MUSB: Update register access based on new HDRC core spec

Catch up to info from latest HDRC core spec ... some new registers
and fields, and constraints notably

 - not clearing TX fifo unless it's empty (that might explain some
   host side glitching).

 - not all POWER fields are writable
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>

drivers/usb/musb/g_ep0.c

@@ -387,9 +387,10 @@ stall:
 				if (is_in) {
 					csr = musb_readw(regs,
 							MGC_O_HDRC_TXCSR);
+					if (csr & MGC_M_TXCSR_FIFONOTEMPTY)
+						csr |= MGC_M_TXCSR_FLUSHFIFO;
 					csr |= MGC_M_TXCSR_P_SENDSTALL
 						| MGC_M_TXCSR_CLRDATATOG
-						| MGC_M_TXCSR_FLUSHFIFO
 						| MGC_M_TXCSR_P_WZC_BITS;
 					musb_writew(regs, MGC_O_HDRC_TXCSR,
 							csr);

drivers/usb/musb/musb_gadget.c

@@ -297,11 +297,12 @@ static void txstate(struct musb *pThis, struct musb_request *req)
 					pRequest->dma, request_size);
 			if (use_dma) {
 				if (pEnd->dma->bDesiredMode == 0) {
+					/* ASSERT: DMAENAB is clear */
 					wCsrVal &= ~(MGC_M_TXCSR_AUTOSET |
 							MGC_M_TXCSR_DMAMODE);
 					wCsrVal |= (MGC_M_TXCSR_DMAENAB |
 							MGC_M_TXCSR_MODE);
-						// against programming guide
+					// against programming guide
 				}
 				else
 					wCsrVal |= (MGC_M_TXCSR_AUTOSET
@@ -347,6 +348,7 @@ static void txstate(struct musb *pThis, struct musb_request *req)
 		if (!use_dma) {
 			c->channel_release(pEnd->dma);
 			pEnd->dma = NULL;
+			/* ASSERT: DMAENAB clear */
 			wCsrVal &= ~(MGC_M_TXCSR_DMAMODE | MGC_M_TXCSR_MODE);
 			/* invariant: prequest->buf is non-null */
 		}
@@ -837,8 +839,10 @@ done:
 static int musb_gadget_enable(struct usb_ep *ep,
 			const struct usb_endpoint_descriptor *desc)
 {
-	unsigned long flags;
-	struct musb_ep	*pEnd;
+	unsigned long		flags;
+	struct musb_ep		*pEnd;
+	struct musb_hw_ep	*hw_ep;
+	void __iomem		*regs;
 	struct musb	*pThis;
 	void __iomem	*pBase;
 	u8		bEnd;
@@ -850,6 +854,8 @@ static int musb_gadget_enable(struct usb_ep *ep,
 		return -EINVAL;
 
 	pEnd = to_musb_ep(ep);
+	hw_ep = pEnd->hw_ep;
+	regs = hw_ep->regs;
 	pThis = pEnd->pThis;
 	pBase = pThis->pRegs;
 	bEnd = pEnd->bEndNumber;
@@ -879,11 +885,11 @@ static int musb_gadget_enable(struct usb_ep *ep,
 	if (desc->bEndpointAddress & USB_DIR_IN) {
 		u16 wIntrTxE = musb_readw(pBase, MGC_O_HDRC_INTRTXE);
 
-		if (pEnd->hw_ep->bIsSharedFifo)
+		if (hw_ep->bIsSharedFifo)
 			pEnd->is_in = 1;
 		if (!pEnd->is_in)
 			goto fail;
-		if (tmp > pEnd->hw_ep->wMaxPacketSizeTx)
+		if (tmp > hw_ep->wMaxPacketSizeTx)
 			goto fail;
 
 		wIntrTxE |= (1 << bEnd);
@@ -892,25 +898,28 @@ static int musb_gadget_enable(struct usb_ep *ep,
 		/* REVISIT if can_bulk_split(), use by updating "tmp";
 		 * likewise high bandwidth periodic tx
 		 */
-		MGC_WriteCsr16(pBase, MGC_O_HDRC_TXMAXP, bEnd, tmp);
+		musb_writew(regs, MGC_O_HDRC_TXMAXP, tmp);
 
-		csr = MGC_M_TXCSR_MODE | MGC_M_TXCSR_CLRDATATOG
-				| MGC_M_TXCSR_FLUSHFIFO;
+		csr = MGC_M_TXCSR_MODE | MGC_M_TXCSR_CLRDATATOG;
+		if (musb_readw(regs, MGC_O_HDRC_TXCSR)
+				& MGC_M_TXCSR_FIFONOTEMPTY)
+			csr |= MGC_M_TXCSR_FLUSHFIFO;
 		if (pEnd->type == USB_ENDPOINT_XFER_ISOC)
 			csr |= MGC_M_TXCSR_P_ISO;
 
 		/* set twice in case of double buffering */
-		MGC_WriteCsr16(pBase, MGC_O_HDRC_TXCSR, bEnd, csr);
-		MGC_WriteCsr16(pBase, MGC_O_HDRC_TXCSR, bEnd, csr);
+		musb_writew(regs, MGC_O_HDRC_TXCSR, csr);
+		/* REVISIT may be inappropriate w/o FIFONOTEMPTY ... */
+		musb_writew(regs, MGC_O_HDRC_TXCSR, csr);
 
 	} else {
 		u16 wIntrRxE = musb_readw(pBase, MGC_O_HDRC_INTRRXE);
 
-		if (pEnd->hw_ep->bIsSharedFifo)
+		if (hw_ep->bIsSharedFifo)
 			pEnd->is_in = 0;
 		if (pEnd->is_in)
 			goto fail;
-		if (tmp > pEnd->hw_ep->wMaxPacketSizeRx)
+		if (tmp > hw_ep->wMaxPacketSizeRx)
 			goto fail;
 
 		wIntrRxE |= (1 << bEnd);
@@ -922,7 +931,7 @@ static int musb_gadget_enable(struct usb_ep *ep,
 		MGC_WriteCsr16(pBase, MGC_O_HDRC_RXMAXP, bEnd, tmp);
 
 		/* force shared fifo to OUT-only mode */
-		if (pEnd->hw_ep->bIsSharedFifo) {
+		if (hw_ep->bIsSharedFifo) {
 			csr = musb_readw(pBase, MGC_O_HDRC_TXCSR);
 			csr &= ~(MGC_M_TXCSR_MODE | MGC_M_TXCSR_TXPKTRDY);
 			MGC_WriteCsr16(pBase, MGC_O_HDRC_TXCSR, bEnd, csr);
@@ -945,7 +954,7 @@ static int musb_gadget_enable(struct usb_ep *ep,
 	if (is_dma_capable() && pThis->pDmaController) {
 		struct dma_controller	*c = pThis->pDmaController;
 
-		pEnd->dma = c->channel_alloc(c, pEnd->hw_ep,
+		pEnd->dma = c->channel_alloc(c, hw_ep,
 				(desc->bEndpointAddress & USB_DIR_IN));
 	} else
 		pEnd->dma = NULL;
@@ -1292,9 +1301,10 @@ int musb_gadget_set_halt(struct usb_ep *ep, int value)
 	DBG(2, "%s: %s stall\n", ep->name, value ? "set" : "clear");
 	if (pEnd->is_in) {
 		wCsr = MGC_ReadCsr16(pBase, MGC_O_HDRC_TXCSR, bEnd);
+		if (wCsr & MGC_M_TXCSR_FIFONOTEMPTY)
+			wCsr |= MGC_M_TXCSR_FLUSHFIFO;
 		wCsr |= MGC_M_TXCSR_P_WZC_BITS
-			| MGC_M_TXCSR_CLRDATATOG
-			| MGC_M_TXCSR_FLUSHFIFO;
+			| MGC_M_TXCSR_CLRDATATOG;
 		if (value)
 			wCsr |= MGC_M_TXCSR_P_SENDSTALL;
 		else
@@ -1371,9 +1381,12 @@ static void musb_gadget_fifo_flush(struct usb_ep *ep)
 
 	if (musb_ep->is_in) {
 		wCsr = MGC_ReadCsr16(mbase, MGC_O_HDRC_TXCSR, nEnd);
-		wCsr |= MGC_M_TXCSR_FLUSHFIFO | MGC_M_TXCSR_P_WZC_BITS;
-		MGC_WriteCsr16(mbase, MGC_O_HDRC_TXCSR, nEnd, wCsr);
-		MGC_WriteCsr16(mbase, MGC_O_HDRC_TXCSR, nEnd, wCsr);
+		if (wCsr & MGC_M_TXCSR_FIFONOTEMPTY) {
+			wCsr |= MGC_M_TXCSR_FLUSHFIFO | MGC_M_TXCSR_P_WZC_BITS;
+			MGC_WriteCsr16(mbase, MGC_O_HDRC_TXCSR, nEnd, wCsr);
+			/* REVISIT may be inappropriate w/o FIFONOTEMPTY ... */
+			MGC_WriteCsr16(mbase, MGC_O_HDRC_TXCSR, nEnd, wCsr);
+		}
 	} else {
 		wCsr = MGC_ReadCsr16(mbase, MGC_O_HDRC_RXCSR, nEnd);
 		wCsr |= MGC_M_RXCSR_FLUSHFIFO | MGC_M_RXCSR_P_WZC_BITS;
@@ -1413,17 +1426,21 @@ static int musb_gadget_wakeup(struct usb_gadget *gadget)
 {
 	struct musb	*musb = gadget_to_musb(gadget);
 	unsigned long	flags;
-	int		status = 0;
+	int		status = -EINVAL;
 	u8		power;
 
 	spin_lock_irqsave(&musb->Lock, flags);
 
+	/* fail if we're not suspended */
+	power = musb_readb(musb->pRegs, MGC_O_HDRC_POWER);
+	if (!(power & MGC_M_POWER_SUSPENDM))
+		goto done;
+
 	switch (musb->xceiv.state) {
 	case OTG_STATE_B_PERIPHERAL:
-		/* FIXME if not suspended, fail */
 		if (musb->bMayWakeup)
 			break;
-		goto fail;
+		goto done;
 	case OTG_STATE_B_IDLE:
 		/* REVISIT we might be able to do SRP even without OTG,
 		 * though Linux doesn't yet expose that capability
@@ -1434,12 +1451,10 @@ static int musb_gadget_wakeup(struct usb_gadget *gadget)
 		}
 		/* FALLTHROUGH */
 	default:
-fail:
-		status = -EINVAL;
 		goto done;
 	}
 
-	power = musb_readb(musb->pRegs, MGC_O_HDRC_POWER);
+	status = 0;
 	power |= MGC_M_POWER_RESUME;
 	musb_writeb(musb->pRegs, MGC_O_HDRC_POWER, power);
 

drivers/usb/musb/musb_host.c

@@ -717,7 +717,11 @@ static void musb_ep_program(struct musb *pThis, u8 bEnd,
 		if (bEnd) {
 			u16	csr = wCsr;
 
+			/* ASSERT:  TXCSR_DMAENAB was already cleared */
+
 			/* flush all old state, set default */
+			if (csr & MGC_M_TXCSR_FIFONOTEMPTY)
+				csr |= MGC_M_TXCSR_FLUSHFIFO;
 			csr &= ~(MGC_M_TXCSR_H_NAKTIMEOUT
 					| MGC_M_TXCSR_DMAMODE
 					| MGC_M_TXCSR_FRCDATATOG
@@ -727,8 +731,7 @@ static void musb_ep_program(struct musb *pThis, u8 bEnd,
 					| MGC_M_TXCSR_FIFONOTEMPTY
 					| MGC_M_TXCSR_TXPKTRDY
 					);
-			csr |= MGC_M_TXCSR_FLUSHFIFO
-					| MGC_M_TXCSR_MODE;
+			csr |= MGC_M_TXCSR_MODE;
 
 			if (qh->type == USB_ENDPOINT_XFER_ISOC)
 				csr |= MGC_M_TXCSR_ISO;
@@ -742,6 +745,7 @@ static void musb_ep_program(struct musb *pThis, u8 bEnd,
 			/* twice in case of double packet buffering */
 			MGC_WriteCsr16(pBase, MGC_O_HDRC_TXCSR, bEnd,
 					csr);
+			/* REVISIT may need to clear FLUSHFIFO ... */
 			MGC_WriteCsr16(pBase, MGC_O_HDRC_TXCSR, bEnd,
 					csr);
 			wCsr = MGC_ReadCsr16(pBase, MGC_O_HDRC_TXCSR,
@@ -765,6 +769,7 @@ static void musb_ep_program(struct musb *pThis, u8 bEnd,
 			musb_writeb(pBase,
 				MGC_BUSCTL_OFFSET(bEnd, MGC_O_HDRC_TXHUBPORT),
 				qh->h_port_reg);
+/* FIXME if !bEnd, do the same for RX ... */
 		} else
 			musb_writeb(pBase, MGC_O_HDRC_FADDR, qh->addr_reg);
 
@@ -884,6 +889,8 @@ static void musb_ep_program(struct musb *pThis, u8 bEnd,
 		}
 #endif
 		if (wLoadCount) {
+			/* ASSERT:  TXCSR_DMAENAB was already cleared */
+
 			/* PIO to load FIFO */
 			qh->segsize = wLoadCount;
 			musb_write_fifo(pEnd, wLoadCount, pBuffer);
@@ -1223,13 +1230,15 @@ void musb_host_tx(struct musb *pThis, u8 bEnd)
 
 	/* check for errors */
 	if (wTxCsrVal & MGC_M_TXCSR_H_RXSTALL) {
+		/* dma was disabled, fifo flushed */
 		DBG(3, "TX end %d stall\n", bEnd);
 
 		/* stall; record URB status */
 		status = -EPIPE;
 
 	} else if (wTxCsrVal & MGC_M_TXCSR_H_ERROR) {
-		DBG(3, "TX data error on ep=%d\n", bEnd);
+		/* (NON-ISO) dma was disabled, fifo flushed */
+		DBG(3, "TX 3strikes on ep=%d\n", bEnd);
 
 		status = -ETIMEDOUT;
 
@@ -1260,6 +1269,8 @@ void musb_host_tx(struct musb *pThis, u8 bEnd)
 		 * usb core; the dma engine should already be stopped.
 		 */
 // SCRUB (TX)
+		if (wTxCsrVal & MGC_M_TXCSR_FIFONOTEMPTY)
+			wTxCsrVal |= MGC_M_TXCSR_FLUSHFIFO;
 		wTxCsrVal &= ~(MGC_M_TXCSR_FIFONOTEMPTY
 				| MGC_M_TXCSR_AUTOSET
 				| MGC_M_TXCSR_DMAENAB
@@ -1267,10 +1278,10 @@ void musb_host_tx(struct musb *pThis, u8 bEnd)
 				| MGC_M_TXCSR_H_RXSTALL
 				| MGC_M_TXCSR_H_NAKTIMEOUT
 				);
-		wTxCsrVal |= MGC_M_TXCSR_FLUSHFIFO;
 
 		MGC_SelectEnd(pBase, bEnd);
 		MGC_WriteCsr16(pBase, MGC_O_HDRC_TXCSR, bEnd, wTxCsrVal);
+		/* REVISIT may need to clear FLUSHFIFO ... */
 		MGC_WriteCsr16(pBase, MGC_O_HDRC_TXCSR, bEnd, wTxCsrVal);
 		MGC_WriteCsr8(pBase, MGC_O_HDRC_TXINTERVAL, bEnd, 0);
 
@@ -1977,6 +1988,8 @@ static int musb_cleanup_urb(struct urb *urb, struct musb_qh *qh, int is_in)
 	} else {
 // SCRUB (TX)
 		csr = MGC_ReadCsr16(regs, MGC_O_HDRC_TXCSR, hw_end);
+		if (csr & MGC_M_TXCSR_FIFONOTEMPTY)
+			csr |= MGC_M_TXCSR_FLUSHFIFO;
 		csr &= ~( MGC_M_TXCSR_AUTOSET
 			| MGC_M_TXCSR_DMAENAB
 			| MGC_M_TXCSR_H_RXSTALL
@@ -1984,8 +1997,8 @@ static int musb_cleanup_urb(struct urb *urb, struct musb_qh *qh, int is_in)
 			| MGC_M_TXCSR_H_ERROR
 			| MGC_M_TXCSR_FIFONOTEMPTY
 			);
-		csr |= MGC_M_TXCSR_FLUSHFIFO;
 		MGC_WriteCsr16(regs, MGC_O_HDRC_TXCSR, 0, csr);
+		/* REVISIT may need to clear FLUSHFIFO ... */
 		MGC_WriteCsr16(regs, MGC_O_HDRC_TXCSR, 0, csr);
 		/* flush cpu writebuffer */
 		csr = MGC_ReadCsr16(regs, MGC_O_HDRC_TXCSR, hw_end);

drivers/usb/musb/musbhdrc.h

@@ -71,8 +71,6 @@
 /* Additional Control Registers */
 
 #define MGC_O_HDRC_DEVCTL	0x60	/* 8 bit */
-// vctrl/vstatus:  optional vendor utmi+phy register at 0x68
-#define MGC_O_HDRC_HWVERS	0x6C	/* 8 bit */
 
 /* These are always controlled through the INDEX register */
 #define MGC_O_HDRC_TXFIFOSZ	0x62	/* 8-bit (see masks) */
@@ -80,6 +78,17 @@
 #define MGC_O_HDRC_TXFIFOADD	0x64	/* 16-bit offset shifted right 3 */
 #define MGC_O_HDRC_RXFIFOADD	0x66	/* 16-bit offset shifted right 3 */
 
+// vctrl/vstatus:  optional vendor utmi+phy register at 0x68
+#define MGC_O_HDRC_HWVERS	0x6C	/* 8 bit */
+
+#define MGC_O_HDRC_EPINFO	0x78	/* 8 bit */
+#define MGC_O_HDRC_RAMINFO	0x79	/* 8 bit */
+#define MGC_O_HDRC_LINKINFO	0x7a	/* 8 bit */
+#define MGC_O_HDRC_VPLEN	0x7b	/* 8 bit */
+#define MGC_O_HDRC_HS_EOF1	0x7c	/* 8 bit */
+#define MGC_O_HDRC_FS_EOF1	0x7d	/* 8 bit */
+#define MGC_O_HDRC_LS_EOF1	0x7e	/* 8 bit */
+
 /* offsets to endpoint registers */
 #define MGC_O_HDRC_TXMAXP	0x00
 #define MGC_O_HDRC_TXCSR	0x02
@@ -112,7 +121,7 @@
 #include "tusb6010.h"		/* needed "only" for TUSB_EP0_CONF */
 #endif
 
-/* "bus control" registers */
+/* "bus control"/target registers, for host side multipoint (external hubs) */
 #define MGC_O_HDRC_TXFUNCADDR	0x00
 #define MGC_O_HDRC_TXHUBADDR	0x02
 #define MGC_O_HDRC_TXHUBPORT	0x03
@@ -149,7 +158,6 @@
 #define MGC_M_INTR_DISCONNECT 0x20
 #define MGC_M_INTR_SESSREQ    0x40
 #define MGC_M_INTR_VBUSERROR  0x80	/* FOR SESSION END */
-#define MGC_M_INTR_EP0      0x01	/* FOR EP0 INTERRUPT */
 
 /* DEVCTL */
 #define MGC_M_DEVCTL_BDEVICE    0x80
@@ -191,6 +199,7 @@
 #define MGC_M_CSR0_P_SENTSTALL    0x0004
 
 /* CSR0 in Host mode */
+#define MGC_M_CSR0_H_DIS_PING	0x0800
 #define MGC_M_CSR0_H_WR_DATATOGGLE   0x0400	/* set to allow setting: */
 #define MGC_M_CSR0_H_DATATOGGLE	    0x0200	/* data toggle control */
 #define MGC_M_CSR0_H_NAKTIMEOUT   0x0080
@@ -214,9 +223,9 @@
 #define MGC_TYPE_SPEED_HIGH	1
 #define MGC_TYPE_SPEED_FULL	2
 #define MGC_TYPE_SPEED_LOW	3
-#define MGC_M_TYPE_PROTO	0x30
+#define MGC_M_TYPE_PROTO	0x30	/* implicitly zero for ep0 */
 #define MGC_S_TYPE_PROTO	4
-#define MGC_M_TYPE_REMOTE_END	0xf
+#define MGC_M_TYPE_REMOTE_END	0xf	/* implicitly zero for ep0 */
 
 /* CONFIGDATA */
 
@@ -271,6 +280,7 @@
 #define MGC_M_RXCSR_AUTOCLEAR     0x8000
 #define MGC_M_RXCSR_DMAENAB       0x2000
 #define MGC_M_RXCSR_DISNYET       0x1000
+#define MGC_M_RXCSR_PID_ERR       0x1000
 #define MGC_M_RXCSR_DMAMODE       0x0800
 #define MGC_M_RXCSR_INCOMPRX      0x0100
 #define MGC_M_RXCSR_CLRDATATOG    0x0080

drivers/usb/musb/plat_uds.c

@@ -387,7 +387,10 @@ static irqreturn_t musb_stage0_irq(struct musb * pThis, u8 bIntrUSB,
 
 		if (devctl & MGC_M_DEVCTL_HM) {
 #ifdef CONFIG_USB_MUSB_HDRC_HCD
-			/* REVISIT:  this is where SRP kicks in, yes? */
+			/* REVISIT:  this is where SRP kicks in, yes?
+			 * host responsibility should be to CLEAR the
+			 * resume signaling after 50 msec ...
+			 */
 			MUSB_HST_MODE(pThis);	/* unnecessary */
 			power &= ~MGC_M_POWER_SUSPENDM;
 			musb_writeb(pBase, MGC_O_HDRC_POWER,

drivers/usb/musb/virthub.c

@@ -60,7 +60,6 @@ static void musb_port_suspend(struct musb *musb, u8 bSuspend)
 		musb->port1_status |= USB_PORT_STAT_SUSPEND;
 	} else if (power & MGC_M_POWER_SUSPENDM) {
 		DBG(3, "Root port resumed\n");
-		power &= ~(MGC_M_POWER_SUSPENDM | MGC_M_POWER_RESUME);
 		musb_writeb(pBase, MGC_O_HDRC_POWER,
 				power | MGC_M_POWER_RESUME);