usb: musb: start musb on the udc side, too

commit 001dd84a92a25f8f2bad7d26df8bdb0362302c07 upstream.

I have am335x-evm with one port running in OTG mode. Since commit
fe4cb09 ("usb: musb: gadget: remove hcd initialization") the loaded
gadget does non pop up on the host. All I see is
|usb 4-5: new high-speed USB device number 52 using ehci-pci
|usb 4-5: device descriptor read/64, error -110

Since a later commit 2cc65fe ("usb: musb: add musb_host_setup() and
musb_host_cleanup()) the gadget shows up on the host again but only
in OTG mode (because we have the host init code running). It does not
work in device only mode.
If running in OTG mode and the gadget is removed and added back (rmmod
followed by modprobe of a gadget) then the same error is pops up on the
host side.

This patch ensures that the gadget side also executes musb_start() which
puts the chip in "connect accept" mode. With this change the device
works in OTG & device mode and the gadget can be added & removed
multiple times.
A device (if musb is in OTG mode acting as a host) is only recognized if
it is attached during module load (musb_hdrc module). After the device
unplugged and plugged again the host does not recognize it. We get a
buch of errors if musb running in OTG mode, attached to a host and no
gadget is loaded. Bah.
This is one step forward. Host & device only mode should work. I will
look at OTG later. I looked at this before commit fe4cb09 and OTG wasn't
working there perfectly so I am not sure that it is a regression :)

Cc: Daniel Mack <zonque@gmail.com>
Cc: Peter Korsgaard <jacmet@sunsite.dk>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
index 29a24ced67483d8942f943013ee27a3645902112..6ef8c9407e255210196b0721d98e2f64153e40f3 100644 (file)
--- a/drivers/usb/musb/musb_core.c
+++ b/drivers/usb/musb/musb_core.c
@@ -922,6 +922,52 @@ static void musb_generic_disable(struct musb *musb)
 
 }
 
+/*
+ * Program the HDRC to start (enable interrupts, dma, etc.).
+ */
+void musb_start(struct musb *musb)
+{
+       void __iomem    *regs = musb->mregs;
+       u8              devctl = musb_readb(regs, MUSB_DEVCTL);
+
+       dev_dbg(musb->controller, "<== devctl %02x\n", devctl);
+
+       /*  Set INT enable registers, enable interrupts */
+       musb->intrtxe = musb->epmask;
+       musb_writew(regs, MUSB_INTRTXE, musb->intrtxe);
+       musb->intrrxe = musb->epmask & 0xfffe;
+       musb_writew(regs, MUSB_INTRRXE, musb->intrrxe);
+       musb_writeb(regs, MUSB_INTRUSBE, 0xf7);
+
+       musb_writeb(regs, MUSB_TESTMODE, 0);
+
+       /* put into basic highspeed mode and start session */
+       musb_writeb(regs, MUSB_POWER, MUSB_POWER_ISOUPDATE
+                       | MUSB_POWER_HSENAB
+                       /* ENSUSPEND wedges tusb */
+                       /* | MUSB_POWER_ENSUSPEND */
+                  );
+
+       musb->is_active = 0;
+       devctl = musb_readb(regs, MUSB_DEVCTL);
+       devctl &= ~MUSB_DEVCTL_SESSION;
+
+       /* session started after:
+        * (a) ID-grounded irq, host mode;
+        * (b) vbus present/connect IRQ, peripheral mode;
+        * (c) peripheral initiates, using SRP
+        */
+       if (musb->port_mode != MUSB_PORT_MODE_HOST &&
+                       (devctl & MUSB_DEVCTL_VBUS) == MUSB_DEVCTL_VBUS) {
+               musb->is_active = 1;
+       } else {
+               devctl |= MUSB_DEVCTL_SESSION;
+       }
+
+       musb_platform_enable(musb);
+       musb_writeb(regs, MUSB_DEVCTL, devctl);
+}
+
 /*
  * Make the HDRC stop (disable interrupts, etc.);
  * reversible by musb_start

diff --git a/drivers/usb/musb/musb_core.h b/drivers/usb/musb/musb_core.h
index 7d341c387eab94e4148cba0e8db0e2bf25130811..679dd5b82cc532927ad72dc3fd92186493da1182 100644 (file)
--- a/drivers/usb/musb/musb_core.h
+++ b/drivers/usb/musb/musb_core.h
@@ -511,6 +511,7 @@ static inline void musb_configure_ep0(struct musb *musb)
 extern const char musb_driver_name[];
 
 extern void musb_stop(struct musb *musb);
+extern void musb_start(struct musb *musb);
 
 extern void musb_write_fifo(struct musb_hw_ep *ep, u16 len, const u8 *src);
 extern void musb_read_fifo(struct musb_hw_ep *ep, u16 len, u8 *dst);

diff --git a/drivers/usb/musb/musb_gadget.c b/drivers/usb/musb/musb_gadget.c
index 0414bc19d0095258ab5e646858ce342a740f92c8..d95378a68f6c1a67e1e2bca82340d5c858c3c2e7 100644 (file)
--- a/drivers/usb/musb/musb_gadget.c
+++ b/drivers/usb/musb/musb_gadget.c
@@ -1842,6 +1842,8 @@ static int musb_gadget_start(struct usb_gadget *g,
        musb->xceiv->state = OTG_STATE_B_IDLE;
        spin_unlock_irqrestore(&musb->lock, flags);
 
+       musb_start(musb);
+
        /* REVISIT:  funcall to other code, which also
         * handles power budgeting ... this way also
         * ensures HdrcStart is indirectly called.

diff --git a/drivers/usb/musb/musb_virthub.c b/drivers/usb/musb/musb_virthub.c
index a523950c2b32e66e07f7c8bd78daa181f691f25c..d1d6b83aabca61df43dffccf57ccbe7687cbe399 100644 (file)
--- a/drivers/usb/musb/musb_virthub.c
+++ b/drivers/usb/musb/musb_virthub.c
@@ -44,52 +44,6 @@
 
 #include "musb_core.h"
 
-/*
-* Program the HDRC to start (enable interrupts, dma, etc.).
-*/
-static void musb_start(struct musb *musb)
-{
-       void __iomem    *regs = musb->mregs;
-       u8              devctl = musb_readb(regs, MUSB_DEVCTL);
-
-       dev_dbg(musb->controller, "<== devctl %02x\n", devctl);
-
-       /*  Set INT enable registers, enable interrupts */
-       musb->intrtxe = musb->epmask;
-       musb_writew(regs, MUSB_INTRTXE, musb->intrtxe);
-       musb->intrrxe = musb->epmask & 0xfffe;
-       musb_writew(regs, MUSB_INTRRXE, musb->intrrxe);
-       musb_writeb(regs, MUSB_INTRUSBE, 0xf7);
-
-       musb_writeb(regs, MUSB_TESTMODE, 0);
-
-       /* put into basic highspeed mode and start session */
-       musb_writeb(regs, MUSB_POWER, MUSB_POWER_ISOUPDATE
-                                               | MUSB_POWER_HSENAB
-                                               /* ENSUSPEND wedges tusb */
-                                               /* | MUSB_POWER_ENSUSPEND */
-                                               );
-
-       musb->is_active = 0;
-       devctl = musb_readb(regs, MUSB_DEVCTL);
-       devctl &= ~MUSB_DEVCTL_SESSION;
-
-       /* session started after:
-        * (a) ID-grounded irq, host mode;
-        * (b) vbus present/connect IRQ, peripheral mode;
-        * (c) peripheral initiates, using SRP
-        */
-       if (musb->port_mode != MUSB_PORT_MODE_HOST &&
-           (devctl & MUSB_DEVCTL_VBUS) == MUSB_DEVCTL_VBUS) {
-               musb->is_active = 1;
-       } else {
-               devctl |= MUSB_DEVCTL_SESSION;
-       }
-
-       musb_platform_enable(musb);
-       musb_writeb(regs, MUSB_DEVCTL, devctl);
-}
-
 static void musb_port_suspend(struct musb *musb, bool do_suspend)
 {
        struct usb_otg  *otg = musb->xceiv->otg;