t132: bring up 64-bit denver core

The startup sequence for cpu0 is implemented while also
providing a trampoline for transitioning to 64-bit mode because
the denver cores on t132 come out of cold reset in 32-bit mode.
Mainboard callbacks are provided for providing the board-specific
bits of the bringup sequence.

BUG=chrome-os-partner:29923
BRANCH=None
TEST=Built and booted through ramstage.

Original-Change-Id: I50755fb6b06db994af8667969d8493f214a70aae
Original-Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/207263
Original-Reviewed-by: Furquan Shaikh <furquan@chromium.org>
Original-Reviewed-by: Stefan Reinauer <reinauer@google.com>
(cherry picked from commit 17f09bf4bdb43986c19067ca8fd65d4c5365a7c6)
Signed-off-by: Marc Jones <marc.jones@se-eng.com>

Change-Id: I14d99c24dd6e29a4584c8c548c4b26c92b6ade97
Reviewed-on: http://review.coreboot.org/8586
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@google.com>

7 files changed, 231 insertions, 7 deletions

diff --git a/src/soc/nvidia/tegra132/Makefile.inc b/src/soc/nvidia/tegra132/Makefile.inc
index 8c085a945a..252f1a22dd 100644
--- a/src/soc/nvidia/tegra132/Makefile.inc
+++ b/src/soc/nvidia/tegra132/Makefile.inc
@@ -27,6 +27,7 @@ romstage-y += i2c.c
 romstage-y += dma.c
 romstage-y += monotonic_timer.c
 romstage-y += romstage.c
+romstage-y += power.c
 romstage-y += sdram.c
 romstage-y += sdram_lp0.c
 romstage-y += ../tegra/gpio.c
diff --git a/src/soc/nvidia/tegra132/ccplex.c b/src/soc/nvidia/tegra132/ccplex.c
index b774630797..9f857070e0 100644
--- a/src/soc/nvidia/tegra132/ccplex.c
+++ b/src/soc/nvidia/tegra132/ccplex.c
@@ -23,11 +23,15 @@
 #include <cbfs.h>
 #include <timer.h>
 #include <soc/addressmap.h>
+#include <soc/romstage.h>
 #include "clk_rst.h"
 #include "ccplex.h"
+#include "flow.h"
 #include "mc.h"
 #include "pmc.h"
+#include "power.h"
 
+#define EVP_CPU_RESET_VECTOR (void *)(uintptr_t)(TEGRA_EVP_BASE + 0x100)
 #define CLK_RST_REGS (void *)(uintptr_t)(TEGRA_CLK_RST_BASE)
 #define PMC_REGS (void *)(uintptr_t)(TEGRA_PMC_BASE)
 #define MTS_FILE_NAME "mts"
@@ -105,3 +109,131 @@ int ccplex_load_mts(void)
 
 	return ccplex_start();
 }
+
+static void enable_cpu_clocks(void)
+{
+	struct clk_rst_ctlr * const clk_rst = CLK_RST_REGS;
+	uint32_t reg;
+
+	reg = read32(&clk_rst->clk_enb_l_set);
+	reg |= CLK_ENB_CPU;
+	write32(reg, &clk_rst->clk_enb_l_set);
+
+	reg = read32(&clk_rst->clk_enb_v_set);
+	reg |= SET_CLK_ENB_CPUG_ENABLE | SET_CLK_ENB_CPULP_ENABLE;
+	write32(reg, &clk_rst->clk_enb_v_set);
+}
+
+static void enable_cpu_power_partitions(void)
+{
+	/* Bring up fast cluster, non-CPU, CPU0, and CPU1 partitions. */
+	power_ungate_partition(POWER_PARTID_CRAIL);
+	power_ungate_partition(POWER_PARTID_C0NC);
+	power_ungate_partition(POWER_PARTID_CE0);
+	power_ungate_partition(POWER_PARTID_CE1);
+}
+
+
+static void request_ram_repair(void)
+{
+	struct flow_ctlr * const flow = (void *)(uintptr_t)TEGRA_FLOW_BASE;
+	const uint32_t req = 1 << 0;
+	const uint32_t sts = 1 << 1;
+	uint32_t reg;
+	struct mono_time t1, t2;
+
+	printk(BIOS_DEBUG, "Requesting RAM repair.\n");
+
+	reg = read32(&flow->ram_repair);
+	reg |= req;
+	write32(reg, &flow->ram_repair);
+
+	timer_monotonic_get(&t1);
+	while ((read32(&flow->ram_repair) & sts) != sts);
+	timer_monotonic_get(&t2);
+
+	printk(BIOS_DEBUG, "RAM repair complete in %ld usecs.\n",
+		mono_time_diff_microseconds(&t1, &t2));
+}
+
+void ccplex_cpu_prepare(void)
+{
+	enable_cpu_clocks();
+	enable_cpu_power_partitions();
+
+	mainboard_configure_pmc();
+	mainboard_enable_vdd_cpu();
+
+	request_ram_repair();
+}
+
+static void start_cpu0(void)
+{
+	struct clk_rst_ctlr * const clk_rst = CLK_RST_REGS;
+
+	/* Clear fast CPU partition reset. */
+	write32(CRC_RST_CPUG_CLR_NONCPU, &clk_rst->rst_cpug_cmplx_clr);
+
+	/* Clear reset of CPU0 components. */
+	write32(CRC_RST_CPUG_CLR_CPU0 |
+		CRC_RST_CPUG_CLR_DBG0 |
+		CRC_RST_CPUG_CLR_CORE0 |
+		CRC_RST_CPUG_CLR_CX0 |
+		CRC_RST_CPUG_CLR_L2 |
+		CRC_RST_CPUG_CLR_PDBG, &clk_rst->rst_cpug_cmplx_clr);
+}
+
+/*
+ * The Denver cores come up in aarch32 mode. In order to transition to
+ * 64-bit mode a write to the RMR (reset mangement register) with the
+ * AA64 bit (0) set while setting RR (reset request bit 1).
+ */
+static const uint32_t aarch32to64[] = {
+	0xe3a00003,       /* mov     r0, #3 */
+	0xee0c0f50,       /* mcr     15, 0, r0, cr12, cr0, {2} */
+};
+
+static void load_aarch64_trampoline(void *addr)
+{
+	const size_t trampoline_size = sizeof(aarch32to64);
+	const void * const trampoline = &aarch32to64[0];
+
+	/* Copy trampoline into ram. */
+	memcpy(addr, trampoline, trampoline_size);
+}
+
+void ccplex_cpu_start(void *entry_addr)
+{
+	struct tegra_pmc_regs * const pmc = PMC_REGS;
+	void * const evp_cpu_reset_vector = EVP_CPU_RESET_VECTOR;
+	void *trampoline;
+	uint32_t entry_point;
+
+	/*
+	 * Just place the trampoline at the MTS_LOAD_ADDRESS. This assumes
+	 * the program to run doesn't overlap this address.
+	 */
+	const uint32_t trampoline_addr = MTS_LOAD_ADDRESS;
+	trampoline = (void *)(uintptr_t)trampoline_addr;
+
+	/* The arm entry points have bit 0 set if thumb code. Mask that off. */
+	entry_point = (uint32_t)(uintptr_t)entry_addr;
+
+	load_aarch64_trampoline(trampoline);
+
+	/* Warm reset vector is pulled from the PMC scratch registers. */
+	write32(entry_point, &pmc->secure_scratch34);
+	write32(0, &pmc->secure_scratch35);
+
+	printk(BIOS_DEBUG, "Starting CPU0 @ %p trampolining to %08x.\n",
+		trampoline, entry_point);
+
+	/*
+	 * The Denver cores start in 32-bit mode. Therefore a trampoline
+	 * is needed to get into 64-bit mode. Point the cold reset vector
+	 * to the trampoline location.
+	 */
+	write32(trampoline_addr, evp_cpu_reset_vector);
+
+	start_cpu0();
+}
diff --git a/src/soc/nvidia/tegra132/ccplex.h b/src/soc/nvidia/tegra132/ccplex.h
index 6b9699cded..c3f8a04534 100644
--- a/src/soc/nvidia/tegra132/ccplex.h
+++ b/src/soc/nvidia/tegra132/ccplex.h
@@ -22,7 +22,13 @@
 
 #define MTS_LOAD_ADDRESS 0x82000000
 
+/* Prepare the clocks and rails to start the cpu. */
+void ccplex_cpu_prepare(void);
+
 /* Loads the MTS microcode. Return 0 on success, < 0 on error. */
 int ccplex_load_mts(void);
 
+/* Start cpu0 and have it start executing at entry_addr */
+void ccplex_cpu_start(void *entry_addr);
+
 #endif /* __SOC_NVIDIA_TEGRA132_CCPLEX_H__ */
diff --git a/src/soc/nvidia/tegra132/include/soc/romstage.h b/src/soc/nvidia/tegra132/include/soc/romstage.h
new file mode 100644
index 0000000000..f9eac26e0d
--- /dev/null
+++ b/src/soc/nvidia/tegra132/include/soc/romstage.h
@@ -0,0 +1,26 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2014 Google Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef __SOC_NVIDIA_TEGRA132_SOC_ROMSTAGE_H__
+#define __SOC_NVIDIA_TEGRA132_SOC_ROMSTAGE_H__
+
+void mainboard_configure_pmc(void);
+void mainboard_enable_vdd_cpu(void);
+
+#endif /* __SOC_NVIDIA_TEGRA132_SOC_ROMSTAGE_H__ */
diff --git a/src/soc/nvidia/tegra132/power.c b/src/soc/nvidia/tegra132/power.c
new file mode 100644
index 0000000000..5c7cc05ef4
--- /dev/null
+++ b/src/soc/nvidia/tegra132/power.c
@@ -0,0 +1,57 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2013 Google Inc.
+ * Copyright (c) 2013, NVIDIA CORPORATION.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <arch/io.h>
+#include <console/console.h>
+#include <soc/addressmap.h>
+
+#include "pmc.h"
+#include "power.h"
+
+static struct tegra_pmc_regs * const pmc = (void *)TEGRA_PMC_BASE;
+
+static int partition_powered(int id)
+{
+	return read32(&pmc->pwrgate_status) & (0x1 << id);
+}
+
+void power_ungate_partition(uint32_t id)
+{
+	printk(BIOS_INFO, "Ungating power partition %d.\n", id);
+
+	if (!partition_powered(id)) {
+		uint32_t pwrgate_toggle = read32(&pmc->pwrgate_toggle);
+		pwrgate_toggle &= ~(PMC_PWRGATE_TOGGLE_PARTID_MASK);
+		pwrgate_toggle |= (id << PMC_PWRGATE_TOGGLE_PARTID_SHIFT);
+		pwrgate_toggle |= PMC_PWRGATE_TOGGLE_START;
+		write32(pwrgate_toggle, &pmc->pwrgate_toggle);
+
+		/* Wait for the request to be accepted. */
+		while (read32(&pmc->pwrgate_toggle) & PMC_PWRGATE_TOGGLE_START)
+			;
+		printk(BIOS_DEBUG, "Power gate toggle request accepted.\n");
+
+		/* Wait for the partition to be powered. */
+		while (!partition_powered(id))
+			;
+	}
+
+	printk(BIOS_INFO, "Ungated power partition %d.\n", id);
+}
diff --git a/src/soc/nvidia/tegra132/power.h b/src/soc/nvidia/tegra132/power.h
index 9283b5583a..b36f91f15f 100644
--- a/src/soc/nvidia/tegra132/power.h
+++ b/src/soc/nvidia/tegra132/power.h
@@ -20,10 +20,8 @@
 #ifndef __SOC_NVIDIA_TEGRA132_POWER_H__
 #define __SOC_NVIDIA_TEGRA132_POWER_H__
 
-// This function does not enable the external power to the rail, it enables
-// the rail itself internal to the SOC.
-void power_enable_cpu_rail(void);
+#include "pmc.h"
 
-void power_ungate_cpu(void);
+void power_ungate_partition(uint32_t id);
 
 #endif	/* __SOC_NVIDIA_TEGRA132_POWER_H__ */
diff --git a/src/soc/nvidia/tegra132/romstage.c b/src/soc/nvidia/tegra132/romstage.c
index 6d51403d04..1d6acca5d0 100644
--- a/src/soc/nvidia/tegra132/romstage.c
+++ b/src/soc/nvidia/tegra132/romstage.c
@@ -39,12 +39,16 @@ void romstage(void)
 	sdram_init(get_sdram_config());
 	printk(BIOS_INFO, "T132 romstage: sdram_init done\n");
 
+	ccplex_cpu_prepare();
+	printk(BIOS_INFO, "T132 romstage: cpu prepare done\n");
+
 	ccplex_load_mts();
 	printk(BIOS_INFO, "T132 romstage: MTS loading done\n");
 
-	while (1);
-
 	entry = cbfs_load_stage(CBFS_DEFAULT_MEDIA,
 				CONFIG_CBFS_PREFIX "/ramstage");
-	stage_exit(entry);
+
+	ccplex_cpu_start(entry);
+
+	while (1);
 }