drivers/platform/mips/ls2k-reset.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  Copyright (C) 2021, Qing Zhang <zhangqing@loongson.cn>
   4  *  Loongson-2K1000 reset support
   5  */
   6
   7 #include <linux/of_address.h>
   8 #include <linux/pm.h>
   9 #include <asm/reboot.h>
  10
  11 #define PM1_STS         0x0c /* Power Management 1 Status Register */
  12 #define PM1_CNT         0x14 /* Power Management 1 Control Register */
  13 #define RST_CNT         0x30 /* Reset Control Register */
  14
  15 static void __iomem *base;
  16
  17 static void ls2k_restart(char *command)
  18 {
  19         writel(0x1, base + RST_CNT);
  20 }
  21
  22 static void ls2k_poweroff(void)
  23 {
  24         /* Clear */
  25         writel((readl(base + PM1_STS) & 0xffffffff), base + PM1_STS);
  26         /* Sleep Enable | Soft Off*/
  27         writel(GENMASK(12, 10) | BIT(13), base + PM1_CNT);
  28 }
  29
  30 static int ls2k_reset_init(void)
  31 {
  32         struct device_node *np;
  33
  34         np = of_find_compatible_node(NULL, NULL, "loongson,ls2k-pm");
  35         if (!np) {
  36                 pr_info("Failed to get PM node\n");
  37                 return -ENODEV;
  38         }
  39
  40         base = of_iomap(np, 0);
  41         of_node_put(np);
  42         if (!base) {
  43                 pr_info("Failed to map PM register base address\n");
  44                 return -ENOMEM;
  45         }
  46
  47         _machine_restart = ls2k_restart;
  48         pm_power_off = ls2k_poweroff;
  49
  50         return 0;
  51 }
  52
  53 arch_initcall(ls2k_reset_init);