usb: gadget: mv_udc: rewrite queue_dtd according to spec

Rewrite function queue_dtd according to ChipIdea's reference manual.
Remove all unnecessary logic, it will enhance the performance.

Signed-off-by: Neil Zhang <zhangwm@marvell.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

diff --git a/drivers/usb/gadget/mv_udc_core.c b/drivers/usb/gadget/mv_udc_core.c
index 635ee47..0ad321d 100644 (file)
--- a/drivers/usb/gadget/mv_udc_core.c
+++ b/drivers/usb/gadget/mv_udc_core.c
@@ -276,11 +276,12 @@ static void done(struct mv_ep *ep, struct mv_req *req, int status)
 
 static int queue_dtd(struct mv_ep *ep, struct mv_req *req)
 {
-       u32 tmp, epstatus, bit_pos, direction;
        struct mv_udc *udc;
        struct mv_dqh *dqh;
+       u32 bit_pos, direction;
+       u32 usbcmd, epstatus;
        unsigned int loops;
-       int readsafe, retval = 0;
+       int retval = 0;
 
        udc = ep->udc;
        direction = ep_dir(ep);
@@ -293,30 +294,18 @@ static int queue_dtd(struct mv_ep *ep, struct mv_req *req)
                lastreq = list_entry(ep->queue.prev, struct mv_req, queue);
                lastreq->tail->dtd_next =
                        req->head->td_dma & EP_QUEUE_HEAD_NEXT_POINTER_MASK;
-               if (readl(&udc->op_regs->epprime) & bit_pos) {
-                       loops = LOOPS(PRIME_TIMEOUT);
-                       while (readl(&udc->op_regs->epprime) & bit_pos) {
-                               if (loops == 0) {
-                                       retval = -ETIME;
-                                       goto done;
-                               }
-                               udelay(LOOPS_USEC);
-                               loops--;
-                       }
-                       if (readl(&udc->op_regs->epstatus) & bit_pos)
-                               goto done;
-               }
-               readsafe = 0;
+
+               wmb();
+
+               if (readl(&udc->op_regs->epprime) & bit_pos)
+                       goto done;
+
                loops = LOOPS(READSAFE_TIMEOUT);
-               while (readsafe == 0) {
-                       if (loops == 0) {
-                               retval = -ETIME;
-                               goto done;
-                       }
+               while (1) {
                        /* start with setting the semaphores */
-                       tmp = readl(&udc->op_regs->usbcmd);
-                       tmp |= USBCMD_ATDTW_TRIPWIRE_SET;
-                       writel(tmp, &udc->op_regs->usbcmd);
+                       usbcmd = readl(&udc->op_regs->usbcmd);
+                       usbcmd |= USBCMD_ATDTW_TRIPWIRE_SET;
+                       writel(usbcmd, &udc->op_regs->usbcmd);
 
                        /* read the endpoint status */
                        epstatus = readl(&udc->op_regs->epstatus) & bit_pos;
@@ -329,98 +318,46 @@ static int queue_dtd(struct mv_ep *ep, struct mv_req *req)
                         * primed.
                         */
                        if (readl(&udc->op_regs->usbcmd)
-                               & USBCMD_ATDTW_TRIPWIRE_SET) {
-                               readsafe = 1;
-                       }
+                               & USBCMD_ATDTW_TRIPWIRE_SET)
+                               break;
+
                        loops--;
+                       if (loops == 0) {
+                               dev_err(&udc->dev->dev,
+                                       "Timeout for ATDTW_TRIPWIRE...\n");
+                               retval = -ETIME;
+                               goto done;
+                       }
                        udelay(LOOPS_USEC);
                }
 
                /* Clear the semaphore */
-               tmp = readl(&udc->op_regs->usbcmd);
-               tmp &= USBCMD_ATDTW_TRIPWIRE_CLEAR;
-               writel(tmp, &udc->op_regs->usbcmd);
-
-               /* If endpoint is not active, we activate it now. */
-               if (!epstatus) {
-                       if (direction == EP_DIR_IN) {
-                               struct mv_dtd *curr_dtd = dma_to_virt(
-                                       &udc->dev->dev, dqh->curr_dtd_ptr);
-
-                               loops = LOOPS(DTD_TIMEOUT);
-                               while (curr_dtd->size_ioc_sts
-                                       & DTD_STATUS_ACTIVE) {
-                                       if (loops == 0) {
-                                               retval = -ETIME;
-                                               goto done;
-                                       }
-                                       loops--;
-                                       udelay(LOOPS_USEC);
-                               }
-                       }
-                       /* No other transfers on the queue */
+               usbcmd = readl(&udc->op_regs->usbcmd);
+               usbcmd &= USBCMD_ATDTW_TRIPWIRE_CLEAR;
+               writel(usbcmd, &udc->op_regs->usbcmd);
 
-                       /* Write dQH next pointer and terminate bit to 0 */
-                       dqh->next_dtd_ptr = req->head->td_dma
+               if (epstatus)
+                       goto done;
+       }
+
+       /* Write dQH next pointer and terminate bit to 0 */
+       dqh->next_dtd_ptr = req->head->td_dma
                                & EP_QUEUE_HEAD_NEXT_POINTER_MASK;
-                       dqh->size_ioc_int_sts = 0;
 
-                       /*
-                        * Ensure that updates to the QH will
-                        * occur before priming.
-                        */
-                       wmb();
+       /* clear active and halt bit, in case set from a previous error */
+       dqh->size_ioc_int_sts &= ~(DTD_STATUS_ACTIVE | DTD_STATUS_HALTED);
 
-                       /* Prime the Endpoint */
-                       writel(bit_pos, &udc->op_regs->epprime);
-               }
-       } else {
-               /* Write dQH next pointer and terminate bit to 0 */
-               dqh->next_dtd_ptr = req->head->td_dma
-                       & EP_QUEUE_HEAD_NEXT_POINTER_MASK;
-               dqh->size_ioc_int_sts = 0;
-
-               /* Ensure that updates to the QH will occur before priming. */
-               wmb();
+       /* Ensure that updates to the QH will occure before priming. */
+       wmb();
 
-               /* Prime the Endpoint */
-               writel(bit_pos, &udc->op_regs->epprime);
+       /* Prime the Endpoint */
+       writel(bit_pos, &udc->op_regs->epprime);
 
-               if (direction == EP_DIR_IN) {
-                       /* FIXME add status check after prime the IN ep */
-                       int prime_again;
-                       u32 curr_dtd_ptr = dqh->curr_dtd_ptr;
-
-                       loops = LOOPS(DTD_TIMEOUT);
-                       prime_again = 0;
-                       while ((curr_dtd_ptr != req->head->td_dma)) {
-                               curr_dtd_ptr = dqh->curr_dtd_ptr;
-                               if (loops == 0) {
-                                       dev_err(&udc->dev->dev,
-                                               "failed to prime %s\n",
-                                               ep->name);
-                                       retval = -ETIME;
-                                       goto done;
-                               }
-                               loops--;
-                               udelay(LOOPS_USEC);
-
-                               if (loops == (LOOPS(DTD_TIMEOUT) >> 2)) {
-                                       if (prime_again)
-                                               goto done;
-                                       dev_info(&udc->dev->dev,
-                                               "prime again\n");
-                                       writel(bit_pos,
-                                               &udc->op_regs->epprime);
-                                       prime_again = 1;
-                               }
-                       }
-               }
-       }
 done:
        return retval;
 }
 
+
 static struct mv_dtd *build_dtd(struct mv_req *req, unsigned *length,
                dma_addr_t *dma, int *is_last)
 {