[PATCH v3 2/2] usb: dwc3: add debugfs node to dump FIFO/Queue available space

From: changbin . du
Date: Fri Apr 08 2016 - 05:45:51 EST


From: "Du, Changbin" <changbin.du@xxxxxxxxx>

For DWC3 USB controller, the Global Debug Queue/FIFO Space Available
Register(GDBGFIFOSPACE) can be used to dump FIFO/Queue available space.
This can be used to check some special issues, like whether data is
successfully copied from memory to fifo when a trb is blocked.

Signed-off-by: Du, Changbin <changbin.du@xxxxxxxxx>
---
changes from v2:
no changes

---
drivers/usb/dwc3/core.h | 5 +++++
drivers/usb/dwc3/debugfs.c | 40 ++++++++++++++++++++++++++++++++++++++++
2 files changed, 45 insertions(+)

diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index 6254b2f..899cf76 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -348,6 +348,11 @@
#define DWC3_DSTS_LOWSPEED (2 << 0)
#define DWC3_DSTS_FULLSPEED1 (3 << 0)

+/* Global Debug Queue/FIFO Space Available Register */
+#define DWC3_GDBGFIFOSPACE_NUM(x) (((x) << 0) & 0x1F)
+#define DWC3_GDBGFIFOSPACE_TYPE(x) (((x) << 5) & 0xE0)
+#define DWC3_GDBGFIFOSPACE_GET_SPACE(x) (((x) >> 16) & 0xFFFF)
+
/* Device Generic Command Register */
#define DWC3_DGCMD_SET_LMP 0x01
#define DWC3_DGCMD_SET_PERIODIC_PAR 0x02
diff --git a/drivers/usb/dwc3/debugfs.c b/drivers/usb/dwc3/debugfs.c
index 071b286..02eaf54 100644
--- a/drivers/usb/dwc3/debugfs.c
+++ b/drivers/usb/dwc3/debugfs.c
@@ -426,6 +426,45 @@ static const struct file_operations dwc3_mode_fops = {
.release = single_release,
};

+static int dwc3_fifo_show(struct seq_file *s, void *unused)
+{
+ struct dwc3 *dwc = s->private;
+ unsigned long flags;
+ unsigned int type, index;
+ const char *name;
+ u32 reg;
+
+ static const char * const fifo_names[] = {
+ "TxFIFO", "RxFIFO", "TxReqQ", "RxReqQ", "RxInfoQ",
+ "DescFetchQ", "EventQ", "ProtocolStatusQ"};
+ spin_lock_irqsave(&dwc->lock, flags);
+ for (type = 0; type < 8; type++) {
+ name = fifo_names[type];
+ for (index = 0; index < 32; index++) {
+ dwc3_writel(dwc->regs, DWC3_GDBGFIFOSPACE,
+ DWC3_GDBGFIFOSPACE_NUM(index) |
+ DWC3_GDBGFIFOSPACE_TYPE(type));
+ reg = dwc3_readl(dwc->regs, DWC3_GDBGFIFOSPACE);
+ seq_printf(s, "%s%02d = %d\n", name, index,
+ DWC3_GDBGFIFOSPACE_GET_SPACE(reg));
+ }
+ }
+ spin_unlock_irqrestore(&dwc->lock, flags);
+ return 0;
+}
+
+static int dwc3_fifo_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, dwc3_fifo_show, inode->i_private);
+}
+
+static const struct file_operations dwc3_fifo_fops = {
+ .open = dwc3_fifo_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
static int dwc3_testmode_show(struct seq_file *s, void *unused)
{
struct dwc3 *dwc = s->private;
@@ -639,6 +678,7 @@ void dwc3_debugfs_init(struct dwc3 *dwc)
dwc->regset->base = dwc->regs;

debugfs_create_regset32("regdump", S_IRUGO, root, dwc->regset);
+ debugfs_create_file("fifo", S_IRUGO, root, dwc, &dwc3_fifo_fops);

if (IS_ENABLED(CONFIG_USB_DWC3_DUAL_ROLE))
debugfs_create_file("mode", S_IRUGO | S_IWUSR, root,
--
2.5.0