Re: [PATCH 1/3] hwmon: (pmbus) Add driver for Delta DPS-920AB PSU

From: Robert Marko
Date: Thu May 27 2021 - 10:17:52 EST

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In reply to: Guenter Roeck: "Re: [PATCH 1/3] hwmon: (pmbus) Add driver for Delta DPS-920AB PSU"
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On Thu, May 27, 2021 at 4:03 PM Guenter Roeck <linux@xxxxxxxxxxxx> wrote:
>
> On 5/27/21 3:59 AM, Robert Marko wrote:
> > On Thu, May 27, 2021 at 12:22 PM Robert Marko <robert.marko@xxxxxxxxxx> wrote:
> >>
> >> On Mon, May 24, 2021 at 3:47 PM Guenter Roeck <linux@xxxxxxxxxxxx> wrote:
> >>>
> >>> On 5/24/21 5:21 AM, Robert Marko wrote:
> >>>> On Fri, May 21, 2021 at 4:46 PM Guenter Roeck <linux@xxxxxxxxxxxx> wrote:
> >>>>>
> >>>>> On 5/21/21 4:56 AM, Robert Marko wrote:
> >>>>>> On Fri, May 21, 2021 at 12:56 PM Guenter Roeck <linux@xxxxxxxxxxxx> wrote:
> >>>>>>>
> >>>>>>> On 5/21/21 1:36 AM, Robert Marko wrote:
> >>>>>>>> On Wed, May 19, 2021 at 3:19 PM Guenter Roeck <linux@xxxxxxxxxxxx> wrote:
> >>>>>>>>>
> >>>>>>>>> On 5/19/21 5:38 AM, Robert Marko wrote:
> >>>>>>>>>> On Fri, Apr 30, 2021 at 3:48 PM Guenter Roeck <linux@xxxxxxxxxxxx> wrote:
> >>>>>>>>>>>
> >>>>>>>>>>> On Fri, Apr 30, 2021 at 03:27:33PM +0200, Robert Marko wrote:
> >>>>>>>>>>>> This adds support for the Delta DPS-920AB PSU.
> >>>>>>>>>>>>
> >>>>>>>>>>>> Only missing feature is fan control which the PSU supports.
> >>>>>>>>>>>>
> >>>>>>>>>>>> Signed-off-by: Robert Marko <robert.marko@xxxxxxxxxx>
> >>>>>>>>>>>> ---
> >>>>>>>>>>>> Documentation/hwmon/dps920ab.rst | 80 ++++++++++++++++++++++++++++++++
> >>>>>>>>>>>> Documentation/hwmon/index.rst | 1 +
> >>>>>>>>>>>> drivers/hwmon/pmbus/Kconfig | 9 ++++
> >>>>>>>>>>>> drivers/hwmon/pmbus/Makefile | 1 +
> >>>>>>>>>>>> drivers/hwmon/pmbus/dps920ab.c | 63 +++++++++++++++++++++++++
> >>>>>>>>>>>> 5 files changed, 154 insertions(+)
> >>>>>>>>>>>> create mode 100644 Documentation/hwmon/dps920ab.rst
> >>>>>>>>>>>> create mode 100644 drivers/hwmon/pmbus/dps920ab.c
> >>>>>>>>>>>>
> >>>>>>>>>>>> diff --git a/Documentation/hwmon/dps920ab.rst b/Documentation/hwmon/dps920ab.rst
> >>>>>>>>>>>> new file mode 100644
> >>>>>>>>>>>> index 000000000000..df0aef530c7e
> >>>>>>>>>>>> --- /dev/null
> >>>>>>>>>>>> +++ b/Documentation/hwmon/dps920ab.rst
> >>>>>>>>>>>> @@ -0,0 +1,80 @@
> >>>>>>>>>>>> +.. SPDX-License-Identifier: GPL-2.0-or-later
> >>>>>>>>>>>> +
> >>>>>>>>>>>> +Kernel driver dps920ab
> >>>>>>>>>>>> +========================
> >>>>>>>>>>>> +
> >>>>>>>>>>>> +Supported chips:
> >>>>>>>>>>>> +
> >>>>>>>>>>>> + * Delta DPS920AB
> >>>>>>>>>>>> +
> >>>>>>>>>>>> + Prefix: 'dps920ab'
> >>>>>>>>>>>> +
> >>>>>>>>>>>> + Addresses scanned: -
> >>>>>>>>>>>> +
> >>>>>>>>>>>> +Authors:
> >>>>>>>>>>>> + Robert Marko <robert.marko@xxxxxxxxxx>
> >>>>>>>>>>>> +
> >>>>>>>>>>>> +
> >>>>>>>>>>>> +Description
> >>>>>>>>>>>> +-----------
> >>>>>>>>>>>> +
> >>>>>>>>>>>> +This driver implements support for Delta DPS920AB 920W 54V DC single output
> >>>>>>>>>>>> +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_crit Critical maximum current
> >>>>>>>>>>>> +curr1_crit_alarm Current critical high alarm
> >>>>>>>>>>>> +
> >>>>>>>>>>>> +curr2_label "iout1"
> >>>>>>>>>>>> +curr2_input Measured output current
> >>>>>>>>>>>> +curr2_crit Critical maximum current
> >>>>>>>>>>>> +curr2_crit_alarm Current critical high alarm
> >>>>>>>>>>>> +
> >>>>>>>>>>>> +in1_label "vin"
> >>>>>>>>>>>> +in1_input Measured input voltage
> >>>>>>>>>>>> +in1_lcrit Critical minimum input voltage
> >>>>>>>>>>>> +in1_lcrit_alarm Input voltage critical low alarm
> >>>>>>>>>>>> +in1_crit Critical maximum input voltage
> >>>>>>>>>>>> +in1_crit_alarm Input voltage critical high alarm
> >>>>>>>>>>>> +
> >>>>>>>>>>>> +in2_label "vout1"
> >>>>>>>>>>>> +in2_input Measured output voltage
> >>>>>>>>>>>> +in2_lcrit Critical minimum output voltage
> >>>>>>>>>>>> +in2_lcrit_alarm Output voltage critical low alarm
> >>>>>>>>>>>> +in2_crit Critical maximum output voltage
> >>>>>>>>>>>> +in2_crit_alarm Output voltage critical high alarm
> >>>>>>>>>>>> +
> >>>>>>>>>>>> +power1_label "pin"
> >>>>>>>>>>>> +power1_input Measured input power
> >>>>>>>>>>>> +power1_alarm Input power high alarm
> >>>>>>>>>>>> +
> >>>>>>>>>>>> +power2_label "pout1"
> >>>>>>>>>>>> +power2_input Measured output power
> >>>>>>>>>>>> +
> >>>>>>>>>>>> +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]_max Maximum temperature
> >>>>>>>>>>>> +temp[1-2]_max_alarm Chip temperature high alarm
> >>>>>>>>>>>> +
> >>>>>>>>>>>> +fan1_alarm Fan 1 warning.
> >>>>>>>>>>>> +fan1_fault Fan 1 fault.
> >>>>>>>>>>>> +fan1_input Fan 1 speed in RPM.
> >>>>>>>>>>>> +======================= ======================================================
> >>>>>>>>>>>> diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst
> >>>>>>>>>>>> index 8d5a2df1ecb6..b24436f22052 100644
> >>>>>>>>>>>> --- a/Documentation/hwmon/index.rst
> >>>>>>>>>>>> +++ b/Documentation/hwmon/index.rst
> >>>>>>>>>>>> @@ -54,6 +54,7 @@ Hardware Monitoring Kernel Drivers
> >>>>>>>>>>>> dell-smm-hwmon
> >>>>>>>>>>>> dme1737
> >>>>>>>>>>>> drivetemp
> >>>>>>>>>>>> + dps920ab
> >>>>>>>>>>>> ds1621
> >>>>>>>>>>>> ds620
> >>>>>>>>>>>> emc1403
> >>>>>>>>>>>> diff --git a/drivers/hwmon/pmbus/Kconfig b/drivers/hwmon/pmbus/Kconfig
> >>>>>>>>>>>> index 32d2fc850621..865ade0aa205 100644
> >>>>>>>>>>>> --- a/drivers/hwmon/pmbus/Kconfig
> >>>>>>>>>>>> +++ b/drivers/hwmon/pmbus/Kconfig
> >>>>>>>>>>>> @@ -66,6 +66,15 @@ config SENSORS_IBM_CFFPS
> >>>>>>>>>>>> This driver can also be built as a module. If so, the module will
> >>>>>>>>>>>> be called ibm-cffps.
> >>>>>>>>>>>>
> >>>>>>>>>>>> +config SENSORS_DPS920AB
> >>>>>>>>>>>> + tristate "Delta DPS920AB Power Supply"
> >>>>>>>>>>>> + help
> >>>>>>>>>>>> + If you say yes here you get hardware monitoring support for Delta
> >>>>>>>>>>>> + DPS920AB Power Supplies.
> >>>>>>>>>>>> +
> >>>>>>>>>>>> + This driver can also be built as a module. If so, the module will
> >>>>>>>>>>>> + be called dps920ab.
> >>>>>>>>>>>> +
> >>>>>>>>>>>> config SENSORS_INSPUR_IPSPS
> >>>>>>>>>>>> tristate "INSPUR Power System Power Supply"
> >>>>>>>>>>>> help
> >>>>>>>>>>>> diff --git a/drivers/hwmon/pmbus/Makefile b/drivers/hwmon/pmbus/Makefile
> >>>>>>>>>>>> index 6a4ba0fdc1db..f59ba0123d68 100644
> >>>>>>>>>>>> --- a/drivers/hwmon/pmbus/Makefile
> >>>>>>>>>>>> +++ b/drivers/hwmon/pmbus/Makefile
> >>>>>>>>>>>> @@ -9,6 +9,7 @@ obj-$(CONFIG_SENSORS_ADM1266) += adm1266.o
> >>>>>>>>>>>> obj-$(CONFIG_SENSORS_ADM1275) += adm1275.o
> >>>>>>>>>>>> obj-$(CONFIG_SENSORS_BEL_PFE) += bel-pfe.o
> >>>>>>>>>>>> obj-$(CONFIG_SENSORS_IBM_CFFPS) += ibm-cffps.o
> >>>>>>>>>>>> +obj-$(CONFIG_SENSORS_DPS920AB) += dps920ab.o
> >>>>>>>>>>>> obj-$(CONFIG_SENSORS_INSPUR_IPSPS) += inspur-ipsps.o
> >>>>>>>>>>>> obj-$(CONFIG_SENSORS_IR35221) += ir35221.o
> >>>>>>>>>>>> obj-$(CONFIG_SENSORS_IR38064) += ir38064.o
> >>>>>>>>>>>> diff --git a/drivers/hwmon/pmbus/dps920ab.c b/drivers/hwmon/pmbus/dps920ab.c
> >>>>>>>>>>>> new file mode 100644
> >>>>>>>>>>>> index 000000000000..d579ed9f879c
> >>>>>>>>>>>> --- /dev/null
> >>>>>>>>>>>> +++ b/drivers/hwmon/pmbus/dps920ab.c
> >>>>>>>>>>>> @@ -0,0 +1,63 @@
> >>>>>>>>>>>> +// SPDX-License-Identifier: GPL-2.0-or-later
> >>>>>>>>>>>> +/*
> >>>>>>>>>>>> + * Driver for Delta DPS920AB PSU
> >>>>>>>>>>>> + *
> >>>>>>>>>>>> + * Copyright (C) 2021 Delta Networks, Inc.
> >>>>>>>>>>>> + * Copyright (C) 2021 Sartura Ltd.
> >>>>>>>>>>>> + */
> >>>>>>>>>>>> +
> >>>>>>>>>>>> +#include <linux/i2c.h>
> >>>>>>>>>>>> +#include <linux/module.h>
> >>>>>>>>>>>> +#include <linux/of_device.h>
> >>>>>>>>>>>> +#include "pmbus.h"
> >>>>>>>>>>>> +
> >>>>>>>>>>>> +static struct pmbus_driver_info dps920ab_info = {
> >>>>>>>>>>>> + .pages = 1,
> >>>>>>>>>>>> +
> >>>>>>>>>>>> + .format[PSC_VOLTAGE_IN] = linear,
> >>>>>>>>>>>> + .format[PSC_VOLTAGE_OUT] = linear,
> >>>>>>>>>>>> + .format[PSC_CURRENT_IN] = linear,
> >>>>>>>>>>>> + .format[PSC_CURRENT_OUT] = linear,
> >>>>>>>>>>>> + .format[PSC_POWER] = linear,
> >>>>>>>>>>>> + .format[PSC_FAN] = linear,
> >>>>>>>>>>>> + .format[PSC_TEMPERATURE] = linear,
> >>>>>>>>>>>> +
> >>>>>>>>>>>> + .func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_IIN |
> >>>>>>>>>>>> + PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT |
> >>>>>>>>>>>> + PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT |
> >>>>>>>>>>>> + PMBUS_HAVE_TEMP | PMBUS_HAVE_TEMP2 |
> >>>>>>>>>>>> + PMBUS_HAVE_PIN | PMBUS_HAVE_POUT |
> >>>>>>>>>>>> + PMBUS_HAVE_FAN12 | PMBUS_HAVE_STATUS_FAN12 |
> >>>>>>>>>>>> + PMBUS_HAVE_STATUS_INPUT | PMBUS_HAVE_STATUS_TEMP,
> >>>>>>>>>>>> +};
> >>>>>>>>>>>> +
> >>>>>>>>>>>> +static int dps920ab_probe(struct i2c_client *client)
> >>>>>>>>>>>> +{
> >>>>>>>>>>>> + if (!i2c_check_functionality(client->adapter,
> >>>>>>>>>>>> + I2C_FUNC_SMBUS_BYTE_DATA |
> >>>>>>>>>>>> + I2C_FUNC_SMBUS_WORD_DATA))
> >>>>>>>>>>>> + return -ENODEV;
> >>>>>>>>>>>
> >>>>>>>>>>> This check is done in pmbus_do_probe(), and repeating it here does not add
> >>>>>>>>>>> any value.
> >>>>>>>>>>
> >>>>>>>>>> Ok, makes sense.
> >>>>>>>>>>>
> >>>>>>>>>>> That makes me wonder: Is this driver needed in the first place, or could
> >>>>>>>>>>> it be added to drivers/hwmon/pmbus/pmbus.c ?
> >>>>>>>>>>
> >>>>>>>>>> It could be added as a generic driver, but that creates properties in
> >>>>>>>>>> the sysfs that this thing
> >>>>>>>>>> does not support like 3 voltage readings, 3 fans, and so on.
> >>>>>>>>>>
> >>>>>>>>>
> >>>>>>>>> Can you be more specific ? What additional unsupported attributes
> >>>>>>>>> are added, and why ? Are you saying the PSU reports registers as
> >>>>>>>>> existing which do not really exist ? If so, which registers are those ?
> >>>>>>>>
> >>>>>>>> Sure, when core does probing and autodiscovery, then the following
> >>>>>>>> sysfs attributes are created:
> >>>>>>>>>
> >>>>>>>>> curr1_crit fan3_fault in3_min_alarm temp1_max
> >>>>>>>>> curr1_crit_alarm fan3_input in3_rated_max temp1_max_alarm
> >>>>>>>>> curr1_input fan3_target in3_rated_min temp1_min
> >>>>>>>>> curr1_label in1_crit name temp1_min_alarm
> >>>>>>>>> curr1_max in1_crit_alarm of_node temp1_rated_max
> >>>>>>>>> curr1_max_alarm in1_input power temp2_crit
> >>>>>>>>> curr1_rated_max in1_label power1_alarm temp2_crit_alarm
> >>>>>>>>> curr2_crit in1_lcrit power1_input temp2_input
> >>>>>>>>> curr2_crit_alarm in1_lcrit_alarm power1_label temp2_lcrit
> >>>>>>>>> curr2_input in1_max power1_max temp2_lcrit_alarm
> >>>>>>>>> curr2_label in1_max_alarm power1_rated_max temp2_max
> >>>>>>>>> curr2_lcrit in1_min power2_cap temp2_max_alarm
> >>>>>>>>> curr2_lcrit_alarm in1_min_alarm power2_cap_alarm temp2_min
> >>>>>>>>> curr2_max in1_rated_max power2_crit temp2_min_alarm
> >>>>>>>>> curr2_max_alarm in1_rated_min power2_crit_alarm temp2_rated_max
> >>>>>>>>> curr2_rated_max in2_input power2_input temp3_crit
> >>>>>>>>> device in2_label power2_label temp3_crit_alarm
> >>>>>>>>> fan1_alarm in3_crit power2_max temp3_input
> >>>>>>>>> fan1_fault in3_crit_alarm power2_max_alarm temp3_lcrit
> >>>>>>>>> fan1_input in3_input power2_rated_max temp3_lcrit_alarm
> >>>>>>>>> fan1_target in3_label subsystem temp3_max
> >>>>>>>>> fan2_alarm in3_lcrit temp1_crit temp3_max_alarm
> >>>>>>>>> fan2_fault in3_lcrit_alarm temp1_crit_alarm temp3_min
> >>>>>>>>> fan2_input in3_max temp1_input temp3_min_alarm
> >>>>>>>>> fan2_target in3_max_alarm temp1_lcrit temp3_rated_max
> >>>>>>>>> fan3_alarm in3_min temp1_lcrit_alarm uevent
> >>>>>>>>
> >>>>>>>> The following return -1, or -500 so they are not supported.
> >>>>>>>> * fan2
> >>>>>>>> * in2
> >>>>>>>>
> >>>>>>>> Weirdly, with the external driver both fan2 and in2 are enabled and work fine,
> >>>>>>>> but when auto probing they are fan3 and in3.
> >>>>>>>>
> >>>>>>>> temp3 actually seems to return a valid temperature despite it not being used in
> >>>>>>>> the vendor driver that features were picked from.
> >>>>>>>>
> >>>>>>>
> >>>>>>> Can you run "grep . *" in the hwmon directory so I can see actual values ?
> >>>>>>>
> >>>>>> Sure:
> >>>>>>>
> >>>>>>> curr1_crit:-500
> >>>>>>> curr1_crit_alarm:0
> >>>>>>> curr1_input:195
> >>>>>>> curr1_label:iin
> >>>>>>> curr1_max:-500
> >>>>>>> curr1_max_alarm:0
> >>>>>>> curr1_rated_max:-500
> >>>>>>> curr2_crit:-500
> >>>>>>> curr2_crit_alarm:0
> >>>>>>> curr2_input:320
> >>>>>>> curr2_label:iout1
> >>>>>>> curr2_lcrit:-500
> >>>>>>> curr2_lcrit_alarm:0
> >>>>>>> curr2_max:18625
> >>>>>>> curr2_max_alarm:0
> >>>>>>> curr2_rated_max:16875
> >>>>>>> grep: device: Is a directory
> >>>>>>> fan1_alarm:0
> >>>>>>> fan1_fault:0
> >>>>>>> fan1_input:10000
> >>>>>>> fan1_target:0
> >>>>>>> fan2_alarm:1
> >>>>>>> fan2_fault:1
> >>>>>>> fan2_input:-1
> >>>>>>> fan2_target:-1
> >>>>>>> fan3_alarm:1
> >>>>>>> fan3_fault:1
> >>>>>>> fan3_input:-1
> >>>>>>> fan3_target:-1
> >>>>>>> in1_crit:-500
> >>>>>>> in1_crit_alarm:0
> >>>>>>> in1_input:245250
> >>>>>>> in1_label:vin
> >>>>>>> in1_lcrit:-500
> >>>>>>> in1_lcrit_alarm:0
> >>>>>>> in1_max:-500
> >>>>>>> in1_max_alarm:0
> >>>>>>> in1_min:-500
> >>>>>>> in1_min_alarm:0
> >>>>>>> in1_rated_max:-500
> >>>>>>> in1_rated_min:-500
> >>>>>>> in2_input:-500
> >>>>>>> in2_label:vcap
> >>>>>>> in3_crit:255996
> >>>>>>> in3_crit_alarm:0
> >>>>>>> in3_input:54511
> >>>>>>> in3_label:vout1
> >>>>>>> in3_lcrit:255996
> >>>>>>> in3_lcrit_alarm:0
> >>>>>>> in3_max:255996
> >>>>>>> in3_max_alarm:0
> >>>>>>> in3_min:255996
> >>>>>>> in3_min_alarm:0
> >>>>>>> in3_rated_max:56136
> >>>>>>> in3_rated_min:52863
> >>>>>>> name:dps920ab
> >>>>>>> grep: of_node: Is a directory
> >>>>>>> grep: power: Is a directory
> >>>>>>> power1_alarm:0
> >>>>>>> power1_input:33250000
> >>>>>>> power1_label:pin
> >>>>>>> power1_max:-500000
> >>>>>>> power1_rated_max:-500000
> >>>>>>> power2_cap:-500000
> >>>>>>> power2_cap_alarm:0
> >>>>>>> power2_crit:-500000
> >>>>>>> power2_crit_alarm:0
> >>>>>>> power2_input:17750000
> >>>>>>> power2_label:pout1
> >>>>>>> power2_max:-500000
> >>>>>>> power2_max_alarm:0
> >>>>>>> power2_rated_max:920000000
> >>>>>>> grep: subsystem: Is a directory
> >>>>>>> temp1_crit:-500
> >>>>>>> temp1_crit_alarm:0
> >>>>>>> temp1_input:23000
> >>>>>>> temp1_lcrit:-500
> >>>>>>> temp1_lcrit_alarm:0
> >>>>>>> temp1_max:-500
> >>>>>>> temp1_max_alarm:0
> >>>>>>> temp1_min:-500
> >>>>>>> temp1_min_alarm:0
> >>>>>>> temp1_rated_max:-500
> >>>>>>> temp2_crit:-500
> >>>>>>> temp2_crit_alarm:0
> >>>>>>> temp2_input:26000
> >>>>>>> temp2_lcrit:-500
> >>>>>>> temp2_lcrit_alarm:0
> >>>>>>> temp2_max:-500
> >>>>>>> temp2_max_alarm:0
> >>>>>>> temp2_min:-500
> >>>>>>> temp2_min_alarm:0
> >>>>>>> temp2_rated_max:-500
> >>>>>>> temp3_crit:-500
> >>>>>>> temp3_crit_alarm:0
> >>>>>>> temp3_input:30000
> >>>>>>> temp3_lcrit:-500
> >>>>>>> temp3_lcrit_alarm:0
> >>>>>>> temp3_max:-500
> >>>>>>> temp3_max_alarm:0
> >>>>>>> temp3_min:-500
> >>>>>>> temp3_min_alarm:0
> >>>>>>> temp3_rated_max:-500
> >>>>>>> uevent:OF_NAME=psu
> >>>>>>> uevent:OF_FULLNAME=/ap806/config-space@f0000000/i2c@511000/psu@5a
> >>>>>>> uevent:OF_COMPATIBLE_0=delta,dps920ab
> >>>>>>> uevent:OF_COMPATIBLE_N=1
> >>>>>>
> >>>>> Ok, good enough. It looks like the PSU reports values for pretty much everything,
> >>>>> including registers which don't exist. With that in mind, please check
> >>>>> the attributes generated by your driver - I suspect that some of the limit
> >>>>> attributes are not really supported (maybe none of them is supported).
> >>>>
> >>>> Yeah, I also think that none of those limits are actually supported.
> >>>> Does the core expose a way to not register those?
> >>>>
> >>>
> >>> Have the read_word function return -ENXIO for unsupported registers
> >>> (and add a comment to the code explaining why you do that).
> >>> See drivers/hwmon/pmbus/fsp-3y.c for an example.
> >>
> >> Thanks, will implement that.
> >> In the meantime I finally got the PMBus command list that
> >> the PSU supports.
> >> It implements PMBus 1.2, but it also claims that MFR_ID,
> >> MFR_MODEL and MFR_REVISION are supported.
> >>
> >> Block read returns what looks like a correct length, but the buffer
> >> is empty.
> >>>
> >>> [ 195.246464] dps920ab 0-005a: PMBUS_MFR_ID length: 5
> >>> [ 195.251495] dps920ab 0-005a: PMBUS_MFR_ID:
> >>> [ 195.300789] dps920ab 0-005b: PMBUS_MFR_ID length: 5
> >>> [ 195.305762] dps920ab 0-005b: PMBUS_MFR_ID:
> >>> [ 272.795222] dps920ab 0-005a: PMBUS_MFR_ID length: 5
> >>> [ 272.800190] dps920ab 0-005a: PMBUS_MFR_ID:
> >>> [ 272.804862] dps920ab 0-005a: PMBUS_MFR_MODEL length: 11
> >>> [ 272.810172] dps920ab 0-005a: PMBUS_MFR_MODEL:
> >>> [ 272.815098] dps920ab 0-005a: PMBUS_MFR_REVISION length: 2
> >>> [ 272.820600] dps920ab 0-005a: PMBUS_MFR_REVISION:
> >>> [ 272.874060] dps920ab 0-005b: PMBUS_MFR_ID length: 5
> >>> [ 272.879102] dps920ab 0-005b: PMBUS_MFR_ID:
> >>> [ 272.883833] dps920ab 0-005b: PMBUS_MFR_MODEL length: 11
> >>> [ 272.889151] dps920ab 0-005b: PMBUS_MFR_MODEL:
> >>> [ 272.894097] dps920ab 0-005b: PMBUS_MFR_REVISION length: 2
> >>> [ 272.899548] dps920ab 0-005b: PMBUS_MFR_REVISION:
> >>
> >>
> >> However, manually reading using i2cget in word mode returns
> >> something that looks ok.
> >> i2cget -y 0 0x5a 0x9a w
> >> 0x440b
> >>
> >> This would be D is ASCII, it looks like any kind of block read fails actually.
> >
> > Ok, so after using i2c_smbus_read_i2c_block_data() I can actually read
> > the model kind of OK.
> > There actually are 10 bytes of valid data, no idea why
> > i2c_smbus_read_block_data() does not work.
> >>
> >> [ 721.194706] dps920ab 0-005a: MFR MODEL:
> >> DPS-920AB
> >> [ 721.245502] dps920ab 0-005b: MFR MODEL:
> >> DPS-920AB
> >
> > It behaves weirdly when printing by creating a newline before and
> > stuff like that.
> >
>
> I suspect it prints the first byte, which should be the length.
> I also suspect that the i2c controller driver has a bug and doesn't
> support SMBus block data correctly. Did you try i2cdump with i and s
> options ?

That could be the case, I just wanted to see whether the controller or
PSU are at fault.
I tried using s with i2cdump and it will error out on the controller
not supporting block reads.
The controller most likely has a bug in the driver.
>
> >> I tried applying the block support for mv64xx as well:
> >> https://patchwork.ozlabs.org/project/linux-i2c/patch/20200118115820.9080-1-fuga@xxxxxxxxxxxxxx/
>
> That patch would be needed, but it looks buggy to me. This chunk:
>
> + drv_data->effective_length = data+1;
> + drv_data->bytes_left = data+1;
> + drv_data->msg->len = data+1;
>
> should be:
>
> + drv_data->effective_length = data+1;
> + drv_data->bytes_left = data;
> + drv_data->msg->len = data+1;
>
> It should also make sure that 'data' is not larger than I2C_SMBUS_BLOCK_MAX,
> and bail out if it isn't.

Yeah, I did not check the contents, I just saw 2 reviews and tested it
since it can't hurt.
>
> Do you see a difference with the patch applied ?

No, unfortunately not, i2cdump in s mode returns all zeroes.
I can see that it gets the correct length but returns all zeroes.

I did some development on the driver, added whitelisting for
word-based registers.
Found that this thing actually has the third temperature sensor after
all and a lot of warnings
and stuff are supported.

I need to review the byte-based registers and whitelist those if needed.

Tried adding PWM/DC control for the fan as it supports it, but it was
a bit confusing so I
gave up on that for now.

Regards,
Robert
>
> Guenter

--
Robert Marko
Staff Embedded Linux Engineer
Sartura Ltd.
Lendavska ulica 16a
10000 Zagreb, Croatia
Email: robert.marko@xxxxxxxxxx
Web: www.sartura.hr

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