drivers/power/reset/msm-poweroff.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /* Copyright (c) 2013, The Linux Foundation. All rights reserved.
   3  */
   4
   5 #include <linux/delay.h>
   6 #include <linux/err.h>
   7 #include <linux/init.h>
   8 #include <linux/kernel.h>
   9 #include <linux/io.h>
  10 #include <linux/of.h>
  11 #include <linux/platform_device.h>
  12 #include <linux/module.h>
  13 #include <linux/reboot.h>
  14 #include <linux/pm.h>
  15
  16 static void __iomem *msm_ps_hold;
  17 static int deassert_pshold(struct notifier_block *nb, unsigned long action,
  18                            void *data)
  19 {
  20         writel(0, msm_ps_hold);
  21         mdelay(10000);
  22
  23         return NOTIFY_DONE;
  24 }
  25
  26 static struct notifier_block restart_nb = {
  27         .notifier_call = deassert_pshold,
  28         .priority = 128,
  29 };
  30
  31 static void do_msm_poweroff(void)
  32 {
  33         deassert_pshold(&restart_nb, 0, NULL);
  34 }
  35
  36 static int msm_restart_probe(struct platform_device *pdev)
  37 {
  38         msm_ps_hold = devm_platform_ioremap_resource(pdev, 0);
  39         if (IS_ERR(msm_ps_hold))
  40                 return PTR_ERR(msm_ps_hold);
  41
  42         register_restart_handler(&restart_nb);
  43
  44         pm_power_off = do_msm_poweroff;
  45
  46         return 0;
  47 }
  48
  49 static const struct of_device_id of_msm_restart_match[] = {
  50         { .compatible = "qcom,pshold", },
  51         {},
  52 };
  53 MODULE_DEVICE_TABLE(of, of_msm_restart_match);
  54
  55 static struct platform_driver msm_restart_driver = {
  56         .probe = msm_restart_probe,
  57         .driver = {
  58                 .name = "msm-restart",
  59                 .of_match_table = of_match_ptr(of_msm_restart_match),
  60         },
  61 };
  62
  63 static int __init msm_restart_init(void)
  64 {
  65         return platform_driver_register(&msm_restart_driver);
  66 }
  67 device_initcall(msm_restart_init);