[U-Boot] [u-boot 32/40] usb: dwc3: Add chained TRB support for ep0

[Lukasz Majewski <l.majewski@samsung.com>]

Hi Kishon,

> dwc3 can do only max packet aligned transfers. So in case request
> length is not max packet aligned and is bigger than
> DWC3_EP0_BOUNCE_SIZE two chained TRBs is required to handle the
> transfer.
> 
> Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
> ---
>  drivers/usb/dwc3/ep0.c    |   72
> +++++++++++++++++++++++++++++++++------------
> drivers/usb/dwc3/gadget.c |    2 +- 2 files changed, 55
> insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/usb/dwc3/ep0.c b/drivers/usb/dwc3/ep0.c
> index fce2558..c2fe0ec 100644
> --- a/drivers/usb/dwc3/ep0.c
> +++ b/drivers/usb/dwc3/ep0.c
> @@ -48,7 +48,7 @@ static const char *dwc3_ep0_state_string(enum
> dwc3_ep0_state state) }
>  
>  static int dwc3_ep0_start_trans(struct dwc3 *dwc, u8 epnum,
> dma_addr_t buf_dma,
> -		u32 len, u32 type)
> +				u32 len, u32 type, unsigned chain)
>  {
>  	struct dwc3_gadget_ep_cmd_params params;
>  	struct dwc3_trb			*trb;
> @@ -62,7 +62,10 @@ static int dwc3_ep0_start_trans(struct dwc3 *dwc,
> u8 epnum, dma_addr_t buf_dma, return 0;
>  	}
>  
> -	trb = dwc->ep0_trb;
> +	trb = &dwc->ep0_trb[dep->free_slot];
> +
> +	if (chain)
> +		dep->free_slot++;
>  
>  	trb->bpl = lower_32_bits(buf_dma);
>  	trb->bph = upper_32_bits(buf_dma);
> @@ -70,13 +73,20 @@ static int dwc3_ep0_start_trans(struct dwc3 *dwc,
> u8 epnum, dma_addr_t buf_dma, trb->ctrl = type;
>  
>  	trb->ctrl |= (DWC3_TRB_CTRL_HWO
> -			| DWC3_TRB_CTRL_LST
> -			| DWC3_TRB_CTRL_IOC
>  			| DWC3_TRB_CTRL_ISP_IMI);
>  
> +	if (chain)
> +		trb->ctrl |= DWC3_TRB_CTRL_CHN;
> +	else
> +		trb->ctrl |= (DWC3_TRB_CTRL_IOC
> +				| DWC3_TRB_CTRL_LST);
> +
>  	dwc3_flush_cache((int)buf_dma, len);
>  	dwc3_flush_cache((int)trb, sizeof(*trb));
>  
> +	if (chain)
> +		return 0;
> +
>  	memset(&params, 0, sizeof(params));
>  	params.param0 = upper_32_bits(dwc->ep0_trb_addr);
>  	params.param1 = lower_32_bits(dwc->ep0_trb_addr);
> @@ -289,7 +299,7 @@ void dwc3_ep0_out_start(struct dwc3 *dwc)
>  	int				ret;
>  
>  	ret = dwc3_ep0_start_trans(dwc, 0, dwc->ctrl_req_addr, 8,
> -			DWC3_TRBCTL_CONTROL_SETUP);
> +				   DWC3_TRBCTL_CONTROL_SETUP, 0);
>  	WARN_ON(ret < 0);
>  }
>  
> @@ -799,6 +809,23 @@ static void dwc3_ep0_complete_data(struct dwc3
> *dwc, 
>  	maxp = ep0->endpoint.maxpacket;
>  
> +	/* Handle the first TRB before handling the bounce buffer if
> the request

	Minor comment - please fix above comment.

> +	 * length is greater than the bounce buffer size
> +	 */
> +	if (!IS_ALIGNED(ur->length, maxp) &&
> +	    ur->length > DWC3_EP0_BOUNCE_SIZE) {
> +		transfer_size = (ur->length / maxp) * maxp;
> +		transferred = transfer_size - length;
> +		buf = (u8 *)buf + transferred;
> +		ur->actual += transferred;
> +
> +		trb++;
> +		dwc3_flush_cache((int)trb, sizeof(*trb));
> +		length = trb->size & DWC3_TRB_SIZE_MASK;
> +
> +		ep0->free_slot = 0;
> +	}
> +
>  	if (dwc->ep0_bounced) {
>  		transfer_size = roundup((ur->length - transfer_size),
>  					maxp);
> @@ -827,7 +854,7 @@ static void dwc3_ep0_complete_data(struct dwc3
> *dwc, 
>  			ret = dwc3_ep0_start_trans(dwc, epnum,
>  					dwc->ctrl_req_addr, 0,
> -					DWC3_TRBCTL_CONTROL_DATA);
> +					DWC3_TRBCTL_CONTROL_DATA, 0);
>  			WARN_ON(ret < 0);
>  		}
>  	}
> @@ -908,11 +935,11 @@ static void __dwc3_ep0_do_control_data(struct
> dwc3 *dwc, 
>  	if (req->request.length == 0) {
>  		ret = dwc3_ep0_start_trans(dwc, dep->number,
> -				dwc->ctrl_req_addr, 0,
> -				DWC3_TRBCTL_CONTROL_DATA);
> -	} else if (!IS_ALIGNED(req->request.length,
> dep->endpoint.maxpacket)
> -			&& (dep->number == 0)) {
> -		u32	transfer_size;
> +					   dwc->ctrl_req_addr, 0,
> +					   DWC3_TRBCTL_CONTROL_DATA,
> 0);
> +	} else if (!IS_ALIGNED(req->request.length,
> dep->endpoint.maxpacket) &&
> +			(dep->number == 0)) {
> +		u32	transfer_size = 0;
>  		u32	maxpacket;
>  
>  		ret = usb_gadget_map_request(&dwc->gadget,
> &req->request, @@ -922,10 +949,18 @@ static void
> __dwc3_ep0_do_control_data(struct dwc3 *dwc, return;
>  		}
>  
> -		WARN_ON(req->request.length > DWC3_EP0_BOUNCE_SIZE);
> -
>  		maxpacket = dep->endpoint.maxpacket;
> -		transfer_size = roundup(req->request.length,
> maxpacket);
> +		if (req->request.length > DWC3_EP0_BOUNCE_SIZE) {
> +			transfer_size = (req->request.length /
> maxpacket) *
> +						maxpacket;
> +			ret = dwc3_ep0_start_trans(dwc, dep->number,
> +						   req->request.dma,
> +						   transfer_size,
> +
> DWC3_TRBCTL_CONTROL_DATA, 1);
> +		}
> +
> +		transfer_size = roundup((req->request.length -
> transfer_size),
> +					maxpacket);
>  
>  		dwc->ep0_bounced = true;
>  
> @@ -935,8 +970,8 @@ static void __dwc3_ep0_do_control_data(struct
> dwc3 *dwc,
>  		 * TRBs to handle the transfer.
>  		 */
>  		ret = dwc3_ep0_start_trans(dwc, dep->number,
> -				dwc->ep0_bounce_addr, transfer_size,
> -				DWC3_TRBCTL_CONTROL_DATA);
> +					   dwc->ep0_bounce_addr,
> transfer_size,
> +					   DWC3_TRBCTL_CONTROL_DATA,
> 0); } else {
>  		ret = usb_gadget_map_request(&dwc->gadget,
> &req->request, dep->number);
> @@ -946,7 +981,8 @@ static void __dwc3_ep0_do_control_data(struct
> dwc3 *dwc, }
>  
>  		ret = dwc3_ep0_start_trans(dwc, dep->number,
> req->request.dma,
> -				req->request.length,
> DWC3_TRBCTL_CONTROL_DATA);
> +					   req->request.length,
> +					   DWC3_TRBCTL_CONTROL_DATA,
> 0); }
>  
>  	WARN_ON(ret < 0);
> @@ -961,7 +997,7 @@ static int dwc3_ep0_start_control_status(struct
> dwc3_ep *dep) : DWC3_TRBCTL_CONTROL_STATUS2;
>  
>  	return dwc3_ep0_start_trans(dwc, dep->number,
> -			dwc->ctrl_req_addr, 0, type);
> +			dwc->ctrl_req_addr, 0, type, 0);
>  }
>  
>  static void __dwc3_ep0_do_control_status(struct dwc3 *dwc, struct
> dwc3_ep *dep) diff --git a/drivers/usb/dwc3/gadget.c
> b/drivers/usb/dwc3/gadget.c index b68b6a4..01bc83b 100644
> --- a/drivers/usb/dwc3/gadget.c
> +++ b/drivers/usb/dwc3/gadget.c
> @@ -2580,7 +2580,7 @@ int dwc3_gadget_init(struct dwc3 *dwc)
>  		goto err0;
>  	}
>  
> -	dwc->ep0_trb = dma_alloc_coherent(sizeof(*dwc->ep0_trb),
> +	dwc->ep0_trb = dma_alloc_coherent(sizeof(*dwc->ep0_trb) * 2,
>  					  (unsigned long
> *)&dwc->ep0_trb_addr); if (!dwc->ep0_trb) {
>  		dev_err(dwc->dev, "failed to allocate ep0 trb\n");

Apart minor comment issue,

Reviewed-by: Lukasz Majewski <l.majewski@samsung.com>

-- 
Best regards,

Lukasz Majewski

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