/*
* Copyright (C) 2013 Lucas Stach <l.stach@pengutronix.de>
*
* Partly based on code (C) Copyright 2010-2011
* NVIDIA Corporation <www.nvidia.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope 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, see <http://www.gnu.org/licenses/>.
*/
#include <common.h>
#include <asm/barebox-arm-head.h>
#include <mach/lowlevel.h>
#include <mach/tegra20-car.h>
#include <mach/tegra20-pmc.h>
static inline void tegra_cpu_lowlevel_setup(void)
{
uint32_t r;
/* set the cpu to SVC32 mode */
__asm__ __volatile__("mrs %0, cpsr":"=r"(r));
r &= ~0x1f;
r |= 0xd3;
__asm__ __volatile__("msr cpsr, %0" : : "r"(r));
}
/* instruct the PMIC to enable the CPU power rail */
static void enable_maincomplex_powerrail(void)
{
u32 reg;
reg = readl(TEGRA_PMC_BASE + PMC_CNTRL);
reg |= PMC_CNTRL_CPUPWRREQ_OE;
writel(reg, TEGRA_PMC_BASE);
}
/* put every core in the main CPU complex into reset state */
static void assert_maincomplex_reset(int num_cores)
{
u32 mask = 0;
int i;
for (i = 0; i < num_cores; i++)
mask |= 0x1111 << i;
writel(mask, TEGRA_CLK_RESET_BASE + CRC_RST_CPU_CMPLX_SET);
writel(CRC_RST_DEV_L_CPU, TEGRA_CLK_RESET_BASE + CRC_RST_DEV_L_SET);
}
/* release reset state of the first core of the main CPU complex */
static void deassert_cpu0_reset(void)
{
writel(0x1111, TEGRA_CLK_RESET_BASE + CRC_RST_CPU_CMPLX_CLR);
writel(CRC_RST_DEV_L_CPU, TEGRA_CLK_RESET_BASE + CRC_RST_DEV_L_CLR);
}
/* stop all internal and external clocks to the main CPU complex */
static void stop_maincomplex_clocks(int num_cores)
{
u32 reg;
int i;
reg = readl(TEGRA_CLK_RESET_BASE + CRC_CLK_CPU_CMPLX);
for (i = 0; i < num_cores; i++)
reg |= 0x1 << (8 + i);
writel(reg, TEGRA_CLK_RESET_BASE + CRC_CLK_CPU_CMPLX);
reg = readl(TEGRA_CLK_RESET_BASE + CRC_CLK_OUT_ENB_L);
reg &= ~CRC_CLK_OUT_ENB_L_CPU;
writel(reg, TEGRA_CLK_RESET_BASE + CRC_CLK_OUT_ENB_L);
}
struct pll_config {
u16 divn;
u16 divm;
u16 divp;
u16 cpcon;
};
static struct pll_config pllx_config_table[][4] = {
{
{1000, 13, 0, 12}, /* OSC 13.0 MHz */
{625, 12, 0, 8 }, /* OSC 19.2 MHz */
{1000, 12, 0, 12}, /* OSC 12.0 MHz */
{1000, 26, 0, 12}, /* OSC 26.0 MHz */
}, /* TEGRA 20 */
};
static void init_pllx(void)
{
struct pll_config *conf;
enum tegra_chiptype chiptype;
u8 osc_freq;
u32 reg;
/* If PLLX is already enabled, just return */
if (readl(TEGRA_CLK_RESET_BASE + CRC_PLLX_BASE) & CRC_PLLX_BASE_ENABLE)
return;
chiptype = tegra_get_chiptype();
if (chiptype < 0)
BUG();
osc_freq = (readl(TEGRA_CLK_RESET_BASE + CRC_OSC_CTRL) &
CRC_OSC_CTRL_OSC_FREQ_MASK) >> CRC_OSC_CTRL_OSC_FREQ_SHIFT;
conf = &pllx_config_table[chiptype][osc_freq];
/* set PLL bypass and frequency parameters */
reg = CRC_PLLX_BASE_BYPASS;
reg |= (conf->divm << CRC_PLLX_BASE_DIVM_SHIFT) &
CRC_PLLX_BASE_DIVM_MASK;
reg |= (conf->divn << CRC_PLLX_BASE_DIVN_SHIFT) &
CRC_PLLX_BASE_DIVN_MASK;
reg |= (conf->divp << CRC_PLLX_BASE_DIVP_SHIFT) &
CRC_PLLX_BASE_DIVP_MASK;
writel(reg, TEGRA_CLK_RESET_BASE + CRC_PLLX_BASE);
/* set chargepump parameters */
reg = (conf->cpcon << CRC_PLLX_MISC_CPCON_SHIFT) &
CRC_PLLX_MISC_CPCON_MASK;
if (conf->divn > 600)
reg |= CRC_PLLX_MISC_DCCON;
writel(reg, TEGRA_CLK_RESET_BASE + CRC_PLLX_MISC);
/* enable PLL and disable bypass */
reg = readl(TEGRA_CLK_RESET_BASE + CRC_PLLX_BASE);
reg |= CRC_PLLX_BASE_ENABLE;
reg &= ~CRC_PLLX_BASE_BYPASS;
writel(reg, TEGRA_CLK_RESET_BASE + CRC_PLLX_BASE);
/* enable PLL lock */
reg = readl(TEGRA_CLK_RESET_BASE + CRC_PLLX_MISC);
reg |= CRC_PLLX_MISC_LOCK_ENABLE;
writel(reg, TEGRA_CLK_RESET_BASE + CRC_PLLX_MISC);
}
/* start internal and external clocks to core 0 of the main CPU complex */
static void start_cpu0_clocks(void)
{
u32 reg;
/* setup PLLX */
init_pllx();
/* setup super CLK */
writel(CRC_SCLK_BURST_POLICY_SYS_STATE_RUN <<
CRC_SCLK_BURST_POLICY_SYS_STATE_SHIFT,
TEGRA_CLK_RESET_BASE + CRC_SCLK_BURST_POLICY);
writel(CRC_SUPER_SDIV_ENB, TEGRA_CLK_RESET_BASE + CRC_SUPER_SCLK_DIV);
/* deassert clock stop for cpu 0 */
reg = readl(TEGRA_CLK_RESET_BASE + CRC_CLK_CPU_CMPLX);
reg &= ~CRC_CLK_CPU_CMPLX_CPU0_CLK_STP;
writel(reg, TEGRA_CLK_RESET_BASE + CRC_CLK_CPU_CMPLX);
/* enable main CPU complex clock */
reg = readl(TEGRA_CLK_RESET_BASE + CRC_CLK_OUT_ENB_L);
reg |= CRC_CLK_OUT_ENB_L_CPU;
writel(reg, TEGRA_CLK_RESET_BASE + CRC_CLK_OUT_ENB_L);
}
static void maincomplex_powerup(void)
{
u32 reg;
if (!(readl(TEGRA_PMC_BASE + PMC_PWRGATE_STATUS) &
PMC_PWRGATE_STATUS_CPU)) {
writel(PMC_PWRGATE_TOGGLE_START | PMC_PWRGATE_TOGGLE_PARTID_CPU,
TEGRA_PMC_BASE + PMC_PWRGATE_TOGGLE);
while (!(readl(TEGRA_PMC_BASE + PMC_PWRGATE_STATUS) &
PMC_PWRGATE_STATUS_CPU));
reg = readl(TEGRA_PMC_BASE + PMC_REMOVE_CLAMPING_CMD);
reg |= PMC_REMOVE_CLAMPING_CMD_CPU;
writel(reg, TEGRA_PMC_BASE + PMC_REMOVE_CLAMPING_CMD);
}
}
void barebox_arm_reset_vector(void)
{
int num_cores;
/* minimal initialization, OK for both ARMv4 and ARMv7 */
tegra_cpu_lowlevel_setup();
/*
* If we are already running on the main CPU complex jump straight
* to the maincomplex entry point.
*/
if (tegra_cpu_is_maincomplex())
tegra_maincomplex_entry();
/* get the number of cores in the main CPU complex of the current SoC */
num_cores = tegra_get_num_cores();
if (!num_cores)
BUG();
/* bring down main CPU complex (this may be a warm boot) */
enable_maincomplex_powerrail();
assert_maincomplex_reset(num_cores);
stop_maincomplex_clocks(num_cores);
/* set start address for the main CPU complex processors */
writel(barebox_arm_head, TEGRA_EXCEPTION_VECTORS_BASE + 0x100);
/* bring up main CPU complex */
start_cpu0_clocks();
maincomplex_powerup();
deassert_cpu0_reset();
/* assert AVP reset to stop execution here */
writel(CRC_RST_DEV_L_COP, TEGRA_CLK_RESET_BASE + CRC_RST_DEV_L_SET);
unreachable();
}
