usb: dwc3: debugfs: add support for changing port mode

This makes testing a lot easier when trying to
switch between host and device modes.

Signed-off-by: Felipe Balbi <balbi@ti.com>

2 files changed, 83 insertions, 0 deletions

diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index 513a7391099f..6f1e8c98d78d 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -154,6 +154,7 @@
 #define DWC3_GCTL_CLK_PIPEHALF  (2)
 #define DWC3_GCTL_CLK_MASK      (3)
 
+#define DWC3_GCTL_PRTCAP(n)     (((n) & (3 << 12)) >> 12)
 #define DWC3_GCTL_PRTCAPDIR(n)  (n << 12)
 #define DWC3_GCTL_PRTCAP_HOST   1
 #define DWC3_GCTL_PRTCAP_DEVICE 2
diff --git a/drivers/usb/dwc3/debugfs.c b/drivers/usb/dwc3/debugfs.c
index da1ad77d8d51..fc49334a01cf 100644
--- a/drivers/usb/dwc3/debugfs.c
+++ b/drivers/usb/dwc3/debugfs.c
@@ -405,6 +405,80 @@ static const struct file_operations dwc3_regdump_fops = {
         .release                = single_release,
 };
 
+static int dwc3_mode_show(struct seq_file *s, void *unused)
+{
+        struct dwc3             *dwc = s->private;
+        unsigned long           flags;
+        u32                     reg;
+
+        spin_lock_irqsave(&dwc->lock, flags);
+        reg = dwc3_readl(dwc->regs, DWC3_GCTL);
+        spin_unlock_irqrestore(&dwc->lock, flags);
+
+        switch (DWC3_GCTL_PRTCAP(reg)) {
+        case DWC3_GCTL_PRTCAP_HOST:
+                seq_printf(s, "host\n");
+                break;
+        case DWC3_GCTL_PRTCAP_DEVICE:
+                seq_printf(s, "device\n");
+                break;
+        case DWC3_GCTL_PRTCAP_OTG:
+                seq_printf(s, "OTG\n");
+                break;
+        default:
+                seq_printf(s, "UNKNOWN %08x\n", DWC3_GCTL_PRTCAP(reg));
+        }
+
+        return 0;
+}
+
+static int dwc3_mode_open(struct inode *inode, struct file *file)
+{
+        return single_open(file, dwc3_mode_show, inode->i_private);
+}
+
+static ssize_t dwc3_mode_write(struct file *file,
+                const char __user *ubuf, size_t count, loff_t *ppos)
+{
+        struct seq_file         *s = file->private_data;
+        struct dwc3             *dwc = s->private;
+        unsigned long           flags;
+        u32                     reg;
+        char                    buf[32];
+
+        if (copy_from_user(&buf, ubuf, min_t(size_t, sizeof(buf) - 1, count)))
+                return -EFAULT;
+
+        spin_lock_irqsave(&dwc->lock, flags);
+        reg = dwc3_readl(dwc->regs, DWC3_GCTL);
+        spin_unlock_irqrestore(&dwc->lock, flags);
+
+        reg &= ~(DWC3_GCTL_PRTCAPDIR(DWC3_GCTL_PRTCAP_OTG));
+
+        if (!strncmp(buf, "host", 4))
+                reg |= DWC3_GCTL_PRTCAP(DWC3_GCTL_PRTCAP_HOST);
+
+        if (!strncmp(buf, "device", 6))
+                reg |= DWC3_GCTL_PRTCAP(DWC3_GCTL_PRTCAP_DEVICE);
+
+        if (!strncmp(buf, "otg", 3))
+                reg |= DWC3_GCTL_PRTCAP(DWC3_GCTL_PRTCAP_OTG);
+
+        spin_lock_irqsave(&dwc->lock, flags);
+        dwc3_writel(dwc->regs, DWC3_GCTL, reg);
+        spin_unlock_irqrestore(&dwc->lock, flags);
+
+        return count;
+}
+
+static const struct file_operations dwc3_mode_fops = {
+        .open                   = dwc3_mode_open,
+        .write                  = dwc3_mode_write,
+        .read                   = seq_read,
+        .llseek                 = seq_lseek,
+        .release                = single_release,
+};
+
 int __devinit dwc3_debugfs_init(struct dwc3 *dwc)
 {
         struct dentry           *root;
@@ -425,6 +499,14 @@ int __devinit dwc3_debugfs_init(struct dwc3 *dwc)
                 ret = PTR_ERR(file);
                 goto err1;
         }
+
+        file = debugfs_create_file("mode", S_IRUGO | S_IWUSR, root,
+                        dwc, &dwc3_mode_fops);
+        if (IS_ERR(file)) {
+                ret = PTR_ERR(file);
+                goto err1;
+        }
+
         return 0;
 
 err1: