Patchwork [U-Boot,5/9] ARM: add tegra support to arm720t

login
register
mail settings
Submitter Allen Martin
Date May 10, 2012, 7:02 a.m.
Message ID <1336633347-8049-6-git-send-email-amartin@nvidia.com>
Download mbox | patch
Permalink /patch/158207/
State Superseded
Headers show

Comments

Allen Martin - May 10, 2012, 7:02 a.m.
Add support for tegra arm7 boot processor.  This processor is used to
power on the Cortex A9 and transfer control to it.

Signed-off-by: Allen Martin <amartin@nvidia.com>
---
 arch/arm/cpu/arm720t/cpu.c                  |    3 +-
 arch/arm/cpu/arm720t/interrupts.c           |    5 +-
 arch/arm/cpu/arm720t/start.S                |    6 +-
 arch/arm/cpu/arm720t/tegra2/Makefile        |   48 +++++
 arch/arm/cpu/arm720t/tegra2/board.h         |   25 +++
 arch/arm/cpu/arm720t/tegra2/cpu.c           |  259 +++++++++++++++++++++++++++
 arch/arm/cpu/arm720t/tegra2/cpu.h           |   99 ++++++++++
 arch/arm/cpu/arm720t/tegra2/spl.c           |  133 ++++++++++++++
 arch/arm/include/asm/arch-tegra2/hardware.h |   29 +++
 9 files changed, 604 insertions(+), 3 deletions(-)
 create mode 100644 arch/arm/cpu/arm720t/tegra2/Makefile
 create mode 100644 arch/arm/cpu/arm720t/tegra2/board.h
 create mode 100644 arch/arm/cpu/arm720t/tegra2/cpu.c
 create mode 100644 arch/arm/cpu/arm720t/tegra2/cpu.h
 create mode 100644 arch/arm/cpu/arm720t/tegra2/spl.c
 create mode 100644 arch/arm/include/asm/arch-tegra2/hardware.h
Stephen Warren - May 15, 2012, 5:03 a.m.
On 05/10/2012 01:02 AM, Allen Martin wrote:
> Add support for tegra arm7 boot processor.  This processor is used to
> power on the Cortex A9 and transfer control to it.

> +static void enable_cpu_power_rail(void)

> +	/*
> +	 * The TI PMU65861C needs a 3.75ms delay between enabling
> +	 * the power rail and enabling the CPU clock.  This delay
> +	 * between SM1EN and SM1 is for switching time + the ramp
> +	 * up of the voltage to the CPU (VDD_CPU from PMU).
> +	 */
> +	udelay(3750);

Not all boards use that PMU. Can this be conditional on a define that
enables that PMU, or part of the PMU diver or something?

> diff --git a/arch/arm/cpu/arm720t/tegra2/cpu.h b/arch/arm/cpu/arm720t/tegra2/cpu.h

> + * 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; either version 2 of
> + * the License, or (at your option) any later version.

Is this new code you just wrote? If so, shouldn't it be GPL v2 not GPL v2+?
Allen Martin - May 18, 2012, 10:37 p.m.
On Mon, May 14, 2012 at 10:03:24PM -0700, Stephen Warren wrote:
> On 05/10/2012 01:02 AM, Allen Martin wrote:
> > Add support for tegra arm7 boot processor.  This processor is used to
> > power on the Cortex A9 and transfer control to it.
> 
> > +static void enable_cpu_power_rail(void)
> 
> > +	/*
> > +	 * The TI PMU65861C needs a 3.75ms delay between enabling
> > +	 * the power rail and enabling the CPU clock.  This delay
> > +	 * between SM1EN and SM1 is for switching time + the ramp
> > +	 * up of the voltage to the CPU (VDD_CPU from PMU).
> > +	 */
> > +	udelay(3750);
> 
> Not all boards use that PMU. Can this be conditional on a define that
> enables that PMU, or part of the PMU diver or something?

Sounds reasonable, although I think it should be part of a separate
patch.  This code I just moved unmodified from ap20.c in the armv7
tegra2 directory.

> 
> > diff --git a/arch/arm/cpu/arm720t/tegra2/cpu.h b/arch/arm/cpu/arm720t/tegra2/cpu.h
> 
> > + * 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; either version 2 of
> > + * the License, or (at your option) any later version.
> 
> Is this new code you just wrote? If so, shouldn't it be GPL v2 not GPL v2+?

Again I just moved it unmodified (copyright and all) from ap20.h.  

-Allen
Stephen Warren - May 22, 2012, 5:10 p.m.
On 05/18/2012 04:37 PM, Allen Martin wrote:
> On Mon, May 14, 2012 at 10:03:24PM -0700, Stephen Warren wrote:
>> On 05/10/2012 01:02 AM, Allen Martin wrote:
>>> Add support for tegra arm7 boot processor.  This processor is used to
>>> power on the Cortex A9 and transfer control to it.
>>
>>> +static void enable_cpu_power_rail(void)
>>
>>> +	/*
>>> +	 * The TI PMU65861C needs a 3.75ms delay between enabling
>>> +	 * the power rail and enabling the CPU clock.  This delay
>>> +	 * between SM1EN and SM1 is for switching time + the ramp
>>> +	 * up of the voltage to the CPU (VDD_CPU from PMU).
>>> +	 */
>>> +	udelay(3750);
>>
>> Not all boards use that PMU. Can this be conditional on a define that
>> enables that PMU, or part of the PMU diver or something?
> 
> Sounds reasonable, although I think it should be part of a separate
> patch.  This code I just moved unmodified from ap20.c in the armv7
> tegra2 directory.
>
>>> diff --git a/arch/arm/cpu/arm720t/tegra2/cpu.h b/arch/arm/cpu/arm720t/tegra2/cpu.h
>>
>>> + * 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; either version 2 of
>>> + * the License, or (at your option) any later version.
>>
>> Is this new code you just wrote? If so, shouldn't it be GPL v2 not GPL v2+?
> 
> Again I just moved it unmodified (copyright and all) from ap20.h.  

Oh right. I think if you pass "-M" or better "-C" to "git format-patch",
it'll highlight that fact better; it should make the patch file indicate
that the relevant files were moved or copied, and just show the diffs to
the file during the move/copy (which may be zero or tiny), rather than
showing the entire file as new code.
Allen Martin - May 22, 2012, 7:14 p.m.
On Tue, May 22, 2012 at 10:10:48AM -0700, Stephen Warren wrote:
> Oh right. I think if you pass "-M" or better "-C" to "git format-patch",
> it'll highlight that fact better; it should make the patch file indicate
> that the relevant files were moved or copied, and just show the diffs to
> the file during the move/copy (which may be zero or tiny), rather than
> showing the entire file as new code.

Sorry about that, I did it correctly in my earlier posting of this
patch, but incorrectly when I posted the entire patch series.  I'll
use -C when I post V2.

-Allen

Patch

diff --git a/arch/arm/cpu/arm720t/cpu.c b/arch/arm/cpu/arm720t/cpu.c
index 974f288..cfbfa3d 100644
--- a/arch/arm/cpu/arm720t/cpu.c
+++ b/arch/arm/cpu/arm720t/cpu.c
@@ -33,7 +33,6 @@ 
 #include <common.h>
 #include <command.h>
 #include <clps7111.h>
-#include <asm/hardware.h>
 #include <asm/system.h>
 
 int cleanup_before_linux (void)
@@ -51,6 +50,8 @@  int cleanup_before_linux (void)
 	/* Nothing more needed */
 #elif defined(CONFIG_INTEGRATOR) && defined(CONFIG_ARCH_INTEGRATOR)
 	/* No cleanup before linux for IntegratorAP/CM720T as yet */
+#elif defined (CONFIG_MACH_TEGRA_GENERIC)
+	/* No cleanup before linux for tegra as yet */
 #else
 #error No cleanup_before_linux() defined for this CPU type
 #endif
diff --git a/arch/arm/cpu/arm720t/interrupts.c b/arch/arm/cpu/arm720t/interrupts.c
index 464dd30..aa909ef 100644
--- a/arch/arm/cpu/arm720t/interrupts.c
+++ b/arch/arm/cpu/arm720t/interrupts.c
@@ -29,7 +29,6 @@ 
 #include <common.h>
 #include <clps7111.h>
 #include <asm/proc-armv/ptrace.h>
-#include <asm/hardware.h>
 
 #ifndef CONFIG_NETARM
 /* we always count down the max. */
@@ -180,6 +179,8 @@  int timer_init (void)
 	PUT32(T0TC, 0);
 	PUT32(T0TCR, 1);	/* enable timer0 */
 
+#elif defined(CONFIG_MACH_TEGRA_GENERIC)
+	/* No timer routines for tegra as yet */
 #else
 #error No timer_init() defined for this CPU type
 #endif
@@ -282,6 +283,8 @@  void __udelay (unsigned long usec)
 
 #elif defined(CONFIG_INTEGRATOR) && defined(CONFIG_ARCH_INTEGRATOR)
 	/* No timer routines for IntegratorAP/CM720T as yet */
+#elif defined(CONFIG_MACH_TEGRA_GENERIC)
+	/* No timer routines for tegra as yet */
 #else
 #error Timer routines not defined for this CPU type
 #endif
diff --git a/arch/arm/cpu/arm720t/start.S b/arch/arm/cpu/arm720t/start.S
index df66946..e79b1be 100644
--- a/arch/arm/cpu/arm720t/start.S
+++ b/arch/arm/cpu/arm720t/start.S
@@ -407,6 +407,8 @@  lock_loop:
 	ldr	r0, VPBDIV_ADR
 	mov	r1, #0x01	/* VPB clock is same as process clock */
 	str	r1, [r0]
+#elif defined(CONFIG_MACH_TEGRA_GENERIC)
+	/* No cpu_init_crit for tegra as yet */
 #else
 #error No cpu_init_crit() defined for current CPU type
 #endif
@@ -422,7 +424,7 @@  lock_loop:
 	str	r1, [r0]
 #endif
 
-#ifndef CONFIG_LPC2292
+#if !defined(CONFIG_LPC2292) && !defined(CONFIG_MACH_TEGRA_GENERIC)
 	mov	ip, lr
 	/*
 	 * before relocating, we have to setup RAM timing
@@ -631,6 +633,8 @@  reset_cpu:
 .globl reset_cpu
 reset_cpu:
 	mov	pc, r0
+#elif defined(CONFIG_MACH_TEGRA_GENERIC)
+	/* No specific reset actions for tegra as yet */
 #else
 #error No reset_cpu() defined for current CPU type
 #endif
diff --git a/arch/arm/cpu/arm720t/tegra2/Makefile b/arch/arm/cpu/arm720t/tegra2/Makefile
new file mode 100644
index 0000000..6e48475
--- /dev/null
+++ b/arch/arm/cpu/arm720t/tegra2/Makefile
@@ -0,0 +1,48 @@ 
+#
+# (C) Copyright 2010,2011 Nvidia Corporation.
+#
+# (C) Copyright 2000-2008
+# Wolfgang Denk, DENX Software Engineering, wd@denx.de.
+#
+# See file CREDITS for list of people who contributed to this
+# project.
+#
+# 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; either version 2 of
+# the License, or (at your option) any later version.
+#
+# 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., 59 Temple Place, Suite 330, Boston,
+# MA 02111-1307 USA
+#
+
+include $(TOPDIR)/config.mk
+
+LIB	= $(obj)lib$(SOC).o
+
+COBJS-y	+= cpu.o
+COBJS-$(CONFIG_SPL_BUILD) += spl.o
+
+SRCS	:= $(COBJS-y:.o=.c)
+OBJS	:= $(addprefix $(obj),$(COBJS-y))
+
+all:	$(obj).depend $(LIB)
+
+$(LIB):	$(OBJS)
+	$(call cmd_link_o_target, $(OBJS))
+
+#########################################################################
+
+# defines $(obj).depend target
+include $(SRCTREE)/rules.mk
+
+sinclude $(obj).depend
+
+#########################################################################
diff --git a/arch/arm/cpu/arm720t/tegra2/board.h b/arch/arm/cpu/arm720t/tegra2/board.h
new file mode 100644
index 0000000..61b91c0
--- /dev/null
+++ b/arch/arm/cpu/arm720t/tegra2/board.h
@@ -0,0 +1,25 @@ 
+/*
+ * (C) Copyright 2010-2011
+ * NVIDIA Corporation <www.nvidia.com>
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * 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., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+void board_init_uart_f(void);
+void gpio_config_uart(void);
diff --git a/arch/arm/cpu/arm720t/tegra2/cpu.c b/arch/arm/cpu/arm720t/tegra2/cpu.c
new file mode 100644
index 0000000..00a82b1
--- /dev/null
+++ b/arch/arm/cpu/arm720t/tegra2/cpu.c
@@ -0,0 +1,259 @@ 
+/*
+* (C) Copyright 2010-2011
+* NVIDIA Corporation <www.nvidia.com>
+*
+* See file CREDITS for list of people who contributed to this
+* project.
+*
+* 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; either version 2 of
+* the License, or (at your option) any later version.
+*
+* 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., 59 Temple Place, Suite 330, Boston,
+* MA 02111-1307 USA
+*/
+
+#include <asm/io.h>
+#include <asm/arch/tegra2.h>
+#include <asm/arch/clk_rst.h>
+#include <asm/arch/clock.h>
+#include <asm/arch/pmc.h>
+#include <asm/arch/pinmux.h>
+#include <asm/arch/scu.h>
+#include <common.h>
+#include "cpu.h"
+
+/* Returns 1 if the current CPU executing is a Cortex-A9, else 0 */
+int ap20_cpu_is_cortexa9(void)
+{
+	u32 id = readb(NV_PA_PG_UP_BASE + PG_UP_TAG_0);
+	return id == (PG_UP_TAG_0_PID_CPU & 0xff);
+}
+
+void init_pllx(void)
+{
+	struct clk_rst_ctlr *clkrst = (struct clk_rst_ctlr *)NV_PA_CLK_RST_BASE;
+	struct clk_pll *pll = &clkrst->crc_pll[CLOCK_ID_XCPU];
+	u32 reg;
+
+	/* If PLLX is already enabled, just return */
+	if (readl(&pll->pll_base) & PLL_ENABLE_MASK)
+		return;
+
+	/* Set PLLX_MISC */
+	writel(1 << PLL_CPCON_SHIFT, &pll->pll_misc);
+
+	/* Use 12MHz clock here */
+	reg = PLL_BYPASS_MASK | (12 << PLL_DIVM_SHIFT);
+	reg |= 1000 << PLL_DIVN_SHIFT;
+	writel(reg, &pll->pll_base);
+
+	reg |= PLL_ENABLE_MASK;
+	writel(reg, &pll->pll_base);
+
+	reg &= ~PLL_BYPASS_MASK;
+	writel(reg, &pll->pll_base);
+}
+
+static void enable_cpu_clock(int enable)
+{
+	struct clk_rst_ctlr *clkrst = (struct clk_rst_ctlr *)NV_PA_CLK_RST_BASE;
+	u32 clk;
+
+	/*
+	 * NOTE:
+	 * Regardless of whether the request is to enable or disable the CPU
+	 * clock, every processor in the CPU complex except the master (CPU 0)
+	 * will have it's clock stopped because the AVP only talks to the
+	 * master. The AVP does not know (nor does it need to know) that there
+	 * are multiple processors in the CPU complex.
+	 */
+
+	if (enable) {
+		/* Initialize PLLX */
+		init_pllx();
+
+		/* Wait until all clocks are stable */
+		udelay(PLL_STABILIZATION_DELAY);
+
+		writel(CCLK_BURST_POLICY, &clkrst->crc_cclk_brst_pol);
+		writel(SUPER_CCLK_DIVIDER, &clkrst->crc_super_cclk_div);
+	}
+
+	/*
+	 * Read the register containing the individual CPU clock enables and
+	 * always stop the clock to CPU 1.
+	 */
+	clk = readl(&clkrst->crc_clk_cpu_cmplx);
+	clk |= 1 << CPU1_CLK_STP_SHIFT;
+
+	/* Stop/Unstop the CPU clock */
+	clk &= ~CPU0_CLK_STP_MASK;
+	clk |= !enable << CPU0_CLK_STP_SHIFT;
+	writel(clk, &clkrst->crc_clk_cpu_cmplx);
+
+	clock_enable(PERIPH_ID_CPU);
+}
+
+static int is_cpu_powered(void)
+{
+	struct pmc_ctlr *pmc = (struct pmc_ctlr *)TEGRA2_PMC_BASE;
+
+	return (readl(&pmc->pmc_pwrgate_status) & CPU_PWRED) ? 1 : 0;
+}
+
+static void remove_cpu_io_clamps(void)
+{
+	struct pmc_ctlr *pmc = (struct pmc_ctlr *)TEGRA2_PMC_BASE;
+	u32 reg;
+
+	/* Remove the clamps on the CPU I/O signals */
+	reg = readl(&pmc->pmc_remove_clamping);
+	reg |= CPU_CLMP;
+	writel(reg, &pmc->pmc_remove_clamping);
+
+	/* Give I/O signals time to stabilize */
+	udelay(IO_STABILIZATION_DELAY);
+}
+
+static void powerup_cpu(void)
+{
+	struct pmc_ctlr *pmc = (struct pmc_ctlr *)TEGRA2_PMC_BASE;
+	u32 reg;
+	int timeout = IO_STABILIZATION_DELAY;
+
+	if (!is_cpu_powered()) {
+		/* Toggle the CPU power state (OFF -> ON) */
+		reg = readl(&pmc->pmc_pwrgate_toggle);
+		reg &= PARTID_CP;
+		reg |= START_CP;
+		writel(reg, &pmc->pmc_pwrgate_toggle);
+
+		/* Wait for the power to come up */
+		while (!is_cpu_powered()) {
+			if (timeout-- == 0)
+				printf("CPU failed to power up!\n");
+			else
+				udelay(10);
+		}
+
+		/*
+		 * Remove the I/O clamps from CPU power partition.
+		 * Recommended only on a Warm boot, if the CPU partition gets
+		 * power gated. Shouldn't cause any harm when called after a
+		 * cold boot according to HW, probably just redundant.
+		 */
+		remove_cpu_io_clamps();
+	}
+}
+
+static void enable_cpu_power_rail(void)
+{
+	struct pmc_ctlr *pmc = (struct pmc_ctlr *)TEGRA2_PMC_BASE;
+	u32 reg;
+
+	reg = readl(&pmc->pmc_cntrl);
+	reg |= CPUPWRREQ_OE;
+	writel(reg, &pmc->pmc_cntrl);
+
+	/*
+	 * The TI PMU65861C needs a 3.75ms delay between enabling
+	 * the power rail and enabling the CPU clock.  This delay
+	 * between SM1EN and SM1 is for switching time + the ramp
+	 * up of the voltage to the CPU (VDD_CPU from PMU).
+	 */
+	udelay(3750);
+}
+
+static void reset_A9_cpu(int reset)
+{
+	/*
+	* NOTE:  Regardless of whether the request is to hold the CPU in reset
+	*        or take it out of reset, every processor in the CPU complex
+	*        except the master (CPU 0) will be held in reset because the
+	*        AVP only talks to the master. The AVP does not know that there
+	*        are multiple processors in the CPU complex.
+	*/
+
+	/* Hold CPU 1 in reset, and CPU 0 if asked */
+	reset_cmplx_set_enable(1, crc_rst_cpu | crc_rst_de | crc_rst_debug, 1);
+	reset_cmplx_set_enable(0, crc_rst_cpu | crc_rst_de | crc_rst_debug,
+			       reset);
+
+	/* Enable/Disable master CPU reset */
+	reset_set_enable(PERIPH_ID_CPU, reset);
+}
+
+static void clock_enable_coresight(int enable)
+{
+	u32 rst, src;
+
+	clock_set_enable(PERIPH_ID_CORESIGHT, enable);
+	reset_set_enable(PERIPH_ID_CORESIGHT, !enable);
+
+	if (enable) {
+		/*
+		 * Put CoreSight on PLLP_OUT0 (216 MHz) and divide it down by
+		 *  1.5, giving an effective frequency of 144MHz.
+		 * Set PLLP_OUT0 [bits31:30 = 00], and use a 7.1 divisor
+		 *  (bits 7:0), so 00000001b == 1.5 (n+1 + .5)
+		 */
+		src = CLK_DIVIDER(NVBL_PLLP_KHZ, 144000);
+		clock_ll_set_source_divisor(PERIPH_ID_CSI, 0, src);
+
+		/* Unlock the CPU CoreSight interfaces */
+		rst = 0xC5ACCE55;
+		writel(rst, CSITE_CPU_DBG0_LAR);
+		writel(rst, CSITE_CPU_DBG1_LAR);
+	}
+}
+
+void start_cpu(u32 reset_vector)
+{
+	/* Enable VDD_CPU */
+	enable_cpu_power_rail();
+
+	/* Hold the CPUs in reset */
+	reset_A9_cpu(1);
+
+	/* Disable the CPU clock */
+	enable_cpu_clock(0);
+
+	/* Enable CoreSight */
+	clock_enable_coresight(1);
+
+	/*
+	 * Set the entry point for CPU execution from reset,
+	 *  if it's a non-zero value.
+	 */
+	if (reset_vector)
+		writel(reset_vector, EXCEP_VECTOR_CPU_RESET_VECTOR);
+
+	/* Enable the CPU clock */
+	enable_cpu_clock(1);
+
+	/* If the CPU doesn't already have power, power it up */
+	powerup_cpu();
+
+	/* Take the CPU out of reset */
+	reset_A9_cpu(0);
+}
+
+
+void halt_avp(void)
+{
+	for (;;) {
+		writel((HALT_COP_EVENT_JTAG | HALT_COP_EVENT_IRQ_1 \
+			| HALT_COP_EVENT_FIQ_1 | (FLOW_MODE_STOP<<29)),
+			FLOW_CTLR_HALT_COP_EVENTS);
+	}
+}
+
diff --git a/arch/arm/cpu/arm720t/tegra2/cpu.h b/arch/arm/cpu/arm720t/tegra2/cpu.h
new file mode 100644
index 0000000..90857a8
--- /dev/null
+++ b/arch/arm/cpu/arm720t/tegra2/cpu.h
@@ -0,0 +1,99 @@ 
+/*
+ * (C) Copyright 2010-2011
+ * NVIDIA Corporation <www.nvidia.com>
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * 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., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+#include <asm/types.h>
+
+/* Stabilization delays, in usec */
+#define PLL_STABILIZATION_DELAY (300)
+#define IO_STABILIZATION_DELAY	(1000)
+
+#define NVBL_PLLP_KHZ	(216000)
+
+#define PLLX_ENABLED		(1 << 30)
+#define CCLK_BURST_POLICY	0x20008888
+#define SUPER_CCLK_DIVIDER	0x80000000
+
+/* Calculate clock fractional divider value from ref and target frequencies */
+#define CLK_DIVIDER(REF, FREQ)  ((((REF) * 2) / FREQ) - 2)
+
+/* Calculate clock frequency value from reference and clock divider value */
+#define CLK_FREQUENCY(REF, REG)  (((REF) * 2) / (REG + 2))
+
+/* AVP/CPU ID */
+#define PG_UP_TAG_0_PID_CPU	0x55555555	/* CPU aka "a9" aka "mpcore" */
+#define PG_UP_TAG_0             0x0
+
+#define CORESIGHT_UNLOCK	0xC5ACCE55;
+
+/* AP20-Specific Base Addresses */
+
+/* AP20 Base physical address of SDRAM. */
+#define AP20_BASE_PA_SDRAM      0x00000000
+/* AP20 Base physical address of internal SRAM. */
+#define AP20_BASE_PA_SRAM       0x40000000
+/* AP20 Size of internal SRAM (256KB). */
+#define AP20_BASE_PA_SRAM_SIZE  0x00040000
+/* AP20 Base physical address of flash. */
+#define AP20_BASE_PA_NOR_FLASH  0xD0000000
+/* AP20 Base physical address of boot information table. */
+#define AP20_BASE_PA_BOOT_INFO  AP20_BASE_PA_SRAM
+
+/*
+ * Super-temporary stacks for EXTREMELY early startup. The values chosen for
+ * these addresses must be valid on ALL SOCs because this value is used before
+ * we are able to differentiate between the SOC types.
+ *
+ * NOTE: The since CPU's stack will eventually be moved from IRAM to SDRAM, its
+ *       stack is placed below the AVP stack. Once the CPU stack has been moved,
+ *       the AVP is free to use the IRAM the CPU stack previously occupied if
+ *       it should need to do so.
+ *
+ * NOTE: In multi-processor CPU complex configurations, each processor will have
+ *       its own stack of size CPU_EARLY_BOOT_STACK_SIZE. CPU 0 will have a
+ *       limit of CPU_EARLY_BOOT_STACK_LIMIT. Each successive CPU will have a
+ *       stack limit that is CPU_EARLY_BOOT_STACK_SIZE less then the previous
+ *       CPU.
+ */
+
+/* Common AVP early boot stack limit */
+#define AVP_EARLY_BOOT_STACK_LIMIT	\
+	(AP20_BASE_PA_SRAM + (AP20_BASE_PA_SRAM_SIZE/2))
+/* Common AVP early boot stack size */
+#define AVP_EARLY_BOOT_STACK_SIZE	0x1000
+/* Common CPU early boot stack limit */
+#define CPU_EARLY_BOOT_STACK_LIMIT	\
+	(AVP_EARLY_BOOT_STACK_LIMIT - AVP_EARLY_BOOT_STACK_SIZE)
+/* Common CPU early boot stack size */
+#define CPU_EARLY_BOOT_STACK_SIZE	0x1000
+
+#define EXCEP_VECTOR_CPU_RESET_VECTOR	(NV_PA_EVP_BASE + 0x100)
+#define CSITE_CPU_DBG0_LAR		(NV_PA_CSITE_BASE + 0x10FB0)
+#define CSITE_CPU_DBG1_LAR		(NV_PA_CSITE_BASE + 0x12FB0)
+
+#define FLOW_CTLR_HALT_COP_EVENTS	(NV_PA_FLOW_BASE + 4)
+#define FLOW_MODE_STOP			2
+#define HALT_COP_EVENT_JTAG		(1 << 28)
+#define HALT_COP_EVENT_IRQ_1		(1 << 11)
+#define HALT_COP_EVENT_FIQ_1		(1 << 9)
+
+void start_cpu(u32 reset_vector);
+int ap20_cpu_is_cortexa9(void);
diff --git a/arch/arm/cpu/arm720t/tegra2/spl.c b/arch/arm/cpu/arm720t/tegra2/spl.c
new file mode 100644
index 0000000..d467ab2
--- /dev/null
+++ b/arch/arm/cpu/arm720t/tegra2/spl.c
@@ -0,0 +1,133 @@ 
+/*
+ * (C) Copyright 2012
+ * NVIDIA Inc, <www.nvidia.com>
+ *
+ * Allen Martin <amartin@nvidia.com>
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * 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., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+#include <common.h>
+#include <asm/u-boot.h>
+#include <asm/utils.h>
+#include <asm/arch/sys_proto.h>
+#include <asm/arch/clock.h>
+#include <nand.h>
+#include <mmc.h>
+#include <fat.h>
+#include <version.h>
+#include <i2c.h>
+#include <image.h>
+#include <malloc.h>
+#include <linux/compiler.h>
+#include "board.h"
+#include "cpu.h"
+
+#include <asm/io.h>
+#include <asm/arch/tegra2.h>
+#include <asm/arch/clk_rst.h>
+#include <asm/arch/clock.h>
+#include <asm/arch/pmc.h>
+#include <asm/arch/pinmux.h>
+#include <asm/arch/scu.h>
+#include <common.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+/* Define global data structure pointer to it*/
+static gd_t gdata __attribute__ ((section(".data")));
+static bd_t bdata __attribute__ ((section(".data")));
+
+inline void hang(void)
+{
+	puts("### ERROR ### Please RESET the board ###\n");
+	for (;;)
+		;
+}
+
+void board_init_f(ulong dummy)
+{
+	board_init_uart_f();
+
+	/* Initialize periph GPIOs */
+#ifdef CONFIG_SPI_UART_SWITCH
+	gpio_early_init_uart();
+#else
+	gpio_config_uart();
+#endif
+
+	/*
+	 * We call relocate_code() with relocation target same as the
+	 * CONFIG_SYS_SPL_TEXT_BASE. This will result in relocation getting
+	 * skipped. Instead, only .bss initialization will happen. That's
+	 * all we need
+	 */
+	debug(">>board_init_f()\n");
+	relocate_code(CONFIG_SPL_STACK, &gdata, CONFIG_SPL_TEXT_BASE);
+}
+
+/* This requires UART clocks to be enabled */
+static void preloader_console_init(void)
+{
+	const char *u_boot_rev = U_BOOT_VERSION;
+
+	gd = &gdata;
+	gd->bd = &bdata;
+	gd->flags |= GD_FLG_RELOC;
+	gd->baudrate = CONFIG_BAUDRATE;
+
+	serial_init();		/* serial communications setup */
+
+	gd->have_console = 1;
+
+	/* Avoid a second "U-Boot" coming from this string */
+	u_boot_rev = &u_boot_rev[7];
+
+	printf("\nU-Boot SPL %s (%s - %s)\n", u_boot_rev, U_BOOT_DATE,
+		U_BOOT_TIME);
+}
+
+void board_init_r(gd_t *id, ulong dummy)
+{
+	u32 boot_device;
+	struct pmux_tri_ctlr *pmt = (struct pmux_tri_ctlr *)NV_PA_APB_MISC_BASE;
+	debug(">>spl:board_init_r()\n");
+
+	mem_malloc_init(CONFIG_SYS_SPL_MALLOC_START,
+			CONFIG_SYS_SPL_MALLOC_SIZE);
+
+#ifdef CONFIG_SPL_BOARD_INIT
+	spl_board_init();
+#endif
+
+	clock_early_init();
+	serial_init();
+	preloader_console_init();
+
+	/* enable JTAG */
+	writel(0xC0, &pmt->pmt_cfg_ctl);
+
+	start_cpu((u32)CONFIG_SYS_TEXT_BASE);
+	halt_avp();
+	/* not reached */
+}
+
+int board_usb_init(const void *blob)
+{
+	return 0;
+}
diff --git a/arch/arm/include/asm/arch-tegra2/hardware.h b/arch/arm/include/asm/arch-tegra2/hardware.h
new file mode 100644
index 0000000..8c47578
--- /dev/null
+++ b/arch/arm/include/asm/arch-tegra2/hardware.h
@@ -0,0 +1,29 @@ 
+/*
+* (C) Copyright 2010-2011
+* NVIDIA Corporation <www.nvidia.com>
+*
+* See file CREDITS for list of people who contributed to this
+* project.
+*
+* 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; either version 2 of
+* the License, or (at your option) any later version.
+*
+* 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., 59 Temple Place, Suite 330, Boston,
+* MA 02111-1307 USA
+*/
+
+#ifndef __TEGRA2_HW_H
+#define __TEGRA2_HW_H
+
+/* include tegra specific hardware definitions */
+
+#endif /* __TEGRA2_HW_H */