/*
* CPU complex suspend & resume functions for Tegra SoCs
*
* Copyright (c) 2009-2012, NVIDIA Corporation. All rights reserved.
*
* 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 <linux/kernel.h>
#include <linux/spinlock.h>
#include <linux/io.h>
#include <linux/cpumask.h>
#include <linux/delay.h>
#include <linux/cpu_pm.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <asm/smp_plat.h>
#include <asm/cacheflush.h>
#include <asm/suspend.h>
#include <asm/idmap.h>
#include <asm/proc-fns.h>
#include <asm/tlbflush.h>
#include "iomap.h"
#include "reset.h"
#include "flowctrl.h"
#include "sleep.h"
#include "tegra_cpu_car.h"
#define TEGRA_POWER_CPU_PWRREQ_OE (1 << 16) /* CPU pwr req enable */
#define PMC_CTRL 0x0
#define PMC_CPUPWRGOOD_TIMER 0xc8
#define PMC_CPUPWROFF_TIMER 0xcc
#ifdef CONFIG_PM_SLEEP
static unsigned int g_diag_reg;
static DEFINE_SPINLOCK(tegra_lp2_lock);
static void __iomem *pmc = IO_ADDRESS(TEGRA_PMC_BASE);
static struct clk *tegra_pclk;
void (*tegra_tear_down_cpu)(void);
void save_cpu_arch_register(void)
{
/* read diagnostic register */
asm("mrc p15, 0, %0, c15, c0, 1" : "=r"(g_diag_reg) : : "cc");
return;
}
void restore_cpu_arch_register(void)
{
/* write diagnostic register */
asm("mcr p15, 0, %0, c15, c0, 1" : : "r"(g_diag_reg) : "cc");
return;
}
static void set_power_timers(unsigned long us_on, unsigned long us_off)
{
unsigned long long ticks;
unsigned long long pclk;
unsigned long rate;
static unsigned long tegra_last_pclk;
if (tegra_pclk == NULL) {
tegra_pclk = clk_get_sys(NULL, "pclk");
WARN_ON(IS_ERR(tegra_pclk));
}
rate = clk_get_rate(tegra_pclk);
if (WARN_ON_ONCE(rate <= 0))
pclk = 100000000;
else
pclk = rate;
if ((rate != tegra_last_pclk)) {
ticks = (us_on * pclk) + 999999ull;
do_div(ticks, 1000000);
writel((unsigned long)ticks, pmc + PMC_CPUPWRGOOD_TIMER);
ticks = (us_off * pclk) + 999999ull;
do_div(ticks, 1000000);
writel((unsigned long)ticks, pmc + PMC_CPUPWROFF_TIMER);
wmb();
}
tegra_last_pclk = pclk;
}
/*
* restore_cpu_complex
*
* restores cpu clock setting, clears flow controller
*
* Always called on CPU 0.
*/
static void restore_cpu_complex(void)
{
int cpu = smp_processor_id();
BUG_ON(cpu != 0);
#ifdef CONFIG_SMP
cpu = cpu_logical_map(cpu);
#endif
/* Restore the CPU clock settings */
tegra_cpu_clock_resume();
flowctrl_cpu_suspend_exit(cpu);
restore_cpu_arch_register();
}
/*
* suspend_cpu_complex
*
* saves pll state for use by restart_plls, prepares flow controller for
* transition to suspend state
*
* Must always be called on cpu 0.
*/
static void suspend_cpu_complex(void)
{
int cpu = smp_processor_id();
BUG_ON(cpu != 0);
#ifdef CONFIG_SMP
cpu = cpu_logical_map(cpu);
#endif
/* Save the CPU clock settings */
tegra_cpu_clock_suspend();
flowctrl_cpu_suspend_enter(cpu);
save_cpu_arch_register();
}
void __cpuinit tegra_clear_cpu_in_lp2(int phy_cpu_id)
{
u32 *cpu_in_lp2 = tegra_cpu_lp2_mask;
spin_lock(&tegra_lp2_lock);
BUG_ON(!(*cpu_in_lp2 & BIT(phy_cpu_id)));
*cpu_in_lp2 &= ~BIT(phy_cpu_id);
spin_unlock(&tegra_lp2_lock);
}
bool __cpuinit tegra_set_cpu_in_lp2(int phy_cpu_id)
{
bool last_cpu = false;
cpumask_t *cpu_lp2_mask = tegra_cpu_lp2_mask;
u32 *cpu_in_lp2 = tegra_cpu_lp2_mask;
spin_lock(&tegra_lp2_lock);
BUG_ON((*cpu_in_lp2 & BIT(phy_cpu_id)));
*cpu_in_lp2 |= BIT(phy_cpu_id);
if ((phy_cpu_id == 0) && cpumask_equal(cpu_lp2_mask, cpu_online_mask))
last_cpu = true;
spin_unlock(&tegra_lp2_lock);
return last_cpu;
}
static int tegra_sleep_cpu(unsigned long v2p)
{
/* Switch to the identity mapping. */
cpu_switch_mm(idmap_pgd, &init_mm);
/* Flush the TLB. */
local_flush_tlb_all();
tegra_sleep_cpu_finish(v2p);
/* should never here */
BUG();
return 0;
}
void tegra_idle_lp2_last(u32 cpu_on_time, u32 cpu_off_time)
{
u32 mode;
/* Only the last cpu down does the final suspend steps */
mode = readl(pmc + PMC_CTRL);
mode |= TEGRA_POWER_CPU_PWRREQ_OE;
writel(mode, pmc + PMC_CTRL);
set_power_timers(cpu_on_time, cpu_off_time);
cpu_cluster_pm_enter();
suspend_cpu_complex();
cpu_suspend(PHYS_OFFSET - PAGE_OFFSET, &tegra_sleep_cpu);
restore_cpu_complex();
cpu_cluster_pm_exit();
}
#endif
