1 /*
2  * Copyright (C) 2013 Broadcom Corporation
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public License as
6  * published by the Free Software Foundation version 2.
7  *
8  * This program is distributed "as is" WITHOUT ANY WARRANTY of any
9  * kind, whether express or implied; without even the implied warranty
10  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11  * GNU General Public License for more details.
12  */
13 
14 #include <linux/device.h>
15 #include <linux/errno.h>
16 #include <linux/init.h>
17 #include <linux/io.h>
18 #include <linux/jiffies.h>
19 #include <linux/of_address.h>
20 #include <linux/of_irq.h>
21 #include <linux/of_platform.h>
22 #include <linux/platform_device.h>
23 #include <linux/printk.h>
24 #include <linux/reboot.h>
25 #include <linux/regmap.h>
26 #include <linux/smp.h>
27 #include <linux/mfd/syscon.h>
28 
29 #include <asm/system_misc.h>
30 
31 #define RESET_SOURCE_ENABLE_REG 1
32 #define SW_MASTER_RESET_REG 2
33 
34 static struct regmap *regmap;
35 static u32 rst_src_en;
36 static u32 sw_mstr_rst;
37 
38 static void brcmstb_reboot(enum reboot_mode mode, const char *cmd)
39 {
40 	int rc;
41 	u32 tmp;
42 
43 	rc = regmap_write(regmap, rst_src_en, 1);
44 	if (rc) {
45 		pr_err("failed to write rst_src_en (%d)\n", rc);
46 		return;
47 	}
48 
49 	rc = regmap_read(regmap, rst_src_en, &tmp);
50 	if (rc) {
51 		pr_err("failed to read rst_src_en (%d)\n", rc);
52 		return;
53 	}
54 
55 	rc = regmap_write(regmap, sw_mstr_rst, 1);
56 	if (rc) {
57 		pr_err("failed to write sw_mstr_rst (%d)\n", rc);
58 		return;
59 	}
60 
61 	rc = regmap_read(regmap, sw_mstr_rst, &tmp);
62 	if (rc) {
63 		pr_err("failed to read sw_mstr_rst (%d)\n", rc);
64 		return;
65 	}
66 
67 	while (1)
68 		;
69 }
70 
71 static int brcmstb_reboot_probe(struct platform_device *pdev)
72 {
73 	int rc;
74 	struct device_node *np = pdev->dev.of_node;
75 
76 	regmap = syscon_regmap_lookup_by_phandle(np, "syscon");
77 	if (IS_ERR(regmap)) {
78 		pr_err("failed to get syscon phandle\n");
79 		return -EINVAL;
80 	}
81 
82 	rc = of_property_read_u32_index(np, "syscon", RESET_SOURCE_ENABLE_REG,
83 					&rst_src_en);
84 	if (rc) {
85 		pr_err("can't get rst_src_en offset (%d)\n", rc);
86 		return -EINVAL;
87 	}
88 
89 	rc = of_property_read_u32_index(np, "syscon", SW_MASTER_RESET_REG,
90 					&sw_mstr_rst);
91 	if (rc) {
92 		pr_err("can't get sw_mstr_rst offset (%d)\n", rc);
93 		return -EINVAL;
94 	}
95 
96 	arm_pm_restart = brcmstb_reboot;
97 
98 	return 0;
99 }
100 
101 static const struct of_device_id of_match[] = {
102 	{ .compatible = "brcm,brcmstb-reboot", },
103 	{},
104 };
105 
106 static struct platform_driver brcmstb_reboot_driver = {
107 	.probe = brcmstb_reboot_probe,
108 	.driver = {
109 		.name = "brcmstb-reboot",
110 		.owner = THIS_MODULE,
111 		.of_match_table = of_match,
112 	},
113 };
114 
115 static int __init brcmstb_reboot_init(void)
116 {
117 	return platform_driver_probe(&brcmstb_reboot_driver,
118 					brcmstb_reboot_probe);
119 }
120 subsys_initcall(brcmstb_reboot_init);
121