[PATCH 0/3] Add vbus draw support to DWC3

[PATCH 0/3] Add vbus draw support to DWC3

[Wesley Cheng]

Some devices are connected to standard downstream ports (SDP) and draw current
from them.  The current rates are defined in the BC1.2 specification, and
highlights the different charge rates depending on the device state.  The DWC3
gadget does not currently have a mechanism to notify external drivers about
how much current can be drawn.

The current rates are notified by the USB gadget layer, and the DWC3 gadget will
propagate this potentially to external charger drivers.  Also, the USB gadget
needs to be fixed to only allow 100mA current draw when receiving a bus reset
from the host, as the BC1.2 specification states that this is the max current
draw possible when in the connected and unconfigured state.

Wesley Cheng (3):
  usb: dwc3: gadget: Introduce a DWC3 VBUS draw callback
  usb: gadget: composite: Split composite reset and disconnect
  usb: gadget: configfs: Add a specific configFS reset callback

 drivers/usb/dwc3/gadget.c      | 11 +++++++++++
 drivers/usb/gadget/composite.c | 21 +++++++++++++++++++--
 drivers/usb/gadget/configfs.c  | 24 +++++++++++++++++++++++-
 include/linux/usb/composite.h  |  2 ++
 4 files changed, 55 insertions(+), 3 deletions(-)

-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

[PATCH 1/3] usb: dwc3: gadget: Introduce a DWC3 VBUS draw callback

[Wesley Cheng]

Some devices support charging while in device mode.  In these situations,
the USB gadget will notify the DWC3 gadget driver to modify the current
based on the enumeration and device state.  The usb_phy_set_power() API
will allow external charger entities to adjust the charge current through
the notifier block.

Signed-off-by: Wesley Cheng <wcheng@codeaurora.org>
---
 drivers/usb/dwc3/gadget.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index c145da1d8ba5..69122f66978e 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -2387,6 +2387,16 @@ static void dwc3_gadget_set_speed(struct usb_gadget *g,
 	spin_unlock_irqrestore(&dwc->lock, flags);
 }
 
+static int dwc3_gadget_vbus_draw(struct usb_gadget *g, unsigned int mA)
+{
+	struct dwc3		*dwc = gadget_to_dwc(g);
+
+	if (dwc->usb2_phy)
+		return usb_phy_set_power(dwc->usb2_phy, mA);
+
+	return 0;
+}
+
 static const struct usb_gadget_ops dwc3_gadget_ops = {
 	.get_frame		= dwc3_gadget_get_frame,
 	.wakeup			= dwc3_gadget_wakeup,
@@ -2396,6 +2406,7 @@ static const struct usb_gadget_ops dwc3_gadget_ops = {
 	.udc_stop		= dwc3_gadget_stop,
 	.udc_set_speed		= dwc3_gadget_set_speed,
 	.get_config_params	= dwc3_gadget_config_params,
+	.vbus_draw		= dwc3_gadget_vbus_draw,
 };
 
 /* -------------------------------------------------------------------------- */
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

[PATCH 2/3] usb: gadget: composite: Split composite reset and disconnect

[Wesley Cheng]

Add a specific composite reset API to differentiate between disconnect and
reset events.  This is needed for adjusting the current draw accordingly
based on the USB battery charging specification.  The device is only allowed
to draw the 500/900 mA (HS/SS) while in the CONFIGURED state, and only 100 mA
in the connected and UNCONFIGURED state.

Signed-off-by: Wesley Cheng <wcheng@codeaurora.org>
---
 drivers/usb/gadget/composite.c | 21 +++++++++++++++++++--
 include/linux/usb/composite.h  |  2 ++
 2 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
index 05b176c82cc5..a41f7fe4b518 100644
--- a/drivers/usb/gadget/composite.c
+++ b/drivers/usb/gadget/composite.c
@@ -2036,7 +2036,7 @@ composite_setup(struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
 	return value;
 }
 
-void composite_disconnect(struct usb_gadget *gadget)
+static void __composite_disconnect(struct usb_gadget *gadget)
 {
 	struct usb_composite_dev	*cdev = get_gadget_data(gadget);
 	unsigned long			flags;
@@ -2053,6 +2053,23 @@ void composite_disconnect(struct usb_gadget *gadget)
 	spin_unlock_irqrestore(&cdev->lock, flags);
 }
 
+void composite_disconnect(struct usb_gadget *gadget)
+{
+	usb_gadget_vbus_draw(gadget, 0);
+	__composite_disconnect(gadget);
+}
+
+void composite_reset(struct usb_gadget *gadget)
+{
+	/*
+	 * Section 1.4.13 Standard Downstream Port of the USB battery charging
+	 * specification v1.2 states that a device connected on a SDP shall only
+	 * draw at max 100mA while in a connected, but unconfigured state.
+	 */
+	usb_gadget_vbus_draw(gadget, 100);
+	__composite_disconnect(gadget);
+}
+
 /*-------------------------------------------------------------------------*/
 
 static ssize_t suspended_show(struct device *dev, struct device_attribute *attr,
@@ -2373,7 +2390,7 @@ static const struct usb_gadget_driver composite_driver_template = {
 	.unbind		= composite_unbind,
 
 	.setup		= composite_setup,
-	.reset		= composite_disconnect,
+	.reset		= composite_reset,
 	.disconnect	= composite_disconnect,
 
 	.suspend	= composite_suspend,
diff --git a/include/linux/usb/composite.h b/include/linux/usb/composite.h
index 2040696d75b6..0d8a71471512 100644
--- a/include/linux/usb/composite.h
+++ b/include/linux/usb/composite.h
@@ -525,6 +525,8 @@ extern struct usb_string *usb_gstrings_attach(struct usb_composite_dev *cdev,
 extern int usb_string_ids_n(struct usb_composite_dev *c, unsigned n);
 
 extern void composite_disconnect(struct usb_gadget *gadget);
+extern void composite_reset(struct usb_gadget *gadget);
+
 extern int composite_setup(struct usb_gadget *gadget,
 		const struct usb_ctrlrequest *ctrl);
 extern void composite_suspend(struct usb_gadget *gadget);
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

[PATCH 3/3] usb: gadget: configfs: Add a specific configFS reset callback

[Wesley Cheng]

In order for configFS based USB gadgets to set the proper charge current
for bus reset scenarios, expose a separate reset callback to set the
current to 100mA based on the USB battery charging specification.

Signed-off-by: Wesley Cheng <wcheng@codeaurora.org>
---
 drivers/usb/gadget/configfs.c | 24 +++++++++++++++++++++++-
 1 file changed, 23 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/gadget/configfs.c b/drivers/usb/gadget/configfs.c
index 56051bb97349..80ca7ff2fb97 100644
--- a/drivers/usb/gadget/configfs.c
+++ b/drivers/usb/gadget/configfs.c
@@ -1481,6 +1481,28 @@ static void configfs_composite_disconnect(struct usb_gadget *gadget)
 	spin_unlock_irqrestore(&gi->spinlock, flags);
 }
 
+static void configfs_composite_reset(struct usb_gadget *gadget)
+{
+	struct usb_composite_dev *cdev;
+	struct gadget_info *gi;
+	unsigned long flags;
+
+	cdev = get_gadget_data(gadget);
+	if (!cdev)
+		return;
+
+	gi = container_of(cdev, struct gadget_info, cdev);
+	spin_lock_irqsave(&gi->spinlock, flags);
+	cdev = get_gadget_data(gadget);
+	if (!cdev || gi->unbind) {
+		spin_unlock_irqrestore(&gi->spinlock, flags);
+		return;
+	}
+
+	composite_reset(gadget);
+	spin_unlock_irqrestore(&gi->spinlock, flags);
+}
+
 static void configfs_composite_suspend(struct usb_gadget *gadget)
 {
 	struct usb_composite_dev *cdev;
@@ -1530,7 +1552,7 @@ static const struct usb_gadget_driver configfs_driver_template = {
 	.unbind         = configfs_composite_unbind,
 
 	.setup          = configfs_composite_setup,
-	.reset          = configfs_composite_disconnect,
+	.reset          = configfs_composite_reset,
 	.disconnect     = configfs_composite_disconnect,
 
 	.suspend	= configfs_composite_suspend,
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

Re: [PATCH 1/3] usb: dwc3: gadget: Introduce a DWC3 VBUS draw callback

[Peter Chen]

On 20-11-14 00:12:45, Wesley Cheng wrote:
> Some devices support charging while in device mode.  In these situations,
> the USB gadget will notify the DWC3 gadget driver to modify the current
> based on the enumeration and device state.  The usb_phy_set_power() API
> will allow external charger entities to adjust the charge current through
> the notifier block.
> 
> Signed-off-by: Wesley Cheng <wcheng@codeaurora.org>
> ---
>  drivers/usb/dwc3/gadget.c | 11 +++++++++++
>  1 file changed, 11 insertions(+)
> 
> diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
> index c145da1d8ba5..69122f66978e 100644
> --- a/drivers/usb/dwc3/gadget.c
> +++ b/drivers/usb/dwc3/gadget.c
> @@ -2387,6 +2387,16 @@ static void dwc3_gadget_set_speed(struct usb_gadget *g,
>  	spin_unlock_irqrestore(&dwc->lock, flags);
>  }
>  
> +static int dwc3_gadget_vbus_draw(struct usb_gadget *g, unsigned int mA)
> +{
> +	struct dwc3		*dwc = gadget_to_dwc(g);
> +
> +	if (dwc->usb2_phy)
> +		return usb_phy_set_power(dwc->usb2_phy, mA);
> +
> +	return 0;
> +}
> +
>  static const struct usb_gadget_ops dwc3_gadget_ops = {
>  	.get_frame		= dwc3_gadget_get_frame,
>  	.wakeup			= dwc3_gadget_wakeup,
> @@ -2396,6 +2406,7 @@ static const struct usb_gadget_ops dwc3_gadget_ops = {
>  	.udc_stop		= dwc3_gadget_stop,
>  	.udc_set_speed		= dwc3_gadget_set_speed,
>  	.get_config_params	= dwc3_gadget_config_params,
> +	.vbus_draw		= dwc3_gadget_vbus_draw,
>  };
>  

Reviewed-by: Peter Chen <peter.chen@nxp.com>

-- 

Thanks,
Peter Chen

Re: [PATCH 2/3] usb: gadget: composite: Split composite reset and disconnect

[Peter Chen]

On 20-11-14 00:12:46, Wesley Cheng wrote:
> Add a specific composite reset API to differentiate between disconnect and
> reset events.  This is needed for adjusting the current draw accordingly
> based on the USB battery charging specification.  The device is only allowed
> to draw the 500/900 mA (HS/SS) while in the CONFIGURED state, and only 100 mA
> in the connected and UNCONFIGURED state.
> 
> Signed-off-by: Wesley Cheng <wcheng@codeaurora.org>

Reviewed-by: Peter Chen <peter.chen@nxp.com>

Peter
> ---
>  drivers/usb/gadget/composite.c | 21 +++++++++++++++++++--
>  include/linux/usb/composite.h  |  2 ++
>  2 files changed, 21 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
> index 05b176c82cc5..a41f7fe4b518 100644
> --- a/drivers/usb/gadget/composite.c
> +++ b/drivers/usb/gadget/composite.c
> @@ -2036,7 +2036,7 @@ composite_setup(struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
>  	return value;
>  }
>  
> -void composite_disconnect(struct usb_gadget *gadget)
> +static void __composite_disconnect(struct usb_gadget *gadget)
>  {
>  	struct usb_composite_dev	*cdev = get_gadget_data(gadget);
>  	unsigned long			flags;
> @@ -2053,6 +2053,23 @@ void composite_disconnect(struct usb_gadget *gadget)
>  	spin_unlock_irqrestore(&cdev->lock, flags);
>  }
>  
> +void composite_disconnect(struct usb_gadget *gadget)
> +{
> +	usb_gadget_vbus_draw(gadget, 0);
> +	__composite_disconnect(gadget);
> +}
> +
> +void composite_reset(struct usb_gadget *gadget)
> +{
> +	/*
> +	 * Section 1.4.13 Standard Downstream Port of the USB battery charging
> +	 * specification v1.2 states that a device connected on a SDP shall only
> +	 * draw at max 100mA while in a connected, but unconfigured state.
> +	 */
> +	usb_gadget_vbus_draw(gadget, 100);
> +	__composite_disconnect(gadget);
> +}
> +
>  /*-------------------------------------------------------------------------*/
>  
>  static ssize_t suspended_show(struct device *dev, struct device_attribute *attr,
> @@ -2373,7 +2390,7 @@ static const struct usb_gadget_driver composite_driver_template = {
>  	.unbind		= composite_unbind,
>  
>  	.setup		= composite_setup,
> -	.reset		= composite_disconnect,
> +	.reset		= composite_reset,
>  	.disconnect	= composite_disconnect,
>  
>  	.suspend	= composite_suspend,
> diff --git a/include/linux/usb/composite.h b/include/linux/usb/composite.h
> index 2040696d75b6..0d8a71471512 100644
> --- a/include/linux/usb/composite.h
> +++ b/include/linux/usb/composite.h
> @@ -525,6 +525,8 @@ extern struct usb_string *usb_gstrings_attach(struct usb_composite_dev *cdev,
>  extern int usb_string_ids_n(struct usb_composite_dev *c, unsigned n);
>  
>  extern void composite_disconnect(struct usb_gadget *gadget);
> +extern void composite_reset(struct usb_gadget *gadget);
> +
>  extern int composite_setup(struct usb_gadget *gadget,
>  		const struct usb_ctrlrequest *ctrl);
>  extern void composite_suspend(struct usb_gadget *gadget);
> -- 
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> a Linux Foundation Collaborative Project
> 

-- 

Thanks,
Peter Chen

Re: [PATCH 3/3] usb: gadget: configfs: Add a specific configFS reset callback

[Peter Chen]

On 20-11-14 00:12:47, Wesley Cheng wrote:
> In order for configFS based USB gadgets to set the proper charge current
> for bus reset scenarios, expose a separate reset callback to set the
> current to 100mA based on the USB battery charging specification.
> 
> Signed-off-by: Wesley Cheng <wcheng@codeaurora.org>

Reviewed-by: Peter Chen <peter.chen@nxp.com>

> ---
>  drivers/usb/gadget/configfs.c | 24 +++++++++++++++++++++++-
>  1 file changed, 23 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/gadget/configfs.c b/drivers/usb/gadget/configfs.c
> index 56051bb97349..80ca7ff2fb97 100644
> --- a/drivers/usb/gadget/configfs.c
> +++ b/drivers/usb/gadget/configfs.c
> @@ -1481,6 +1481,28 @@ static void configfs_composite_disconnect(struct usb_gadget *gadget)
>  	spin_unlock_irqrestore(&gi->spinlock, flags);
>  }
>  
> +static void configfs_composite_reset(struct usb_gadget *gadget)
> +{
> +	struct usb_composite_dev *cdev;
> +	struct gadget_info *gi;
> +	unsigned long flags;
> +
> +	cdev = get_gadget_data(gadget);
> +	if (!cdev)
> +		return;
> +
> +	gi = container_of(cdev, struct gadget_info, cdev);
> +	spin_lock_irqsave(&gi->spinlock, flags);
> +	cdev = get_gadget_data(gadget);
> +	if (!cdev || gi->unbind) {
> +		spin_unlock_irqrestore(&gi->spinlock, flags);
> +		return;
> +	}
> +
> +	composite_reset(gadget);
> +	spin_unlock_irqrestore(&gi->spinlock, flags);
> +}
> +
>  static void configfs_composite_suspend(struct usb_gadget *gadget)
>  {
>  	struct usb_composite_dev *cdev;
> @@ -1530,7 +1552,7 @@ static const struct usb_gadget_driver configfs_driver_template = {
>  	.unbind         = configfs_composite_unbind,
>  
>  	.setup          = configfs_composite_setup,
> -	.reset          = configfs_composite_disconnect,
> +	.reset          = configfs_composite_reset,
>  	.disconnect     = configfs_composite_disconnect,
>  
>  	.suspend	= configfs_composite_suspend,
> -- 
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> a Linux Foundation Collaborative Project
> 

-- 

Thanks,
Peter Chen

[PATCH 1/3] usb: dwc3: gadget: Introduce a DWC3 VBUS draw callback

[Wesley Cheng]

Some devices support charging while in device mode.  In these situations,
the USB gadget will notify the DWC3 gadget driver to modify the current
based on the enumeration and device state.  The usb_phy_set_power() API
will allow external charger entities to adjust the charge current through
the notifier block.

Reviewed-by: Peter Chen <peter.chen@nxp.com>
Signed-off-by: Wesley Cheng <wcheng@codeaurora.org>
---
 drivers/usb/dwc3/gadget.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index c145da1d8ba5..69122f66978e 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -2387,6 +2387,16 @@ static void dwc3_gadget_set_speed(struct usb_gadget *g,
 	spin_unlock_irqrestore(&dwc->lock, flags);
 }
 
+static int dwc3_gadget_vbus_draw(struct usb_gadget *g, unsigned int mA)
+{
+	struct dwc3		*dwc = gadget_to_dwc(g);
+
+	if (dwc->usb2_phy)
+		return usb_phy_set_power(dwc->usb2_phy, mA);
+
+	return 0;
+}
+
 static const struct usb_gadget_ops dwc3_gadget_ops = {
 	.get_frame		= dwc3_gadget_get_frame,
 	.wakeup			= dwc3_gadget_wakeup,
@@ -2396,6 +2406,7 @@ static const struct usb_gadget_ops dwc3_gadget_ops = {
 	.udc_stop		= dwc3_gadget_stop,
 	.udc_set_speed		= dwc3_gadget_set_speed,
 	.get_config_params	= dwc3_gadget_config_params,
+	.vbus_draw		= dwc3_gadget_vbus_draw,
 };
 
 /* -------------------------------------------------------------------------- */
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project