usb: gadget: s3c-hsotg: add multi count support

This patch adds Multi Count support. It adds few modifications:
- Fix s3c_hsotg_set_ep_maxpacket() function. Field wMaxPacketSize of endpoint
  descriptor is now splitted into maximum packet size value and number of
  additional transaction per microframe.
- Modify s3c_hsotg_write_fifo() function. It actually calculates transfer
  size, taking into account Multi Count value, which indicates number of
  transactions per microframe.
- Fix s3c_hsotg_start_req() function by setting number of packets to Multi
  Count field in DIEPTSIZ register for isochronous endpoints.

Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

diff --git a/drivers/usb/gadget/s3c-hsotg.c b/drivers/usb/gadget/s3c-hsotg.c
index 961abcd..920e3c9 100644 (file)
--- a/drivers/usb/gadget/s3c-hsotg.c
+++ b/drivers/usb/gadget/s3c-hsotg.c
@@ -83,6 +83,7 @@ struct s3c_hsotg_req;
  * @dir_in: Set to true if this endpoint is of the IN direction, which
  *         means that it is sending data to the Host.
  * @index: The index for the endpoint registers.
+ * @mc: Multi Count - number of transactions per microframe
  * @interval - Interval for periodic endpoints
  * @name: The name array passed to the USB core.
  * @halted: Set if the endpoint has been halted.
@@ -123,6 +124,7 @@ struct s3c_hsotg_ep {
 
        unsigned char           dir_in;
        unsigned char           index;
+       unsigned char           mc;
        unsigned char           interval;
 
        unsigned int            halted:1;
@@ -472,6 +474,7 @@ static int s3c_hsotg_write_fifo(struct s3c_hsotg *hsotg,
        void *data;
        int can_write;
        int pkt_round;
+       int max_transfer;
 
        to_write -= (buf_pos - hs_ep->last_load);
 
@@ -539,8 +542,10 @@ static int s3c_hsotg_write_fifo(struct s3c_hsotg *hsotg,
                can_write *= 4; /* fifo size is in 32bit quantities. */
        }
 
-       dev_dbg(hsotg->dev, "%s: GNPTXSTS=%08x, can=%d, to=%d, mps %d\n",
-                __func__, gnptxsts, can_write, to_write, hs_ep->ep.maxpacket);
+       max_transfer = hs_ep->ep.maxpacket * hs_ep->mc;
+
+       dev_dbg(hsotg->dev, "%s: GNPTXSTS=%08x, can=%d, to=%d, max_transfer %d\n",
+                __func__, gnptxsts, can_write, to_write, max_transfer);
 
        /*
         * limit to 512 bytes of data, it seems at least on the non-periodic
@@ -555,8 +560,8 @@ static int s3c_hsotg_write_fifo(struct s3c_hsotg *hsotg,
         * the transfer to return that it did not run out of fifo space
         * doing it.
         */
-       if (to_write > hs_ep->ep.maxpacket) {
-               to_write = hs_ep->ep.maxpacket;
+       if (to_write > max_transfer) {
+               to_write = max_transfer;
 
                s3c_hsotg_en_gsint(hsotg,
                                   periodic ? GINTSTS_PTxFEmp :
@@ -567,7 +572,7 @@ static int s3c_hsotg_write_fifo(struct s3c_hsotg *hsotg,
 
        if (to_write > can_write) {
                to_write = can_write;
-               pkt_round = to_write % hs_ep->ep.maxpacket;
+               pkt_round = to_write % max_transfer;
 
                /*
                 * Round the write down to an
@@ -731,8 +736,16 @@ static void s3c_hsotg_start_req(struct s3c_hsotg *hsotg,
        else
                packets = 1;    /* send one packet if length is zero. */
 
+       if (hs_ep->isochronous && length > (hs_ep->mc * hs_ep->ep.maxpacket)) {
+               dev_err(hsotg->dev, "req length > maxpacket*mc\n");
+               return;
+       }
+
        if (dir_in && index != 0)
-               epsize = DxEPTSIZ_MC(1);
+               if (hs_ep->isochronous)
+                       epsize = DxEPTSIZ_MC(packets);
+               else
+                       epsize = DxEPTSIZ_MC(1);
        else
                epsize = 0;
 
@@ -1702,6 +1715,7 @@ static void s3c_hsotg_set_ep_maxpacket(struct s3c_hsotg *hsotg,
        struct s3c_hsotg_ep *hs_ep = &hsotg->eps[ep];
        void __iomem *regs = hsotg->regs;
        u32 mpsval;
+       u32 mcval;
        u32 reg;
 
        if (ep == 0) {
@@ -1710,10 +1724,15 @@ static void s3c_hsotg_set_ep_maxpacket(struct s3c_hsotg *hsotg,
                if (mpsval > 3)
                        goto bad_mps;
                hs_ep->ep.maxpacket = mps;
+               hs_ep->mc = 1;
        } else {
                mpsval = mps & DxEPCTL_MPS_MASK;
                if (mpsval > 1024)
                        goto bad_mps;
+               mcval = ((mps >> 11) & 0x3) + 1;
+               hs_ep->mc = mcval;
+               if (mcval > 3)
+                       goto bad_mps;
                hs_ep->ep.maxpacket = mpsval;
        }
 
@@ -2599,6 +2618,9 @@ static int s3c_hsotg_ep_enable(struct usb_ep *ep,
        hs_ep->periodic = 0;
        hs_ep->interval = desc->bInterval;
 
+       if (hs_ep->interval > 1 && hs_ep->mc > 1)
+               dev_err(hsotg->dev, "MC > 1 when interval is not 1\n");
+
        switch (desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) {
        case USB_ENDPOINT_XFER_ISOC:
                epctrl |= DxEPCTL_EPType_Iso;