cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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as3722-poweroff.c (2068B)

      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");