usb: misc: usb3503: Adding device tree entry 'disabled-ports'

This patch is to add a property 'disabled-ports' representing the unused port
of USB3503. USB3503 can support up to 3 USB host port and each ports can be
controlled to be enabled or disabled. Do not describe this property if all
ports must be enabled.

You can represent the ports to disable in the device tree.

usb3503@08{
...
disabled-ports = <2 3>;
...
};

Signed-off-by: Dongjin Kim <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

Documentation/devicetree/bindings/usb/usb3503.txt

···
 - compatible: Should be "smsc,usb3503".
 - reg: Specifies the i2c slave address, it should be 0x08.
 - connect-gpios: Should specify GPIO for connect.
+- disabled-ports: Should specify the ports unused.
+	'1' or '2' or '3' are availe for this property to describe the port
+	number. 1~3 property values are possible to be desribed.
+	Do not describe this property if all ports have to be enabled.
 - intn-gpios: Should specify GPIO for interrupt.
 - reset-gpios: Should specify GPIO for reset.
 - initial-mode: Should specify initial mode.
···
 		compatible = "smsc,usb3503";
 		reg = <0x08>;
 		connect-gpios = <&gpx3 0 1>;
+		disabled-ports = <2 3>;
 		intn-gpios = <&gpx3 4 1>;
 		reset-gpios = <&gpx3 5 1>;
 		initial-mode = <1>;

drivers/usb/misc/usb3503.c

···
 	struct usb3503 *hub;
 	int err = -ENOMEM;
 	u32 mode = USB3503_MODE_UNKNOWN;
+	const u32 *property;
+	int len;
 
 	hub = kzalloc(sizeof(struct usb3503), GFP_KERNEL);
 	if (!hub) {
···
 		hub->gpio_reset		= pdata->gpio_reset;
 		hub->mode		= pdata->initial_mode;
 	} else if (np) {
+		hub->port_off_mask = 0;
+
+		property = of_get_property(np, "disabled-ports", &len);
+		if (property && (len / sizeof(u32)) > 0) {
+			int i;
+			for (i = 0; i < len / sizeof(u32); i++) {
+				u32 port = be32_to_cpu(property[i]);
+				if ((1 <= port) && (port <= 3))
+					hub->port_off_mask |= (1 << port);
+			}
+		}
+
 		hub->gpio_intn	= of_get_named_gpio(np, "connect-gpios", 0);
 		if (hub->gpio_intn == -EPROBE_DEFER)
 			return -EPROBE_DEFER;