On 7/28/21 2:38 AM, Paul Menzel wrote:
From: Madhava Reddy Siddareddygari <msiddare@xxxxxxxxx>
PSU650W has four temperature sensors, while the pmbus driver currently
only support three temperature sensors.
So, support a fourth temp sensor, i. e. PSU outlet temperature sensor,
by copying what is done for temperature sensor 3, and use register 0xDF.
PSU650W is based on LITE-ON vendor.
LITE-ON MFG part numbers for the PSU are PS-2651-3SB5 Z and PS-2651-3SA5 Z.
Signed-off-by: Madhava Reddy Siddareddygari <msiddare@xxxxxxxxx>
Signed-off-by: Venkat Garigipati <venkatg@xxxxxxxxx>
Cc: Billie Alsup <balsup@xxxxxxxxx>
Signed-off-by: Paul Menzel <pmenzel@xxxxxxxxxxxxx>
---
This as a RFC, as we know 0xDF is a manufacturer specific register, and
cannot be added to the PMBus core driver. It was submitted to SONiC [1]
by Cisco engineers.
It’d be great if the maintainers good suggest how to easily implement a
custom driver for that PSU?
Implement a chip driver with a set of read/write functions.
Claim it has two pages, with the second page only implementing a single
temperature sensor. In the read/write functions, handle page 0 normally,
and access the second sensor whenever page 1 is accessed.
[1]: https://github.com/Azure/sonic-linux-kernel/pull/214
The comments there are a bit concerning.
"* Virtual registers.
* Useful to support attributes which are not supported by standard PMBus
* registers but exist as manufacturer specific registers on individual chips.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
* Must be mapped to real registers in device specific code.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
"
Then,
"... is Manufacturer specific command. These are not Virtual registers."
Isn't that exactly what the "Virtual registers" description states ?
How can that be explained better ?
Either case, I see no need to define a virtual register for a 4th temperature
sensor. This can easily be implemented with the mechanism described above.
Guenter
drivers/hwmon/pmbus/pmbus.c | 4 +++-
drivers/hwmon/pmbus/pmbus.h | 3 +++
drivers/hwmon/pmbus/pmbus_core.c | 38 ++++++++++++++++++++++++++++++++
3 files changed, 44 insertions(+), 1 deletion(-)
diff --git a/drivers/hwmon/pmbus/pmbus.c b/drivers/hwmon/pmbus/pmbus.c
index d0d386990af5..df2a782a1105 100644
--- a/drivers/hwmon/pmbus/pmbus.c
+++ b/drivers/hwmon/pmbus/pmbus.c
@@ -60,8 +60,10 @@ static void pmbus_find_sensor_groups(struct i2c_client *client,
info->func[0] |= PMBUS_HAVE_TEMP2;
if (pmbus_check_word_register(client, 0, PMBUS_READ_TEMPERATURE_3))
info->func[0] |= PMBUS_HAVE_TEMP3;
+ if (pmbus_check_word_register(client, 0, PMBUS_READ_TEMPERATURE_4))
+ info->func[0] |= PMBUS_HAVE_TEMP4;
if (info->func[0] & (PMBUS_HAVE_TEMP | PMBUS_HAVE_TEMP2
- | PMBUS_HAVE_TEMP3)
+ | PMBUS_HAVE_TEMP3 | PMBUS_HAVE_TEMP4)
&& pmbus_check_byte_register(client, 0,
PMBUS_STATUS_TEMPERATURE))
info->func[0] |= PMBUS_HAVE_STATUS_TEMP;
diff --git a/drivers/hwmon/pmbus/pmbus.h b/drivers/hwmon/pmbus/pmbus.h
index e0aa8aa46d8c..1522c8c7cade 100644
--- a/drivers/hwmon/pmbus/pmbus.h
+++ b/drivers/hwmon/pmbus/pmbus.h
@@ -135,6 +135,8 @@ enum pmbus_regs {
PMBUS_MFR_MAX_TEMP_2 = 0xC1,
PMBUS_MFR_MAX_TEMP_3 = 0xC2,
+ PMBUS_READ_TEMPERATURE_4 = 0xDF,
+
/*
* Virtual registers.
* Useful to support attributes which are not supported by standard PMBus
@@ -401,6 +403,7 @@ enum pmbus_sensor_classes {
#define PMBUS_HAVE_PWM12 BIT(20)
#define PMBUS_HAVE_PWM34 BIT(21)
#define PMBUS_HAVE_SAMPLES BIT(22)
+#define PMBUS_HAVE_TEMP4 BIT(23)
#define PMBUS_PHASE_VIRTUAL BIT(30) /* Phases on this page are virtual */
#define PMBUS_PAGE_VIRTUAL BIT(31) /* Page is virtual */
diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
index 776ee2237be2..b084b5ba6d45 100644
--- a/drivers/hwmon/pmbus/pmbus_core.c
+++ b/drivers/hwmon/pmbus/pmbus_core.c
@@ -1810,6 +1810,32 @@ static const struct pmbus_limit_attr temp_limit_attrs3[] = {
},
};
+static const struct pmbus_limit_attr temp_limit_attrs4[] = {
+ {
+ .reg = PMBUS_UT_WARN_LIMIT,
+ .low = true,
+ .attr = "min",
+ .alarm = "min_alarm",
+ .sbit = PB_TEMP_UT_WARNING,
+ }, {
+ .reg = PMBUS_UT_FAULT_LIMIT,
+ .low = true,
+ .attr = "lcrit",
+ .alarm = "lcrit_alarm",
+ .sbit = PB_TEMP_UT_FAULT,
+ }, {
+ .reg = PMBUS_OT_WARN_LIMIT,
+ .attr = "max",
+ .alarm = "max_alarm",
+ .sbit = PB_TEMP_OT_WARNING,
+ }, {
+ .reg = PMBUS_OT_FAULT_LIMIT,
+ .attr = "crit",
+ .alarm = "crit_alarm",
+ .sbit = PB_TEMP_OT_FAULT,
+ }
+};
+
static const struct pmbus_sensor_attr temp_attributes[] = {
{
.reg = PMBUS_READ_TEMPERATURE_1,
@@ -1847,6 +1873,18 @@ static const struct pmbus_sensor_attr temp_attributes[] = {
.gbit = PB_STATUS_TEMPERATURE,
.limit = temp_limit_attrs3,
.nlimit = ARRAY_SIZE(temp_limit_attrs3),
+ }, {
+ .reg = PMBUS_READ_TEMPERATURE_4,
+ .class = PSC_TEMPERATURE,
+ .paged = true,
+ .update = true,
+ .compare = true,
+ .func = PMBUS_HAVE_TEMP4,
+ .sfunc = PMBUS_HAVE_STATUS_TEMP,
+ .sbase = PB_STATUS_TEMP_BASE,
+ .gbit = PB_STATUS_TEMPERATURE,
+ .limit = temp_limit_attrs4,
+ .nlimit = ARRAY_SIZE(temp_limit_attrs4),
}
};
