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

[PATCH] 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;
 }
-- 
2.25.1

RE: [PATCH] usb: gadget: udc-xilinx: Add clock support

[Shubhrajyoti Datta]

> -----Original Message-----
> From: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
> Sent: Wednesday, August 18, 2021 3:17 PM
> To: linux-usb@vger.kernel.org
> Cc: gregkh@linuxfoundation.org; Michal Simek <michals@xilinx.com>; git
> <git@xilinx.com>; Shubhrajyoti Datta <shubhraj@xilinx.com>
> Subject: [PATCH] usb: gadget: udc-xilinx: Add clock support
> 
> 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>
> ---

Please ignore will resend

Re: [PATCH] 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)) {
> +		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;

should it be, though? Might be a good idea to add fixed-clock instances
to the boards still depending on clock framework. Maybe that can be done
over time, but worth considering anyhow.

-- 
balbi

RE: [PATCH] usb: gadget: udc-xilinx: Add clock support

[Shubhrajyoti Datta]

> -----Original Message-----
> From: Felipe Balbi <balbi@kernel.org>
> Sent: Wednesday, August 18, 2021 3:24 PM
> To: Shubhrajyoti Datta <shubhraj@xilinx.com>
> Cc: linux-usb@vger.kernel.org; gregkh@linuxfoundation.org; Michal Simek
> <michals@xilinx.com>; git <git@xilinx.com>
> Subject: Re: [PATCH] usb: gadget: udc-xilinx: Add clock support
> 
> 
> 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)) {
> > +		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;
> 
> should it be, though? Might be a good idea to add fixed-clock instances to the
> boards still depending on clock framework. Maybe that can be done over time,
> but worth considering anyhow.

But for backward compatibility , I think it will be good to have the support instead of forcing the fixed-clock node.
> 
> --
> balbi

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

[Felipe Balbi]

Hi,

Shubhrajyoti Datta <shubhraj@xilinx.com> writes:
>> -----Original Message-----
>> From: Felipe Balbi <balbi@kernel.org>
>> Sent: Wednesday, August 18, 2021 3:24 PM
>> To: Shubhrajyoti Datta <shubhraj@xilinx.com>
>> Cc: linux-usb@vger.kernel.org; gregkh@linuxfoundation.org; Michal Simek
>> <michals@xilinx.com>; git <git@xilinx.com>
>> Subject: Re: [PATCH] usb: gadget: udc-xilinx: Add clock support
>> 
>> 
>> 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)) {
>> > +		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;
>> 
>> should it be, though? Might be a good idea to add fixed-clock instances to the
>> boards still depending on clock framework. Maybe that can be done over time,
>> but worth considering anyhow.
>
> But for backward compatibility , I think it will be good to have the
> support instead of forcing the fixed-clock node.

you gotta explain that a little better. Care to do so?

-- 
balbi