[PATCH v4 1/2] usb: phy: show USB charger type for user

[PATCH v4 1/2] usb: phy: show USB charger type for user

[Peter Chen]

Current USB charger framework only shows charger state for user, but the
user may also need charger type for further use, add support for it.

Signed-off-by: Peter Chen <peter.chen@nxp.com>
---
Changes for v4:
- No changes.

 drivers/usb/phy/phy.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/phy/phy.c b/drivers/usb/phy/phy.c
index 0277f62739a2..ad2554630889 100644
--- a/drivers/usb/phy/phy.c
+++ b/drivers/usb/phy/phy.c
@@ -34,6 +34,14 @@ struct phy_devm {
 	struct notifier_block *nb;
 };
 
+static const char *const usb_chger_type[] = {
+	[UNKNOWN_TYPE]			= "USB_CHARGER_UNKNOWN_TYPE",
+	[SDP_TYPE]			= "USB_CHARGER_SDP_TYPE",
+	[CDP_TYPE]			= "USB_CHARGER_CDP_TYPE",
+	[DCP_TYPE]			= "USB_CHARGER_DCP_TYPE",
+	[ACA_TYPE]			= "USB_CHARGER_ACA_TYPE",
+};
+
 static struct usb_phy *__usb_find_phy(struct list_head *list,
 	enum usb_phy_type type)
 {
@@ -98,7 +106,8 @@ static void usb_phy_notify_charger_work(struct work_struct *work)
 {
 	struct usb_phy *usb_phy = container_of(work, struct usb_phy, chg_work);
 	char uchger_state[50] = { 0 };
-	char *envp[] = { uchger_state, NULL };
+	char uchger_type[50] = { 0 };
+	char *envp[] = { uchger_state, uchger_type, NULL };
 	unsigned int min, max;
 
 	switch (usb_phy->chg_state) {
@@ -122,6 +131,8 @@ static void usb_phy_notify_charger_work(struct work_struct *work)
 		return;
 	}
 
+	snprintf(uchger_type, ARRAY_SIZE(uchger_type),
+		 "USB_CHARGER_TYPE=%s", usb_chger_type[usb_phy->chg_type]);
 	kobject_uevent_env(&usb_phy->dev->kobj, KOBJ_CHANGE, envp);
 }
 
-- 
2.17.1

[PATCH v4 2/2] Doc: ABI: add usb charger uevent

[Peter Chen]

When the USB charger is inserted or removed, the users could get
USB charger state and type through the uevent.

Signed-off-by: Peter Chen <peter.chen@nxp.com>
---
Changes for v4
- Add explanation for charger type and related doc at usb.org

Changes for v3:
- Change kernel version for 5.6, and delete the kernel printk time

 Documentation/ABI/testing/usb-charger-uevent | 46 ++++++++++++++++++++
 1 file changed, 46 insertions(+)
 create mode 100644 Documentation/ABI/testing/usb-charger-uevent

diff --git a/Documentation/ABI/testing/usb-charger-uevent b/Documentation/ABI/testing/usb-charger-uevent
new file mode 100644
index 000000000000..419a92dd0d86
--- /dev/null
+++ b/Documentation/ABI/testing/usb-charger-uevent
@@ -0,0 +1,46 @@
+What:		Raise a uevent when a USB charger is inserted or removed
+Date:		2020-01-14
+KernelVersion:	5.6
+Contact:	linux-usb@vger.kernel.org
+Description:	There are two USB charger states:
+		USB_CHARGER_ABSENT
+		USB_CHARGER_PRESENT
+		There are five USB charger types:
+		USB_CHARGER_UNKNOWN_TYPE: Charger type is unknown
+		USB_CHARGER_SDP_TYPE: Standard Downstream Port
+		USB_CHARGER_CDP_TYPE: Charging Downstream Port
+		USB_CHARGER_DCP_TYPE: Dedicated Charging Port
+		USB_CHARGER_ACA_TYPE: Accessory Charging Adapter
+		https://www.usb.org/document-library/battery-charging-v12-spec-and-adopters-agreement
+
+		Here are two examples taken using udevadm monitor -p when
+		USB charger is online:
+		UDEV  change   /devices/soc0/usbphynop1 (platform)
+		ACTION=change
+		DEVPATH=/devices/soc0/usbphynop1
+		DRIVER=usb_phy_generic
+		MODALIAS=of:Nusbphynop1T(null)Cusb-nop-xceiv
+		OF_COMPATIBLE_0=usb-nop-xceiv
+		OF_COMPATIBLE_N=1
+		OF_FULLNAME=/usbphynop1
+		OF_NAME=usbphynop1
+		SEQNUM=2493
+		SUBSYSTEM=platform
+		USB_CHARGER_STATE=USB_CHARGER_PRESENT
+		USB_CHARGER_TYPE=USB_CHARGER_SDP_TYPE
+		USEC_INITIALIZED=227422826
+
+		USB charger is offline:
+		KERNEL change   /devices/soc0/usbphynop1 (platform)
+		ACTION=change
+		DEVPATH=/devices/soc0/usbphynop1
+		DRIVER=usb_phy_generic
+		MODALIAS=of:Nusbphynop1T(null)Cusb-nop-xceiv
+		OF_COMPATIBLE_0=usb-nop-xceiv
+		OF_COMPATIBLE_N=1
+		OF_FULLNAME=/usbphynop1
+		OF_NAME=usbphynop1
+		SEQNUM=2494
+		SUBSYSTEM=platform
+		USB_CHARGER_STATE=USB_CHARGER_ABSENT
+		USB_CHARGER_TYPE=USB_CHARGER_UNKNOWN_TYPE
-- 
2.17.1

Re: [PATCH v4 1/2] usb: phy: show USB charger type for user

[Greg KH]

On Thu, Jan 16, 2020 at 11:28:52AM +0800, Peter Chen wrote:
> Current USB charger framework only shows charger state for user, but the
> user may also need charger type for further use, add support for it.
> 
> Signed-off-by: Peter Chen <peter.chen@nxp.com>
> ---
> Changes for v4:
> - No changes.
> 
>  drivers/usb/phy/phy.c | 13 ++++++++++++-
>  1 file changed, 12 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/phy/phy.c b/drivers/usb/phy/phy.c
> index 0277f62739a2..ad2554630889 100644
> --- a/drivers/usb/phy/phy.c
> +++ b/drivers/usb/phy/phy.c
> @@ -34,6 +34,14 @@ struct phy_devm {
>  	struct notifier_block *nb;
>  };
>  
> +static const char *const usb_chger_type[] = {
> +	[UNKNOWN_TYPE]			= "USB_CHARGER_UNKNOWN_TYPE",
> +	[SDP_TYPE]			= "USB_CHARGER_SDP_TYPE",
> +	[CDP_TYPE]			= "USB_CHARGER_CDP_TYPE",
> +	[DCP_TYPE]			= "USB_CHARGER_DCP_TYPE",
> +	[ACA_TYPE]			= "USB_CHARGER_ACA_TYPE",
> +};

As these are exported values (CDP_TYPE and friends), they really need to
have explicit values on the .h file, otherwise it might not work
properly on all systems.

But that's kind of independant of this series, sorry, I just noticed it.

greg k-h

RE: [PATCH v4 1/2] usb: phy: show USB charger type for user

[Peter Chen]

 
> > Signed-off-by: Peter Chen <peter.chen@nxp.com>
> > ---
> > Changes for v4:
> > - No changes.
> >
> >  drivers/usb/phy/phy.c | 13 ++++++++++++-
> >  1 file changed, 12 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/usb/phy/phy.c b/drivers/usb/phy/phy.c index
> > 0277f62739a2..ad2554630889 100644
> > --- a/drivers/usb/phy/phy.c
> > +++ b/drivers/usb/phy/phy.c
> > @@ -34,6 +34,14 @@ struct phy_devm {
> >  	struct notifier_block *nb;
> >  };
> >
> > +static const char *const usb_chger_type[] = {
> > +	[UNKNOWN_TYPE]			=
> "USB_CHARGER_UNKNOWN_TYPE",
> > +	[SDP_TYPE]			= "USB_CHARGER_SDP_TYPE",
> > +	[CDP_TYPE]			= "USB_CHARGER_CDP_TYPE",
> > +	[DCP_TYPE]			= "USB_CHARGER_DCP_TYPE",
> > +	[ACA_TYPE]			= "USB_CHARGER_ACA_TYPE",
> > +};
> 
> As these are exported values (CDP_TYPE and friends), they really need to have
> explicit values on the .h file, otherwise it might not work properly on all systems.
> 

Sorry, what do you mean? These values are defined at include/uapi/linux/usb/charger.h

Peter

Re: [PATCH v4 1/2] usb: phy: show USB charger type for user

[Greg KH]

On Thu, Jan 30, 2020 at 02:05:17PM +0000, Peter Chen wrote:
>  
> > > Signed-off-by: Peter Chen <peter.chen@nxp.com>
> > > ---
> > > Changes for v4:
> > > - No changes.
> > >
> > >  drivers/usb/phy/phy.c | 13 ++++++++++++-
> > >  1 file changed, 12 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/usb/phy/phy.c b/drivers/usb/phy/phy.c index
> > > 0277f62739a2..ad2554630889 100644
> > > --- a/drivers/usb/phy/phy.c
> > > +++ b/drivers/usb/phy/phy.c
> > > @@ -34,6 +34,14 @@ struct phy_devm {
> > >  	struct notifier_block *nb;
> > >  };
> > >
> > > +static const char *const usb_chger_type[] = {
> > > +	[UNKNOWN_TYPE]			=
> > "USB_CHARGER_UNKNOWN_TYPE",
> > > +	[SDP_TYPE]			= "USB_CHARGER_SDP_TYPE",
> > > +	[CDP_TYPE]			= "USB_CHARGER_CDP_TYPE",
> > > +	[DCP_TYPE]			= "USB_CHARGER_DCP_TYPE",
> > > +	[ACA_TYPE]			= "USB_CHARGER_ACA_TYPE",
> > > +};
> > 
> > As these are exported values (CDP_TYPE and friends), they really need to have
> > explicit values on the .h file, otherwise it might not work properly on all systems.
> > 
> 
> Sorry, what do you mean? These values are defined at include/uapi/linux/usb/charger.h

Yes, but they are not set to a specific value, so they can really be
"anything".  That .h file needs to have specific numbers set to the
enum values in order for this to work properly on all arches/compilers.

thanks,

greg k-h