arch/arm/mach-vt8500/restart.c

   1 /* linux/arch/arm/mach-vt8500/restart.c
   2  *
   3  * Copyright (C) 2012 Tony Prisk <linux@prisktech.co.nz>
   4  *
   5  * This software is licensed under the terms of the GNU General Public
   6  * License version 2, as published by the Free Software Foundation, and
   7  * may be copied, distributed, and modified under those terms.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  */
  15 #include <asm/io.h>
  16 #include <linux/of.h>
  17 #include <linux/of_address.h>
  18
  19 #define LEGACY_PMC_BASE         0xD8130000
  20 #define WMT_PRIZM_PMSR_REG      0x60
  21
  22 static void __iomem *pmc_base;
  23
  24 void wmt_setup_restart(void)
  25 {
  26         struct device_node *np;
  27
  28         /*
  29          * Check if Power Mgmt Controller node is present in device tree. If no
  30          * device tree node, use the legacy PMSR value (valid for all current
  31          * SoCs).
  32          */
  33         np = of_find_compatible_node(NULL, NULL, "wmt,prizm-pmc");
  34         if (np) {
  35                 pmc_base = of_iomap(np, 0);
  36
  37                 if (!pmc_base)
  38                         pr_err("%s:of_iomap(pmc) failed\n", __func__);
  39
  40                 of_node_put(np);
  41         } else {
  42                 pmc_base = ioremap(LEGACY_PMC_BASE, 0x1000);
  43                 if (!pmc_base) {
  44                         pr_err("%s:ioremap(rstc) failed\n", __func__);
  45                         return;
  46                 }
  47         }
  48 }
  49
  50 void wmt_restart(char mode, const char *cmd)
  51 {
  52         if (pmc_base)
  53                 writel(1, pmc_base + WMT_PRIZM_PMSR_REG);
  54 }