t132: Add support for tpm i2c

Iniitialize I2C bus required for TPM operation. Problem observed was that if
frequency is raised above 20KHz, TPM starts responding with NAKs either for
address or for data. Need to look into that.

BUG=None
BRANCH=None
TEST=Compiles successfully and TPM success messages seen while booting.

Change-Id: I9e1b4958d2ec010e31179df12a099277e6ce09e0
Signed-off-by: Furquan Shaikh <furquan@google.com>
Reviewed-on: https://chromium-review.googlesource.com/210001
Tested-by: Furquan Shaikh <furquan@chromium.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Commit-Queue: Aaron Durbin <adurbin@chromium.org>

src/mainboard/google/rush/romstage.c

@@ -19,6 +19,38 @@
 
 #include <soc/romstage.h>
 
+#include <soc/addressmap.h>
+#include <soc/clock.h>
+#include <soc/nvidia/tegra/i2c.h>
+#include <soc/nvidia/tegra132/pinmux.h>
+#include <soc/nvidia/tegra132/gpio.h>
+
+static struct clk_rst_ctlr *clk_rst = (void *)TEGRA_CLK_RST_BASE;
+
+static void configure_tpm_i2c_bus(void)
+{
+	clock_configure_i2c_scl_freq(i2c3, PLLP, 19);
+
+	i2c_init(2);
+}
+
+void mainboard_init_tpm_i2c(void)
+{
+	clock_enable_clear_reset(0, 0, CLK_U_I2C3, 0, 0, 0);
+
+	gpio_output(GPIO(I5), 1);
+
+	// I2C3 (cam) clock.
+	pinmux_set_config(PINMUX_CAM_I2C_SCL_INDEX,
+			  PINMUX_CAM_I2C_SCL_FUNC_I2C3 | PINMUX_INPUT_ENABLE);
+	// I2C3 (cam) data.
+	pinmux_set_config(PINMUX_CAM_I2C_SDA_INDEX,
+			  PINMUX_CAM_I2C_SDA_FUNC_I2C3 | PINMUX_INPUT_ENABLE);
+
+
+	configure_tpm_i2c_bus();
+}
+
 void mainboard_configure_pmc(void)
 {
 }

src/soc/nvidia/tegra132/include/soc/romstage.h

@@ -22,5 +22,6 @@
 
 void mainboard_configure_pmc(void);
 void mainboard_enable_vdd_cpu(void);
+void mainboard_init_tpm_i2c(void);
 
 #endif /* __SOC_NVIDIA_TEGRA132_SOC_ROMSTAGE_H__ */

src/soc/nvidia/tegra132/romstage.c

@@ -30,6 +30,7 @@
 #include "ccplex.h"
 
 #include <soc/clock.h>
+#include <soc/romstage.h>
 
 void romstage(void);
 
@@ -85,6 +86,8 @@ void romstage(void)
 	ccplex_load_mts();
 	printk(BIOS_INFO, "T132 romstage: MTS loading done\n");
 
+	mainboard_init_tpm_i2c();
+
 	entry = load_ramstage();
 
 	if (entry == NULL) {