diff options
author | Lan Tianyu <tianyu.lan@intel.com> | 2013-06-05 02:27:50 (GMT) |
---|---|---|
committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2013-06-27 19:35:37 (GMT) |
commit | 2fa97feb4406c546b52e35b6b6c50cb8f63425d2 (patch) | |
tree | 48dbba1a1f9e6e7e9035030e605bdeb410df0d2f /drivers/acpi/acpi_cmos_rtc.c | |
parent | 358b4b35c8fa97a83c4d476cbd0830205504d798 (diff) | |
download | linux-fsl-qoriq-2fa97feb4406c546b52e35b6b6c50cb8f63425d2.tar.xz |
ACPI: Add CMOS RTC Operation Region handler support
On HP Folio 13-2000, the BIOS defines a CMOS RTC Operation Region and
the EC's _REG methord accesses that region. Thus an appropriate
address space handler must be registered for that region before the
EC driver is loaded.
Introduce a mechanism for adding CMOS RTC address space handlers.
Register an ACPI scan handler for CMOS RTC devices such that, when
a device of that kind is detected during an ACPI namespace scan, a
common CMOS RTC operation region address space handler will be
installed for it.
References: https://bugzilla.kernel.org/show_bug.cgi?id=54621
Reported-and-tested-by: Stefan Nagy <public@stefan-nagy.at>
Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Cc: 3.9+ <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/acpi/acpi_cmos_rtc.c')
-rw-r--r-- | drivers/acpi/acpi_cmos_rtc.c | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/drivers/acpi/acpi_cmos_rtc.c b/drivers/acpi/acpi_cmos_rtc.c new file mode 100644 index 0000000..84190ed --- /dev/null +++ b/drivers/acpi/acpi_cmos_rtc.c @@ -0,0 +1,92 @@ +/* + * ACPI support for CMOS RTC Address Space access + * + * Copyright (C) 2013, Intel Corporation + * Authors: Lan Tianyu <tianyu.lan@intel.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/acpi.h> +#include <linux/device.h> +#include <linux/err.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <asm-generic/rtc.h> + +#include "internal.h" + +#define PREFIX "ACPI: " + +ACPI_MODULE_NAME("cmos rtc"); + +static const struct acpi_device_id acpi_cmos_rtc_ids[] = { + { "PNP0B00" }, + { "PNP0B01" }, + { "PNP0B02" }, + {} +}; + +static acpi_status +acpi_cmos_rtc_space_handler(u32 function, acpi_physical_address address, + u32 bits, u64 *value64, + void *handler_context, void *region_context) +{ + int i; + u8 *value = (u8 *)&value64; + + if (address > 0xff || !value64) + return AE_BAD_PARAMETER; + + if (function != ACPI_WRITE && function != ACPI_READ) + return AE_BAD_PARAMETER; + + spin_lock_irq(&rtc_lock); + + for (i = 0; i < DIV_ROUND_UP(bits, 8); ++i, ++address, ++value) + if (function == ACPI_READ) + *value = CMOS_READ(address); + else + CMOS_WRITE(*value, address); + + spin_unlock_irq(&rtc_lock); + + return AE_OK; +} + +static int acpi_install_cmos_rtc_space_handler(struct acpi_device *adev, + const struct acpi_device_id *id) +{ + acpi_status status; + + status = acpi_install_address_space_handler(adev->handle, + ACPI_ADR_SPACE_CMOS, + &acpi_cmos_rtc_space_handler, + NULL, NULL); + if (ACPI_FAILURE(status)) { + pr_err(PREFIX "Error installing CMOS-RTC region handler\n"); + return -ENODEV; + } + + return 0; +} + +static void acpi_remove_cmos_rtc_space_handler(struct acpi_device *adev) +{ + if (ACPI_FAILURE(acpi_remove_address_space_handler(adev->handle, + ACPI_ADR_SPACE_CMOS, &acpi_cmos_rtc_space_handler))) + pr_err(PREFIX "Error removing CMOS-RTC region handler\n"); +} + +static struct acpi_scan_handler cmos_rtc_handler = { + .ids = acpi_cmos_rtc_ids, + .attach = acpi_install_cmos_rtc_space_handler, + .detach = acpi_remove_cmos_rtc_space_handler, +}; + +void __init acpi_cmos_rtc_init(void) +{ + acpi_scan_add_handler(&cmos_rtc_handler); +} |