* [PATCH v7 1/2] hwmon: (pmbus/isl68137) add support for voltage divider on Vout
2024-11-12 20:07 [PATCH v7 0/2] dt-bindings: hwmon: pmbus: add bindings for isl68137 Grant Peltier
@ 2024-11-12 20:09 ` Grant Peltier
2024-11-13 20:08 ` Guenter Roeck
2024-11-12 20:10 ` [PATCH v7 2/2] dt-bindings: hwmon: isl68137: add bindings to support voltage dividers Grant Peltier
1 sibling, 1 reply; 6+ messages in thread
From: Grant Peltier @ 2024-11-12 20:09 UTC (permalink / raw)
To: robh, linux, geert+renesas, magnus.damm
Cc: grant.peltier.jg, brandon.howell.jg, linux-hwmon, devicetree,
linux-doc
Some applications require Vout to be higher than the detectable voltage
range of the Vsense pin for a given rail. In such applications, a voltage
divider may be placed between Vout and the Vsense pin, but this results
in erroneous telemetry being read back from the part. This change adds
support for a voltage divider to be defined in the devicetree for a (or
multiple) specific rail(s) for a supported digital multiphase device and
for the applicable Vout telemetry to be scaled based on the voltage
divider configuration.
This change copies the implementation of the vout-voltage-divider
devicetree property defined in the maxim,max20730 bindings schema since
it is the best fit for the use case of scaling hwmon PMBus telemetry. The
generic voltage-divider property used by many iio drivers was determined
to be a poor fit because that schema is tied directly to iio and the
isl68137 driver is not an iio driver.
Signed-off-by: Grant Peltier <grantpeltier93@gmail.com>
---
drivers/hwmon/pmbus/isl68137.c | 210 ++++++++++++++++++++++++++++++++-
1 file changed, 205 insertions(+), 5 deletions(-)
diff --git a/drivers/hwmon/pmbus/isl68137.c b/drivers/hwmon/pmbus/isl68137.c
index 7e53fb1d5ea3..97cc951a13a4 100644
--- a/drivers/hwmon/pmbus/isl68137.c
+++ b/drivers/hwmon/pmbus/isl68137.c
@@ -13,6 +13,7 @@
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
+#include <linux/of.h>
#include <linux/string.h>
#include <linux/sysfs.h>
@@ -20,6 +21,7 @@
#define ISL68137_VOUT_AVS 0x30
#define RAA_DMPVR2_READ_VMON 0xc8
+#define MAX_CHANNELS 4
enum chips {
isl68137,
@@ -72,6 +74,17 @@ enum variants {
raa_dmpvr2_hv,
};
+struct isl68137_channel {
+ u32 vout_voltage_divider[2];
+};
+
+struct isl68137_data {
+ struct pmbus_driver_info info;
+ struct isl68137_channel channel[MAX_CHANNELS];
+};
+
+#define to_isl68137_data(x) container_of(x, struct isl68137_data, info)
+
static const struct i2c_device_id raa_dmpvr_id[];
static ssize_t isl68137_avs_enable_show_page(struct i2c_client *client,
@@ -163,13 +176,32 @@ static const struct attribute_group *isl68137_attribute_groups[] = {
static int raa_dmpvr2_read_word_data(struct i2c_client *client, int page,
int phase, int reg)
{
+ const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
+ const struct isl68137_data *data = to_isl68137_data(info);
int ret;
+ u64 temp;
switch (reg) {
case PMBUS_VIRT_READ_VMON:
ret = pmbus_read_word_data(client, page, phase,
RAA_DMPVR2_READ_VMON);
break;
+ case PMBUS_READ_POUT:
+ case PMBUS_READ_VOUT:
+ /*
+ * In cases where a voltage divider is attached to the target
+ * rail between Vout and the Vsense pin, both Vout and Pout
+ * should be scaled by the voltage divider scaling factor.
+ * I.e. Vout = Vsense * Rtotal / Rout
+ */
+ ret = pmbus_read_word_data(client, page, phase, reg);
+ if (ret > 0) {
+ temp = DIV_U64_ROUND_CLOSEST((u64)ret *
+ data->channel[page].vout_voltage_divider[1],
+ data->channel[page].vout_voltage_divider[0]);
+ ret = clamp_val(temp, 0, 0xffff);
+ }
+ break;
default:
ret = -ENODATA;
break;
@@ -178,6 +210,40 @@ static int raa_dmpvr2_read_word_data(struct i2c_client *client, int page,
return ret;
}
+static int raa_dmpvr2_write_word_data(struct i2c_client *client, int page,
+ int reg, u16 word)
+{
+ const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
+ const struct isl68137_data *data = to_isl68137_data(info);
+ int ret;
+ u64 temp;
+
+ switch (reg) {
+ case PMBUS_VOUT_MAX:
+ case PMBUS_VOUT_MARGIN_HIGH:
+ case PMBUS_VOUT_MARGIN_LOW:
+ case PMBUS_VOUT_OV_FAULT_LIMIT:
+ case PMBUS_VOUT_UV_FAULT_LIMIT:
+ case PMBUS_VOUT_COMMAND:
+ /*
+ * In cases where a voltage divider is attached to the target
+ * rail between Vout and the Vsense pin, Vout related PMBus
+ * commands should be scaled based on the expected voltage
+ * at the Vsense pin.
+ * I.e. Vsense = Vout * Rout / Rtotal
+ */
+ temp = DIV_U64_ROUND_CLOSEST((u64)word *
+ data->channel[page].vout_voltage_divider[0],
+ data->channel[page].vout_voltage_divider[1]);
+ ret = clamp_val(temp, 0, 0xffff);
+ break;
+ default:
+ ret = -ENODATA;
+ break;
+ }
+ return ret;
+}
+
static struct pmbus_driver_info raa_dmpvr_info = {
.pages = 3,
.format[PSC_VOLTAGE_IN] = direct,
@@ -220,14 +286,90 @@ static struct pmbus_driver_info raa_dmpvr_info = {
| PMBUS_HAVE_STATUS_IOUT | PMBUS_HAVE_POUT,
};
+static int isl68137_probe_child_from_dt(struct device *dev,
+ struct device_node *child,
+ struct isl68137_data *data)
+{
+ u32 channel, rout, rtotal;
+ int err;
+
+ err = of_property_read_u32(child, "reg", &channel);
+ if (err) {
+ dev_err(dev, "missing reg property of %pOFn\n", child);
+ return err;
+ }
+ if (channel >= data->info.pages) {
+ dev_err(dev, "invalid reg %d of %pOFn\n", channel, child);
+ return -EINVAL;
+ }
+
+ err = of_property_read_u32_array(child, "vout-voltage-divider",
+ data->channel[channel].vout_voltage_divider,
+ ARRAY_SIZE(data->channel[channel].vout_voltage_divider));
+ if (err && err != -EINVAL) {
+ dev_err(dev,
+ "malformed vout-voltage-divider value for channel %d\n",
+ channel);
+ return err;
+ }
+
+ rout = data->channel[channel].vout_voltage_divider[0];
+ rtotal = data->channel[channel].vout_voltage_divider[1];
+ if (rout == 0) {
+ dev_err(dev,
+ "Voltage divider output resistance must be greater than 0\n");
+ return -EINVAL;
+ }
+ if (rtotal < rout) {
+ dev_err(dev,
+ "Voltage divider total resistance is less than output resistance\n");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int isl68137_probe_from_dt(struct device *dev,
+ struct isl68137_data *data)
+{
+ const struct device_node *np = dev->of_node;
+ struct device_node *child;
+ int err;
+
+ for_each_child_of_node(np, child) {
+ if (strcmp(child->name, "channel"))
+ continue;
+
+ err = isl68137_probe_child_from_dt(dev, child, data);
+ if (err)
+ return err;
+ }
+
+ return 0;
+}
+
static int isl68137_probe(struct i2c_client *client)
{
+ struct device *dev = &client->dev;
struct pmbus_driver_info *info;
+ struct isl68137_data *data;
+ int i, err;
- info = devm_kzalloc(&client->dev, sizeof(*info), GFP_KERNEL);
- if (!info)
+ data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+ if (!data)
return -ENOMEM;
- memcpy(info, &raa_dmpvr_info, sizeof(*info));
+
+ /*
+ * Initialize all voltage dividers to Rout=1 and Rtotal=1 to simplify
+ * logic in PMBus word read/write functions
+ */
+ for (i = 0; i < MAX_CHANNELS; i++)
+ memset(data->channel[i].vout_voltage_divider,
+ 1,
+ sizeof(data->channel[i].vout_voltage_divider));
+
+ memcpy(&data->info, &raa_dmpvr_info, sizeof(data->info));
+ info = &data->info;
switch (i2c_match_id(raa_dmpvr_id, client)->driver_data) {
case raa_dmpvr1_2rail:
@@ -237,11 +379,14 @@ static int isl68137_probe(struct i2c_client *client)
info->func[1] = PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
| PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
| PMBUS_HAVE_POUT;
+ info->read_word_data = raa_dmpvr2_read_word_data;
+ info->write_word_data = raa_dmpvr2_write_word_data;
info->groups = isl68137_attribute_groups;
break;
case raa_dmpvr2_1rail:
info->pages = 1;
info->read_word_data = raa_dmpvr2_read_word_data;
+ info->write_word_data = raa_dmpvr2_write_word_data;
break;
case raa_dmpvr2_2rail_nontc:
info->func[0] &= ~PMBUS_HAVE_TEMP3;
@@ -250,9 +395,11 @@ static int isl68137_probe(struct i2c_client *client)
case raa_dmpvr2_2rail:
info->pages = 2;
info->read_word_data = raa_dmpvr2_read_word_data;
+ info->write_word_data = raa_dmpvr2_write_word_data;
break;
case raa_dmpvr2_3rail:
info->read_word_data = raa_dmpvr2_read_word_data;
+ info->write_word_data = raa_dmpvr2_write_word_data;
break;
case raa_dmpvr2_hv:
info->pages = 1;
@@ -263,11 +410,16 @@ static int isl68137_probe(struct i2c_client *client)
info->m[PSC_POWER] = 2;
info->R[PSC_POWER] = -1;
info->read_word_data = raa_dmpvr2_read_word_data;
+ info->write_word_data = raa_dmpvr2_write_word_data;
break;
default:
return -ENODEV;
}
+ err = isl68137_probe_from_dt(dev, data);
+ if (err)
+ return err;
+
return pmbus_do_probe(client, info);
}
@@ -318,11 +470,59 @@ static const struct i2c_device_id raa_dmpvr_id[] = {
MODULE_DEVICE_TABLE(i2c, raa_dmpvr_id);
+static const struct of_device_id isl68137_of_match[] = {
+ { .compatible = "isil,isl68137", .data = (void *)raa_dmpvr1_2rail },
+ { .compatible = "renesas,isl68220", .data = (void *)raa_dmpvr2_2rail },
+ { .compatible = "renesas,isl68221", .data = (void *)raa_dmpvr2_3rail },
+ { .compatible = "renesas,isl68222", .data = (void *)raa_dmpvr2_2rail },
+ { .compatible = "renesas,isl68223", .data = (void *)raa_dmpvr2_2rail },
+ { .compatible = "renesas,isl68224", .data = (void *)raa_dmpvr2_3rail },
+ { .compatible = "renesas,isl68225", .data = (void *)raa_dmpvr2_2rail },
+ { .compatible = "renesas,isl68226", .data = (void *)raa_dmpvr2_3rail },
+ { .compatible = "renesas,isl68227", .data = (void *)raa_dmpvr2_1rail },
+ { .compatible = "renesas,isl68229", .data = (void *)raa_dmpvr2_3rail },
+ { .compatible = "renesas,isl68233", .data = (void *)raa_dmpvr2_2rail },
+ { .compatible = "renesas,isl68239", .data = (void *)raa_dmpvr2_3rail },
+
+ { .compatible = "renesas,isl69222", .data = (void *)raa_dmpvr2_2rail },
+ { .compatible = "renesas,isl69223", .data = (void *)raa_dmpvr2_3rail },
+ { .compatible = "renesas,isl69224", .data = (void *)raa_dmpvr2_2rail },
+ { .compatible = "renesas,isl69225", .data = (void *)raa_dmpvr2_2rail },
+ { .compatible = "renesas,isl69227", .data = (void *)raa_dmpvr2_3rail },
+ { .compatible = "renesas,isl69228", .data = (void *)raa_dmpvr2_3rail },
+ { .compatible = "renesas,isl69234", .data = (void *)raa_dmpvr2_2rail },
+ { .compatible = "renesas,isl69236", .data = (void *)raa_dmpvr2_2rail },
+ { .compatible = "renesas,isl69239", .data = (void *)raa_dmpvr2_3rail },
+ { .compatible = "renesas,isl69242", .data = (void *)raa_dmpvr2_2rail },
+ { .compatible = "renesas,isl69243", .data = (void *)raa_dmpvr2_1rail },
+ { .compatible = "renesas,isl69247", .data = (void *)raa_dmpvr2_2rail },
+ { .compatible = "renesas,isl69248", .data = (void *)raa_dmpvr2_2rail },
+ { .compatible = "renesas,isl69254", .data = (void *)raa_dmpvr2_2rail },
+ { .compatible = "renesas,isl69255", .data = (void *)raa_dmpvr2_2rail },
+ { .compatible = "renesas,isl69256", .data = (void *)raa_dmpvr2_2rail },
+ { .compatible = "renesas,isl69259", .data = (void *)raa_dmpvr2_2rail },
+ { .compatible = "isil,isl69260", .data = (void *)raa_dmpvr2_2rail },
+ { .compatible = "renesas,isl69268", .data = (void *)raa_dmpvr2_2rail },
+ { .compatible = "isil,isl69269", .data = (void *)raa_dmpvr2_3rail },
+ { .compatible = "renesas,isl69298", .data = (void *)raa_dmpvr2_2rail },
+
+ { .compatible = "renesas,raa228000", .data = (void *)raa_dmpvr2_hv },
+ { .compatible = "renesas,raa228004", .data = (void *)raa_dmpvr2_hv },
+ { .compatible = "renesas,raa228006", .data = (void *)raa_dmpvr2_hv },
+ { .compatible = "renesas,raa228228", .data = (void *)raa_dmpvr2_2rail_nontc },
+ { .compatible = "renesas,raa229001", .data = (void *)raa_dmpvr2_2rail },
+ { .compatible = "renesas,raa229004", .data = (void *)raa_dmpvr2_2rail },
+ { },
+};
+
+MODULE_DEVICE_TABLE(of, isl68137_of_match);
+
/* This is the driver that will be inserted */
static struct i2c_driver isl68137_driver = {
.driver = {
- .name = "isl68137",
- },
+ .name = "isl68137",
+ .of_match_table = isl68137_of_match,
+ },
.probe = isl68137_probe,
.id_table = raa_dmpvr_id,
};
--
2.39.5
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH v7 2/2] dt-bindings: hwmon: isl68137: add bindings to support voltage dividers
2024-11-12 20:07 [PATCH v7 0/2] dt-bindings: hwmon: pmbus: add bindings for isl68137 Grant Peltier
2024-11-12 20:09 ` [PATCH v7 1/2] hwmon: (pmbus/isl68137) add support for voltage divider on Vout Grant Peltier
@ 2024-11-12 20:10 ` Grant Peltier
2024-11-13 18:14 ` Rob Herring (Arm)
2024-11-13 20:07 ` Guenter Roeck
1 sibling, 2 replies; 6+ messages in thread
From: Grant Peltier @ 2024-11-12 20:10 UTC (permalink / raw)
To: robh, linux, geert+renesas, magnus.damm
Cc: grant.peltier.jg, brandon.howell.jg, linux-hwmon, devicetree,
linux-doc
Add devicetree bindings to support declaring optional voltage dividers to
the rail outputs of supported digital multiphase regulators. Some
applications require Vout to exceed the voltage range that the Vsense pin
can detect. This binding definition allows users to define the
characteristics of a voltage divider placed between Vout and the Vsense
pin for any rail powered by the device.
These bindings copy the vout-voltage-divider property defined in the
maxim,max20730 bindings schema since it is the best fit for the use case
of scaling hwmon PMBus telemetry. The generic voltage-divider property
used by many iio drivers was determined to be a poor fit because that
schema is tied directly to iio for the purpose of scaling io-channel
voltages and the isl68137 driver is not an iio driver.
New schema file named isil,isl68137.yaml to align with the corresponding
driver name and pre-existing bindings ported from trivial bindings.
However, all new device bindings use renesas as the vendor prefix
since Renesas acquired Intersil and now maintains all documentation
for the devices.
Signed-off-by: Grant Peltier <grantpeltier93@gmail.com>
---
.../bindings/hwmon/pmbus/isil,isl68137.yaml | 148 ++++++++++++++++++
.../devicetree/bindings/trivial-devices.yaml | 6 -
2 files changed, 148 insertions(+), 6 deletions(-)
create mode 100644 Documentation/devicetree/bindings/hwmon/pmbus/isil,isl68137.yaml
diff --git a/Documentation/devicetree/bindings/hwmon/pmbus/isil,isl68137.yaml b/Documentation/devicetree/bindings/hwmon/pmbus/isil,isl68137.yaml
new file mode 100644
index 000000000000..bac5f8e352aa
--- /dev/null
+++ b/Documentation/devicetree/bindings/hwmon/pmbus/isil,isl68137.yaml
@@ -0,0 +1,148 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+
+$id: http://devicetree.org/schemas/hwmon/pmbus/isil,isl68137.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Renesas Digital Multiphase Voltage Regulators with PMBus
+
+maintainers:
+ - Grant Peltier <grant.peltier.jg@renesas.com>
+
+description: |
+ Renesas digital multiphase voltage regulators with PMBus.
+ https://www.renesas.com/en/products/power-management/multiphase-power/multiphase-dcdc-switching-controllers
+
+properties:
+ compatible:
+ enum:
+ - isil,isl68137
+ - renesas,isl68220
+ - renesas,isl68221
+ - renesas,isl68222
+ - renesas,isl68223
+ - renesas,isl68224
+ - renesas,isl68225
+ - renesas,isl68226
+ - renesas,isl68227
+ - renesas,isl68229
+ - renesas,isl68233
+ - renesas,isl68239
+ - renesas,isl69222
+ - renesas,isl69223
+ - renesas,isl69224
+ - renesas,isl69225
+ - renesas,isl69227
+ - renesas,isl69228
+ - renesas,isl69234
+ - renesas,isl69236
+ - renesas,isl69239
+ - renesas,isl69242
+ - renesas,isl69243
+ - renesas,isl69247
+ - renesas,isl69248
+ - renesas,isl69254
+ - renesas,isl69255
+ - renesas,isl69256
+ - renesas,isl69259
+ - isil,isl69260
+ - renesas,isl69268
+ - isil,isl69269
+ - renesas,isl69298
+ - renesas,raa228000
+ - renesas,raa228004
+ - renesas,raa228006
+ - renesas,raa228228
+ - renesas,raa229001
+ - renesas,raa229004
+
+ reg:
+ maxItems: 1
+
+ '#address-cells':
+ const: 1
+
+ '#size-cells':
+ const: 0
+
+patternProperties:
+ "^channel@([0-3])$":
+ type: object
+ description:
+ Container for properties specific to a particular channel (rail).
+
+ properties:
+ reg:
+ description: The channel (rail) index.
+ items:
+ minimum: 0
+ maximum: 3
+
+ vout-voltage-divider:
+ description: |
+ Resistances of a voltage divider placed between Vout and the voltage
+ sense (Vsense) pin for the given channel (rail). It has two numbers
+ representing the resistances of the voltage divider provided as
+ <Rout Rtotal> which yields an adjusted Vout as
+ Vout_adj = Vout * Rtotal / Rout given the original Vout as reported
+ by the Vsense pin. Given a circuit configuration similar to the one
+ below, Rtotal = R1 + Rout.
+
+ Vout ----.
+ |
+ .-----.
+ | R1 |
+ '-----'
+ |
+ +---- Vsense
+ |
+ .-----.
+ | Rout|
+ '-----'
+ |
+ GND
+
+ $ref: /schemas/types.yaml#/definitions/uint32-array
+ minItems: 2
+ maxItems: 2
+
+ required:
+ - reg
+
+ additionalProperties: false
+
+required:
+ - compatible
+ - reg
+
+additionalProperties: false
+
+examples:
+ - |
+ i2c {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ isl68239@60 {
+ compatible = "isil,isl68137";
+ reg = <0x60>;
+ };
+ };
+ - |
+ i2c {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ isl68239@60 {
+ compatible = "renesas,isl68239";
+ reg = <0x60>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ channel@0 {
+ reg = <0>;
+ vout-voltage-divider = <1000 2000>; // Reported Vout/Pout would be scaled by 2
+ };
+ };
+ };
diff --git a/Documentation/devicetree/bindings/trivial-devices.yaml b/Documentation/devicetree/bindings/trivial-devices.yaml
index 0108d7507215..5afe09026938 100644
--- a/Documentation/devicetree/bindings/trivial-devices.yaml
+++ b/Documentation/devicetree/bindings/trivial-devices.yaml
@@ -155,12 +155,6 @@ properties:
- isil,isl29028
# Intersil ISL29030 Ambient Light and Proximity Sensor
- isil,isl29030
- # Intersil ISL68137 Digital Output Configurable PWM Controller
- - isil,isl68137
- # Intersil ISL69260 PMBus Voltage Regulator
- - isil,isl69260
- # Intersil ISL69269 PMBus Voltage Regulator
- - isil,isl69269
# Intersil ISL76682 Ambient Light Sensor
- isil,isl76682
# JEDEC JESD300 (SPD5118) Hub and Serial Presence Detect
--
2.39.5
^ permalink raw reply related [flat|nested] 6+ messages in thread