projects / mirror_ubuntu-jammy-kernel.git / blame
| Commit | Line | Data |
|---|---|---|
| d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
| 2fa97feb LT |
2 | /* |
| 3 | * ACPI support for CMOS RTC Address Space access | |
| 4 | * | |
| 5 | * Copyright (C) 2013, Intel Corporation | |
| 6 | * Authors: Lan Tianyu <tianyu.lan@intel.com> | |
| 2fa97feb LT |
7 | */ |
| 8 | ||
| 9 | #include <linux/acpi.h> | |
| 10 | #include <linux/device.h> | |
| 11 | #include <linux/err.h> | |
| 12 | #include <linux/kernel.h> | |
| 13 | #include <linux/module.h> | |
| 463a8630 | 14 | #include <linux/mc146818rtc.h> |
| 2fa97feb LT |
15 | |
| 16 | #include "internal.h" | |
| 17 | ||
| 2fa97feb LT |
18 | ACPI_MODULE_NAME("cmos rtc"); |
| 19 | ||
| 20 | static const struct acpi_device_id acpi_cmos_rtc_ids[] = { | |
| 21 | { "PNP0B00" }, | |
| 22 | { "PNP0B01" }, | |
| 23 | { "PNP0B02" }, | |
| 24 | {} | |
| 25 | }; | |
| 26 | ||
| 27 | static acpi_status | |
| 28 | acpi_cmos_rtc_space_handler(u32 function, acpi_physical_address address, | |
| 29 | u32 bits, u64 *value64, | |
| 30 | void *handler_context, void *region_context) | |
| 31 | { | |
| 32 | int i; | |
| 9389f46e | 33 | u8 *value = (u8 *)value64; |
| 2fa97feb LT |
34 | |
| 35 | if (address > 0xff || !value64) | |
| 36 | return AE_BAD_PARAMETER; | |
| 37 | ||
| 38 | if (function != ACPI_WRITE && function != ACPI_READ) | |
| 39 | return AE_BAD_PARAMETER; | |
| 40 | ||
| 41 | spin_lock_irq(&rtc_lock); | |
| 42 | ||
| 43 | for (i = 0; i < DIV_ROUND_UP(bits, 8); ++i, ++address, ++value) | |
| 44 | if (function == ACPI_READ) | |
| 45 | *value = CMOS_READ(address); | |
| 46 | else | |
| 47 | CMOS_WRITE(*value, address); | |
| 48 | ||
| 49 | spin_unlock_irq(&rtc_lock); | |
| 50 | ||
| 51 | return AE_OK; | |
| 52 | } | |
| 53 | ||
| 54 | static int acpi_install_cmos_rtc_space_handler(struct acpi_device *adev, | |
| 55 | const struct acpi_device_id *id) | |
| 56 | { | |
| 57 | acpi_status status; | |
| 58 | ||
| 59 | status = acpi_install_address_space_handler(adev->handle, | |
| 60 | ACPI_ADR_SPACE_CMOS, | |
| 61 | &acpi_cmos_rtc_space_handler, | |
| 62 | NULL, NULL); | |
| 63 | if (ACPI_FAILURE(status)) { | |
| 64 | pr_err(PREFIX "Error installing CMOS-RTC region handler\n"); | |
| 65 | return -ENODEV; | |
| 66 | } | |
| 67 | ||
| eec15edb | 68 | return 1; |
| 2fa97feb LT |
69 | } |
| 70 | ||
| 71 | static void acpi_remove_cmos_rtc_space_handler(struct acpi_device *adev) | |
| 72 | { | |
| 73 | if (ACPI_FAILURE(acpi_remove_address_space_handler(adev->handle, | |
| 74 | ACPI_ADR_SPACE_CMOS, &acpi_cmos_rtc_space_handler))) | |
| 75 | pr_err(PREFIX "Error removing CMOS-RTC region handler\n"); | |
| 76 | } | |
| 77 | ||
| 78 | static struct acpi_scan_handler cmos_rtc_handler = { | |
| 79 | .ids = acpi_cmos_rtc_ids, | |
| 80 | .attach = acpi_install_cmos_rtc_space_handler, | |
| 81 | .detach = acpi_remove_cmos_rtc_space_handler, | |
| 82 | }; | |
| 83 | ||
| 84 | void __init acpi_cmos_rtc_init(void) | |
| 85 | { | |
| 86 | acpi_scan_add_handler(&cmos_rtc_handler); | |
| 87 | } |