1 files changed, 258 insertions, 0 deletions
diff --git a/arch/arm/cpu/arm720t/tegra20/cpu.c b/arch/arm/cpu/arm720t/tegra20/cpu.c
new file mode 100644
index 0000000000..6d4d66bced
--- /dev/null
+++ b/arch/arm/cpu/arm720t/tegra20/cpu.c
@@ -0,0 +1,258 @@
+/*
+* (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/tegra20.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 *)TEGRA20_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 *)TEGRA20_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 *)TEGRA20_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 *)TEGRA20_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);
+	}
+}