Commit 10209abe authored by Andrzej Pietrasiewicz's avatar Andrzej Pietrasiewicz Committed by Felipe Balbi

usb: dwc2: gadget: Add scatter-gather mode

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: default avatarAndrzej Pietrasiewicz <andrzej.p@samsung.com>
[mszyprow: fixed null pointer issue, rewrote commit message]
Signed-off-by: default avatarMarek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: default avatarFelipe Balbi <felipe.balbi@linux.intel.com>
parent 1ff767bf
......@@ -768,22 +768,13 @@ static u32 dwc2_gadget_get_desc_params(struct dwc2_hsotg_ep *hs_ep, u32 *mask)
return desc_size;
}
/*
* dwc2_gadget_config_nonisoc_xfer_ddma - prepare non ISOC DMA desc chain.
* @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,
static void dwc2_gadget_fill_nonisoc_xfer_ddma_one(struct dwc2_hsotg_ep *hs_ep,
struct dwc2_dma_desc **desc,
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;
struct dwc2_dma_desc *desc = hs_ep->desc_list;
u32 mps = hs_ep->ep.maxpacket;
u32 maxsize = 0;
u32 offset = 0;
......@@ -798,39 +789,77 @@ static void dwc2_gadget_config_nonisoc_xfer_ddma(struct dwc2_hsotg_ep *hs_ep,
hs_ep->desc_count = 1;
for (i = 0; i < hs_ep->desc_count; ++i) {
desc->status = 0;
desc->status |= (DEV_DMA_BUFF_STS_HBUSY
(*desc)->status = 0;
(*desc)->status |= (DEV_DMA_BUFF_STS_HBUSY
<< DEV_DMA_BUFF_STS_SHIFT);
if (len > maxsize) {
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 <<
DEV_DMA_NBYTES_SHIFT & mask);
desc->buf = dma_buff + offset;
(*desc)->status |=
maxsize << DEV_DMA_NBYTES_SHIFT & mask;
(*desc)->buf = dma_buff + offset;
len -= maxsize;
offset += maxsize;
} else {
desc->status |= (DEV_DMA_L | DEV_DMA_IOC);
if (true_last)
(*desc)->status |= (DEV_DMA_L | DEV_DMA_IOC);
if (dir_in)
desc->status |= (len % mps) ? DEV_DMA_SHORT :
((hs_ep->send_zlp) ? DEV_DMA_SHORT : 0);
if (len > maxsize)
dev_err(hsotg->dev, "wrong len %d\n", len);
(*desc)->status |= (len % mps) ? DEV_DMA_SHORT :
((hs_ep->send_zlp && true_last) ?
DEV_DMA_SHORT : 0);
desc->status |=
(*desc)->status |=
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_HREADY
(*desc)->status &= ~DEV_DMA_BUFF_STS_MASK;
(*desc)->status |= (DEV_DMA_BUFF_STS_HREADY
<< 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;
}
/*
......@@ -944,7 +973,13 @@ static void dwc2_gadget_start_isoc_ddma(struct dwc2_hsotg_ep *hs_ep)
hs_ep->next_desc = 0;
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);
if (ret)
break;
......@@ -1100,7 +1135,7 @@ static void dwc2_hsotg_start_req(struct dwc2_hsotg *hsotg,
offset = ureq->actual;
/* 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);
/* 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 (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);
}
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",
index);
if (using_desc_dma(hsotg)) {
/* Not specific buffer needed for ep0 ZLP */
dma_addr_t dma = hs_ep->desc_list_dma;
if (!index)
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 {
dwc2_writel(hsotg, DXEPTSIZ_MC(1) | DXEPTSIZ_PKTCNT(1) |
DXEPTSIZ_XFERSIZE(0),
......@@ -4386,6 +4426,7 @@ static int dwc2_hsotg_udc_start(struct usb_gadget *gadget,
hsotg->enabled = 0;
spin_unlock_irqrestore(&hsotg->lock, flags);
gadget->sg_supported = using_desc_dma(hsotg);
dev_info(hsotg->dev, "bound driver %s\n", driver->driver.name);
return 0;
......
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