[PATCH v2 08/10] hikey960: Support usb functionality of Hikey960

[Yu Chen]

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: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: John Stultz <john.stultz@xxxxxxxxxx>
Cc: Binghui Wang <wangbinghui@xxxxxxxxxxxxx>
Cc: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
Signed-off-by: Yu Chen <chenyu56@xxxxxxxxxx>

---
v1:
* Using gpiod API with the gpios.
* Removing registering usb role switch.
* Registering usb role switch notifier.
v2:
* Fix license declaration.
* Add configuration of  gpio direction.
* Remove some log print.
---
---
 drivers/misc/Kconfig          |   6 ++
 drivers/misc/Makefile         |   1 +
 drivers/misc/hisi_hikey_usb.c | 181 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 188 insertions(+)
 create mode 100644 drivers/misc/hisi_hikey_usb.c

diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index f417b06e11c5..8d8b717759e2 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -521,6 +521,12 @@ config PVPANIC
 	  a paravirtualized device provided by QEMU; it lets a virtual machine
 	  (guest) communicate panic events to the host.
 
+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.
+
 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 e39ccbbc1b3a..dc8892b13a1a 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -59,3 +59,4 @@ obj-$(CONFIG_PCI_ENDPOINT_TEST)	+= pci_endpoint_test.o
 obj-$(CONFIG_OCXL)		+= ocxl/
 obj-y				+= cardreader/
 obj-$(CONFIG_PVPANIC)   	+= pvpanic.o
+obj-$(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..70013f8e76f0
--- /dev/null
+++ b/drivers/misc/hisi_hikey_usb.c
@@ -0,0 +1,181 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Support for usb functionality of Hikey series boards
+ * based on Hisilicon Kirin Soc.
+ *
+ * Copyright (C) 2017-2018 Hilisicon Electronics Co., Ltd.
+ *		http://www.huawei.com
+ *
+ * Authors: Yu Chen <chenyu56@xxxxxxxxxx>
+ */
+
+#include <linux/gpio/consumer.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/notifier.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/usb/role.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)
+{
+	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)
+{
+	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)
+{
+	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;
+
+	hisi_hikey_usb = container_of(nb, struct hisi_hikey_usb, nb);
+
+	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, "typec-vbus-enable-val",
+				   &hisi_hikey_usb->typec_vbus_enable_val);
+	if (ret)
+		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 (!hisi_hikey_usb->typec_vbus)
+		return -ENOENT;
+	else if (IS_ERR(hisi_hikey_usb->typec_vbus))
+		return PTR_ERR(hisi_hikey_usb->typec_vbus);
+
+	gpiod_direction_output(hisi_hikey_usb->typec_vbus,
+			!hisi_hikey_usb->typec_vbus_enable_val);
+
+	hisi_hikey_usb->otg_switch = devm_gpiod_get(dev, "otg-switch", GPIOD_IN);
+	if (!hisi_hikey_usb->otg_switch)
+		return -ENOENT;
+	else if (IS_ERR(hisi_hikey_usb->otg_switch))
+		return PTR_ERR(hisi_hikey_usb->otg_switch);
+
+	gpiod_direction_output(hisi_hikey_usb->otg_switch, USB_SWITCH_TO_HUB);
+
+	/* hub-vdd33-en is optional */
+	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);
+
+	gpiod_direction_output(hisi_hikey_usb->hub_vbus, HUB_VBUS_POWER_ON);
+
+	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))
+		return PTR_ERR(hisi_hikey_usb->role_sw);
+
+	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 = id_table_hisi_hikey_usb,
+	},
+};
+
+module_platform_driver(hisi_hikey_usb_driver);
+
+MODULE_AUTHOR("Yu Chen <chenyu56@xxxxxxxxxx>");
+MODULE_DESCRIPTION("Driver Support for USB functionality of Hikey");
+MODULE_LICENSE("GPL v2");
-- 
2.15.0-rc2