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         struct device *dev = &pdev->dev;
  39         struct resource *mem;
  40
  41         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  42         msm_ps_hold = devm_ioremap_resource(dev, mem);
  43         if (IS_ERR(msm_ps_hold))
  44                 return PTR_ERR(msm_ps_hold);
  45
  46         register_restart_handler(&restart_nb);
  47
  48         pm_power_off = do_msm_poweroff;
  49
  50         return 0;
  51 }
  52
  53 static const struct of_device_id of_msm_restart_match[] = {
  54         { .compatible = "qcom,pshold", },
  55         {},
  56 };
  57 MODULE_DEVICE_TABLE(of, of_msm_restart_match);
  58
  59 static struct platform_driver msm_restart_driver = {
  60         .probe = msm_restart_probe,
  61         .driver = {
  62                 .name = "msm-restart",
  63                 .of_match_table = of_match_ptr(of_msm_restart_match),
  64         },
  65 };
  66
  67 static int __init msm_restart_init(void)
  68 {
  69         return platform_driver_register(&msm_restart_driver);
  70 }
  71 device_initcall(msm_restart_init);