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);
72