usb gadget: USB_GADGET_VBUS_DRAW Kconfig option

Offer a "how much VBUS power to request" configuration option
for USB gadgets that aren't using board-specific customization
of their gadget or (composite) configuration drivers.

Also remove a couple pointless "depends on USB_GADGET" bits
from the Kconfig text; booleans inside an "if USB_GADGET" will
already have that dependency.

Based on a patch from Justin Clacherty.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Justin Clacherty <justin@redfish-group.com>
Tested-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/gadget/Kconfig

@@ -45,7 +45,7 @@ if USB_GADGET
 
 config USB_GADGET_DEBUG
 	boolean "Debugging messages (DEVELOPMENT)"
-	depends on USB_GADGET && DEBUG_KERNEL
+	depends on DEBUG_KERNEL
 	help
 	   Many controller and gadget drivers will print some debugging
 	   messages if you use this option to ask for those messages.
@@ -59,7 +59,7 @@ config USB_GADGET_DEBUG
 
 config USB_GADGET_DEBUG_FILES
 	boolean "Debugging information files (DEVELOPMENT)"
-	depends on USB_GADGET && PROC_FS
+	depends on PROC_FS
 	help
 	   Some of the drivers in the "gadget" framework can expose
 	   debugging information in files such as /proc/driver/udc
@@ -70,7 +70,7 @@ config USB_GADGET_DEBUG_FILES
 
 config USB_GADGET_DEBUG_FS
 	boolean "Debugging information files in debugfs (DEVELOPMENT)"
-	depends on USB_GADGET && DEBUG_FS
+	depends on DEBUG_FS
 	help
 	   Some of the drivers in the "gadget" framework can expose
 	   debugging information in files under /sys/kernel/debug/.
@@ -79,6 +79,23 @@ config USB_GADGET_DEBUG_FS
 	   Enable these files by choosing "Y" here.  If in doubt, or
 	   to conserve kernel memory, say "N".
 
+config USB_GADGET_VBUS_DRAW
+	int "Maximum VBUS Power usage (2-500 mA)"
+	range 2 500
+	default 2
+	help
+	   Some devices need to draw power from USB when they are
+	   configured, perhaps to operate circuitry or to recharge
+	   batteries.  This is in addition to any local power supply,
+	   such as an AC adapter or batteries.
+
+	   Enter the maximum power your device draws through USB, in
+	   milliAmperes.  The permitted range of values is 2 - 500 mA;
+	   0 mA would be legal, but can make some hosts misbehave.
+
+	   This value will be used except for system-specific gadget
+	   drivers that have more specific information.
+
 config	USB_GADGET_SELECTED
 	boolean
 

drivers/usb/gadget/cdc2.c

@@ -155,7 +155,6 @@ static struct usb_configuration cdc_config_driver = {
 	.bConfigurationValue	= 1,
 	/* .iConfiguration = DYNAMIC */
 	.bmAttributes		= USB_CONFIG_ATT_SELFPOWER,
-	.bMaxPower		= 1,	/* 2 mA, minimal */
 };
 
 /*-------------------------------------------------------------------------*/

drivers/usb/gadget/composite.c

@@ -245,7 +245,7 @@ static int config_buf(struct usb_configuration *config,
 	c->bConfigurationValue = config->bConfigurationValue;
 	c->iConfiguration = config->iConfiguration;
 	c->bmAttributes = USB_CONFIG_ATT_ONE | config->bmAttributes;
-	c->bMaxPower = config->bMaxPower;
+	c->bMaxPower = config->bMaxPower ? : (CONFIG_USB_GADGET_VBUS_DRAW / 2);
 
 	/* There may be e.g. OTG descriptors */
 	if (config->descriptors) {
@@ -432,7 +432,7 @@ static int set_config(struct usb_composite_dev *cdev,
 	}
 
 	/* when we return, be sure our power usage is valid */
-	power = 2 * c->bMaxPower;
+	power = c->bMaxPower ? (2 * c->bMaxPower) : CONFIG_USB_GADGET_VBUS_DRAW;
 done:
 	usb_gadget_vbus_draw(gadget, power);
 	return result;

drivers/usb/gadget/ether.c

@@ -242,7 +242,6 @@ static struct usb_configuration rndis_config_driver = {
 	.bConfigurationValue	= 2,
 	/* .iConfiguration = DYNAMIC */
 	.bmAttributes		= USB_CONFIG_ATT_SELFPOWER,
-	.bMaxPower		= 1,	/* 2 mA, minimal */
 };
 
 /*-------------------------------------------------------------------------*/
@@ -271,7 +270,6 @@ static struct usb_configuration eth_config_driver = {
 	.bConfigurationValue	= 1,
 	/* .iConfiguration = DYNAMIC */
 	.bmAttributes		= USB_CONFIG_ATT_SELFPOWER,
-	.bMaxPower		= 1,	/* 2 mA, minimal */
 };
 
 /*-------------------------------------------------------------------------*/

drivers/usb/gadget/f_loopback.c

@@ -352,7 +352,6 @@ static struct usb_configuration loopback_driver = {
 	.bind		= loopback_bind_config,
 	.bConfigurationValue = 2,
 	.bmAttributes	= USB_CONFIG_ATT_SELFPOWER,
-	.bMaxPower	= 1,	/* 2 mA, minimal */
 	/* .iConfiguration = DYNAMIC */
 };
 

drivers/usb/gadget/f_sourcesink.c

@@ -552,7 +552,6 @@ static struct usb_configuration sourcesink_driver = {
 	.setup		= sourcesink_setup,
 	.bConfigurationValue = 3,
 	.bmAttributes	= USB_CONFIG_ATT_SELFPOWER,
-	.bMaxPower	= 1,	/* 2 mA, minimal */
 	/* .iConfiguration = DYNAMIC */
 };
 

drivers/usb/gadget/file_storage.c

@@ -851,7 +851,7 @@ config_desc = {
 	.bConfigurationValue =	CONFIG_VALUE,
 	.iConfiguration =	STRING_CONFIG,
 	.bmAttributes =		USB_CONFIG_ATT_ONE | USB_CONFIG_ATT_SELFPOWER,
-	.bMaxPower =		1,	// self-powered
+	.bMaxPower =		CONFIG_USB_GADGET_VBUS_DRAW / 2,
 };
 
 static struct usb_otg_descriptor

drivers/usb/gadget/gmidi.c

@@ -222,7 +222,7 @@ static struct usb_config_descriptor config_desc = {
 	 * power properties of the device. Is it selfpowered?
 	 */
 	.bmAttributes =		USB_CONFIG_ATT_ONE,
-	.bMaxPower =		1,
+	.bMaxPower =		CONFIG_USB_GADGET_VBUS_DRAW / 2,
 };
 
 /* B.3.1  Standard AC Interface Descriptor */

drivers/usb/gadget/printer.c

@@ -252,7 +252,7 @@ static struct usb_config_descriptor config_desc = {
 	.bConfigurationValue =	DEV_CONFIG_VALUE,
 	.iConfiguration =	0,
 	.bmAttributes =		USB_CONFIG_ATT_ONE | USB_CONFIG_ATT_SELFPOWER,
-	.bMaxPower =		1	/* Self-Powered */
+	.bMaxPower =		CONFIG_USB_GADGET_VBUS_DRAW / 2,
 };
 
 static struct usb_interface_descriptor intf_desc = {
@@ -1476,7 +1476,6 @@ printer_bind(struct usb_gadget *gadget)
 	if (gadget->is_otg) {
 		otg_desc.bmAttributes |= USB_OTG_HNP,
 		config_desc.bmAttributes |= USB_CONFIG_ATT_WAKEUP;
-		config_desc.bMaxPower = 4;
 	}
 
 	spin_lock_init(&dev->lock);

drivers/usb/gadget/serial.c

@@ -159,7 +159,6 @@ static struct usb_configuration serial_config_driver = {
 	/* .bConfigurationValue = f(use_acm) */
 	/* .iConfiguration = DYNAMIC */
 	.bmAttributes	= USB_CONFIG_ATT_SELFPOWER,
-	.bMaxPower	= 1,	/* 2 mA, minimal */
 };
 
 static int __init gs_bind(struct usb_composite_dev *cdev)