diff options
Diffstat (limited to 'arch/arm/mach-shmobile/platsmp-apmu.c')
| -rw-r--r-- | arch/arm/mach-shmobile/platsmp-apmu.c | 194 |
1 files changed, 194 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 00000000000..8cb641c00fd --- /dev/null +++ b/arch/arm/mach-shmobile/platsmp-apmu.c @@ -0,0 +1,194 @@ +/* + * SMP support for SoCs with APMU + * + * Copyright (C) 2013 Magnus Damm + * + * 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/delay.h> +#include <linux/init.h> +#include <linux/io.h> +#include <linux/ioport.h> +#include <linux/of_address.h> +#include <linux/smp.h> +#include <asm/cacheflush.h> +#include <asm/cp15.h> +#include <asm/smp_plat.h> +#include <mach/common.h> + +static struct { + void __iomem *iomem; + int bit; +} apmu_cpus[CONFIG_NR_CPUS]; + +#define WUPCR_OFFS 0x10 +#define PSTR_OFFS 0x40 +#define CPUNCR_OFFS(n) (0x100 + (0x10 * (n))) + +static int 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 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 apmu_power_off_poll(void __iomem *p, int bit) +{ + int k; + + for (k = 0; k < 1000; k++) { + if (((readl_relaxed(p + PSTR_OFFS) >> (bit * 4)) & 0x03) == 3) + return 1; + + mdelay(1); + } + + return 0; +} + +static int 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; +} + +static void apmu_init_cpu(struct resource *res, int cpu, int bit) +{ + if (apmu_cpus[cpu].iomem) + return; + + apmu_cpus[cpu].iomem = ioremap_nocache(res->start, resource_size(res)); + apmu_cpus[cpu].bit = bit; + + pr_debug("apmu ioremap %d %d %pr\n", cpu, bit, res); +} + +static struct { + struct resource iomem; + int cpus[4]; +} apmu_config[] = { + { + .iomem = DEFINE_RES_MEM(0xe6152000, 0x88), + .cpus = { 0, 1, 2, 3 }, + }, + { + .iomem = DEFINE_RES_MEM(0xe6151000, 0x88), + .cpus = { 0x100, 0x101, 0x102, 0x103 }, + } +}; + +static void apmu_parse_cfg(void (*fn)(struct resource *res, int cpu, int bit)) +{ + u32 id; + int k; + int bit, index; + bool is_allowed; + + for (k = 0; k < ARRAY_SIZE(apmu_config); k++) { + /* only enable the cluster that includes the boot CPU */ + is_allowed = false; + for (bit = 0; bit < ARRAY_SIZE(apmu_config[k].cpus); bit++) { + id = apmu_config[k].cpus[bit]; + if (id >= 0) { + if (id == cpu_logical_map(0)) + is_allowed = true; + } + } + if (!is_allowed) + continue; + + for (bit = 0; bit < ARRAY_SIZE(apmu_config[k].cpus); bit++) { + id = apmu_config[k].cpus[bit]; + if (id >= 0) { + index = get_logical_index(id); + if (index >= 0) + fn(&apmu_config[k].iomem, index, bit); + } + } + } +} + +void __init shmobile_smp_apmu_prepare_cpus(unsigned int max_cpus) +{ + /* install boot code shared by all CPUs */ + shmobile_boot_fn = virt_to_phys(shmobile_smp_boot); + shmobile_boot_arg = MPIDR_HWID_BITMASK; + + /* perform per-cpu setup */ + apmu_parse_cfg(apmu_init_cpu); +} + +int shmobile_smp_apmu_boot_secondary(unsigned int cpu, struct task_struct *idle) +{ + /* For this particular CPU register boot vector */ + shmobile_smp_hook(cpu, virt_to_phys(shmobile_invalidate_start), 0); + + return apmu_wrap(cpu, apmu_power_on); +} + +#ifdef CONFIG_HOTPLUG_CPU +/* 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(); +} + +void shmobile_smp_apmu_cpu_die(unsigned int cpu) +{ + /* For this particular CPU deregister boot vector */ + shmobile_smp_hook(cpu, 0, 0); + + /* Select next sleep mode using the APMU */ + apmu_wrap(cpu, apmu_power_off); + + /* Do ARM specific CPU shutdown */ + cpu_enter_lowpower_a15(); + + /* jump to shared mach-shmobile sleep / reset code */ + shmobile_smp_sleep(); +} + +int shmobile_smp_apmu_cpu_kill(unsigned int cpu) +{ + return apmu_wrap(cpu, apmu_power_off_poll); +} +#endif |