drivers/power/reset/msm-poweroff.c

   1 /* Copyright (c) 2013, The Linux Foundation. All rights reserved.
   2  *
   3  * This program is free software; you can redistribute it and/or modify
   4  * it under the terms of the GNU General Public License version 2 and
   5  * only version 2 as published by the Free Software Foundation.
   6  *
   7  * This program is distributed in the hope that it will be useful,
   8  * but WITHOUT ANY WARRANTY; without even the implied warranty of
   9  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  10  * GNU General Public License for more details.
  11  *
  12  */
  13
  14 #include <linux/delay.h>
  15 #include <linux/err.h>
  16 #include <linux/init.h>
  17 #include <linux/kernel.h>
  18 #include <linux/io.h>
  19 #include <linux/of.h>
  20 #include <linux/platform_device.h>
  21 #include <linux/module.h>
  22 #include <linux/reboot.h>
  23 #include <linux/pm.h>
  24
  25 static void __iomem *msm_ps_hold;
  26 static int deassert_pshold(struct notifier_block *nb, unsigned long action,
  27                            void *data)
  28 {
  29         writel(0, msm_ps_hold);
  30         mdelay(10000);
  31
  32         return NOTIFY_DONE;
  33 }
  34
  35 static struct notifier_block restart_nb = {
  36         .notifier_call = deassert_pshold,
  37         .priority = 128,
  38 };
  39
  40 static void do_msm_poweroff(void)
  41 {
  42         deassert_pshold(&restart_nb, 0, NULL);
  43 }
  44
  45 static int msm_restart_probe(struct platform_device *pdev)
  46 {
  47         struct device *dev = &pdev->dev;
  48         struct resource *mem;
  49
  50         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  51         msm_ps_hold = devm_ioremap_resource(dev, mem);
  52         if (IS_ERR(msm_ps_hold))
  53                 return PTR_ERR(msm_ps_hold);
  54
  55         register_restart_handler(&restart_nb);
  56
  57         pm_power_off = do_msm_poweroff;
  58
  59         return 0;
  60 }
  61
  62 static const struct of_device_id of_msm_restart_match[] = {
  63         { .compatible = "qcom,pshold", },
  64         {},
  65 };
  66 MODULE_DEVICE_TABLE(of, of_msm_restart_match);
  67
  68 static struct platform_driver msm_restart_driver = {
  69         .probe = msm_restart_probe,
  70         .driver = {
  71                 .name = "msm-restart",
  72                 .of_match_table = of_match_ptr(of_msm_restart_match),
  73         },
  74 };
  75
  76 static int __init msm_restart_init(void)
  77 {
  78         return platform_driver_register(&msm_restart_driver);
  79 }
  80 device_initcall(msm_restart_init);