ARM: omap3evm: enable VBUS switch for EHCI tranceiver

This was chosen by following the trace on the schematic from component U131
and U134 to the CPEN pin on the USB3320 device.

TWL4030.GPIO2-...->(T2_GPIO2_3V3)U131-..>nUSB2_EN-..>U134-..>EXP_nUSB2_1V8
which starts EHCI tranceiver USB3320.

This will set TWL4030.GPIO2 as output pin to drive EHCI tranceiver.
Signed-off-by: Zumeng Chen <zumeng.chen@windriver.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/mach-omap2/board-omap3evm.c

@@ -360,6 +360,17 @@ static int omap3evm_twl_gpio_setup(struct device *dev,
 
 	platform_device_register(&leds_gpio);
 
+	/* Enable VBUS switch by setting TWL4030.GPIO2DIR as output
+	 * for starting USB tranceiver
+	 */
+	if (get_omap3_evm_rev() >= OMAP3EVM_BOARD_GEN_2) {
+		u8 val;
+
+		twl_i2c_read_u8(TWL4030_MODULE_GPIO, &val, REG_GPIODATADIR1);
+		val |= 0x04; /* TWL4030.GPIO2DIR BIT at GPIODATADIR1(0x9B) */
+		twl_i2c_write_u8(TWL4030_MODULE_GPIO, val, REG_GPIODATADIR1);
+	}
+
 	return 0;
 }