[PATCH] usb: introduce usb_ep_type_string() function

From: Chunfeng Yun
Date: Fri Mar 01 2019 - 01:58:54 EST


In some places, the code prints a human-readable USB endpoint
transfer type (e.g. "bulk"). This involves a switch statement
sometimes wrapped around in ({ ... }) block leading to code
repetition.
To make this scenario easier, here introduces usb_ep_type_string()
function, which returns a human-readable name of provided
endpoint type.
It also changes a few places switch was used to use this
new function.

Signed-off-by: Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx>
---
drivers/usb/common/common.c | 16 ++++++++++++++++
drivers/usb/core/endpoint.c | 18 ++----------------
drivers/usb/core/hcd.c | 17 ++---------------
drivers/usb/dwc3/debugfs.c | 23 ++++-------------------
drivers/usb/gadget/udc/aspeed-vhub/epn.c | 6 +-----
drivers/usb/gadget/udc/dummy_hcd.c | 16 +---------------
drivers/usb/host/xhci-trace.h | 19 ++-----------------
include/linux/usb/ch9.h | 8 ++++++++
8 files changed, 36 insertions(+), 87 deletions(-)

diff --git a/drivers/usb/common/common.c b/drivers/usb/common/common.c
index 48277bbc15e4..2174dd9ec176 100644
--- a/drivers/usb/common/common.c
+++ b/drivers/usb/common/common.c
@@ -16,6 +16,22 @@
#include <linux/usb/otg.h>
#include <linux/of_platform.h>

+static const char *const ep_type_names[] = {
+ [USB_ENDPOINT_XFER_CONTROL] = "ctrl",
+ [USB_ENDPOINT_XFER_ISOC] = "isoc",
+ [USB_ENDPOINT_XFER_BULK] = "bulk",
+ [USB_ENDPOINT_XFER_INT] = "intr",
+};
+
+const char *usb_ep_type_string(int ep_type)
+{
+ if (ep_type < 0 || ep_type >= ARRAY_SIZE(ep_type_names))
+ return "unknown";
+
+ return ep_type_names[ep_type];
+}
+EXPORT_SYMBOL_GPL(usb_ep_type_string);
+
const char *usb_otg_state_string(enum usb_otg_state state)
{
static const char *const names[] = {
diff --git a/drivers/usb/core/endpoint.c b/drivers/usb/core/endpoint.c
index 1c2c04079676..afa43f9a47b2 100644
--- a/drivers/usb/core/endpoint.c
+++ b/drivers/usb/core/endpoint.c
@@ -60,23 +60,9 @@ static ssize_t type_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct ep_device *ep = to_ep_device(dev);
- char *type = "unknown";
+ int ep_type = usb_endpoint_type(ep->desc);

- switch (usb_endpoint_type(ep->desc)) {
- case USB_ENDPOINT_XFER_CONTROL:
- type = "Control";
- break;
- case USB_ENDPOINT_XFER_ISOC:
- type = "Isoc";
- break;
- case USB_ENDPOINT_XFER_BULK:
- type = "Bulk";
- break;
- case USB_ENDPOINT_XFER_INT:
- type = "Interrupt";
- break;
- }
- return sprintf(buf, "%s\n", type);
+ return sprintf(buf, "%s\n", usb_ep_type_string(ep_type));
}
static DEVICE_ATTR_RO(type);

diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index 015b126ce455..193ee92b2fdb 100644
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -1875,23 +1875,10 @@ void usb_hcd_flush_endpoint(struct usb_device *udev,
/* kick hcd */
unlink1(hcd, urb, -ESHUTDOWN);
dev_dbg (hcd->self.controller,
- "shutdown urb %pK ep%d%s%s\n",
+ "shutdown urb %pK ep%d%s-%s\n",
urb, usb_endpoint_num(&ep->desc),
is_in ? "in" : "out",
- ({ char *s;
-
- switch (usb_endpoint_type(&ep->desc)) {
- case USB_ENDPOINT_XFER_CONTROL:
- s = ""; break;
- case USB_ENDPOINT_XFER_BULK:
- s = "-bulk"; break;
- case USB_ENDPOINT_XFER_INT:
- s = "-intr"; break;
- default:
- s = "-iso"; break;
- };
- s;
- }));
+ usb_ep_type_string(usb_endpoint_type(&ep->desc)));
usb_put_urb (urb);

/* list contents may have changed */
diff --git a/drivers/usb/dwc3/debugfs.c b/drivers/usb/dwc3/debugfs.c
index 1c792710348f..d9e2a63835fe 100644
--- a/drivers/usb/dwc3/debugfs.c
+++ b/drivers/usb/dwc3/debugfs.c
@@ -750,28 +750,13 @@ static int dwc3_transfer_type_show(struct seq_file *s, void *unused)
unsigned long flags;

spin_lock_irqsave(&dwc->lock, flags);
- if (!(dep->flags & DWC3_EP_ENABLED) ||
- !dep->endpoint.desc) {
- seq_printf(s, "--\n");
+ if (!(dep->flags & DWC3_EP_ENABLED) || !dep->endpoint.desc) {
+ seq_puts(s, "unknown\n");
goto out;
}

- switch (usb_endpoint_type(dep->endpoint.desc)) {
- case USB_ENDPOINT_XFER_CONTROL:
- seq_printf(s, "control\n");
- break;
- case USB_ENDPOINT_XFER_ISOC:
- seq_printf(s, "isochronous\n");
- break;
- case USB_ENDPOINT_XFER_BULK:
- seq_printf(s, "bulk\n");
- break;
- case USB_ENDPOINT_XFER_INT:
- seq_printf(s, "interrupt\n");
- break;
- default:
- seq_printf(s, "--\n");
- }
+ seq_printf(s, "%s\n",
+ usb_ep_type_string(usb_endpoint_type(dep->endpoint.desc)));

out:
spin_unlock_irqrestore(&dwc->lock, flags);
diff --git a/drivers/usb/gadget/udc/aspeed-vhub/epn.c b/drivers/usb/gadget/udc/aspeed-vhub/epn.c
index 4a28e3fbeb0b..165b0a43670e 100644
--- a/drivers/usb/gadget/udc/aspeed-vhub/epn.c
+++ b/drivers/usb/gadget/udc/aspeed-vhub/epn.c
@@ -593,10 +593,6 @@ static int ast_vhub_epn_disable(struct usb_ep* u_ep)
static int ast_vhub_epn_enable(struct usb_ep* u_ep,
const struct usb_endpoint_descriptor *desc)
{
- static const char *ep_type_string[] __maybe_unused = { "ctrl",
- "isoc",
- "bulk",
- "intr" };
struct ast_vhub_ep *ep = to_ast_ep(u_ep);
struct ast_vhub_dev *dev;
struct ast_vhub *vhub;
@@ -646,7 +642,7 @@ static int ast_vhub_epn_enable(struct usb_ep* u_ep,
ep->epn.wedged = false;

EPDBG(ep, "Enabling [%s] %s num %d maxpacket=%d\n",
- ep->epn.is_in ? "in" : "out", ep_type_string[type],
+ ep->epn.is_in ? "in" : "out", usb_ep_type_string(type),
usb_endpoint_num(desc), maxpacket);

/* Can we use DMA descriptor mode ? */
diff --git a/drivers/usb/gadget/udc/dummy_hcd.c b/drivers/usb/gadget/udc/dummy_hcd.c
index baf72f95f0f1..40c6a484e232 100644
--- a/drivers/usb/gadget/udc/dummy_hcd.c
+++ b/drivers/usb/gadget/udc/dummy_hcd.c
@@ -617,21 +617,7 @@ static int dummy_enable(struct usb_ep *_ep,
_ep->name,
desc->bEndpointAddress & 0x0f,
(desc->bEndpointAddress & USB_DIR_IN) ? "in" : "out",
- ({ char *val;
- switch (usb_endpoint_type(desc)) {
- case USB_ENDPOINT_XFER_BULK:
- val = "bulk";
- break;
- case USB_ENDPOINT_XFER_ISOC:
- val = "iso";
- break;
- case USB_ENDPOINT_XFER_INT:
- val = "intr";
- break;
- default:
- val = "ctrl";
- break;
- } val; }),
+ usb_ep_type_string(usb_endpoint_type(desc)),
max, ep->stream_en ? "enabled" : "disabled");

/* at this point real hardware should be NAKing transfers
diff --git a/drivers/usb/host/xhci-trace.h b/drivers/usb/host/xhci-trace.h
index 88b427434bd8..bac73d688f11 100644
--- a/drivers/usb/host/xhci-trace.h
+++ b/drivers/usb/host/xhci-trace.h
@@ -289,23 +289,8 @@ DECLARE_EVENT_CLASS(xhci_log_urb,
),
TP_printk("ep%d%s-%s: urb %p pipe %u slot %d length %d/%d sgs %d/%d stream %d flags %08x",
__entry->epnum, __entry->dir_in ? "in" : "out",
- ({ char *s;
- switch (__entry->type) {
- case USB_ENDPOINT_XFER_INT:
- s = "intr";
- break;
- case USB_ENDPOINT_XFER_CONTROL:
- s = "control";
- break;
- case USB_ENDPOINT_XFER_BULK:
- s = "bulk";
- break;
- case USB_ENDPOINT_XFER_ISOC:
- s = "isoc";
- break;
- default:
- s = "UNKNOWN";
- } s; }), __entry->urb, __entry->pipe, __entry->slot_id,
+ usb_ep_type_string(__entry->type),
+ __entry->urb, __entry->pipe, __entry->slot_id,
__entry->actual, __entry->length, __entry->num_mapped_sgs,
__entry->num_sgs, __entry->stream, __entry->flags
)
diff --git a/include/linux/usb/ch9.h b/include/linux/usb/ch9.h
index 523aa088f6ab..da82606be605 100644
--- a/include/linux/usb/ch9.h
+++ b/include/linux/usb/ch9.h
@@ -36,6 +36,14 @@
#include <linux/device.h>
#include <uapi/linux/usb/ch9.h>

+/**
+ * usb_ep_type_string() - Returns human readable-name of the endpoint type.
+ * @ep_type: The endpoint type to return human-readable name for. If it's not
+ * any of the types: USB_ENDPOINT_XFER_{CONTROL, ISOC, BULK, INT},
+ * usually got by usb_endpoint_type(), the string 'unknown' will be returned.
+ */
+extern const char *usb_ep_type_string(int ep_type);
+
/**
* usb_speed_string() - Returns human readable-name of the speed.
* @speed: The speed to return human-readable name for. If it's not
--
2.20.1