On 4/29/22 02:52, Marten Lindahl wrote:
On Thu, Apr 28, 2022 at 06:49:21PM +0200, Guenter Roeck wrote:
On 4/28/22 07:40, Mårten Lindahl wrote:
The pmbus core does not have operations for getting or setting voltage.
Add functions get/set voltage for the dynamic regulator framework.
Signed-off-by: Mårten Lindahl <marten.lindahl@xxxxxxxx>
---
drivers/hwmon/pmbus/pmbus_core.c | 63 ++++++++++++++++++++++++++++++++
1 file changed, 63 insertions(+)
diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
index bd143ca0c320..fe7dbb496e3b 100644
--- a/drivers/hwmon/pmbus/pmbus_core.c
+++ b/drivers/hwmon/pmbus/pmbus_core.c
@@ -1531,6 +1531,11 @@ static const struct pmbus_sensor_attr voltage_attributes[] = {
.gbit = PB_STATUS_VOUT_OV,
.limit = vout_limit_attrs,
.nlimit = ARRAY_SIZE(vout_limit_attrs),
+ }, {
+ .reg = PMBUS_VOUT_COMMAND,
+ .class = PSC_VOLTAGE_OUT,
+ .paged = true,
+ .func = PMBUS_HAVE_VOUT,
}
Ok, you lost me here. This adds an inX_input attribute. Why ? This is completely
unrelated to the intended scope of this patch. It also doesn't report a measured
voltage, but a configuration value. If anything, it would have to be a separate
patch, and you'd have to argue hard why it makes sense to report it as measured
voltage.
I see. The reason for adding this is as simple as I now understand it is wrong.
Please remember, my first version of the set/get_voltage functions where hardcoded
with L16 input/output. Then in order to use the already existing convertion functions
pmbus_data2reg and pmbus_reg2data I added this only for the need of a sensor object,
as those functions are tailored for a sensor object.
So now I have to ask you for advice. Should I use the existing convertion
functions, or do you suggest new variants of them? If reusing them, I guess I have
two options:
1: Modify them to take class, page, and data outside of a sensor object as input.
2: Use them as they are, but create a local 'dummy' sensor object with class, page,
and data to use when calling the convertion functions.
I think 2) is the easier and less complex solution for now.
I hope I made it more clear for you now how I was thinking. There is
absolutely no intention of having sensor inX_input attributes for
reading the setpoint values. This was just an unwanted sideeffect, and I
will glady remove it again.
No problem. Thanks for the explanation.
};
@@ -2563,11 +2568,69 @@ static int pmbus_regulator_get_error_flags(struct regulator_dev *rdev, unsigned
return 0;
}
+static int pmbus_regulator_get_voltage(struct regulator_dev *rdev)
+{
+ struct device *dev = rdev_get_dev(rdev);
+ struct i2c_client *client = to_i2c_client(dev->parent);
+ struct pmbus_data *data = i2c_get_clientdata(client);
+ struct pmbus_sensor *sensor;
+ u8 page = rdev_get_id(rdev);
+ int ret;
+
+ sensor = pmbus_find_sensor(data, page, PMBUS_READ_VOUT);
+ if (IS_ERR(sensor))
+ return -ENODATA;
+
+ mutex_lock(&data->update_lock);
+ pmbus_update_sensor_data(client, sensor);
+ if (sensor->data < 0)
+ ret = sensor->data;
+ else
+ ret = (int)pmbus_reg2data(data, sensor) * 1000; /* unit is uV */
+ mutex_unlock(&data->update_lock);
+
Same question. Why ?
Same reason as above. Only to get the sensor object for pmbus_reg2data.
+ return ret;
+}
+
+static int pmbus_regulator_set_voltage(struct regulator_dev *rdev, int min_uV,
+ int max_uV, unsigned int *selector)
+{
+ struct device *dev = rdev_get_dev(rdev);
+ struct i2c_client *client = to_i2c_client(dev->parent);
+ struct pmbus_data *data = i2c_get_clientdata(client);
+ struct pmbus_sensor *sensor;
+ u8 page = rdev_get_id(rdev);
+ s64 tmp = DIV_ROUND_CLOSEST_ULL(min_uV, 1000); /* convert to mV */
+ u16 val;
+ int ret;
+ *selector = 0;
+
+ sensor = pmbus_find_sensor(data, page, PMBUS_VOUT_COMMAND);
+ if (IS_ERR(sensor))
+ return -ENODATA;
+
+ ret = _pmbus_read_word_data(client, page, 0xff, PMBUS_VOUT_MARGIN_LOW);
+ if (ret < 0)
+ return ret;
+
That actually makes me wonder: What about VOUT_MARGIN_HIGH ?
Ok, I will add a check for VOUT_MARGIN_HIGH also.
Also, there are optional MFR_VOUT_MIN and MFR_VOUT_MAX registers.
Would it possibly make sense to determine the valid range once
during probe and then compare against it ?
Maybe this could be a good thing, so that we don't need to read both
margins every time. But I guess that would need a new kind of page list
with margins added to the pmbus_driver_info struct?
I would prefer to make that change in a separate patch if it's ok with
you?
I think you need to check for four values right now:
- Try to read MFR_VOUT_MIN. If that does not work, read VOUT_MARGIN_LOW.
- Same for high values.
Ultimately, yes, I think we should add a list of limits. I think it
would make more sense though to add the limits to a new regulator
specific data structure. Maybe we should create a separate data structure
for regulators. Right now we pass struct pmbus_data. Maybe we need
struct pmbus_regulator_data which would contain a pointer to
struct pmbus_data as well as additional information needed for
regulators.
Thanks,
Guenter
