| Message ID | 20210818094726.3295093-1-shubhrajyoti.datta@xilinx.com |
|---|---|
| State | New |
| Headers | show |
| Series | usb: gadget: udc-xilinx: Add clock support | expand |
> -----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
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
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; }
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(+)