Add a debugfs interface - softconnect - for host mode to
connect/disconnect the devices without physically remove the
them.
This adds the capability to re-enumerate the devices which are
permanently mounted on the board with the MUSB controller
together.
Signed-off-by: Bin Liu <b-liu@xxxxxx>
---
drivers/usb/musb/musb_debugfs.c | 92 +++++++++++++++++++++++++++++++++++++++++
1 file changed, 92 insertions(+)
diff --git a/drivers/usb/musb/musb_debugfs.c b/drivers/usb/musb/musb_debugfs.c
index 04382ec..82b3be2 100644
--- a/drivers/usb/musb/musb_debugfs.c
+++ b/drivers/usb/musb/musb_debugfs.c
@@ -245,6 +245,91 @@ static const struct file_operations musb_test_mode_fops = {
.release = single_release,
};
+static int musb_softconnect_show(struct seq_file *s, void *unused)
+{
+ struct musb *musb = s->private;
+ u8 reg;
+ int connect;
+
+ switch (musb->xceiv->otg->state) {
+ case OTG_STATE_A_HOST:
+ case OTG_STATE_A_WAIT_BCON:
+ reg = musb_readb(musb->mregs, MUSB_DEVCTL);
+ connect = reg & MUSB_DEVCTL_SESSION ? 1 : 0;
+ break;
+ default:
+ connect = -1;
+ }
+
+ seq_printf(s, "%d\n", connect);
+
+ return 0;
+}
+
+static int musb_softconnect_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, musb_softconnect_show, inode->i_private);
+}
+
+static ssize_t musb_softconnect_write(struct file *file,
+ const char __user *ubuf, size_t count, loff_t *ppos)
+{
+ struct seq_file *s = file->private_data;
+ struct musb *musb = s->private;
+ char buf[2];
+ u8 reg;
+
+ memset(buf, 0x00, sizeof(buf));
+
+ if (copy_from_user(&buf, ubuf, min_t(size_t, sizeof(buf) - 1, count)))
+ return -EFAULT;
+
+ if (!strncmp(buf, "0", 1)) {
+ switch (musb->xceiv->otg->state) {
+ case OTG_STATE_A_HOST:
+ musb_root_disconnect(musb);
+ reg = musb_readb(musb->mregs, MUSB_DEVCTL);
+ reg &= ~MUSB_DEVCTL_SESSION;
+ musb_writeb(musb->mregs, MUSB_DEVCTL, reg);
+ break;
+ default:
+ break;
+ }
+
+ } else if (!strncmp(buf, "1", 1)) {
+ switch (musb->xceiv->otg->state) {
+ case OTG_STATE_A_WAIT_BCON:
+ /*
+ * musb_save_context() called in musb_runtime_suspend()
+ * might cache devctl with SESSION bit cleared during
+ * soft-disconnect, so specifically set SESSION bit
+ * here to preserve it for musb_runtime_resume().
+ */
+ musb->context.devctl |= MUSB_DEVCTL_SESSION;
+ reg = musb_readb(musb->mregs, MUSB_DEVCTL);
+ reg |= MUSB_DEVCTL_SESSION;
+ musb_writeb(musb->mregs, MUSB_DEVCTL, reg);
+ break;
+ default:
+ break;
+ }
+ }
+
+ return count;
+}
+
+/*
+ * In host mode, connect/disconnect the bus without physically
+ * remove the devices.
+ */
+static const struct file_operations musb_softconnect_fops = {
+ .open = musb_softconnect_open,
+ .write = musb_softconnect_write,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
int musb_init_debugfs(struct musb *musb)
{
struct dentry *root;
@@ -271,6 +356,13 @@ int musb_init_debugfs(struct musb *musb)
goto err1;
}
+ file = debugfs_create_file("softconnect", S_IRUGO | S_IWUSR,
+ root, musb, &musb_softconnect_fops);
+ if (!file) {
+ ret = -ENOMEM;
+ goto err1;
+ }
+
musb->debugfs_root = root;
return 0;
--
1.8.4
--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
