LXR linux/arch/arm/mach-mvebu/system-controller.c

   1/*
   2 * System controller support for Armada 370 and XP platforms.
   3 *
   4 * Copyright (C) 2012 Marvell
   5 *
   6 * Lior Amsalem <alior@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 both have a range of
  15 * miscellaneous registers, that do not belong to a particular device,
  16 * but rather provide system-level features. This basic
  17 * system-controller driver provides a device tree binding for those
  18 * registers, and implements utility functions offering various
  19 * features related to those registers.
  20 *
  21 * For now, the feature set is limited to restarting the platform by a
  22 * soft-reset, but it might be extended in the future.
  23 */
  24
  25#include <linux/kernel.h>
  26#include <linux/init.h>
  27#include <linux/of_address.h>
  28#include <linux/io.h>
  29#include <linux/reboot.h>
  30
  31static void __iomem *system_controller_base;
  32
  33struct mvebu_system_controller {
  34        u32 rstoutn_mask_offset;
  35        u32 system_soft_reset_offset;
  36
  37        u32 rstoutn_mask_reset_out_en;
  38        u32 system_soft_reset;
  39};
  40static struct mvebu_system_controller *mvebu_sc;
  41
  42const struct mvebu_system_controller armada_370_xp_system_controller = {
  43        .rstoutn_mask_offset = 0x60,
  44        .system_soft_reset_offset = 0x64,
  45        .rstoutn_mask_reset_out_en = 0x1,
  46        .system_soft_reset = 0x1,
  47};
  48
  49const struct mvebu_system_controller orion_system_controller = {
  50        .rstoutn_mask_offset = 0x108,
  51        .system_soft_reset_offset = 0x10c,
  52        .rstoutn_mask_reset_out_en = 0x4,
  53        .system_soft_reset = 0x1,
  54};
  55
  56static struct of_device_id of_system_controller_table[] = {
  57        {
  58                .compatible = "marvell,orion-system-controller",
  59                .data = (void *) &orion_system_controller,
  60        }, {
  61                .compatible = "marvell,armada-370-xp-system-controller",
  62                .data = (void *) &armada_370_xp_system_controller,
  63        },
  64        { /* end of list */ },
  65};
  66
  67void mvebu_restart(enum reboot_mode mode, const char *cmd)
  68{
  69        if (!system_controller_base) {
  70                pr_err("Cannot restart, system-controller not available: check the device tree\n");
  71        } else {
  72                /*
  73                 * Enable soft reset to assert RSTOUTn.
  74                 */
  75                writel(mvebu_sc->rstoutn_mask_reset_out_en,
  76                        system_controller_base +
  77                        mvebu_sc->rstoutn_mask_offset);
  78                /*
  79                 * Assert soft reset.
  80                 */
  81                writel(mvebu_sc->system_soft_reset,
  82                        system_controller_base +
  83                        mvebu_sc->system_soft_reset_offset);
  84        }
  85
  86        while (1)
  87                ;
  88}
  89
  90static int __init mvebu_system_controller_init(void)
  91{
  92        struct device_node *np;
  93
  94        np = of_find_matching_node(NULL, of_system_controller_table);
  95        if (np) {
  96                const struct of_device_id *match =
  97                    of_match_node(of_system_controller_table, np);
  98                BUG_ON(!match);
  99                system_controller_base = of_iomap(np, 0);
 100                mvebu_sc = (struct mvebu_system_controller *)match->data;
 101                of_node_put(np);
 102        }
 103
 104        return 0;
 105}
 106
 107arch_initcall(mvebu_system_controller_init);
 108