linux-next/arch/arm/mach-mvebu/pmsu.c

/*
 * Power Management Service Unit(PMSU) support for Armada 370/XP platforms.
 *
 * Copyright (C) 2012 Marvell
 *
 * Yehuda Yitschak <yehuday@marvell.com>
 * Gregory Clement <gregory.clement@free-electrons.com>
 * Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
 *
 * This file is licensed under the terms of the GNU General Public
 * License version 2.  This program is licensed "as is" without any
 * warranty of any kind, whether express or implied.
 *
 * The Armada 370 and Armada XP SOCs have a power management service
 * unit which is responsible for powering down and waking up CPUs and
 * other SOC units
 */

#define pr_fmt(fmt) "mvebu-pmsu: " fmt

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/of_address.h>
#include <linux/io.h>
#include <linux/smp.h>
#include <linux/resource.h>
#include <asm/smp_plat.h>
#include "common.h"
#include "pmsu.h"

static void __iomem *pmsu_mp_base;

#define PMSU_BASE_OFFSET    0x100
#define PMSU_REG_SIZE	    0x1000

#define PMSU_BOOT_ADDR_REDIRECT_OFFSET(cpu)	((cpu * 0x100) + 0x124)

static struct of_device_id of_pmsu_table[] = {
	{ .compatible = "marvell,armada-370-pmsu", },
	{ .compatible = "marvell,armada-370-xp-pmsu", },
	{ /* end of list */ },
};

#ifdef CONFIG_SMP
int armada_xp_boot_cpu(unsigned int cpu_id, void *boot_addr)
{
	int hw_cpu, ret;

	if (!pmsu_mp_base) {
		pr_warn("Can't boot CPU. PMSU is uninitialized\n");
		return -ENODEV;
	}

	hw_cpu = cpu_logical_map(cpu_id);

	writel(virt_to_phys(boot_addr), pmsu_mp_base +
			PMSU_BOOT_ADDR_REDIRECT_OFFSET(hw_cpu));

	ret = mvebu_cpu_reset_deassert(hw_cpu);
	if (ret) {
		pr_warn("unable to boot CPU: %d\n", ret);
		return ret;
	}

	return 0;
}
#endif

static int __init armada_370_xp_pmsu_init(void)
{
	struct device_node *np;
	struct resource res;
	int ret = 0;

	np = of_find_matching_node(NULL, of_pmsu_table);
	if (!np)
		return 0;

	pr_info("Initializing Power Management Service Unit\n");

	if (of_address_to_resource(np, 0, &res)) {
		pr_err("unable to get resource\n");
		ret = -ENOENT;
		goto out;
	}

	if (of_device_is_compatible(np, "marvell,armada-370-xp-pmsu")) {
		pr_warn(FW_WARN "deprecated pmsu binding\n");
		res.start = res.start - PMSU_BASE_OFFSET;
		res.end = res.start + PMSU_REG_SIZE - 1;
	}

	if (!request_mem_region(res.start, resource_size(&res),
				np->full_name)) {
		pr_err("unable to request region\n");
		ret = -EBUSY;
		goto out;
	}

	pmsu_mp_base = ioremap(res.start, resource_size(&res));
	if (!pmsu_mp_base) {
		pr_err("unable to map registers\n");
		release_mem_region(res.start, resource_size(&res));
		ret = -ENOMEM;
		goto out;
	}

 out:
	of_node_put(np);
	return ret;
}

early_initcall(armada_370_xp_pmsu_init);