[PATCH v3 0/2] usb: gadget: Add clock support

[PATCH v3 0/2] usb: gadget: Add clock support

[Shubhrajyoti Datta]

Add clock support to udc xilinx.

v2:
Add the clock binding
v3:
Add a warn print

Shubhrajyoti Datta (2):
  dt-binding: usb: xilinx: Add clocking node
  usb: gadget: udc-xilinx: Add clock support

 .../devicetree/bindings/usb/xlnx,usb2.yaml    |  8 ++++++
 drivers/usb/gadget/udc/udc-xilinx.c           | 25 +++++++++++++++++++
 2 files changed, 33 insertions(+)

-- 
2.25.1

[PATCH v3 1/2] dt-binding: usb: xilinx: Add clocking node

[Shubhrajyoti Datta]

Add a clocking node for xilinx udc.

Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
---
 Documentation/devicetree/bindings/usb/xlnx,usb2.yaml | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/Documentation/devicetree/bindings/usb/xlnx,usb2.yaml b/Documentation/devicetree/bindings/usb/xlnx,usb2.yaml
index b8acc415eaf1..39213806ac79 100644
--- a/Documentation/devicetree/bindings/usb/xlnx,usb2.yaml
+++ b/Documentation/devicetree/bindings/usb/xlnx,usb2.yaml
@@ -24,6 +24,14 @@ properties:
       If present, hardware has dma capability.
     type: boolean
 
+  clocks:
+    minItems: 1
+
+  clock-name:
+    const: "s_axi_aclk"
+    description: |
+      Input clock name.
+
 required:
   - compatible
   - reg
-- 
2.25.1

[PATCH v3 2/2] usb: gadget: udc-xilinx: Add clock support

[Shubhrajyoti Datta]

Currently the driver depends on the  bootloader to enable the clocks.
Add support for clocking. The patch enables the clock at  probe and
disables them at remove.

Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
---
v3:
Add dev_warn

 drivers/usb/gadget/udc/udc-xilinx.c | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/drivers/usb/gadget/udc/udc-xilinx.c b/drivers/usb/gadget/udc/udc-xilinx.c
index fb4ffedd6f0d..f5ca670776a3 100644
--- a/drivers/usb/gadget/udc/udc-xilinx.c
+++ b/drivers/usb/gadget/udc/udc-xilinx.c
@@ -11,6 +11,7 @@
  * USB peripheral controller (at91_udc.c).
  */
 
+#include <linux/clk.h>
 #include <linux/delay.h>
 #include <linux/device.h>
 #include <linux/dma-mapping.h>
@@ -171,6 +172,7 @@ struct xusb_ep {
  * @addr: the usb device base address
  * @lock: instance of spinlock
  * @dma_enabled: flag indicating whether the dma is included in the system
+ * @clk: pointer to struct clk
  * @read_fn: function pointer to read device registers
  * @write_fn: function pointer to write to device registers
  */
@@ -188,6 +190,7 @@ struct xusb_udc {
 	void __iomem *addr;
 	spinlock_t lock;
 	bool dma_enabled;
+	struct clk *clk;
 
 	unsigned int (*read_fn)(void __iomem *);
 	void (*write_fn)(void __iomem *, u32, u32);
@@ -2092,6 +2095,27 @@ static int xudc_probe(struct platform_device *pdev)
 	udc->gadget.ep0 = &udc->ep[XUSB_EP_NUMBER_ZERO].ep_usb;
 	udc->gadget.name = driver_name;
 
+	udc->clk = devm_clk_get(&pdev->dev, "s_axi_aclk");
+	if (IS_ERR(udc->clk)) {
+		if (PTR_ERR(udc->clk) != -ENOENT) {
+			ret = PTR_ERR(udc->clk);
+			goto fail;
+		}
+
+		/*
+		 * Clock framework support is optional, continue on,
+		 * anyways if we don't find a matching clock
+		 */
+		dev_warn(&pdev->dev, "s_axi_aclk clock property is not found\n");
+		udc->clk = NULL;
+	}
+
+	ret = clk_prepare_enable(udc->clk);
+	if (ret) {
+		dev_err(&pdev->dev, "Unable to enable clock.\n");
+		return ret;
+	}
+
 	spin_lock_init(&udc->lock);
 
 	/* Check for IP endianness */
@@ -2147,6 +2171,7 @@ static int xudc_remove(struct platform_device *pdev)
 	struct xusb_udc *udc = platform_get_drvdata(pdev);
 
 	usb_del_gadget_udc(&udc->gadget);
+	clk_disable_unprepare(udc->clk);
 
 	return 0;
 }
-- 
2.25.1

Re: [PATCH v3 2/2] usb: gadget: udc-xilinx: Add clock support

[Felipe Balbi]

Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com> writes:

> Currently the driver depends on the  bootloader to enable the clocks.
> Add support for clocking. The patch enables the clock at  probe and
> disables them at remove.
>
> Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>

Acked-by: Felipe Balbi <balbi@kernel.org>

-- 
balbi

Re: [PATCH v3 1/2] dt-binding: usb: xilinx: Add clocking node

[Rob Herring]

On Wed, Sep 22, 2021 at 04:41:25PM +0530, Shubhrajyoti Datta wrote:
> Add a clocking node for xilinx udc.
> 
> Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
> ---
>  Documentation/devicetree/bindings/usb/xlnx,usb2.yaml | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/usb/xlnx,usb2.yaml b/Documentation/devicetree/bindings/usb/xlnx,usb2.yaml
> index b8acc415eaf1..39213806ac79 100644
> --- a/Documentation/devicetree/bindings/usb/xlnx,usb2.yaml
> +++ b/Documentation/devicetree/bindings/usb/xlnx,usb2.yaml
> @@ -24,6 +24,14 @@ properties:
>        If present, hardware has dma capability.
>      type: boolean
>  
> +  clocks:
> +    minItems: 1
> +
> +  clock-name:

I think you meant 'clock-names'.

> +    const: "s_axi_aclk"

Don't need quotes.

> +    description: |
> +      Input clock name.

That's every 'clock-names'. You can drop description.

> +
>  required:
>    - compatible
>    - reg
> -- 
> 2.25.1
> 
>