1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  CLPS711X CPU idle driver
4  *
5  *  Copyright (C) 2014 Alexander Shiyan <shc_work@mail.ru>
6  */
7 
8 #include <linux/cpuidle.h>
9 #include <linux/err.h>
10 #include <linux/io.h>
11 #include <linux/init.h>
12 #include <linux/platform_device.h>
13 
14 #define CLPS711X_CPUIDLE_NAME	"clps711x-cpuidle"
15 
16 static void __iomem *clps711x_halt;
17 
18 static int clps711x_cpuidle_halt(struct cpuidle_device *dev,
19 				 struct cpuidle_driver *drv, int index)
20 {
21 	writel(0xaa, clps711x_halt);
22 
23 	return index;
24 }
25 
26 static struct cpuidle_driver clps711x_idle_driver = {
27 	.name		= CLPS711X_CPUIDLE_NAME,
28 	.owner		= THIS_MODULE,
29 	.states[0]	= {
30 		.name		= "HALT",
31 		.desc		= "CLPS711X HALT",
32 		.enter		= clps711x_cpuidle_halt,
33 		.exit_latency	= 1,
34 	},
35 	.state_count	= 1,
36 };
37 
38 static int __init clps711x_cpuidle_probe(struct platform_device *pdev)
39 {
40 	struct resource *res;
41 
42 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
43 	clps711x_halt = devm_ioremap_resource(&pdev->dev, res);
44 	if (IS_ERR(clps711x_halt))
45 		return PTR_ERR(clps711x_halt);
46 
47 	return cpuidle_register(&clps711x_idle_driver, NULL);
48 }
49 
50 static struct platform_driver clps711x_cpuidle_driver = {
51 	.driver	= {
52 		.name	= CLPS711X_CPUIDLE_NAME,
53 	},
54 };
55 builtin_platform_driver_probe(clps711x_cpuidle_driver, clps711x_cpuidle_probe);
56