[PATCH v2 0/2] usb: gadget: Add clock support

[PATCH v2 0/2] usb: gadget: Add clock support

[Shubhrajyoti Datta]

Add clock support to udc xilinx.

v2:
Add the clock binding

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

 .../devicetree/bindings/usb/xlnx,usb2.yaml    |  8 +++++++
 drivers/usb/gadget/udc/udc-xilinx.c           | 24 +++++++++++++++++++
 2 files changed, 32 insertions(+)

-- 
2.17.1

[PATCH v2 1/2] 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>
---
 drivers/usb/gadget/udc/udc-xilinx.c | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/drivers/usb/gadget/udc/udc-xilinx.c b/drivers/usb/gadget/udc/udc-xilinx.c
index fb4ffedd6f0d..30070a488c87 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 +2095,26 @@ 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
+		 */
+		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 +2170,7 @@ 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;
 }
-- 
2.17.1

Re: [PATCH v2 1/2] usb: gadget: udc-xilinx: Add clock support

[Felipe Balbi]

Hi,

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>
> ---
>  drivers/usb/gadget/udc/udc-xilinx.c | 24 ++++++++++++++++++++++++
>  1 file changed, 24 insertions(+)
>
> diff --git a/drivers/usb/gadget/udc/udc-xilinx.c b/drivers/usb/gadget/udc/udc-xilinx.c
> index fb4ffedd6f0d..30070a488c87 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 +2095,26 @@ 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)) {

might be a way idea to add a dev_warn() here in case you get
ENOENT. This should let people that DTS has to be updated accordingly.

-- 
balbi

[PATCH v2 2/2] 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
-- 
2.17.1