diff options
Diffstat (limited to 'drivers/power/reset/syscon-reboot.c')
-rw-r--r-- | drivers/power/reset/syscon-reboot.c | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/drivers/power/reset/syscon-reboot.c b/drivers/power/reset/syscon-reboot.c new file mode 100644 index 000000000000..815b901822cf --- /dev/null +++ b/drivers/power/reset/syscon-reboot.c | |||
@@ -0,0 +1,91 @@ | |||
1 | /* | ||
2 | * Generic Syscon Reboot Driver | ||
3 | * | ||
4 | * Copyright (c) 2013, Applied Micro Circuits Corporation | ||
5 | * Author: Feng Kan <fkan@apm.com> | ||
6 | * | ||
7 | * This program is free software; you can redistribute it and/or | ||
8 | * modify it under the terms of the GNU General Public License as | ||
9 | * published by the Free Software Foundation; either version 2 of | ||
10 | * the License, or (at your option) any later version. | ||
11 | * | ||
12 | * This program is distributed in the hope that it will be useful, | ||
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
15 | * GNU General Public License for more details. | ||
16 | */ | ||
17 | #include <linux/delay.h> | ||
18 | #include <linux/io.h> | ||
19 | #include <linux/notifier.h> | ||
20 | #include <linux/mfd/syscon.h> | ||
21 | #include <linux/of_address.h> | ||
22 | #include <linux/of_device.h> | ||
23 | #include <linux/platform_device.h> | ||
24 | #include <linux/reboot.h> | ||
25 | #include <linux/regmap.h> | ||
26 | |||
27 | struct syscon_reboot_context { | ||
28 | struct regmap *map; | ||
29 | u32 offset; | ||
30 | u32 mask; | ||
31 | struct notifier_block restart_handler; | ||
32 | }; | ||
33 | |||
34 | static int syscon_restart_handle(struct notifier_block *this, | ||
35 | unsigned long mode, void *cmd) | ||
36 | { | ||
37 | struct syscon_reboot_context *ctx = | ||
38 | container_of(this, struct syscon_reboot_context, | ||
39 | restart_handler); | ||
40 | |||
41 | /* Issue the reboot */ | ||
42 | regmap_write(ctx->map, ctx->offset, ctx->mask); | ||
43 | |||
44 | mdelay(1000); | ||
45 | |||
46 | pr_emerg("Unable to restart system\n"); | ||
47 | return NOTIFY_DONE; | ||
48 | } | ||
49 | |||
50 | static int syscon_reboot_probe(struct platform_device *pdev) | ||
51 | { | ||
52 | struct syscon_reboot_context *ctx; | ||
53 | struct device *dev = &pdev->dev; | ||
54 | int err; | ||
55 | |||
56 | ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL); | ||
57 | if (!ctx) | ||
58 | return -ENOMEM; | ||
59 | |||
60 | ctx->map = syscon_regmap_lookup_by_phandle(dev->of_node, "regmap"); | ||
61 | if (IS_ERR(ctx->map)) | ||
62 | return PTR_ERR(ctx->map); | ||
63 | |||
64 | if (of_property_read_u32(pdev->dev.of_node, "offset", &ctx->offset)) | ||
65 | return -EINVAL; | ||
66 | |||
67 | if (of_property_read_u32(pdev->dev.of_node, "mask", &ctx->mask)) | ||
68 | return -EINVAL; | ||
69 | |||
70 | ctx->restart_handler.notifier_call = syscon_restart_handle; | ||
71 | ctx->restart_handler.priority = 128; | ||
72 | err = register_restart_handler(&ctx->restart_handler); | ||
73 | if (err) | ||
74 | dev_err(dev, "can't register restart notifier (err=%d)\n", err); | ||
75 | |||
76 | return err; | ||
77 | } | ||
78 | |||
79 | static struct of_device_id syscon_reboot_of_match[] = { | ||
80 | { .compatible = "syscon-reboot" }, | ||
81 | {} | ||
82 | }; | ||
83 | |||
84 | static struct platform_driver syscon_reboot_driver = { | ||
85 | .probe = syscon_reboot_probe, | ||
86 | .driver = { | ||
87 | .name = "syscon-reboot", | ||
88 | .of_match_table = syscon_reboot_of_match, | ||
89 | }, | ||
90 | }; | ||
91 | module_platform_driver(syscon_reboot_driver); | ||