Re: [PATCH v3 10/12] hikey960: Support usb functionality of Hikey960

[Chunfeng Yun <chunfeng.yun@mediatek.com>]

hi,
On Sat, 2019-03-02 at 17:05 +0800, Yu Chen 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
> 
> Cc: Chunfeng Yun <chunfeng.yun@mediatek.com>
> Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
> 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:
> * 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.
> v3:
> * Remove property of "typec_vbus_enable_val".
> * Remove gpiod_direction_output and set initial value of gpio by devm_gpiod_get.
> ---
> ---
>  drivers/misc/Kconfig          |   6 ++
>  drivers/misc/Makefile         |   1 +
>  drivers/misc/hisi_hikey_usb.c | 167 ++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 174 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..85d6fee468c0
> --- /dev/null
> +++ b/drivers/misc/hisi_hikey_usb.c
> @@ -0,0 +1,167 @@
> +// 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@huawei.com>
> + */
> +
> +#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
> +#define TYPEC_VBUS_POWER_ON 1
> +#define TYPEC_VBUS_POWER_OFF 0
> +
> +struct hisi_hikey_usb {
> +	struct gpio_desc *otg_switch;
> +	struct gpio_desc *typec_vbus;
> +	struct gpio_desc *hub_vbus;
> +
> +	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, TYPEC_VBUS_POWER_OFF);
> +		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, TYPEC_VBUS_POWER_ON);
> +		break;
> +	case USB_ROLE_DEVICE:
> +		hub_power_ctrl(hisi_hikey_usb, HUB_VBUS_POWER_OFF);
> +		usb_typec_power_ctrl(hisi_hikey_usb, TYPEC_VBUS_POWER_OFF);
> +		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;
> +
> +	hisi_hikey_usb->typec_vbus = devm_gpiod_get(dev, "typec-vbus",
> +			GPIOD_OUT_LOW);
> +	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);
> +
> +	hisi_hikey_usb->otg_switch = devm_gpiod_get(dev, "otg-switch",
> +			GPIOD_OUT_HIGH);
> +	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);
> +
> +	/* hub-vdd33-en is optional */
> +	hisi_hikey_usb->hub_vbus = devm_gpiod_get(dev, "hub-vdd33-en",
> +			GPIOD_OUT_HIGH);
> +	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 (!hisi_hikey_usb->role_sw)
> +		return -EPROBE_DEFER;
Here return EPROBE_DEFFER means the related device_connection is
registered after this probe is called, right?
if not, use IS_ERR_OR_NULL then return PTR_ERR is enough
> +	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@huawei.com>");
> +MODULE_DESCRIPTION("Driver Support for USB functionality of Hikey");
> +MODULE_LICENSE("GPL v2");