projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 8a577608 MF |
1 | /* |
| 2 | * Generic Syscon Poweroff Driver | |
| 3 | * | |
| 4 | * Copyright (c) 2015, National Instruments Corp. | |
| 5 | * Author: Moritz Fischer <moritz.fischer@ettus.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 | ||
| 18 | #include <linux/kallsyms.h> | |
| 19 | #include <linux/delay.h> | |
| 20 | #include <linux/io.h> | |
| 21 | #include <linux/notifier.h> | |
| 22 | #include <linux/mfd/syscon.h> | |
| 23 | #include <linux/of_address.h> | |
| 24 | #include <linux/of_device.h> | |
| 25 | #include <linux/platform_device.h> | |
| 26 | #include <linux/pm.h> | |
| 27 | #include <linux/regmap.h> | |
| 28 | ||
| 29 | static struct regmap *map; | |
| 30 | static u32 offset; | |
| 31 | static u32 mask; | |
| 32 | ||
| 33 | void syscon_poweroff(void) | |
| 34 | { | |
| 35 | /* Issue the poweroff */ | |
| 36 | regmap_write(map, offset, mask); | |
| 37 | ||
| 38 | mdelay(1000); | |
| 39 | ||
| 40 | pr_emerg("Unable to poweroff system\n"); | |
| 41 | } | |
| 42 | ||
| 43 | static int syscon_poweroff_probe(struct platform_device *pdev) | |
| 44 | { | |
| 45 | char symname[KSYM_NAME_LEN]; | |
| 46 | ||
| 47 | map = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, "regmap"); | |
| 48 | if (IS_ERR(map)) { | |
| 49 | dev_err(&pdev->dev, "unable to get syscon"); | |
| 50 | return PTR_ERR(map); | |
| 51 | } | |
| 52 | ||
| 53 | if (of_property_read_u32(pdev->dev.of_node, "offset", &offset)) { | |
| 54 | dev_err(&pdev->dev, "unable to read 'offset'"); | |
| 55 | return -EINVAL; | |
| 56 | } | |
| 57 | ||
| 58 | if (of_property_read_u32(pdev->dev.of_node, "mask", &mask)) { | |
| 59 | dev_err(&pdev->dev, "unable to read 'mask'"); | |
| 60 | return -EINVAL; | |
| 61 | } | |
| 62 | ||
| 63 | if (pm_power_off) { | |
| 64 | lookup_symbol_name((ulong)pm_power_off, symname); | |
| 65 | dev_err(&pdev->dev, | |
| 66 | "pm_power_off already claimed %p %s", | |
| 67 | pm_power_off, symname); | |
| 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); |