usb: mtu3: handle delayed status of the control transfer

Add the delayed status handling. This is used by mass storage etc to
gain some extra time to setup its internal status before it can proceed
further requests, and once the gadget is ready, it will enqueue an
empty packet which is used for synchronization.
The issue may happen on some FGPA platform with very low cpu frequency.

Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/mtu3/mtu3.h b/drivers/usb/mtu3/mtu3.h
index 7b6dc23d77e9af22bc373f28ba1c1313e4eb1faa..b26fffc58446d5d77f49af755cf5faf2a225c26f 100644 (file)
--- a/drivers/usb/mtu3/mtu3.h
+++ b/drivers/usb/mtu3/mtu3.h
@@ -288,6 +288,7 @@ static inline struct ssusb_mtk *dev_to_ssusb(struct device *dev)
  *             MTU3_U3_IP_SLOT_DEFAULT for U3 IP
  * @may_wakeup: means device's remote wakeup is enabled
  * @is_self_powered: is reported in device status and the config descriptor
+ * @delayed_status: true when function drivers ask for delayed status
  * @ep0_req: dummy request used while handling standard USB requests
  *             for GET_STATUS and SET_SEL
  * @setup_buf: ep0 response buffer for GET_STATUS and SET_SEL requests
@@ -327,6 +328,7 @@ struct mtu3 {
        unsigned u1_enable:1;
        unsigned u2_enable:1;
        unsigned is_u3_ip:1;
+       unsigned delayed_status:1;
 
        u8 address;
        u8 test_mode_nr;

diff --git a/drivers/usb/mtu3/mtu3_gadget.c b/drivers/usb/mtu3/mtu3_gadget.c
index 9dd2441b4fa1a2f82d605522f4f8415574fe0cab..a4ad67cf0c52c11fc96a3529af1d5fb402d447bc 100644 (file)
--- a/drivers/usb/mtu3/mtu3_gadget.c
+++ b/drivers/usb/mtu3/mtu3_gadget.c
@@ -663,6 +663,7 @@ int mtu3_gadget_setup(struct mtu3 *mtu)
        mtu->g.sg_supported = 0;
        mtu->g.name = MTU3_DRIVER_NAME;
        mtu->is_active = 0;
+       mtu->delayed_status = false;
 
        mtu3_gadget_init_eps(mtu);
 
@@ -727,4 +728,5 @@ void mtu3_gadget_reset(struct mtu3 *mtu)
        mtu->address = 0;
        mtu->ep0_state = MU3D_EP0_STATE_SETUP;
        mtu->may_wakeup = 0;
+       mtu->delayed_status = false;
 }

diff --git a/drivers/usb/mtu3/mtu3_gadget_ep0.c b/drivers/usb/mtu3/mtu3_gadget_ep0.c
index 2d7427b48775663a68f2f12226112db10f6c29a4..958d74dd2b789593f06c7744def111b76a38424d 100644 (file)
--- a/drivers/usb/mtu3/mtu3_gadget_ep0.c
+++ b/drivers/usb/mtu3/mtu3_gadget_ep0.c
@@ -16,6 +16,8 @@
  *
  */
 
+#include <linux/usb/composite.h>
+
 #include "mtu3.h"
 
 /* ep0 is always mtu3->in_eps[0] */
@@ -150,6 +152,7 @@ static void ep0_stall_set(struct mtu3_ep *mep0, bool set, u32 pktrdy)
                csr = (csr & ~EP0_SENDSTALL) | EP0_SENTSTALL;
        mtu3_writel(mtu->mac_base, U3D_EP0CSR, csr);
 
+       mtu->delayed_status = false;
        mtu->ep0_state = MU3D_EP0_STATE_SETUP;
 
        dev_dbg(mtu->dev, "ep0: %s STALL, ep0_state: %s\n",
@@ -656,6 +659,9 @@ stall:
 finish:
        if (mtu->test_mode) {
                ;       /* nothing to do */
+       } else if (handled == USB_GADGET_DELAYED_STATUS) {
+               /* handle the delay STATUS phase till receive ep_queue on ep0 */
+               mtu->delayed_status = true;
        } else if (le16_to_cpu(setup.wLength) == 0) { /* no data stage */
 
                mtu3_writel(mbase, U3D_EP0CSR,
@@ -775,9 +781,6 @@ static int ep0_queue(struct mtu3_ep *mep, struct mtu3_request *mreq)
        dev_dbg(mtu->dev, "%s %s (ep0_state: %s), len#%d\n", __func__,
                mep->name, decode_ep0_state(mtu), mreq->request.length);
 
-       if (!list_empty(&mep->req_list))
-               return -EBUSY;
-
        switch (mtu->ep0_state) {
        case MU3D_EP0_STATE_SETUP:
        case MU3D_EP0_STATE_RX: /* control-OUT data */
@@ -789,6 +792,20 @@ static int ep0_queue(struct mtu3_ep *mep, struct mtu3_request *mreq)
                return -EINVAL;
        }
 
+       if (mtu->delayed_status) {
+               u32 csr;
+
+               mtu->delayed_status = false;
+               csr = mtu3_readl(mtu->mac_base, U3D_EP0CSR) & EP0_W1C_BITS;
+               csr |= EP0_SETUPPKTRDY | EP0_DATAEND;
+               mtu3_writel(mtu->mac_base, U3D_EP0CSR, csr);
+               /* needn't giveback the request for handling delay STATUS */
+               return 0;
+       }
+
+       if (!list_empty(&mep->req_list))
+               return -EBUSY;
+
        list_add_tail(&mreq->list, &mep->req_list);
 
        /* sequence #1, IN ... start writing the data */