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References: <20190813083412.8668-1-wangzqbj@inspur.com> <70B3A211-2F43-4712-9B92-D407AA3C3934@fb.com>
 <20190815194102.GA11916@roeck-us.net>
In-Reply-To: <20190815194102.GA11916@roeck-us.net>
From:   John Wang <wangzqbj@inspur.com>
Date:   Fri, 16 Aug 2019 10:44:01 +0800
Message-ID: <CAHkHK08ZkZDoVQ0qfLPcO=_=-OAmx+N5BGHRgZkoxLUNQzTp5g@mail.gmail.com>
Subject: Re: [PATCH v4 2/2] hwmon: pmbus: Add Inspur Power System power supply driver
To:     Guenter Roeck <linux@roeck-us.net>
CC:     Vijay Khemka <vijaykhemka@fb.com>,
        "linux-hwmon@vger.kernel.org" <linux-hwmon@vger.kernel.org>,
        "jdelvare@suse.com" <jdelvare@suse.com>,
        "linux-doc@vger.kernel.org" <linux-doc@vger.kernel.org>,
        "openbmc@lists.ozlabs.org" <openbmc@lists.ozlabs.org>,
        "corbet@lwn.net" <corbet@lwn.net>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "duanzhijia01@inspur.com" <duanzhijia01@inspur.com>
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Sender: linux-kernel-owner@vger.kernel.org
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On Fri, Aug 16, 2019 at 3:41 AM Guenter Roeck <linux@roeck-us.net> wrote:
>
> On Thu, Aug 15, 2019 at 06:43:52PM +0000, Vijay Khemka wrote:
> >
> >
> > ﻿On 8/13/19, 1:36 AM, "openbmc on behalf of John Wang" <openbmc-bounces+vijaykhemka=fb.com@lists.ozlabs.org on behalf of wangzqbj@inspur.com> wrote:
> >
> >     Add the driver to monitor Inspur Power System power supplies
> >     with hwmon over pmbus.
> >
> >     This driver adds sysfs attributes for additional power supply data,
> >     including vendor, model, part_number, serial number,
> >     firmware revision, hardware revision, and psu mode(active/standby).
> >
> >     Signed-off-by: John Wang <wangzqbj@inspur.com>
> >     ---
> >     v4:
> >         - Remove the additional tabs in the Makefile
> >         - Rebased on 5.3-rc4, not 5.2
> >     v3:
> >         - Sort kconfig/makefile entries alphabetically
> >         - Remove unnecessary initialization
> >         - Use ATTRIBUTE_GROUPS instead of expanding directly
> >         - Use memscan to avoid reimplementation
> >     v2:
> >         - Fix typos in commit message
> >         - Invert Christmas tree
> >         - Configure device with sysfs attrs, not debugfs entries
> >         - Fix errno in fw_version_read, ENODATA to EPROTO
> >         - Change the print format of fw-version
> >         - Use sysfs_streq instead of strcmp("xxx" "\n", "xxx")
> >         - Document sysfs attributes
> >     ---
> >      Documentation/hwmon/inspur-ipsps1.rst |  79 +++++++++
> >      drivers/hwmon/pmbus/Kconfig           |   9 +
> >      drivers/hwmon/pmbus/Makefile          |   1 +
> >      drivers/hwmon/pmbus/inspur-ipsps.c    | 226 ++++++++++++++++++++++++++
> >      4 files changed, 315 insertions(+)
> >      create mode 100644 Documentation/hwmon/inspur-ipsps1.rst
> >      create mode 100644 drivers/hwmon/pmbus/inspur-ipsps.c
> >
> >     diff --git a/Documentation/hwmon/inspur-ipsps1.rst b/Documentation/hwmon/inspur-ipsps1.rst
> >     new file mode 100644
> >     index 000000000000..aa19f0ccc8b0
> >     --- /dev/null
> >     +++ b/Documentation/hwmon/inspur-ipsps1.rst
> >     @@ -0,0 +1,79 @@
> >     +Kernel driver inspur-ipsps1
> >     +=======================
> >     +
> >     +Supported chips:
> >     +
> >     +  * Inspur Power System power supply unit
> >     +
> >     +Author: John Wang <wangzqbj@inspur.com>
> >     +
> >     +Description
> >     +-----------
> >     +
> >     +This driver supports Inspur Power System power supplies. This driver
> >     +is a client to the core PMBus driver.
> >     +
> >     +Usage Notes
> >     +-----------
> >     +
> >     +This driver does not auto-detect devices. You will have to instantiate the
> >     +devices explicitly. Please see Documentation/i2c/instantiating-devices for
> >     +details.
> >     +
> >     +Sysfs entries
> >     +-------------
> >     +
> >     +The following attributes are supported:
> >     +
> >     +======================= ======================================================
> >     +curr1_input             Measured input current
> >     +curr1_label             "iin"
> >     +curr1_max               Maximum current
> >     +curr1_max_alarm         Current high alarm
> >     +curr2_input              Measured output current in mA.
> >     +curr2_label              "iout1"
> >     +curr2_crit              Critical maximum current
> >     +curr2_crit_alarm        Current critical high alarm
> >     +curr2_max               Maximum current
> >     +curr2_max_alarm         Current high alarm
> >     +
> > Please align above details.

Sorry for the mix of table and space

> >     +fan1_alarm               Fan 1 warning.
> >     +fan1_fault               Fan 1 fault.
> >     +fan1_input               Fan 1 speed in RPM.
> >     +
> >     +in1_alarm                Input voltage under-voltage alarm.
> >     +in1_input                Measured input voltage in mV.
> >     +in1_label                "vin"
> >     +in2_input                Measured output voltage in mV.
> >     +in2_label                "vout1"
> >     +in2_lcrit               Critical minimum output voltage
> >     +in2_lcrit_alarm         Output voltage critical low alarm
> >     +in2_max                 Maximum output voltage
> >     +in2_max_alarm           Output voltage high alarm
> >     +in2_min                 Minimum output voltage
> >     +in2_min_alarm           Output voltage low alarm
> >     +
> >     +power1_alarm             Input fault or alarm.
> >     +power1_input             Measured input power in uW.
> >     +power1_label             "pin"
> >     +power1_max              Input power limit
> >     +power2_max_alarm Output power high alarm
> >     +power2_max              Output power limit
> >     +power2_input             Measured output power in uW.
> >     +power2_label             "pout"
> >     +
> > Same alignment issue in description.

will fix.

> >     +temp[1-3]_input          Measured temperature
> >     +temp[1-2]_max            Maximum temperature
> >     +temp[1-3]_max_alarm      Temperature high alarm
> >     +
> >     +vendor                  Manufacturer name
> >     +model                   Product model
> >     +part_number             Product part number
> >     +serial_number           Product serial number
> >     +fw_version              Firmware version
> >     +hw_version              Hardware version
> >     +mode                    Work mode. Can be set to active or
> >     +                        standby, when set to standby, PSU will
> >     +                        automatically switch between standby
> >     +                        and redundancy mode.
> >     +======================= ======================================================
> >     diff --git a/drivers/hwmon/pmbus/Kconfig b/drivers/hwmon/pmbus/Kconfig
> >     index b6588483fae1..d62d69bb7e49 100644
> >     --- a/drivers/hwmon/pmbus/Kconfig
> >     +++ b/drivers/hwmon/pmbus/Kconfig
> >     @@ -46,6 +46,15 @@ config SENSORS_IBM_CFFPS
> >         This driver can also be built as a module. If so, the module will
> >         be called ibm-cffps.
> >
> >     +config SENSORS_INSPUR_IPSPS
> >     + tristate "INSPUR Power System Power Supply"
> >     + help
> >     +   If you say yes here you get hardware monitoring support for the INSPUR
> >     +   Power System power supply.
> >     +
> >     +   This driver can also be built as a module. If so, the module will
> >     +   be called inspur-ipsps.
> >     +
> >      config SENSORS_IR35221
> >       tristate "Infineon IR35221"
> >       help
> >     diff --git a/drivers/hwmon/pmbus/Makefile b/drivers/hwmon/pmbus/Makefile
> >     index c950ea9a5d00..03bacfcfd660 100644
> >     --- a/drivers/hwmon/pmbus/Makefile
> >     +++ b/drivers/hwmon/pmbus/Makefile
> >     @@ -7,6 +7,7 @@ obj-$(CONFIG_PMBUS)               += pmbus_core.o
> >      obj-$(CONFIG_SENSORS_PMBUS)      += pmbus.o
> >      obj-$(CONFIG_SENSORS_ADM1275)    += adm1275.o
> >      obj-$(CONFIG_SENSORS_IBM_CFFPS)  += ibm-cffps.o
> >     +obj-$(CONFIG_SENSORS_INSPUR_IPSPS) += inspur-ipsps.o
> >      obj-$(CONFIG_SENSORS_IR35221)    += ir35221.o
> >      obj-$(CONFIG_SENSORS_IR38064)    += ir38064.o
> >      obj-$(CONFIG_SENSORS_IRPS5401)   += irps5401.o
> >     diff --git a/drivers/hwmon/pmbus/inspur-ipsps.c b/drivers/hwmon/pmbus/inspur-ipsps.c
> >     new file mode 100644
> >     index 000000000000..fa981b881a60
> >     --- /dev/null
> >     +++ b/drivers/hwmon/pmbus/inspur-ipsps.c
> >     @@ -0,0 +1,226 @@
> >     +// SPDX-License-Identifier: GPL-2.0-or-later
> >     +/*
> >     + * Copyright 2019 Inspur Corp.
> >     + */
> >     +
> >     +#include <linux/debugfs.h>
> >     +#include <linux/device.h>
> >     +#include <linux/fs.h>
> >     +#include <linux/i2c.h>
> >     +#include <linux/module.h>
> >     +#include <linux/pmbus.h>
> >     +#include <linux/hwmon-sysfs.h>
> >     +
> >     +#include "pmbus.h"
> >     +
> >     +#define IPSPS_REG_VENDOR_ID      0x99
> >     +#define IPSPS_REG_MODEL          0x9A
> >     +#define IPSPS_REG_FW_VERSION     0x9B
> >     +#define IPSPS_REG_PN             0x9C
> >     +#define IPSPS_REG_SN             0x9E
> >     +#define IPSPS_REG_HW_VERSION     0xB0
> >     +#define IPSPS_REG_MODE           0xFC
> >     +
> >     +#define MODE_ACTIVE              0x55
> >     +#define MODE_STANDBY             0x0E
> >     +#define MODE_REDUNDANCY          0x00
> >     +
> >     +#define MODE_ACTIVE_STRING               "active"
> >     +#define MODE_STANDBY_STRING              "standby"
> >     +#define MODE_REDUNDANCY_STRING           "redundancy"
> >     +
> >     +enum ipsps_index {
> >     + vendor,
> >     + model,
> >     + fw_version,
> >     + part_number,
> >     + serial_number,
> >     + hw_version,
> >     + mode,
> >     + num_regs,
> >     +};
> >     +
> >     +static const u8 ipsps_regs[num_regs] = {
> >     + [vendor] = IPSPS_REG_VENDOR_ID,
> >     + [model] = IPSPS_REG_MODEL,
> >     + [fw_version] = IPSPS_REG_FW_VERSION,
> >     + [part_number] = IPSPS_REG_PN,
> >     + [serial_number] = IPSPS_REG_SN,
> >     + [hw_version] = IPSPS_REG_HW_VERSION,
> >     + [mode] = IPSPS_REG_MODE,
> >     +};
> >     +
> >     +static ssize_t ipsps_string_show(struct device *dev,
> >     +                          struct device_attribute *devattr,
> >     +                          char *buf)
> >     +{
> >     + u8 reg;
> >     + int rc;
> >     + char *p;
> >     + char data[I2C_SMBUS_BLOCK_MAX + 1];
> >     + struct i2c_client *client = to_i2c_client(dev->parent);
> >     + struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
> >     +
> >     + reg = ipsps_regs[attr->index];
> >     + rc = i2c_smbus_read_block_data(client, reg, data);
> >     + if (rc < 0)
> >     +         return rc;
> >     +
> >     + /* filled with printable characters, ending with # */
> >     + p = memscan(data, '#', rc);
> >     + *p = '\0';
> >     +
> >     + return snprintf(buf, PAGE_SIZE, "%s\n", data);
> >     +}
> >     +
> >     +static ssize_t ipsps_fw_version_show(struct device *dev,
> >     +                              struct device_attribute *devattr,
> >     +                              char *buf)
> >     +{
> >     + u8 reg;
> >     + int rc;
> >     + u8 data[I2C_SMBUS_BLOCK_MAX] = { 0 };
> >     + struct i2c_client *client = to_i2c_client(dev->parent);
> >     + struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
> >     +
> >     + reg = ipsps_regs[attr->index];
> >     + rc = i2c_smbus_read_block_data(client, reg, data);
> >     + if (rc < 0)
> >     +         return rc;
> >     +
> >     + if (rc != 6)
> >     +         return -EPROTO;
> >     +
> >     + return snprintf(buf, PAGE_SIZE, "%u.%02u%u-%u.%02u\n",
> >     +                 data[1], data[2]/* < 100 */, data[3]/*< 10*/,
> >     +                 data[4], data[5]/* < 100 */);
> >     +}
> >     +
> >     +static ssize_t ipsps_mode_show(struct device *dev,
> >     +                        struct device_attribute *devattr, char *buf)
> >     +{
> >     + u8 reg;
> >     + int rc;
> >     + struct i2c_client *client = to_i2c_client(dev->parent);
> >     + struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
> >     +
> >     + reg = ipsps_regs[attr->index];
> >     + rc = i2c_smbus_read_byte_data(client, reg);
> >     + if (rc < 0)
> >     +         return rc;
> >     +
> >     + switch (rc) {
> >     + case MODE_ACTIVE:
> >     +         return snprintf(buf, PAGE_SIZE, "[%s] %s %s\n",
> >     +                         MODE_ACTIVE_STRING,
> >     +                         MODE_STANDBY_STRING, MODE_REDUNDANCY_STRING);
> >     + case MODE_STANDBY:
> >     +         return snprintf(buf, PAGE_SIZE, "%s [%s] %s\n",
> >     +                         MODE_ACTIVE_STRING,
> >     +                         MODE_STANDBY_STRING, MODE_REDUNDANCY_STRING);
> >     + case MODE_REDUNDANCY:
> >     +         return snprintf(buf, PAGE_SIZE, "%s %s [%s]\n",
> >     +                         MODE_ACTIVE_STRING,
> >     +                         MODE_STANDBY_STRING, MODE_REDUNDANCY_STRING);
> >     + default:
> >     +         return snprintf(buf, PAGE_SIZE, "unspecified\n");
> >     + }
> >     +}
> >     +
> >     +static ssize_t ipsps_mode_store(struct device *dev,
> >     +                         struct device_attribute *devattr,
> >     +                         const char *buf, size_t count)
> >     +{
> >     + u8 reg;
> >     + int rc;
> >     + struct i2c_client *client = to_i2c_client(dev->parent);
> >     + struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
> >     +
> >     + reg = ipsps_regs[attr->index];
> >     + if (sysfs_streq(MODE_STANDBY_STRING, buf)) {
> >     +         rc = i2c_smbus_write_byte_data(client, reg,
> >     +                                        MODE_STANDBY);
> >     +         if (rc < 0)
> >     +                 return rc;
> >     +         return count;
> >     + } else if (sysfs_streq(MODE_ACTIVE_STRING, buf)) {
> >     +         rc = i2c_smbus_write_byte_data(client, reg,
> >     +                                        MODE_ACTIVE);
> >     +         if (rc < 0)
> >     +                 return rc;
> >     +         return count;
> >     + }
> >     +
> >     + return -EINVAL;
> >     +}
> >     +
> >     +static SENSOR_DEVICE_ATTR_RO(vendor, ipsps_string, vendor);
> >     +static SENSOR_DEVICE_ATTR_RO(model, ipsps_string, model);
> >     +static SENSOR_DEVICE_ATTR_RO(part_number, ipsps_string, part_number);
> >     +static SENSOR_DEVICE_ATTR_RO(serial_number, ipsps_string, serial_number);
> >     +static SENSOR_DEVICE_ATTR_RO(hw_version, ipsps_string, hw_version);
> >     +static SENSOR_DEVICE_ATTR_RO(fw_version, ipsps_fw_version, fw_version);
> >     +static SENSOR_DEVICE_ATTR_RW(mode, ipsps_mode, mode);
> >     +
> >     +static struct attribute *ipsps_attrs[] = {
> >     + &sensor_dev_attr_vendor.dev_attr.attr,
> >     + &sensor_dev_attr_model.dev_attr.attr,
> >     + &sensor_dev_attr_part_number.dev_attr.attr,
> >     + &sensor_dev_attr_serial_number.dev_attr.attr,
> >     + &sensor_dev_attr_hw_version.dev_attr.attr,
> >     + &sensor_dev_attr_fw_version.dev_attr.attr,
> >     + &sensor_dev_attr_mode.dev_attr.attr,
> >     + NULL,
> >     +};
> >     +
> >     +ATTRIBUTE_GROUPS(ipsps);
> >     +
> >     +static struct pmbus_driver_info ipsps_info = {
> >     + .pages = 1,
> >     + .func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT | PMBUS_HAVE_IOUT |
> >     +         PMBUS_HAVE_IIN | PMBUS_HAVE_POUT | PMBUS_HAVE_PIN |
> >     +         PMBUS_HAVE_FAN12 | PMBUS_HAVE_TEMP | PMBUS_HAVE_TEMP2 |
> >     +         PMBUS_HAVE_TEMP3 | PMBUS_HAVE_STATUS_VOUT |
> >     +         PMBUS_HAVE_STATUS_IOUT | PMBUS_HAVE_STATUS_INPUT |
> >     +         PMBUS_HAVE_STATUS_TEMP | PMBUS_HAVE_STATUS_FAN12,
> > This can be dynamic read by chip identify function
>
> PMBUS_SKIP_STATUS_CHECK weakens auto-detetcion to some degree,
> and auto-detection takes time since it needs to poll all registers
> to determine if they exist. I don't mind if you insist, but I don't
> immediately see the benefits.

ipsps does not specify that the vendor must support the status_cml
register( some vendor do not support),
so PMBUS_SKIP_STATUS_CHECK is used here.

>
> >     + .groups = ipsps_groups,
> >     +};
> >     +
> >     +static struct pmbus_platform_data ipsps_pdata = {
> >     + .flags = PMBUS_SKIP_STATUS_CHECK,
> >     +};
> >     +
> >     +static int ipsps_probe(struct i2c_client *client,
> >     +                const struct i2c_device_id *id)
> >     +{
> >     + client->dev.platform_data = &ipsps_pdata;
> > Allocate memory for this platform data inside tis function rather than having global variable.
>
> Does that have any value other than consuming more memory
> if there are multiple instances of the driver ?
>
> >     + return pmbus_do_probe(client, id, &ipsps_info);
> >     +}
> >     +
> >     +static const struct i2c_device_id ipsps_id[] = {
> >     + { "inspur_ipsps1", 0 },
> >     + {}
> >     +};
> >     +MODULE_DEVICE_TABLE(i2c, ipsps_id);
> >     +
> >     +static const struct of_device_id ipsps_of_match[] = {
> >     + { .compatible = "inspur,ipsps1" },
> >     + {}
> >     +};
> >     +MODULE_DEVICE_TABLE(of, ipsps_of_match);
> >     +
> >     +static struct i2c_driver ipsps_driver = {
> >     + .driver = {
> >     +         .name = "inspur-ipsps",
> >     +         .of_match_table = ipsps_of_match,
> >     + },
> >     + .probe = ipsps_probe,
> >     + .remove = pmbus_do_remove,
> >     + .id_table = ipsps_id,
> >     +};
> >     +
> >     +module_i2c_driver(ipsps_driver);
> >     +
> >     +MODULE_AUTHOR("John Wang");
> >     +MODULE_DESCRIPTION("PMBus driver for Inspur Power System power supplies");
> >     +MODULE_LICENSE("GPL");
> >     --
> >     2.17.1
> >
> >
> >