drivers/power/reset/as3722-poweroff.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Power off driver for ams AS3722 device.
   4  *
   5  * Copyright (c) 2013, NVIDIA CORPORATION.  All rights reserved.
   6  *
   7  * Author: Laxman Dewangan <ldewangan@nvidia.com>
   8  */
   9
  10 #include <linux/mfd/as3722.h>
  11 #include <linux/module.h>
  12 #include <linux/of.h>
  13 #include <linux/platform_device.h>
  14 #include <linux/reboot.h>
  15 #include <linux/slab.h>
  16
  17 struct as3722_poweroff {
  18         struct device *dev;
  19         struct as3722 *as3722;
  20 };
  21
  22 static int as3722_pm_power_off(struct sys_off_data *data)
  23 {
  24         struct as3722_poweroff *as3722_pm_poweroff = data->cb_data;
  25         int ret;
  26
  27         ret = as3722_update_bits(as3722_pm_poweroff->as3722,
  28                 AS3722_RESET_CONTROL_REG, AS3722_POWER_OFF, AS3722_POWER_OFF);
  29         if (ret < 0)
  30                 dev_err(as3722_pm_poweroff->dev,
  31                         "RESET_CONTROL_REG update failed, %d\n", ret);
  32
  33         return NOTIFY_DONE;
  34 }
  35
  36 static int as3722_poweroff_probe(struct platform_device *pdev)
  37 {
  38         struct as3722_poweroff *as3722_poweroff;
  39         struct device_node *np = pdev->dev.parent->of_node;
  40
  41         if (!np)
  42                 return -EINVAL;
  43
  44         if (!of_property_read_bool(np, "ams,system-power-controller"))
  45                 return 0;
  46
  47         as3722_poweroff = devm_kzalloc(&pdev->dev, sizeof(*as3722_poweroff),
  48                                 GFP_KERNEL);
  49         if (!as3722_poweroff)
  50                 return -ENOMEM;
  51
  52         as3722_poweroff->as3722 = dev_get_drvdata(pdev->dev.parent);
  53         as3722_poweroff->dev = &pdev->dev;
  54
  55         return devm_register_sys_off_handler(as3722_poweroff->dev,
  56                                              SYS_OFF_MODE_POWER_OFF,
  57                                              SYS_OFF_PRIO_DEFAULT,
  58                                              as3722_pm_power_off,
  59                                              as3722_poweroff);
  60
  61         return 0;
  62 }
  63
  64 static struct platform_driver as3722_poweroff_driver = {
  65         .driver = {
  66                 .name = "as3722-power-off",
  67         },
  68         .probe = as3722_poweroff_probe,
  69 };
  70
  71 module_platform_driver(as3722_poweroff_driver);
  72
  73 MODULE_DESCRIPTION("Power off driver for ams AS3722 PMIC Device");
  74 MODULE_ALIAS("platform:as3722-power-off");
  75 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");