[PATCH v1 10/12] hikey960: Support usb functionality of Hikey960

[Yu Chen <chenyu56@huawei.com>]

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

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Binghui Wang <wangbinghui@hisilicon.com>
Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Yu Chen <chenyu56@huawei.com>

--
v1:
1) Using gpiod API with the gpios.
2) Removing registering usb role switch.
3) Registering usb role switch notifier.
--
---
 drivers/misc/Kconfig          |   7 ++
 drivers/misc/Makefile         |   1 +
 drivers/misc/hisi_hikey_usb.c | 198 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 206 insertions(+)
 create mode 100644 drivers/misc/hisi_hikey_usb.c

diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index 3726eacdf65d..8e04fc87b685 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -513,6 +513,13 @@ config MISC_RTSX
 	tristate
 	default MISC_RTSX_PCI || MISC_RTSX_USB
 
+config HISI_HIKEY_USB
+	tristate "USB functionality of HiSilicon Hikey Platform"
+	depends on GPIOLIB
+	default n
+	help
+	  If you say yes here you get support for usb functionality of HiSilicon Hikey Platform.
+
 source "drivers/misc/c2port/Kconfig"
 source "drivers/misc/eeprom/Kconfig"
 source "drivers/misc/cb710/Kconfig"
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index af22bbc3d00c..387dd302815c 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -58,3 +58,4 @@ obj-$(CONFIG_ASPEED_LPC_SNOOP)	+= aspeed-lpc-snoop.o
 obj-$(CONFIG_PCI_ENDPOINT_TEST)	+= pci_endpoint_test.o
 obj-$(CONFIG_OCXL)		+= ocxl/
 obj-$(CONFIG_MISC_RTSX)		+= cardreader/
+obj-$(CONFIG_HISI_HIKEY_USB)	+= hisi_hikey_usb.o
diff --git a/drivers/misc/hisi_hikey_usb.c b/drivers/misc/hisi_hikey_usb.c
new file mode 100644
index 000000000000..f320ed878e44
--- /dev/null
+++ b/drivers/misc/hisi_hikey_usb.c
@@ -0,0 +1,198 @@
+// 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.
+ *
+ */
+
+#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>
+
+#define DEVICE_DRIVER_NAME "hisi_hikey_usb"
+
+#define HUB_VBUS_POWER_ON 1
+#define HUB_VBUS_POWER_OFF 0
+#define USB_SWITCH_TO_HUB 1
+#define USB_SWITCH_TO_TYPEC 0
+
+struct hisi_hikey_usb {
+	struct gpio_desc *otg_switch;
+	struct gpio_desc *typec_vbus;
+	struct gpio_desc *hub_vbus;
+	int typec_vbus_enable_val;
+
+	struct usb_role_switch *role_sw;
+	struct notifier_block nb;
+};
+
+static void hub_power_ctrl(struct hisi_hikey_usb *hisi_hikey_usb, int value)
+{
+	pr_debug("%s: set hub power %d\n", __func__, value);
+	gpiod_set_value_cansleep(hisi_hikey_usb->hub_vbus, value);
+}
+
+static void usb_switch_ctrl(struct hisi_hikey_usb *hisi_hikey_usb,
+		int switch_to)
+{
+	const char *switch_to_str = (switch_to == USB_SWITCH_TO_HUB) ?
+		"hub" : "typec";
+
+	pr_debug("%s: switch to %s\n", __func__, switch_to_str);
+	gpiod_set_value_cansleep(hisi_hikey_usb->otg_switch, switch_to);
+}
+
+static void usb_typec_power_ctrl(struct hisi_hikey_usb *hisi_hikey_usb,
+		int value)
+{
+	pr_debug("%s: set typec vbus gpio to %d\n", __func__, value);
+	gpiod_set_value_cansleep(hisi_hikey_usb->typec_vbus, value);
+}
+
+static int hisi_hikey_role_switch(struct notifier_block *nb,
+			unsigned long state, void *data)
+{
+	struct hisi_hikey_usb *hisi_hikey_usb;
+
+	if (!nb)
+		return -EINVAL;
+
+	hisi_hikey_usb = container_of(nb, struct hisi_hikey_usb, nb);
+
+	pr_info("%s:set typec state to %lu\n", __func__, state);
+	switch (state) {
+	case USB_ROLE_NONE:
+		usb_typec_power_ctrl(hisi_hikey_usb,
+				!hisi_hikey_usb->typec_vbus_enable_val);
+		usb_switch_ctrl(hisi_hikey_usb, USB_SWITCH_TO_HUB);
+		hub_power_ctrl(hisi_hikey_usb, HUB_VBUS_POWER_ON);
+		break;
+	case USB_ROLE_HOST:
+		usb_switch_ctrl(hisi_hikey_usb, USB_SWITCH_TO_TYPEC);
+		usb_typec_power_ctrl(hisi_hikey_usb,
+				hisi_hikey_usb->typec_vbus_enable_val);
+		break;
+	case USB_ROLE_DEVICE:
+		hub_power_ctrl(hisi_hikey_usb, HUB_VBUS_POWER_OFF);
+		usb_typec_power_ctrl(hisi_hikey_usb,
+				!hisi_hikey_usb->typec_vbus_enable_val);
+		usb_switch_ctrl(hisi_hikey_usb, USB_SWITCH_TO_TYPEC);
+		break;
+	default:
+		break;
+	}
+
+	return 0;
+}
+
+static int hisi_hikey_usb_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *root = dev->of_node;
+	struct hisi_hikey_usb *hisi_hikey_usb;
+	int ret;
+
+	hisi_hikey_usb = devm_kzalloc(dev, sizeof(*hisi_hikey_usb), GFP_KERNEL);
+	if (!hisi_hikey_usb)
+		return -ENOMEM;
+
+	hisi_hikey_usb->nb.notifier_call = hisi_hikey_role_switch;
+
+	ret = of_property_read_u32(root, "typc-vbus-enable-val",
+				   &hisi_hikey_usb->typec_vbus_enable_val);
+	if (ret) {
+		pr_info("%s: typc_vbus_enable_val can't get\n", __func__);
+		hisi_hikey_usb->typec_vbus_enable_val = 1;
+	}
+
+	hisi_hikey_usb->typec_vbus = devm_gpiod_get(dev, "typec-vbus",
+			hisi_hikey_usb->typec_vbus_enable_val ?
+			GPIOD_OUT_LOW : GPIOD_OUT_HIGH);
+	if (IS_ERR_OR_NULL(hisi_hikey_usb->typec_vbus)) {
+		if (!hisi_hikey_usb->typec_vbus)
+			ret = -EINVAL;
+		else
+			ret = PTR_ERR(hisi_hikey_usb->typec_vbus);
+		return ret;
+	}
+
+	hisi_hikey_usb->otg_switch = devm_gpiod_get(dev, "otg-switch", GPIOD_IN);
+	if (IS_ERR(hisi_hikey_usb->otg_switch))
+		return PTR_ERR(hisi_hikey_usb->otg_switch);
+
+	hisi_hikey_usb->hub_vbus = devm_gpiod_get(dev, "hub-vdd33-en",
+			GPIOD_OUT_LOW);
+	if (IS_ERR(hisi_hikey_usb->hub_vbus))
+		return PTR_ERR(hisi_hikey_usb->hub_vbus);
+
+	hisi_hikey_usb->role_sw = usb_role_switch_get(dev);
+	if (IS_ERR_OR_NULL(hisi_hikey_usb->role_sw)) {
+		pr_err("%s: usb_role_switch_get failed\n", __func__);
+		if (!hisi_hikey_usb->role_sw)
+			ret = -ENOENT;
+		else
+			ret = PTR_ERR(hisi_hikey_usb->role_sw);
+		return ret;
+	}
+
+	ret = usb_role_switch_register_notifier(hisi_hikey_usb->role_sw,
+			&hisi_hikey_usb->nb);
+	if (ret) {
+		usb_role_switch_put(hisi_hikey_usb->role_sw);
+		return ret;
+	}
+
+	platform_set_drvdata(pdev, hisi_hikey_usb);
+
+	return 0;
+}
+
+static int  hisi_hikey_usb_remove(struct platform_device *pdev)
+{
+	struct hisi_hikey_usb *hisi_hikey_usb = platform_get_drvdata(pdev);
+
+	usb_role_switch_unregister_notifier(hisi_hikey_usb->role_sw,
+			&hisi_hikey_usb->nb);
+
+	usb_role_switch_put(hisi_hikey_usb->role_sw);
+
+	return 0;
+}
+
+static const struct of_device_id id_table_hisi_hikey_usb[] = {
+	{.compatible = "hisilicon,gpio_hubv1"},
+	{.compatible = "hisilicon,hikey960_usb"},
+	{}
+};
+
+static struct platform_driver  hisi_hikey_usb_driver = {
+	.probe = hisi_hikey_usb_probe,
+	.remove = hisi_hikey_usb_remove,
+	.driver = {
+		.name = DEVICE_DRIVER_NAME,
+		.of_match_table = of_match_ptr(id_table_hisi_hikey_usb),
+
+	},
+};
+
+module_platform_driver(hisi_hikey_usb_driver);
+
+MODULE_AUTHOR("Yu Chen <chenyu56@huawei.com>");
+MODULE_DESCRIPTION("Driver Support for USB functionality of Hikey");
+MODULE_LICENSE("GPL v2");
-- 
2.15.0-rc2