diff options
Diffstat (limited to 'arch/arm/mach-npcm/platsmp.c')
-rw-r--r-- | arch/arm/mach-npcm/platsmp.c | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/arch/arm/mach-npcm/platsmp.c b/arch/arm/mach-npcm/platsmp.c new file mode 100644 index 0000000..21633c7 --- /dev/null +++ b/arch/arm/mach-npcm/platsmp.c @@ -0,0 +1,81 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (c) 2018 Nuvoton Technology corporation. +// Copyright 2018 Google, Inc. + +#define pr_fmt(fmt) "nuvoton,npcm7xx-smp: " fmt + +#include <linux/delay.h> +#include <linux/device.h> +#include <linux/smp.h> +#include <linux/io.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/of_platform.h> +#include <linux/of_address.h> +#include <asm/cacheflush.h> +#include <asm/smp.h> +#include <asm/smp_plat.h> +#include <asm/smp_scu.h> + +#define NPCM7XX_SCRPAD_REG 0x13c + +extern void npcm7xx_secondary_startup(void); + +static int npcm7xx_smp_boot_secondary(unsigned int cpu, + struct task_struct *idle) +{ + struct device_node *gcr_np; + void __iomem *gcr_base; + int ret = 0; + + gcr_np = of_find_compatible_node(NULL, NULL, "nuvoton,npcm750-gcr"); + if (!gcr_np) { + pr_err("no gcr device node\n"); + ret = -ENODEV; + goto out; + } + gcr_base = of_iomap(gcr_np, 0); + if (!gcr_base) { + pr_err("could not iomap gcr"); + ret = -ENOMEM; + goto out; + } + + /* give boot ROM kernel start address. */ + iowrite32(__pa_symbol(npcm7xx_secondary_startup), gcr_base + + NPCM7XX_SCRPAD_REG); + /* make sure the previous write is seen by all observers. */ + dsb_sev(); + + iounmap(gcr_base); +out: + return ret; +} + +static void __init npcm7xx_smp_prepare_cpus(unsigned int max_cpus) +{ + struct device_node *scu_np; + void __iomem *scu_base; + + scu_np = of_find_compatible_node(NULL, NULL, "arm,cortex-a9-scu"); + if (!scu_np) { + pr_err("no scu device node\n"); + return; + } + scu_base = of_iomap(scu_np, 0); + if (!scu_base) { + pr_err("could not iomap scu"); + return; + } + + scu_enable(scu_base); + + iounmap(scu_base); +} + +static struct smp_operations npcm7xx_smp_ops __initdata = { + .smp_prepare_cpus = npcm7xx_smp_prepare_cpus, + .smp_boot_secondary = npcm7xx_smp_boot_secondary, +}; + +CPU_METHOD_OF_DECLARE(npcm7xx_smp, "nuvoton,npcm750-smp", &npcm7xx_smp_ops); |