On Sat, Mar 2, 2019 at 11:05 AM Yu Chen [off-list ref] wrote:

This driver handles usb hub power on and typeC port event of HiKey960 board:
1)DP&DM switching between usb hub and typeC port base on typeC port
state
2)Control power of usb hub on Hikey960
3)Control vbus of typeC port

+config HISI_HIKEY_USB
+       tristate "USB functionality of HiSilicon Hikey Platform"
+       depends on OF && GPIOLIB
+       help
+         If you say yes here you get support for usb functionality of HiSilicon Hikey Platform.

+#include <linux/of.h>

It's hard to see why this have
depends on OF followed by above header inclusion.

+       hisi_hikey_usb->typec_vbus = devm_gpiod_get(dev, "typec-vbus",
+                       GPIOD_OUT_LOW);

+       if (!hisi_hikey_usb->typec_vbus)
+               return -ENOENT;

Hmm... Is it possible to get NULL pointer from gpiod_get() at all?

+       if (!hisi_hikey_usb->otg_switch)
+               return -ENOENT;

Ditto.

+       /* hub-vdd33-en is optional */
+       hisi_hikey_usb->hub_vbus = devm_gpiod_get(dev, "hub-vdd33-en",
+                       GPIOD_OUT_HIGH);

devm_gpio_get_optional() if it's indeed optional.

+       hisi_hikey_usb->role_sw = usb_role_switch_get(dev);
+       if (!hisi_hikey_usb->role_sw)
+               return -EPROBE_DEFER;

+       else if (IS_ERR(hisi_hikey_usb->role_sw))

Redundant 'else'

+               return PTR_ERR(hisi_hikey_usb->role_sw);

+static const struct of_device_id id_table_hisi_hikey_usb[] = {
+       {.compatible = "hisilicon,gpio_hubv1"},
+       {.compatible = "hisilicon,hikey960_usb"},
+       {}
+};

MODULE_DEVICE_TABLE()?

-- 
With Best Regards,
Andy Shevchenko