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// SPDX-License-Identifier: GPL-2.0
/*
* SMP support for SoCs with APMU
*
* Copyright (C) 2014 Renesas Electronics Corporation
* Copyright (C) 2013 Magnus Damm
*/
#include <linux/cpu_pm.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/smp.h>
#include <linux/suspend.h>
#include <linux/threads.h>
#include <asm/cacheflush.h>
#include <asm/cp15.h>
#include <asm/proc-fns.h>
#include <asm/smp_plat.h>
#include <asm/suspend.h>
#include "common.h"
#include "rcar-gen2.h"
static struct {
void __iomem *iomem;
int bit;
} apmu_cpus[NR_CPUS];
#define WUPCR_OFFS 0x10 /* Wake Up Control Register */
#define PSTR_OFFS 0x40 /* Power Status Register */
#define CPUNCR_OFFS(n) (0x100 + (0x10 * (n)))
/* CPUn Power Status Control Register */
#define DBGRCR_OFFS 0x180 /* Debug Resource Reset Control Reg. */
/* Power Status Register */
#define CPUNST(r, n) (((r) >> (n * 4)) & 3) /* CPUn Status Bit */
#define CPUST_RUN 0 /* Run Mode */
#define CPUST_STANDBY 3 /* CoreStandby Mode */
/* Debug Resource Reset Control Register */
#define DBGCPUREN BIT(24) /* CPU Other Reset Request Enable */
#define DBGCPUNREN(n) BIT((n) + 20) /* CPUn Reset Request Enable */
#define DBGCPUPREN BIT(19) /* CPU Peripheral Reset Req. Enable */
static int __maybe_unused apmu_power_on(void __iomem *p, int bit)
{
/* request power on */
writel_relaxed(BIT(bit), p + WUPCR_OFFS);
/* wait for APMU to finish */
while (readl_relaxed(p + WUPCR_OFFS) != 0)
;
return 0;
}
static int __maybe_unused apmu_power_off(void __iomem *p, int bit)
{
/* request Core Standby for next WFI */
writel_relaxed(3, p + CPUNCR_OFFS(bit));
return 0;
}
static int __maybe_unused apmu_power_off_poll(void __iomem *p, int bit)
{
int k;
for (k = 0; k < 1000; k++) {
if (CPUNST(readl_relaxed(p + PSTR_OFFS), bit) == CPUST_STANDBY)
return 1;
mdelay(1);
}
return 0;
}
static int __maybe_unused apmu_wrap(int cpu, int (*fn)(void __iomem *p, int cpu))
{
void __iomem *p = apmu_cpus[cpu].iomem;
return p ? fn(p, apmu_cpus[cpu].bit) : -EINVAL;
}
#if defined(CONFIG_HOTPLUG_CPU) || defined(CONFIG_SUSPEND)
/* nicked from arch/arm/mach-exynos/hotplug.c */
static inline void cpu_enter_lowpower_a15(void)
{
unsigned int v;
asm volatile(
" mrc p15, 0, %0, c1, c0, 0\n"
" bic %0, %0, %1\n"
" mcr p15, 0, %0, c1, c0, 0\n"
: "=&r" (v)
: "Ir" (CR_C)
: "cc");
flush_cache_louis();
asm volatile(
/*
* Turn off coherency
*/
" mrc p15, 0, %0, c1, c0, 1\n"
" bic %0, %0, %1\n"
" mcr p15, 0, %0, c1, c0, 1\n"
: "=&r" (v)
: "Ir" (0x40)
: "cc");
isb();
dsb();
}
static void shmobile_smp_apmu_cpu_shutdown(unsigned int cpu)
{
/* Select next sleep mode using the APMU */
apmu_wrap(cpu, apmu_power_off);
/* Do ARM specific CPU shutdown */
cpu_enter_lowpower_a15();
}
#endif
#if defined(CONFIG_HOTPLUG_CPU)
static void shmobile_smp_apmu_cpu_die(unsigned int cpu)
{
/* For this particular CPU deregister boot vector */
shmobile_smp_hook(cpu, 0, 0);
/* Shutdown CPU core */
shmobile_smp_apmu_cpu_shutdown(cpu);
/* jump to shared mach-shmobile sleep / reset code */
shmobile_smp_sleep();
}
static int shmobile_smp_apmu_cpu_kill(unsigned int cpu)
{
return apmu_wrap(cpu, apmu_power_off_poll);
}
#endif
#if defined(CONFIG_SUSPEND)
static int shmobile_smp_apmu_do_suspend(unsigned long cpu)
{
shmobile_smp_hook(cpu, __pa_symbol(cpu_resume), 0);
shmobile_smp_apmu_cpu_shutdown(cpu);
cpu_do_idle(); /* WFI selects Core Standby */
return 1;
}
static inline void cpu_leave_lowpower(void)
{
unsigned int v;
asm volatile("mrc p15, 0, %0, c1, c0, 0\n"
" orr %0, %0, %1\n"
" mcr p15, 0, %0, c1, c0, 0\n"
" mrc p15, 0, %0, c1, c0, 1\n"
" orr %0, %0, %2\n"
" mcr p15, 0, %0, c1, c0, 1\n"
: "=&r" (v)
: "Ir" (CR_C), "Ir" (0x40)
: "cc");
}
static int shmobile_smp_apmu_enter_suspend(suspend_state_t state)
{
cpu_suspend(smp_processor_id(), shmobile_smp_apmu_do_suspend);
cpu_leave_lowpower();
return 0;
}
void __init shmobile_smp_apmu_suspend_init(void)
{
shmobile_suspend_ops.enter = shmobile_smp_apmu_enter_suspend;
}
#endif
#ifdef CONFIG_SMP
static void apmu_init_cpu(struct resource *res, int cpu, int bit)
{
u32 x;
if ((cpu >= ARRAY_SIZE(apmu_cpus)) || apmu_cpus[cpu].iomem)
return;
apmu_cpus[cpu].iomem = ioremap(res->start, resource_size(res));
apmu_cpus[cpu].bit = bit;
pr_debug("apmu ioremap %d %d %pr\n", cpu, bit, res);
/* Setup for debug mode */
x = readl(apmu_cpus[cpu].iomem + DBGRCR_OFFS);
x |= DBGCPUREN | DBGCPUNREN(bit) | DBGCPUPREN;
writel(x, apmu_cpus[cpu].iomem + DBGRCR_OFFS);
}
static const struct of_device_id apmu_ids[] = {
{ .compatible = "renesas,apmu" },
{ /*sentinel*/ }
};
static void apmu_parse_dt(void (*fn)(struct resource *res, int cpu, int bit))
{
struct device_node *np_apmu, *np_cpu;
struct resource res;
int bit, index;
for_each_matching_node(np_apmu, apmu_ids) {
/* only enable the cluster that includes the boot CPU */
bool is_allowed = false;
for (bit = 0; bit < CONFIG_NR_CPUS; bit++) {
np_cpu = of_parse_phandle(np_apmu, "cpus", bit);
if (!np_cpu)
break;
if (of_cpu_node_to_id(np_cpu) == 0) {
is_allowed = true;
of_node_put(np_cpu);
break;
}
of_node_put(np_cpu);
}
if (!is_allowed)
continue;
for (bit = 0; bit < CONFIG_NR_CPUS; bit++) {
np_cpu = of_parse_phandle(np_apmu, "cpus", bit);
if (!np_cpu)
break;
index = of_cpu_node_to_id(np_cpu);
if ((index >= 0) &&
!of_address_to_resource(np_apmu, 0, &res))
fn(&res, index, bit);
of_node_put(np_cpu);
}
}
}
static void __init shmobile_smp_apmu_setup_boot(void)
{
/* install boot code shared by all CPUs */
shmobile_boot_fn = __pa_symbol(shmobile_smp_boot);
shmobile_boot_fn_gen2 = shmobile_boot_fn;
}
static int shmobile_smp_apmu_boot_secondary(unsigned int cpu,
struct task_struct *idle)
{
/* For this particular CPU register boot vector */
shmobile_smp_hook(cpu, __pa_symbol(shmobile_boot_apmu), 0);
return apmu_wrap(cpu, apmu_power_on);
}
static void __init shmobile_smp_apmu_prepare_cpus_dt(unsigned int max_cpus)
{
shmobile_smp_apmu_setup_boot();
apmu_parse_dt(apmu_init_cpu);
rcar_gen2_pm_init();
}
static struct smp_operations apmu_smp_ops __initdata = {
.smp_prepare_cpus = shmobile_smp_apmu_prepare_cpus_dt,
.smp_boot_secondary = shmobile_smp_apmu_boot_secondary,
#ifdef CONFIG_HOTPLUG_CPU
.cpu_can_disable = shmobile_smp_cpu_can_disable,
.cpu_die = shmobile_smp_apmu_cpu_die,
.cpu_kill = shmobile_smp_apmu_cpu_kill,
#endif
};
CPU_METHOD_OF_DECLARE(shmobile_smp_apmu, "renesas,apmu", &apmu_smp_ops);
#endif /* CONFIG_SMP */
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