/*
* 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/init.h>
#include <linux/errno.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/jiffies.h>
#include <linux/smp.h>
#include <linux/io.h>
#include <asm/cacheflush.h>
#include <asm/hardware/gic.h>
#include <asm/mach-types.h>
#include <asm/smp_scu.h>
#include <asm/smp_plat.h>
#include <mach/powergate.h>
#include "fuse.h"
#include "flowctrl.h"
#include "reset.h"
#include "tegra_cpu_car.h"
#include "common.h"
#include "iomap.h"
extern void tegra_secondary_startup(void);
static cpumask_t tegra_cpu_init_mask;
static void __iomem *scu_base = IO_ADDRESS(TEGRA_ARM_PERIF_BASE);
#define EVP_CPU_RESET_VECTOR \
(IO_ADDRESS(TEGRA_EXCEPTION_VECTORS_BASE) + 0x100)
static void __cpuinit tegra_secondary_init(unsigned int cpu)
{
/*
* if any interrupts are already enabled for the primary
* core (e.g. timer irq), then they will not have been enabled
* for us: do so
*/
gic_secondary_init(0);
cpumask_set_cpu(cpu, &tegra_cpu_init_mask);
}
static int tegra20_power_up_cpu(unsigned int cpu)
{
/* Enable the CPU clock. */
tegra_enable_cpu_clock(cpu);
/* Clear flow controller CSR. */
flowctrl_write_cpu_csr(cpu, 0);
return 0;
}
static int tegra30_power_up_cpu(unsigned int cpu)
{
int ret, pwrgateid;
unsigned long timeout;
pwrgateid = tegra_cpu_powergate_id(cpu);
if (pwrgateid < 0)
return pwrgateid;
/*
* 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_power_up_cpu()
* next time around.
*/
if (cpumask_test_cpu(cpu, &tegra_cpu_init_mask)) {
timeout = jiffies + 5*HZ;
do {
if (!tegra_powergate_is_powered(pwrgateid))
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_powergate_is_powered(pwrgateid)) {
ret = tegra_powergate_power_on(pwrgateid);
if (ret)
return ret;
/* Wait for the power to come up. */
timeout = jiffies + 10*HZ;
while (tegra_powergate_is_powered(pwrgateid)) {
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_powergate_remove_clamping(pwrgateid);
udelay(10);
/* Clear flow controller CSR. */
flowctrl_write_cpu_csr(cpu, 0);
return 0;
}
static int __cpuinit tegra_boot_secondary(unsigned int cpu, struct task_struct *idle)
{
int status;
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);
switch (tegra_chip_id) {
case TEGRA20:
status = tegra20_power_up_cpu(cpu);
break;
case TEGRA30:
status = tegra30_power_up_cpu(cpu);
break;
default:
status = -EINVAL;
break;
}
if (status)
goto done;
/* Take the CPU out of reset. */
tegra_cpu_out_of_reset(cpu);
done:
return status;
}
/*
* Initialise the CPU possible map early - this describes the CPUs
* which may be present or become present in the system.
*/
static void __init tegra_smp_init_cpus(void)
{
unsigned int i, ncores = scu_get_core_count(scu_base);
if (ncores > nr_cpu_ids) {
pr_warn("SMP: %u cores greater than maximum (%u), clipping\n",
ncores, nr_cpu_ids);
ncores = nr_cpu_ids;
}
for (i = 0; i < ncores; i++)
set_cpu_possible(i, true);
set_smp_cross_call(gic_raise_softirq);
}
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);
scu_enable(scu_base);
}
struct smp_operations tegra_smp_ops __initdata = {
.smp_init_cpus = tegra_smp_init_cpus,
.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,
.cpu_disable = tegra_cpu_disable,
#endif
};
