projects / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 2fa97feb LT |
1 | /* |
| 2 | * ACPI support for CMOS RTC Address Space access | |
| 3 | * | |
| 4 | * Copyright (C) 2013, Intel Corporation | |
| 5 | * Authors: Lan Tianyu <[email protected]> | |
| 6 | * | |
| 7 | * This program is free software; you can redistribute it and/or modify | |
| 8 | * it under the terms of the GNU General Public License version 2 as | |
| 9 | * published by the Free Software Foundation. | |
| 10 | */ | |
| 11 | ||
| 12 | #include <linux/acpi.h> | |
| 13 | #include <linux/device.h> | |
| 14 | #include <linux/err.h> | |
| 15 | #include <linux/kernel.h> | |
| 16 | #include <linux/module.h> | |
| 463a8630 | 17 | #include <linux/mc146818rtc.h> |
| 2fa97feb LT |
18 | |
| 19 | #include "internal.h" | |
| 20 | ||
| 2fa97feb LT |
21 | ACPI_MODULE_NAME("cmos rtc"); |
| 22 | ||
| 23 | static const struct acpi_device_id acpi_cmos_rtc_ids[] = { | |
| 24 | { "PNP0B00" }, | |
| 25 | { "PNP0B01" }, | |
| 26 | { "PNP0B02" }, | |
| 27 | {} | |
| 28 | }; | |
| 29 | ||
| 30 | static acpi_status | |
| 31 | acpi_cmos_rtc_space_handler(u32 function, acpi_physical_address address, | |
| 32 | u32 bits, u64 *value64, | |
| 33 | void *handler_context, void *region_context) | |
| 34 | { | |
| 35 | int i; | |
| 9389f46e | 36 | u8 *value = (u8 *)value64; |
| 2fa97feb LT |
37 | |
| 38 | if (address > 0xff || !value64) | |
| 39 | return AE_BAD_PARAMETER; | |
| 40 | ||
| 41 | if (function != ACPI_WRITE && function != ACPI_READ) | |
| 42 | return AE_BAD_PARAMETER; | |
| 43 | ||
| 44 | spin_lock_irq(&rtc_lock); | |
| 45 | ||
| 46 | for (i = 0; i < DIV_ROUND_UP(bits, 8); ++i, ++address, ++value) | |
| 47 | if (function == ACPI_READ) | |
| 48 | *value = CMOS_READ(address); | |
| 49 | else | |
| 50 | CMOS_WRITE(*value, address); | |
| 51 | ||
| 52 | spin_unlock_irq(&rtc_lock); | |
| 53 | ||
| 54 | return AE_OK; | |
| 55 | } | |
| 56 | ||
| 57 | static int acpi_install_cmos_rtc_space_handler(struct acpi_device *adev, | |
| 58 | const struct acpi_device_id *id) | |
| 59 | { | |
| 60 | acpi_status status; | |
| 61 | ||
| 62 | status = acpi_install_address_space_handler(adev->handle, | |
| 63 | ACPI_ADR_SPACE_CMOS, | |
| 64 | &acpi_cmos_rtc_space_handler, | |
| 65 | NULL, NULL); | |
| 66 | if (ACPI_FAILURE(status)) { | |
| 67 | pr_err(PREFIX "Error installing CMOS-RTC region handler\n"); | |
| 68 | return -ENODEV; | |
| 69 | } | |
| 70 | ||
| eec15edb | 71 | return 1; |
| 2fa97feb LT |
72 | } |
| 73 | ||
| 74 | static void acpi_remove_cmos_rtc_space_handler(struct acpi_device *adev) | |
| 75 | { | |
| 76 | if (ACPI_FAILURE(acpi_remove_address_space_handler(adev->handle, | |
| 77 | ACPI_ADR_SPACE_CMOS, &acpi_cmos_rtc_space_handler))) | |
| 78 | pr_err(PREFIX "Error removing CMOS-RTC region handler\n"); | |
| 79 | } | |
| 80 | ||
| 81 | static struct acpi_scan_handler cmos_rtc_handler = { | |
| 82 | .ids = acpi_cmos_rtc_ids, | |
| 83 | .attach = acpi_install_cmos_rtc_space_handler, | |
| 84 | .detach = acpi_remove_cmos_rtc_space_handler, | |
| 85 | }; | |
| 86 | ||
| 87 | void __init acpi_cmos_rtc_init(void) | |
| 88 | { | |
| 89 | acpi_scan_add_handler(&cmos_rtc_handler); | |
| 90 | } |