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usb: dwc2: gadget: Add scatter-gather mode

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This patch adds support for transferring requests, which are
non-contiguous in physical memory, i.e. the data buffer is described by
a scatter-list. This allows transferring large requests without relying
on error-prone contiguous buffer allocations. This way of allocating
requests is already implemented in functionfs and TCM USB functions and
automatically used if UDC driver advertises scatter-gather suppport.

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
[mszyprow: fixed null pointer issue, rewrote commit message]
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
This commit is contained in:
Andrzej Pietrasiewicz 2019-01-21 14:44:47 +01:00 committed by Felipe Balbi
parent 1ff767bfa5
commit 10209abe87
1 changed files with 77 additions and 36 deletions
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113
drivers/usb/dwc2/gadget.c
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@ -768,22 +768,13 @@ static u32 dwc2_gadget_get_desc_params(struct dwc2_hsotg_ep *hs_ep, u32 *mask)
return desc_size; return desc_size;
} }
/* static void dwc2_gadget_fill_nonisoc_xfer_ddma_one(struct dwc2_hsotg_ep *hs_ep,
* dwc2_gadget_config_nonisoc_xfer_ddma - prepare non ISOC DMA desc chain. struct dwc2_dma_desc **desc,
* @hs_ep: The endpoint
* @dma_buff: DMA address to use
* @len: Length of the transfer
*
* This function will iterate over descriptor chain and fill its entries
* with corresponding information based on transfer data.
*/
static void dwc2_gadget_config_nonisoc_xfer_ddma(struct dwc2_hsotg_ep *hs_ep,
dma_addr_t dma_buff, dma_addr_t dma_buff,
unsigned int len) unsigned int len,
bool true_last)
{ {
struct dwc2_hsotg *hsotg = hs_ep->parent;
int dir_in = hs_ep->dir_in; int dir_in = hs_ep->dir_in;
struct dwc2_dma_desc *desc = hs_ep->desc_list;
u32 mps = hs_ep->ep.maxpacket; u32 mps = hs_ep->ep.maxpacket;
u32 maxsize = 0; u32 maxsize = 0;
u32 offset = 0; u32 offset = 0;
@ -798,41 +789,79 @@ static void dwc2_gadget_config_nonisoc_xfer_ddma(struct dwc2_hsotg_ep *hs_ep,
hs_ep->desc_count = 1; hs_ep->desc_count = 1;
for (i = 0; i < hs_ep->desc_count; ++i) { for (i = 0; i < hs_ep->desc_count; ++i) {
desc->status = 0; (*desc)->status = 0;
desc->status |= (DEV_DMA_BUFF_STS_HBUSY (*desc)->status |= (DEV_DMA_BUFF_STS_HBUSY
<< DEV_DMA_BUFF_STS_SHIFT); << DEV_DMA_BUFF_STS_SHIFT);
if (len > maxsize) { if (len > maxsize) {
if (!hs_ep->index && !dir_in) if (!hs_ep->index && !dir_in)
desc->status |= (DEV_DMA_L | DEV_DMA_IOC); (*desc)->status |= (DEV_DMA_L | DEV_DMA_IOC);
desc->status |= (maxsize << (*desc)->status |=
DEV_DMA_NBYTES_SHIFT & mask); maxsize << DEV_DMA_NBYTES_SHIFT & mask;
desc->buf = dma_buff + offset; (*desc)->buf = dma_buff + offset;
len -= maxsize; len -= maxsize;
offset += maxsize; offset += maxsize;
} else { } else {
desc->status |= (DEV_DMA_L | DEV_DMA_IOC); if (true_last)
(*desc)->status |= (DEV_DMA_L | DEV_DMA_IOC);
if (dir_in) if (dir_in)
desc->status |= (len % mps) ? DEV_DMA_SHORT : (*desc)->status |= (len % mps) ? DEV_DMA_SHORT :
((hs_ep->send_zlp) ? DEV_DMA_SHORT : 0); ((hs_ep->send_zlp && true_last) ?
if (len > maxsize) DEV_DMA_SHORT : 0);
dev_err(hsotg->dev, "wrong len %d\n", len);
desc->status |= (*desc)->status |=
len << DEV_DMA_NBYTES_SHIFT & mask; len << DEV_DMA_NBYTES_SHIFT & mask;
desc->buf = dma_buff + offset; (*desc)->buf = dma_buff + offset;
} }
desc->status &= ~DEV_DMA_BUFF_STS_MASK; (*desc)->status &= ~DEV_DMA_BUFF_STS_MASK;
desc->status |= (DEV_DMA_BUFF_STS_HREADY (*desc)->status |= (DEV_DMA_BUFF_STS_HREADY
<< DEV_DMA_BUFF_STS_SHIFT); << DEV_DMA_BUFF_STS_SHIFT);
desc++; (*desc)++;
} }
} }
/*
* dwc2_gadget_config_nonisoc_xfer_ddma - prepare non ISOC DMA desc chain.
* @hs_ep: The endpoint
* @ureq: Request to transfer
* @offset: offset in bytes
* @len: Length of the transfer
*
* This function will iterate over descriptor chain and fill its entries
* with corresponding information based on transfer data.
*/
static void dwc2_gadget_config_nonisoc_xfer_ddma(struct dwc2_hsotg_ep *hs_ep,
struct usb_request *ureq,
unsigned int offset,
unsigned int len)
{
struct dwc2_dma_desc *desc = hs_ep->desc_list;
struct scatterlist *sg;
int i;
u8 desc_count = 0;
/* non-DMA sg buffer */
if (!ureq->num_sgs) {
dwc2_gadget_fill_nonisoc_xfer_ddma_one(hs_ep, &desc,
ureq->dma + offset, len, true);
return;
}
/* DMA sg buffer */
for_each_sg(ureq->sg, sg, ureq->num_sgs, i) {
dwc2_gadget_fill_nonisoc_xfer_ddma_one(hs_ep, &desc,
sg_dma_address(sg) + sg->offset, sg_dma_len(sg),
sg_is_last(sg));
desc_count += hs_ep->desc_count;
}
hs_ep->desc_count = desc_count;
}
/* /*
* dwc2_gadget_fill_isoc_desc - fills next isochronous descriptor in chain. * dwc2_gadget_fill_isoc_desc - fills next isochronous descriptor in chain.
* @hs_ep: The isochronous endpoint. * @hs_ep: The isochronous endpoint.
@ -944,7 +973,13 @@ static void dwc2_gadget_start_isoc_ddma(struct dwc2_hsotg_ep *hs_ep)
hs_ep->next_desc = 0; hs_ep->next_desc = 0;
list_for_each_entry_safe(hs_req, treq, &hs_ep->queue, queue) { list_for_each_entry_safe(hs_req, treq, &hs_ep->queue, queue) {
ret = dwc2_gadget_fill_isoc_desc(hs_ep, hs_req->req.dma, dma_addr_t dma_addr = hs_req->req.dma;
if (hs_req->req.num_sgs) {
WARN_ON(hs_req->req.num_sgs > 1);
dma_addr = sg_dma_address(hs_req->req.sg);
}
ret = dwc2_gadget_fill_isoc_desc(hs_ep, dma_addr,
hs_req->req.length); hs_req->req.length);
if (ret) if (ret)
break; break;
@ -1100,7 +1135,7 @@ static void dwc2_hsotg_start_req(struct dwc2_hsotg *hsotg,
offset = ureq->actual; offset = ureq->actual;
/* Fill DDMA chain entries */ /* Fill DDMA chain entries */
dwc2_gadget_config_nonisoc_xfer_ddma(hs_ep, ureq->dma + offset, dwc2_gadget_config_nonisoc_xfer_ddma(hs_ep, ureq, offset,
length); length);
/* write descriptor chain address to control register */ /* write descriptor chain address to control register */
@ -1399,7 +1434,13 @@ static int dwc2_hsotg_ep_queue(struct usb_ep *ep, struct usb_request *req,
*/ */
if (using_desc_dma(hs) && hs_ep->isochronous) { if (using_desc_dma(hs) && hs_ep->isochronous) {
if (hs_ep->target_frame != TARGET_FRAME_INITIAL) { if (hs_ep->target_frame != TARGET_FRAME_INITIAL) {
dwc2_gadget_fill_isoc_desc(hs_ep, hs_req->req.dma, dma_addr_t dma_addr = hs_req->req.dma;
if (hs_req->req.num_sgs) {
WARN_ON(hs_req->req.num_sgs > 1);
dma_addr = sg_dma_address(hs_req->req.sg);
}
dwc2_gadget_fill_isoc_desc(hs_ep, dma_addr,
hs_req->req.length); hs_req->req.length);
} }
return 0; return 0;
@ -1987,13 +2028,12 @@ static void dwc2_hsotg_program_zlp(struct dwc2_hsotg *hsotg,
dev_dbg(hsotg->dev, "Receiving zero-length packet on ep%d\n", dev_dbg(hsotg->dev, "Receiving zero-length packet on ep%d\n",
index); index);
if (using_desc_dma(hsotg)) { if (using_desc_dma(hsotg)) {
/* Not specific buffer needed for ep0 ZLP */
dma_addr_t dma = hs_ep->desc_list_dma;
if (!index) if (!index)
dwc2_gadget_set_ep0_desc_chain(hsotg, hs_ep); dwc2_gadget_set_ep0_desc_chain(hsotg, hs_ep);
dwc2_gadget_config_nonisoc_xfer_ddma(hs_ep, dma, 0); /* Not specific buffer needed for ep0 ZLP */
dwc2_gadget_fill_nonisoc_xfer_ddma_one(hs_ep, &hs_ep->desc_list,
hs_ep->desc_list_dma, 0, true);
} else { } else {
dwc2_writel(hsotg, DXEPTSIZ_MC(1) | DXEPTSIZ_PKTCNT(1) | dwc2_writel(hsotg, DXEPTSIZ_MC(1) | DXEPTSIZ_PKTCNT(1) |
DXEPTSIZ_XFERSIZE(0), DXEPTSIZ_XFERSIZE(0),
@ -4386,6 +4426,7 @@ static int dwc2_hsotg_udc_start(struct usb_gadget *gadget,
hsotg->enabled = 0; hsotg->enabled = 0;
spin_unlock_irqrestore(&hsotg->lock, flags); spin_unlock_irqrestore(&hsotg->lock, flags);
gadget->sg_supported = using_desc_dma(hsotg);
dev_info(hsotg->dev, "bound driver %s\n", driver->driver.name); dev_info(hsotg->dev, "bound driver %s\n", driver->driver.name);
return 0; return 0;