MLK-20754 usb: cdns3: add role switch sys entry

It is an experimental feature, and tested by internal team for
Carplay feature.

Signed-off-by: Peter Chen <peter.chen@nxp.com>
(cherry picked from commit 270c1ea5168763a03f79c4f9ecadb2cd18dc08f9)

diff --git a/Documentation/ABI/testing/sysfs-platform-cadence-usb3 b/Documentation/ABI/testing/sysfs-platform-cadence-usb3
new file mode 100644 (file)
index 0000000..c969518
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-platform-cadence-usb3
@@ -0,0 +1,9 @@
+What:          /sys/bus/platform/devices/5b110000.usb3/role
+Date:          Jan 2019
+Contact:       Peter Chen <peter.chen@nxp.com>
+Description:
+               It returns string "gadget", "host" and "none" when read it,
+               it indicates current controller role.
+
+               It will do role switch when write "gadget" or "host" to it.
+               Only controller at dual-role configuration supports writing.

diff --git a/drivers/usb/cdns3/core.c b/drivers/usb/cdns3/core.c
index b8a183f..063678b 100644 (file)
--- a/drivers/usb/cdns3/core.c
+++ b/drivers/usb/cdns3/core.c
@@ -499,6 +499,54 @@ static int cdns3_register_extcon(struct cdns3 *cdns)
        return 0;
 }
 
+static ssize_t cdns3_role_show(struct device *dev,
+               struct device_attribute *attr, char *buf)
+{
+       struct cdns3 *cdns = dev_get_drvdata(dev);
+
+       if (cdns->role != CDNS3_ROLE_END)
+               return sprintf(buf, "%s\n", cdns3_role(cdns)->name);
+       else
+               return sprintf(buf, "%s\n", "none");
+}
+
+static ssize_t cdns3_role_store(struct device *dev,
+               struct device_attribute *attr, const char *buf, size_t n)
+{
+       struct cdns3 *cdns = dev_get_drvdata(dev);
+       enum cdns3_roles role;
+       int ret;
+
+       if (!(cdns->roles[CDNS3_ROLE_HOST] && cdns->roles[CDNS3_ROLE_GADGET])) {
+               dev_warn(dev, "Current configuration is not dual-role, quit\n");
+               return -EPERM;
+       }
+
+       for (role = CDNS3_ROLE_HOST; role <= CDNS3_ROLE_GADGET; role++)
+               if (!strncmp(buf, cdns->roles[role]->name,
+                            strlen(cdns->roles[role]->name)))
+                       break;
+
+       if (role == cdns->role)
+               return -EINVAL;
+
+       disable_irq(cdns->irq);
+       ret = cdns3_do_role_switch(cdns, role);
+       enable_irq(cdns->irq);
+
+       return (ret == 0) ? n : ret;
+}
+static DEVICE_ATTR(role, 0644, cdns3_role_show, cdns3_role_store);
+
+static struct attribute *cdns3_attrs[] = {
+       &dev_attr_role.attr,
+       NULL,
+};
+
+static const struct attribute_group cdns3_attr_group = {
+       .attrs = cdns3_attrs,
+};
+
 /**
  * cdns3_probe - probe for cdns3 core device
  * @pdev: Pointer to cdns3 core platform device
@@ -613,6 +661,10 @@ static int cdns3_probe(struct platform_device *pdev)
        if (ret)
                goto err4;
 
+       ret = sysfs_create_group(&dev->kobj, &cdns3_attr_group);
+       if (ret)
+               goto err4;
+
        device_set_wakeup_capable(dev, true);
        pm_runtime_set_active(dev);
        pm_runtime_enable(dev);
@@ -648,13 +700,15 @@ err1:
 static int cdns3_remove(struct platform_device *pdev)
 {
        struct cdns3 *cdns = platform_get_drvdata(pdev);
+       struct device *dev = &pdev->dev;
 
-       pm_runtime_get_sync(&pdev->dev);
-       pm_runtime_disable(&pdev->dev);
-       pm_runtime_put_noidle(&pdev->dev);
+       pm_runtime_get_sync(dev);
+       pm_runtime_disable(dev);
+       pm_runtime_put_noidle(dev);
+       sysfs_remove_group(&dev->kobj, &cdns3_attr_group);
        cdns3_remove_roles(cdns);
        usb_phy_shutdown(cdns->usbphy);
-       cdns3_disable_unprepare_clks(&pdev->dev);
+       cdns3_disable_unprepare_clks(dev);
 
        return 0;
 }