usb: mtu3: add tracepoints to help debug

This patch implements a few initial tracepoints for the
mtu3 driver. More traces can be added as necessary in order
to ease the task of debugging.

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

drivers/usb/mtu3/Makefile

@@ -2,10 +2,17 @@
 
 ccflags-$(CONFIG_USB_MTU3_DEBUG)	+= -DDEBUG
 
+# define_trace.h needs to know how to find our header
+CFLAGS_mtu3_trace.o	:= -I$(src)
+
 obj-$(CONFIG_USB_MTU3)	+= mtu3.o
 
 mtu3-y	:= mtu3_plat.o
 
+ifneq ($(CONFIG_TRACING),)
+	mtu3-y	+= mtu3_trace.o
+endif
+
 ifneq ($(filter y,$(CONFIG_USB_MTU3_HOST) $(CONFIG_USB_MTU3_DUAL_ROLE)),)
 	mtu3-y	+= mtu3_host.o
 endif

drivers/usb/mtu3/mtu3_core.c

@@ -17,6 +17,7 @@
 
 #include "mtu3.h"
 #include "mtu3_debug.h"
+#include "mtu3_trace.h"
 
 static int ep_fifo_alloc(struct mtu3_ep *mep, u32 seg_size)
 {
@@ -656,6 +657,8 @@ static irqreturn_t mtu3_link_isr(struct mtu3 *mtu)
 		break;
 	}
 	dev_dbg(mtu->dev, "%s: %s\n", __func__, usb_speed_string(udev_speed));
+	mtu3_dbg_trace(mtu->dev, "link speed %s",
+		       usb_speed_string(udev_speed));
 
 	mtu->g.speed = udev_speed;
 	mtu->g.ep0->maxpacket = maxpkt;
@@ -678,6 +681,7 @@ static irqreturn_t mtu3_u3_ltssm_isr(struct mtu3 *mtu)
 	ltssm &= mtu3_readl(mbase, U3D_LTSSM_INTR_ENABLE);
 	mtu3_writel(mbase, U3D_LTSSM_INTR, ltssm); /* W1C */
 	dev_dbg(mtu->dev, "=== LTSSM[%x] ===\n", ltssm);
+	trace_mtu3_u3_ltssm_isr(ltssm);
 
 	if (ltssm & (HOT_RST_INTR | WARM_RST_INTR))
 		mtu3_gadget_reset(mtu);
@@ -708,6 +712,7 @@ static irqreturn_t mtu3_u2_common_isr(struct mtu3 *mtu)
 	u2comm &= mtu3_readl(mbase, U3D_COMMON_USB_INTR_ENABLE);
 	mtu3_writel(mbase, U3D_COMMON_USB_INTR, u2comm); /* W1C */
 	dev_dbg(mtu->dev, "=== U2COMM[%x] ===\n", u2comm);
+	trace_mtu3_u2_common_isr(u2comm);
 
 	if (u2comm & SUSPEND_INTR)
 		mtu3_gadget_suspend(mtu);

drivers/usb/mtu3/mtu3_debug.h

@@ -39,4 +39,12 @@ static inline void ssusb_debugfs_remove_root(struct ssusb_mtk *ssusb) {}
 
 #endif /* CONFIG_DEBUG_FS */
 
+#if IS_ENABLED(CONFIG_TRACING)
+void mtu3_dbg_trace(struct device *dev, const char *fmt, ...);
+
+#else
+static inline void mtu3_dbg_trace(struct device *dev, const char *fmt, ...) {}
+
+#endif /* CONFIG_TRACING */
+
 #endif /* __MTU3_DEBUG_H__ */

drivers/usb/mtu3/mtu3_dr.c

@@ -141,6 +141,7 @@ static void ssusb_set_mailbox(struct otg_switch_mtk *otg_sx,
 	struct mtu3 *mtu = ssusb->u3d;
 
 	dev_dbg(ssusb->dev, "mailbox state(%d)\n", status);
+	mtu3_dbg_trace(ssusb->dev, "mailbox %d", status);
 
 	switch (status) {
 	case MTU3_ID_GROUND:

drivers/usb/mtu3/mtu3_gadget.c

@@ -8,6 +8,7 @@
  */
 
 #include "mtu3.h"
+#include "mtu3_trace.h"
 
 void mtu3_req_complete(struct mtu3_ep *mep,
 		     struct usb_request *req, int status)
@@ -25,6 +26,8 @@ __acquires(mep->mtu->lock)
 
 	mtu = mreq->mtu;
 	mep->busy = 1;
+
+	trace_mtu3_req_complete(mreq);
 	spin_unlock(&mtu->lock);
 
 	/* ep0 makes use of PIO, needn't unmap it */
@@ -201,6 +204,7 @@ static int mtu3_gadget_ep_enable(struct usb_ep *ep,
 	spin_unlock_irqrestore(&mtu->lock, flags);
 
 	dev_dbg(mtu->dev, "%s active_ep=%d\n", __func__, mtu->active_ep);
+	trace_mtu3_gadget_ep_enable(mep);
 
 	return ret;
 }
@@ -212,6 +216,7 @@ static int mtu3_gadget_ep_disable(struct usb_ep *ep)
 	unsigned long flags;
 
 	dev_dbg(mtu->dev, "%s %s\n", __func__, mep->name);
+	trace_mtu3_gadget_ep_disable(mep);
 
 	if (!(mep->flags & MTU3_EP_ENABLED)) {
 		dev_warn(mtu->dev, "%s is already disabled\n", mep->name);
@@ -242,13 +247,17 @@ struct usb_request *mtu3_alloc_request(struct usb_ep *ep, gfp_t gfp_flags)
 	mreq->request.dma = DMA_ADDR_INVALID;
 	mreq->epnum = mep->epnum;
 	mreq->mep = mep;
+	trace_mtu3_alloc_request(mreq);
 
 	return &mreq->request;
 }
 
 void mtu3_free_request(struct usb_ep *ep, struct usb_request *req)
 {
-	kfree(to_mtu3_request(req));
+	struct mtu3_request *mreq = to_mtu3_request(req);
+
+	trace_mtu3_free_request(mreq);
+	kfree(mreq);
 }
 
 static int mtu3_gadget_queue(struct usb_ep *ep,
@@ -316,6 +325,7 @@ static int mtu3_gadget_queue(struct usb_ep *ep,
 
 error:
 	spin_unlock_irqrestore(&mtu->lock, flags);
+	trace_mtu3_gadget_queue(mreq);
 
 	return ret;
 }
@@ -333,6 +343,7 @@ static int mtu3_gadget_dequeue(struct usb_ep *ep, struct usb_request *req)
 		return -EINVAL;
 
 	dev_dbg(mtu->dev, "%s : req=%p\n", __func__, req);
+	trace_mtu3_gadget_dequeue(mreq);
 
 	spin_lock_irqsave(&mtu->lock, flags);
 
@@ -403,6 +414,7 @@ static int mtu3_gadget_ep_set_halt(struct usb_ep *ep, int value)
 
 done:
 	spin_unlock_irqrestore(&mtu->lock, flags);
+	trace_mtu3_gadget_ep_set_halt(mep);
 
 	return ret;
 }

drivers/usb/mtu3/mtu3_gadget_ep0.c

@@ -11,6 +11,8 @@
 #include <linux/usb/composite.h>
 
 #include "mtu3.h"
+#include "mtu3_debug.h"
+#include "mtu3_trace.h"
 
 /* ep0 is always mtu3->in_eps[0] */
 #define	next_ep0_request(mtu)	next_request((mtu)->ep0)
@@ -634,6 +636,7 @@ __acquires(mtu->lock)
 	int handled = 0;
 
 	ep0_read_setup(mtu, &setup);
+	trace_mtu3_handle_setup(&setup);
 
 	if ((setup.bRequestType & USB_TYPE_MASK) == USB_TYPE_STANDARD)
 		handled = handle_standard_request(mtu, &setup);
@@ -710,6 +713,7 @@ irqreturn_t mtu3_ep0_isr(struct mtu3 *mtu)
 		ret = IRQ_HANDLED;
 	}
 	dev_dbg(mtu->dev, "ep0_state: %s\n", decode_ep0_state(mtu));
+	mtu3_dbg_trace(mtu->dev, "ep0_state %s", decode_ep0_state(mtu));
 
 	switch (mtu->ep0_state) {
 	case MU3D_EP0_STATE_TX:

drivers/usb/mtu3/mtu3_qmu.c

@@ -22,6 +22,7 @@
 #include <linux/iopoll.h>
 
 #include "mtu3.h"
+#include "mtu3_trace.h"
 
 #define QMU_CHECKSUM_LEN	16
 
@@ -275,6 +276,7 @@ static int mtu3_prepare_tx_gpd(struct mtu3_ep *mep, struct mtu3_request *mreq)
 	gpd->dw0_info |= cpu_to_le32(GPD_FLAGS_IOC | GPD_FLAGS_HWO);
 
 	mreq->gpd = gpd;
+	trace_mtu3_prepare_gpd(mep, gpd);
 
 	return 0;
 }
@@ -307,6 +309,7 @@ static int mtu3_prepare_rx_gpd(struct mtu3_ep *mep, struct mtu3_request *mreq)
 	gpd->dw0_info |= cpu_to_le32(GPD_FLAGS_IOC | GPD_FLAGS_HWO);
 
 	mreq->gpd = gpd;
+	trace_mtu3_prepare_gpd(mep, gpd);
 
 	return 0;
 }
@@ -431,6 +434,7 @@ static void qmu_tx_zlp_error_handler(struct mtu3 *mtu, u8 epnum)
 	}
 
 	dev_dbg(mtu->dev, "%s send ZLP for req=%p\n", __func__, mreq);
+	trace_mtu3_zlp_exp_gpd(mep, gpd_current);
 
 	mtu3_clrbits(mbase, MU3D_EP_TXCR0(mep->epnum), TX_DMAREQEN);
 
@@ -486,6 +490,7 @@ static void qmu_done_tx(struct mtu3 *mtu, u8 epnum)
 
 		request = &mreq->request;
 		request->actual = GPD_DATA_LEN(mtu, le32_to_cpu(gpd->dw3_info));
+		trace_mtu3_complete_gpd(mep, gpd);
 		mtu3_req_complete(mep, request, 0);
 
 		gpd = advance_deq_gpd(ring);
@@ -524,6 +529,7 @@ static void qmu_done_rx(struct mtu3 *mtu, u8 epnum)
 		req = &mreq->request;
 
 		req->actual = GPD_DATA_LEN(mtu, le32_to_cpu(gpd->dw3_info));
+		trace_mtu3_complete_gpd(mep, gpd);
 		mtu3_req_complete(mep, req, 0);
 
 		gpd = advance_deq_gpd(ring);
@@ -601,6 +607,7 @@ irqreturn_t mtu3_qmu_isr(struct mtu3 *mtu)
 	dev_dbg(mtu->dev, "=== QMUdone[tx=%x, rx=%x] QMUexp[%x] ===\n",
 		(qmu_done_status & 0xFFFF), qmu_done_status >> 16,
 		qmu_status);
+	trace_mtu3_qmu_isr(qmu_done_status, qmu_status);
 
 	if (qmu_done_status)
 		qmu_done_isr(mtu, qmu_done_status);

drivers/usb/mtu3/mtu3_trace.c

@@ -0,0 +1,23 @@
+// SPDX-License-Identifier: GPL-2.0
+/**
+ * mtu3_trace.c - trace support
+ *
+ * Copyright (C) 2019 MediaTek Inc.
+ *
+ * Author: Chunfeng Yun <chunfeng.yun@mediatek.com>
+ */
+
+#define CREATE_TRACE_POINTS
+#include "mtu3_trace.h"
+
+void mtu3_dbg_trace(struct device *dev, const char *fmt, ...)
+{
+	struct va_format vaf;
+	va_list args;
+
+	va_start(args, fmt);
+	vaf.fmt = fmt;
+	vaf.va = &args;
+	trace_mtu3_log(dev, &vaf);
+	va_end(args);
+}