summaryrefslogtreecommitdiffstats
path: root/arch/arm/mach-shmobile/platsmp-apmu.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/arm/mach-shmobile/platsmp-apmu.c')
-rw-r--r--arch/arm/mach-shmobile/platsmp-apmu.c282
1 files changed, 282 insertions, 0 deletions
diff --git a/arch/arm/mach-shmobile/platsmp-apmu.c b/arch/arm/mach-shmobile/platsmp-apmu.c
new file mode 100644
index 0000000000..ec6f421c0f
--- /dev/null
+++ b/arch/arm/mach-shmobile/platsmp-apmu.c
@@ -0,0 +1,282 @@
+// 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 */