[coreboot-gerrit] New patch to review for coreboot: 4bc04a6 google/snow: disable unused USB3.0 PLL to save power

[David Hendricks (dhendrix@chromium.org)]

David Hendricks (dhendrix at chromium.org) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/3109

-gerrit

commit 4bc04a601e0ea318023ae0488994d7eda3b6037b
Author: David Hendricks <dhendrix at chromium.org>
Date:   Thu Apr 18 13:46:00 2013 -0700

    google/snow: disable unused USB3.0 PLL to save power
    
    This PLL is unused and can be disabled to save about 250mW.
    
    Change-Id: I1be37304d6ea5ff78696e05ad1023ce3c57f636c
    Signed-off-by: David Hendricks <dhendrix at chromium.org>
---
 src/mainboard/google/snow/ramstage.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/src/mainboard/google/snow/ramstage.c b/src/mainboard/google/snow/ramstage.c
index 962c79b..bacf3e9 100644
--- a/src/mainboard/google/snow/ramstage.c
+++ b/src/mainboard/google/snow/ramstage.c
@@ -205,6 +205,16 @@ static struct video_info snow_dp_video_info = {
 #define EXYNOS5250_DP1_BASE	0x145b0000
 #define SNOW_MAX_DP_TRIES	5
 
+/*
+ * This functions disable the USB3.0 PLL to save power
+ */
+static void disable_usb30_pll(void)
+{
+	enum exynos5_gpio_pin usb3_pll_l = GPIO_Y11;
+
+	gpio_direction_output(usb3_pll_l, 0);
+}
+
 /* this happens after cpu_init where exynos resources are set */
 static void mainboard_init(device_t dev)
 {
@@ -217,6 +227,9 @@ static void mainboard_init(device_t dev)
 	i2c_init(TPS69050_BUS, CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE);
 	i2c_init(7, CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE);
 
+	/* Disable USB3.0 PLL to save 250mW of power */
+	disable_usb30_pll();
+
 	snow_lcd_vdd();
 	do {
 		udelay(50);