xref: /linux/drivers/power/reset/brcmstb-reboot.c (revision 3a39d672e7f48b8d6b91a09afa4b55352773b4b5)
1 // SPDX-License-Identifier: GPL-2.0-only
2 // Copyright (C) 2013 Broadcom Corporation
3 
4 #include <linux/bitops.h>
5 #include <linux/device.h>
6 #include <linux/errno.h>
7 #include <linux/init.h>
8 #include <linux/io.h>
9 #include <linux/jiffies.h>
10 #include <linux/notifier.h>
11 #include <linux/of_address.h>
12 #include <linux/of_irq.h>
13 #include <linux/of_platform.h>
14 #include <linux/platform_device.h>
15 #include <linux/printk.h>
16 #include <linux/reboot.h>
17 #include <linux/regmap.h>
18 #include <linux/smp.h>
19 #include <linux/mfd/syscon.h>
20 
21 static struct regmap *regmap;
22 static u32 rst_src_en;
23 static u32 sw_mstr_rst;
24 
25 struct reset_reg_mask {
26 	u32 rst_src_en_mask;
27 	u32 sw_mstr_rst_mask;
28 };
29 
30 static const struct reset_reg_mask *reset_masks;
31 
brcmstb_restart_handler(struct sys_off_data * data)32 static int brcmstb_restart_handler(struct sys_off_data *data)
33 {
34 	int rc;
35 	u32 tmp;
36 
37 	rc = regmap_write(regmap, rst_src_en, reset_masks->rst_src_en_mask);
38 	if (rc) {
39 		pr_err("failed to write rst_src_en (%d)\n", rc);
40 		return NOTIFY_DONE;
41 	}
42 
43 	rc = regmap_read(regmap, rst_src_en, &tmp);
44 	if (rc) {
45 		pr_err("failed to read rst_src_en (%d)\n", rc);
46 		return NOTIFY_DONE;
47 	}
48 
49 	rc = regmap_write(regmap, sw_mstr_rst, reset_masks->sw_mstr_rst_mask);
50 	if (rc) {
51 		pr_err("failed to write sw_mstr_rst (%d)\n", rc);
52 		return NOTIFY_DONE;
53 	}
54 
55 	rc = regmap_read(regmap, sw_mstr_rst, &tmp);
56 	if (rc) {
57 		pr_err("failed to read sw_mstr_rst (%d)\n", rc);
58 		return NOTIFY_DONE;
59 	}
60 
61 	return NOTIFY_DONE;
62 }
63 
64 static const struct reset_reg_mask reset_bits_40nm = {
65 	.rst_src_en_mask = BIT(0),
66 	.sw_mstr_rst_mask = BIT(0),
67 };
68 
69 static const struct reset_reg_mask reset_bits_65nm = {
70 	.rst_src_en_mask = BIT(3),
71 	.sw_mstr_rst_mask = BIT(31),
72 };
73 
brcmstb_reboot_probe(struct platform_device * pdev)74 static int brcmstb_reboot_probe(struct platform_device *pdev)
75 {
76 	int rc;
77 	struct device_node *np = pdev->dev.of_node;
78 	unsigned int args[2];
79 
80 	reset_masks = device_get_match_data(&pdev->dev);
81 	if (!reset_masks) {
82 		pr_err("failed to get match data\n");
83 		return -EINVAL;
84 	}
85 
86 	regmap = syscon_regmap_lookup_by_phandle_args(np, "syscon", ARRAY_SIZE(args), args);
87 	if (IS_ERR(regmap)) {
88 		pr_err("failed to get syscon phandle\n");
89 		return -EINVAL;
90 	}
91 	rst_src_en = args[0];
92 	sw_mstr_rst = args[1];
93 
94 	rc = devm_register_sys_off_handler(&pdev->dev, SYS_OFF_MODE_RESTART,
95 					   128, brcmstb_restart_handler, NULL);
96 	if (rc)
97 		dev_err(&pdev->dev,
98 			"cannot register restart handler (err=%d)\n", rc);
99 
100 	return rc;
101 }
102 
103 static const struct of_device_id of_match[] = {
104 	{ .compatible = "brcm,brcmstb-reboot", .data = &reset_bits_40nm },
105 	{ .compatible = "brcm,bcm7038-reboot", .data = &reset_bits_65nm },
106 	{},
107 };
108 
109 static struct platform_driver brcmstb_reboot_driver = {
110 	.probe = brcmstb_reboot_probe,
111 	.driver = {
112 		.name = "brcmstb-reboot",
113 		.of_match_table = of_match,
114 	},
115 };
116 
brcmstb_reboot_init(void)117 static int __init brcmstb_reboot_init(void)
118 {
119 	return platform_driver_register(&brcmstb_reboot_driver);
120 }
121 subsys_initcall(brcmstb_reboot_init);
122