/*
* linux/arch/arm/mach-tegra/platsmp.c
*
* Copyright (C) 2002 ARM Ltd.
* All Rights Reserved
*
* Copyright (C) 2009 Palm
* 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 version 2 as
* published by the Free Software Foundation.
*/
#include <linux/clk/tegra.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/jiffies.h>
#include <linux/smp.h>
#include <soc/tegra/fuse.h>
#include <soc/tegra/pmc.h>
#include <asm/cacheflush.h>
#include <asm/mach-types.h>
#include <asm/smp_plat.h>
#include <asm/smp_scu.h>
#include "common.h"
#include "flowctrl.h"
#include "iomap.h"
#include "reset.h"
static cpumask_t tegra_cpu_init_mask;
static void tegra_secondary_init(unsigned int cpu)
{
cpumask_set_cpu(cpu, &tegra_cpu_init_mask);
}
static int tegra20_boot_secondary(unsigned int cpu, struct task_struct *idle)
{
cpu = cpu_logical_map(cpu);
/*
* Force the CPU into reset. The CPU must remain in reset when
* the flow controller state is cleared (which will cause the
* flow controller to stop driving reset if the CPU has been
* power-gated via the flow controller). This will have no
* effect on first boot of the CPU since it should already be
* in reset.
*/
tegra_put_cpu_in_reset(cpu);
/*
* Unhalt the CPU. If the flow controller was used to
* power-gate the CPU this will cause the flow controller to
* stop driving reset. The CPU will remain in reset because the
* clock and reset block is now driving reset.
*/
flowctrl_write_cpu_halt(cpu, 0);
tegra_enable_cpu_clock(cpu);
flowctrl_write_cpu_csr(cpu, 0); /* Clear flow controller CSR. */
tegra_cpu_out_of_reset(cpu);
return 0;
}
static int tegra30_boot_secondary(unsigned int cpu, struct task_struct *idle)
{
int ret;
unsigned long timeout;
cpu = cpu_logical_map(cpu);
tegra_put_cpu_in_reset(cpu);
flowctrl_write_cpu_halt(cpu, 0);
/*
* The power up sequence of cold boot CPU and warm boot CPU
* was different.
*
* For warm boot CPU that was resumed from CPU hotplug, the
* power will be resumed automatically after un-halting the
* flow controller of the warm boot CPU. We need to wait for
* the confirmaiton that the CPU is powered then removing
* the IO clamps.
* For cold boot CPU, do not wait. After the cold boot CPU be
* booted, it will run to tegra_secondary_init() and set
* tegra_cpu_init_mask which influences what tegra30_boot_secondary()
* next time around.
*/
if (cpumask_test_cpu(cpu, &tegra_cpu_init_mask)) {
timeout = jiffies + msecs_to_jiffies(50);
do {
if (tegra_pmc_cpu_is_powered(cpu))
goto remove_clamps;
udelay(10);
} while (time_before(jiffies, timeout));
}
/*
* The power status of the cold boot CPU is power gated as
* default. To power up the cold boot CPU, the power should
* be un-gated by un-toggling the power gate register
* manually.
*/
if (!tegra_pmc_cpu_is_powered(cpu)) {
ret = tegra_pmc_cpu_power_on(cpu);
if (ret)
return ret;
/* Wait for the power to come up. */
timeout = jiffies + msecs_to_jiffies(100);
while (!tegra_pmc_cpu_is_powered(cpu)) {
if (time_after(jiffies, timeout))
return -ETIMEDOUT;
udelay(10);
}
}
remove_clamps:
/* CPU partition is powered. Enable the CPU clock. */
tegra_enable_cpu_clock(cpu);
udelay(10);
/* Remove I/O clamps. */
ret = tegra_pmc_cpu_remove_clamping(cpu);
if (ret)
return ret;
udelay(10);
flowctrl_write_cpu_csr(cpu, 0); /* Clear flow controller CSR. */
tegra_cpu_out_of_reset(cpu);
return 0;
}
static int tegra114_boot_secondary(unsigned int cpu, struct task_struct *idle)
{
int ret = 0;
cpu = cpu_logical_map(cpu);
if (cpumask_test_cpu(cpu, &tegra_cpu_init_mask)) {
/*
* Warm boot flow
* The flow controller in charge of the power state and
* control for each CPU.
*/
/* set SCLK as event trigger for flow controller */
flowctrl_write_cpu_csr(cpu, 1);
flowctrl_write_cpu_halt(cpu,
FLOW_CTRL_WAITEVENT | FLOW_CTRL_SCLK_RESUME);
} else {
/*
* Cold boot flow
* The CPU is powered up by toggling PMC directly. It will
* also initial power state in flow controller. After that,
* the CPU's power state is maintained by flow controller.
*/
ret = tegra_pmc_cpu_power_on(cpu);
}
return ret;
}
static int tegra_boot_secondary(unsigned int cpu,
struct task_struct *idle)
{
if (IS_ENABLED(CONFIG_ARCH_TEGRA_2x_SOC) && tegra_get_chip_id() == TEGRA20)
return tegra20_boot_secondary(cpu, idle);
if (IS_ENABLED(CONFIG_ARCH_TEGRA_3x_SOC) && tegra_get_chip_id() == TEGRA30)
return tegra30_boot_secondary(cpu, idle);
if (IS_ENABLED(CONFIG_ARCH_TEGRA_114_SOC) && tegra_get_chip_id() == TEGRA114)
return tegra114_boot_secondary(cpu, idle);
if (IS_ENABLED(CONFIG_ARCH_TEGRA_124_SOC) && tegra_get_chip_id() == TEGRA124)
return tegra114_boot_secondary(cpu, idle);
return -EINVAL;
}
static void __init tegra_smp_prepare_cpus(unsigned int max_cpus)
{
/* Always mark the boot CPU (CPU0) as initialized. */
cpumask_set_cpu(0, &tegra_cpu_init_mask);
if (scu_a9_has_base())
scu_enable(IO_ADDRESS(scu_a9_get_base()));
}
struct smp_operations tegra_smp_ops __initdata = {
.smp_prepare_cpus = tegra_smp_prepare_cpus,
.smp_secondary_init = tegra_secondary_init,
.smp_boot_secondary = tegra_boot_secondary,
#ifdef CONFIG_HOTPLUG_CPU
.cpu_kill = tegra_cpu_kill,
.cpu_die = tegra_cpu_die,
#endif
};
