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>

1 files changed, 38 insertions, 101 deletions

diff --git a/drivers/usb/gadget/mv_udc_core.c b/drivers/usb/gadget/mv_udc_core.c
index 635ee47dd4e..0ad321d94f2 100644
--- 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)
 {