* [PATCH v3 0/2] hwmon: pmbus: max20730: adjust the vout base on @ 2020-09-24 21:54 Chu Lin 2020-09-24 21:54 ` [PATCH v3 1/2] dt-bindings: hwmon: max20730: adding device tree doc for max20730 Chu Lin 2020-09-24 21:54 ` [PATCH v3 2/2] hwmon: pmbus: max20730: adjust the vout reading given voltage divider Chu Lin 0 siblings, 2 replies; 5+ messages in thread From: Chu Lin @ 2020-09-24 21:54 UTC (permalink / raw) To: linchuyuan, jdelvare, linux, robh+dt, linux-hwmon, devicetree, linux-kernel, qiongwang, zhongqil, jasonling, belgaied The patchset includes: Patch #1 - Implmentation of adjusting vout base on voltage divider Patch #2 - device tree binding documentation ChangeLog v1 -> v2 - Don't do anything to the ret if an error is returned from pmbus_read_word - avoid overflow when doing multiplication ChangeLog v2 -> v3 - Provide the binding documentation in yaml format Chu Lin (2): dt-bindings: hwmon: max20730: adding device tree doc for max20730 hwmon: pmbus: max20730: adjust the vout reading given voltage divider .../bindings/hwmon/maxim,max20730.yaml | 63 +++++++++++++++++++ drivers/hwmon/pmbus/max20730.c | 18 ++++++ 2 files changed, 81 insertions(+) create mode 100644 Documentation/devicetree/bindings/hwmon/maxim,max20730.yaml -- 2.28.0.681.g6f77f65b4e-goog ^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH v3 1/2] dt-bindings: hwmon: max20730: adding device tree doc for max20730 2020-09-24 21:54 [PATCH v3 0/2] hwmon: pmbus: max20730: adjust the vout base on Chu Lin @ 2020-09-24 21:54 ` Chu Lin 2020-09-29 18:56 ` Rob Herring 2020-09-24 21:54 ` [PATCH v3 2/2] hwmon: pmbus: max20730: adjust the vout reading given voltage divider Chu Lin 1 sibling, 1 reply; 5+ messages in thread From: Chu Lin @ 2020-09-24 21:54 UTC (permalink / raw) To: linchuyuan, jdelvare, linux, robh+dt, linux-hwmon, devicetree, linux-kernel, qiongwang, zhongqil, jasonling, belgaied max20730 Integrated, Step-Down Switching Regulator with PMBus Signed-off-by: Chu Lin <linchuyuan@google.com> --- .../bindings/hwmon/maxim,max20730.yaml | 63 +++++++++++++++++++ 1 file changed, 63 insertions(+) create mode 100644 Documentation/devicetree/bindings/hwmon/maxim,max20730.yaml diff --git a/Documentation/devicetree/bindings/hwmon/maxim,max20730.yaml b/Documentation/devicetree/bindings/hwmon/maxim,max20730.yaml new file mode 100644 index 000000000000..7372b27334c3 --- /dev/null +++ b/Documentation/devicetree/bindings/hwmon/maxim,max20730.yaml @@ -0,0 +1,63 @@ +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause) +%YAML 1.2 +--- + +$id: http://devicetree.org/schemas/hwmon/maxim,max20730.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Maxim max20730 + +maintainers: + - Jean Delvare <jdelvare@suse.com> + - Guenter Roeck <linux@roeck-us.net> + +description: | + The MAX20730 is a fully integrated, highly efficient switching regulator + with PMBus for applications operating from 4.5V to 16V and requiring + up to 25A (max) load. This single-chip regulator provides extremely + compact, highefficiency power-delivery solutions with high-precision + output voltages and excellent transient response + + Datasheets: + https://datasheets.maximintegrated.com/en/ds/MAX20730.pdf + https://datasheets.maximintegrated.com/en/ds/MAX20734.pdf + https://datasheets.maximintegrated.com/en/ds/MAX20743.pdf + +properties: + compatible: + enum: + - maxim,max20730 + - maxim,max20734 + - maxim,max20743 + + reg: + maxItems: 1 + + vout-voltage-divider: + description: | + If voltage divider presents at vout, the voltage at voltage sensor pin + will be scaled. The properties will convert the raw reading to a more + meaningful number if voltage divider presents. It has two numbers, + the first number is the output resistor, the second number is the total + resistance. Therefore, the adjusted vout is equal to + Vout = Vout * output_resistance / total resistance. + $ref: /schemas/types.yaml#/definitions/uint32-array + minItems: 2 + maxItems: 2 + +required: + - compatible + - reg + +examples: + - | + i2c { + #address-cells = <1>; + #size-cells = <0>; + + max20730@10 { + compatible = "maxim,max20730"; + reg = <0x10>; + vout-voltage-divider = <1000 2000>; // vout would be scaled to 0.5 + }; + }; -- 2.28.0.681.g6f77f65b4e-goog ^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH v3 1/2] dt-bindings: hwmon: max20730: adding device tree doc for max20730 2020-09-24 21:54 ` [PATCH v3 1/2] dt-bindings: hwmon: max20730: adding device tree doc for max20730 Chu Lin @ 2020-09-29 18:56 ` Rob Herring 0 siblings, 0 replies; 5+ messages in thread From: Rob Herring @ 2020-09-29 18:56 UTC (permalink / raw) To: Chu Lin Cc: jdelvare, linux, linux-hwmon, devicetree, linux-kernel, qiongwang, zhongqil, jasonling, belgaied On Thu, Sep 24, 2020 at 09:54:43PM +0000, Chu Lin wrote: > max20730 Integrated, Step-Down Switching Regulator with PMBus > > Signed-off-by: Chu Lin <linchuyuan@google.com> > --- > .../bindings/hwmon/maxim,max20730.yaml | 63 +++++++++++++++++++ > 1 file changed, 63 insertions(+) > create mode 100644 Documentation/devicetree/bindings/hwmon/maxim,max20730.yaml > > diff --git a/Documentation/devicetree/bindings/hwmon/maxim,max20730.yaml b/Documentation/devicetree/bindings/hwmon/maxim,max20730.yaml > new file mode 100644 > index 000000000000..7372b27334c3 > --- /dev/null > +++ b/Documentation/devicetree/bindings/hwmon/maxim,max20730.yaml > @@ -0,0 +1,63 @@ > +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause) > +%YAML 1.2 > +--- > + > +$id: http://devicetree.org/schemas/hwmon/maxim,max20730.yaml# > +$schema: http://devicetree.org/meta-schemas/core.yaml# > + > +title: Maxim max20730 > + > +maintainers: > + - Jean Delvare <jdelvare@suse.com> > + - Guenter Roeck <linux@roeck-us.net> > + > +description: | > + The MAX20730 is a fully integrated, highly efficient switching regulator > + with PMBus for applications operating from 4.5V to 16V and requiring > + up to 25A (max) load. This single-chip regulator provides extremely > + compact, highefficiency power-delivery solutions with high-precision space ^ > + output voltages and excellent transient response period needed > + > + Datasheets: > + https://datasheets.maximintegrated.com/en/ds/MAX20730.pdf > + https://datasheets.maximintegrated.com/en/ds/MAX20734.pdf > + https://datasheets.maximintegrated.com/en/ds/MAX20743.pdf > + > +properties: > + compatible: > + enum: > + - maxim,max20730 > + - maxim,max20734 > + - maxim,max20743 > + > + reg: > + maxItems: 1 > + > + vout-voltage-divider: > + description: | > + If voltage divider presents at vout, the voltage at voltage sensor pin > + will be scaled. The properties will convert the raw reading to a more > + meaningful number if voltage divider presents. It has two numbers, s/presents/present/ > + the first number is the output resistor, the second number is the total > + resistance. Therefore, the adjusted vout is equal to > + Vout = Vout * output_resistance / total resistance. > + $ref: /schemas/types.yaml#/definitions/uint32-array > + minItems: 2 > + maxItems: 2 > + > +required: > + - compatible > + - reg additionalProperties: false > + > +examples: > + - | > + i2c { > + #address-cells = <1>; > + #size-cells = <0>; > + > + max20730@10 { > + compatible = "maxim,max20730"; > + reg = <0x10>; > + vout-voltage-divider = <1000 2000>; // vout would be scaled to 0.5 > + }; > + }; > -- > 2.28.0.681.g6f77f65b4e-goog > ^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH v3 2/2] hwmon: pmbus: max20730: adjust the vout reading given voltage divider 2020-09-24 21:54 [PATCH v3 0/2] hwmon: pmbus: max20730: adjust the vout base on Chu Lin 2020-09-24 21:54 ` [PATCH v3 1/2] dt-bindings: hwmon: max20730: adding device tree doc for max20730 Chu Lin @ 2020-09-24 21:54 ` Chu Lin 2020-09-30 5:24 ` Guenter Roeck 1 sibling, 1 reply; 5+ messages in thread From: Chu Lin @ 2020-09-24 21:54 UTC (permalink / raw) To: linchuyuan, jdelvare, linux, robh+dt, linux-hwmon, devicetree, linux-kernel, qiongwang, zhongqil, jasonling, belgaied Problem: We use voltage dividers so that the voltage presented at the voltage sense pins is confusing. We might need to convert these readings to more meaningful readings given the voltage divider. Solution: Read the voltage divider resistance from dts and convert the voltage reading to a more meaningful reading. Testing: max20730 with voltage divider Signed-off-by: Chu Lin <linchuyuan@google.com> --- drivers/hwmon/pmbus/max20730.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/drivers/hwmon/pmbus/max20730.c b/drivers/hwmon/pmbus/max20730.c index a151a2b588a5..fbf2f1e6c969 100644 --- a/drivers/hwmon/pmbus/max20730.c +++ b/drivers/hwmon/pmbus/max20730.c @@ -31,6 +31,7 @@ struct max20730_data { struct pmbus_driver_info info; struct mutex lock; /* Used to protect against parallel writes */ u16 mfr_devset1; + u32 vout_voltage_divider[2]; }; #define to_max20730_data(x) container_of(x, struct max20730_data, info) @@ -114,6 +115,14 @@ static int max20730_read_word_data(struct i2c_client *client, int page, max_c = max_current[data->id][(data->mfr_devset1 >> 5) & 0x3]; ret = val_to_direct(max_c, PSC_CURRENT_OUT, info); break; + case PMBUS_READ_VOUT: + ret = pmbus_read_word_data(client, page, phase, reg); + if (ret > 0 && data->vout_voltage_divider[0] && data->vout_voltage_divider[1]) { + u64 temp = DIV_ROUND_CLOSEST_ULL((u64)ret * data->vout_voltage_divider[1], + data->vout_voltage_divider[0]); + ret = clamp_val(temp, 0, 0xffff); + } + break; default: ret = -ENODATA; break; @@ -364,6 +373,15 @@ static int max20730_probe(struct i2c_client *client, data->id = chip_id; mutex_init(&data->lock); memcpy(&data->info, &max20730_info[chip_id], sizeof(data->info)); + if (of_property_read_u32_array(client->dev.of_node, "vout-voltage-divider", + data->vout_voltage_divider, + ARRAY_SIZE(data->vout_voltage_divider)) != 0) + memset(data->vout_voltage_divider, 0, sizeof(data->vout_voltage_divider)); + if (data->vout_voltage_divider[1] < data->vout_voltage_divider[0]) { + dev_err(dev, + "The total resistance of voltage divider is less than output resistance\n"); + return -ENODEV; + } ret = i2c_smbus_read_word_data(client, MAX20730_MFR_DEVSET1); if (ret < 0) -- 2.28.0.681.g6f77f65b4e-goog ^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH v3 2/2] hwmon: pmbus: max20730: adjust the vout reading given voltage divider 2020-09-24 21:54 ` [PATCH v3 2/2] hwmon: pmbus: max20730: adjust the vout reading given voltage divider Chu Lin @ 2020-09-30 5:24 ` Guenter Roeck 0 siblings, 0 replies; 5+ messages in thread From: Guenter Roeck @ 2020-09-30 5:24 UTC (permalink / raw) To: Chu Lin Cc: jdelvare, robh+dt, linux-hwmon, devicetree, linux-kernel, qiongwang, zhongqil, jasonling, belgaied On Thu, Sep 24, 2020 at 09:54:44PM +0000, Chu Lin wrote: > Problem: > We use voltage dividers so that the voltage presented at the voltage > sense pins is confusing. We might need to convert these readings to more > meaningful readings given the voltage divider. > > Solution: > Read the voltage divider resistance from dts and convert the voltage > reading to a more meaningful reading. > > Testing: > max20730 with voltage divider > > Signed-off-by: Chu Lin <linchuyuan@google.com> > --- <Formletter> Change log goes here. If it is missing, I won't know what changed. That means I will have to dig out older patch versions to compare. That costs time and will hold up both this patch as well as all other patches which I still have to review. Please keep this in mind when submitting patch revisions without change log. </Formletter> Worse, this is v3, and I had given v2 a Reviewed-by: tag which was dropped. This means I have to compare the two versions to figure out what changed, probably just to find out that nothing has changed since v2. Patches like this are the reason why various patches won't make it into the next kernel release. Sorry, I just don't have as much time as people seem to think I have. Guenter > drivers/hwmon/pmbus/max20730.c | 18 ++++++++++++++++++ > 1 file changed, 18 insertions(+) > > diff --git a/drivers/hwmon/pmbus/max20730.c b/drivers/hwmon/pmbus/max20730.c > index a151a2b588a5..fbf2f1e6c969 100644 > --- a/drivers/hwmon/pmbus/max20730.c > +++ b/drivers/hwmon/pmbus/max20730.c > @@ -31,6 +31,7 @@ struct max20730_data { > struct pmbus_driver_info info; > struct mutex lock; /* Used to protect against parallel writes */ > u16 mfr_devset1; > + u32 vout_voltage_divider[2]; > }; > > #define to_max20730_data(x) container_of(x, struct max20730_data, info) > @@ -114,6 +115,14 @@ static int max20730_read_word_data(struct i2c_client *client, int page, > max_c = max_current[data->id][(data->mfr_devset1 >> 5) & 0x3]; > ret = val_to_direct(max_c, PSC_CURRENT_OUT, info); > break; > + case PMBUS_READ_VOUT: > + ret = pmbus_read_word_data(client, page, phase, reg); > + if (ret > 0 && data->vout_voltage_divider[0] && data->vout_voltage_divider[1]) { > + u64 temp = DIV_ROUND_CLOSEST_ULL((u64)ret * data->vout_voltage_divider[1], > + data->vout_voltage_divider[0]); > + ret = clamp_val(temp, 0, 0xffff); > + } > + break; > default: > ret = -ENODATA; > break; > @@ -364,6 +373,15 @@ static int max20730_probe(struct i2c_client *client, > data->id = chip_id; > mutex_init(&data->lock); > memcpy(&data->info, &max20730_info[chip_id], sizeof(data->info)); > + if (of_property_read_u32_array(client->dev.of_node, "vout-voltage-divider", > + data->vout_voltage_divider, > + ARRAY_SIZE(data->vout_voltage_divider)) != 0) > + memset(data->vout_voltage_divider, 0, sizeof(data->vout_voltage_divider)); > + if (data->vout_voltage_divider[1] < data->vout_voltage_divider[0]) { > + dev_err(dev, > + "The total resistance of voltage divider is less than output resistance\n"); > + return -ENODEV; > + } > > ret = i2c_smbus_read_word_data(client, MAX20730_MFR_DEVSET1); > if (ret < 0) ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2020-09-30 5:24 UTC | newest] Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2020-09-24 21:54 [PATCH v3 0/2] hwmon: pmbus: max20730: adjust the vout base on Chu Lin 2020-09-24 21:54 ` [PATCH v3 1/2] dt-bindings: hwmon: max20730: adding device tree doc for max20730 Chu Lin 2020-09-29 18:56 ` Rob Herring 2020-09-24 21:54 ` [PATCH v3 2/2] hwmon: pmbus: max20730: adjust the vout reading given voltage divider Chu Lin 2020-09-30 5:24 ` Guenter Roeck
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