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usb: dwc2: gadget: EP 0 specific DDMA programming
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Add dwc2_gadget_set_ep0_desc_chain() function to switch between EP0 DDMA
chains depend on the stage of control transfer.

Include EP0 DDMA chain selection during ep_queue called from
dwc2_hsotg_enqueue_setup() for setup stage. Selecting and filling DDMA
chain for status phase as well - add calls of
dwc2_gadget_set_ep0_desc_chain() and
dwc2_gadget_config_nonisoc_xfer_ddma() functions.

Signed-off-by: Vahram Aharonyan <vahrama@synopsys.com>
Signed-off-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
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Vahram Aharonyan authored and Felipe Balbi committed Nov 18, 2016
1 parent 8ad0733 commit e02f9aa
Showing 1 changed file with 161 additions and 5 deletions.
166 changes: 161 additions & 5 deletions drivers/usb/dwc2/gadget.c
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Original file line number Diff line number Diff line change
Expand Up @@ -627,6 +627,114 @@ static unsigned int dwc2_gadget_get_chain_limit(struct dwc2_hsotg_ep *hs_ep)
return maxsize;
}

/*
* dwc2_gadget_get_desc_params - get DMA descriptor parameters.
* @hs_ep: The endpoint
* @mask: RX/TX bytes mask to be defined
*
* Returns maximum data payload for one descriptor after analyzing endpoint
* characteristics.
* DMA descriptor transfer bytes limit depends on EP type:
* Control out - MPS,
* Isochronous - descriptor rx/tx bytes bitfield limit,
* Control In/Bulk/Interrupt - multiple of mps. This will allow to not
* have concatenations from various descriptors within one packet.
*
* Selects corresponding mask for RX/TX bytes as well.
*/
static u32 dwc2_gadget_get_desc_params(struct dwc2_hsotg_ep *hs_ep, u32 *mask)
{
u32 mps = hs_ep->ep.maxpacket;
int dir_in = hs_ep->dir_in;
u32 desc_size = 0;

if (!hs_ep->index && !dir_in) {
desc_size = mps;
*mask = DEV_DMA_NBYTES_MASK;
} else if (hs_ep->isochronous) {
if (dir_in) {
desc_size = DEV_DMA_ISOC_TX_NBYTES_LIMIT;
*mask = DEV_DMA_ISOC_TX_NBYTES_MASK;
} else {
desc_size = DEV_DMA_ISOC_RX_NBYTES_LIMIT;
*mask = DEV_DMA_ISOC_RX_NBYTES_MASK;
}
} else {
desc_size = DEV_DMA_NBYTES_LIMIT;
*mask = DEV_DMA_NBYTES_MASK;

/* Round down desc_size to be mps multiple */
desc_size -= desc_size % mps;
}

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,
dma_addr_t dma_buff,
unsigned int len)
{
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;
u32 mask = 0;
int i;

maxsize = dwc2_gadget_get_desc_params(hs_ep, &mask);

hs_ep->desc_count = (len / maxsize) +
((len % maxsize) ? 1 : 0);
if (len == 0)
hs_ep->desc_count = 1;

for (i = 0; i < hs_ep->desc_count; ++i) {
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 |= (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 (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 << DEV_DMA_NBYTES_SHIFT & mask;
desc->buf = dma_buff + offset;
}

desc->status &= ~DEV_DMA_BUFF_STS_MASK;
desc->status |= (DEV_DMA_BUFF_STS_HREADY
<< DEV_DMA_BUFF_STS_SHIFT);
desc++;
}
}

/**
* dwc2_hsotg_start_req - start a USB request from an endpoint's queue
* @hsotg: The controller state.
Expand Down Expand Up @@ -926,6 +1034,41 @@ static bool dwc2_gadget_target_frame_elapsed(struct dwc2_hsotg_ep *hs_ep)
return false;
}

/*
* dwc2_gadget_set_ep0_desc_chain - Set EP's desc chain pointers
* @hsotg: The driver state
* @hs_ep: the ep descriptor chain is for
*
* Called to update EP0 structure's pointers depend on stage of
* control transfer.
*/
static int dwc2_gadget_set_ep0_desc_chain(struct dwc2_hsotg *hsotg,
struct dwc2_hsotg_ep *hs_ep)
{
switch (hsotg->ep0_state) {
case DWC2_EP0_SETUP:
case DWC2_EP0_STATUS_OUT:
hs_ep->desc_list = hsotg->setup_desc[0];
hs_ep->desc_list_dma = hsotg->setup_desc_dma[0];
break;
case DWC2_EP0_DATA_IN:
case DWC2_EP0_STATUS_IN:
hs_ep->desc_list = hsotg->ctrl_in_desc;
hs_ep->desc_list_dma = hsotg->ctrl_in_desc_dma;
break;
case DWC2_EP0_DATA_OUT:
hs_ep->desc_list = hsotg->ctrl_out_desc;
hs_ep->desc_list_dma = hsotg->ctrl_out_desc_dma;
break;
default:
dev_err(hsotg->dev, "invalid EP 0 state in queue %d\n",
hsotg->ep0_state);
return -EINVAL;
}

return 0;
}

static int dwc2_hsotg_ep_queue(struct usb_ep *ep, struct usb_request *req,
gfp_t gfp_flags)
{
Expand Down Expand Up @@ -961,6 +1104,12 @@ static int dwc2_hsotg_ep_queue(struct usb_ep *ep, struct usb_request *req,
if (ret)
return ret;
}
/* If using descriptor DMA configure EP0 descriptor chain pointers */
if (using_desc_dma(hs) && !hs_ep->index) {
ret = dwc2_gadget_set_ep0_desc_chain(hs, hs_ep);
if (ret)
return ret;
}

first = list_empty(&hs_ep->queue);
list_add_tail(&hs_req->queue, &hs_ep->queue);
Expand Down Expand Up @@ -1529,14 +1678,21 @@ static void dwc2_hsotg_program_zlp(struct dwc2_hsotg *hsotg,

if (hs_ep->dir_in)
dev_dbg(hsotg->dev, "Sending zero-length packet on ep%d\n",
index);
index);
else
dev_dbg(hsotg->dev, "Receiving zero-length packet on ep%d\n",
index);
index);
if (using_desc_dma(hsotg)) {
/* Not specific buffer needed for ep0 ZLP */
dma_addr_t dma = hs_ep->desc_list_dma;

dwc2_writel(DXEPTSIZ_MC(1) | DXEPTSIZ_PKTCNT(1) |
DXEPTSIZ_XFERSIZE(0), hsotg->regs +
epsiz_reg);
dwc2_gadget_set_ep0_desc_chain(hsotg, hs_ep);
dwc2_gadget_config_nonisoc_xfer_ddma(hs_ep, dma, 0);
} else {
dwc2_writel(DXEPTSIZ_MC(1) | DXEPTSIZ_PKTCNT(1) |
DXEPTSIZ_XFERSIZE(0), hsotg->regs +
epsiz_reg);
}

ctrl = dwc2_readl(hsotg->regs + epctl_reg);
ctrl |= DXEPCTL_CNAK; /* clear NAK set by core */
Expand Down

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