projects / linux-block.git / blame
| Commit | Line | Data |
|---|---|---|
| c942fddf | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
| 09fb07bc FK |
2 | /* |
| 3 | * Generic Syscon Reboot Driver | |
| 4 | * | |
| 5 | * Copyright (c) 2013, Applied Micro Circuits Corporation | |
| 6 | * Author: Feng Kan <fkan@apm.com> | |
| 09fb07bc | 7 | */ |
| afaebbdb | 8 | #include <linux/delay.h> |
| 09fb07bc | 9 | #include <linux/io.h> |
| 09fb07bc FK |
10 | #include <linux/notifier.h> |
| 11 | #include <linux/mfd/syscon.h> | |
| afaebbdb FK |
12 | #include <linux/of_address.h> |
| 13 | #include <linux/of_device.h> | |
| 14 | #include <linux/platform_device.h> | |
| 09fb07bc | 15 | #include <linux/reboot.h> |
| afaebbdb | 16 | #include <linux/regmap.h> |
| 09fb07bc FK |
17 | |
| 18 | struct syscon_reboot_context { | |
| 19 | struct regmap *map; | |
| 20 | u32 offset; | |
| 077d9951 | 21 | u32 value; |
| 09fb07bc FK |
22 | u32 mask; |
| 23 | struct notifier_block restart_handler; | |
| 24 | }; | |
| 25 | ||
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26 | static int syscon_restart_handle(struct notifier_block *this, |
| 27 | unsigned long mode, void *cmd) | |
| 28 | { | |
| afaebbdb FK |
29 | struct syscon_reboot_context *ctx = |
| 30 | container_of(this, struct syscon_reboot_context, | |
| 31 | restart_handler); | |
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32 | |
| 33 | /* Issue the reboot */ | |
| 077d9951 | 34 | regmap_update_bits(ctx->map, ctx->offset, ctx->mask, ctx->value); |
| 09fb07bc | 35 | |
| afaebbdb | 36 | mdelay(1000); |
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37 | |
| 38 | pr_emerg("Unable to restart system\n"); | |
| 39 | return NOTIFY_DONE; | |
| 40 | } | |
| 41 | ||
| 42 | static int syscon_reboot_probe(struct platform_device *pdev) | |
| 43 | { | |
| 44 | struct syscon_reboot_context *ctx; | |
| 45 | struct device *dev = &pdev->dev; | |
| 077d9951 | 46 | int mask_err, value_err; |
| 09fb07bc FK |
47 | int err; |
| 48 | ||
| 49 | ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL); | |
| 50 | if (!ctx) | |
| 51 | return -ENOMEM; | |
| 52 | ||
| 53 | ctx->map = syscon_regmap_lookup_by_phandle(dev->of_node, "regmap"); | |
| c3d80522 SS |
54 | if (IS_ERR(ctx->map)) { |
| 55 | ctx->map = syscon_node_to_regmap(dev->parent->of_node); | |
| 56 | if (IS_ERR(ctx->map)) | |
| 57 | return PTR_ERR(ctx->map); | |
| 58 | } | |
| 09fb07bc FK |
59 | |
| 60 | if (of_property_read_u32(pdev->dev.of_node, "offset", &ctx->offset)) | |
| 61 | return -EINVAL; | |
| 62 | ||
| 077d9951 MS |
63 | value_err = of_property_read_u32(pdev->dev.of_node, "value", &ctx->value); |
| 64 | mask_err = of_property_read_u32(pdev->dev.of_node, "mask", &ctx->mask); | |
| 65 | if (value_err && mask_err) { | |
| 66 | dev_err(dev, "unable to read 'value' and 'mask'"); | |
| 09fb07bc | 67 | return -EINVAL; |
| 077d9951 MS |
68 | } |
| 69 | ||
| 70 | if (value_err) { | |
| 71 | /* support old binding */ | |
| 72 | ctx->value = ctx->mask; | |
| 73 | ctx->mask = 0xFFFFFFFF; | |
| 74 | } else if (mask_err) { | |
| 75 | /* support value without mask*/ | |
| 76 | ctx->mask = 0xFFFFFFFF; | |
| 77 | } | |
| 09fb07bc FK |
78 | |
| 79 | ctx->restart_handler.notifier_call = syscon_restart_handle; | |
| b81180b3 | 80 | ctx->restart_handler.priority = 192; |
| 09fb07bc FK |
81 | err = register_restart_handler(&ctx->restart_handler); |
| 82 | if (err) | |
| 83 | dev_err(dev, "can't register restart notifier (err=%d)\n", err); | |
| 84 | ||
| afaebbdb | 85 | return err; |
| 09fb07bc FK |
86 | } |
| 87 | ||
| 8fb08855 | 88 | static const struct of_device_id syscon_reboot_of_match[] = { |
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89 | { .compatible = "syscon-reboot" }, |
| 90 | {} | |
| 91 | }; | |
| 92 | ||
| 93 | static struct platform_driver syscon_reboot_driver = { | |
| 94 | .probe = syscon_reboot_probe, | |
| 95 | .driver = { | |
| 96 | .name = "syscon-reboot", | |
| 97 | .of_match_table = syscon_reboot_of_match, | |
| 98 | }, | |
| 99 | }; | |
| e35415e5 | 100 | builtin_platform_driver(syscon_reboot_driver); |