[PATCH v2 5/6] usb: dwc3: ep0: Add chained TRB support

From: Kishon Vijay Abraham I
Date: Fri Jul 24 2015 - 02:47:44 EST


Add chained TRB support to ep0. Now TRB's can be chained just by
invoking _dwc3_ep0_start_trans_ with 'chain' parameter set to true.

Signed-off-by: Kishon Vijay Abraham I <kishon@xxxxxx>
---
drivers/usb/dwc3/ep0.c | 16 +++++++++++++---
drivers/usb/dwc3/gadget.c | 2 +-
2 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/dwc3/ep0.c b/drivers/usb/dwc3/ep0.c
index d1a2be1..6847afe 100644
--- a/drivers/usb/dwc3/ep0.c
+++ b/drivers/usb/dwc3/ep0.c
@@ -70,7 +70,10 @@ 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);
@@ -78,10 +81,17 @@ 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);
+
+ 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);
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index d97fcfa..2feed9e 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -2687,7 +2687,7 @@ int dwc3_gadget_init(struct dwc3 *dwc)
goto err0;
}

- dwc->ep0_trb = dma_alloc_coherent(dwc->dev, sizeof(*dwc->ep0_trb),
+ dwc->ep0_trb = dma_alloc_coherent(dwc->dev, sizeof(*dwc->ep0_trb) * 2,
&dwc->ep0_trb_addr, GFP_KERNEL);
if (!dwc->ep0_trb) {
dev_err(dwc->dev, "failed to allocate ep0 trb\n");
--
1.7.9.5

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