| Message ID | 20210928092242.30036-8-zev@bewilderbeest.net (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | hwmon: (pmbus/lm25066) Configurable sense resistor, other cleanups | expand |
On Tue, Sep 28, 2021 at 02:22:41AM -0700, Zev Weiss wrote: > The appropriate mantissa values for the lm25066 family's direct-format > current and power readings are a function of the sense resistor > employed between the SENSE and VIN pins of the chip. Instead of > assuming that resistance is always the same 1mOhm as used in the > datasheet, allow it to be configured via a device-tree property > ("shunt-resistor-micro-ohms"). > > Signed-off-by: Zev Weiss <zev@bewilderbeest.net> > --- > Documentation/hwmon/lm25066.rst | 2 ++ > drivers/hwmon/pmbus/lm25066.c | 12 ++++++++++++ > 2 files changed, 14 insertions(+) > > diff --git a/Documentation/hwmon/lm25066.rst b/Documentation/hwmon/lm25066.rst > index 9f1d7e4d3ca1..a2098eb24090 100644 > --- a/Documentation/hwmon/lm25066.rst > +++ b/Documentation/hwmon/lm25066.rst > @@ -79,6 +79,8 @@ This driver does not auto-detect devices. You will have to instantiate the > devices explicitly. Please see Documentation/i2c/instantiating-devices.rst for > details. > > +The shunt (sense) resistor value can be configured by a device tree property; > +see Documentation/devicetree/bindings/hwmon/pmbus/ti,lm25066.yaml for details. > > Platform data support > --------------------- > diff --git a/drivers/hwmon/pmbus/lm25066.c b/drivers/hwmon/pmbus/lm25066.c > index 18d5a76f346d..29e848bcd436 100644 > --- a/drivers/hwmon/pmbus/lm25066.c > +++ b/drivers/hwmon/pmbus/lm25066.c > @@ -458,6 +458,7 @@ MODULE_DEVICE_TABLE(of, lm25066_of_match); > static int lm25066_probe(struct i2c_client *client) > { > int config; > + u32 shunt; > struct lm25066_data *data; > struct pmbus_driver_info *info; > const struct __coeff *coeff; > @@ -535,6 +536,17 @@ static int lm25066_probe(struct i2c_client *client) > info->b[PSC_POWER] = coeff[PSC_POWER].b; > } > > + /* > + * Values in the TI datasheets are normalized for a 1mOhm sense > + * resistor; assume that unless DT specifies a value explicitly. > + */ > + if (of_property_read_u32(client->dev.of_node, > + "shunt-resistor-micro-ohms", &shunt)) Space vs. tabs again. Never mind, fixed up and applied. Thanks, Guenter > + shunt = 1000; > + > + info->m[PSC_CURRENT_IN] = info->m[PSC_CURRENT_IN] * shunt / 1000; > + info->m[PSC_POWER] = info->m[PSC_POWER] * shunt / 1000; > + > return pmbus_do_probe(client, info); > } >
diff --git a/Documentation/hwmon/lm25066.rst b/Documentation/hwmon/lm25066.rst index 9f1d7e4d3ca1..a2098eb24090 100644 --- a/Documentation/hwmon/lm25066.rst +++ b/Documentation/hwmon/lm25066.rst @@ -79,6 +79,8 @@ This driver does not auto-detect devices. You will have to instantiate the devices explicitly. Please see Documentation/i2c/instantiating-devices.rst for details. +The shunt (sense) resistor value can be configured by a device tree property; +see Documentation/devicetree/bindings/hwmon/pmbus/ti,lm25066.yaml for details. Platform data support --------------------- diff --git a/drivers/hwmon/pmbus/lm25066.c b/drivers/hwmon/pmbus/lm25066.c index 18d5a76f346d..29e848bcd436 100644 --- a/drivers/hwmon/pmbus/lm25066.c +++ b/drivers/hwmon/pmbus/lm25066.c @@ -458,6 +458,7 @@ MODULE_DEVICE_TABLE(of, lm25066_of_match); static int lm25066_probe(struct i2c_client *client) { int config; + u32 shunt; struct lm25066_data *data; struct pmbus_driver_info *info; const struct __coeff *coeff; @@ -535,6 +536,17 @@ static int lm25066_probe(struct i2c_client *client) info->b[PSC_POWER] = coeff[PSC_POWER].b; } + /* + * Values in the TI datasheets are normalized for a 1mOhm sense + * resistor; assume that unless DT specifies a value explicitly. + */ + if (of_property_read_u32(client->dev.of_node, + "shunt-resistor-micro-ohms", &shunt)) + shunt = 1000; + + info->m[PSC_CURRENT_IN] = info->m[PSC_CURRENT_IN] * shunt / 1000; + info->m[PSC_POWER] = info->m[PSC_POWER] * shunt / 1000; + return pmbus_do_probe(client, info); }
The appropriate mantissa values for the lm25066 family's direct-format current and power readings are a function of the sense resistor employed between the SENSE and VIN pins of the chip. Instead of assuming that resistance is always the same 1mOhm as used in the datasheet, allow it to be configured via a device-tree property ("shunt-resistor-micro-ohms"). Signed-off-by: Zev Weiss <zev@bewilderbeest.net> --- Documentation/hwmon/lm25066.rst | 2 ++ drivers/hwmon/pmbus/lm25066.c | 12 ++++++++++++ 2 files changed, 14 insertions(+)