[AST2600] PWM/TACH driver and dbus-sensor issue

Tung Nguyen OS tungnguyen at os.amperecomputing.com
Tue Feb 15 21:10:10 AEDT 2022


Hi Billy,

Please help check:
root at sunmoonlake:/tmp# ./test.sh 100
echo 100 > /sys/class/hwmon/hwmon1/pwm1
cat /sys/class/hwmon/hwmon0/fan1_input
0
devmem 0x1e610000
0x0001101E
devmem 0x1e610004
0xFF006500
devmem 0x1e610008
0x10500000
devmem 0x1e61000c
0xA5400000
root at sunmoonlake:/tmp# ./test.sh 120
echo 120 > /sys/class/hwmon/hwmon1/pwm1
cat /sys/class/hwmon/hwmon0/fan1_input
266335
devmem 0x1e610000
0x0001101E
devmem 0x1e610004
0xFF007900
devmem 0x1e610008
0x10500000
devmem 0x1e61000c
0xF4B00016
root at sunmoonlake:/tmp# ./test.sh 140
echo 140 > /sys/class/hwmon/hwmon1/pwm1
cat /sys/class/hwmon/hwmon0/fan1_input
837053
devmem 0x1e610000
0x0001101E
devmem 0x1e610004
0xFF008D00
devmem 0x1e610008
0x10500000
devmem 0x1e61000c
0xE4B00007
root at sunmoonlake:/tmp# ./test.sh 255
echo 255 > /sys/class/hwmon/hwmon1/pwm1
cat /sys/class/hwmon/hwmon0/fan1_input
0
devmem 0x1e610000
0x0001101E
devmem 0x1e610004
0xFF000000
devmem 0x1e610008
0x10500000
devmem 0x1e61000c
0xB5C00000
root at sunmoonlake:/tmp#

Please note that i'm using the fan settings as:

        fan0: pwm-fan0 {
                compatible = "pwm-fan";
                pwms = <&pwm 0 40000 0>;        /* Target freq:25 kHz */
                cooling-min-state = <0>;
                cooling-max-state = <3>;
                #cooling-cells = <2>;
                cooling-levels = <0 25 128 255>;
        };
.....
        fan at 0 {
                reg = <0x00>;
                aspeed,pulse-pr = <2>;
        };


________________________________________
From: Billy Tsai <billy_tsai at aspeedtech.com>
Sent: Monday, February 14, 2022 1:34 PM
To: Tung Nguyen OS; Troy Lee; openbmc at lists.ozlabs.org
Cc: Thu Nguyen OS; Thang Nguyen OS; Phong Vo OS
Subject: Re: [AST2600] PWM/TACH driver and dbus-sensor issue

Hi Tung,

Can you check the PWM frequency and dump the register value 0x1e610000~0x1e61000c?

Thanks

Best Regards,
Billy Tsai

From: Tung Nguyen OS <tungnguyen at os.amperecomputing.com>
Date: Monday, February 14, 2022 at 12:24 PM
To: Troy Lee <troy_lee at aspeedtech.com>, "openbmc at lists.ozlabs.org" <openbmc at lists.ozlabs.org>
Cc: Thu Nguyen OS <thu at os.amperecomputing.com>, Thang Nguyen OS <thang at os.amperecomputing.com>, Phong Vo OS <phong at os.amperecomputing.com>, Billy Tsai <billy_tsai at aspeedtech.com>
Subject: Re: [AST2600] PWM/TACH driver and dbus-sensor issue

Hi Troy,
the fan settings in device tree are similar to aspeed-ast2600a1-evb.dts, like:

        fan0: pwm-fan0 {
                compatible = "pwm-fan";
                pwms = <&pwm 0 40000 0>;        /* Target freq:25 kHz */
                cooling-min-state = <0>;
                cooling-max-state = <3>;
                #cooling-cells = <2>;
                cooling-levels = <0 25 128 255>;
        };
.....
        fan at 0 {
                reg = <0x00>;
                aspeed,pulse-pr = <2>;
        };

I test with co-fan F-5010HH12B and San Ace 92 with above setting, and the result looks like in-correct as in previous email.

________________________________________
From: Troy Lee <troy_lee at aspeedtech.com<mailto:troy_lee at aspeedtech.com>>
Sent: Monday, February 14, 2022 11:02 AM
To: Tung Nguyen OS; openbmc at lists.ozlabs.org<mailto:openbmc at lists.ozlabs.org>
Cc: Thu Nguyen OS; Thang Nguyen OS; Phong Vo OS; Billy Tsai
Subject: RE: [AST2600] PWM/TACH driver and dbus-sensor issue

Adding Billy.

Hi Tung,

-----Original Message-----
From: Tung Nguyen OS <tungnguyen at os.amperecomputing.com<mailto:tungnguyen at os.amperecomputing.com>>
Sent: Monday, February 14, 2022 11:46 AM
To: Troy Lee <troy_lee at aspeedtech.com<mailto:troy_lee at aspeedtech.com>>; openbmc at lists.ozlabs.org<mailto:openbmc at lists.ozlabs.org>
Cc: Thu Nguyen OS <thu at os.amperecomputing.com<mailto:thu at os.amperecomputing.com>>; Thang Nguyen OS
<thang at os.amperecomputing.com<mailto:thang at os.amperecomputing.com>>; Phong Vo OS
<phong at os.amperecomputing.com<mailto:phong at os.amperecomputing.com>>
Subject: Re: [AST2600] PWM/TACH driver and dbus-sensor issue

Hi Troy,
Thank you for the information, i have merged the dbus-sensor patch and see
it creates the Fan sensors well.
One more issue i have observed about the fan tach report like this:

root at mtmitchell:~# echo 120 > /sys/class/hwmon/hwmon1/pwm1
root at mtmitchell:~# cat /sys/class/hwmon/hwmon0/fan1_input
418526
root at mtmitchell:~# echo 100 > /sys/class/hwmon/hwmon1/pwm1
root at mtmitchell:~# cat /sys/class/hwmon/hwmon0/fan1_input
195312
root at mtmitchell:~# echo 255 > /sys/class/hwmon/hwmon1/pwm1
root at mtmitchell:~# cat /sys/class/hwmon/hwmon0/fan1_input
0
root at mtmitchell:~# echo 50 > /sys/class/hwmon/hwmon1/pwm1
root at mtmitchell:~# cat /sys/class/hwmon/hwmon0/fan1_input
0

It means the fan speed is reported incorrectly somehow, but i can see the
fan speed changes by eyes, do you have idea on this issue ?

Does the aspeed,pulse-pr property of fan node set correspondingly?
What is the expected RPM of you fan? 418526 RPM?

Thanks,
Troy Lee


________________________________________
From: Troy Lee <troy_lee at aspeedtech.com<mailto:troy_lee at aspeedtech.com>>
Sent: Friday, February 11, 2022 12:13 PM
To: Tung Nguyen OS; openbmc at lists.ozlabs.org<mailto:openbmc at lists.ozlabs.org>
Cc: Thu Nguyen OS; Thang Nguyen OS; Phong Vo OS
Subject: RE: [AST2600] PWM/TACH driver and dbus-sensor issue

Hi Tung,

> -----Original Message-----
> From: openbmc <openbmc-
> bounces+troy_lee=aspeedtech.com at lists.ozlabs.org<mailto:aspeedtech.com at lists.ozlabs.org>> On Behalf Of Tung
> Nguyen OS
> Sent: Wednesday, February 9, 2022 10:40 PM
> To: openbmc at lists.ozlabs.org<mailto:openbmc at lists.ozlabs.org>
> Cc: Thu Nguyen OS <thu at os.amperecomputing.com<mailto:thu at os.amperecomputing.com>>; Thang Nguyen OS
> <thang at os.amperecomputing.com<mailto:thang at os.amperecomputing.com>>; Phong Vo OS
> <phong at os.amperecomputing.com<mailto:phong at os.amperecomputing.com>>
> Subject: [AST2600] PWM/TACH driver and dbus-sensor issue
>
> Dear community,
> We have ported the PWM/TACH hwmon driver for AST2600 from ASPEED's
> repository https://github.com/AspeedTech-BMC/linux/tree/aspeed-
master-
> v5.4/drivers/hwmon to support Ampere Computing's systems. Verify with
> AST2600 EVB, i can see the driver works. However there is a concern like:
> 1. The change of hwmon fan pwm/tach in sysfs (as below), this is
> different from the ast2500 as the separated of the fan*_input and pwm1
> in various hwmon directories. At this time, the driver doesn't exist
> in the OpenBMC linux at https://github.com/openbmc/linux. Is OpenBMC
> going to merge and keep this driver ?

Please have a look on this patch.
https://gerrit.openbmc-project.xyz/c/openbmc/dbus-sensors/+/49253

Thanks,
Troy Lee

> root at mtmitchell:~# ls -la /sys/class/hwmon/hwmon hwmon0/ hwmon1/
> hwmon2/ hwmon3/ hwmon4/ hwmon5/ hwmon6/ hwmon7/ hwmon8/
hwmon9/
> root at mtmitchell:~# ls -la /sys/class/hwmon/hwmon0/
> drwxr-xr-x    3 root     root             0 Jan  1  1970 .
> drwxr-xr-x    3 root     root             0 Jan  1  1970 ..
> lrwxrwxrwx    1 root     root             0 Feb  9 08:38 device -
> > ../../../1e610000.pwm_tach:tach
> -r--r--r--    1 root     root          4096 Feb  9 08:38 fan10_input
> -r--r--r--    1 root     root          4096 Feb  9 08:38 fan11_input
> -r--r--r--    1 root     root          4096 Feb  9 08:38 fan12_input
> -r--r--r--    1 root     root          4096 Feb  9 08:38 fan13_input
> -r--r--r--    1 root     root          4096 Feb  9 08:38 fan14_input
> -r--r--r--    1 root     root          4096 Feb  9 08:38 fan15_input
> -r--r--r--    1 root     root          4096 Feb  9 08:38 fan16_input
> -r--r--r--    1 root     root          4096 Feb  9 08:38 fan1_input
> -r--r--r--    1 root     root          4096 Feb  9 08:38 fan2_input
> -r--r--r--    1 root     root          4096 Feb  9 08:38 fan3_input
> -r--r--r--    1 root     root          4096 Feb  9 08:38 fan4_input
> -r--r--r--    1 root     root          4096 Feb  9 08:38 fan5_input
> -r--r--r--    1 root     root          4096 Feb  9 08:38 fan6_input
> -r--r--r--    1 root     root          4096 Feb  9 08:38 fan7_input
> -r--r--r--    1 root     root          4096 Feb  9 08:38 fan8_input
> -r--r--r--    1 root     root          4096 Feb  9 08:38 fan9_input
> -r--r--r--    1 root     root          4096 Feb  9 08:38 name
> lrwxrwxrwx    1 root     root             0 Feb  9 08:38 of_node -
> > ../../../../../../../../firmware/devicetree/base/ahb/apb/pwm_tach at 1e
> > 610
> 000/tach
> drwxr-xr-x    2 root     root             0 Feb  9 08:38 power
> lrwxrwxrwx    1 root     root             0 Jan  1  1970 subsystem -
> > ../../../../../../../../class/hwmon
> -rw-r--r--    1 root     root          4096 Jan  1  1970 uevent
> root at mtmitchell:~# ls -la /sys/class/hwmon/hwmon*/pwm*
> -rw-r--r--    1 root     root          4096 Feb  9 09:13
> /sys/class/hwmon/hwmon1/pwm1
> -rw-r--r--    1 root     root          4096 Feb  9 09:20
> /sys/class/hwmon/hwmon2/pwm1
> -rw-r--r--    1 root     root          4096 Feb  9 08:38
> /sys/class/hwmon/hwmon3/pwm1
> -rw-r--r--    1 root     root          4096 Feb  9 08:38
> /sys/class/hwmon/hwmon4/pwm1
> -rw-r--r--    1 root     root          4096 Feb  9 08:38
> /sys/class/hwmon/hwmon5/pwm1
> -rw-r--r--    1 root     root          4096 Feb  9 08:38
> /sys/class/hwmon/hwmon6/pwm1
> -rw-r--r--    1 root     root          4096 Feb  9 08:38
> /sys/class/hwmon/hwmon7/pwm1
> -rw-r--r--    1 root     root          4096 Feb  9 08:38
> /sys/class/hwmon/hwmon8/pwm1
>
> 2. With above changes, the dbus-sensor for FAN/PWM shall not work
> because of the compatibility. So if OpenBMC want to keep above
> PWM/TACH driver, does any sides have the plan to support the fan
> sensor, if not, we can join and do it.
>
> Thank you and best regards,
> Tung



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