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* [PATCH RESEND v10 0/3] Support pwm/tach driver for aspeed ast26xx
@ 2023-11-07 10:50 ` Billy Tsai
  0 siblings, 0 replies; 31+ messages in thread
From: Billy Tsai @ 2023-11-07 10:50 UTC (permalink / raw)
  To: jdelvare, linux, robh+dt, krzysztof.kozlowski+dt, joel, andrew,
	corbet, thierry.reding, u.kleine-koenig, p.zabel, billy_tsai,
	naresh.solanki, linux-hwmon, devicetree, linux-arm-kernel,
	linux-aspeed, linux-kernel, linux-doc, linux-pwm, BMC-SW,
	patrick

Unlike the old design that the register setting of the TACH should based
on the configure of the PWM. In ast26xx, the dependency between pwm and
tach controller is eliminated and becomes a separate hardware block. One
is used to provide pwm output and another is used to monitor the frequency
of the input. This driver implements them by exposing two kernel
subsystems: PWM and HWMON. The PWM subsystem can be utilized alongside
existing drivers for controlling elements such as fans (pwm-fan.c),
beepers (pwm-beeper.c) and so on. Through the HWMON subsystem, the driver
provides sysfs interfaces for fan.

Changes since v9:
Change the type of fan-driving-mode to string
Fix some typos and formatting issues.

Changes since v8:
Fix the fail of fan div register setting. (FIELD_GET -> FIELD_PREP)
Change the type of tach-ch from uint32_t to uint8-array
Add additional properties and apply constraints to certain properties.

Changes since v7:
Cherry-pick the fan-common.yaml and add the following properties:
- min-rpm
- div
- mode
- tach-ch
Fix the warning which is reported by the kernel test robot.

Changes since v6:
Consolidate the PWM and TACH functionalities into a unified driver.

Changes since v5:
- pwm/tach:
  - Remove the utilization of common resources from the parent node.
  - Change the concept to 16 PWM/TACH controllers, each with one channel,
  instead of 1 PWM/TACH controller with 16 channels.
- dt-binding:
  - Eliminate the usage of simple-mfd.

Changes since v4:
- pwm:
  - Fix the return type of get_status function.
- tach:
  - read clk source once and re-use it
  - Remove the constants variables
  - Allocate tach_channel as array
  - Use dev->parent
- dt-binding:
  - Fix the order of the patches
  - Add example and description for tach child node
  - Remove pwm extension property

Changes since v3:
- pwm:
  - Remove unnecessary include header
  - Fix warning Prefer "GPL" over "GPL v2"
- tach:
  - Remove the paremeter min_rpm and max_rpm and return the tach value 
  directly without any polling or delay.
  - Fix warning Prefer "GPL" over "GPL v2"
- dt-binding:
  - Replace underscore in node names with dashes
  - Split per subsystem

Changes since v2:
- pwm:
  - Use devm_* api to simplify the error cleanup
  - Fix the multi-line alignment problem
- tach:
  - Add tach-aspeed-ast2600 to index.rst
  - Fix the multi-line alignment problem
  - Remove the tach enable/disable when read the rpm
  - Fix some coding format issue

Changes since v1:
- tach:
  - Add the document tach-aspeed-ast2600.rst
  - Use devm_* api to simplify the error cleanup.
  - Change hwmon register api to devm_hwmon_device_register_with_info

Billy Tsai (2):
  dt-bindings: hwmon: Support Aspeed g6 PWM TACH Control
  hwmon: (aspeed-g6-pwm-tacho): Support for ASPEED g6 PWM/Fan tach

Naresh Solanki (1):
  dt-bindings: hwmon: fan: Add fan binding to schema

 .../bindings/hwmon/aspeed,g6-pwm-tach.yaml    |  69 +++
 .../devicetree/bindings/hwmon/fan-common.yaml |  78 +++
 Documentation/hwmon/aspeed-g6-pwm-tach.rst    |  26 +
 Documentation/hwmon/index.rst                 |   1 +
 drivers/hwmon/Kconfig                         |  11 +
 drivers/hwmon/Makefile                        |   1 +
 drivers/hwmon/aspeed-g6-pwm-tach.c            | 539 ++++++++++++++++++
 7 files changed, 725 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/hwmon/aspeed,g6-pwm-tach.yaml
 create mode 100644 Documentation/devicetree/bindings/hwmon/fan-common.yaml
 create mode 100644 Documentation/hwmon/aspeed-g6-pwm-tach.rst
 create mode 100644 drivers/hwmon/aspeed-g6-pwm-tach.c

-- 
2.25.1


^ permalink raw reply	[flat|nested] 31+ messages in thread
* [PATCH RESEND v10 0/3] Support pwm/tach driver for aspeed ast26xx
@ 2023-11-07 10:50 ` Billy Tsai
  0 siblings, 0 replies; 31+ messages in thread
From: Billy Tsai @ 2023-11-07 10:50 UTC (permalink / raw)
  To: jdelvare, linux, robh+dt, krzysztof.kozlowski+dt, joel, andrew,
	corbet, thierry.reding, u.kleine-koenig, p.zabel, billy_tsai,
	naresh.solanki, linux-hwmon, devicetree, linux-arm-kernel,
	linux-aspeed, linux-kernel, linux-doc, linux-pwm, BMC-SW,
	patrick

Unlike the old design that the register setting of the TACH should based
on the configure of the PWM. In ast26xx, the dependency between pwm and
tach controller is eliminated and becomes a separate hardware block. One
is used to provide pwm output and another is used to monitor the frequency
of the input. This driver implements them by exposing two kernel
subsystems: PWM and HWMON. The PWM subsystem can be utilized alongside
existing drivers for controlling elements such as fans (pwm-fan.c),
beepers (pwm-beeper.c) and so on. Through the HWMON subsystem, the driver
provides sysfs interfaces for fan.

Changes since v9:
Change the type of fan-driving-mode to string
Fix some typos and formatting issues.

Changes since v8:
Fix the fail of fan div register setting. (FIELD_GET -> FIELD_PREP)
Change the type of tach-ch from uint32_t to uint8-array
Add additional properties and apply constraints to certain properties.

Changes since v7:
Cherry-pick the fan-common.yaml and add the following properties:
- min-rpm
- div
- mode
- tach-ch
Fix the warning which is reported by the kernel test robot.

Changes since v6:
Consolidate the PWM and TACH functionalities into a unified driver.

Changes since v5:
- pwm/tach:
  - Remove the utilization of common resources from the parent node.
  - Change the concept to 16 PWM/TACH controllers, each with one channel,
  instead of 1 PWM/TACH controller with 16 channels.
- dt-binding:
  - Eliminate the usage of simple-mfd.

Changes since v4:
- pwm:
  - Fix the return type of get_status function.
- tach:
  - read clk source once and re-use it
  - Remove the constants variables
  - Allocate tach_channel as array
  - Use dev->parent
- dt-binding:
  - Fix the order of the patches
  - Add example and description for tach child node
  - Remove pwm extension property

Changes since v3:
- pwm:
  - Remove unnecessary include header
  - Fix warning Prefer "GPL" over "GPL v2"
- tach:
  - Remove the paremeter min_rpm and max_rpm and return the tach value 
  directly without any polling or delay.
  - Fix warning Prefer "GPL" over "GPL v2"
- dt-binding:
  - Replace underscore in node names with dashes
  - Split per subsystem

Changes since v2:
- pwm:
  - Use devm_* api to simplify the error cleanup
  - Fix the multi-line alignment problem
- tach:
  - Add tach-aspeed-ast2600 to index.rst
  - Fix the multi-line alignment problem
  - Remove the tach enable/disable when read the rpm
  - Fix some coding format issue

Changes since v1:
- tach:
  - Add the document tach-aspeed-ast2600.rst
  - Use devm_* api to simplify the error cleanup.
  - Change hwmon register api to devm_hwmon_device_register_with_info

Billy Tsai (2):
  dt-bindings: hwmon: Support Aspeed g6 PWM TACH Control
  hwmon: (aspeed-g6-pwm-tacho): Support for ASPEED g6 PWM/Fan tach

Naresh Solanki (1):
  dt-bindings: hwmon: fan: Add fan binding to schema

 .../bindings/hwmon/aspeed,g6-pwm-tach.yaml    |  69 +++
 .../devicetree/bindings/hwmon/fan-common.yaml |  78 +++
 Documentation/hwmon/aspeed-g6-pwm-tach.rst    |  26 +
 Documentation/hwmon/index.rst                 |   1 +
 drivers/hwmon/Kconfig                         |  11 +
 drivers/hwmon/Makefile                        |   1 +
 drivers/hwmon/aspeed-g6-pwm-tach.c            | 539 ++++++++++++++++++
 7 files changed, 725 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/hwmon/aspeed,g6-pwm-tach.yaml
 create mode 100644 Documentation/devicetree/bindings/hwmon/fan-common.yaml
 create mode 100644 Documentation/hwmon/aspeed-g6-pwm-tach.rst
 create mode 100644 drivers/hwmon/aspeed-g6-pwm-tach.c

-- 
2.25.1


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

^ permalink raw reply	[flat|nested] 31+ messages in thread
* [PATCH RESEND v10 1/3] dt-bindings: hwmon: fan: Add fan binding to schema
  2023-11-07 10:50 ` Billy Tsai
@ 2023-11-07 10:50   ` Billy Tsai
  -1 siblings, 0 replies; 31+ messages in thread
From: Billy Tsai @ 2023-11-07 10:50 UTC (permalink / raw)
  To: jdelvare, linux, robh+dt, krzysztof.kozlowski+dt, joel, andrew,
	corbet, thierry.reding, u.kleine-koenig, p.zabel, billy_tsai,
	naresh.solanki, linux-hwmon, devicetree, linux-arm-kernel,
	linux-aspeed, linux-kernel, linux-doc, linux-pwm, BMC-SW,
	patrick

From: Naresh Solanki <naresh.solanki@9elements.com>

Add common fan properties bindings to a schema.

Bindings for fan controllers can reference the common schema for the
fan

child nodes:

  patternProperties:
    "^fan@[0-2]":
      type: object
      $ref: fan-common.yaml#
      unevaluatedProperties: false

Signed-off-by: Naresh Solanki <naresh.solanki@9elements.com>
Signed-off-by: Billy Tsai <billy_tsai@aspeedtech.com>
---
 .../devicetree/bindings/hwmon/fan-common.yaml | 78 +++++++++++++++++++
 1 file changed, 78 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/hwmon/fan-common.yaml

diff --git a/Documentation/devicetree/bindings/hwmon/fan-common.yaml b/Documentation/devicetree/bindings/hwmon/fan-common.yaml
new file mode 100644
index 000000000000..be4ce3bd7f22
--- /dev/null
+++ b/Documentation/devicetree/bindings/hwmon/fan-common.yaml
@@ -0,0 +1,78 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/hwmon/fan-common.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Common Fan Properties
+
+maintainers:
+  - Naresh Solanki <naresh.solanki@9elements.com>
+  - Billy Tsai <billy_tsai@aspeedtech.com>
+
+properties:
+  max-rpm:
+    description:
+      Max RPM supported by fan.
+    $ref: /schemas/types.yaml#/definitions/uint32
+    maximum: 100000
+
+  min-rpm:
+    description:
+      Min RPM supported by fan.
+    $ref: /schemas/types.yaml#/definitions/uint32
+    maximum: 1000
+
+  pulses-per-revolution:
+    description:
+      The number of pulse from fan sensor per revolution.
+    $ref: /schemas/types.yaml#/definitions/uint32
+    maximum: 4
+
+  tach-div:
+    description:
+      Divisor for the tach sampling clock, which determines the sensitivity of the tach pin.
+    $ref: /schemas/types.yaml#/definitions/uint32
+
+  target-rpm:
+    description:
+      The default desired fan speed in RPM.
+    $ref: /schemas/types.yaml#/definitions/uint32
+
+  fan-driving-mode:
+    description:
+      Select the driving mode of the fan.(DC, PWM and so on)
+    $ref: /schemas/types.yaml#/definitions/string
+
+  pwms:
+    description:
+      PWM provider.
+    maxItems: 1
+
+  "#cooling-cells":
+    const: 2
+
+  cooling-levels:
+    description:
+      The control value which correspond to thermal cooling states.
+    $ref: /schemas/types.yaml#/definitions/uint32-array
+
+  tach-ch:
+    description:
+      The tach channel used for the fan.
+    $ref: /schemas/types.yaml#/definitions/uint8-array
+
+  label:
+    description:
+      Optional fan label
+
+  fan-supply:
+    description:
+      Power supply for fan.
+
+  reg:
+    maxItems: 1
+
+additionalProperties: true
+
+...
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 31+ messages in thread
* [PATCH RESEND v10 1/3] dt-bindings: hwmon: fan: Add fan binding to schema
@ 2023-11-07 10:50   ` Billy Tsai
  0 siblings, 0 replies; 31+ messages in thread
From: Billy Tsai @ 2023-11-07 10:50 UTC (permalink / raw)
  To: jdelvare, linux, robh+dt, krzysztof.kozlowski+dt, joel, andrew,
	corbet, thierry.reding, u.kleine-koenig, p.zabel, billy_tsai,
	naresh.solanki, linux-hwmon, devicetree, linux-arm-kernel,
	linux-aspeed, linux-kernel, linux-doc, linux-pwm, BMC-SW,
	patrick

From: Naresh Solanki <naresh.solanki@9elements.com>

Add common fan properties bindings to a schema.

Bindings for fan controllers can reference the common schema for the
fan

child nodes:

  patternProperties:
    "^fan@[0-2]":
      type: object
      $ref: fan-common.yaml#
      unevaluatedProperties: false

Signed-off-by: Naresh Solanki <naresh.solanki@9elements.com>
Signed-off-by: Billy Tsai <billy_tsai@aspeedtech.com>
---
 .../devicetree/bindings/hwmon/fan-common.yaml | 78 +++++++++++++++++++
 1 file changed, 78 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/hwmon/fan-common.yaml

diff --git a/Documentation/devicetree/bindings/hwmon/fan-common.yaml b/Documentation/devicetree/bindings/hwmon/fan-common.yaml
new file mode 100644
index 000000000000..be4ce3bd7f22
--- /dev/null
+++ b/Documentation/devicetree/bindings/hwmon/fan-common.yaml
@@ -0,0 +1,78 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/hwmon/fan-common.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Common Fan Properties
+
+maintainers:
+  - Naresh Solanki <naresh.solanki@9elements.com>
+  - Billy Tsai <billy_tsai@aspeedtech.com>
+
+properties:
+  max-rpm:
+    description:
+      Max RPM supported by fan.
+    $ref: /schemas/types.yaml#/definitions/uint32
+    maximum: 100000
+
+  min-rpm:
+    description:
+      Min RPM supported by fan.
+    $ref: /schemas/types.yaml#/definitions/uint32
+    maximum: 1000
+
+  pulses-per-revolution:
+    description:
+      The number of pulse from fan sensor per revolution.
+    $ref: /schemas/types.yaml#/definitions/uint32
+    maximum: 4
+
+  tach-div:
+    description:
+      Divisor for the tach sampling clock, which determines the sensitivity of the tach pin.
+    $ref: /schemas/types.yaml#/definitions/uint32
+
+  target-rpm:
+    description:
+      The default desired fan speed in RPM.
+    $ref: /schemas/types.yaml#/definitions/uint32
+
+  fan-driving-mode:
+    description:
+      Select the driving mode of the fan.(DC, PWM and so on)
+    $ref: /schemas/types.yaml#/definitions/string
+
+  pwms:
+    description:
+      PWM provider.
+    maxItems: 1
+
+  "#cooling-cells":
+    const: 2
+
+  cooling-levels:
+    description:
+      The control value which correspond to thermal cooling states.
+    $ref: /schemas/types.yaml#/definitions/uint32-array
+
+  tach-ch:
+    description:
+      The tach channel used for the fan.
+    $ref: /schemas/types.yaml#/definitions/uint8-array
+
+  label:
+    description:
+      Optional fan label
+
+  fan-supply:
+    description:
+      Power supply for fan.
+
+  reg:
+    maxItems: 1
+
+additionalProperties: true
+
+...
-- 
2.25.1


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

^ permalink raw reply related	[flat|nested] 31+ messages in thread
* [PATCH RESEND v10 2/3] dt-bindings: hwmon: Support Aspeed g6 PWM TACH Control
  2023-11-07 10:50 ` Billy Tsai
@ 2023-11-07 10:50   ` Billy Tsai
  -1 siblings, 0 replies; 31+ messages in thread
From: Billy Tsai @ 2023-11-07 10:50 UTC (permalink / raw)
  To: jdelvare, linux, robh+dt, krzysztof.kozlowski+dt, joel, andrew,
	corbet, thierry.reding, u.kleine-koenig, p.zabel, billy_tsai,
	naresh.solanki, linux-hwmon, devicetree, linux-arm-kernel,
	linux-aspeed, linux-kernel, linux-doc, linux-pwm, BMC-SW,
	patrick

Document the compatible for aspeed,ast2600-pwm-tach device, which can
support up to 16 PWM outputs and 16 fan tach input.

Signed-off-by: Billy Tsai <billy_tsai@aspeedtech.com>
---
 .../bindings/hwmon/aspeed,g6-pwm-tach.yaml    | 69 +++++++++++++++++++
 1 file changed, 69 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/hwmon/aspeed,g6-pwm-tach.yaml

diff --git a/Documentation/devicetree/bindings/hwmon/aspeed,g6-pwm-tach.yaml b/Documentation/devicetree/bindings/hwmon/aspeed,g6-pwm-tach.yaml
new file mode 100644
index 000000000000..c615fb10705c
--- /dev/null
+++ b/Documentation/devicetree/bindings/hwmon/aspeed,g6-pwm-tach.yaml
@@ -0,0 +1,69 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+# Copyright (C) 2023 Aspeed, Inc.
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/hwmon/aspeed,g6-pwm-tach.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: ASPEED G6 PWM and Fan Tach controller
+
+maintainers:
+  - Billy Tsai <billy_tsai@aspeedtech.com>
+
+description: |
+  The ASPEED PWM controller can support up to 16 PWM outputs.
+  The ASPEED Fan Tacho controller can support up to 16 fan tach input.
+  They are independent hardware blocks, which are different from the
+  previous version of the ASPEED chip.
+
+properties:
+  compatible:
+    enum:
+      - aspeed,ast2600-pwm-tach
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  resets:
+    maxItems: 1
+
+  "#pwm-cells":
+    const: 3
+
+patternProperties:
+  "^fan-[0-9]+$":
+    $ref: fan-common.yaml#
+    unevaluatedProperties: false
+    required:
+      - tach-ch
+
+required:
+  - reg
+  - clocks
+  - resets
+  - "#pwm-cells"
+  - compatible
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/clock/aspeed-clock.h>
+    pwm_tach: pwm-tach-controller@1e610000 {
+      compatible = "aspeed,ast2600-pwm-tach";
+      reg = <0x1e610000 0x100>;
+      clocks = <&syscon ASPEED_CLK_AHB>;
+      resets = <&syscon ASPEED_RESET_PWM>;
+      #pwm-cells = <3>;
+
+      fan-0 {
+        tach-ch = /bits/ 8 <0x0>;
+      };
+
+      fan-1 {
+        tach-ch = /bits/ 8 <0x1 0x2>;
+      };
+    };
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 31+ messages in thread
* [PATCH RESEND v10 2/3] dt-bindings: hwmon: Support Aspeed g6 PWM TACH Control
@ 2023-11-07 10:50   ` Billy Tsai
  0 siblings, 0 replies; 31+ messages in thread
From: Billy Tsai @ 2023-11-07 10:50 UTC (permalink / raw)
  To: jdelvare, linux, robh+dt, krzysztof.kozlowski+dt, joel, andrew,
	corbet, thierry.reding, u.kleine-koenig, p.zabel, billy_tsai,
	naresh.solanki, linux-hwmon, devicetree, linux-arm-kernel,
	linux-aspeed, linux-kernel, linux-doc, linux-pwm, BMC-SW,
	patrick

Document the compatible for aspeed,ast2600-pwm-tach device, which can
support up to 16 PWM outputs and 16 fan tach input.

Signed-off-by: Billy Tsai <billy_tsai@aspeedtech.com>
---
 .../bindings/hwmon/aspeed,g6-pwm-tach.yaml    | 69 +++++++++++++++++++
 1 file changed, 69 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/hwmon/aspeed,g6-pwm-tach.yaml

diff --git a/Documentation/devicetree/bindings/hwmon/aspeed,g6-pwm-tach.yaml b/Documentation/devicetree/bindings/hwmon/aspeed,g6-pwm-tach.yaml
new file mode 100644
index 000000000000..c615fb10705c
--- /dev/null
+++ b/Documentation/devicetree/bindings/hwmon/aspeed,g6-pwm-tach.yaml
@@ -0,0 +1,69 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+# Copyright (C) 2023 Aspeed, Inc.
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/hwmon/aspeed,g6-pwm-tach.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: ASPEED G6 PWM and Fan Tach controller
+
+maintainers:
+  - Billy Tsai <billy_tsai@aspeedtech.com>
+
+description: |
+  The ASPEED PWM controller can support up to 16 PWM outputs.
+  The ASPEED Fan Tacho controller can support up to 16 fan tach input.
+  They are independent hardware blocks, which are different from the
+  previous version of the ASPEED chip.
+
+properties:
+  compatible:
+    enum:
+      - aspeed,ast2600-pwm-tach
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  resets:
+    maxItems: 1
+
+  "#pwm-cells":
+    const: 3
+
+patternProperties:
+  "^fan-[0-9]+$":
+    $ref: fan-common.yaml#
+    unevaluatedProperties: false
+    required:
+      - tach-ch
+
+required:
+  - reg
+  - clocks
+  - resets
+  - "#pwm-cells"
+  - compatible
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/clock/aspeed-clock.h>
+    pwm_tach: pwm-tach-controller@1e610000 {
+      compatible = "aspeed,ast2600-pwm-tach";
+      reg = <0x1e610000 0x100>;
+      clocks = <&syscon ASPEED_CLK_AHB>;
+      resets = <&syscon ASPEED_RESET_PWM>;
+      #pwm-cells = <3>;
+
+      fan-0 {
+        tach-ch = /bits/ 8 <0x0>;
+      };
+
+      fan-1 {
+        tach-ch = /bits/ 8 <0x1 0x2>;
+      };
+    };
-- 
2.25.1


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

^ permalink raw reply related	[flat|nested] 31+ messages in thread
* [PATCH RESEND v10 3/3] hwmon: (aspeed-g6-pwm-tacho): Support for ASPEED g6 PWM/Fan tach
  2023-11-07 10:50 ` Billy Tsai
@ 2023-11-07 10:50   ` Billy Tsai
  -1 siblings, 0 replies; 31+ messages in thread
From: Billy Tsai @ 2023-11-07 10:50 UTC (permalink / raw)
  To: jdelvare, linux, robh+dt, krzysztof.kozlowski+dt, joel, andrew,
	corbet, thierry.reding, u.kleine-koenig, p.zabel, billy_tsai,
	naresh.solanki, linux-hwmon, devicetree, linux-arm-kernel,
	linux-aspeed, linux-kernel, linux-doc, linux-pwm, BMC-SW,
	patrick

The driver support two functions: PWM and Tachometer. The PWM feature can
handle up to 16 output ports, while the Tachometer can monitor to up to 16
input ports as well. This driver implements them by exposing two kernel
subsystems: PWM and HWMON. The PWM subsystem can be utilized alongside
existing drivers for controlling elements such as fans (pwm-fan.c),
beepers (pwm-beeper.c) and so on. Through the HWMON subsystem, the driver
provides sysfs interfaces for fan.

Signed-off-by: Billy Tsai <billy_tsai@aspeedtech.com>
---
 Documentation/hwmon/aspeed-g6-pwm-tach.rst |  26 +
 Documentation/hwmon/index.rst              |   1 +
 drivers/hwmon/Kconfig                      |  11 +
 drivers/hwmon/Makefile                     |   1 +
 drivers/hwmon/aspeed-g6-pwm-tach.c         | 539 +++++++++++++++++++++
 5 files changed, 578 insertions(+)
 create mode 100644 Documentation/hwmon/aspeed-g6-pwm-tach.rst
 create mode 100644 drivers/hwmon/aspeed-g6-pwm-tach.c

diff --git a/Documentation/hwmon/aspeed-g6-pwm-tach.rst b/Documentation/hwmon/aspeed-g6-pwm-tach.rst
new file mode 100644
index 000000000000..17398fe397fe
--- /dev/null
+++ b/Documentation/hwmon/aspeed-g6-pwm-tach.rst
@@ -0,0 +1,26 @@
+.. SPDX-License-Identifier: GPL-2.0-or-later
+
+Kernel driver aspeed-g6-pwm-tach
+=================================
+
+Supported chips:
+	ASPEED AST2600
+
+Authors:
+	<billy_tsai@aspeedtech.com>
+
+Description:
+------------
+This driver implements support for ASPEED AST2600 Fan Tacho controller.
+The controller supports up to 16 tachometer inputs.
+
+The driver provides the following sensor accesses in sysfs:
+
+=============== ======= ======================================================
+fanX_input	ro	provide current fan rotation value in RPM as reported
+			by the fan to the device.
+fanX_div	rw	Fan divisor: Supported value are power of 4 (1, 4, 16
+                        64, ... 4194304)
+                        The larger divisor, the less rpm accuracy and the less
+                        affected by fan signal glitch.
+=============== ======= ======================================================
diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst
index 042e1cf9501b..75b869ff6c53 100644
--- a/Documentation/hwmon/index.rst
+++ b/Documentation/hwmon/index.rst
@@ -44,6 +44,7 @@ Hardware Monitoring Kernel Drivers
    aquacomputer_d5next
    asb100
    asc7621
+   aspeed-g6-pwm-tach
    aspeed-pwm-tacho
    asus_ec_sensors
    asus_wmi_sensors
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 307477b8a371..75fbea7e81e2 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -412,6 +412,17 @@ config SENSORS_ASPEED
 	  This driver can also be built as a module. If so, the module
 	  will be called aspeed_pwm_tacho.
 
+config SENSORS_ASPEED_G6
+	tristate "ASPEED g6 PWM and Fan tach driver"
+	depends on ARCH_ASPEED || COMPILE_TEST
+	depends on PWM
+	help
+	  This driver provides support for ASPEED G6 PWM and Fan Tach
+	  controllers.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called aspeed_pwm_tacho.
+
 config SENSORS_ATXP1
 	tristate "Attansic ATXP1 VID controller"
 	depends on I2C
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index 3f4b0fda0998..51de5c1d5f1e 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -55,6 +55,7 @@ obj-$(CONFIG_SENSORS_ARM_SCPI)	+= scpi-hwmon.o
 obj-$(CONFIG_SENSORS_AS370)	+= as370-hwmon.o
 obj-$(CONFIG_SENSORS_ASC7621)	+= asc7621.o
 obj-$(CONFIG_SENSORS_ASPEED)	+= aspeed-pwm-tacho.o
+obj-$(CONFIG_SENSORS_ASPEED_G6) += aspeed-g6-pwm-tach.o
 obj-$(CONFIG_SENSORS_ATXP1)	+= atxp1.o
 obj-$(CONFIG_SENSORS_AXI_FAN_CONTROL) += axi-fan-control.o
 obj-$(CONFIG_SENSORS_BT1_PVT)	+= bt1-pvt.o
diff --git a/drivers/hwmon/aspeed-g6-pwm-tach.c b/drivers/hwmon/aspeed-g6-pwm-tach.c
new file mode 100644
index 000000000000..504574e8940c
--- /dev/null
+++ b/drivers/hwmon/aspeed-g6-pwm-tach.c
@@ -0,0 +1,539 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2021 Aspeed Technology Inc.
+ *
+ * PWM/TACH controller driver for Aspeed ast2600 SoCs.
+ * This drivers doesn't support earlier version of the IP.
+ *
+ * The hardware operates in time quantities of length
+ * Q := (DIV_L + 1) << DIV_H / input-clk
+ * The length of a PWM period is (DUTY_CYCLE_PERIOD + 1) * Q.
+ * The maximal value for DUTY_CYCLE_PERIOD is used here to provide
+ * a fine grained selection for the duty cycle.
+ *
+ * This driver uses DUTY_CYCLE_RISING_POINT = 0, so from the start of a
+ * period the output is active until DUTY_CYCLE_FALLING_POINT * Q. Note
+ * that if DUTY_CYCLE_RISING_POINT = DUTY_CYCLE_FALLING_POINT the output is
+ * always active.
+ *
+ * Register usage:
+ * PIN_ENABLE: When it is unset the pwm controller will emit inactive level to the external.
+ * Use to determine whether the PWM channel is enabled or disabled
+ * CLK_ENABLE: When it is unset the pwm controller will assert the duty counter reset and
+ * emit inactive level to the PIN_ENABLE mux after that the driver can still change the pwm period
+ * and duty and the value will apply when CLK_ENABLE be set again.
+ * Use to determine whether duty_cycle bigger than 0.
+ * PWM_ASPEED_CTRL_INVERSE: When it is toggled the output value will inverse immediately.
+ * PWM_ASPEED_DUTY_CYCLE_FALLING_POINT/PWM_ASPEED_DUTY_CYCLE_RISING_POINT: When these two
+ * values are equal it means the duty cycle = 100%.
+ *
+ * The glitch may generate at:
+ * - Enabled changing when the duty_cycle bigger than 0% and less than 100%.
+ * - Polarity changing when the duty_cycle bigger than 0% and less than 100%.
+ *
+ * Limitations:
+ * - When changing both duty cycle and period, we cannot prevent in
+ *   software that the output might produce a period with mixed
+ *   settings.
+ * - Disabling the PWM doesn't complete the current period.
+ *
+ * Improvements:
+ * - When only changing one of duty cycle or period, our pwm controller will not
+ *   generate the glitch, the configure will change at next cycle of pwm.
+ *   This improvement can disable/enable through PWM_ASPEED_CTRL_DUTY_SYNC_DISABLE.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/errno.h>
+#include <linux/hwmon.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/math64.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+#include <linux/reset.h>
+#include <linux/sysfs.h>
+
+/* The channel number of Aspeed pwm controller */
+#define PWM_ASPEED_NR_PWMS			16
+/* PWM Control Register */
+#define PWM_ASPEED_CTRL(ch)			((ch) * 0x10 + 0x00)
+#define PWM_ASPEED_CTRL_LOAD_SEL_RISING_AS_WDT	BIT(19)
+#define PWM_ASPEED_CTRL_DUTY_LOAD_AS_WDT_ENABLE	BIT(18)
+#define PWM_ASPEED_CTRL_DUTY_SYNC_DISABLE	BIT(17)
+#define PWM_ASPEED_CTRL_CLK_ENABLE		BIT(16)
+#define PWM_ASPEED_CTRL_LEVEL_OUTPUT		BIT(15)
+#define PWM_ASPEED_CTRL_INVERSE			BIT(14)
+#define PWM_ASPEED_CTRL_OPEN_DRAIN_ENABLE	BIT(13)
+#define PWM_ASPEED_CTRL_PIN_ENABLE		BIT(12)
+#define PWM_ASPEED_CTRL_CLK_DIV_H		GENMASK(11, 8)
+#define PWM_ASPEED_CTRL_CLK_DIV_L		GENMASK(7, 0)
+
+/* PWM Duty Cycle Register */
+#define PWM_ASPEED_DUTY_CYCLE(ch)		((ch) * 0x10 + 0x04)
+#define PWM_ASPEED_DUTY_CYCLE_PERIOD		GENMASK(31, 24)
+#define PWM_ASPEED_DUTY_CYCLE_POINT_AS_WDT	GENMASK(23, 16)
+#define PWM_ASPEED_DUTY_CYCLE_FALLING_POINT	GENMASK(15, 8)
+#define PWM_ASPEED_DUTY_CYCLE_RISING_POINT	GENMASK(7, 0)
+
+/* PWM fixed value */
+#define PWM_ASPEED_FIXED_PERIOD			FIELD_MAX(PWM_ASPEED_DUTY_CYCLE_PERIOD)
+
+/* The channel number of Aspeed tach controller */
+#define TACH_ASPEED_NR_TACHS		16
+/* TACH Control Register */
+#define TACH_ASPEED_CTRL(ch)		(((ch) * 0x10) + 0x08)
+#define TACH_ASPEED_IER			BIT(31)
+#define TACH_ASPEED_INVERS_LIMIT	BIT(30)
+#define TACH_ASPEED_LOOPBACK		BIT(29)
+#define TACH_ASPEED_ENABLE		BIT(28)
+#define TACH_ASPEED_DEBOUNCE_MASK	GENMASK(27, 26)
+#define TACH_ASPEED_DEBOUNCE_BIT	26
+#define TACH_ASPEED_IO_EDGE_MASK	GENMASK(25, 24)
+#define TACH_ASPEED_IO_EDGE_BIT		24
+#define TACH_ASPEED_CLK_DIV_T_MASK	GENMASK(23, 20)
+#define TACH_ASPEED_CLK_DIV_BIT		20
+#define TACH_ASPEED_THRESHOLD_MASK	GENMASK(19, 0)
+/* [27:26] */
+#define DEBOUNCE_3_CLK			0x00
+#define DEBOUNCE_2_CLK			0x01
+#define DEBOUNCE_1_CLK			0x02
+#define DEBOUNCE_0_CLK			0x03
+/* [25:24] */
+#define F2F_EDGES			0x00
+#define R2R_EDGES			0x01
+#define BOTH_EDGES			0x02
+/* [23:20] */
+/* divisor = 4 to the nth power, n = register value */
+#define DEFAULT_TACH_DIV		1024
+#define DIV_TO_REG(divisor)		(ilog2(divisor) >> 1)
+
+/* TACH Status Register */
+#define TACH_ASPEED_STS(ch)		(((ch) * 0x10) + 0x0C)
+
+/*PWM_TACH_STS */
+#define TACH_ASPEED_ISR			BIT(31)
+#define TACH_ASPEED_PWM_OUT		BIT(25)
+#define TACH_ASPEED_PWM_OEN		BIT(24)
+#define TACH_ASPEED_DEB_INPUT		BIT(23)
+#define TACH_ASPEED_RAW_INPUT		BIT(22)
+#define TACH_ASPEED_VALUE_UPDATE	BIT(21)
+#define TACH_ASPEED_FULL_MEASUREMENT	BIT(20)
+#define TACH_ASPEED_VALUE_MASK		GENMASK(19, 0)
+/**********************************************************
+ * Software setting
+ *********************************************************/
+#define DEFAULT_FAN_PULSE_PR		2
+
+struct aspeed_pwm_tach_data {
+	struct device *dev;
+	void __iomem *base;
+	struct clk *clk;
+	struct reset_control *reset;
+	unsigned long clk_rate;
+	struct pwm_chip chip;
+	bool tach_present[TACH_ASPEED_NR_TACHS];
+	u32 tach_divisor;
+};
+
+static inline struct aspeed_pwm_tach_data *
+aspeed_pwm_chip_to_data(struct pwm_chip *chip)
+{
+	return container_of(chip, struct aspeed_pwm_tach_data, chip);
+}
+
+static int aspeed_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
+				struct pwm_state *state)
+{
+	struct aspeed_pwm_tach_data *priv = aspeed_pwm_chip_to_data(chip);
+	u32 hwpwm = pwm->hwpwm;
+	bool polarity, pin_en, clk_en;
+	u32 duty_pt, val;
+	u64 div_h, div_l, duty_cycle_period, dividend;
+
+	val = readl(priv->base + PWM_ASPEED_CTRL(hwpwm));
+	polarity = FIELD_GET(PWM_ASPEED_CTRL_INVERSE, val);
+	pin_en = FIELD_GET(PWM_ASPEED_CTRL_PIN_ENABLE, val);
+	clk_en = FIELD_GET(PWM_ASPEED_CTRL_CLK_ENABLE, val);
+	div_h = FIELD_GET(PWM_ASPEED_CTRL_CLK_DIV_H, val);
+	div_l = FIELD_GET(PWM_ASPEED_CTRL_CLK_DIV_L, val);
+	val = readl(priv->base + PWM_ASPEED_DUTY_CYCLE(hwpwm));
+	duty_pt = FIELD_GET(PWM_ASPEED_DUTY_CYCLE_FALLING_POINT, val);
+	duty_cycle_period = FIELD_GET(PWM_ASPEED_DUTY_CYCLE_PERIOD, val);
+	/*
+	 * This multiplication doesn't overflow, the upper bound is
+	 * 1000000000 * 256 * 256 << 15 = 0x1dcd650000000000
+	 */
+	dividend = (u64)NSEC_PER_SEC * (div_l + 1) * (duty_cycle_period + 1)
+		       << div_h;
+	state->period = DIV_ROUND_UP_ULL(dividend, priv->clk_rate);
+
+	if (clk_en && duty_pt) {
+		dividend = (u64)NSEC_PER_SEC * (div_l + 1) * duty_pt
+				 << div_h;
+		state->duty_cycle = DIV_ROUND_UP_ULL(dividend, priv->clk_rate);
+	} else {
+		state->duty_cycle = clk_en ? state->period : 0;
+	}
+	state->polarity = polarity ? PWM_POLARITY_INVERSED : PWM_POLARITY_NORMAL;
+	state->enabled = pin_en;
+	return 0;
+}
+
+static int aspeed_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+			    const struct pwm_state *state)
+{
+	struct aspeed_pwm_tach_data *priv = aspeed_pwm_chip_to_data(chip);
+	u32 hwpwm = pwm->hwpwm, duty_pt, val;
+	u64 div_h, div_l, divisor, expect_period;
+	bool clk_en;
+
+	expect_period = div64_u64(ULLONG_MAX, (u64)priv->clk_rate);
+	expect_period = min(expect_period, state->period);
+	dev_dbg(chip->dev, "expect period: %lldns, duty_cycle: %lldns",
+		expect_period, state->duty_cycle);
+	/*
+	 * Pick the smallest value for div_h so that div_l can be the biggest
+	 * which results in a finer resolution near the target period value.
+	 */
+	divisor = (u64)NSEC_PER_SEC * (PWM_ASPEED_FIXED_PERIOD + 1) *
+		  (FIELD_MAX(PWM_ASPEED_CTRL_CLK_DIV_L) + 1);
+	div_h = order_base_2(DIV64_U64_ROUND_UP(priv->clk_rate * expect_period, divisor));
+	if (div_h > 0xf)
+		div_h = 0xf;
+
+	divisor = ((u64)NSEC_PER_SEC * (PWM_ASPEED_FIXED_PERIOD + 1)) << div_h;
+	div_l = div64_u64(priv->clk_rate * expect_period, divisor);
+
+	if (div_l == 0)
+		return -ERANGE;
+
+	div_l -= 1;
+
+	if (div_l > 255)
+		div_l = 255;
+
+	dev_dbg(chip->dev, "clk source: %ld div_h %lld, div_l : %lld\n",
+		priv->clk_rate, div_h, div_l);
+	/* duty_pt = duty_cycle * (PERIOD + 1) / period */
+	duty_pt = div64_u64(state->duty_cycle * priv->clk_rate,
+			    (u64)NSEC_PER_SEC * (div_l + 1) << div_h);
+	dev_dbg(chip->dev, "duty_cycle = %lld, duty_pt = %d\n",
+		state->duty_cycle, duty_pt);
+
+	/*
+	 * Fixed DUTY_CYCLE_PERIOD to its max value to get a
+	 * fine-grained resolution for duty_cycle at the expense of a
+	 * coarser period resolution.
+	 */
+	val = readl(priv->base + PWM_ASPEED_DUTY_CYCLE(hwpwm));
+	val &= ~PWM_ASPEED_DUTY_CYCLE_PERIOD;
+	val |= FIELD_PREP(PWM_ASPEED_DUTY_CYCLE_PERIOD,
+			  PWM_ASPEED_FIXED_PERIOD);
+	writel(val, priv->base + PWM_ASPEED_DUTY_CYCLE(hwpwm));
+
+	if (duty_pt == 0) {
+		/* emit inactive level and assert the duty counter reset */
+		clk_en = 0;
+	} else {
+		clk_en = 1;
+		if (duty_pt >= (PWM_ASPEED_FIXED_PERIOD + 1))
+			duty_pt = 0;
+		val = readl(priv->base + PWM_ASPEED_DUTY_CYCLE(hwpwm));
+		val &= ~(PWM_ASPEED_DUTY_CYCLE_RISING_POINT |
+			 PWM_ASPEED_DUTY_CYCLE_FALLING_POINT);
+		val |= FIELD_PREP(PWM_ASPEED_DUTY_CYCLE_FALLING_POINT, duty_pt);
+		writel(val, priv->base + PWM_ASPEED_DUTY_CYCLE(hwpwm));
+	}
+
+	val = readl(priv->base + PWM_ASPEED_CTRL(hwpwm));
+	val &= ~(PWM_ASPEED_CTRL_CLK_DIV_H | PWM_ASPEED_CTRL_CLK_DIV_L |
+		 PWM_ASPEED_CTRL_PIN_ENABLE | PWM_ASPEED_CTRL_CLK_ENABLE |
+		 PWM_ASPEED_CTRL_INVERSE);
+	val |= FIELD_PREP(PWM_ASPEED_CTRL_CLK_DIV_H, div_h) |
+	       FIELD_PREP(PWM_ASPEED_CTRL_CLK_DIV_L, div_l) |
+	       FIELD_PREP(PWM_ASPEED_CTRL_PIN_ENABLE, state->enabled) |
+	       FIELD_PREP(PWM_ASPEED_CTRL_CLK_ENABLE, clk_en) |
+	       FIELD_PREP(PWM_ASPEED_CTRL_INVERSE, state->polarity);
+	writel(val, priv->base + PWM_ASPEED_CTRL(hwpwm));
+
+	return 0;
+}
+
+static const struct pwm_ops aspeed_pwm_ops = {
+	.apply = aspeed_pwm_apply,
+	.get_state = aspeed_pwm_get_state,
+	.owner = THIS_MODULE,
+};
+
+static void aspeed_tach_ch_enable(struct aspeed_pwm_tach_data *priv, u8 tach_ch,
+				  bool enable)
+{
+	if (enable)
+		writel(readl(priv->base + TACH_ASPEED_CTRL(tach_ch)) |
+			       TACH_ASPEED_ENABLE,
+		       priv->base + TACH_ASPEED_CTRL(tach_ch));
+	else
+		writel(readl(priv->base + TACH_ASPEED_CTRL(tach_ch)) &
+			       ~TACH_ASPEED_ENABLE,
+		       priv->base + TACH_ASPEED_CTRL(tach_ch));
+}
+
+static int aspeed_tach_val_to_rpm(struct aspeed_pwm_tach_data *priv, u32 tach_val)
+{
+	u64 rpm;
+	u32 tach_div;
+
+	tach_div = tach_val * priv->tach_divisor * DEFAULT_FAN_PULSE_PR;
+
+	dev_dbg(priv->dev, "clk %ld, tach_val %d , tach_div %d\n",
+		priv->clk_rate, tach_val, tach_div);
+
+	rpm = (u64)priv->clk_rate * 60;
+	do_div(rpm, tach_div);
+
+	return (int)rpm;
+}
+
+static int aspeed_get_fan_tach_ch_rpm(struct aspeed_pwm_tach_data *priv,
+				      u8 fan_tach_ch)
+{
+	u32 val;
+
+	val = readl(priv->base + TACH_ASPEED_STS(fan_tach_ch));
+
+	if (!(val & TACH_ASPEED_FULL_MEASUREMENT))
+		return 0;
+	val = FIELD_GET(TACH_ASPEED_VALUE_MASK, val);
+	return aspeed_tach_val_to_rpm(priv, val);
+}
+
+static int aspeed_tach_hwmon_read(struct device *dev,
+				  enum hwmon_sensor_types type, u32 attr,
+				  int channel, long *val)
+{
+	struct aspeed_pwm_tach_data *priv = dev_get_drvdata(dev);
+	u32 reg_val;
+
+	switch (attr) {
+	case hwmon_fan_input:
+		*val = aspeed_get_fan_tach_ch_rpm(priv, channel);
+		break;
+	case hwmon_fan_div:
+		reg_val = readl(priv->base + TACH_ASPEED_CTRL(channel));
+		reg_val = FIELD_GET(TACH_ASPEED_CLK_DIV_T_MASK, reg_val);
+		*val = BIT(reg_val << 1);
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+	return 0;
+}
+
+static int aspeed_tach_hwmon_write(struct device *dev,
+				   enum hwmon_sensor_types type, u32 attr,
+				   int channel, long val)
+{
+	struct aspeed_pwm_tach_data *priv = dev_get_drvdata(dev);
+	u32 reg_val;
+
+	switch (attr) {
+	case hwmon_fan_div:
+		if (!is_power_of_2(val) || (ilog2(val) % 2) ||
+		    DIV_TO_REG(val) > 0xb)
+			return -EINVAL;
+		priv->tach_divisor = val;
+		reg_val = readl(priv->base + TACH_ASPEED_CTRL(channel));
+		reg_val &= ~TACH_ASPEED_CLK_DIV_T_MASK;
+		reg_val |= FIELD_PREP(TACH_ASPEED_CLK_DIV_T_MASK,
+				      DIV_TO_REG(priv->tach_divisor));
+		writel(reg_val, priv->base + TACH_ASPEED_CTRL(channel));
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	return 0;
+}
+
+static umode_t aspeed_tach_dev_is_visible(const void *drvdata,
+					  enum hwmon_sensor_types type,
+					  u32 attr, int channel)
+{
+	const struct aspeed_pwm_tach_data *priv = drvdata;
+
+	if (!priv->tach_present[channel])
+		return 0;
+	switch (attr) {
+	case hwmon_fan_input:
+		return 0444;
+	case hwmon_fan_div:
+		return 0644;
+	}
+	return 0;
+}
+
+static const struct hwmon_ops aspeed_tach_ops = {
+	.is_visible = aspeed_tach_dev_is_visible,
+	.read = aspeed_tach_hwmon_read,
+	.write = aspeed_tach_hwmon_write,
+};
+
+static const struct hwmon_channel_info *aspeed_tach_info[] = {
+	HWMON_CHANNEL_INFO(fan, HWMON_F_INPUT | HWMON_F_DIV, HWMON_F_INPUT | HWMON_F_DIV,
+			   HWMON_F_INPUT | HWMON_F_DIV, HWMON_F_INPUT | HWMON_F_DIV,
+			   HWMON_F_INPUT | HWMON_F_DIV, HWMON_F_INPUT | HWMON_F_DIV,
+			   HWMON_F_INPUT | HWMON_F_DIV, HWMON_F_INPUT | HWMON_F_DIV,
+			   HWMON_F_INPUT | HWMON_F_DIV, HWMON_F_INPUT | HWMON_F_DIV,
+			   HWMON_F_INPUT | HWMON_F_DIV, HWMON_F_INPUT | HWMON_F_DIV,
+			   HWMON_F_INPUT | HWMON_F_DIV, HWMON_F_INPUT | HWMON_F_DIV,
+			   HWMON_F_INPUT | HWMON_F_DIV, HWMON_F_INPUT | HWMON_F_DIV),
+	NULL
+};
+
+static const struct hwmon_chip_info aspeed_tach_chip_info = {
+	.ops = &aspeed_tach_ops,
+	.info = aspeed_tach_info,
+};
+
+static void aspeed_present_fan_tach(struct aspeed_pwm_tach_data *priv, u8 *tach_ch, int count)
+{
+	u8 ch, index;
+	u32 val;
+
+	for (index = 0; index < count; index++) {
+		ch = tach_ch[index];
+		priv->tach_present[ch] = true;
+		priv->tach_divisor = DEFAULT_TACH_DIV;
+
+		val = readl(priv->base + TACH_ASPEED_CTRL(ch));
+		val &= ~(TACH_ASPEED_INVERS_LIMIT | TACH_ASPEED_DEBOUNCE_MASK |
+			 TACH_ASPEED_IO_EDGE_MASK | TACH_ASPEED_CLK_DIV_T_MASK |
+			 TACH_ASPEED_THRESHOLD_MASK);
+		val |= (DEBOUNCE_3_CLK << TACH_ASPEED_DEBOUNCE_BIT) |
+		       F2F_EDGES |
+		       FIELD_PREP(TACH_ASPEED_CLK_DIV_T_MASK,
+				  DIV_TO_REG(priv->tach_divisor));
+		writel(val, priv->base + TACH_ASPEED_CTRL(ch));
+
+		aspeed_tach_ch_enable(priv, ch, true);
+	}
+}
+
+static int aspeed_tach_create_fan(struct device *dev, struct device_node *child,
+				  struct aspeed_pwm_tach_data *priv)
+{
+	int ret, count;
+	u8 *tach_ch;
+
+	count = of_property_count_u8_elems(child, "tach-ch");
+	if (count < 1)
+		return -EINVAL;
+	tach_ch = devm_kcalloc(dev, count, sizeof(*tach_ch), GFP_KERNEL);
+	if (!tach_ch)
+		return -ENOMEM;
+	ret = of_property_read_u8_array(child, "tach-ch", tach_ch, count);
+	if (ret)
+		return ret;
+
+	aspeed_present_fan_tach(priv, tach_ch, count);
+
+	return 0;
+}
+
+static int aspeed_pwm_tach_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev, *hwmon;
+	int ret;
+	struct device_node *child;
+	struct aspeed_pwm_tach_data *priv;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+	priv->dev = dev;
+	priv->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(priv->base))
+		return PTR_ERR(priv->base);
+
+	priv->clk = devm_clk_get_enabled(dev, NULL);
+	if (IS_ERR(priv->clk))
+		return dev_err_probe(dev, PTR_ERR(priv->clk),
+				     "Couldn't get clock\n");
+	priv->clk_rate = clk_get_rate(priv->clk);
+	priv->reset = devm_reset_control_get_exclusive(dev, NULL);
+	if (IS_ERR(priv->reset))
+		return dev_err_probe(dev, PTR_ERR(priv->reset),
+				     "Couldn't get reset control\n");
+
+	ret = reset_control_deassert(priv->reset);
+	if (ret)
+		return dev_err_probe(dev, ret,
+				     "Couldn't deassert reset control\n");
+
+	priv->chip.dev = dev;
+	priv->chip.ops = &aspeed_pwm_ops;
+	priv->chip.npwm = PWM_ASPEED_NR_PWMS;
+
+	ret = devm_pwmchip_add(dev, &priv->chip);
+	if (ret < 0) {
+		reset_control_assert(priv->reset);
+		return dev_err_probe(dev, ret, "Failed to add PWM chip\n");
+	}
+
+	for_each_child_of_node(dev->of_node, child) {
+		ret = aspeed_tach_create_fan(dev, child, priv);
+		if (ret < 0) {
+			of_node_put(child);
+			dev_warn(dev, "Failed to create fan %d", ret);
+			return 0;
+		}
+	}
+
+	hwmon = devm_hwmon_device_register_with_info(dev, "aspeed_tach", priv,
+						     &aspeed_tach_chip_info, NULL);
+	ret = PTR_ERR_OR_ZERO(hwmon);
+	if (ret) {
+		reset_control_assert(priv->reset);
+		return dev_err_probe(dev, ret,
+				     "Failed to register hwmon device\n");
+	}
+
+	return 0;
+}
+
+static int aspeed_pwm_tach_remove(struct platform_device *pdev)
+{
+	struct aspeed_pwm_tach_data *priv = platform_get_drvdata(pdev);
+
+	reset_control_assert(priv->reset);
+
+	return 0;
+}
+
+static const struct of_device_id aspeed_pwm_tach_match[] = {
+	{
+		.compatible = "aspeed,ast2600-pwm-tach",
+	},
+	{},
+};
+MODULE_DEVICE_TABLE(of, aspeed_pwm_tach_match);
+
+static struct platform_driver aspeed_pwm_tach_driver = {
+	.probe = aspeed_pwm_tach_probe,
+	.remove = aspeed_pwm_tach_remove,
+	.driver	= {
+		.name = "aspeed-g6-pwm-tach",
+		.of_match_table = aspeed_pwm_tach_match,
+	},
+};
+
+module_platform_driver(aspeed_pwm_tach_driver);
+
+MODULE_AUTHOR("Billy Tsai <billy_tsai@aspeedtech.com>");
+MODULE_DESCRIPTION("Aspeed ast2600 PWM and Fan Tach device driver");
+MODULE_LICENSE("GPL");
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 31+ messages in thread
* [PATCH RESEND v10 3/3] hwmon: (aspeed-g6-pwm-tacho): Support for ASPEED g6 PWM/Fan tach
@ 2023-11-07 10:50   ` Billy Tsai
  0 siblings, 0 replies; 31+ messages in thread
From: Billy Tsai @ 2023-11-07 10:50 UTC (permalink / raw)
  To: jdelvare, linux, robh+dt, krzysztof.kozlowski+dt, joel, andrew,
	corbet, thierry.reding, u.kleine-koenig, p.zabel, billy_tsai,
	naresh.solanki, linux-hwmon, devicetree, linux-arm-kernel,
	linux-aspeed, linux-kernel, linux-doc, linux-pwm, BMC-SW,
	patrick

The driver support two functions: PWM and Tachometer. The PWM feature can
handle up to 16 output ports, while the Tachometer can monitor to up to 16
input ports as well. This driver implements them by exposing two kernel
subsystems: PWM and HWMON. The PWM subsystem can be utilized alongside
existing drivers for controlling elements such as fans (pwm-fan.c),
beepers (pwm-beeper.c) and so on. Through the HWMON subsystem, the driver
provides sysfs interfaces for fan.

Signed-off-by: Billy Tsai <billy_tsai@aspeedtech.com>
---
 Documentation/hwmon/aspeed-g6-pwm-tach.rst |  26 +
 Documentation/hwmon/index.rst              |   1 +
 drivers/hwmon/Kconfig                      |  11 +
 drivers/hwmon/Makefile                     |   1 +
 drivers/hwmon/aspeed-g6-pwm-tach.c         | 539 +++++++++++++++++++++
 5 files changed, 578 insertions(+)
 create mode 100644 Documentation/hwmon/aspeed-g6-pwm-tach.rst
 create mode 100644 drivers/hwmon/aspeed-g6-pwm-tach.c

diff --git a/Documentation/hwmon/aspeed-g6-pwm-tach.rst b/Documentation/hwmon/aspeed-g6-pwm-tach.rst
new file mode 100644
index 000000000000..17398fe397fe
--- /dev/null
+++ b/Documentation/hwmon/aspeed-g6-pwm-tach.rst
@@ -0,0 +1,26 @@
+.. SPDX-License-Identifier: GPL-2.0-or-later
+
+Kernel driver aspeed-g6-pwm-tach
+=================================
+
+Supported chips:
+	ASPEED AST2600
+
+Authors:
+	<billy_tsai@aspeedtech.com>
+
+Description:
+------------
+This driver implements support for ASPEED AST2600 Fan Tacho controller.
+The controller supports up to 16 tachometer inputs.
+
+The driver provides the following sensor accesses in sysfs:
+
+=============== ======= ======================================================
+fanX_input	ro	provide current fan rotation value in RPM as reported
+			by the fan to the device.
+fanX_div	rw	Fan divisor: Supported value are power of 4 (1, 4, 16
+                        64, ... 4194304)
+                        The larger divisor, the less rpm accuracy and the less
+                        affected by fan signal glitch.
+=============== ======= ======================================================
diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst
index 042e1cf9501b..75b869ff6c53 100644
--- a/Documentation/hwmon/index.rst
+++ b/Documentation/hwmon/index.rst
@@ -44,6 +44,7 @@ Hardware Monitoring Kernel Drivers
    aquacomputer_d5next
    asb100
    asc7621
+   aspeed-g6-pwm-tach
    aspeed-pwm-tacho
    asus_ec_sensors
    asus_wmi_sensors
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 307477b8a371..75fbea7e81e2 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -412,6 +412,17 @@ config SENSORS_ASPEED
 	  This driver can also be built as a module. If so, the module
 	  will be called aspeed_pwm_tacho.
 
+config SENSORS_ASPEED_G6
+	tristate "ASPEED g6 PWM and Fan tach driver"
+	depends on ARCH_ASPEED || COMPILE_TEST
+	depends on PWM
+	help
+	  This driver provides support for ASPEED G6 PWM and Fan Tach
+	  controllers.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called aspeed_pwm_tacho.
+
 config SENSORS_ATXP1
 	tristate "Attansic ATXP1 VID controller"
 	depends on I2C
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index 3f4b0fda0998..51de5c1d5f1e 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -55,6 +55,7 @@ obj-$(CONFIG_SENSORS_ARM_SCPI)	+= scpi-hwmon.o
 obj-$(CONFIG_SENSORS_AS370)	+= as370-hwmon.o
 obj-$(CONFIG_SENSORS_ASC7621)	+= asc7621.o
 obj-$(CONFIG_SENSORS_ASPEED)	+= aspeed-pwm-tacho.o
+obj-$(CONFIG_SENSORS_ASPEED_G6) += aspeed-g6-pwm-tach.o
 obj-$(CONFIG_SENSORS_ATXP1)	+= atxp1.o
 obj-$(CONFIG_SENSORS_AXI_FAN_CONTROL) += axi-fan-control.o
 obj-$(CONFIG_SENSORS_BT1_PVT)	+= bt1-pvt.o
diff --git a/drivers/hwmon/aspeed-g6-pwm-tach.c b/drivers/hwmon/aspeed-g6-pwm-tach.c
new file mode 100644
index 000000000000..504574e8940c
--- /dev/null
+++ b/drivers/hwmon/aspeed-g6-pwm-tach.c
@@ -0,0 +1,539 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2021 Aspeed Technology Inc.
+ *
+ * PWM/TACH controller driver for Aspeed ast2600 SoCs.
+ * This drivers doesn't support earlier version of the IP.
+ *
+ * The hardware operates in time quantities of length
+ * Q := (DIV_L + 1) << DIV_H / input-clk
+ * The length of a PWM period is (DUTY_CYCLE_PERIOD + 1) * Q.
+ * The maximal value for DUTY_CYCLE_PERIOD is used here to provide
+ * a fine grained selection for the duty cycle.
+ *
+ * This driver uses DUTY_CYCLE_RISING_POINT = 0, so from the start of a
+ * period the output is active until DUTY_CYCLE_FALLING_POINT * Q. Note
+ * that if DUTY_CYCLE_RISING_POINT = DUTY_CYCLE_FALLING_POINT the output is
+ * always active.
+ *
+ * Register usage:
+ * PIN_ENABLE: When it is unset the pwm controller will emit inactive level to the external.
+ * Use to determine whether the PWM channel is enabled or disabled
+ * CLK_ENABLE: When it is unset the pwm controller will assert the duty counter reset and
+ * emit inactive level to the PIN_ENABLE mux after that the driver can still change the pwm period
+ * and duty and the value will apply when CLK_ENABLE be set again.
+ * Use to determine whether duty_cycle bigger than 0.
+ * PWM_ASPEED_CTRL_INVERSE: When it is toggled the output value will inverse immediately.
+ * PWM_ASPEED_DUTY_CYCLE_FALLING_POINT/PWM_ASPEED_DUTY_CYCLE_RISING_POINT: When these two
+ * values are equal it means the duty cycle = 100%.
+ *
+ * The glitch may generate at:
+ * - Enabled changing when the duty_cycle bigger than 0% and less than 100%.
+ * - Polarity changing when the duty_cycle bigger than 0% and less than 100%.
+ *
+ * Limitations:
+ * - When changing both duty cycle and period, we cannot prevent in
+ *   software that the output might produce a period with mixed
+ *   settings.
+ * - Disabling the PWM doesn't complete the current period.
+ *
+ * Improvements:
+ * - When only changing one of duty cycle or period, our pwm controller will not
+ *   generate the glitch, the configure will change at next cycle of pwm.
+ *   This improvement can disable/enable through PWM_ASPEED_CTRL_DUTY_SYNC_DISABLE.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/errno.h>
+#include <linux/hwmon.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/math64.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+#include <linux/reset.h>
+#include <linux/sysfs.h>
+
+/* The channel number of Aspeed pwm controller */
+#define PWM_ASPEED_NR_PWMS			16
+/* PWM Control Register */
+#define PWM_ASPEED_CTRL(ch)			((ch) * 0x10 + 0x00)
+#define PWM_ASPEED_CTRL_LOAD_SEL_RISING_AS_WDT	BIT(19)
+#define PWM_ASPEED_CTRL_DUTY_LOAD_AS_WDT_ENABLE	BIT(18)
+#define PWM_ASPEED_CTRL_DUTY_SYNC_DISABLE	BIT(17)
+#define PWM_ASPEED_CTRL_CLK_ENABLE		BIT(16)
+#define PWM_ASPEED_CTRL_LEVEL_OUTPUT		BIT(15)
+#define PWM_ASPEED_CTRL_INVERSE			BIT(14)
+#define PWM_ASPEED_CTRL_OPEN_DRAIN_ENABLE	BIT(13)
+#define PWM_ASPEED_CTRL_PIN_ENABLE		BIT(12)
+#define PWM_ASPEED_CTRL_CLK_DIV_H		GENMASK(11, 8)
+#define PWM_ASPEED_CTRL_CLK_DIV_L		GENMASK(7, 0)
+
+/* PWM Duty Cycle Register */
+#define PWM_ASPEED_DUTY_CYCLE(ch)		((ch) * 0x10 + 0x04)
+#define PWM_ASPEED_DUTY_CYCLE_PERIOD		GENMASK(31, 24)
+#define PWM_ASPEED_DUTY_CYCLE_POINT_AS_WDT	GENMASK(23, 16)
+#define PWM_ASPEED_DUTY_CYCLE_FALLING_POINT	GENMASK(15, 8)
+#define PWM_ASPEED_DUTY_CYCLE_RISING_POINT	GENMASK(7, 0)
+
+/* PWM fixed value */
+#define PWM_ASPEED_FIXED_PERIOD			FIELD_MAX(PWM_ASPEED_DUTY_CYCLE_PERIOD)
+
+/* The channel number of Aspeed tach controller */
+#define TACH_ASPEED_NR_TACHS		16
+/* TACH Control Register */
+#define TACH_ASPEED_CTRL(ch)		(((ch) * 0x10) + 0x08)
+#define TACH_ASPEED_IER			BIT(31)
+#define TACH_ASPEED_INVERS_LIMIT	BIT(30)
+#define TACH_ASPEED_LOOPBACK		BIT(29)
+#define TACH_ASPEED_ENABLE		BIT(28)
+#define TACH_ASPEED_DEBOUNCE_MASK	GENMASK(27, 26)
+#define TACH_ASPEED_DEBOUNCE_BIT	26
+#define TACH_ASPEED_IO_EDGE_MASK	GENMASK(25, 24)
+#define TACH_ASPEED_IO_EDGE_BIT		24
+#define TACH_ASPEED_CLK_DIV_T_MASK	GENMASK(23, 20)
+#define TACH_ASPEED_CLK_DIV_BIT		20
+#define TACH_ASPEED_THRESHOLD_MASK	GENMASK(19, 0)
+/* [27:26] */
+#define DEBOUNCE_3_CLK			0x00
+#define DEBOUNCE_2_CLK			0x01
+#define DEBOUNCE_1_CLK			0x02
+#define DEBOUNCE_0_CLK			0x03
+/* [25:24] */
+#define F2F_EDGES			0x00
+#define R2R_EDGES			0x01
+#define BOTH_EDGES			0x02
+/* [23:20] */
+/* divisor = 4 to the nth power, n = register value */
+#define DEFAULT_TACH_DIV		1024
+#define DIV_TO_REG(divisor)		(ilog2(divisor) >> 1)
+
+/* TACH Status Register */
+#define TACH_ASPEED_STS(ch)		(((ch) * 0x10) + 0x0C)
+
+/*PWM_TACH_STS */
+#define TACH_ASPEED_ISR			BIT(31)
+#define TACH_ASPEED_PWM_OUT		BIT(25)
+#define TACH_ASPEED_PWM_OEN		BIT(24)
+#define TACH_ASPEED_DEB_INPUT		BIT(23)
+#define TACH_ASPEED_RAW_INPUT		BIT(22)
+#define TACH_ASPEED_VALUE_UPDATE	BIT(21)
+#define TACH_ASPEED_FULL_MEASUREMENT	BIT(20)
+#define TACH_ASPEED_VALUE_MASK		GENMASK(19, 0)
+/**********************************************************
+ * Software setting
+ *********************************************************/
+#define DEFAULT_FAN_PULSE_PR		2
+
+struct aspeed_pwm_tach_data {
+	struct device *dev;
+	void __iomem *base;
+	struct clk *clk;
+	struct reset_control *reset;
+	unsigned long clk_rate;
+	struct pwm_chip chip;
+	bool tach_present[TACH_ASPEED_NR_TACHS];
+	u32 tach_divisor;
+};
+
+static inline struct aspeed_pwm_tach_data *
+aspeed_pwm_chip_to_data(struct pwm_chip *chip)
+{
+	return container_of(chip, struct aspeed_pwm_tach_data, chip);
+}
+
+static int aspeed_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
+				struct pwm_state *state)
+{
+	struct aspeed_pwm_tach_data *priv = aspeed_pwm_chip_to_data(chip);
+	u32 hwpwm = pwm->hwpwm;
+	bool polarity, pin_en, clk_en;
+	u32 duty_pt, val;
+	u64 div_h, div_l, duty_cycle_period, dividend;
+
+	val = readl(priv->base + PWM_ASPEED_CTRL(hwpwm));
+	polarity = FIELD_GET(PWM_ASPEED_CTRL_INVERSE, val);
+	pin_en = FIELD_GET(PWM_ASPEED_CTRL_PIN_ENABLE, val);
+	clk_en = FIELD_GET(PWM_ASPEED_CTRL_CLK_ENABLE, val);
+	div_h = FIELD_GET(PWM_ASPEED_CTRL_CLK_DIV_H, val);
+	div_l = FIELD_GET(PWM_ASPEED_CTRL_CLK_DIV_L, val);
+	val = readl(priv->base + PWM_ASPEED_DUTY_CYCLE(hwpwm));
+	duty_pt = FIELD_GET(PWM_ASPEED_DUTY_CYCLE_FALLING_POINT, val);
+	duty_cycle_period = FIELD_GET(PWM_ASPEED_DUTY_CYCLE_PERIOD, val);
+	/*
+	 * This multiplication doesn't overflow, the upper bound is
+	 * 1000000000 * 256 * 256 << 15 = 0x1dcd650000000000
+	 */
+	dividend = (u64)NSEC_PER_SEC * (div_l + 1) * (duty_cycle_period + 1)
+		       << div_h;
+	state->period = DIV_ROUND_UP_ULL(dividend, priv->clk_rate);
+
+	if (clk_en && duty_pt) {
+		dividend = (u64)NSEC_PER_SEC * (div_l + 1) * duty_pt
+				 << div_h;
+		state->duty_cycle = DIV_ROUND_UP_ULL(dividend, priv->clk_rate);
+	} else {
+		state->duty_cycle = clk_en ? state->period : 0;
+	}
+	state->polarity = polarity ? PWM_POLARITY_INVERSED : PWM_POLARITY_NORMAL;
+	state->enabled = pin_en;
+	return 0;
+}
+
+static int aspeed_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+			    const struct pwm_state *state)
+{
+	struct aspeed_pwm_tach_data *priv = aspeed_pwm_chip_to_data(chip);
+	u32 hwpwm = pwm->hwpwm, duty_pt, val;
+	u64 div_h, div_l, divisor, expect_period;
+	bool clk_en;
+
+	expect_period = div64_u64(ULLONG_MAX, (u64)priv->clk_rate);
+	expect_period = min(expect_period, state->period);
+	dev_dbg(chip->dev, "expect period: %lldns, duty_cycle: %lldns",
+		expect_period, state->duty_cycle);
+	/*
+	 * Pick the smallest value for div_h so that div_l can be the biggest
+	 * which results in a finer resolution near the target period value.
+	 */
+	divisor = (u64)NSEC_PER_SEC * (PWM_ASPEED_FIXED_PERIOD + 1) *
+		  (FIELD_MAX(PWM_ASPEED_CTRL_CLK_DIV_L) + 1);
+	div_h = order_base_2(DIV64_U64_ROUND_UP(priv->clk_rate * expect_period, divisor));
+	if (div_h > 0xf)
+		div_h = 0xf;
+
+	divisor = ((u64)NSEC_PER_SEC * (PWM_ASPEED_FIXED_PERIOD + 1)) << div_h;
+	div_l = div64_u64(priv->clk_rate * expect_period, divisor);
+
+	if (div_l == 0)
+		return -ERANGE;
+
+	div_l -= 1;
+
+	if (div_l > 255)
+		div_l = 255;
+
+	dev_dbg(chip->dev, "clk source: %ld div_h %lld, div_l : %lld\n",
+		priv->clk_rate, div_h, div_l);
+	/* duty_pt = duty_cycle * (PERIOD + 1) / period */
+	duty_pt = div64_u64(state->duty_cycle * priv->clk_rate,
+			    (u64)NSEC_PER_SEC * (div_l + 1) << div_h);
+	dev_dbg(chip->dev, "duty_cycle = %lld, duty_pt = %d\n",
+		state->duty_cycle, duty_pt);
+
+	/*
+	 * Fixed DUTY_CYCLE_PERIOD to its max value to get a
+	 * fine-grained resolution for duty_cycle at the expense of a
+	 * coarser period resolution.
+	 */
+	val = readl(priv->base + PWM_ASPEED_DUTY_CYCLE(hwpwm));
+	val &= ~PWM_ASPEED_DUTY_CYCLE_PERIOD;
+	val |= FIELD_PREP(PWM_ASPEED_DUTY_CYCLE_PERIOD,
+			  PWM_ASPEED_FIXED_PERIOD);
+	writel(val, priv->base + PWM_ASPEED_DUTY_CYCLE(hwpwm));
+
+	if (duty_pt == 0) {
+		/* emit inactive level and assert the duty counter reset */
+		clk_en = 0;
+	} else {
+		clk_en = 1;
+		if (duty_pt >= (PWM_ASPEED_FIXED_PERIOD + 1))
+			duty_pt = 0;
+		val = readl(priv->base + PWM_ASPEED_DUTY_CYCLE(hwpwm));
+		val &= ~(PWM_ASPEED_DUTY_CYCLE_RISING_POINT |
+			 PWM_ASPEED_DUTY_CYCLE_FALLING_POINT);
+		val |= FIELD_PREP(PWM_ASPEED_DUTY_CYCLE_FALLING_POINT, duty_pt);
+		writel(val, priv->base + PWM_ASPEED_DUTY_CYCLE(hwpwm));
+	}
+
+	val = readl(priv->base + PWM_ASPEED_CTRL(hwpwm));
+	val &= ~(PWM_ASPEED_CTRL_CLK_DIV_H | PWM_ASPEED_CTRL_CLK_DIV_L |
+		 PWM_ASPEED_CTRL_PIN_ENABLE | PWM_ASPEED_CTRL_CLK_ENABLE |
+		 PWM_ASPEED_CTRL_INVERSE);
+	val |= FIELD_PREP(PWM_ASPEED_CTRL_CLK_DIV_H, div_h) |
+	       FIELD_PREP(PWM_ASPEED_CTRL_CLK_DIV_L, div_l) |
+	       FIELD_PREP(PWM_ASPEED_CTRL_PIN_ENABLE, state->enabled) |
+	       FIELD_PREP(PWM_ASPEED_CTRL_CLK_ENABLE, clk_en) |
+	       FIELD_PREP(PWM_ASPEED_CTRL_INVERSE, state->polarity);
+	writel(val, priv->base + PWM_ASPEED_CTRL(hwpwm));
+
+	return 0;
+}
+
+static const struct pwm_ops aspeed_pwm_ops = {
+	.apply = aspeed_pwm_apply,
+	.get_state = aspeed_pwm_get_state,
+	.owner = THIS_MODULE,
+};
+
+static void aspeed_tach_ch_enable(struct aspeed_pwm_tach_data *priv, u8 tach_ch,
+				  bool enable)
+{
+	if (enable)
+		writel(readl(priv->base + TACH_ASPEED_CTRL(tach_ch)) |
+			       TACH_ASPEED_ENABLE,
+		       priv->base + TACH_ASPEED_CTRL(tach_ch));
+	else
+		writel(readl(priv->base + TACH_ASPEED_CTRL(tach_ch)) &
+			       ~TACH_ASPEED_ENABLE,
+		       priv->base + TACH_ASPEED_CTRL(tach_ch));
+}
+
+static int aspeed_tach_val_to_rpm(struct aspeed_pwm_tach_data *priv, u32 tach_val)
+{
+	u64 rpm;
+	u32 tach_div;
+
+	tach_div = tach_val * priv->tach_divisor * DEFAULT_FAN_PULSE_PR;
+
+	dev_dbg(priv->dev, "clk %ld, tach_val %d , tach_div %d\n",
+		priv->clk_rate, tach_val, tach_div);
+
+	rpm = (u64)priv->clk_rate * 60;
+	do_div(rpm, tach_div);
+
+	return (int)rpm;
+}
+
+static int aspeed_get_fan_tach_ch_rpm(struct aspeed_pwm_tach_data *priv,
+				      u8 fan_tach_ch)
+{
+	u32 val;
+
+	val = readl(priv->base + TACH_ASPEED_STS(fan_tach_ch));
+
+	if (!(val & TACH_ASPEED_FULL_MEASUREMENT))
+		return 0;
+	val = FIELD_GET(TACH_ASPEED_VALUE_MASK, val);
+	return aspeed_tach_val_to_rpm(priv, val);
+}
+
+static int aspeed_tach_hwmon_read(struct device *dev,
+				  enum hwmon_sensor_types type, u32 attr,
+				  int channel, long *val)
+{
+	struct aspeed_pwm_tach_data *priv = dev_get_drvdata(dev);
+	u32 reg_val;
+
+	switch (attr) {
+	case hwmon_fan_input:
+		*val = aspeed_get_fan_tach_ch_rpm(priv, channel);
+		break;
+	case hwmon_fan_div:
+		reg_val = readl(priv->base + TACH_ASPEED_CTRL(channel));
+		reg_val = FIELD_GET(TACH_ASPEED_CLK_DIV_T_MASK, reg_val);
+		*val = BIT(reg_val << 1);
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+	return 0;
+}
+
+static int aspeed_tach_hwmon_write(struct device *dev,
+				   enum hwmon_sensor_types type, u32 attr,
+				   int channel, long val)
+{
+	struct aspeed_pwm_tach_data *priv = dev_get_drvdata(dev);
+	u32 reg_val;
+
+	switch (attr) {
+	case hwmon_fan_div:
+		if (!is_power_of_2(val) || (ilog2(val) % 2) ||
+		    DIV_TO_REG(val) > 0xb)
+			return -EINVAL;
+		priv->tach_divisor = val;
+		reg_val = readl(priv->base + TACH_ASPEED_CTRL(channel));
+		reg_val &= ~TACH_ASPEED_CLK_DIV_T_MASK;
+		reg_val |= FIELD_PREP(TACH_ASPEED_CLK_DIV_T_MASK,
+				      DIV_TO_REG(priv->tach_divisor));
+		writel(reg_val, priv->base + TACH_ASPEED_CTRL(channel));
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	return 0;
+}
+
+static umode_t aspeed_tach_dev_is_visible(const void *drvdata,
+					  enum hwmon_sensor_types type,
+					  u32 attr, int channel)
+{
+	const struct aspeed_pwm_tach_data *priv = drvdata;
+
+	if (!priv->tach_present[channel])
+		return 0;
+	switch (attr) {
+	case hwmon_fan_input:
+		return 0444;
+	case hwmon_fan_div:
+		return 0644;
+	}
+	return 0;
+}
+
+static const struct hwmon_ops aspeed_tach_ops = {
+	.is_visible = aspeed_tach_dev_is_visible,
+	.read = aspeed_tach_hwmon_read,
+	.write = aspeed_tach_hwmon_write,
+};
+
+static const struct hwmon_channel_info *aspeed_tach_info[] = {
+	HWMON_CHANNEL_INFO(fan, HWMON_F_INPUT | HWMON_F_DIV, HWMON_F_INPUT | HWMON_F_DIV,
+			   HWMON_F_INPUT | HWMON_F_DIV, HWMON_F_INPUT | HWMON_F_DIV,
+			   HWMON_F_INPUT | HWMON_F_DIV, HWMON_F_INPUT | HWMON_F_DIV,
+			   HWMON_F_INPUT | HWMON_F_DIV, HWMON_F_INPUT | HWMON_F_DIV,
+			   HWMON_F_INPUT | HWMON_F_DIV, HWMON_F_INPUT | HWMON_F_DIV,
+			   HWMON_F_INPUT | HWMON_F_DIV, HWMON_F_INPUT | HWMON_F_DIV,
+			   HWMON_F_INPUT | HWMON_F_DIV, HWMON_F_INPUT | HWMON_F_DIV,
+			   HWMON_F_INPUT | HWMON_F_DIV, HWMON_F_INPUT | HWMON_F_DIV),
+	NULL
+};
+
+static const struct hwmon_chip_info aspeed_tach_chip_info = {
+	.ops = &aspeed_tach_ops,
+	.info = aspeed_tach_info,
+};
+
+static void aspeed_present_fan_tach(struct aspeed_pwm_tach_data *priv, u8 *tach_ch, int count)
+{
+	u8 ch, index;
+	u32 val;
+
+	for (index = 0; index < count; index++) {
+		ch = tach_ch[index];
+		priv->tach_present[ch] = true;
+		priv->tach_divisor = DEFAULT_TACH_DIV;
+
+		val = readl(priv->base + TACH_ASPEED_CTRL(ch));
+		val &= ~(TACH_ASPEED_INVERS_LIMIT | TACH_ASPEED_DEBOUNCE_MASK |
+			 TACH_ASPEED_IO_EDGE_MASK | TACH_ASPEED_CLK_DIV_T_MASK |
+			 TACH_ASPEED_THRESHOLD_MASK);
+		val |= (DEBOUNCE_3_CLK << TACH_ASPEED_DEBOUNCE_BIT) |
+		       F2F_EDGES |
+		       FIELD_PREP(TACH_ASPEED_CLK_DIV_T_MASK,
+				  DIV_TO_REG(priv->tach_divisor));
+		writel(val, priv->base + TACH_ASPEED_CTRL(ch));
+
+		aspeed_tach_ch_enable(priv, ch, true);
+	}
+}
+
+static int aspeed_tach_create_fan(struct device *dev, struct device_node *child,
+				  struct aspeed_pwm_tach_data *priv)
+{
+	int ret, count;
+	u8 *tach_ch;
+
+	count = of_property_count_u8_elems(child, "tach-ch");
+	if (count < 1)
+		return -EINVAL;
+	tach_ch = devm_kcalloc(dev, count, sizeof(*tach_ch), GFP_KERNEL);
+	if (!tach_ch)
+		return -ENOMEM;
+	ret = of_property_read_u8_array(child, "tach-ch", tach_ch, count);
+	if (ret)
+		return ret;
+
+	aspeed_present_fan_tach(priv, tach_ch, count);
+
+	return 0;
+}
+
+static int aspeed_pwm_tach_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev, *hwmon;
+	int ret;
+	struct device_node *child;
+	struct aspeed_pwm_tach_data *priv;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+	priv->dev = dev;
+	priv->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(priv->base))
+		return PTR_ERR(priv->base);
+
+	priv->clk = devm_clk_get_enabled(dev, NULL);
+	if (IS_ERR(priv->clk))
+		return dev_err_probe(dev, PTR_ERR(priv->clk),
+				     "Couldn't get clock\n");
+	priv->clk_rate = clk_get_rate(priv->clk);
+	priv->reset = devm_reset_control_get_exclusive(dev, NULL);
+	if (IS_ERR(priv->reset))
+		return dev_err_probe(dev, PTR_ERR(priv->reset),
+				     "Couldn't get reset control\n");
+
+	ret = reset_control_deassert(priv->reset);
+	if (ret)
+		return dev_err_probe(dev, ret,
+				     "Couldn't deassert reset control\n");
+
+	priv->chip.dev = dev;
+	priv->chip.ops = &aspeed_pwm_ops;
+	priv->chip.npwm = PWM_ASPEED_NR_PWMS;
+
+	ret = devm_pwmchip_add(dev, &priv->chip);
+	if (ret < 0) {
+		reset_control_assert(priv->reset);
+		return dev_err_probe(dev, ret, "Failed to add PWM chip\n");
+	}
+
+	for_each_child_of_node(dev->of_node, child) {
+		ret = aspeed_tach_create_fan(dev, child, priv);
+		if (ret < 0) {
+			of_node_put(child);
+			dev_warn(dev, "Failed to create fan %d", ret);
+			return 0;
+		}
+	}
+
+	hwmon = devm_hwmon_device_register_with_info(dev, "aspeed_tach", priv,
+						     &aspeed_tach_chip_info, NULL);
+	ret = PTR_ERR_OR_ZERO(hwmon);
+	if (ret) {
+		reset_control_assert(priv->reset);
+		return dev_err_probe(dev, ret,
+				     "Failed to register hwmon device\n");
+	}
+
+	return 0;
+}
+
+static int aspeed_pwm_tach_remove(struct platform_device *pdev)
+{
+	struct aspeed_pwm_tach_data *priv = platform_get_drvdata(pdev);
+
+	reset_control_assert(priv->reset);
+
+	return 0;
+}
+
+static const struct of_device_id aspeed_pwm_tach_match[] = {
+	{
+		.compatible = "aspeed,ast2600-pwm-tach",
+	},
+	{},
+};
+MODULE_DEVICE_TABLE(of, aspeed_pwm_tach_match);
+
+static struct platform_driver aspeed_pwm_tach_driver = {
+	.probe = aspeed_pwm_tach_probe,
+	.remove = aspeed_pwm_tach_remove,
+	.driver	= {
+		.name = "aspeed-g6-pwm-tach",
+		.of_match_table = aspeed_pwm_tach_match,
+	},
+};
+
+module_platform_driver(aspeed_pwm_tach_driver);
+
+MODULE_AUTHOR("Billy Tsai <billy_tsai@aspeedtech.com>");
+MODULE_DESCRIPTION("Aspeed ast2600 PWM and Fan Tach device driver");
+MODULE_LICENSE("GPL");
-- 
2.25.1


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

^ permalink raw reply related	[flat|nested] 31+ messages in thread
* Re: [PATCH RESEND v10 0/3] Support pwm/tach driver for aspeed ast26xx
  2023-11-07 10:50 ` Billy Tsai
@ 2023-11-07 19:02   ` Guenter Roeck
  -1 siblings, 0 replies; 31+ messages in thread
From: Guenter Roeck @ 2023-11-07 19:02 UTC (permalink / raw)
  To: Billy Tsai, jdelvare, robh+dt, krzysztof.kozlowski+dt, joel,
	andrew, corbet, thierry.reding, u.kleine-koenig, p.zabel,
	naresh.solanki, linux-hwmon, devicetree, linux-arm-kernel,
	linux-aspeed, linux-kernel, linux-doc, linux-pwm, BMC-SW,
	patrick

On 11/7/23 02:50, Billy Tsai wrote:
> Unlike the old design that the register setting of the TACH should based
> on the configure of the PWM. In ast26xx, the dependency between pwm and
> tach controller is eliminated and becomes a separate hardware block. One
> is used to provide pwm output and another is used to monitor the frequency
> of the input. This driver implements them by exposing two kernel
> subsystems: PWM and HWMON. The PWM subsystem can be utilized alongside
> existing drivers for controlling elements such as fans (pwm-fan.c),
> beepers (pwm-beeper.c) and so on. Through the HWMON subsystem, the driver
> provides sysfs interfaces for fan.
> 
> Changes since v9:
> Change the type of fan-driving-mode to string
> Fix some typos and formatting issues.
> 

What is the resend about ?

Guenter


^ permalink raw reply	[flat|nested] 31+ messages in thread
* Re: [PATCH RESEND v10 0/3] Support pwm/tach driver for aspeed ast26xx
@ 2023-11-07 19:02   ` Guenter Roeck
  0 siblings, 0 replies; 31+ messages in thread
From: Guenter Roeck @ 2023-11-07 19:02 UTC (permalink / raw)
  To: Billy Tsai, jdelvare, robh+dt, krzysztof.kozlowski+dt, joel,
	andrew, corbet, thierry.reding, u.kleine-koenig, p.zabel,
	naresh.solanki, linux-hwmon, devicetree, linux-arm-kernel,
	linux-aspeed, linux-kernel, linux-doc, linux-pwm, BMC-SW,
	patrick

On 11/7/23 02:50, Billy Tsai wrote:
> Unlike the old design that the register setting of the TACH should based
> on the configure of the PWM. In ast26xx, the dependency between pwm and
> tach controller is eliminated and becomes a separate hardware block. One
> is used to provide pwm output and another is used to monitor the frequency
> of the input. This driver implements them by exposing two kernel
> subsystems: PWM and HWMON. The PWM subsystem can be utilized alongside
> existing drivers for controlling elements such as fans (pwm-fan.c),
> beepers (pwm-beeper.c) and so on. Through the HWMON subsystem, the driver
> provides sysfs interfaces for fan.
> 
> Changes since v9:
> Change the type of fan-driving-mode to string
> Fix some typos and formatting issues.
> 

What is the resend about ?

Guenter


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

^ permalink raw reply	[flat|nested] 31+ messages in thread
* Re: [PATCH RESEND v10 0/3] Support pwm/tach driver for aspeed ast26xx
       [not found]   ` <SG2PR06MB33658A0B3EA8FD0870D8AC388BA8A@SG2PR06MB3365.apcprd06.prod.outlook.com>
@ 2023-11-08  6:03     ` Guenter Roeck
  0 siblings, 0 replies; 31+ messages in thread
From: Guenter Roeck @ 2023-11-08  6:03 UTC (permalink / raw)
  To: Billy Tsai; +Cc: linux-hwmon

On 11/7/23 18:07, Billy Tsai wrote:
> On 11/7/23 02:50, Billy Tsai wrote:
>>> Unlike the old design that the register setting of the TACH should based
>>> on the configure of the PWM. In ast26xx, the dependency between pwm and
>>> tach controller is eliminated and becomes a separate hardware block. One
>>> is used to provide pwm output and another is used to monitor the frequency
>>> of the input. This driver implements them by exposing two kernel
>>> subsystems: PWM and HWMON. The PWM subsystem can be utilized alongside
>>> existing drivers for controlling elements such as fans (pwm-fan.c),
>>> beepers (pwm-beeper.c) and so on. Through the HWMON subsystem, the driver
>>> provides sysfs interfaces for fan.
>>>
>>> Changes since v9:
>>> Change the type of fan-driving-mode to string
>>> Fix some typos and formatting issues.
>>>
> 
>> What is the resend about ?
> 
> Hi Guenter,
> 
> The reason for the resend is simply to remove the 'Change-Id' in the commit log, which
> will get the error for running scripts/checkpatch.pl.
> 

You should mention that in the change log, and please _never_ drop
the mailing list from your replies.

Thanks,
Guenter


^ permalink raw reply	[flat|nested] 31+ messages in thread
* Re: [PATCH RESEND v10 1/3] dt-bindings: hwmon: fan: Add fan binding to schema
  2023-11-07 10:50   ` Billy Tsai
@ 2023-11-08 18:16     ` Rob Herring
  -1 siblings, 0 replies; 31+ messages in thread
From: Rob Herring @ 2023-11-08 18:16 UTC (permalink / raw)
  To: Billy Tsai
  Cc: jdelvare, linux, krzysztof.kozlowski+dt, joel, andrew, corbet,
	thierry.reding, u.kleine-koenig, p.zabel, naresh.solanki,
	linux-hwmon, devicetree, linux-arm-kernel, linux-aspeed,
	linux-kernel, linux-doc, linux-pwm, BMC-SW, patrick

On Tue, Nov 07, 2023 at 06:50:23PM +0800, Billy Tsai wrote:
> From: Naresh Solanki <naresh.solanki@9elements.com>
> 
> Add common fan properties bindings to a schema.
> 
> Bindings for fan controllers can reference the common schema for the
> fan
> 
> child nodes:
> 
>   patternProperties:
>     "^fan@[0-2]":
>       type: object
>       $ref: fan-common.yaml#
>       unevaluatedProperties: false
> 
> Signed-off-by: Naresh Solanki <naresh.solanki@9elements.com>
> Signed-off-by: Billy Tsai <billy_tsai@aspeedtech.com>
> ---
>  .../devicetree/bindings/hwmon/fan-common.yaml | 78 +++++++++++++++++++
>  1 file changed, 78 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/hwmon/fan-common.yaml

Looking pretty good to me. It's disappointing that no one else 
interested in upstreaming their fan controller can be bothered to 
comment.

> 
> diff --git a/Documentation/devicetree/bindings/hwmon/fan-common.yaml b/Documentation/devicetree/bindings/hwmon/fan-common.yaml
> new file mode 100644
> index 000000000000..be4ce3bd7f22
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/hwmon/fan-common.yaml
> @@ -0,0 +1,78 @@
> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/hwmon/fan-common.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Common Fan Properties
> +
> +maintainers:
> +  - Naresh Solanki <naresh.solanki@9elements.com>
> +  - Billy Tsai <billy_tsai@aspeedtech.com>
> +
> +properties:
> +  max-rpm:
> +    description:
> +      Max RPM supported by fan.
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    maximum: 100000
> +
> +  min-rpm:
> +    description:
> +      Min RPM supported by fan.
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    maximum: 1000
> +
> +  pulses-per-revolution:
> +    description:
> +      The number of pulse from fan sensor per revolution.
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    maximum: 4
> +
> +  tach-div:
> +    description:
> +      Divisor for the tach sampling clock, which determines the sensitivity of the tach pin.
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +
> +  target-rpm:
> +    description:
> +      The default desired fan speed in RPM.
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +
> +  fan-driving-mode:
> +    description:
> +      Select the driving mode of the fan.(DC, PWM and so on)
> +    $ref: /schemas/types.yaml#/definitions/string

You need to define the possible values. I assume it's:

enum:
  - dc
  - pwm
  - anything else???

With that,

Reviewed-by: Rob Herring <robh@kernel.org>

^ permalink raw reply	[flat|nested] 31+ messages in thread
* Re: [PATCH RESEND v10 1/3] dt-bindings: hwmon: fan: Add fan binding to schema
@ 2023-11-08 18:16     ` Rob Herring
  0 siblings, 0 replies; 31+ messages in thread
From: Rob Herring @ 2023-11-08 18:16 UTC (permalink / raw)
  To: Billy Tsai
  Cc: jdelvare, linux, krzysztof.kozlowski+dt, joel, andrew, corbet,
	thierry.reding, u.kleine-koenig, p.zabel, naresh.solanki,
	linux-hwmon, devicetree, linux-arm-kernel, linux-aspeed,
	linux-kernel, linux-doc, linux-pwm, BMC-SW, patrick

On Tue, Nov 07, 2023 at 06:50:23PM +0800, Billy Tsai wrote:
> From: Naresh Solanki <naresh.solanki@9elements.com>
> 
> Add common fan properties bindings to a schema.
> 
> Bindings for fan controllers can reference the common schema for the
> fan
> 
> child nodes:
> 
>   patternProperties:
>     "^fan@[0-2]":
>       type: object
>       $ref: fan-common.yaml#
>       unevaluatedProperties: false
> 
> Signed-off-by: Naresh Solanki <naresh.solanki@9elements.com>
> Signed-off-by: Billy Tsai <billy_tsai@aspeedtech.com>
> ---
>  .../devicetree/bindings/hwmon/fan-common.yaml | 78 +++++++++++++++++++
>  1 file changed, 78 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/hwmon/fan-common.yaml

Looking pretty good to me. It's disappointing that no one else 
interested in upstreaming their fan controller can be bothered to 
comment.

> 
> diff --git a/Documentation/devicetree/bindings/hwmon/fan-common.yaml b/Documentation/devicetree/bindings/hwmon/fan-common.yaml
> new file mode 100644
> index 000000000000..be4ce3bd7f22
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/hwmon/fan-common.yaml
> @@ -0,0 +1,78 @@
> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/hwmon/fan-common.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Common Fan Properties
> +
> +maintainers:
> +  - Naresh Solanki <naresh.solanki@9elements.com>
> +  - Billy Tsai <billy_tsai@aspeedtech.com>
> +
> +properties:
> +  max-rpm:
> +    description:
> +      Max RPM supported by fan.
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    maximum: 100000
> +
> +  min-rpm:
> +    description:
> +      Min RPM supported by fan.
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    maximum: 1000
> +
> +  pulses-per-revolution:
> +    description:
> +      The number of pulse from fan sensor per revolution.
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    maximum: 4
> +
> +  tach-div:
> +    description:
> +      Divisor for the tach sampling clock, which determines the sensitivity of the tach pin.
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +
> +  target-rpm:
> +    description:
> +      The default desired fan speed in RPM.
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +
> +  fan-driving-mode:
> +    description:
> +      Select the driving mode of the fan.(DC, PWM and so on)
> +    $ref: /schemas/types.yaml#/definitions/string

You need to define the possible values. I assume it's:

enum:
  - dc
  - pwm
  - anything else???

With that,

Reviewed-by: Rob Herring <robh@kernel.org>

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

^ permalink raw reply	[flat|nested] 31+ messages in thread
* Re: [PATCH RESEND v10 2/3] dt-bindings: hwmon: Support Aspeed g6 PWM TACH Control
  2023-11-07 10:50   ` Billy Tsai
@ 2023-11-08 18:21     ` Rob Herring
  -1 siblings, 0 replies; 31+ messages in thread
From: Rob Herring @ 2023-11-08 18:21 UTC (permalink / raw)
  To: Billy Tsai
  Cc: jdelvare, linux, krzysztof.kozlowski+dt, joel, andrew, corbet,
	thierry.reding, u.kleine-koenig, p.zabel, naresh.solanki,
	linux-hwmon, devicetree, linux-arm-kernel, linux-aspeed,
	linux-kernel, linux-doc, linux-pwm, BMC-SW, patrick

On Tue, Nov 07, 2023 at 06:50:24PM +0800, Billy Tsai wrote:
> Document the compatible for aspeed,ast2600-pwm-tach device, which can
> support up to 16 PWM outputs and 16 fan tach input.
> 
> Signed-off-by: Billy Tsai <billy_tsai@aspeedtech.com>
> ---
>  .../bindings/hwmon/aspeed,g6-pwm-tach.yaml    | 69 +++++++++++++++++++
>  1 file changed, 69 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/hwmon/aspeed,g6-pwm-tach.yaml
> 
> diff --git a/Documentation/devicetree/bindings/hwmon/aspeed,g6-pwm-tach.yaml b/Documentation/devicetree/bindings/hwmon/aspeed,g6-pwm-tach.yaml
> new file mode 100644
> index 000000000000..c615fb10705c
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/hwmon/aspeed,g6-pwm-tach.yaml
> @@ -0,0 +1,69 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +# Copyright (C) 2023 Aspeed, Inc.
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/hwmon/aspeed,g6-pwm-tach.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: ASPEED G6 PWM and Fan Tach controller
> +
> +maintainers:
> +  - Billy Tsai <billy_tsai@aspeedtech.com>
> +
> +description: |
> +  The ASPEED PWM controller can support up to 16 PWM outputs.
> +  The ASPEED Fan Tacho controller can support up to 16 fan tach input.
> +  They are independent hardware blocks, which are different from the
> +  previous version of the ASPEED chip.
> +
> +properties:
> +  compatible:
> +    enum:
> +      - aspeed,ast2600-pwm-tach
> +
> +  reg:
> +    maxItems: 1
> +
> +  clocks:
> +    maxItems: 1
> +
> +  resets:
> +    maxItems: 1
> +
> +  "#pwm-cells":
> +    const: 3
> +
> +patternProperties:
> +  "^fan-[0-9]+$":
> +    $ref: fan-common.yaml#
> +    unevaluatedProperties: false
> +    required:
> +      - tach-ch
> +
> +required:
> +  - reg
> +  - clocks
> +  - resets
> +  - "#pwm-cells"
> +  - compatible
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/clock/aspeed-clock.h>
> +    pwm_tach: pwm-tach-controller@1e610000 {
> +      compatible = "aspeed,ast2600-pwm-tach";
> +      reg = <0x1e610000 0x100>;
> +      clocks = <&syscon ASPEED_CLK_AHB>;
> +      resets = <&syscon ASPEED_RESET_PWM>;
> +      #pwm-cells = <3>;
> +
> +      fan-0 {

I assume there's a PWM connection here? How do you know which PWM? You 
said the tach channel is independent, so it is not that.

It should not be 0 from 'fan-0' because that's just a meaningless index. 

You either need 'pwms' here or you can use 'reg' and the reg value is 
the PWM channel.

> +        tach-ch = /bits/ 8 <0x0>;
> +      };
> +
> +      fan-1 {
> +        tach-ch = /bits/ 8 <0x1 0x2>;
> +      };
> +    };
> -- 
> 2.25.1
> 

^ permalink raw reply	[flat|nested] 31+ messages in thread
* Re: [PATCH RESEND v10 2/3] dt-bindings: hwmon: Support Aspeed g6 PWM TACH Control
@ 2023-11-08 18:21     ` Rob Herring
  0 siblings, 0 replies; 31+ messages in thread
From: Rob Herring @ 2023-11-08 18:21 UTC (permalink / raw)
  To: Billy Tsai
  Cc: jdelvare, linux, krzysztof.kozlowski+dt, joel, andrew, corbet,
	thierry.reding, u.kleine-koenig, p.zabel, naresh.solanki,
	linux-hwmon, devicetree, linux-arm-kernel, linux-aspeed,
	linux-kernel, linux-doc, linux-pwm, BMC-SW, patrick

On Tue, Nov 07, 2023 at 06:50:24PM +0800, Billy Tsai wrote:
> Document the compatible for aspeed,ast2600-pwm-tach device, which can
> support up to 16 PWM outputs and 16 fan tach input.
> 
> Signed-off-by: Billy Tsai <billy_tsai@aspeedtech.com>
> ---
>  .../bindings/hwmon/aspeed,g6-pwm-tach.yaml    | 69 +++++++++++++++++++
>  1 file changed, 69 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/hwmon/aspeed,g6-pwm-tach.yaml
> 
> diff --git a/Documentation/devicetree/bindings/hwmon/aspeed,g6-pwm-tach.yaml b/Documentation/devicetree/bindings/hwmon/aspeed,g6-pwm-tach.yaml
> new file mode 100644
> index 000000000000..c615fb10705c
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/hwmon/aspeed,g6-pwm-tach.yaml
> @@ -0,0 +1,69 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +# Copyright (C) 2023 Aspeed, Inc.
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/hwmon/aspeed,g6-pwm-tach.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: ASPEED G6 PWM and Fan Tach controller
> +
> +maintainers:
> +  - Billy Tsai <billy_tsai@aspeedtech.com>
> +
> +description: |
> +  The ASPEED PWM controller can support up to 16 PWM outputs.
> +  The ASPEED Fan Tacho controller can support up to 16 fan tach input.
> +  They are independent hardware blocks, which are different from the
> +  previous version of the ASPEED chip.
> +
> +properties:
> +  compatible:
> +    enum:
> +      - aspeed,ast2600-pwm-tach
> +
> +  reg:
> +    maxItems: 1
> +
> +  clocks:
> +    maxItems: 1
> +
> +  resets:
> +    maxItems: 1
> +
> +  "#pwm-cells":
> +    const: 3
> +
> +patternProperties:
> +  "^fan-[0-9]+$":
> +    $ref: fan-common.yaml#
> +    unevaluatedProperties: false
> +    required:
> +      - tach-ch
> +
> +required:
> +  - reg
> +  - clocks
> +  - resets
> +  - "#pwm-cells"
> +  - compatible
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/clock/aspeed-clock.h>
> +    pwm_tach: pwm-tach-controller@1e610000 {
> +      compatible = "aspeed,ast2600-pwm-tach";
> +      reg = <0x1e610000 0x100>;
> +      clocks = <&syscon ASPEED_CLK_AHB>;
> +      resets = <&syscon ASPEED_RESET_PWM>;
> +      #pwm-cells = <3>;
> +
> +      fan-0 {

I assume there's a PWM connection here? How do you know which PWM? You 
said the tach channel is independent, so it is not that.

It should not be 0 from 'fan-0' because that's just a meaningless index. 

You either need 'pwms' here or you can use 'reg' and the reg value is 
the PWM channel.

> +        tach-ch = /bits/ 8 <0x0>;
> +      };
> +
> +      fan-1 {
> +        tach-ch = /bits/ 8 <0x1 0x2>;
> +      };
> +    };
> -- 
> 2.25.1
> 

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

^ permalink raw reply	[flat|nested] 31+ messages in thread
* Re: [PATCH RESEND v10 1/3] dt-bindings: hwmon: fan: Add fan binding to schema
  2023-11-08 18:16     ` Rob Herring
@ 2023-11-08 18:38       ` Guenter Roeck
  -1 siblings, 0 replies; 31+ messages in thread
From: Guenter Roeck @ 2023-11-08 18:38 UTC (permalink / raw)
  To: Rob Herring, Billy Tsai
  Cc: jdelvare, krzysztof.kozlowski+dt, joel, andrew, corbet,
	thierry.reding, u.kleine-koenig, p.zabel, naresh.solanki,
	linux-hwmon, devicetree, linux-arm-kernel, linux-aspeed,
	linux-kernel, linux-doc, linux-pwm, BMC-SW, patrick

On 11/8/23 10:16, Rob Herring wrote:
> On Tue, Nov 07, 2023 at 06:50:23PM +0800, Billy Tsai wrote:
>> From: Naresh Solanki <naresh.solanki@9elements.com>
>>
>> Add common fan properties bindings to a schema.
>>
>> Bindings for fan controllers can reference the common schema for the
>> fan
>>
>> child nodes:
>>
>>    patternProperties:
>>      "^fan@[0-2]":
>>        type: object
>>        $ref: fan-common.yaml#
>>        unevaluatedProperties: false
>>
>> Signed-off-by: Naresh Solanki <naresh.solanki@9elements.com>
>> Signed-off-by: Billy Tsai <billy_tsai@aspeedtech.com>
>> ---
>>   .../devicetree/bindings/hwmon/fan-common.yaml | 78 +++++++++++++++++++
>>   1 file changed, 78 insertions(+)
>>   create mode 100644 Documentation/devicetree/bindings/hwmon/fan-common.yaml
> 
> Looking pretty good to me. It's disappointing that no one else
> interested in upstreaming their fan controller can be bothered to
> comment.
> 

FWIW, I declined to comment since it basically looks ok to me
and because at this point I'd rather have something (whatever it is)
instead of nothing.

>>
>> diff --git a/Documentation/devicetree/bindings/hwmon/fan-common.yaml b/Documentation/devicetree/bindings/hwmon/fan-common.yaml
>> new file mode 100644
>> index 000000000000..be4ce3bd7f22
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/hwmon/fan-common.yaml
>> @@ -0,0 +1,78 @@
>> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
>> +%YAML 1.2
>> +---
>> +$id: http://devicetree.org/schemas/hwmon/fan-common.yaml#
>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: Common Fan Properties
>> +
>> +maintainers:
>> +  - Naresh Solanki <naresh.solanki@9elements.com>
>> +  - Billy Tsai <billy_tsai@aspeedtech.com>
>> +
>> +properties:
>> +  max-rpm:
>> +    description:
>> +      Max RPM supported by fan.
>> +    $ref: /schemas/types.yaml#/definitions/uint32
>> +    maximum: 100000
>> +
>> +  min-rpm:
>> +    description:
>> +      Min RPM supported by fan.
>> +    $ref: /schemas/types.yaml#/definitions/uint32
>> +    maximum: 1000
>> +
>> +  pulses-per-revolution:
>> +    description:
>> +      The number of pulse from fan sensor per revolution.
>> +    $ref: /schemas/types.yaml#/definitions/uint32
>> +    maximum: 4
>> +
>> +  tach-div:
>> +    description:
>> +      Divisor for the tach sampling clock, which determines the sensitivity of the tach pin.
>> +    $ref: /schemas/types.yaml#/definitions/uint32
>> +
>> +  target-rpm:
>> +    description:
>> +      The default desired fan speed in RPM.
>> +    $ref: /schemas/types.yaml#/definitions/uint32
>> +
>> +  fan-driving-mode:
>> +    description:
>> +      Select the driving mode of the fan.(DC, PWM and so on)
>> +    $ref: /schemas/types.yaml#/definitions/string
> 
> You need to define the possible values. I assume it's:
> 
> enum:
>    - dc
>    - pwm
>    - anything else???
> 

I am not aware of any other possible method. dc and pwm is all
I have ever seen.

Guenter

> With that,
> 
> Reviewed-by: Rob Herring <robh@kernel.org>


^ permalink raw reply	[flat|nested] 31+ messages in thread
* Re: [PATCH RESEND v10 1/3] dt-bindings: hwmon: fan: Add fan binding to schema
@ 2023-11-08 18:38       ` Guenter Roeck
  0 siblings, 0 replies; 31+ messages in thread
From: Guenter Roeck @ 2023-11-08 18:38 UTC (permalink / raw)
  To: Rob Herring, Billy Tsai
  Cc: jdelvare, krzysztof.kozlowski+dt, joel, andrew, corbet,
	thierry.reding, u.kleine-koenig, p.zabel, naresh.solanki,
	linux-hwmon, devicetree, linux-arm-kernel, linux-aspeed,
	linux-kernel, linux-doc, linux-pwm, BMC-SW, patrick

On 11/8/23 10:16, Rob Herring wrote:
> On Tue, Nov 07, 2023 at 06:50:23PM +0800, Billy Tsai wrote:
>> From: Naresh Solanki <naresh.solanki@9elements.com>
>>
>> Add common fan properties bindings to a schema.
>>
>> Bindings for fan controllers can reference the common schema for the
>> fan
>>
>> child nodes:
>>
>>    patternProperties:
>>      "^fan@[0-2]":
>>        type: object
>>        $ref: fan-common.yaml#
>>        unevaluatedProperties: false
>>
>> Signed-off-by: Naresh Solanki <naresh.solanki@9elements.com>
>> Signed-off-by: Billy Tsai <billy_tsai@aspeedtech.com>
>> ---
>>   .../devicetree/bindings/hwmon/fan-common.yaml | 78 +++++++++++++++++++
>>   1 file changed, 78 insertions(+)
>>   create mode 100644 Documentation/devicetree/bindings/hwmon/fan-common.yaml
> 
> Looking pretty good to me. It's disappointing that no one else
> interested in upstreaming their fan controller can be bothered to
> comment.
> 

FWIW, I declined to comment since it basically looks ok to me
and because at this point I'd rather have something (whatever it is)
instead of nothing.

>>
>> diff --git a/Documentation/devicetree/bindings/hwmon/fan-common.yaml b/Documentation/devicetree/bindings/hwmon/fan-common.yaml
>> new file mode 100644
>> index 000000000000..be4ce3bd7f22
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/hwmon/fan-common.yaml
>> @@ -0,0 +1,78 @@
>> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
>> +%YAML 1.2
>> +---
>> +$id: http://devicetree.org/schemas/hwmon/fan-common.yaml#
>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: Common Fan Properties
>> +
>> +maintainers:
>> +  - Naresh Solanki <naresh.solanki@9elements.com>
>> +  - Billy Tsai <billy_tsai@aspeedtech.com>
>> +
>> +properties:
>> +  max-rpm:
>> +    description:
>> +      Max RPM supported by fan.
>> +    $ref: /schemas/types.yaml#/definitions/uint32
>> +    maximum: 100000
>> +
>> +  min-rpm:
>> +    description:
>> +      Min RPM supported by fan.
>> +    $ref: /schemas/types.yaml#/definitions/uint32
>> +    maximum: 1000
>> +
>> +  pulses-per-revolution:
>> +    description:
>> +      The number of pulse from fan sensor per revolution.
>> +    $ref: /schemas/types.yaml#/definitions/uint32
>> +    maximum: 4
>> +
>> +  tach-div:
>> +    description:
>> +      Divisor for the tach sampling clock, which determines the sensitivity of the tach pin.
>> +    $ref: /schemas/types.yaml#/definitions/uint32
>> +
>> +  target-rpm:
>> +    description:
>> +      The default desired fan speed in RPM.
>> +    $ref: /schemas/types.yaml#/definitions/uint32
>> +
>> +  fan-driving-mode:
>> +    description:
>> +      Select the driving mode of the fan.(DC, PWM and so on)
>> +    $ref: /schemas/types.yaml#/definitions/string
> 
> You need to define the possible values. I assume it's:
> 
> enum:
>    - dc
>    - pwm
>    - anything else???
> 

I am not aware of any other possible method. dc and pwm is all
I have ever seen.

Guenter

> With that,
> 
> Reviewed-by: Rob Herring <robh@kernel.org>


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

^ permalink raw reply	[flat|nested] 31+ messages in thread
* Re: [PATCH RESEND v10 2/3] dt-bindings: hwmon: Support Aspeed g6 PWM TACH Control
  2023-11-08 18:21     ` Rob Herring
@ 2023-11-14  3:11       ` Billy Tsai
  -1 siblings, 0 replies; 31+ messages in thread
From: Billy Tsai @ 2023-11-14  3:11 UTC (permalink / raw)
  To: Rob Herring
  Cc: jdelvare, linux, krzysztof.kozlowski+dt, joel, andrew, corbet,
	thierry.reding, u.kleine-koenig, p.zabel, naresh.solanki,
	linux-hwmon, devicetree, linux-arm-kernel, linux-aspeed,
	linux-kernel, linux-doc, linux-pwm, BMC-SW, patrick

> > Document the compatible for aspeed,ast2600-pwm-tach device, which can
> > support up to 16 PWM outputs and 16 fan tach input.
> >
> > Signed-off-by: Billy Tsai <billy_tsai@aspeedtech.com>
> > ---
> >  .../bindings/hwmon/aspeed,g6-pwm-tach.yaml    | 69 +++++++++++++++++++
> >  1 file changed, 69 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/hwmon/aspeed,g6-pwm-tach.yaml
> >
> > diff --git a/Documentation/devicetree/bindings/hwmon/aspeed,g6-pwm-tach.yaml b/Documentation/devicetree/bindings/hwmon/aspeed,g6-pwm-tach.yaml
> > new file mode 100644
> > index 000000000000..c615fb10705c
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/hwmon/aspeed,g6-pwm-tach.yaml
> > @@ -0,0 +1,69 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > +# Copyright (C) 2023 Aspeed, Inc.
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/hwmon/aspeed,g6-pwm-tach.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: ASPEED G6 PWM and Fan Tach controller
> > +
> > +maintainers:
> > +  - Billy Tsai <billy_tsai@aspeedtech.com>
> > +
> > +description: |
> > +  The ASPEED PWM controller can support up to 16 PWM outputs.
> > +  The ASPEED Fan Tacho controller can support up to 16 fan tach input.
> > +  They are independent hardware blocks, which are different from the
> > +  previous version of the ASPEED chip.
> > +
> > +properties:
> > +  compatible:
> > +    enum:
> > +      - aspeed,ast2600-pwm-tach
> > +
> > +  reg:
> > +    maxItems: 1
> > +
> > +  clocks:
> > +    maxItems: 1
> > +
> > +  resets:
> > +    maxItems: 1
> > +
> > +  "#pwm-cells":
> > +    const: 3
> > +
> > +patternProperties:
> > +  "^fan-[0-9]+$":
> > +    $ref: fan-common.yaml#
> > +    unevaluatedProperties: false
> > +    required:
> > +      - tach-ch
> > +
> > +required:
> > +  - reg
> > +  - clocks
> > +  - resets
> > +  - "#pwm-cells"
> > +  - compatible
> > +
> > +additionalProperties: false
> > +
> > +examples:
> > +  - |
> > +    #include <dt-bindings/clock/aspeed-clock.h>
> > +    pwm_tach: pwm-tach-controller@1e610000 {
> > +      compatible = "aspeed,ast2600-pwm-tach";
> > +      reg = <0x1e610000 0x100>;
> > +      clocks = <&syscon ASPEED_CLK_AHB>;
> > +      resets = <&syscon ASPEED_RESET_PWM>;
> > +      #pwm-cells = <3>;
> > +
> > +      fan-0 {

> I assume there's a PWM connection here? How do you know which PWM? You
> said the tach channel is independent, so it is not that.

> It should not be 0 from 'fan-0' because that's just a meaningless index.

> You either need 'pwms' here or you can use 'reg' and the reg value is
> the PWM channel.

Hi Rob, this binding is used to export the PWM provider and the Fan monitor (i.e., Tach).
If the user wants to add the PWM connection for the fan, it can be done as follows:

fan0: pwm-fan0 {
        compatible = "pwm-fan";
        pwms = <&pwm_tach 0 40000 0>; 
        cooling-min-state = <0>;
        cooling-max-state = <3>;
        #cooling-cells = <2>;
        cooling-levels = <0 15 128 255>;
};

This will reuse the existing PWM fan driver (e.g., pwm-fan.c).

Thanks

Billy

> > +        tach-ch = /bits/ 8 <0x0>;
> > +      };
> > +
> > +      fan-1 {
> > +        tach-ch = /bits/ 8 <0x1 0x2>;
> > +      };
> > +    };
> > --
> > 2.25.1
> >

^ permalink raw reply	[flat|nested] 31+ messages in thread
* Re: [PATCH RESEND v10 2/3] dt-bindings: hwmon: Support Aspeed g6 PWM TACH Control
@ 2023-11-14  3:11       ` Billy Tsai
  0 siblings, 0 replies; 31+ messages in thread
From: Billy Tsai @ 2023-11-14  3:11 UTC (permalink / raw)
  To: Rob Herring
  Cc: jdelvare, linux, krzysztof.kozlowski+dt, joel, andrew, corbet,
	thierry.reding, u.kleine-koenig, p.zabel, naresh.solanki,
	linux-hwmon, devicetree, linux-arm-kernel, linux-aspeed,
	linux-kernel, linux-doc, linux-pwm, BMC-SW, patrick

> > Document the compatible for aspeed,ast2600-pwm-tach device, which can
> > support up to 16 PWM outputs and 16 fan tach input.
> >
> > Signed-off-by: Billy Tsai <billy_tsai@aspeedtech.com>
> > ---
> >  .../bindings/hwmon/aspeed,g6-pwm-tach.yaml    | 69 +++++++++++++++++++
> >  1 file changed, 69 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/hwmon/aspeed,g6-pwm-tach.yaml
> >
> > diff --git a/Documentation/devicetree/bindings/hwmon/aspeed,g6-pwm-tach.yaml b/Documentation/devicetree/bindings/hwmon/aspeed,g6-pwm-tach.yaml
> > new file mode 100644
> > index 000000000000..c615fb10705c
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/hwmon/aspeed,g6-pwm-tach.yaml
> > @@ -0,0 +1,69 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > +# Copyright (C) 2023 Aspeed, Inc.
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/hwmon/aspeed,g6-pwm-tach.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: ASPEED G6 PWM and Fan Tach controller
> > +
> > +maintainers:
> > +  - Billy Tsai <billy_tsai@aspeedtech.com>
> > +
> > +description: |
> > +  The ASPEED PWM controller can support up to 16 PWM outputs.
> > +  The ASPEED Fan Tacho controller can support up to 16 fan tach input.
> > +  They are independent hardware blocks, which are different from the
> > +  previous version of the ASPEED chip.
> > +
> > +properties:
> > +  compatible:
> > +    enum:
> > +      - aspeed,ast2600-pwm-tach
> > +
> > +  reg:
> > +    maxItems: 1
> > +
> > +  clocks:
> > +    maxItems: 1
> > +
> > +  resets:
> > +    maxItems: 1
> > +
> > +  "#pwm-cells":
> > +    const: 3
> > +
> > +patternProperties:
> > +  "^fan-[0-9]+$":
> > +    $ref: fan-common.yaml#
> > +    unevaluatedProperties: false
> > +    required:
> > +      - tach-ch
> > +
> > +required:
> > +  - reg
> > +  - clocks
> > +  - resets
> > +  - "#pwm-cells"
> > +  - compatible
> > +
> > +additionalProperties: false
> > +
> > +examples:
> > +  - |
> > +    #include <dt-bindings/clock/aspeed-clock.h>
> > +    pwm_tach: pwm-tach-controller@1e610000 {
> > +      compatible = "aspeed,ast2600-pwm-tach";
> > +      reg = <0x1e610000 0x100>;
> > +      clocks = <&syscon ASPEED_CLK_AHB>;
> > +      resets = <&syscon ASPEED_RESET_PWM>;
> > +      #pwm-cells = <3>;
> > +
> > +      fan-0 {

> I assume there's a PWM connection here? How do you know which PWM? You
> said the tach channel is independent, so it is not that.

> It should not be 0 from 'fan-0' because that's just a meaningless index.

> You either need 'pwms' here or you can use 'reg' and the reg value is
> the PWM channel.

Hi Rob, this binding is used to export the PWM provider and the Fan monitor (i.e., Tach).
If the user wants to add the PWM connection for the fan, it can be done as follows:

fan0: pwm-fan0 {
        compatible = "pwm-fan";
        pwms = <&pwm_tach 0 40000 0>; 
        cooling-min-state = <0>;
        cooling-max-state = <3>;
        #cooling-cells = <2>;
        cooling-levels = <0 15 128 255>;
};

This will reuse the existing PWM fan driver (e.g., pwm-fan.c).

Thanks

Billy

> > +        tach-ch = /bits/ 8 <0x0>;
> > +      };
> > +
> > +      fan-1 {
> > +        tach-ch = /bits/ 8 <0x1 0x2>;
> > +      };
> > +    };
> > --
> > 2.25.1
> >

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

^ permalink raw reply	[flat|nested] 31+ messages in thread
* Re: [PATCH RESEND v10 2/3] dt-bindings: hwmon: Support Aspeed g6 PWM TACH Control
  2023-11-14  3:11       ` Billy Tsai
@ 2023-11-22 20:47         ` Rob Herring
  -1 siblings, 0 replies; 31+ messages in thread
From: Rob Herring @ 2023-11-22 20:47 UTC (permalink / raw)
  To: Billy Tsai
  Cc: jdelvare, linux, krzysztof.kozlowski+dt, joel, andrew, corbet,
	thierry.reding, u.kleine-koenig, p.zabel, naresh.solanki,
	linux-hwmon, devicetree, linux-arm-kernel, linux-aspeed,
	linux-kernel, linux-doc, linux-pwm, BMC-SW, patrick

On Mon, Nov 13, 2023 at 8:11 PM Billy Tsai <billy_tsai@aspeedtech.com> wrote:
>
> > > Document the compatible for aspeed,ast2600-pwm-tach device, which can
> > > support up to 16 PWM outputs and 16 fan tach input.
> > >
> > > Signed-off-by: Billy Tsai <billy_tsai@aspeedtech.com>
> > > ---
> > >  .../bindings/hwmon/aspeed,g6-pwm-tach.yaml    | 69 +++++++++++++++++++
> > >  1 file changed, 69 insertions(+)
> > >  create mode 100644 Documentation/devicetree/bindings/hwmon/aspeed,g6-pwm-tach.yaml
> > >
> > > diff --git a/Documentation/devicetree/bindings/hwmon/aspeed,g6-pwm-tach.yaml b/Documentation/devicetree/bindings/hwmon/aspeed,g6-pwm-tach.yaml
> > > new file mode 100644
> > > index 000000000000..c615fb10705c
> > > --- /dev/null
> > > +++ b/Documentation/devicetree/bindings/hwmon/aspeed,g6-pwm-tach.yaml
> > > @@ -0,0 +1,69 @@
> > > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > > +# Copyright (C) 2023 Aspeed, Inc.
> > > +%YAML 1.2
> > > +---
> > > +$id: http://devicetree.org/schemas/hwmon/aspeed,g6-pwm-tach.yaml#
> > > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > > +
> > > +title: ASPEED G6 PWM and Fan Tach controller
> > > +
> > > +maintainers:
> > > +  - Billy Tsai <billy_tsai@aspeedtech.com>
> > > +
> > > +description: |
> > > +  The ASPEED PWM controller can support up to 16 PWM outputs.
> > > +  The ASPEED Fan Tacho controller can support up to 16 fan tach input.
> > > +  They are independent hardware blocks, which are different from the
> > > +  previous version of the ASPEED chip.
> > > +
> > > +properties:
> > > +  compatible:
> > > +    enum:
> > > +      - aspeed,ast2600-pwm-tach
> > > +
> > > +  reg:
> > > +    maxItems: 1
> > > +
> > > +  clocks:
> > > +    maxItems: 1
> > > +
> > > +  resets:
> > > +    maxItems: 1
> > > +
> > > +  "#pwm-cells":
> > > +    const: 3
> > > +
> > > +patternProperties:
> > > +  "^fan-[0-9]+$":
> > > +    $ref: fan-common.yaml#
> > > +    unevaluatedProperties: false
> > > +    required:
> > > +      - tach-ch
> > > +
> > > +required:
> > > +  - reg
> > > +  - clocks
> > > +  - resets
> > > +  - "#pwm-cells"
> > > +  - compatible
> > > +
> > > +additionalProperties: false
> > > +
> > > +examples:
> > > +  - |
> > > +    #include <dt-bindings/clock/aspeed-clock.h>
> > > +    pwm_tach: pwm-tach-controller@1e610000 {
> > > +      compatible = "aspeed,ast2600-pwm-tach";
> > > +      reg = <0x1e610000 0x100>;
> > > +      clocks = <&syscon ASPEED_CLK_AHB>;
> > > +      resets = <&syscon ASPEED_RESET_PWM>;
> > > +      #pwm-cells = <3>;
> > > +
> > > +      fan-0 {
>
> > I assume there's a PWM connection here? How do you know which PWM? You
> > said the tach channel is independent, so it is not that.
>
> > It should not be 0 from 'fan-0' because that's just a meaningless index.
>
> > You either need 'pwms' here or you can use 'reg' and the reg value is
> > the PWM channel.
>
> Hi Rob, this binding is used to export the PWM provider and the Fan monitor (i.e., Tach).
> If the user wants to add the PWM connection for the fan, it can be done as follows:
>
> fan0: pwm-fan0 {
>         compatible = "pwm-fan";
>         pwms = <&pwm_tach 0 40000 0>;
>         cooling-min-state = <0>;
>         cooling-max-state = <3>;
>         #cooling-cells = <2>;
>         cooling-levels = <0 15 128 255>;
> };
>
> This will reuse the existing PWM fan driver (e.g., pwm-fan.c).

I'm confused now. So what are the child nodes you have? You are
defining the fan in 2 places? The "pwm-fan" driver supports a tach via
an interrupt, so how would this work in your case?

Rob

^ permalink raw reply	[flat|nested] 31+ messages in thread
* Re: [PATCH RESEND v10 2/3] dt-bindings: hwmon: Support Aspeed g6 PWM TACH Control
@ 2023-11-22 20:47         ` Rob Herring
  0 siblings, 0 replies; 31+ messages in thread
From: Rob Herring @ 2023-11-22 20:47 UTC (permalink / raw)
  To: Billy Tsai
  Cc: jdelvare, linux, krzysztof.kozlowski+dt, joel, andrew, corbet,
	thierry.reding, u.kleine-koenig, p.zabel, naresh.solanki,
	linux-hwmon, devicetree, linux-arm-kernel, linux-aspeed,
	linux-kernel, linux-doc, linux-pwm, BMC-SW, patrick

On Mon, Nov 13, 2023 at 8:11 PM Billy Tsai <billy_tsai@aspeedtech.com> wrote:
>
> > > Document the compatible for aspeed,ast2600-pwm-tach device, which can
> > > support up to 16 PWM outputs and 16 fan tach input.
> > >
> > > Signed-off-by: Billy Tsai <billy_tsai@aspeedtech.com>
> > > ---
> > >  .../bindings/hwmon/aspeed,g6-pwm-tach.yaml    | 69 +++++++++++++++++++
> > >  1 file changed, 69 insertions(+)
> > >  create mode 100644 Documentation/devicetree/bindings/hwmon/aspeed,g6-pwm-tach.yaml
> > >
> > > diff --git a/Documentation/devicetree/bindings/hwmon/aspeed,g6-pwm-tach.yaml b/Documentation/devicetree/bindings/hwmon/aspeed,g6-pwm-tach.yaml
> > > new file mode 100644
> > > index 000000000000..c615fb10705c
> > > --- /dev/null
> > > +++ b/Documentation/devicetree/bindings/hwmon/aspeed,g6-pwm-tach.yaml
> > > @@ -0,0 +1,69 @@
> > > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > > +# Copyright (C) 2023 Aspeed, Inc.
> > > +%YAML 1.2
> > > +---
> > > +$id: http://devicetree.org/schemas/hwmon/aspeed,g6-pwm-tach.yaml#
> > > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > > +
> > > +title: ASPEED G6 PWM and Fan Tach controller
> > > +
> > > +maintainers:
> > > +  - Billy Tsai <billy_tsai@aspeedtech.com>
> > > +
> > > +description: |
> > > +  The ASPEED PWM controller can support up to 16 PWM outputs.
> > > +  The ASPEED Fan Tacho controller can support up to 16 fan tach input.
> > > +  They are independent hardware blocks, which are different from the
> > > +  previous version of the ASPEED chip.
> > > +
> > > +properties:
> > > +  compatible:
> > > +    enum:
> > > +      - aspeed,ast2600-pwm-tach
> > > +
> > > +  reg:
> > > +    maxItems: 1
> > > +
> > > +  clocks:
> > > +    maxItems: 1
> > > +
> > > +  resets:
> > > +    maxItems: 1
> > > +
> > > +  "#pwm-cells":
> > > +    const: 3
> > > +
> > > +patternProperties:
> > > +  "^fan-[0-9]+$":
> > > +    $ref: fan-common.yaml#
> > > +    unevaluatedProperties: false
> > > +    required:
> > > +      - tach-ch
> > > +
> > > +required:
> > > +  - reg
> > > +  - clocks
> > > +  - resets
> > > +  - "#pwm-cells"
> > > +  - compatible
> > > +
> > > +additionalProperties: false
> > > +
> > > +examples:
> > > +  - |
> > > +    #include <dt-bindings/clock/aspeed-clock.h>
> > > +    pwm_tach: pwm-tach-controller@1e610000 {
> > > +      compatible = "aspeed,ast2600-pwm-tach";
> > > +      reg = <0x1e610000 0x100>;
> > > +      clocks = <&syscon ASPEED_CLK_AHB>;
> > > +      resets = <&syscon ASPEED_RESET_PWM>;
> > > +      #pwm-cells = <3>;
> > > +
> > > +      fan-0 {
>
> > I assume there's a PWM connection here? How do you know which PWM? You
> > said the tach channel is independent, so it is not that.
>
> > It should not be 0 from 'fan-0' because that's just a meaningless index.
>
> > You either need 'pwms' here or you can use 'reg' and the reg value is
> > the PWM channel.
>
> Hi Rob, this binding is used to export the PWM provider and the Fan monitor (i.e., Tach).
> If the user wants to add the PWM connection for the fan, it can be done as follows:
>
> fan0: pwm-fan0 {
>         compatible = "pwm-fan";
>         pwms = <&pwm_tach 0 40000 0>;
>         cooling-min-state = <0>;
>         cooling-max-state = <3>;
>         #cooling-cells = <2>;
>         cooling-levels = <0 15 128 255>;
> };
>
> This will reuse the existing PWM fan driver (e.g., pwm-fan.c).

I'm confused now. So what are the child nodes you have? You are
defining the fan in 2 places? The "pwm-fan" driver supports a tach via
an interrupt, so how would this work in your case?

Rob

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

^ permalink raw reply	[flat|nested] 31+ messages in thread
* Re: [PATCH RESEND v10 2/3] dt-bindings: hwmon: Support Aspeed g6 PWM TACH Control
  2023-11-22 20:47         ` Rob Herring
@ 2023-11-27  5:45           ` Billy Tsai
  -1 siblings, 0 replies; 31+ messages in thread
From: Billy Tsai @ 2023-11-27  5:45 UTC (permalink / raw)
  To: Rob Herring
  Cc: jdelvare, linux, krzysztof.kozlowski+dt, joel, andrew, corbet,
	thierry.reding, u.kleine-koenig, p.zabel, naresh.solanki,
	linux-hwmon, devicetree, linux-arm-kernel, linux-aspeed,
	linux-kernel, linux-doc, linux-pwm, BMC-SW, patrick

> > > > Document the compatible for aspeed,ast2600-pwm-tach device, which can
> > > > support up to 16 PWM outputs and 16 fan tach input.
> > > >
> > > > Signed-off-by: Billy Tsai <billy_tsai@aspeedtech.com>
> > > > ---
> > > >  .../bindings/hwmon/aspeed,g6-pwm-tach.yaml    | 69 +++++++++++++++++++
> > > >  1 file changed, 69 insertions(+)
> > > >  create mode 100644 Documentation/devicetree/bindings/hwmon/aspeed,g6-pwm-tach.yaml
> > > >
> > > > diff --git a/Documentation/devicetree/bindings/hwmon/aspeed,g6-pwm-tach.yaml b/Documentation/devicetree/bindings/hwmon/aspeed,g6-pwm-tach.yaml
> > > > new file mode 100644
> > > > index 000000000000..c615fb10705c
> > > > --- /dev/null
> > > > +++ b/Documentation/devicetree/bindings/hwmon/aspeed,g6-pwm-tach.yaml
> > > > @@ -0,0 +1,69 @@
> > > > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > > > +# Copyright (C) 2023 Aspeed, Inc.
> > > > +%YAML 1.2
> > > > +---
> > > > +$id: http://devicetree.org/schemas/hwmon/aspeed,g6-pwm-tach.yaml#
> > > > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > > > +
> > > > +title: ASPEED G6 PWM and Fan Tach controller
> > > > +
> > > > +maintainers:
> > > > +  - Billy Tsai <billy_tsai@aspeedtech.com>
> > > > +
> > > > +description: |
> > > > +  The ASPEED PWM controller can support up to 16 PWM outputs.
> > > > +  The ASPEED Fan Tacho controller can support up to 16 fan tach input.
> > > > +  They are independent hardware blocks, which are different from the
> > > > +  previous version of the ASPEED chip.
> > > > +
> > > > +properties:
> > > > +  compatible:
> > > > +    enum:
> > > > +      - aspeed,ast2600-pwm-tach
> > > > +
> > > > +  reg:
> > > > +    maxItems: 1
> > > > +
> > > > +  clocks:
> > > > +    maxItems: 1
> > > > +
> > > > +  resets:
> > > > +    maxItems: 1
> > > > +
> > > > +  "#pwm-cells":
> > > > +    const: 3
> > > > +
> > > > +patternProperties:
> > > > +  "^fan-[0-9]+$":
> > > > +    $ref: fan-common.yaml#
> > > > +    unevaluatedProperties: false
> > > > +    required:
> > > > +      - tach-ch
> > > > +
> > > > +required:
> > > > +  - reg
> > > > +  - clocks
> > > > +  - resets
> > > > +  - "#pwm-cells"
> > > > +  - compatible
> > > > +
> > > > +additionalProperties: false
> > > > +
> > > > +examples:
> > > > +  - |
> > > > +    #include <dt-bindings/clock/aspeed-clock.h>
> > > > +    pwm_tach: pwm-tach-controller@1e610000 {
> > > > +      compatible = "aspeed,ast2600-pwm-tach";
> > > > +      reg = <0x1e610000 0x100>;
> > > > +      clocks = <&syscon ASPEED_CLK_AHB>;
> > > > +      resets = <&syscon ASPEED_RESET_PWM>;
> > > > +      #pwm-cells = <3>;
> > > > +
> > > > +      fan-0 {
> >
> > > I assume there's a PWM connection here? How do you know which PWM? You
> > > said the tach channel is independent, so it is not that.
> >
> > > It should not be 0 from 'fan-0' because that's just a meaningless index.
> >
> > > You either need 'pwms' here or you can use 'reg' and the reg value is
> > > the PWM channel.
> >
> > Hi Rob, this binding is used to export the PWM provider and the Fan monitor (i.e., Tach).
> > If the user wants to add the PWM connection for the fan, it can be done as follows:
> >
> > fan0: pwm-fan0 {
> >         compatible = "pwm-fan";
> >         pwms = <&pwm_tach 0 40000 0>;
> >         cooling-min-state = <0>;
> >         cooling-max-state = <3>;
> >         #cooling-cells = <2>;
> >         cooling-levels = <0 15 128 255>;
> > };
> >
> > This will reuse the existing PWM fan driver (e.g., pwm-fan.c).

> I'm confused now. So what are the child nodes you have? You are
> defining the fan in 2 places? The "pwm-fan" driver supports a tach via
> an interrupt, so how would this work in your case?

Hi Rob,

The tach interrupt for the pwm-fan is option. In our case, the dts just reuse the pwm control function
of the pwm-fan, and the part of the tach monitor will be created by our fan child nodes.
So the dts will like followings:

// Use to declare the tach monitor for fan.
&pwm_tach {
        fan-0 {
		tach-ch = /bits/ 8 <0x0>;
	};
	fan-1 {
		tach-ch = /bits/ 8 <0x1>;
	};
        ...
}

// Reuse the pwm-fan.c to control the behavior of the PWM for fan.
fan0: pwm-fan0 {
        compatible = "pwm-fan";
        pwms = <&pwm_tach 0 40000 0>;   /* Target freq:25 kHz */
        cooling-min-state = <0>;
        cooling-max-state = <3>;
        #cooling-cells = <2>;
        cooling-levels = <0 15 128 255>;
};

fan1: pwm-fan1 {
        compatible = "pwm-fan";
        pwms = <&pwm_tach 1 40000 0>;   /* Target freq:25 kHz */
        cooling-min-state = <0>;
        cooling-max-state = <3>;
        #cooling-cells = <2>;
        cooling-levels = <0 15 128 255>;
};

Thanks

^ permalink raw reply	[flat|nested] 31+ messages in thread
* Re: [PATCH RESEND v10 2/3] dt-bindings: hwmon: Support Aspeed g6 PWM TACH Control
@ 2023-11-27  5:45           ` Billy Tsai
  0 siblings, 0 replies; 31+ messages in thread
From: Billy Tsai @ 2023-11-27  5:45 UTC (permalink / raw)
  To: Rob Herring
  Cc: jdelvare, linux, krzysztof.kozlowski+dt, joel, andrew, corbet,
	thierry.reding, u.kleine-koenig, p.zabel, naresh.solanki,
	linux-hwmon, devicetree, linux-arm-kernel, linux-aspeed,
	linux-kernel, linux-doc, linux-pwm, BMC-SW, patrick

> > > > Document the compatible for aspeed,ast2600-pwm-tach device, which can
> > > > support up to 16 PWM outputs and 16 fan tach input.
> > > >
> > > > Signed-off-by: Billy Tsai <billy_tsai@aspeedtech.com>
> > > > ---
> > > >  .../bindings/hwmon/aspeed,g6-pwm-tach.yaml    | 69 +++++++++++++++++++
> > > >  1 file changed, 69 insertions(+)
> > > >  create mode 100644 Documentation/devicetree/bindings/hwmon/aspeed,g6-pwm-tach.yaml
> > > >
> > > > diff --git a/Documentation/devicetree/bindings/hwmon/aspeed,g6-pwm-tach.yaml b/Documentation/devicetree/bindings/hwmon/aspeed,g6-pwm-tach.yaml
> > > > new file mode 100644
> > > > index 000000000000..c615fb10705c
> > > > --- /dev/null
> > > > +++ b/Documentation/devicetree/bindings/hwmon/aspeed,g6-pwm-tach.yaml
> > > > @@ -0,0 +1,69 @@
> > > > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > > > +# Copyright (C) 2023 Aspeed, Inc.
> > > > +%YAML 1.2
> > > > +---
> > > > +$id: http://devicetree.org/schemas/hwmon/aspeed,g6-pwm-tach.yaml#
> > > > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > > > +
> > > > +title: ASPEED G6 PWM and Fan Tach controller
> > > > +
> > > > +maintainers:
> > > > +  - Billy Tsai <billy_tsai@aspeedtech.com>
> > > > +
> > > > +description: |
> > > > +  The ASPEED PWM controller can support up to 16 PWM outputs.
> > > > +  The ASPEED Fan Tacho controller can support up to 16 fan tach input.
> > > > +  They are independent hardware blocks, which are different from the
> > > > +  previous version of the ASPEED chip.
> > > > +
> > > > +properties:
> > > > +  compatible:
> > > > +    enum:
> > > > +      - aspeed,ast2600-pwm-tach
> > > > +
> > > > +  reg:
> > > > +    maxItems: 1
> > > > +
> > > > +  clocks:
> > > > +    maxItems: 1
> > > > +
> > > > +  resets:
> > > > +    maxItems: 1
> > > > +
> > > > +  "#pwm-cells":
> > > > +    const: 3
> > > > +
> > > > +patternProperties:
> > > > +  "^fan-[0-9]+$":
> > > > +    $ref: fan-common.yaml#
> > > > +    unevaluatedProperties: false
> > > > +    required:
> > > > +      - tach-ch
> > > > +
> > > > +required:
> > > > +  - reg
> > > > +  - clocks
> > > > +  - resets
> > > > +  - "#pwm-cells"
> > > > +  - compatible
> > > > +
> > > > +additionalProperties: false
> > > > +
> > > > +examples:
> > > > +  - |
> > > > +    #include <dt-bindings/clock/aspeed-clock.h>
> > > > +    pwm_tach: pwm-tach-controller@1e610000 {
> > > > +      compatible = "aspeed,ast2600-pwm-tach";
> > > > +      reg = <0x1e610000 0x100>;
> > > > +      clocks = <&syscon ASPEED_CLK_AHB>;
> > > > +      resets = <&syscon ASPEED_RESET_PWM>;
> > > > +      #pwm-cells = <3>;
> > > > +
> > > > +      fan-0 {
> >
> > > I assume there's a PWM connection here? How do you know which PWM? You
> > > said the tach channel is independent, so it is not that.
> >
> > > It should not be 0 from 'fan-0' because that's just a meaningless index.
> >
> > > You either need 'pwms' here or you can use 'reg' and the reg value is
> > > the PWM channel.
> >
> > Hi Rob, this binding is used to export the PWM provider and the Fan monitor (i.e., Tach).
> > If the user wants to add the PWM connection for the fan, it can be done as follows:
> >
> > fan0: pwm-fan0 {
> >         compatible = "pwm-fan";
> >         pwms = <&pwm_tach 0 40000 0>;
> >         cooling-min-state = <0>;
> >         cooling-max-state = <3>;
> >         #cooling-cells = <2>;
> >         cooling-levels = <0 15 128 255>;
> > };
> >
> > This will reuse the existing PWM fan driver (e.g., pwm-fan.c).

> I'm confused now. So what are the child nodes you have? You are
> defining the fan in 2 places? The "pwm-fan" driver supports a tach via
> an interrupt, so how would this work in your case?

Hi Rob,

The tach interrupt for the pwm-fan is option. In our case, the dts just reuse the pwm control function
of the pwm-fan, and the part of the tach monitor will be created by our fan child nodes.
So the dts will like followings:

// Use to declare the tach monitor for fan.
&pwm_tach {
        fan-0 {
		tach-ch = /bits/ 8 <0x0>;
	};
	fan-1 {
		tach-ch = /bits/ 8 <0x1>;
	};
        ...
}

// Reuse the pwm-fan.c to control the behavior of the PWM for fan.
fan0: pwm-fan0 {
        compatible = "pwm-fan";
        pwms = <&pwm_tach 0 40000 0>;   /* Target freq:25 kHz */
        cooling-min-state = <0>;
        cooling-max-state = <3>;
        #cooling-cells = <2>;
        cooling-levels = <0 15 128 255>;
};

fan1: pwm-fan1 {
        compatible = "pwm-fan";
        pwms = <&pwm_tach 1 40000 0>;   /* Target freq:25 kHz */
        cooling-min-state = <0>;
        cooling-max-state = <3>;
        #cooling-cells = <2>;
        cooling-levels = <0 15 128 255>;
};

Thanks
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

^ permalink raw reply	[flat|nested] 31+ messages in thread
* Re: [PATCH RESEND v10 0/3] Support pwm/tach driver for aspeed ast26xx
  2023-11-07 19:02   ` Guenter Roeck
@ 2023-12-06 17:48     ` Uwe Kleine-König
  -1 siblings, 0 replies; 31+ messages in thread
From: Uwe Kleine-König @ 2023-12-06 17:48 UTC (permalink / raw)
  To: Guenter Roeck
  Cc: Billy Tsai, jdelvare, robh+dt, krzysztof.kozlowski+dt, joel,
	andrew, corbet, thierry.reding, p.zabel, naresh.solanki,
	linux-hwmon, devicetree, linux-arm-kernel, linux-aspeed,
	linux-kernel, linux-doc, linux-pwm, BMC-SW, patrick

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On Tue, Nov 07, 2023 at 11:02:43AM -0800, Guenter Roeck wrote:
> On 11/7/23 02:50, Billy Tsai wrote:
> > Unlike the old design that the register setting of the TACH should based
> > on the configure of the PWM. In ast26xx, the dependency between pwm and
> > tach controller is eliminated and becomes a separate hardware block. One
> > is used to provide pwm output and another is used to monitor the frequency
> > of the input. This driver implements them by exposing two kernel
> > subsystems: PWM and HWMON. The PWM subsystem can be utilized alongside
> > existing drivers for controlling elements such as fans (pwm-fan.c),
> > beepers (pwm-beeper.c) and so on. Through the HWMON subsystem, the driver
> > provides sysfs interfaces for fan.
> > 
> > Changes since v9:
> > Change the type of fan-driving-mode to string
> > Fix some typos and formatting issues.
> > 
> 
> What is the resend about ?

And to the original v10 there is a reply by Krzysztof;
see https://lore.kernel.org/linux-pwm/3d9e50db-19f0-43b3-8042-2f80a1e7b79e@linaro.org/ .

I'll mark the original and this resend as "changes-requested" in our
patchwork. Probably the most cooperative way to object is to send a v11
and point out the changes compared to v10.

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | https://www.pengutronix.de/ |

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^ permalink raw reply	[flat|nested] 31+ messages in thread
* Re: [PATCH RESEND v10 0/3] Support pwm/tach driver for aspeed ast26xx
@ 2023-12-06 17:48     ` Uwe Kleine-König
  0 siblings, 0 replies; 31+ messages in thread
From: Uwe Kleine-König @ 2023-12-06 17:48 UTC (permalink / raw)
  To: Guenter Roeck
  Cc: Billy Tsai, jdelvare, robh+dt, krzysztof.kozlowski+dt, joel,
	andrew, corbet, thierry.reding, p.zabel, naresh.solanki,
	linux-hwmon, devicetree, linux-arm-kernel, linux-aspeed,
	linux-kernel, linux-doc, linux-pwm, BMC-SW, patrick


[-- Attachment #1.1: Type: text/plain, Size: 1434 bytes --]

On Tue, Nov 07, 2023 at 11:02:43AM -0800, Guenter Roeck wrote:
> On 11/7/23 02:50, Billy Tsai wrote:
> > Unlike the old design that the register setting of the TACH should based
> > on the configure of the PWM. In ast26xx, the dependency between pwm and
> > tach controller is eliminated and becomes a separate hardware block. One
> > is used to provide pwm output and another is used to monitor the frequency
> > of the input. This driver implements them by exposing two kernel
> > subsystems: PWM and HWMON. The PWM subsystem can be utilized alongside
> > existing drivers for controlling elements such as fans (pwm-fan.c),
> > beepers (pwm-beeper.c) and so on. Through the HWMON subsystem, the driver
> > provides sysfs interfaces for fan.
> > 
> > Changes since v9:
> > Change the type of fan-driving-mode to string
> > Fix some typos and formatting issues.
> > 
> 
> What is the resend about ?

And to the original v10 there is a reply by Krzysztof;
see https://lore.kernel.org/linux-pwm/3d9e50db-19f0-43b3-8042-2f80a1e7b79e@linaro.org/ .

I'll mark the original and this resend as "changes-requested" in our
patchwork. Probably the most cooperative way to object is to send a v11
and point out the changes compared to v10.

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | https://www.pengutronix.de/ |

[-- Attachment #1.2: signature.asc --]
[-- Type: application/pgp-signature, Size: 488 bytes --]

[-- Attachment #2: Type: text/plain, Size: 176 bytes --]

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

^ permalink raw reply	[flat|nested] 31+ messages in thread
* Re: [PATCH RESEND v10 0/3] Support pwm/tach driver for aspeed ast26xx
  2023-12-06 17:48     ` Uwe Kleine-König
@ 2023-12-06 17:56       ` Krzysztof Kozlowski
  -1 siblings, 0 replies; 31+ messages in thread
From: Krzysztof Kozlowski @ 2023-12-06 17:56 UTC (permalink / raw)
  To: Uwe Kleine-König, Guenter Roeck
  Cc: Billy Tsai, jdelvare, robh+dt, krzysztof.kozlowski+dt, joel,
	andrew, corbet, thierry.reding, p.zabel, naresh.solanki,
	linux-hwmon, devicetree, linux-arm-kernel, linux-aspeed,
	linux-kernel, linux-doc, linux-pwm, BMC-SW, patrick

On 06/12/2023 18:48, Uwe Kleine-König wrote:
> On Tue, Nov 07, 2023 at 11:02:43AM -0800, Guenter Roeck wrote:
>> On 11/7/23 02:50, Billy Tsai wrote:
>>> Unlike the old design that the register setting of the TACH should based
>>> on the configure of the PWM. In ast26xx, the dependency between pwm and
>>> tach controller is eliminated and becomes a separate hardware block. One
>>> is used to provide pwm output and another is used to monitor the frequency
>>> of the input. This driver implements them by exposing two kernel
>>> subsystems: PWM and HWMON. The PWM subsystem can be utilized alongside
>>> existing drivers for controlling elements such as fans (pwm-fan.c),
>>> beepers (pwm-beeper.c) and so on. Through the HWMON subsystem, the driver
>>> provides sysfs interfaces for fan.
>>>
>>> Changes since v9:
>>> Change the type of fan-driving-mode to string
>>> Fix some typos and formatting issues.
>>>
>>
>> What is the resend about ?
> 
> And to the original v10 there is a reply by Krzysztof;
> see https://lore.kernel.org/linux-pwm/3d9e50db-19f0-43b3-8042-2f80a1e7b79e@linaro.org/ .
> 
> I'll mark the original and this resend as "changes-requested" in our
> patchwork. Probably the most cooperative way to object is to send a v11
> and point out the changes compared to v10.

The resend might be fixing issues from v10, but who knows which and how
many. In any case it should be v11, not a resend.

Best regards,
Krzysztof


^ permalink raw reply	[flat|nested] 31+ messages in thread
* Re: [PATCH RESEND v10 0/3] Support pwm/tach driver for aspeed ast26xx
@ 2023-12-06 17:56       ` Krzysztof Kozlowski
  0 siblings, 0 replies; 31+ messages in thread
From: Krzysztof Kozlowski @ 2023-12-06 17:56 UTC (permalink / raw)
  To: Uwe Kleine-König, Guenter Roeck
  Cc: Billy Tsai, jdelvare, robh+dt, krzysztof.kozlowski+dt, joel,
	andrew, corbet, thierry.reding, p.zabel, naresh.solanki,
	linux-hwmon, devicetree, linux-arm-kernel, linux-aspeed,
	linux-kernel, linux-doc, linux-pwm, BMC-SW, patrick

On 06/12/2023 18:48, Uwe Kleine-König wrote:
> On Tue, Nov 07, 2023 at 11:02:43AM -0800, Guenter Roeck wrote:
>> On 11/7/23 02:50, Billy Tsai wrote:
>>> Unlike the old design that the register setting of the TACH should based
>>> on the configure of the PWM. In ast26xx, the dependency between pwm and
>>> tach controller is eliminated and becomes a separate hardware block. One
>>> is used to provide pwm output and another is used to monitor the frequency
>>> of the input. This driver implements them by exposing two kernel
>>> subsystems: PWM and HWMON. The PWM subsystem can be utilized alongside
>>> existing drivers for controlling elements such as fans (pwm-fan.c),
>>> beepers (pwm-beeper.c) and so on. Through the HWMON subsystem, the driver
>>> provides sysfs interfaces for fan.
>>>
>>> Changes since v9:
>>> Change the type of fan-driving-mode to string
>>> Fix some typos and formatting issues.
>>>
>>
>> What is the resend about ?
> 
> And to the original v10 there is a reply by Krzysztof;
> see https://lore.kernel.org/linux-pwm/3d9e50db-19f0-43b3-8042-2f80a1e7b79e@linaro.org/ .
> 
> I'll mark the original and this resend as "changes-requested" in our
> patchwork. Probably the most cooperative way to object is to send a v11
> and point out the changes compared to v10.

The resend might be fixing issues from v10, but who knows which and how
many. In any case it should be v11, not a resend.

Best regards,
Krzysztof


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

^ permalink raw reply	[flat|nested] 31+ messages in thread
* Re: [PATCH RESEND v10 0/3] Support pwm/tach driver for aspeed ast26xx
  2023-12-06 17:56       ` Krzysztof Kozlowski
@ 2023-12-13  3:23         ` Billy Tsai
  -1 siblings, 0 replies; 31+ messages in thread
From: Billy Tsai @ 2023-12-13  3:23 UTC (permalink / raw)
  To: Krzysztof Kozlowski, Uwe Kleine-König, Guenter Roeck
  Cc: jdelvare, robh+dt, krzysztof.kozlowski+dt, joel, andrew, corbet,
	thierry.reding, p.zabel, naresh.solanki, linux-hwmon, devicetree,
	linux-arm-kernel, linux-aspeed, linux-kernel, linux-doc,
	linux-pwm, BMC-SW, patrick

On 06/12/2023 18:48, Uwe Kleine-König wrote:
>> On Tue, Nov 07, 2023 at 11:02:43AM -0800, Guenter Roeck wrote:
>>> On 11/7/23 02:50, Billy Tsai wrote:
>>>> Unlike the old design that the register setting of the TACH should based
>>>> on the configure of the PWM. In ast26xx, the dependency between pwm and
>>>> tach controller is eliminated and becomes a separate hardware block. One
>>>> is used to provide pwm output and another is used to monitor the frequency
>>>> of the input. This driver implements them by exposing two kernel
>>>> subsystems: PWM and HWMON. The PWM subsystem can be utilized alongside
>>>> existing drivers for controlling elements such as fans (pwm-fan.c),
>>>> beepers (pwm-beeper.c) and so on. Through the HWMON subsystem, the driver
>>>> provides sysfs interfaces for fan.
>>>>
>>>> Changes since v9:
>>>> Change the type of fan-driving-mode to string
>>>> Fix some typos and formatting issues.
>>>>
>>>
>>> What is the resend about ?
>>
>> And to the original v10 there is a reply by Krzysztof;
>> see https://lore.kernel.org/linux-pwm/3d9e50db-19f0-43b3-8042-2f80a1e7b79e@linaro.org/ .
>>
>> I'll mark the original and this resend as "changes-requested" in our
>> patchwork. Probably the most cooperative way to object is to send a v11
>> and point out the changes compared to v10.

> The resend might be fixing issues from v10, but who knows which and how
> many. In any case it should be v11, not a resend.

I apologize for responding to this question inappropriately. I only replied to Guenter and removed
the others.
The reason for the resend is simply to remove the 'Change-Id' in the commit log, which triggers an
error when running scripts/checkpatch.pl. 
It's a minor issue, and I forgot to mention this change in the cover letter.
I sincerely apologize for any confusion.

Best regards,
Billy Tsai

^ permalink raw reply	[flat|nested] 31+ messages in thread
* Re: [PATCH RESEND v10 0/3] Support pwm/tach driver for aspeed ast26xx
@ 2023-12-13  3:23         ` Billy Tsai
  0 siblings, 0 replies; 31+ messages in thread
From: Billy Tsai @ 2023-12-13  3:23 UTC (permalink / raw)
  To: Krzysztof Kozlowski, Uwe Kleine-König, Guenter Roeck
  Cc: jdelvare, robh+dt, krzysztof.kozlowski+dt, joel, andrew, corbet,
	thierry.reding, p.zabel, naresh.solanki, linux-hwmon, devicetree,
	linux-arm-kernel, linux-aspeed, linux-kernel, linux-doc,
	linux-pwm, BMC-SW, patrick

On 06/12/2023 18:48, Uwe Kleine-König wrote:
>> On Tue, Nov 07, 2023 at 11:02:43AM -0800, Guenter Roeck wrote:
>>> On 11/7/23 02:50, Billy Tsai wrote:
>>>> Unlike the old design that the register setting of the TACH should based
>>>> on the configure of the PWM. In ast26xx, the dependency between pwm and
>>>> tach controller is eliminated and becomes a separate hardware block. One
>>>> is used to provide pwm output and another is used to monitor the frequency
>>>> of the input. This driver implements them by exposing two kernel
>>>> subsystems: PWM and HWMON. The PWM subsystem can be utilized alongside
>>>> existing drivers for controlling elements such as fans (pwm-fan.c),
>>>> beepers (pwm-beeper.c) and so on. Through the HWMON subsystem, the driver
>>>> provides sysfs interfaces for fan.
>>>>
>>>> Changes since v9:
>>>> Change the type of fan-driving-mode to string
>>>> Fix some typos and formatting issues.
>>>>
>>>
>>> What is the resend about ?
>>
>> And to the original v10 there is a reply by Krzysztof;
>> see https://lore.kernel.org/linux-pwm/3d9e50db-19f0-43b3-8042-2f80a1e7b79e@linaro.org/ .
>>
>> I'll mark the original and this resend as "changes-requested" in our
>> patchwork. Probably the most cooperative way to object is to send a v11
>> and point out the changes compared to v10.

> The resend might be fixing issues from v10, but who knows which and how
> many. In any case it should be v11, not a resend.

I apologize for responding to this question inappropriately. I only replied to Guenter and removed
the others.
The reason for the resend is simply to remove the 'Change-Id' in the commit log, which triggers an
error when running scripts/checkpatch.pl. 
It's a minor issue, and I forgot to mention this change in the cover letter.
I sincerely apologize for any confusion.

Best regards,
Billy Tsai

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

^ permalink raw reply	[flat|nested] 31+ messages in thread
* Re: [PATCH RESEND v10 2/3] dt-bindings: hwmon: Support Aspeed g6 PWM TACH Control
  2023-11-27  5:45           ` Billy Tsai
@ 2024-01-13  1:53             ` Rob Herring
  -1 siblings, 0 replies; 31+ messages in thread
From: Rob Herring @ 2024-01-13  1:53 UTC (permalink / raw)
  To: Billy Tsai
  Cc: jdelvare, linux, krzysztof.kozlowski+dt, joel, andrew, corbet,
	thierry.reding, u.kleine-koenig, p.zabel, naresh.solanki,
	linux-hwmon, devicetree, linux-arm-kernel, linux-aspeed,
	linux-kernel, linux-doc, linux-pwm, BMC-SW, patrick

On Sun, Nov 26, 2023 at 11:45 PM Billy Tsai <billy_tsai@aspeedtech.com> wrote:
>
> > > > > Document the compatible for aspeed,ast2600-pwm-tach device, which can
> > > > > support up to 16 PWM outputs and 16 fan tach input.
> > > > >
> > > > > Signed-off-by: Billy Tsai <billy_tsai@aspeedtech.com>
> > > > > ---
> > > > >  .../bindings/hwmon/aspeed,g6-pwm-tach.yaml    | 69 +++++++++++++++++++
> > > > >  1 file changed, 69 insertions(+)
> > > > >  create mode 100644 Documentation/devicetree/bindings/hwmon/aspeed,g6-pwm-tach.yaml
> > > > >
> > > > > diff --git a/Documentation/devicetree/bindings/hwmon/aspeed,g6-pwm-tach.yaml b/Documentation/devicetree/bindings/hwmon/aspeed,g6-pwm-tach.yaml
> > > > > new file mode 100644
> > > > > index 000000000000..c615fb10705c
> > > > > --- /dev/null
> > > > > +++ b/Documentation/devicetree/bindings/hwmon/aspeed,g6-pwm-tach.yaml
> > > > > @@ -0,0 +1,69 @@
> > > > > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > > > > +# Copyright (C) 2023 Aspeed, Inc.
> > > > > +%YAML 1.2
> > > > > +---
> > > > > +$id: http://devicetree.org/schemas/hwmon/aspeed,g6-pwm-tach.yaml#
> > > > > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > > > > +
> > > > > +title: ASPEED G6 PWM and Fan Tach controller
> > > > > +
> > > > > +maintainers:
> > > > > +  - Billy Tsai <billy_tsai@aspeedtech.com>
> > > > > +
> > > > > +description: |
> > > > > +  The ASPEED PWM controller can support up to 16 PWM outputs.
> > > > > +  The ASPEED Fan Tacho controller can support up to 16 fan tach input.
> > > > > +  They are independent hardware blocks, which are different from the
> > > > > +  previous version of the ASPEED chip.
> > > > > +
> > > > > +properties:
> > > > > +  compatible:
> > > > > +    enum:
> > > > > +      - aspeed,ast2600-pwm-tach
> > > > > +
> > > > > +  reg:
> > > > > +    maxItems: 1
> > > > > +
> > > > > +  clocks:
> > > > > +    maxItems: 1
> > > > > +
> > > > > +  resets:
> > > > > +    maxItems: 1
> > > > > +
> > > > > +  "#pwm-cells":
> > > > > +    const: 3
> > > > > +
> > > > > +patternProperties:
> > > > > +  "^fan-[0-9]+$":
> > > > > +    $ref: fan-common.yaml#
> > > > > +    unevaluatedProperties: false
> > > > > +    required:
> > > > > +      - tach-ch
> > > > > +
> > > > > +required:
> > > > > +  - reg
> > > > > +  - clocks
> > > > > +  - resets
> > > > > +  - "#pwm-cells"
> > > > > +  - compatible
> > > > > +
> > > > > +additionalProperties: false
> > > > > +
> > > > > +examples:
> > > > > +  - |
> > > > > +    #include <dt-bindings/clock/aspeed-clock.h>
> > > > > +    pwm_tach: pwm-tach-controller@1e610000 {
> > > > > +      compatible = "aspeed,ast2600-pwm-tach";
> > > > > +      reg = <0x1e610000 0x100>;
> > > > > +      clocks = <&syscon ASPEED_CLK_AHB>;
> > > > > +      resets = <&syscon ASPEED_RESET_PWM>;
> > > > > +      #pwm-cells = <3>;
> > > > > +
> > > > > +      fan-0 {
> > >
> > > > I assume there's a PWM connection here? How do you know which PWM? You
> > > > said the tach channel is independent, so it is not that.
> > >
> > > > It should not be 0 from 'fan-0' because that's just a meaningless index.
> > >
> > > > You either need 'pwms' here or you can use 'reg' and the reg value is
> > > > the PWM channel.
> > >
> > > Hi Rob, this binding is used to export the PWM provider and the Fan monitor (i.e., Tach).
> > > If the user wants to add the PWM connection for the fan, it can be done as follows:
> > >
> > > fan0: pwm-fan0 {
> > >         compatible = "pwm-fan";
> > >         pwms = <&pwm_tach 0 40000 0>;
> > >         cooling-min-state = <0>;
> > >         cooling-max-state = <3>;
> > >         #cooling-cells = <2>;
> > >         cooling-levels = <0 15 128 255>;
> > > };
> > >
> > > This will reuse the existing PWM fan driver (e.g., pwm-fan.c).
>
> > I'm confused now. So what are the child nodes you have? You are
> > defining the fan in 2 places? The "pwm-fan" driver supports a tach via
> > an interrupt, so how would this work in your case?
>
> Hi Rob,
>
> The tach interrupt for the pwm-fan is option. In our case, the dts just reuse the pwm control function
> of the pwm-fan, and the part of the tach monitor will be created by our fan child nodes.
> So the dts will like followings:
>
> // Use to declare the tach monitor for fan.
> &pwm_tach {
>         fan-0 {
>                 tach-ch = /bits/ 8 <0x0>;
>         };
>         fan-1 {
>                 tach-ch = /bits/ 8 <0x1>;
>         };
>         ...
> }
>
> // Reuse the pwm-fan.c to control the behavior of the PWM for fan.
> fan0: pwm-fan0 {
>         compatible = "pwm-fan";
>         pwms = <&pwm_tach 0 40000 0>;   /* Target freq:25 kHz */
>         cooling-min-state = <0>;
>         cooling-max-state = <3>;
>         #cooling-cells = <2>;
>         cooling-levels = <0 15 128 255>;
> };

No, you can't have a fan described by 2 different nodes. Can't you
just merge everything from the pwm-fan0 node into the fan-0 node?

Rob

^ permalink raw reply	[flat|nested] 31+ messages in thread
* Re: [PATCH RESEND v10 2/3] dt-bindings: hwmon: Support Aspeed g6 PWM TACH Control
@ 2024-01-13  1:53             ` Rob Herring
  0 siblings, 0 replies; 31+ messages in thread
From: Rob Herring @ 2024-01-13  1:53 UTC (permalink / raw)
  To: Billy Tsai
  Cc: jdelvare, linux, krzysztof.kozlowski+dt, joel, andrew, corbet,
	thierry.reding, u.kleine-koenig, p.zabel, naresh.solanki,
	linux-hwmon, devicetree, linux-arm-kernel, linux-aspeed,
	linux-kernel, linux-doc, linux-pwm, BMC-SW, patrick

On Sun, Nov 26, 2023 at 11:45 PM Billy Tsai <billy_tsai@aspeedtech.com> wrote:
>
> > > > > Document the compatible for aspeed,ast2600-pwm-tach device, which can
> > > > > support up to 16 PWM outputs and 16 fan tach input.
> > > > >
> > > > > Signed-off-by: Billy Tsai <billy_tsai@aspeedtech.com>
> > > > > ---
> > > > >  .../bindings/hwmon/aspeed,g6-pwm-tach.yaml    | 69 +++++++++++++++++++
> > > > >  1 file changed, 69 insertions(+)
> > > > >  create mode 100644 Documentation/devicetree/bindings/hwmon/aspeed,g6-pwm-tach.yaml
> > > > >
> > > > > diff --git a/Documentation/devicetree/bindings/hwmon/aspeed,g6-pwm-tach.yaml b/Documentation/devicetree/bindings/hwmon/aspeed,g6-pwm-tach.yaml
> > > > > new file mode 100644
> > > > > index 000000000000..c615fb10705c
> > > > > --- /dev/null
> > > > > +++ b/Documentation/devicetree/bindings/hwmon/aspeed,g6-pwm-tach.yaml
> > > > > @@ -0,0 +1,69 @@
> > > > > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > > > > +# Copyright (C) 2023 Aspeed, Inc.
> > > > > +%YAML 1.2
> > > > > +---
> > > > > +$id: http://devicetree.org/schemas/hwmon/aspeed,g6-pwm-tach.yaml#
> > > > > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > > > > +
> > > > > +title: ASPEED G6 PWM and Fan Tach controller
> > > > > +
> > > > > +maintainers:
> > > > > +  - Billy Tsai <billy_tsai@aspeedtech.com>
> > > > > +
> > > > > +description: |
> > > > > +  The ASPEED PWM controller can support up to 16 PWM outputs.
> > > > > +  The ASPEED Fan Tacho controller can support up to 16 fan tach input.
> > > > > +  They are independent hardware blocks, which are different from the
> > > > > +  previous version of the ASPEED chip.
> > > > > +
> > > > > +properties:
> > > > > +  compatible:
> > > > > +    enum:
> > > > > +      - aspeed,ast2600-pwm-tach
> > > > > +
> > > > > +  reg:
> > > > > +    maxItems: 1
> > > > > +
> > > > > +  clocks:
> > > > > +    maxItems: 1
> > > > > +
> > > > > +  resets:
> > > > > +    maxItems: 1
> > > > > +
> > > > > +  "#pwm-cells":
> > > > > +    const: 3
> > > > > +
> > > > > +patternProperties:
> > > > > +  "^fan-[0-9]+$":
> > > > > +    $ref: fan-common.yaml#
> > > > > +    unevaluatedProperties: false
> > > > > +    required:
> > > > > +      - tach-ch
> > > > > +
> > > > > +required:
> > > > > +  - reg
> > > > > +  - clocks
> > > > > +  - resets
> > > > > +  - "#pwm-cells"
> > > > > +  - compatible
> > > > > +
> > > > > +additionalProperties: false
> > > > > +
> > > > > +examples:
> > > > > +  - |
> > > > > +    #include <dt-bindings/clock/aspeed-clock.h>
> > > > > +    pwm_tach: pwm-tach-controller@1e610000 {
> > > > > +      compatible = "aspeed,ast2600-pwm-tach";
> > > > > +      reg = <0x1e610000 0x100>;
> > > > > +      clocks = <&syscon ASPEED_CLK_AHB>;
> > > > > +      resets = <&syscon ASPEED_RESET_PWM>;
> > > > > +      #pwm-cells = <3>;
> > > > > +
> > > > > +      fan-0 {
> > >
> > > > I assume there's a PWM connection here? How do you know which PWM? You
> > > > said the tach channel is independent, so it is not that.
> > >
> > > > It should not be 0 from 'fan-0' because that's just a meaningless index.
> > >
> > > > You either need 'pwms' here or you can use 'reg' and the reg value is
> > > > the PWM channel.
> > >
> > > Hi Rob, this binding is used to export the PWM provider and the Fan monitor (i.e., Tach).
> > > If the user wants to add the PWM connection for the fan, it can be done as follows:
> > >
> > > fan0: pwm-fan0 {
> > >         compatible = "pwm-fan";
> > >         pwms = <&pwm_tach 0 40000 0>;
> > >         cooling-min-state = <0>;
> > >         cooling-max-state = <3>;
> > >         #cooling-cells = <2>;
> > >         cooling-levels = <0 15 128 255>;
> > > };
> > >
> > > This will reuse the existing PWM fan driver (e.g., pwm-fan.c).
>
> > I'm confused now. So what are the child nodes you have? You are
> > defining the fan in 2 places? The "pwm-fan" driver supports a tach via
> > an interrupt, so how would this work in your case?
>
> Hi Rob,
>
> The tach interrupt for the pwm-fan is option. In our case, the dts just reuse the pwm control function
> of the pwm-fan, and the part of the tach monitor will be created by our fan child nodes.
> So the dts will like followings:
>
> // Use to declare the tach monitor for fan.
> &pwm_tach {
>         fan-0 {
>                 tach-ch = /bits/ 8 <0x0>;
>         };
>         fan-1 {
>                 tach-ch = /bits/ 8 <0x1>;
>         };
>         ...
> }
>
> // Reuse the pwm-fan.c to control the behavior of the PWM for fan.
> fan0: pwm-fan0 {
>         compatible = "pwm-fan";
>         pwms = <&pwm_tach 0 40000 0>;   /* Target freq:25 kHz */
>         cooling-min-state = <0>;
>         cooling-max-state = <3>;
>         #cooling-cells = <2>;
>         cooling-levels = <0 15 128 255>;
> };

No, you can't have a fan described by 2 different nodes. Can't you
just merge everything from the pwm-fan0 node into the fan-0 node?

Rob

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^ permalink raw reply	[flat|nested] 31+ messages in thread
end of thread, other threads:[~2024-01-13  1:54 UTC | newest]

Thread overview: 31+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2023-11-07 10:50 [PATCH RESEND v10 0/3] Support pwm/tach driver for aspeed ast26xx Billy Tsai
2023-11-07 10:50 ` Billy Tsai
2023-11-07 10:50 ` [PATCH RESEND v10 1/3] dt-bindings: hwmon: fan: Add fan binding to schema Billy Tsai
2023-11-07 10:50   ` Billy Tsai
2023-11-08 18:16   ` Rob Herring
2023-11-08 18:16     ` Rob Herring
2023-11-08 18:38     ` Guenter Roeck
2023-11-08 18:38       ` Guenter Roeck
2023-11-07 10:50 ` [PATCH RESEND v10 2/3] dt-bindings: hwmon: Support Aspeed g6 PWM TACH Control Billy Tsai
2023-11-07 10:50   ` Billy Tsai
2023-11-08 18:21   ` Rob Herring
2023-11-08 18:21     ` Rob Herring
2023-11-14  3:11     ` Billy Tsai
2023-11-14  3:11       ` Billy Tsai
2023-11-22 20:47       ` Rob Herring
2023-11-22 20:47         ` Rob Herring
2023-11-27  5:45         ` Billy Tsai
2023-11-27  5:45           ` Billy Tsai
2024-01-13  1:53           ` Rob Herring
2024-01-13  1:53             ` Rob Herring
2023-11-07 10:50 ` [PATCH RESEND v10 3/3] hwmon: (aspeed-g6-pwm-tacho): Support for ASPEED g6 PWM/Fan tach Billy Tsai
2023-11-07 10:50   ` Billy Tsai
2023-11-07 19:02 ` [PATCH RESEND v10 0/3] Support pwm/tach driver for aspeed ast26xx Guenter Roeck
2023-11-07 19:02   ` Guenter Roeck
     [not found]   ` <SG2PR06MB33658A0B3EA8FD0870D8AC388BA8A@SG2PR06MB3365.apcprd06.prod.outlook.com>
2023-11-08  6:03     ` Guenter Roeck
2023-12-06 17:48   ` Uwe Kleine-König
2023-12-06 17:48     ` Uwe Kleine-König
2023-12-06 17:56     ` Krzysztof Kozlowski
2023-12-06 17:56       ` Krzysztof Kozlowski
2023-12-13  3:23       ` Billy Tsai
2023-12-13  3:23         ` Billy Tsai

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