Messages in this thread Patch in this message | | | Date | Tue, 7 Dec 2021 13:53:39 -0800 | From | Zev Weiss <> | Subject | Re: [PATCH v3 1/2] hwmon: (pmbus) Add Delta AHE-50DC fan control module driver |
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On Tue, Dec 07, 2021 at 11:44:01AM PST, Guenter Roeck wrote: >On 12/7/21 11:22 AM, Zev Weiss wrote: >>On Tue, Dec 07, 2021 at 09:50:15AM PST, Guenter Roeck wrote: >>>On Mon, Dec 06, 2021 at 11:15:20PM -0800, Zev Weiss wrote: >>>>This device is an integrated module of the Delta AHE-50DC Open19 power >>>>shelf. For lack of proper documentation, this driver has been developed >>>>referencing an existing (GPL) driver that was included in a code release >>>>from LinkedIn [1]. It provides four fan speeds, four temperatures, and >>>>one voltage reading, as well as a handful of warning and fault >>>>indicators. >>>> >>>>[1] https://github.com/linkedin/o19-bmc-firmware/blob/master/meta-openbmc/meta-linkedin/meta-deltapower/recipes-kernel/fancontrol-mod/files/fancontrol.c >>>> >>> >>>Hmm, that reference isn't really accurate anymore. I think it would be >>>better to just say that the device was found to be PMBus compliant. >> >>Sure, will do. >> > > Makes me wonder: How do you know that the referenced driver is for > Delta AHE-50DC ?
We'd been waiting for the source code for the software it ships with for a while, and were finally provided with that repo; everything I've observed from the factory software is consistent with the code in that driver. A sampling:
# no modinfo command available, but... root@bmc-oob:~# strings -n8 /lib/modules/4.1.51-deltapower/extra/fancontrol.ko | head fancontrol license=GPL description=FANCTRL Driver author=Ping Mao <pmao@linkedin.com> alias=i2c:fancontrol depends=i2c_dev_sysfs vermagic=4.1.51-deltapower mod_unload ARMv5 p2v8 fancontrol status_word bit 2: Temparature Warning root@bmc-oob:~# cd /sys/bus/i2c/drivers/fancontrol/8-0030 root@bmc-oob:/sys/bus/i2c/drivers/fancontrol/8-0030# grep . fan* temp* vin fan1_2_status:0 fan1_speed:7860 fan2_speed:7860 fan3_4_status:0 fan3_speed:7680 fan4_speed:7560 temperature1:292 temperature2:278 temperature3:286 temperature4:302 vin:12251
>>> >>>>Signed-off-by: Zev Weiss <zev@bewilderbeest.net> >>>>--- >>>> MAINTAINERS | 6 ++ >>>> drivers/hwmon/pmbus/Kconfig | 12 ++++ >>>> drivers/hwmon/pmbus/Makefile | 1 + >>>> drivers/hwmon/pmbus/delta-ahe50dc-fan.c | 84 +++++++++++++++++++++++++ >>>> 4 files changed, 103 insertions(+) >>>> create mode 100644 drivers/hwmon/pmbus/delta-ahe50dc-fan.c >>>> >>>>diff --git a/MAINTAINERS b/MAINTAINERS >>>>index 0ac052200ecb..8bb7ba52d2f5 100644 >>>>--- a/MAINTAINERS >>>>+++ b/MAINTAINERS >>>>@@ -5425,6 +5425,12 @@ W: https://linuxtv.org >>>> T: git git://linuxtv.org/media_tree.git >>>> F: drivers/media/platform/sti/delta >>>> >>>>+DELTA AHE-50DC FAN CONTROL MODULE DRIVER >>>>+M: Zev Weiss <zev@bewilderbeest.net> >>>>+L: linux-hwmon@vger.kernel.org >>>>+S: Maintained >>>>+F: drivers/hwmon/pmbus/delta-ahe50dc-fan.c >>>>+ >>>> DELTA DPS920AB PSU DRIVER >>>> M: Robert Marko <robert.marko@sartura.hr> >>>> L: linux-hwmon@vger.kernel.org >>>>diff --git a/drivers/hwmon/pmbus/Kconfig b/drivers/hwmon/pmbus/Kconfig >>>>index ffb609cee3a4..937e1c2c11e7 100644 >>>>--- a/drivers/hwmon/pmbus/Kconfig >>>>+++ b/drivers/hwmon/pmbus/Kconfig >>>>@@ -66,6 +66,18 @@ config SENSORS_BPA_RS600 >>>> This driver can also be built as a module. If so, the module will >>>> be called bpa-rs600. >>>> >>>>+config SENSORS_DELTA_AHE50DC_FAN >>>>+ tristate "Delta AHE-50DC fan control module" >>>>+ depends on I2C >>>>+ select REGMAP_I2C >> >>And I realize I neglected to drop the depends & select lines here when moving this bit into the pmbus directory... >> >>>>+ help >>>>+ If you say yes here you get hardware monitoring support for >>>>+ the integrated fan control module of the Delta AHE-50DC >>>>+ Open19 power shelf. >>>>+ >>>>+ This driver can also be built as a module. If so, the module >>>>+ will be called delta-ahe50dc-fan. >>>>+ >>>> config SENSORS_FSP_3Y >>>> tristate "FSP/3Y-Power power supplies" >>>> help >>>>diff --git a/drivers/hwmon/pmbus/Makefile b/drivers/hwmon/pmbus/Makefile >>>>index 0ed4d596a948..a56b2897288d 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_BPA_RS600) += bpa-rs600.o >>>>+obj-$(CONFIG_SENSORS_DELTA_AHE50DC_FAN) += delta-ahe50dc-fan.o >>>> obj-$(CONFIG_SENSORS_FSP_3Y) += fsp-3y.o >>>> obj-$(CONFIG_SENSORS_IBM_CFFPS) += ibm-cffps.o >>>> obj-$(CONFIG_SENSORS_DPS920AB) += dps920ab.o >>>>diff --git a/drivers/hwmon/pmbus/delta-ahe50dc-fan.c b/drivers/hwmon/pmbus/delta-ahe50dc-fan.c >>>>new file mode 100644 >>>>index 000000000000..07b1e7c5f5f5 >>>>--- /dev/null >>>>+++ b/drivers/hwmon/pmbus/delta-ahe50dc-fan.c >>>>@@ -0,0 +1,84 @@ >>>>+// SPDX-License-Identifier: GPL-2.0 >>>>+/* >>>>+ * Delta AHE-50DC power shelf fan control module driver >>>>+ * >>>>+ * Copyright 2021 Zev Weiss <zev@bewilderbeest.net> >>>>+ */ >>>>+ >>>>+#include <linux/kernel.h> >>>>+#include <linux/module.h> >>>>+#include <linux/i2c.h> >>>>+#include <linux/pmbus.h> >>>Alphabetic include file order please. >> >>Ack, will fix. >> >>> >>>>+ >>>>+#include "pmbus.h" >>>>+ >>>>+#define AHE50DC_PMBUS_READ_TEMP4 0xd0 >>>>+ >>>>+static int ahe50dc_fan_read_word_data(struct i2c_client *client, int page, int phase, int reg) >>>>+{ >>>>+ /* temp1 in (virtual) page 1 is remapped to mfr-specific temp4 */ >>>>+ if (page == 1) { >>>>+ if (reg == PMBUS_READ_TEMPERATURE_1) >>>>+ return i2c_smbus_read_word_data(client, AHE50DC_PMBUS_READ_TEMP4); >>>>+ return -EOPNOTSUPP; >>>>+ } >>>>+ return -ENODATA; >>>>+} >>>>+ >>>>+static struct pmbus_driver_info ahe50dc_fan_info = { >>>>+ .pages = 2, >>>>+ .format[PSC_FAN] = direct, >>>>+ .format[PSC_TEMPERATURE] = direct, >>>>+ .format[PSC_VOLTAGE_IN] = direct, >>>>+ .m[PSC_FAN] = 1, >>>>+ .b[PSC_FAN] = 0, >>>>+ .R[PSC_FAN] = 0, >>>>+ .m[PSC_TEMPERATURE] = 1, >>>>+ .b[PSC_TEMPERATURE] = 0, >>>>+ .R[PSC_TEMPERATURE] = 1, >>>>+ .m[PSC_VOLTAGE_IN] = 1, >>>>+ .b[PSC_VOLTAGE_IN] = 0, >>>>+ .R[PSC_VOLTAGE_IN] = 3, >>> >>>How did you determine the exponents ? The referenced driver >>>doesn't seem to make a difference between voltage and temperature >>>exponents (nor fan speed, which is a bit odd). >> >>Lacking documentation, the honest answer here is that I just sort of eyeballed it. However, after doing so, I dug through the code dump a bit more and found some userspace unit-conversion bits that appear to confirm what I arrived at: >> >>https://github.com/linkedin/o19-bmc-firmware/blob/master/meta-openbmc/meta-linkedin/meta-deltapower/recipes-deltapower/platform-lib/files/powershelf/powershelf_fan.c >> >>(Lines 107, and 153/161/169/177.) >> > >Brr. Well, why use a standard API/ABI if one can invent a non-standard one. >
It's...not the only bit of gratuitous wheel-reinvention we've come across in this particular system.
>Can you check this with real hardware, by any chance ? >
If you mean running that code on it, yes -- here's the userspace utility that invokes that library routine:
root@bmc-oob:~# fan-util.sh fan1 speed: 7860 RPM fan2 speed: 7860 RPM fan3 speed: 7620 RPM fan4 speed: 7560 RPM temperature1: 29.20 C temperature2: 27.80 C temperature3: 28.50 C temperature4: 30.20 C vin_undervolt_fault: no overtemperature_warning: no fan_fault: no fan_warning: no fan_status: ok
That fan-util.sh script being this:
https://github.com/linkedin/o19-bmc-firmware/blob/master/meta-openbmc/meta-linkedin/meta-deltapower/recipes-deltapower/liutils/files/fan-util.sh
which invokes this:
https://github.com/linkedin/o19-bmc-firmware/blob/master/meta-openbmc/meta-linkedin/meta-deltapower/recipes-deltapower/liutils/files/fan-ctrl/fan-util.c
(which calls into the routine in powershelf_fan.c linked above).
Zev
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