Re: [PATCH v3 1/3] dt-bindings: hwmon: Add Infineon TDA38640
From: Guenter Roeck
Date: Tue Aug 08 2023 - 13:22:22 EST
On 8/8/23 04:46, Conor Dooley wrote:
On Wed, Aug 02, 2023 at 09:31:51PM +0200, Naresh Solanki wrote:
From: Patrick Rudolph <patrick.rudolph@xxxxxxxxxxxxx>
The TDA38640 chip has different output control mechanisms depending on
its mode of operation. When the chip is in SVID mode, only
hardware-based output control is supported via ENABLE pin. However, when
it operates in PMBus mode, software control works perfectly.
To enable software control as a workaround in SVID mode, add the DT
property 'infineon,en-svid-control'. This property will enable the
workaround, which utilizes ENABLE pin polarity flipping for output when
the chip is in SVID mode.
Why do you need a custom property for this? How come it is not possible
to determine what bus you are on?
That is not the point. Yes, it can be detected if the control method is
PMBus or SVID. However, in SVID mode, SVID is supposed to control the
output, not PMBUs. This is bypassed by controlling the polarity of the
(physical) output enable signal. We do _not_ want this enabled automatically
in SVID mode. Its side effects on random boards using this chip are unknown.
Thus, this needs a property which specifically enables this functionality
for users who _really_ need to use it and (hopefully) know what they are
doing.
Guenter
Thanks,
Conor.
Signed-off-by: Patrick Rudolph <patrick.rudolph@xxxxxxxxxxxxx>
Signed-off-by: Naresh Solanki <Naresh.Solanki@xxxxxxxxxxxxx>
---
.../hwmon/pmbus/infineon,tda38640.yaml | 51 +++++++++++++++++++
.../devicetree/bindings/trivial-devices.yaml | 2 -
2 files changed, 51 insertions(+), 2 deletions(-)
create mode 100644 Documentation/devicetree/bindings/hwmon/pmbus/infineon,tda38640.yaml
diff --git a/Documentation/devicetree/bindings/hwmon/pmbus/infineon,tda38640.yaml b/Documentation/devicetree/bindings/hwmon/pmbus/infineon,tda38640.yaml
new file mode 100644
index 000000000000..c5924ddf1b47
--- /dev/null
+++ b/Documentation/devicetree/bindings/hwmon/pmbus/infineon,tda38640.yaml
@@ -0,0 +1,51 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+
+$id: http://devicetree.org/schemas/hwmon/pmbus/infineon,tda38640.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Infineon TDA38640 Synchronous Buck Regulator with SVID and I2C
+
+maintainers:
+ - Naresh Solanki <naresh.solanki@xxxxxxxxxxxxx>
+
+description: |
+ The Infineon TDA38640 is a 40A Single-voltage Synchronous Buck
+ Regulator with SVID and I2C designed for Industrial use.
+
+ Datasheet: https://www.infineon.com/dgdl/Infineon-TDA38640-0000-DataSheet-v02_04-EN.pdf?fileId=8ac78c8c80027ecd018042f2337f00c9
+
+properties:
+ compatible:
+ enum:
+ - infineon,tda38640
+
+ reg:
+ maxItems: 1
+
+ infineon,en-svid-control:
+ description: |
+ When enabled, it allows the chip to utilize workaround for
+ software control of output when operating in SVID mode where
+ hardware-based output control is the default behavior.
+ type: boolean
+
+required:
+ - compatible
+ - reg
+
+additionalProperties: false
+
+examples:
+ - |
+ i2c {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ tda38640@40 {
+ compatible = "infineon,tda38640";
+ reg = <0x40>;
+ };
+ };
+
diff --git a/Documentation/devicetree/bindings/trivial-devices.yaml b/Documentation/devicetree/bindings/trivial-devices.yaml
index 40bc475ee7e1..86c7d34f63bf 100644
--- a/Documentation/devicetree/bindings/trivial-devices.yaml
+++ b/Documentation/devicetree/bindings/trivial-devices.yaml
@@ -151,8 +151,6 @@ properties:
- infineon,slb9645tt
# Infineon SLB9673 I2C TPM 2.0
- infineon,slb9673
- # Infineon TDA38640 Voltage Regulator
- - infineon,tda38640
# Infineon TLV493D-A1B6 I2C 3D Magnetic Sensor
- infineon,tlv493d-a1b6
# Infineon Multi-phase Digital VR Controller xdpe11280
base-commit: cb7022b8976e3c4d12cea2e7bb820a2944e2fd7b
--
2.41.0