nyan: big: Set the i2c controller frequencies appropriately.

These had been set to something fairly random which results in a very slow
clock on the bus itself. The new settings take into consideration the speed
the devices on the bus can run at. The TPM can't seem to handle speeds above
40KHz, but some documentation suggests that it should be able to handle up to
at least 100KHz.

BUG=chrome-os-partner:25467
TEST=Built and booted on nyan rev1. Built for big.
BRANCH=None

Original-Change-Id: Iee98957c7e492c7dd08b071aeef3cce75c4a9e56
Original-Signed-off-by: Gabe Black <gabeblack@google.com>
Original-Reviewed-on: https://chromium-review.googlesource.com/189015
Original-Reviewed-by: Julius Werner <jwerner@chromium.org>
Original-Tested-by: Gabe Black <gabeblack@chromium.org>
Original-Reviewed-by: David Hendricks <dhendrix@chromium.org>
Original-Commit-Queue: Gabe Black <gabeblack@chromium.org>
(cherry picked from commit afca97a29aeb99d3899b713d0e57a3b3214f0d96)
Signed-off-by: Marc Jones <marc.jones@se-eng.com>

Change-Id: Iab0c50b2119ac322252564354c90b5cb2d255c97
Reviewed-on: http://review.coreboot.org/7418
Tested-by: build bot (Jenkins)
Reviewed-by: David Hendricks <dhendrix@chromium.org>

2 files changed, 13 insertions, 6 deletions

diff --git a/src/mainboard/google/nyan/bootblock.c b/src/mainboard/google/nyan/bootblock.c
index c168550541..2b033a6f48 100644
--- a/src/mainboard/google/nyan/bootblock.c
+++ b/src/mainboard/google/nyan/bootblock.c
@@ -40,8 +40,8 @@ static void set_clock_sources(void)
 
 	clock_configure_source(mselect, PLLP, 102000);
 
-	/* TODO: is the 1.333MHz correct? This may have always been bogus... */
-	clock_configure_source(i2c5, CLK_M, 1333);
+	/* The PMIC is on I2C5 and can run at 400 KHz. */
+	clock_configure_i2c_scl_freq(i2c5, PLLP, 400);
 
 	/* TODO: We should be able to set this to 50MHz, but that did not seem
 	 * reliable. */
diff --git a/src/mainboard/google/nyan/mainboard.c b/src/mainboard/google/nyan/mainboard.c
index 205051a09e..35ded72e0a 100644
--- a/src/mainboard/google/nyan/mainboard.c
+++ b/src/mainboard/google/nyan/mainboard.c
@@ -34,10 +34,17 @@ static struct clk_rst_ctlr *clk_rst = (void *)TEGRA_CLK_RST_BASE;
 
 static void set_clock_sources(void)
 {
-	clock_configure_source(i2c1, CLK_M, 1333);
-	clock_configure_source(i2c2, CLK_M, 1333);
-	clock_configure_source(i2c3, CLK_M, 1333);
-	clock_configure_source(i2c4, CLK_M, 1333);
+	/*
+	 * The max98090 codec and the temperature sensor are on I2C1. These
+	 * can both run at 400 KHz, but the kernel sets the bus to 100 KHz.
+	 */
+	clock_configure_i2c_scl_freq(i2c1, PLLP, 100);
+	/*
+	 * The TPM is on I2C3 and can theoretically run at 400 KHz but doesn't
+	 * seem to work above around 40 KHz. It's set to run at 100 KHz in the
+	 * kernel.
+	 */
+	clock_configure_i2c_scl_freq(i2c3, PLLP, 40);
 
 	clock_configure_source(sbc1, PLLP, 5000);