[coreboot-gerrit] Patch set updated for coreboot: google/gru: Add USB 2.0 PHY tuning for Kevin

[Martin Roth (martinroth@google.com)]

Martin Roth (martinroth at google.com) just uploaded a new patch set to gerrit, which you can find at https://review.coreboot.org/16265

-gerrit

commit 7ea67b85fe321cef73fee82aa896ba5cd32b7c55
Author: Julius Werner <jwerner at chromium.org>
Date:   Mon Aug 15 17:58:05 2016 -0700

    google/gru: Add USB 2.0 PHY tuning for Kevin
    
    This patch sets some magic number in magic undocumented registers that
    are rumored to make USB 2.0 signal integrity better on Kevin. I don't
    see any difference (unfortunately it doesn't solve the problems with
    long cables on my board), but I guess it doesn't hurt either way.
    
    BRANCH=None
    BUG=chrome-os-partner:56108,chrome-os-partner:54788
    TEST=Booted Kevin with USB connected through Servo. Seems to have
    roughly the same failure rate as before.
    
    Change-Id: If31fb49f1ed7218b50f24e251e54c9400db72720
    Signed-off-by: Martin Roth <martinroth at chromium.org>
    Original-Commit-Id: 0c5c8f0f80ea1ebb042bcb91506a6100833e7e84
    Original-Change-Id: Ifbd47bf6adb63a2ca5371c0b05c5ec27a0fe3195
    Original-Signed-off-by: Julius Werner <jwerner at chromium.org>
    Original-Reviewed-on: https://chromium-review.googlesource.com/370900
    Original-Reviewed-by: Guenter Roeck <groeck at chromium.org>
    Original-Reviewed-by: David Schneider <dnschneid at chromium.org>
---
 src/mainboard/google/gru/mainboard.c      | 13 +++++++++++++
 src/soc/rockchip/rk3399/include/soc/grf.h |  2 +-
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/src/mainboard/google/gru/mainboard.c b/src/mainboard/google/gru/mainboard.c
index 8a6cda2..7fd8f14 100644
--- a/src/mainboard/google/gru/mainboard.c
+++ b/src/mainboard/google/gru/mainboard.c
@@ -158,6 +158,19 @@ static void configure_display(void)
 
 static void setup_usb(void)
 {
+	/*
+	 * A few magic PHY tuning values that improve eye diagram amplitude
+	 * and make it extra sure we get reliable communication in firmware.
+	 */
+
+	 /* Set max ODT compensation voltage and current tuning reference. */
+	write32(&rk3399_grf->usbphy0_ctrl[3], 0x0fff02e3);
+	write32(&rk3399_grf->usbphy1_ctrl[3], 0x0fff02e3);
+
+	/* Set max pre-emphasis level, only on Kevin PHY0. */
+	if (IS_ENABLED(CONFIG_BOARD_GOOGLE_KEVIN))
+		write32(&rk3399_grf->usbphy0_ctrl[12], 0xffff00a7);
+
 	setup_usb_otg0();
 	setup_usb_otg1();
 }
diff --git a/src/soc/rockchip/rk3399/include/soc/grf.h b/src/soc/rockchip/rk3399/include/soc/grf.h
index d76b827..c1fd690 100644
--- a/src/soc/rockchip/rk3399/include/soc/grf.h
+++ b/src/soc/rockchip/rk3399/include/soc/grf.h
@@ -73,7 +73,7 @@ struct rk3399_grf_regs {
 	u32 reserved11[3];
 	u32 usbphy0_ctrl[26];
 	u32 reserved12[6];
-	u32 usbphy1[26];
+	u32 usbphy1_ctrl[26];
 	u32 reserved13[0x72f];
 	u32 soc_con9;
 	u32 reserved14[0x0a];