ARM: OMAP: OMAP2 USB DMA support

-----Original Message-----
From: [email protected] [mailto:linux-omap-open-source- [email protected]] On Behalf Of Kyungmin Park
Sent: Wednesday, October 10, 2007 12:34 PM
To: [email protected]
Subject: [PATCH] ARM: OMAP: OMAP2 USB DMA support

In the previous time, USB DMA has some problem at setup time on OMAP2. I found that the code assumes bulk out required the big data transfer. But MODE SELECT(6) sent the only 24 bytes. it makes a problem. So I implement the small packets handling for it.

Signed-off-by Kyungmin Park <[email protected]>

---

drivers/usb/gadget/omap_udc.c +30 -17

index 74cdce1..3ac4b91 100644
@@ -60,11 +60,6 @@
 /* bulk DMA seems to be behaving for both IN and OUT */
 #define	USE_DMA
 
-/* FIXME: OMAP2 currently has some problem in DMA mode */
-#ifdef CONFIG_ARCH_OMAP2
-#undef USE_DMA
-#endif
-
 /* ISO too */
 #define	USE_ISO
 

@@ -73,6 +68,8 @@
 
 #define	DMA_ADDR_INVALID	(~(dma_addr_t)0)
 
+#define OMAP2_DMA_CH(ch)	(((ch) - 1) << 1)
+#define OMAP24XX_DMA(name, ch)	(OMAP24XX_DMA_##name + OMAP2_DMA_CH(ch))
 
 /*
  * The OMAP UDC needs _very_ early endpoint setup:  before enabling the

@@ -571,20 +568,25 @@ static void next_in_dma(struct omap_ep *ep, struct omap_req *req)
 	const int	sync_mode = cpu_is_omap15xx()
 				? OMAP_DMA_SYNC_FRAME
 				: OMAP_DMA_SYNC_ELEMENT;
+	int		dma_trigger = 0;
+
+	if (cpu_is_omap24xx())
+		dma_trigger = OMAP24XX_DMA(USB_W2FC_TX0, ep->dma_channel);
 
 	/* measure length in either bytes or packets */
 	if ((cpu_is_omap16xx() && length <= UDC_TXN_TSC)
+			|| (cpu_is_omap24xx() && length < ep->maxpacket)
 			|| (cpu_is_omap15xx() && length < ep->maxpacket)) {
 		txdma_ctrl = UDC_TXN_EOT | length;
 		omap_set_dma_transfer_params(ep->lch, OMAP_DMA_DATA_TYPE_S8,
-				length, 1, sync_mode, 0, 0);
+				length, 1, sync_mode, dma_trigger, 0);
 	} else {
 		length = min(length / ep->maxpacket,
 				(unsigned) UDC_TXN_TSC + 1);
 		txdma_ctrl = length;
 		omap_set_dma_transfer_params(ep->lch, OMAP_DMA_DATA_TYPE_S16,
 				ep->ep.maxpacket >> 1, length, sync_mode,
-				0, 0);
+				dma_trigger, 0);
 		length *= ep->maxpacket;
 	}
 	omap_set_dma_src_params(ep->lch, OMAP_DMA_PORT_EMIFF,

@@ -622,20 +624,31 @@ static void finish_in_dma(struct omap_ep *ep, struct omap_req *req, int
 status)
 
 static void next_out_dma(struct omap_ep *ep, struct omap_req *req)
 {
-	unsigned packets;
+	unsigned packets = req->req.length - req->req.actual;
+	int dma_trigger = 0;
+
+	if (cpu_is_omap24xx())
+		dma_trigger = OMAP24XX_DMA(USB_W2FC_RX0, ep->dma_channel);
 
 	/* NOTE:  we filtered out "short reads" before, so we know
 	 * the buffer has only whole numbers of packets.
+	 * except MODE SELECT(6) sent the 24 bytes data in OMAP24XX DMA mode
 	 */
-
-	/* set up this DMA transfer, enable the fifo, start */
-	packets = (req->req.length - req->req.actual) / ep->ep.maxpacket;
-	packets = min(packets, (unsigned)UDC_RXN_TC + 1);
-	req->dma_bytes = packets * ep->ep.maxpacket;
-	omap_set_dma_transfer_params(ep->lch, OMAP_DMA_DATA_TYPE_S16,
-			ep->ep.maxpacket >> 1, packets,
-			OMAP_DMA_SYNC_ELEMENT,
-			0, 0);
+	if (cpu_is_omap24xx() && packets < ep->maxpacket) {
+		omap_set_dma_transfer_params(ep->lch, OMAP_DMA_DATA_TYPE_S8,
+				packets, 1, OMAP_DMA_SYNC_ELEMENT,
+				dma_trigger, 0);
+		req->dma_bytes = packets;
+	} else {
+		/* set up this DMA transfer, enable the fifo, start */
+		packets /= ep->ep.maxpacket;
+		packets = min(packets, (unsigned)UDC_RXN_TC + 1);
+		req->dma_bytes = packets * ep->ep.maxpacket;
+		omap_set_dma_transfer_params(ep->lch, OMAP_DMA_DATA_TYPE_S16,
+				ep->ep.maxpacket >> 1, packets,
+				OMAP_DMA_SYNC_ELEMENT,
+				dma_trigger, 0);
+	}
 	omap_set_dma_dest_params(ep->lch, OMAP_DMA_PORT_EMIFF,
 		OMAP_DMA_AMODE_POST_INC, req->req.dma + req->req.actual,

drivers/usb/gadget/omap_udc.c +18 -6

 		0, 0);

@@ -743,6 +756,7 @@ static void dma_channel_claim(struct omap_ep *ep, unsigned channel)
 {
 	u16	reg;
 	int	status, restart, is_in;
+	int	dma_channel;
 
 	is_in = ep->bEndpointAddress & USB_DIR_IN;
 	if (is_in)

@@ -769,11 +783,15 @@ static void dma_channel_claim(struct omap_ep *ep, unsigned channel)
 	ep->dma_channel = channel;
 
 	if (is_in) {
-		status = omap_request_dma(OMAP_DMA_USB_W2FC_TX0 - 1 + channel,
+		if (cpu_is_omap24xx())
+			dma_channel = OMAP24XX_DMA(USB_W2FC_TX0, channel);
+		else
+			dma_channel = OMAP_DMA_USB_W2FC_TX0 - 1 + channel;
+		status = omap_request_dma(dma_channel,
 			ep->ep.name, dma_error, ep, &ep->lch);
 		if (status == 0) {
 			UDC_TXDMA_CFG_REG = reg;
-			/* EMIFF */
+			/* EMIFF or SDRC */
 			omap_set_dma_src_burst_mode(ep->lch,
 						OMAP_DMA_DATA_BURST_4);
 			omap_set_dma_src_data_pack(ep->lch, 1);

@@ -785,7 +803,12 @@ static void dma_channel_claim(struct omap_ep *ep, unsigned channel)
 				0, 0);
 		}
 	} else {
-		status = omap_request_dma(OMAP_DMA_USB_W2FC_RX0 - 1 + channel,
+		if (cpu_is_omap24xx())
+			dma_channel = OMAP24XX_DMA(USB_W2FC_RX0, channel);
+		else
+			dma_channel = OMAP_DMA_USB_W2FC_RX0 - 1 + channel;
+
+		status = omap_request_dma(dma_channel,
 			ep->ep.name, dma_error, ep, &ep->lch);
 		if (status == 0) {
 			UDC_RXDMA_CFG_REG = reg;

@@ -795,7 +818,7 @@ static void dma_channel_claim(struct omap_ep *ep, unsigned channel)
 				OMAP_DMA_AMODE_CONSTANT,
 				(unsigned long) io_v2p((u32)&UDC_DATA_DMA_REG),
 				0, 0);
-			/* EMIFF */
+			/* EMIFF or SDRC */
 			omap_set_dma_dest_burst_mode(ep->lch,
 						OMAP_DMA_DATA_BURST_4);
 			omap_set_dma_dest_data_pack(ep->lch, 1);

@@ -808,7 +831,7 @@ static void dma_channel_claim(struct omap_ep *ep, unsigned channel)
 		omap_disable_dma_irq(ep->lch, OMAP_DMA_BLOCK_IRQ);
 
 		/* channel type P: hw synch (fifo) */
-		if (!cpu_is_omap15xx())
+		if (cpu_class_is_omap1() && !cpu_is_omap15xx())
 			OMAP1_DMA_LCH_CTRL_REG(ep->lch) = 2;
 	}
 

@@ -926,11 +949,13 @@ omap_ep_queue(struct usb_ep *_ep, struct usb_request *_req, gfp_t gfp_flags)
 
 	/* this isn't bogus, but OMAP DMA isn't the only hardware to
 	 * have a hard time with partial packet reads...  reject it.
+	 * Except OMAP2 can handle the small packets.
 	 */
 	if (use_dma
 			&& ep->has_dma
 			&& ep->bEndpointAddress != 0
 			&& (ep->bEndpointAddress & USB_DIR_IN) == 0
+			&& !cpu_class_is_omap2()
 			&& (req->req.length % ep->ep.maxpacket) != 0) {
 		DBG("%s, no partial packet OUT reads\n", __FUNCTION__);
 		return -EMSGSIZE;

@@ -2555,7 +2580,7 @@ omap_ep_setup(char *name, u8 addr, u8 type,
 		 * (for more reliable behavior)
 		 */
 		if ((!use_dma && (addr & USB_DIR_IN))
-				|| machine_is_omap_apollon()
+				|| (!use_dma && machine_is_omap_apollon())
 				|| cpu_is_omap15xx())
 			dbuf = 0;
 

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Hi David Brownell,

Are there any comments?

Quoted 3 lines · Kyungmin Park

Hi David Brownell,

Are there any comments?

Didn't know I was expected to comment. :)

I didn't test this myself, so I can't comment on those issues. And I don't have time to trace the details of the DMA changes either... it looks plausible though.

Except for this bit at the end:

drivers/usb/gadget/omap_udc.c omap_ep_setup(char *name, u8 addr, u8 type, · line 2585

Quoted 8 lines

drivers/usb/gadget/omap_udc.c +1 -1

@@ -2555,7 +2580,7 @@ omap_ep_setup(char *name, u8 addr, u8 type,
                  * (for more reliable behavior)
                  */
                 if ((!use_dma && (addr & USB_DIR_IN))
-                               || machine_is_omap_apollon()
+                               || (!use_dma && machine_is_omap_apollon())
                                 || cpu_is_omap15xx())
                         dbuf = 0;

Having board-specific logic for that seems clearly wrong. (And I never much liked that original bit either...)

Hi,

Quoted 13 lines · David Brownell

Quoted 3 lines · Kyungmin Park

Hi David Brownell,

Are there any comments?

Didn't know I was expected to comment. :)

I didn't test this myself, so I can't comment on those issues. And I don't have time to trace the details of the DMA changes either... it looks plausible though.

Except for this bit at the end:

Quoted 11 lines

drivers/usb/gadget/omap_udc.c omap_ep_setup(char *name, u8 addr, u8 type, · line 2585

Quoted 8 lines

drivers/usb/gadget/omap_udc.c +1 -1

@@ -2555,7 +2580,7 @@ omap_ep_setup(char *name, u8 addr, u8 type,
                  * (for more reliable behavior)
                  */
                 if ((!use_dma && (addr & USB_DIR_IN))
-                               || machine_is_omap_apollon()
+                               || (!use_dma && machine_is_omap_apollon())
                                 || cpu_is_omap15xx())
                         dbuf = 0;

Having board-specific logic for that seems clearly wrong. (And I never much liked that original bit either...)

Kyungmin, could you please move the dbuf value into platform data and have it set in omap_otg_init() in plat-omap/usb.c so Dave will be happy and we can get your patch integrated into Linus' tree also?