[PATCH 5/6] usb: musb: gadget: implement send_response

Paul Elder
2018-10-10T02:49:36Z

This patch implements a mechanism to signal the MUSB driver to reply to
a control OUT request with STALL or ACK.

Signed-off-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
drivers/usb/musb/musb_gadget_ep0.c | 41 ++++++++++++++++++++++++++++++
1 file changed, 41 insertions(+)

diff --git a/drivers/usb/musb/musb_gadget_ep0.c b/drivers/usb/musb/musb_gadget_ep0.c
index 91a5027b5c1f..f0ed1f7472a3 100644
--- a/drivers/usb/musb/musb_gadget_ep0.c
+++ b/drivers/usb/musb/musb_gadget_ep0.c
@@ -458,6 +458,25 @@ __acquires(musb->lock)
return handled;
}

+static int ep0_send_response(struct musb *musb, bool stall)
+{
+ void __iomem *regs = musb->control_ep->regs;
+ u16 ackpend;
+
+ if (musb->ep0_state != MUSB_EP0_STAGE_RX &&
+ musb->ep0_state != MUSB_EP0_STAGE_STATUSIN)
+ return -EINVAL;
+
+ ackpend = MUSB_CSR0_P_DATAEND
+ | MUSB_CSR0_P_SVDRXPKTRDY
+ | (stall ? MUSB_CSR0_P_SENDSTALL : 0);
+
+ musb_ep_select(musb->mregs, 0);
+ musb_writew(regs, MUSB_CSR0, ackpend);
+
+ return 0;
+}
+
/* we have an ep0out data packet
* Context: caller holds controller lock
*/
@@ -466,10 +485,13 @@ static void ep0_rxstate(struct musb *musb)
void __iomem *regs = musb->control_ep->regs;
struct musb_request *request;
struct usb_request *req;
+ struct usb_ep *ep;
u16 count, csr;
+ bool last_packet = false;

request = next_ep0_request(musb);
req = &request->request;
+ ep = &request->ep->end_point;

/* read packet and ack; or stall because of gadget driver bug:
* should have provided the rx buffer before setup() returned.
@@ -492,6 +514,7 @@ static void ep0_rxstate(struct musb *musb)
if (count < 64 || req->actual == req->length) {
musb->ep0_state = MUSB_EP0_STAGE_STATUSIN;
csr |= MUSB_CSR0_P_DATAEND;
+ last_packet = true;
} else
req = NULL;
} else
@@ -508,6 +531,10 @@ static void ep0_rxstate(struct musb *musb)
return;
musb->ackpend = 0;
}
+
+ if (last_packet && ep->delayed_status)
+ return;
+
musb_ep_select(musb->mregs, 0);
musb_writew(regs, MUSB_CSR0, csr);
}
@@ -991,6 +1018,19 @@ static int musb_g_ep0_dequeue(struct usb_ep *ep, struct usb_request *req)
return -EINVAL;
}

+static int musb_g_ep0_send_response(struct usb_ep *e, bool stall)
+{
+ struct musb_ep *ep = to_musb_ep(e);
+ struct musb *musb = ep->musb;
+ unsigned long flags;
+ int ret;
+
+ spin_lock_irqsave(&musb->lock, flags);
+ ret = ep0_send_response(musb, stall);
+ spin_unlock_irqrestore(&musb->lock, flags);
+ return ret;
+}
+
static int musb_g_ep0_halt(struct usb_ep *e, int value)
{
struct musb_ep *ep;
@@ -1059,4 +1099,5 @@ const struct usb_ep_ops musb_g_ep0_ops = {
.queue = musb_g_ep0_queue,
.dequeue = musb_g_ep0_dequeue,
.set_halt = musb_g_ep0_halt,
+ .send_response = musb_g_ep0_send_response,
};
--
2.18.0