[PATCH 0/2] usb: dwc2: Use clk bulk API for supporting multiple clocks

[PATCH 0/2] usb: dwc2: Use clk bulk API for supporting multiple clocks

[Sascha Hauer]

Currently the dwc2 driver only supports a single clock. I have a board
here which has a dwc2 controller with a somewhat special clock routing
to the phy. Both the dwc2 controller and the ULPI phy get their phy
clock from a SI5351 clock generator. This clock generator has multiple
clock outputs which each is modelled as a separate clk in Linux.
Unfortunately the clock to the phy and the clock to the dwc2 core are on
two different output pins of the SI5351, so we have two clocks which
must be enabled.  The phy is driven by the usb-nop-xceiver driver which
supports a single clock. My first approach was to add support for a
second clock to that driver, but technically the other clock is
connected to the dwc2 core, so instead I added support for a second
clock to the dwc2 driver.  This can easily be archieved with the clk
bulk API as done in this series.

Sascha

Sascha Hauer (2):
  dt-bindings: usb: dwc2: Add support for additional clock
  usb: dwc2: use clk bulk API for supporting additional clocks

 .../devicetree/bindings/usb/dwc2.yaml          |  3 ++-
 drivers/usb/dwc2/core.h                        |  2 ++
 drivers/usb/dwc2/platform.c                    | 18 ++++++++----------
 3 files changed, 12 insertions(+), 11 deletions(-)

-- 
2.20.1

[PATCH 1/2] dt-bindings: usb: dwc2: Add support for additional clock

[Sascha Hauer]

This adds support for an additional clock for the dwc2 core in case
there is another clock to the phy which must be enabled.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
 Documentation/devicetree/bindings/usb/dwc2.yaml | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/usb/dwc2.yaml b/Documentation/devicetree/bindings/usb/dwc2.yaml
index e5ee51b7b470..20d0847c7b01 100644
--- a/Documentation/devicetree/bindings/usb/dwc2.yaml
+++ b/Documentation/devicetree/bindings/usb/dwc2.yaml
@@ -57,11 +57,12 @@ properties:
     maxItems: 1
 
   clocks:
-    maxItems: 1
+    maxItems: 2
 
   clock-names:
     items:
       - const: otg
+      - const: phy
 
   resets:
     items:
-- 
2.20.1

[PATCH 2/2] usb: dwc2: use clk bulk API for supporting additional clocks

[Sascha Hauer]

This switches to the clk bulk API for the dwc2 driver. With this
additional clocks can be supported.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
 drivers/usb/dwc2/core.h     |  2 ++
 drivers/usb/dwc2/platform.c | 18 ++++++++----------
 2 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/drivers/usb/dwc2/core.h b/drivers/usb/dwc2/core.h
index 7161344c6522..4c9e2c75f3dd 100644
--- a/drivers/usb/dwc2/core.h
+++ b/drivers/usb/dwc2/core.h
@@ -1075,6 +1075,8 @@ struct dwc2_hsotg {
 	spinlock_t lock;
 	void *priv;
 	int     irq;
+	struct clk_bulk_data *clocks;
+	int num_clocks;
 	struct clk *clk;
 	struct reset_control *reset;
 	struct reset_control *reset_ecc;
diff --git a/drivers/usb/dwc2/platform.c b/drivers/usb/dwc2/platform.c
index 5f18acac7406..d4a1a26103da 100644
--- a/drivers/usb/dwc2/platform.c
+++ b/drivers/usb/dwc2/platform.c
@@ -143,11 +143,9 @@ static int __dwc2_lowlevel_hw_enable(struct dwc2_hsotg *hsotg)
 	if (ret)
 		return ret;
 
-	if (hsotg->clk) {
-		ret = clk_prepare_enable(hsotg->clk);
-		if (ret)
-			return ret;
-	}
+	ret = clk_bulk_prepare_enable(hsotg->num_clocks, hsotg->clocks);
+	if (ret)
+		return ret;
 
 	if (hsotg->uphy) {
 		ret = usb_phy_init(hsotg->uphy);
@@ -195,8 +193,7 @@ static int __dwc2_lowlevel_hw_disable(struct dwc2_hsotg *hsotg)
 	if (ret)
 		return ret;
 
-	if (hsotg->clk)
-		clk_disable_unprepare(hsotg->clk);
+	clk_bulk_disable_unprepare(hsotg->num_clocks, hsotg->clocks);
 
 	return 0;
 }
@@ -281,11 +278,12 @@ static int dwc2_lowlevel_hw_init(struct dwc2_hsotg *hsotg)
 	hsotg->plat = dev_get_platdata(hsotg->dev);
 
 	/* Clock */
-	hsotg->clk = devm_clk_get_optional(hsotg->dev, "otg");
-	if (IS_ERR(hsotg->clk)) {
+	ret = devm_clk_bulk_get_all(hsotg->dev, &hsotg->clocks);
+	if (ret < 0) {
 		dev_err(hsotg->dev, "cannot get otg clock\n");
-		return PTR_ERR(hsotg->clk);
+		return ret;
 	}
+	hsotg->num_clocks = ret;
 
 	/* Regulators */
 	for (i = 0; i < ARRAY_SIZE(hsotg->supplies); i++)
-- 
2.20.1

Re: [PATCH 1/2] dt-bindings: usb: dwc2: Add support for additional clock

[Rob Herring]

On Mon, 11 Jan 2021 16:13:36 +0100, Sascha Hauer wrote:
> This adds support for an additional clock for the dwc2 core in case
> there is another clock to the phy which must be enabled.
> 
> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
> ---
>  Documentation/devicetree/bindings/usb/dwc2.yaml | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 

My bot found errors running 'make dt_binding_check' on your patch:

yamllint warnings/errors:

dtschema/dtc warnings/errors:
/builds/robherring/linux-dt-review/Documentation/devicetree/bindings/usb/amlogic,meson-g12a-usb-ctrl.example.dt.yaml: usb@ff400000: clocks: [[4294967295]] is too short
	From schema: /builds/robherring/linux-dt-review/Documentation/devicetree/bindings/usb/dwc2.yaml
/builds/robherring/linux-dt-review/Documentation/devicetree/bindings/usb/amlogic,meson-g12a-usb-ctrl.example.dt.yaml: usb@ff400000: clock-names: ['otg'] is too short
	From schema: /builds/robherring/linux-dt-review/Documentation/devicetree/bindings/usb/dwc2.yaml
/builds/robherring/linux-dt-review/Documentation/devicetree/bindings/usb/dwc2.example.dt.yaml: usb@101c0000: clocks: [[4294967295]] is too short
	From schema: /builds/robherring/linux-dt-review/Documentation/devicetree/bindings/usb/dwc2.yaml
/builds/robherring/linux-dt-review/Documentation/devicetree/bindings/usb/dwc2.example.dt.yaml: usb@101c0000: clock-names: ['otg'] is too short
	From schema: /builds/robherring/linux-dt-review/Documentation/devicetree/bindings/usb/dwc2.yaml

See https://patchwork.ozlabs.org/patch/1424674

This check can fail if there are any dependencies. The base for a patch
series is generally the most recent rc1.

If you already ran 'make dt_binding_check' and didn't see the above
error(s), then make sure 'yamllint' is installed and dt-schema is up to
date:

pip3 install dtschema --upgrade

Please check and re-submit.

Re: [PATCH 1/2] dt-bindings: usb: dwc2: Add support for additional clock

[Sascha Hauer]

On Mon, Jan 11, 2021 at 11:41:09AM -0600, Rob Herring wrote:
> On Mon, 11 Jan 2021 16:13:36 +0100, Sascha Hauer wrote:
> > This adds support for an additional clock for the dwc2 core in case
> > there is another clock to the phy which must be enabled.
> > 
> > Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
> > ---
> >  Documentation/devicetree/bindings/usb/dwc2.yaml | 3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)
> > 
> 
> My bot found errors running 'make dt_binding_check' on your patch:
> 
> yamllint warnings/errors:
> 
> dtschema/dtc warnings/errors:
> /builds/robherring/linux-dt-review/Documentation/devicetree/bindings/usb/amlogic,meson-g12a-usb-ctrl.example.dt.yaml: usb@ff400000: clocks: [[4294967295]] is too short
> 	From schema: /builds/robherring/linux-dt-review/Documentation/devicetree/bindings/usb/dwc2.yaml
> /builds/robherring/linux-dt-review/Documentation/devicetree/bindings/usb/amlogic,meson-g12a-usb-ctrl.example.dt.yaml: usb@ff400000: clock-names: ['otg'] is too short
> 	From schema: /builds/robherring/linux-dt-review/Documentation/devicetree/bindings/usb/dwc2.yaml
> /builds/robherring/linux-dt-review/Documentation/devicetree/bindings/usb/dwc2.example.dt.yaml: usb@101c0000: clocks: [[4294967295]] is too short

Ok, this can be fixed by adding a "minItems" property to clocks and
clock-names. Will do next round.

Anything more to say to this series?

Sascha

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