On Mon, Dec 3, 2018 at 5:47 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 GPIOLIB

+       default n

No, Linus is not happy about this.
Default n _is_ a default.

+       help
+         If you say yes here you get support for usb functionality of HiSilicon Hikey Platform.

+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * hisi_hikey_usb.c
+ *
+ * Copyright (c) Hisilicon Tech. Co., Ltd. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */

Same comments to the above lines.

+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+#include <linux/of.h>
+#include <linux/gpio/consumer.h>
+#include <linux/usb/role.h>
+#include <linux/notifier.h>

Order?

+       pr_debug("%s: set hub power %d\n", __func__, value);

Noise.

+       pr_debug("%s: switch to %s\n", __func__, switch_to_str);

Noise.

+       pr_debug("%s: set typec vbus gpio to %d\n", __func__, value);

Noise.

+       if (!nb)
+               return -EINVAL;

On which conditions this happen?

+       pr_info("%s:set typec state to %lu\n", __func__, state);

Noise!

Guys, you perhaps can read about tracepoints and function tracer
facilities in the kernel.

+static int hisi_hikey_usb_probe(struct platform_device *pdev)
+{

+               pr_info("%s: typc_vbus_enable_val can't get\n", __func__);

Noise!

+       if (IS_ERR_OR_NULL(hisi_hikey_usb->typec_vbus)) {

So, this check is redundant. You are repeating it below.

+               if (!hisi_hikey_usb->typec_vbus)
+                       ret = -EINVAL;
+               else
+                       ret = PTR_ERR(hisi_hikey_usb->typec_vbus);
+               return ret;
+       }

+       if (IS_ERR_OR_NULL(hisi_hikey_usb->role_sw)) {

+               pr_err("%s: usb_role_switch_get failed\n", __func__);

Noise and same comment to the conditional check as above

+               if (!hisi_hikey_usb->role_sw)
+                       ret = -ENOENT;
+               else
+                       ret = PTR_ERR(hisi_hikey_usb->role_sw);
+               return ret;
+       }

+               .of_match_table = of_match_ptr(id_table_hisi_hikey_usb),

Does it compiles for non-OF case? Why macro is in use?

-- 
With Best Regards,
Andy Shevchenko