projects / linux-block.git / blame
| Commit | Line | Data |
|---|---|---|
| c942fddf | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
| 8a577608 MF |
2 | /* |
| 3 | * Generic Syscon Poweroff Driver | |
| 4 | * | |
| 5 | * Copyright (c) 2015, National Instruments Corp. | |
| 6 | * Author: Moritz Fischer <moritz.fischer@ettus.com> | |
| 8a577608 MF |
7 | */ |
| 8 | ||
| 8a577608 MF |
9 | #include <linux/delay.h> |
| 10 | #include <linux/io.h> | |
| 11 | #include <linux/notifier.h> | |
| 12 | #include <linux/mfd/syscon.h> | |
| 13 | #include <linux/of_address.h> | |
| 14 | #include <linux/of_device.h> | |
| 15 | #include <linux/platform_device.h> | |
| 16 | #include <linux/pm.h> | |
| 17 | #include <linux/regmap.h> | |
| 18 | ||
| 19 | static struct regmap *map; | |
| 20 | static u32 offset; | |
| f2c199db | 21 | static u32 value; |
| 8a577608 MF |
22 | static u32 mask; |
| 23 | ||
| d04b674e | 24 | static void syscon_poweroff(void) |
| 8a577608 MF |
25 | { |
| 26 | /* Issue the poweroff */ | |
| f2c199db | 27 | regmap_update_bits(map, offset, mask, value); |
| 8a577608 MF |
28 | |
| 29 | mdelay(1000); | |
| 30 | ||
| 31 | pr_emerg("Unable to poweroff system\n"); | |
| 32 | } | |
| 33 | ||
| 34 | static int syscon_poweroff_probe(struct platform_device *pdev) | |
| 35 | { | |
| f2c199db | 36 | int mask_err, value_err; |
| 8a577608 MF |
37 | |
| 38 | map = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, "regmap"); | |
| 39 | if (IS_ERR(map)) { | |
| 40 | dev_err(&pdev->dev, "unable to get syscon"); | |
| 41 | return PTR_ERR(map); | |
| 42 | } | |
| 43 | ||
| 44 | if (of_property_read_u32(pdev->dev.of_node, "offset", &offset)) { | |
| 45 | dev_err(&pdev->dev, "unable to read 'offset'"); | |
| 46 | return -EINVAL; | |
| 47 | } | |
| 48 | ||
| f2c199db GS |
49 | value_err = of_property_read_u32(pdev->dev.of_node, "value", &value); |
| 50 | mask_err = of_property_read_u32(pdev->dev.of_node, "mask", &mask); | |
| 51 | if (value_err && mask_err) { | |
| 52 | dev_err(&pdev->dev, "unable to read 'value' and 'mask'"); | |
| 8a577608 MF |
53 | return -EINVAL; |
| 54 | } | |
| 55 | ||
| f2c199db GS |
56 | if (value_err) { |
| 57 | /* support old binding */ | |
| 58 | value = mask; | |
| 59 | mask = 0xFFFFFFFF; | |
| 60 | } else if (mask_err) { | |
| 61 | /* support value without mask*/ | |
| 62 | mask = 0xFFFFFFFF; | |
| 63 | } | |
| 64 | ||
| 8a577608 | 65 | if (pm_power_off) { |
| 36dbca14 HD |
66 | dev_err(&pdev->dev, "pm_power_off already claimed for %ps", |
| 67 | pm_power_off); | |
| 8a577608 MF |
68 | return -EBUSY; |
| 69 | } | |
| 70 | ||
| 71 | pm_power_off = syscon_poweroff; | |
| 72 | ||
| 73 | return 0; | |
| 74 | } | |
| 75 | ||
| 76 | static int syscon_poweroff_remove(struct platform_device *pdev) | |
| 77 | { | |
| 78 | if (pm_power_off == syscon_poweroff) | |
| 79 | pm_power_off = NULL; | |
| 80 | ||
| 81 | return 0; | |
| 82 | } | |
| 83 | ||
| 84 | static const struct of_device_id syscon_poweroff_of_match[] = { | |
| 85 | { .compatible = "syscon-poweroff" }, | |
| 86 | {} | |
| 87 | }; | |
| 88 | ||
| 89 | static struct platform_driver syscon_poweroff_driver = { | |
| 90 | .probe = syscon_poweroff_probe, | |
| 91 | .remove = syscon_poweroff_remove, | |
| 92 | .driver = { | |
| 93 | .name = "syscon-poweroff", | |
| 94 | .of_match_table = syscon_poweroff_of_match, | |
| 95 | }, | |
| 96 | }; | |
| 97 | ||
| 98 | static int __init syscon_poweroff_register(void) | |
| 99 | { | |
| 100 | return platform_driver_register(&syscon_poweroff_driver); | |
| 101 | } | |
| 102 | device_initcall(syscon_poweroff_register); |