("%s: %s doesn't have sensor-id\n", __func__,
>> + np->name);
>> + continue;
>> + }
>> +
>> + sdata = kzalloc(sizeof(*sdata), GFP_KERNEL);
> Can you use devm_kzalloc() ?
>
>> + if (!sdata) {
>> + pr_err("%s: Failed to allocate memory for sensor_data",
>> + __func__);
>> + err = -ENOMEM;
>> + goto exit_put_node;
>> + }
>> +
>> + sdata->id = *sensor_id;
>> + sdata->stype = stype;
>> + err = create_hwmon_attr_name(stype, np->name, sdata->name);
>> + if (err) {
>> + pr_err("%s: Failed to create the hwmon attribute name\n",
>> + __func__);
> create_hwmon_attr_name() (sometimes) already creates an error message.
> Would be nice if you can avoid duplicate error messages.
>
>> + goto exit_free_sdata;
>> + }
>> +
>> + sysfs_attr_init(&sdata->sd_attr.dev_attr.attr);
>> + sdata->sd_attr.dev_attr.attr.name = sdata->name;
>> + sdata->sd_attr.dev_attr.attr.mode = S_IRUGO;
>> + sdata->sd_attr.dev_attr.show = show_sensor;
> Since you are not using the index value from sensor_device_attribute,
> but use your own 'id' variable instead, you don't need sensor_device_attribute
> but can use device_attribute instead (or drop 'id' and use
> sd_attr.index instead).
>
>> +
>> + /* Create sysfs attribute file */
>> + err = device_create_file(dev, &sdata->sd_attr.dev_attr);
>> + if (err)
>> + goto exit_free_sdata;
>> +
> Please don't create the attribute files here but just a list of attributes
> instead. See below for more details.
>
>> + list_add_tail(&sdata->list, &pdata->attr_list);
>> + }
>> +
>> + of_node_put(opal);
>> + return 0;
>> +
>> +exit_free_sdata:
>> + kfree(sdata);
>> +exit_put_node:
>> + of_node_put(opal);
>> + remove_device_attrs(pdev);
>> +exit:
>> + return err;
>> +}
>> +
>> +static ssize_t show_name(struct device *dev, struct device_attribute *devattr,
>> + char *buf)
>> +{
>> + struct platform_device *pdev = to_platform_device(dev);
>> + return sprintf(buf, "%s\n", pdev->name);
>> +}
> Not necessary; see below.
>
>> +
>> +static int ibmpowernv_probe(struct platform_device *pdev)
>> +{
>> + struct device *dev = &pdev->dev;
>> + struct platform_data *pdata;
>> + int err;
>> +
>> + pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
>> + if (!pdata) {
>> + err = -ENOMEM;
>> + goto exit;
>> + }
>> +
>> + INIT_LIST_HEAD(&pdata->attr_list);
>> + platform_set_drvdata(pdev, pdata);
>> +
>> + /* Create platform device 'name' attribute */
>> + sysfs_attr_init(&pdata->name_attr.attr);
>> + pdata->name_attr.attr.name = "name";
>> + pdata->name_attr.attr.mode = S_IRUGO;
>> + pdata->name_attr.show = show_name;
>> + err = device_create_file(dev, &pdata->name_attr);
> You don't need to create a name attribute.
> devm_hwmon_device_register_with_groups does it for you (from the second
> argument).
>
>> + if (err)
>> + goto exit;
>> +
>> + /* Create sysfs attribute file for each sensor found in the DT */
>> + err = create_device_attrs(pdev);
> That defeats the purpose of using devm_hwmon_device_register_with_groups.
> The idea here is to build a list of attributes, which you can do in
> create_device_attrs(), but not create the actual device entries.
> Then also create an attribute_group as well as a list of groups,
> and pass that as last argument to devm_hwmon_device_register_with_groups().
>
> drivers/hwmon/pmbus/pmbus_core.c does something similar; maybe you can
> use a similar approach.
>
> With that, you also don't need the remove functions, since the hwmon
> subsystem will auto-remove the attributes. If you do it correctly
> (ie use devm_kzalloc() for allocating memory) you should not need a
> remove function at all.
>
>> + if (err) {
>> + pr_err("%s: Failed to create the device attributes\n",
>> + __func__);
>> + goto exit_remove_name;
>> + }
>> +
>> + /* Finally, register with hwmon */
>> + pdata->hwmon_dev = devm_hwmon_device_register_with_groups(dev, DRVNAME,
>> + pdata, NULL);
>> + if (IS_ERR(pdata->hwmon_dev)) {
>> + err = PTR_ERR(pdata->hwmon_dev);
>> + goto exit_remove_devattrs;
>> + }
>> +
>> + return 0;
>> +
>> +exit_remove_devattrs:
>> + remove_device_attrs(pdev);
>> +exit_remove_name:
>> + device_remove_file(dev, &pdata->name_attr);
>> +exit:
>> + return err;
> If you do it right you should be able to reduce this to something like
>
> hwmon_dev = devm_hwmon_device_register_with_groups(dev, DRVNAME, pdata,
> pdata->attr_groups);
> return PTR_ERR_OR_ZERO(hwmon_dev);
>
> ...
>
>> +}
>> +
>> +static int ibmpowernv_remove(struct platform_device *pdev)
>> +{
>> + struct platform_data *pdata = platform_get_drvdata(pdev);
>> + struct device *dev = &pdev->dev;
>> +
>> + remove_device_attrs(pdev);
>> + device_remove_file(dev, &pdata->name_attr);
>> +
>> + return 0;
>> +}
> ... and you should be able to remove this entire function.
>
>> +
>> +
> No double empty lines please.
>
>> +static struct platform_driver ibmpowernv_driver = {
>> + .driver = {
>> + .owner = THIS_MODULE,
>> + .name = DRVNAME,
>> + },
>> + .probe = ibmpowernv_probe,
>> + .remove = ibmpowernv_remove,
>> +};
>> +
>> +
> Excessive empty lines.
>
>> +static int __init ibmpowernv_init(void)
>> +{
>> + int err;
>> +
>> +
> Excessive empty lines.
>
>> + err = platform_driver_register(&ibmpowernv_driver);
>> + if (err)
>> + goto exit;
> Sometimes you create an error message, sometimes not. I'd prefer no error
> message to start with (the module loader will create one anyway), but
> at least please be consistent.
>
>> +
>> +
> Excessive empty lines.
>
>> + pdevice = platform_device_alloc(DRVNAME, 0);
>> + if (!pdevice) {
>> + pr_err("%s: Device allocation failed\n", __func__);
>> + err = -ENOMEM;
>> + goto exit_driver_unreg;
>> + }
>> +
>> + err = platform_device_add(pdevice);
>> + if (err) {
>> + pr_err("%s: Device addition failed (%d)\n", __func__, err);
>> + goto exit_device_put;
>> + }
>> +
> Can you use platform_driver_probe() here ?
>
>> + return 0;
>> +
>> +exit_device_put:
>> + platform_device_put(pdevice);
>> +exit_driver_unreg:
>> + platform_driver_unregister(&ibmpowernv_driver);
>> +exit:
>> + return err;
>> +}
>> +
>> +static void __exit ibmpowernv_exit(void)
>> +{
>> + platform_device_unregister(pdevice);
>> + platform_driver_unregister(&ibmpowernv_driver);
>> +}
>> +
>> +MODULE_DESCRIPTION("IBM POWERNV platform sensors");
>> +MODULE_LICENSE("GPL");
>> +
>> +module_init(ibmpowernv_init);
>> +module_exit(ibmpowernv_exit);
>>
>>
> Empty lines at end.
>
> _______________________________________________
> Linuxppc-dev mailing list
> Linuxppc-dev at lists.ozlabs.org
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Hi Guenter,
Thanks for the review. I'll rework on the patch and post the v2.
- Neelesh
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