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usb: gadget: Add clock support

PATCH In review Shubhrajyoti Datta 4 participants 7 messages Sep 28, 2021 – Oct 8, 2021

Subsystems (3)
Device tree bindings USB Arm/Zynq architecture
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Shubhrajyoti Datta

author
#0 lore raw

v4 cover usb: gadget: Add clock support

Add clock support to udc xilinx.

v2:
Add the clock binding
v3:
Add a warn print
v4:
Update the clock binding

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

 .../devicetree/bindings/usb/xlnx,usb2.yaml    |  6 +++++
 drivers/usb/gadget/udc/udc-xilinx.c           | 25 +++++++++++++++++++
 2 files changed, 31 insertions(+)
Signature · 1 line
2.25.1
author
#1 lore raw

PATCH v4 1/2 dt-binding: usb: xilinx: Add clocking node

Add a clocking node for xilinx udc.

Signed-off-by Shubhrajyoti Datta <[email protected]>

---
v3:
update clock description and names

 Documentation/devicetree/bindings/usb/xlnx,usb2.yaml | 6 ++++++
 1 file changed, 6 insertions(+)
Documentation/devicetree/bindings/usb/xlnx,usb2.yaml +6 -0
index b8acc415eaf1..04c123c7252a 100644
@@ -24,6 +24,12 @@ properties:
       If present, hardware has dma capability.
     type: boolean
 
+  clocks:
+    minItems: 1
+
+  clock-names:
+    const: s_axi_aclk
+
 required:
   - compatible
   - reg
Signature · 1 line
2.25.1
#3 lore raw

Re: [PATCH v4 1/2] dt-binding: usb: xilinx: Add clocking node

In reply to Shubhrajyoti Datta
Quoted 8 lines · Shubhrajyoti Datta

Add a clocking node for xilinx udc.

Signed-off-by Shubhrajyoti Datta <[email protected]>

---
v3:
update clock description and names

 Documentation/devicetree/bindings/usb/xlnx,usb2.yaml | 6 ++++++

This file is not in my tree, where does it come from?

thanks,

greg k-h

#4 lore raw

Re: [PATCH v4 1/2] dt-binding: usb: xilinx: Add clocking node

Quoted 11 lines · Greg KH
Quoted 8 lines · Shubhrajyoti Datta

Add a clocking node for xilinx udc.

Signed-off-by Shubhrajyoti Datta <[email protected]>

---
v3:
update clock description and names

 Documentation/devicetree/bindings/usb/xlnx,usb2.yaml | 6 ++++++

This file is not in my tree, where does it come from?

In linux-next I see that Rob has applied it to his tree as commit ecc4103f32e9 ("dt-binding: usb: xilinx: Convert binding to YAML")

Thanks,
Michal

maintainer
#5 lore raw

Re: [PATCH v4 1/2] dt-binding: usb: xilinx: Add clocking node

In reply to Shubhrajyoti Datta
Quoted 10 lines · Shubhrajyoti Datta

Add a clocking node for xilinx udc.

Signed-off-by Shubhrajyoti Datta <[email protected]>

---
v3:
update clock description and names

 Documentation/devicetree/bindings/usb/xlnx,usb2.yaml | 6 ++++++
 1 file changed, 6 insertions(+)

Since I picked up the conversion, applied. Thanks!

author
#6 lore raw

PATCH v4 2/2 usb: gadget: udc-xilinx: Add clock support

In reply to 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 <[email protected]>
Acked-by Felipe Balbi <[email protected]>

---
v3:
Add dev_warn

 drivers/usb/gadget/udc/udc-xilinx.c | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)
drivers/usb/gadget/udc/udc-xilinx.c +25 -0
index fb4ffedd6f0d..f5ca670776a3 100644
@@ -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;
 }
Signature · 1 line
2.25.1