LXR linux/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/of_device.h>
  14#include <linux/platform_device.h>
  15#include <linux/slab.h>
  16
  17struct as3722_poweroff {
  18        struct device *dev;
  19        struct as3722 *as3722;
  20};
  21
  22static struct as3722_poweroff *as3722_pm_poweroff;
  23
  24static void as3722_pm_power_off(void)
  25{
  26        int ret;
  27
  28        if (!as3722_pm_poweroff) {
  29                pr_err("AS3722 poweroff is not initialised\n");
  30                return;
  31        }
  32
  33        ret = as3722_update_bits(as3722_pm_poweroff->as3722,
  34                AS3722_RESET_CONTROL_REG, AS3722_POWER_OFF, AS3722_POWER_OFF);
  35        if (ret < 0)
  36                dev_err(as3722_pm_poweroff->dev,
  37                        "RESET_CONTROL_REG update failed, %d\n", ret);
  38}
  39
  40static int as3722_poweroff_probe(struct platform_device *pdev)
  41{
  42        struct as3722_poweroff *as3722_poweroff;
  43        struct device_node *np = pdev->dev.parent->of_node;
  44
  45        if (!np)
  46                return -EINVAL;
  47
  48        if (!of_property_read_bool(np, "ams,system-power-controller"))
  49                return 0;
  50
  51        as3722_poweroff = devm_kzalloc(&pdev->dev, sizeof(*as3722_poweroff),
  52                                GFP_KERNEL);
  53        if (!as3722_poweroff)
  54                return -ENOMEM;
  55
  56        as3722_poweroff->as3722 = dev_get_drvdata(pdev->dev.parent);
  57        as3722_poweroff->dev = &pdev->dev;
  58        as3722_pm_poweroff = as3722_poweroff;
  59        if (!pm_power_off)
  60                pm_power_off = as3722_pm_power_off;
  61
  62        return 0;
  63}
  64
  65static int as3722_poweroff_remove(struct platform_device *pdev)
  66{
  67        if (pm_power_off == as3722_pm_power_off)
  68                pm_power_off = NULL;
  69        as3722_pm_poweroff = NULL;
  70
  71        return 0;
  72}
  73
  74static struct platform_driver as3722_poweroff_driver = {
  75        .driver = {
  76                .name = "as3722-power-off",
  77        },
  78        .probe = as3722_poweroff_probe,
  79        .remove = as3722_poweroff_remove,
  80};
  81
  82module_platform_driver(as3722_poweroff_driver);
  83
  84MODULE_DESCRIPTION("Power off driver for ams AS3722 PMIC Device");
  85MODULE_ALIAS("platform:as3722-power-off");
  86MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
  87MODULE_LICENSE("GPL v2");
  88