Linux-PWM Archive mirror
 help / color / mirror / Atom feed
From: Jerome Brunet <jbrunet@baylibre.com>
To: Thierry Reding <thierry.reding@gmail.com>,
	Neil Armstrong <neil.armstrong@linaro.org>,
	Rob Herring <robh+dt@kernel.org>,
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
	Conor Dooley <conor+dt@kernel.org>
Cc: "Jerome Brunet" <jbrunet@baylibre.com>,
	"Kevin Hilman" <khilman@baylibre.com>,
	devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-amlogic@lists.infradead.org, linux-pwm@vger.kernel.org,
	"JunYi Zhao" <junyi.zhao@amlogic.com>,
	"Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>,
	"Rob Herring" <robh@kernel.org>
Subject: [PATCH v3 1/4] dt-bindings: pwm: amlogic: fix s4 bindings
Date: Wed, 29 Nov 2023 14:39:57 +0100	[thread overview]
Message-ID: <20231129134004.3642121-2-jbrunet@baylibre.com> (raw)
In-Reply-To: <20231129134004.3642121-1-jbrunet@baylibre.com>

s4 has been added to the compatible list while converting the Amlogic PWM
binding documentation from txt to yaml.

However, on the s4, the clock bindings have different meaning compared to
the previous SoCs.

On the previous SoCs the clock bindings used to describe which input the
PWM channel multiplexer should pick among its possible parents.

This is very much tied to the driver implementation, instead of describing
the HW for what it is. When support for the Amlogic PWM was first added,
how to deal with clocks through DT was not as clear as it nowadays.
The Linux driver now ignores this DT setting, but still relies on the
hard-coded list of clock sources.

On the s4, the input multiplexer is gone. The clock bindings actually
describe the clock as it exists, not a setting. The property has a
different meaning, even if it is still 2 clocks and it would pass the check
when support is actually added.

Also the s4 cannot work if the clocks are not provided, so the property no
longer optional.

Finally, for once it makes sense to see the input as being numbered
somehow. No need to bother with clock-names on the s4 type of PWM.

Fixes: 43a1c4ff3977 ("dt-bindings: pwm: Convert Amlogic Meson PWM binding")
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
---
 .../devicetree/bindings/pwm/pwm-amlogic.yaml  | 69 ++++++++++++++++---
 1 file changed, 60 insertions(+), 9 deletions(-)

diff --git a/Documentation/devicetree/bindings/pwm/pwm-amlogic.yaml b/Documentation/devicetree/bindings/pwm/pwm-amlogic.yaml
index 527864a4d855..387976ed36d5 100644
--- a/Documentation/devicetree/bindings/pwm/pwm-amlogic.yaml
+++ b/Documentation/devicetree/bindings/pwm/pwm-amlogic.yaml
@@ -9,9 +9,6 @@ title: Amlogic PWM
 maintainers:
   - Heiner Kallweit <hkallweit1@gmail.com>
 
-allOf:
-  - $ref: pwm.yaml#
-
 properties:
   compatible:
     oneOf:
@@ -43,12 +40,8 @@ properties:
     maxItems: 2
 
   clock-names:
-    oneOf:
-      - items:
-          - enum: [clkin0, clkin1]
-      - items:
-          - const: clkin0
-          - const: clkin1
+    minItems: 1
+    maxItems: 2
 
   "#pwm-cells":
     const: 3
@@ -57,6 +50,57 @@ required:
   - compatible
   - reg
 
+allOf:
+  - $ref: pwm.yaml#
+
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - amlogic,meson8-pwm
+              - amlogic,meson8b-pwm
+              - amlogic,meson-gxbb-pwm
+              - amlogic,meson-gxbb-ao-pwm
+              - amlogic,meson-axg-ee-pwm
+              - amlogic,meson-axg-ao-pwm
+              - amlogic,meson-g12a-ee-pwm
+              - amlogic,meson-g12a-ao-pwm-ab
+              - amlogic,meson-g12a-ao-pwm-cd
+              - amlogic,meson-gx-pwm
+              - amlogic,meson-gx-ao-pwm
+    then:
+      # Historic bindings tied to the driver implementation
+      # The clocks provided here are meant to be matched with the input
+      # known (hard-coded) in the driver and used to select pwm clock
+      # source. Currently, the linux driver ignores this.
+      properties:
+        clock-names:
+          oneOf:
+            - items:
+                - enum: [clkin0, clkin1]
+            - items:
+                - const: clkin0
+                - const: clkin1
+
+  # Newer IP block take a single input per channel, instead of 4 inputs
+  # for both channels
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - amlogic,meson-s4-pwm
+    then:
+      properties:
+        clocks:
+          items:
+            - description: input clock of PWM channel A
+            - description: input clock of PWM channel B
+        clock-names: false
+      required:
+        - clocks
+
 additionalProperties: false
 
 examples:
@@ -68,3 +112,10 @@ examples:
       clock-names = "clkin0", "clkin1";
       #pwm-cells = <3>;
     };
+  - |
+    pwm@1000 {
+      compatible = "amlogic,meson-s4-pwm";
+      reg = <0x1000 0x10>;
+      clocks = <&pwm_src_a>, <&pwm_src_b>;
+      #pwm-cells = <3>;
+    };
-- 
2.42.0


  reply	other threads:[~2023-11-29 13:40 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-11-29 13:39 [PATCH v3 0/4] pwm: meson: dt-bindings fixup Jerome Brunet
2023-11-29 13:39 ` Jerome Brunet [this message]
2023-11-29 13:39 ` [PATCH v3 2/4] dt-bindings: pwm: amlogic: add new compatible for meson8 pwm type Jerome Brunet
2023-11-29 16:20   ` Neil Armstrong
2023-11-29 16:26     ` Jerome Brunet
2023-11-29 16:41       ` neil.armstrong
2023-11-30  8:36         ` Krzysztof Kozlowski
2023-11-30  9:13           ` neil.armstrong
2023-11-29 13:39 ` [PATCH v3 3/4] pwm: meson: prepare addition of new compatible types Jerome Brunet
2023-11-29 16:25   ` Neil Armstrong
2023-11-29 13:40 ` [PATCH v3 4/4] pwm: meson: add generic compatible for meson8 to sm1 Jerome Brunet
2023-11-29 16:30   ` Neil Armstrong

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20231129134004.3642121-2-jbrunet@baylibre.com \
    --to=jbrunet@baylibre.com \
    --cc=conor+dt@kernel.org \
    --cc=devicetree@vger.kernel.org \
    --cc=junyi.zhao@amlogic.com \
    --cc=khilman@baylibre.com \
    --cc=krzysztof.kozlowski+dt@linaro.org \
    --cc=linux-amlogic@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-pwm@vger.kernel.org \
    --cc=neil.armstrong@linaro.org \
    --cc=robh+dt@kernel.org \
    --cc=robh@kernel.org \
    --cc=thierry.reding@gmail.com \
    --cc=u.kleine-koenig@pengutronix.de \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).