| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Date: Mon, 27 Jul 2020 17:02:59 +0200
From: Paul Cercueil <paul@...pouillou.net>
To: Chunfeng Yun <chunfeng.yun@...iatek.com>
Cc: Andy Shevchenko <andy.shevchenko@...il.com>,
Chanwoo Choi <cw00.choi@...sung.com>,
MyungJoo Ham <myungjoo.ham@...sung.com>,
Greg Kroah-Hartman <gregkh@...uxfoundation.org>, od@...c.me,
USB <linux-usb@...r.kernel.org>,
Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: [RESEND PATCH] usb: common: usb-conn-gpio: Register optional
charger
Le lun. 27 juil. 2020 à 13:42, Chunfeng Yun
<chunfeng.yun@...iatek.com> a écrit :
> On Sun, 2020-07-26 at 12:27 +0200, Paul Cercueil wrote:
>>
>> Le dim. 26 juil. 2020 à 13:14, Andy Shevchenko
>> <andy.shevchenko@...il.com> a écrit :
>> > On Mon, Jun 22, 2020 at 1:51 AM Paul Cercueil
>> <paul@...pouillou.net>
>> > wrote:
>> >>
>> >> Register a power supply charger, if the Kconfig option
>> >> USB_CONN_GPIO_CHARGER is set, whose online state depends on
>> whether
>> >> the USB role is set to device or not.
>> >>
>> >> This is useful when the USB role is the only way to know if the
>> >> device
>> >> is charging from USB. The API is the standard power supply
>> charger
>> >> API,
>> >> you get a /sys/class/power_supply/xxx/online node which tells
>> you
>> >> the
>> >> state of the charger.
>> >>
>> >> The sole purpose of this is to give userspace applications a
>> way to
>> >> know whether or not the charger is plugged.
>> >
>> > I'm not sure I understand the purpose of this (third?) way to
>> detect
>> > USB charger and notify user space about.
>> > Why is extcon not good enough?
>>
>> We can't have extcon and USB role detection at the same time.
>>
>> -Paul
>>
>> >> Signed-off-by: Paul Cercueil <paul@...pouillou.net>
>> >> ---
>> >> drivers/usb/common/Kconfig | 11 +++++++
>> >> drivers/usb/common/usb-conn-gpio.c | 47
>> >> ++++++++++++++++++++++++++++++
>> >> 2 files changed, 58 insertions(+)
>> >>
>> >> diff --git a/drivers/usb/common/Kconfig
>> b/drivers/usb/common/Kconfig
>> >> index d611477aae41..5405ae96c68f 100644
>> >> --- a/drivers/usb/common/Kconfig
>> >> +++ b/drivers/usb/common/Kconfig
>> >> @@ -49,3 +49,14 @@ config USB_CONN_GPIO
>> >>
>> >> To compile the driver as a module, choose M here: the
>> >> module will
>> >> be called usb-conn-gpio.ko
>> >> +
>> >> +if USB_CONN_GPIO
>> >> +
>> >> +config USB_CONN_GPIO_CHARGER
>> >> + bool "USB charger support"
>> >> + select POWER_SUPPLY
>> >> + help
>> >> + Register a charger with the power supply subsystem.
>> This
>> >> will allow
>> >> + userspace to know whether or not the device is
>> charging
>> >> from USB.
>> >> +
>> >> +endif
>> >> diff --git a/drivers/usb/common/usb-conn-gpio.c
>> >> b/drivers/usb/common/usb-conn-gpio.c
>> >> index ed204cbb63ea..129d48db280b 100644
>> >> --- a/drivers/usb/common/usb-conn-gpio.c
>> >> +++ b/drivers/usb/common/usb-conn-gpio.c
>> >> @@ -17,6 +17,7 @@
>> >> #include <linux/of.h>
>> >> #include <linux/pinctrl/consumer.h>
>> >> #include <linux/platform_device.h>
>> >> +#include <linux/power_supply.h>
>> >> #include <linux/regulator/consumer.h>
>> >> #include <linux/usb/role.h>
>> >>
>> >> @@ -38,6 +39,9 @@ struct usb_conn_info {
>> >> struct gpio_desc *vbus_gpiod;
>> >> int id_irq;
>> >> int vbus_irq;
>> >> +
>> >> + struct power_supply_desc desc;
>> >> + struct power_supply *charger;
>> >> };
>> >>
>> >> /**
>> >> @@ -98,6 +102,8 @@ static void usb_conn_detect_cable(struct
>> >> work_struct *work)
>> >> ret = regulator_enable(info->vbus);
>> >> if (ret)
>> >> dev_err(info->dev, "enable vbus
>> regulator
>> >> failed\n");
>> >> + } else if (IS_ENABLED(CONFIG_USB_CONN_GPIO_CHARGER)) {
>> >> + power_supply_changed(info->charger);
>> >> }
>> >>
>> >> info->last_role = role;
>> >> @@ -121,10 +127,35 @@ static irqreturn_t usb_conn_isr(int irq,
>> void
>> >> *dev_id)
>> >> return IRQ_HANDLED;
>> >> }
>> >>
>> >> +static enum power_supply_property usb_charger_properties[] = {
>> >> + POWER_SUPPLY_PROP_ONLINE,
>> >> +};
>> >> +
>> >> +static int usb_charger_get_property(struct power_supply *psy,
>> >> + enum power_supply_property
>> psp,
>> >> + union power_supply_propval
>> *val)
>> >> +{
>> >> + struct usb_conn_info *info =
>> power_supply_get_drvdata(psy);
>> >> +
>> >> + switch (psp) {
>> >> + case POWER_SUPPLY_PROP_ONLINE:
>> >> + val->intval = info->last_role ==
>> USB_ROLE_DEVICE;
> What will happen if you not change info->last_role here?
> I prefer it's only changed by usb_conn_isr(), if it's changed by other
> drivers, for example, through power_supply_get_property(), may skip
> role
> switch.
If you read carefully, info->last_role is not modified here :)
-Paul
>
>> >> + break;
>> >> + default:
>> >> + return -EINVAL;
>> >> + }
>> >> +
>> >> + return 0;
>> >> +}
>> >> +
>> >> static int usb_conn_probe(struct platform_device *pdev)
>> >> {
>> >> struct device *dev = &pdev->dev;
>> >> + struct power_supply_desc *desc;
>> >> struct usb_conn_info *info;
>> >> + struct power_supply_config cfg = {
>> >> + .of_node = dev->of_node,
>> >> + };
>> >> int ret = 0;
>> >>
>> >> info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
>> >> @@ -203,6 +234,22 @@ static int usb_conn_probe(struct
>> >> platform_device *pdev)
>> >> }
>> >> }
>> >>
>> >> + if (IS_ENABLED(CONFIG_USB_CONN_GPIO_CHARGER)) {
>> >> + desc = &info->desc;
>> >> + desc->name = "usb-charger";
>> >> + desc->properties = usb_charger_properties;
>> >> + desc->num_properties =
>> >> ARRAY_SIZE(usb_charger_properties);
>> >> + desc->get_property = usb_charger_get_property;
>> >> + desc->type = POWER_SUPPLY_TYPE_USB;
>> >> + cfg.drv_data = info;
>> >> +
>> >> + info->charger = devm_power_supply_register(dev,
>> >> desc, &cfg);
>> >> + if (IS_ERR(info->charger)) {
>> >> + dev_err(dev, "Unable to register
>> >> charger\n");
>> >> + return PTR_ERR(info->charger);
>> >> + }
>> >> + }
>> >> +
>> >> platform_set_drvdata(pdev, info);
>> >>
>> >> /* Perform initial detection */
>> >> --
>> >> 2.27.0
>> >>
>> >
>> >
>> > --
>> > With Best Regards,
>> > Andy Shevchenko
>>
>>
>
Powered by blists - more mailing lists