arch/arm/mach-mvebu/pmsu.c

   1 /*
   2  * Power Management Service Unit(PMSU) support for Armada 370/XP platforms.
   3  *
   4  * Copyright (C) 2012 Marvell
   5  *
   6  * Yehuda Yitschak <yehuday@marvell.com>
   7  * Gregory Clement <gregory.clement@free-electrons.com>
   8  * Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
   9  *
  10  * This file is licensed under the terms of the GNU General Public
  11  * License version 2.  This program is licensed "as is" without any
  12  * warranty of any kind, whether express or implied.
  13  *
  14  * The Armada 370 and Armada XP SOCs have a power management service
  15  * unit which is responsible for powering down and waking up CPUs and
  16  * other SOC units
  17  */
  18
  19 #include <linux/kernel.h>
  20 #include <linux/init.h>
  21 #include <linux/of_address.h>
  22 #include <linux/io.h>
  23 #include <linux/smp.h>
  24 #include <asm/smp_plat.h>
  25
  26 static void __iomem *pmsu_mp_base;
  27 static void __iomem *pmsu_reset_base;
  28
  29 #define PMSU_BOOT_ADDR_REDIRECT_OFFSET(cpu)     ((cpu * 0x100) + 0x24)
  30 #define PMSU_RESET_CTL_OFFSET(cpu)              (cpu * 0x8)
  31
  32 static struct of_device_id of_pmsu_table[] = {
  33         {.compatible = "marvell,armada-370-xp-pmsu"},
  34         { /* end of list */ },
  35 };
  36
  37 #ifdef CONFIG_SMP
  38 int armada_xp_boot_cpu(unsigned int cpu_id, void *boot_addr)
  39 {
  40         int reg, hw_cpu;
  41
  42         if (!pmsu_mp_base || !pmsu_reset_base) {
  43                 pr_warn("Can't boot CPU. PMSU is uninitialized\n");
  44                 return 1;
  45         }
  46
  47         hw_cpu = cpu_logical_map(cpu_id);
  48
  49         writel(virt_to_phys(boot_addr), pmsu_mp_base +
  50                         PMSU_BOOT_ADDR_REDIRECT_OFFSET(hw_cpu));
  51
  52         /* Release CPU from reset by clearing reset bit*/
  53         reg = readl(pmsu_reset_base + PMSU_RESET_CTL_OFFSET(hw_cpu));
  54         reg &= (~0x1);
  55         writel(reg, pmsu_reset_base + PMSU_RESET_CTL_OFFSET(hw_cpu));
  56
  57         return 0;
  58 }
  59 #endif
  60
  61 int __init armada_370_xp_pmsu_init(void)
  62 {
  63         struct device_node *np;
  64
  65         np = of_find_matching_node(NULL, of_pmsu_table);
  66         if (np) {
  67                 pr_info("Initializing Power Management Service Unit\n");
  68                 pmsu_mp_base = of_iomap(np, 0);
  69                 pmsu_reset_base = of_iomap(np, 1);
  70                 of_node_put(np);
  71         }
  72
  73         return 0;
  74 }
  75
  76 early_initcall(armada_370_xp_pmsu_init);