Re: [PATCH v2 2/4] hwmon: (pmbus/crps) Add Intel CRPS185 power supply

[Ninad Palsule <ninad@linux.ibm.com>]

Hi Guenter,

Thanks for the review.

On 12/16/24 12:26, Guenter Roeck wrote:
> On 12/16/24 09:50, Ninad Palsule wrote:
>> Add the driver to monitor Intel common redundant power supply (crps185)
>> with hwmon over pmbus.
>>
>> Signed-off-by: Ninad Palsule <ninad@linux.ibm.com>
>> ---
>>   Documentation/hwmon/crps.rst  | 97 +++++++++++++++++++++++++++++++++++
>>   Documentation/hwmon/index.rst |  1 +
>>   MAINTAINERS                   |  7 +++
>>   drivers/hwmon/pmbus/Kconfig   |  9 ++++
>>   drivers/hwmon/pmbus/Makefile  |  1 +
>>   drivers/hwmon/pmbus/crps.c    | 79 ++++++++++++++++++++++++++++
>>   6 files changed, 194 insertions(+)
>>   create mode 100644 Documentation/hwmon/crps.rst
>>   create mode 100644 drivers/hwmon/pmbus/crps.c
>>
>> diff --git a/Documentation/hwmon/crps.rst b/Documentation/hwmon/crps.rst
>> new file mode 100644
>> index 000000000000..74570ed1e978
>> --- /dev/null
>> +++ b/Documentation/hwmon/crps.rst
>> @@ -0,0 +1,97 @@
>> +.. SPDX-License-Identifier: GPL-2.0-or-later
>> +
>> +Kernel driver crps
>> +==================
>> +
>> +Supported chips:
>> +
>> +  * Intel CRPS185
>> +
>> +    Prefix: 'crps185'
>> +
>> +    Addresses scanned: -
>> +
>> +    Datasheet: Publicly not available.
>
> Maybe "Only available under NDA". Or at least that is what I found.
Updated as per your suggestion.
>
>> +
>> +Authors:
>> +    Ninad Palsule <ninad@linux.ibm.com>
>> +
>> +
>> +Description
>> +-----------
>> +
>> +This driver implements support for Intel Common Redundant Power 
>> supply with
>> +PMBus support.
>> +
>> +The driver is a client driver to the core PMBus driver.
>> +Please see Documentation/hwmon/pmbus.rst for details on PMBus client 
>> drivers.
>> +
>> +
>> +Usage Notes
>> +-----------
>> +
>> +This driver does not auto-detect devices. You will have to 
>> instantiate the
>> +devices explicitly. Please see 
>> Documentation/i2c/instantiating-devices.rst for
>> +details.
>> +
>> +
>> +Sysfs entries
>> +-------------
>> +
>> +======================= 
>> ======================================================
>> +curr1_label        "iin"
>> +curr1_input        Measured input current
>> +curr1_max        Maximum input current
>> +curr1_max_alarm         Input maximum current high alarm
>> +curr1_crit              Critial high input current
>> +curr1_crit_alarm        Input critical current high alarm
>> +curr1_rated_max        Maximum rated input current
>> +
>> +curr2_label        "iout1"
>> +curr2_input        Measured output current
>> +curr2_max        Maximum output current
>> +curr2_max_alarm         Output maximum current high alarm
>> +curr2_crit            Critial high output current
>> +curr2_crit_alarm        Output critical current high alarm
>> +curr2_rated_max        Maximum rated output current
>> +
>> +in1_label        "vin"
>> +in1_input        Measured input voltage
>> +in1_crit                Critical input over voltage
>> +in1_crit_alarm          Critical input over voltage alarm
>> +in1_max                 Maximum input over voltage
>> +in1_max_alarm           Maximum input over voltage alarm
>> +in1_rated_min        Minimum rated input voltage
>> +in1_rated_max        Maximum rated input voltage
>> +
>> +in2_label        "vout1"
>> +in2_input        Measured input voltage
>> +in2_crit                Critical input over voltage
>> +in2_crit_alarm          Critical input over voltage alarm
>> +in2_lcrit               Critical input under voltage fault
>> +in2_lcrit_alarm         Critical input under voltage fault alarm
>> +in2_max                 Maximum input over voltage
>> +in2_max_alarm           Maximum input over voltage alarm
>> +in2_min                 Minimum input under voltage warning
>> +in2_min_alarm           Minimum input under voltage warning alarm
>> +in2_rated_min        Minimum rated input voltage
>> +in2_rated_max        Maximum rated input voltage
>> +
>> +power1_label        "pin"
>> +power1_input        Measured input power
>> +power1_alarm        Input power high alarm
>> +power1_max          Maximum input power
>> +power1_rated_max        Maximum rated input power
>> +
>> +temp[1-2]_input        Measured temperature
>> +temp[1-2]_crit         Critical temperature
>> +temp[1-2]_crit_alarm    Critical temperature alarm
>> +temp[1-2]_max          Maximum temperature
>> +temp[1-2]_max_alarm     Maximum temperature alarm
>> +temp[1-2]_rated_max     Maximum rated temperature
>> +
>> +fan1_alarm        Fan 1 warning.
>> +fan1_fault        Fan 1 fault.
>> +fan1_input        Fan 1 speed in RPM.
>> +fan1_target             Fan 1 target.
>> +======================= 
>> ======================================================
>
> Does this pass "make htmldocs" ?

Yes, I don't get any error. I run following command on the top level 
directory.

export ARCH=arm;export CROSS_COMPILE="arm-linux-gnueabi-";make htmldocs

>
>
>> diff --git a/Documentation/hwmon/index.rst 
>> b/Documentation/hwmon/index.rst
>> index 1a3cb0a59f72..b1ea445479b0 100644
>> --- a/Documentation/hwmon/index.rst
>> +++ b/Documentation/hwmon/index.rst
>> @@ -58,6 +58,7 @@ Hardware Monitoring Kernel Drivers
>>      corsair-cpro
>>      corsair-psu
>>      cros_ec_hwmon
>> +   crps
>>      da9052
>>      da9055
>>      dell-smm-hwmon
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index 637ddd44245f..e99f26f75733 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -6100,6 +6100,13 @@ L:    linux-input@vger.kernel.org
>>   S:    Maintained
>>   F:    drivers/hid/hid-creative-sb0540.c
>>   +INTEL CRPS COMMON REDUNDANT PSU DRIVER
>> +M:    Ninad Palsule <ninad@linux.ibm.com>
>> +L:    linux-hwmon@vger.kernel.org
>> +S:    Maintained
>> +F:    Documentation/hwmon/crps.rst
>> +F:    drivers/hwmon/pmbus/crps.c
>> +
>>   CRYPTO API
>>   M:    Herbert Xu <herbert@gondor.apana.org.au>
>>   M:    "David S. Miller" <davem@davemloft.net>
>> diff --git a/drivers/hwmon/pmbus/Kconfig b/drivers/hwmon/pmbus/Kconfig
>> index 22418a05ced0..43b6df04e0f9 100644
>> --- a/drivers/hwmon/pmbus/Kconfig
>> +++ b/drivers/hwmon/pmbus/Kconfig
>> @@ -85,6 +85,15 @@ config SENSORS_BPA_RS600
>>         This driver can also be built as a module. If so, the module 
>> will
>>         be called bpa-rs600.
>>   +config SENSORS_CRPS
>> +    tristate "Intel Common Redundant Power Supply"
>> +    help
>> +      If you say yes here you get hardware monitoring support for 
>> the Intel
>> +      Common Redundant Power Supply.
>> +
>> +      This driver can also be built as a module. If so, the module will
>> +      be called crps.
>> +
>>   config SENSORS_DELTA_AHE50DC_FAN
>>       tristate "Delta AHE-50DC fan control module"
>>       help
>> diff --git a/drivers/hwmon/pmbus/Makefile b/drivers/hwmon/pmbus/Makefile
>> index 3d3183f8d2a7..c7eb7739b7f8 100644
>> --- a/drivers/hwmon/pmbus/Makefile
>> +++ b/drivers/hwmon/pmbus/Makefile
>> @@ -62,3 +62,4 @@ obj-$(CONFIG_SENSORS_XDPE122)    += xdpe12284.o
>>   obj-$(CONFIG_SENSORS_XDPE152)    += xdpe152c4.o
>>   obj-$(CONFIG_SENSORS_ZL6100)    += zl6100.o
>>   obj-$(CONFIG_SENSORS_PIM4328)    += pim4328.o
>> +obj-$(CONFIG_SENSORS_CRPS)    += crps.o
>> diff --git a/drivers/hwmon/pmbus/crps.c b/drivers/hwmon/pmbus/crps.c
>> new file mode 100644
>> index 000000000000..09425c404fc8
>> --- /dev/null
>> +++ b/drivers/hwmon/pmbus/crps.c
>> @@ -0,0 +1,79 @@
>> +// SPDX-License-Identifier: GPL-2.0-or-later
>> +/*
>> + * Copyright 2024 IBM Corp.
>> + */
>> +
>> +#include <linux/i2c.h>
>> +#include <linux/of.h>
>> +#include <linux/pmbus.h>
>> +
>> +#include "pmbus.h"
>> +
>> +static const struct i2c_device_id crps_id[] = {
>> +    { "intel_crps185" },
>> +    {}
>> +};
>> +MODULE_DEVICE_TABLE(i2c, crps_id);
>> +
>> +static struct pmbus_driver_info crps_info = {
>> +    .pages = 1,
>> +    /* PSU uses default linear data format. */
>> +    .func[0] = PMBUS_HAVE_PIN | PMBUS_HAVE_IOUT |
>> +        PMBUS_HAVE_STATUS_IOUT | PMBUS_HAVE_IIN |
>> +        PMBUS_HAVE_VIN | PMBUS_HAVE_STATUS_INPUT |
>> +        PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT |
>> +        PMBUS_HAVE_TEMP | PMBUS_HAVE_TEMP2 |
>> +        PMBUS_HAVE_STATUS_TEMP |
>> +        PMBUS_HAVE_FAN12 | PMBUS_HAVE_STATUS_FAN12,
>> +};
>> +
>> +static int crps_probe(struct i2c_client *client)
>> +{
>> +    int rc;
>> +    struct device *dev = &client->dev;
>> +    char buf[I2C_SMBUS_BLOCK_MAX + 2] = { 0 };
>> +
>> +    rc = i2c_smbus_read_block_data(client, PMBUS_MFR_MODEL, buf);
>> +    if (rc < 0) {
>> +        dev_err_probe(dev, rc, "Failed to read PMBUS_MFR_MODEL\n");
>> +        return rc;
>
>         return dev_err_probe(...);
>
>> +    }
>> +
>> +    if (strncmp(buf, "03NK260", 7) == 7) {
>
> strncmp() never returns 7. You probably want something like
>
>     if (rc != 7 || strncmp(buf, "03NK260", 7)) {
My bad. Fixed it.
>
>> +        buf[rc] = '\0';
>> +        dev_err_probe(dev, -ENODEV, "Model '%s' not supported\n", buf);
>
>         return dev_err_probe(...);
Fixed.
>
>> +        return -ENODEV;
>> +    }
>> +
>> +    rc = pmbus_do_probe(client, &crps_info);
>> +    if (rc) {
>> +        dev_err_probe(dev, rc, "Failed to probe %d\n", rc);
>
> dev_err_probe() already handles the error, and a message such as
> "failed to probe -22" isn't very useful anyway. Also,
>         return dev_err_probe(...);
Fixed.


Thanks and regards,

Ninad Palsule