Ronald G. Minnich (rminnich@gmail.com) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/3109
-gerrit
commit 12c6b4885b031a1f1fbc6a22b0ce494316a9c6f7 Author: David Hendricks dhendrix@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@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 1cd84e8..54d13d3 100644 --- a/src/mainboard/google/snow/ramstage.c +++ b/src/mainboard/google/snow/ramstage.c @@ -198,6 +198,16 @@ static struct video_info snow_dp_video_info = { #define EXYNOS5250_DP1_BASE 0x145b0000 #define SNOW_MAX_DP_TRIES 5
+/* + * This function disables 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) { @@ -215,6 +225,9 @@ static void mainboard_init(device_t dev) /* Clock Gating all the unused IP's to save power */ clock_gate();
+ /* Disable USB3.0 PLL to save 250mW of power */ + disable_usb30_pll(); + snow_lcd_vdd(); do { udelay(50);