arm: Tegra2: add support for A9 CPU init

Signed-off-by Tom Warren<[email protected]>

---
Changes for V2:
- Remove returns in void functions
- Move inline assembly code to .S file
- Simplify some if/else code, break out common code
- Minimize the use of local vars
- Inline some single-instance functions
- Remove TRUE/FALSE define, use 1/0 instead
- Replace memset of mem-mapped regs w/loop of writel's
Changes for V3:
- Fix C-style comments in lowlevel_init.S cache_configure

  arch/arm/cpu/armv7/start.S                 |   12 +
  arch/arm/cpu/armv7/tegra2/Makefile         |    2 +-
  arch/arm/cpu/armv7/tegra2/ap20.c           |  366 ++++++++++++++++++++++++++++
  arch/arm/cpu/armv7/tegra2/ap20.h           |  105 ++++++++
  arch/arm/cpu/armv7/tegra2/lowlevel_init.S  |   70 ++++++
  arch/arm/include/asm/arch-tegra2/clk_rst.h |   27 ++
  arch/arm/include/asm/arch-tegra2/pmc.h     |    8 +
  arch/arm/include/asm/arch-tegra2/scu.h     |   43 ++++
  arch/arm/include/asm/arch-tegra2/tegra2.h  |    5 +
  board/nvidia/common/board.c                |   10 +
  board/nvidia/common/board.h                |   29 +++
  include/configs/harmony.h                  |    1 +
  include/configs/seaboard.h                 |    3 +-
  include/configs/tegra2-common.h            |    2 +
  14 files changed, 681 insertions(+), 2 deletions(-)

create mode 100644 arch/arm/cpu/armv7/tegra2/ap20.c create mode 100644 arch/arm/cpu/armv7/tegra2/ap20.h create mode 100644 arch/arm/include/asm/arch-tegra2/scu.h create mode 100644 board/nvidia/common/board.h

arch/arm/cpu/armv7/start.S +12 -0

index cb4f92f..4b36693 100644
@@ -70,6 +70,18 @@ _end_vect:
  _TEXT_BASE:
  	.word	CONFIG_SYS_TEXT_BASE
 
+#ifdef CONFIG_TEGRA2
+/*
+ * Tegra2 uses 2 separate CPUs - the AVP (ARM7TDMI) and the CPU (dual A9s).
+ * U-Boot runs on the AVP first, setting things up for the CPU (PLLs,
+ * muxes, clocks, clamps, etc.). Then the AVP halts, and expects the CPU
+ * to pick up its reset vector, which points here.
+ */
+.globl _armboot_start
+_armboot_start:
+        .word _start
+#endif
+
  /*
   * These are defined in the board-specific linker script.
   */

arch/arm/cpu/armv7/tegra2/Makefile +1 -1

index 687c887..f1ea915 100644
@@ -28,7 +28,7 @@ include $(TOPDIR)/config.mk
  LIB	=  $(obj)lib$(SOC).o
 
  SOBJS	:= lowlevel_init.o
-COBJS	:= board.o sys_info.o timer.o
+COBJS	:= ap20.o board.o sys_info.o timer.o
 
  SRCS	:= $(SOBJS:.o=.S) $(COBJS:.o=.c)
  OBJS	:= $(addprefix $(obj),$(COBJS) $(SOBJS))

arch/arm/cpu/armv7/tegra2/ap20.c new file +105 -0

new file mode 100644
index 0000000..d0ad41f
@@ -0,0 +1,366 @@
+/*
+* (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 "ap20.h"
+#include<asm/io.h>
+#include<asm/arch/tegra2.h>
+#include<asm/arch/clk_rst.h>
+#include<asm/arch/pmc.h>
+#include<asm/arch/pinmux.h>
+#include<asm/arch/scu.h>
+#include<common.h>
+
+u32 s_first_boot = 1;
+
+static void enable_cpu_clock(int enable)
+{
+	struct clk_rst_ctlr *clkrst = (struct clk_rst_ctlr *)NV_PA_CLK_RST_BASE;
+	u32 reg, 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) {
+		/* 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);
+	}
+
+	/* Fetch the register containing the main CPU complex clock enable */
+	reg = readl(&clkrst->crc_clk_out_enb_l);
+	reg |= CLK_ENB_CPU;
+
+	/*
+	 * 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 |= CPU1_CLK_STP;
+
+	if (enable) {
+		/* Unstop the CPU clock */
+		clk&= ~CPU0_CLK_STP;
+	} else {
+		/* Stop the CPU clock */
+		clk |= CPU0_CLK_STP;
+	}
+
+	writel(clk,&clkrst->crc_clk_cpu_cmplx);
+	writel(reg,&clkrst->crc_clk_out_enb_l);
+}
+
+static int is_cpu_powered(void)
+{
+	struct pmc_ctlr *pmc = (struct pmc_ctlr *)NV_PA_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 *)NV_PA_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 *)NV_PA_PMC_BASE;
+	u32 reg;
+

arch/arm/cpu/armv7/tegra2/ap20.c new file +118 -0

+		/*
+		 * 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 *)NV_PA_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)
+{
+	struct clk_rst_ctlr *clkrst = (struct clk_rst_ctlr *)NV_PA_CLK_RST_BASE;
+	u32 reg, cpu;
+
+	/*
+	* 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 */
+	cpu = SET_DBGRESET1 | SET_DERESET1 | SET_CPURESET1;
+	writel(cpu,&clkrst->crc_cpu_cmplx_set);
+
+	reg = readl(&clkrst->crc_rst_dev_l);
+	if (reset) {
+		/* Now place CPU0 into reset */
+		cpu |= SET_DBGRESET0 | SET_DERESET0 | SET_CPURESET0;
+		writel(cpu,&clkrst->crc_cpu_cmplx_set);
+
+		/* Enable master CPU reset */
+		reg |= SWR_CPU_RST;
+	} else {
+		/* Take CPU0 out of reset */
+		cpu = CLR_DBGRESET0 | CLR_DERESET0 | CLR_CPURESET0;
+		writel(cpu,&clkrst->crc_cpu_cmplx_clr);
+
+		/* Disable master CPU reset */
+		reg&= ~SWR_CPU_RST;
+	}
+
+	writel(reg,&clkrst->crc_rst_dev_l);
+}
+
+static void clock_enable_coresight(int enable)
+{
+	struct clk_rst_ctlr *clkrst = (struct clk_rst_ctlr *)NV_PA_CLK_RST_BASE;
+	u32 rst, clk, src;
+
+	rst = readl(&clkrst->crc_rst_dev_u);
+	clk = readl(&clkrst->crc_clk_out_enb_u);
+
+	if (enable) {
+		rst&= ~SWR_CSITE_RST;
+		clk |= CLK_ENB_CSITE;
+	} else {
+		rst |= SWR_CSITE_RST;
+		clk&= ~CLK_ENB_CSITE;
+	}
+
+	writel(clk,&clkrst->crc_clk_out_enb_u);
+	writel(rst,&clkrst->crc_rst_dev_u);
+
+	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);
+		writel(src,&clkrst->crc_clk_src_csite);
+
+		/* 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.

arch/arm/cpu/armv7/tegra2/ap20.c new file +66 -0

+void enable_scu(void)
+{
+	struct scu_ctlr *scu = (struct scu_ctlr *)NV_PA_ARM_PERIPHBASE;
+	u32 reg;
+
+	/* If SCU already setup/enabled, return */
+	if (readl(&scu->scu_ctrl)&  SCU_CTRL_ENABLE)
+		return;
+
+	/* Invalidate all ways for all processors */
+	writel(0xFFFF,&scu->scu_inv_all);
+
+	/* Enable SCU - bit 0 */
+	reg = readl(&scu->scu_ctrl);
+	reg |= SCU_CTRL_ENABLE;
+	writel(reg,&scu->scu_ctrl);
+}
+
+void init_pmc_scratch(void)
+{
+	struct pmc_ctlr *const pmc = (struct pmc_ctlr *)NV_PA_PMC_BASE;
+	int i;
+
+	/* SCRATCH0 is initialized by the boot ROM and shouldn't be cleared */
+	for (i = 0; i<  23; i++)
+		writel(0,&pmc->pmc_scratch1+i);
+
+	/* ODMDATA is for kernel use to determine RAM size, LP config, etc. */
+	writel(CONFIG_SYS_BOARD_ODMDATA,&pmc->pmc_scratch20);
+}
+
+void cpu_start(void)
+{
+	struct pmux_tri_ctlr *pmt = (struct pmux_tri_ctlr *)NV_PA_APB_MISC_BASE;
+
+	/* enable JTAG */
+	writel(0xC0,&pmt->pmt_cfg_ctl);
+
+	if (s_first_boot) {
+		/*
+		 * Need to set this before cold-booting,
+		 *  otherwise we'll end up in an infinite loop.
+		 */
+		s_first_boot = 0;
+		cold_boot();
+	}
+}
+
+void tegra2_start()
+{
+	if (s_first_boot) {
+		/* Init Debug UART Port (115200 8n1) */
+		uart_init();
+
+		/* Init PMC scratch memory */
+		init_pmc_scratch();
+	}
+
+#ifdef CONFIG_ENABLE_CORTEXA9
+	/* take the mpcore out of reset */
+	cpu_start();
+
+	/* configure cache */
+	cache_configure();
+#endif
+}