[linux-devel] [PATCH 2/3] usb: dwc3 : Add support for USB snooping

Leo Li leoyang.li at nxp.com
Fri Aug 11 09:18:58 PDT 2017



> -----Original Message-----
> From: linux-devel-bounces at gforge.freescale.net [mailto:linux-devel-
> bounces at gforge.freescale.net] On Behalf Of yinbo.zhu at nxp.com
> Sent: Friday, August 11, 2017 5:00 AM
> To: linux-devel at gforge.freescale.net; Yinbo Zhu <yinbo.zhu at nxp.com>; Rob
> Herring <robh+dt at kernel.org>; Mark Rutland <mark.rutland at arm.com>;
> Russell King <linux at armlinux.org.uk>; Felipe Balbi <balbi at kernel.org>
> Cc: open list <devicetree at vger.kernel.org>; Laurent Pinchart
> <laurent.pinchart+renesas at ideasonboard.com>; Catalin Marinas
> <catalin.marinas at arm.com>; open list <linux-usb at vger.kernel.org>; open list
> <linux-kernel at vger.kernel.org>; Doug Ledford <dledford at redhat.com>;
> Stefano Stabellini <sstabellini at kernel.org>; Greg Kroah-Hartman
> <gregkh at linuxfoundation.org>; Bart Van Assche
> <bart.vanassche at sandisk.com>; moderated list <linux-arm-
> kernel at lists.infradead.org>
> Subject: [linux-devel] [PATCH 2/3] usb: dwc3 : Add support for USB snooping
> 
> From: Rajesh Bhagat <rajesh.bhagat at freescale.com>
> 
> Add support for USB3 snooping by asserting bits in register DWC3_GSBUSCFG0
> for data and descriptor

The description doesn't fully cover the change you made below, for example allocating multiple event buffers.  Please explain why you made such change.

> 
> Signed-off-by: Nikhil Badola <nikhil.badola at freescale.com>
> Signed-off-by: Rajesh Bhagat <rajesh.bhagat at freescale.com>
> Signed-off-by: yinbo.zhu <yinbo.zhu at nxp.com>
> ---
>  drivers/usb/dwc3/core.c | 71 ++++++++++++++++++++++++++++++++++++-------
> ------
>  drivers/usb/dwc3/core.h |  3 +++
>  drivers/usb/dwc3/host.c |  8 +++++-
>  3 files changed, 63 insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c index
> 02a534a..b51b0d8 100644
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
> @@ -90,6 +90,7 @@ static int dwc3_get_dr_mode(struct dwc3 *dwc)
> 
>  		if (IS_ENABLED(CONFIG_USB_DWC3_HOST))
>  			mode = USB_DR_MODE_HOST;
> +

Why are you adding a new line here?

>  		else if (IS_ENABLED(CONFIG_USB_DWC3_GADGET))
>  			mode = USB_DR_MODE_PERIPHERAL;
>  	}
> @@ -305,14 +306,27 @@ static void dwc3_free_event_buffers(struct dwc3
> *dwc)
>   */
>  static int dwc3_alloc_event_buffers(struct dwc3 *dwc, unsigned length)  {
> -	struct dwc3_event_buffer *evt;
> +	int                     num;
> +	int                     i;
> +
> +	num = DWC3_NUM_INT(dwc->hwparams.hwparams1);
> +	dwc->num_event_buffers = num;
> +
> +	dwc->ev_buffs = devm_kzalloc(dwc->dev, sizeof(*dwc->ev_buffs) * num,
> +			GFP_KERNEL);
> +	if (!dwc->ev_buffs)
> +		return -ENOMEM;
> 
> -	evt = dwc3_alloc_one_event_buffer(dwc, length);
> -	if (IS_ERR(evt)) {
> -		dev_err(dwc->dev, "can't allocate event buffer\n");
> -		return PTR_ERR(evt);
> +	for (i = 0; i < num; i++) {
> +		struct dwc3_event_buffer        *evt;
> +
> +		evt = dwc3_alloc_one_event_buffer(dwc, length);
> +		if (IS_ERR(evt)) {
> +			dev_err(dwc->dev, "can't allocate event buffer\n");
> +			return PTR_ERR(evt);
> +		}
> +		dwc->ev_buffs[i] = evt;
>  	}
> -	dwc->ev_buf = evt;
> 
>  	return 0;
>  }
> @@ -325,17 +339,25 @@ static int dwc3_alloc_event_buffers(struct dwc3
> *dwc, unsigned length)
>   */
>  static int dwc3_event_buffers_setup(struct dwc3 *dwc)  {
> -	struct dwc3_event_buffer	*evt;
> -
> -	evt = dwc->ev_buf;
> -	evt->lpos = 0;
> -	dwc3_writel(dwc->regs, DWC3_GEVNTADRLO(0),
> -			lower_32_bits(evt->dma));
> -	dwc3_writel(dwc->regs, DWC3_GEVNTADRHI(0),
> -			upper_32_bits(evt->dma));
> -	dwc3_writel(dwc->regs, DWC3_GEVNTSIZ(0),
> -			DWC3_GEVNTSIZ_SIZE(evt->length));
> -	dwc3_writel(dwc->regs, DWC3_GEVNTCOUNT(0), 0);
> +	struct dwc3_event_buffer        *evt;
> +	int                             n;
> +
> +	for (n = 0; n < dwc->num_event_buffers; n++) {
> +		evt = dwc->ev_buffs[n];
> +		dev_dbg(dwc->dev, "Event buf %p dma %08llx length %d\n",
> +				evt->buf, (unsigned long long) evt->dma,
> +				evt->length);
> +
> +		evt->lpos = 0;
> +
> +		dwc3_writel(dwc->regs, DWC3_GEVNTADRLO(n),
> +				lower_32_bits(evt->dma));
> +		dwc3_writel(dwc->regs, DWC3_GEVNTADRHI(n),
> +				upper_32_bits(evt->dma));
> +		dwc3_writel(dwc->regs, DWC3_GEVNTSIZ(n),
> +				DWC3_GEVNTSIZ_SIZE(evt->length));
> +		dwc3_writel(dwc->regs, DWC3_GEVNTCOUNT(n), 0);
> +	}
> 
>  	return 0;
>  }
> @@ -1181,6 +1203,7 @@ static void dwc3_check_params(struct dwc3 *dwc)
> static int dwc3_probe(struct platform_device *pdev)  {
>  	struct device		*dev = &pdev->dev;
> +	struct device_node      *node = dev->of_node;
>  	struct resource		*res;
>  	struct dwc3		*dwc;
> 
> @@ -1188,7 +1211,6 @@ static int dwc3_probe(struct platform_device *pdev)
> 
>  	void __iomem		*regs;
> 
> -	struct device_node      *node = dev->of_node;
>  	dwc = devm_kzalloc(dev, sizeof(*dwc), GFP_KERNEL);
>  	if (!dwc)
>  		return -ENOMEM;
> @@ -1260,6 +1282,19 @@ static int dwc3_probe(struct platform_device *pdev)
>  		goto err2;
>  	}
> 
> +	/* Change burst beat and outstanding pipelined transfers requests */
> +	dwc3_writel(dwc->regs, DWC3_GSBUSCFG0,
> +		(dwc3_readl(dwc->regs, DWC3_GSBUSCFG0) & ~0xff) | 0xf);
> +	dwc3_writel(dwc->regs, DWC3_GSBUSCFG1,
> +		dwc3_readl(dwc->regs, DWC3_GSBUSCFG1) | 0xf00);
> +
> +	/* Enable Snooping */
> +	if (node && of_dma_is_coherent(node)) {
> +		dwc3_writel(dwc->regs, DWC3_GSBUSCFG0,
> +		dwc3_readl(dwc->regs, DWC3_GSBUSCFG0) | 0x22220000);
> +		dev_dbg(dev, "enabled snooping for usb\n");
> +	}
> +
>  	ret = dwc3_get_dr_mode(dwc);
>  	if (ret)
>  		goto err3;
> diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h index
> b83388f..e075665 100644
> --- a/drivers/usb/dwc3/core.h
> +++ b/drivers/usb/dwc3/core.h
> @@ -29,6 +29,7 @@
>  #include <linux/debugfs.h>
>  #include <linux/wait.h>
>  #include <linux/workqueue.h>
> +#include <linux/of_address.h>
> 
>  #include <linux/usb/ch9.h>
>  #include <linux/usb/gadget.h>
> @@ -913,6 +914,7 @@ struct dwc3 {
>  	struct platform_device	*xhci;
>  	struct resource
> 	xhci_resources[DWC3_XHCI_RESOURCES_NUM];
> 
> +	struct dwc3_event_buffer **ev_buffs;
>  	struct dwc3_event_buffer *ev_buf;
>  	struct dwc3_ep		*eps[DWC3_ENDPOINTS_NUM];
> 
> @@ -946,6 +948,7 @@ struct dwc3 {
>  	u32			incrx_type[2];
>  	u32			irq_gadget;
>  	u32			nr_scratch;
> +	u32			num_event_buffers;
>  	u32			u1u2;
>  	u32			maximum_speed;
> 
> diff --git a/drivers/usb/dwc3/host.c b/drivers/usb/dwc3/host.c index
> 3e85616..0f2b86c 100644
> --- a/drivers/usb/dwc3/host.c
> +++ b/drivers/usb/dwc3/host.c
> @@ -93,8 +93,14 @@ int dwc3_host_init(struct dwc3 *dwc)
>  		dma_set_coherent_mask(&xhci->dev, dwc->dev-
> >coherent_dma_mask);
> 
>  	xhci->dev.parent = dwc->dev;
> -
>  	xhci->dev.dma_mask = dwc->dev->dma_mask;
> +	xhci->dev.dma_parms     = dwc->dev->dma_parms;
> +
> +	/* set DMA operations */
> +	if (dwc->dev->of_node && of_dma_is_coherent(dwc->dev->of_node)) {
> +		xhci->dev.archdata.dma_ops = dwc->dev->archdata.dma_ops;
> +		dev_dbg(dwc->dev, "set dma_ops for usb\n");
> +	}
> 
>  	dwc->xhci = xhci;
> 
> --
> 2.1.0.27.g96db324
> 
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