Patch adds feature that allow to change role from user space.

Signed-off-by: Pawel Laszczak <paw...@cadence.com>
---
 drivers/usb/cdns3/Makefile  |  2 +-
 drivers/usb/cdns3/core.c    |  2 +
 drivers/usb/cdns3/debugfs.c | 94 +++++++++++++++++++++++++++++++++++++
 drivers/usb/cdns3/drd.h     |  3 ++
 4 files changed, 100 insertions(+), 1 deletion(-)
 create mode 100644 drivers/usb/cdns3/debugfs.c

diff --git a/drivers/usb/cdns3/Makefile b/drivers/usb/cdns3/Makefile
index 34e60d03c4ec..08e6cdbebd46 100644
--- a/drivers/usb/cdns3/Makefile
+++ b/drivers/usb/cdns3/Makefile
@@ -1,7 +1,7 @@
 obj-$(CONFIG_USB_CDNS3)                        += cdns3.o
 obj-$(CONFIG_USB_CDNS3_PCI_WRAP)       += cdns3-pci.o
 
-cdns3-y                                        := core.o drd.o
+cdns3-y                                        := core.o drd.o debugfs.o
 cdns3-$(CONFIG_USB_CDNS3_GADGET)       += gadget.o ep0.o debug.o
 cdns3-$(CONFIG_USB_CDNS3_HOST)         += host.o
 cdns3-pci-y                            := cdns3-pci-wrap.o
diff --git a/drivers/usb/cdns3/core.c b/drivers/usb/cdns3/core.c
index 20ae9e76940e..4012f1007da9 100644
--- a/drivers/usb/cdns3/core.c
+++ b/drivers/usb/cdns3/core.c
@@ -309,6 +309,7 @@ static int cdns3_probe(struct platform_device *pdev)
        if (ret)
                goto err4;
 
+       cdns3_debugfs_init(cdns);
        device_set_wakeup_capable(dev, true);
        pm_runtime_set_active(dev);
        pm_runtime_enable(dev);
@@ -346,6 +347,7 @@ static int cdns3_remove(struct platform_device *pdev)
        pm_runtime_get_sync(&pdev->dev);
        pm_runtime_disable(&pdev->dev);
        pm_runtime_put_noidle(&pdev->dev);
+       cdns3_debugfs_exit(cdns);
        cdns3_remove_roles(cdns);
        usb_phy_shutdown(cdns->usbphy);
 
diff --git a/drivers/usb/cdns3/debugfs.c b/drivers/usb/cdns3/debugfs.c
new file mode 100644
index 000000000000..d4871bc1a69d
--- /dev/null
+++ b/drivers/usb/cdns3/debugfs.c
@@ -0,0 +1,94 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Cadence USBSS DRD Controller DebugFS filer.
+ *
+ * Copyright (C) 2018 Cadence.
+ *
+ * Author: Pawel Laszczak <paw...@cadence.com>
+ */
+
+#include <linux/types.h>
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+#include <linux/uaccess.h>
+
+#include "core.h"
+#include "gadget.h"
+
+static int cdns3_mode_show(struct seq_file *s, void *unused)
+{
+       struct cdns3            *cdns = s->private;
+
+       switch (cdns->role) {
+       case CDNS3_ROLE_HOST:
+               seq_puts(s, "host\n");
+               break;
+       case CDNS3_ROLE_GADGET:
+               seq_puts(s, "device\n");
+               break;
+       case CDNS3_ROLE_OTG:
+       case CDNS3_ROLE_END:
+               seq_puts(s, "otg\n");
+               break;
+       default:
+               seq_puts(s, "UNKNOWN mode\n");
+       }
+
+       return 0;
+}
+
+static int cdns3_mode_open(struct inode *inode, struct file *file)
+{
+       return single_open(file, cdns3_mode_show, inode->i_private);
+}
+
+static ssize_t cdns3_mode_write(struct file *file,
+                               const char __user *ubuf,
+                               size_t count, loff_t *ppos)
+{
+       struct seq_file         *s = file->private_data;
+       struct cdns3            *cdns = s->private;
+       u32                     mode = 0;
+       char                    buf[32];
+
+       if (copy_from_user(&buf, ubuf, min_t(size_t, sizeof(buf) - 1, count)))
+               return -EFAULT;
+
+       if (!strncmp(buf, "host", 4))
+               mode = USB_DR_MODE_HOST;
+
+       if (!strncmp(buf, "device", 6))
+               mode = USB_DR_MODE_PERIPHERAL;
+
+       if (!strncmp(buf, "otg", 3))
+               mode = USB_DR_MODE_OTG;
+
+       cdns->desired_role = mode;
+       queue_work(system_freezable_wq, &cdns->role_switch_wq);
+       return count;
+}
+
+static const struct file_operations cdns3_mode_fops = {
+       .open                   = cdns3_mode_open,
+       .write                  = cdns3_mode_write,
+       .read                   = seq_read,
+       .llseek                 = seq_lseek,
+       .release                = single_release,
+};
+
+void cdns3_debugfs_init(struct cdns3 *cdns)
+{
+       struct dentry *root;
+
+       root = debugfs_create_dir(dev_name(cdns->dev), NULL);
+       cdns->root = root;
+       if (IS_ENABLED(CONFIG_USB_CDNS3_GADGET) &&
+           IS_ENABLED(CONFIG_USB_CDNS3_HOST))
+               debugfs_create_file("mode", 0644, root, cdns,
+                                   &cdns3_mode_fops);
+}
+
+void cdns3_debugfs_exit(struct cdns3 *cdns)
+{
+       debugfs_remove_recursive(cdns->root);
+}
diff --git a/drivers/usb/cdns3/drd.h b/drivers/usb/cdns3/drd.h
index 85731f3b693c..5344290c76f2 100644
--- a/drivers/usb/cdns3/drd.h
+++ b/drivers/usb/cdns3/drd.h
@@ -119,4 +119,7 @@ int cdns3_drd_probe(struct cdns3 *cdns);
 void cdns3_set_hw_mode(struct cdns3 *cdns, u32 mode);
 irqreturn_t cdns3_drd_irq(struct cdns3 *cdns);
 
+void cdns3_debugfs_init(struct cdns3 *cdns);
+void cdns3_debugfs_exit(struct cdns3 *cdns);
+
 #endif /* __LINUX_CDNS3_DRD */
-- 
2.17.1

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