Re: [RFC PATCH 04/14] ACPI: Add ACPI 5.0 Time and Alarm Device driver

From: Lan Tianyu
Date: Thu Jan 02 2014 - 03:09:28 EST


2013/12/19 Lee, Chun-Yi <joeyli.kernel@xxxxxxxxx>:
> This patch add the driver of Time and Alarm Device in ACPI 5.0.
> Currently it only implemented get/set time functions and grab
> the capabilities of device when driver initial.
>
> This driver also register rtc-acpitad platform device for RTC ACPITAD
> stub driver using.
>
> Signed-off-by: Lee, Chun-Yi <jlee@xxxxxxxx>
> ---
> drivers/acpi/Makefile | 3 +
> drivers/acpi/acpi_tad.c | 176 +++++++++++++++++++++++++++++++++++++++++++++++
> drivers/acpi/bus.c | 3 +
> drivers/acpi/internal.h | 5 ++
> include/linux/acpi.h | 31 ++++++++
> 5 files changed, 218 insertions(+), 0 deletions(-)
> create mode 100644 drivers/acpi/acpi_tad.c
>
> diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
> index 0331f91..d250b15 100644
> --- a/drivers/acpi/Makefile
> +++ b/drivers/acpi/Makefile
> @@ -50,6 +50,9 @@ acpi-$(CONFIG_ACPI_NUMA) += numa.o
> ifdef CONFIG_ACPI_VIDEO
> acpi-y += video_detect.o
> endif
> +ifdef CONFIG_X86
> +acpi-y += acpi_tad.o
> +endif
>
> # These are (potentially) separate modules
>
> diff --git a/drivers/acpi/acpi_tad.c b/drivers/acpi/acpi_tad.c
> new file mode 100644
> index 0000000..c2200f3
> --- /dev/null
> +++ b/drivers/acpi/acpi_tad.c
> @@ -0,0 +1,176 @@
> +/* rtc.c - ACPI 5.0 Time and Alarm Driver
> + *
> + * Copyright (C) 2013 SUSE Linux Products GmbH. All rights reserved.
> + * Written by Lee, Chun-Yi (jlee@xxxxxxxx)
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public Licence
> + * as published by the Free Software Foundation; either version
> + * 2 of the Licence, or (at your option) any later version.
> + */
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <acpi/acpi_drivers.h>
> +
> +#include <asm/time.h>
> +
> +#define ACPI_TIME_ALARM_NAME "Time and Alarm"
> +ACPI_MODULE_NAME(ACPI_TIME_ALARM_NAME);
> +#define ACPI_TIME_ALARM_CLASS "time_alarm"
> +
> +static const struct acpi_device_id time_alarm_ids[] = {
> + {"ACPI000E", 0},
> + {"", 0},
> +};
> +MODULE_DEVICE_TABLE(acpi, time_alarm_ids);
> +
> +static struct platform_device rtc_acpitad_dev = {
> + .name = "rtc-acpitad",
> + .id = -1,
> +};
> +
> +static struct acpi_device *acpi_tad_dev;
> +static unsigned long long cap;
> +
> +int acpi_read_time(struct acpi_time *output)
> +{
> + unsigned long flags;
> + struct acpi_buffer result = { ACPI_ALLOCATE_BUFFER, NULL };
> + union acpi_object *obj;
> + struct acpi_time *acpit;
> + acpi_status status;
> +
> + if (!acpi_tad_dev)
> + return -ENODEV;
> +
> + if (!(cap & TAD_CAP_GETSETTIME))
> + return -EINVAL;
> +
> + if (!output)
> + return -EINVAL;
> +
> + spin_lock_irqsave(&rtc_lock, flags);
> + status = acpi_evaluate_object(acpi_tad_dev->handle, "_GRT", NULL, &result);
> + spin_unlock_irqrestore(&rtc_lock, flags);
> + if (ACPI_FAILURE(status)) {
> + ACPI_EXCEPTION((AE_INFO, status, "Evaluating _GRT"));
> + return -ENODEV;
> + }
> +
> + obj = result.pointer;
> + if (!obj ||
> + obj->type != ACPI_TYPE_BUFFER ||
> + obj->buffer.length > sizeof(struct acpi_time) ||
> + obj->buffer.length < offsetof(struct acpi_time, pad2)) {
> + dev_err(&acpi_tad_dev->dev, ACPI_TIME_ALARM_NAME
> + " Invalid _GRT data\n");
> + return -EINVAL;
> + }
> +
> + acpit = (struct acpi_time *) obj->buffer.pointer;
> + if (acpit) {
> + output->year = acpit->year;
> + output->month = acpit->month;
> + output->day = acpit->day;
> + output->hour = acpit->hour;
> + output->minute = acpit->minute;
> + output->second = acpit->second;
> + output->milliseconds = acpit->milliseconds;
> + output->timezone = acpit->timezone;
> + output->daylight = acpit->daylight;
> + }
> +
> + return 0;
> +}
> +EXPORT_SYMBOL(acpi_read_time);
> +
> +int acpi_set_time(struct acpi_time *acpit)
> +{
> + unsigned long flags;
> + struct acpi_object_list input;
> + union acpi_object params[1];
> + unsigned long long output;
> + acpi_status status;
> +
> + if (!acpi_tad_dev)
> + return -ENODEV;
> +
> + if (!(cap & TAD_CAP_GETSETTIME))
> + return -EINVAL;
> +
> + if (!acpit)
> + return -EINVAL;
> +
> + input.count = 1;
> + input.pointer = params;
> + params[0].type = ACPI_TYPE_BUFFER;
> + params[0].buffer.length = sizeof(struct acpi_time);
> + params[0].buffer.pointer = (void *) acpit;
> +
> + spin_lock_irqsave(&rtc_lock, flags);
> + status = acpi_evaluate_integer(acpi_tad_dev->handle, "_SRT", &input, &output);
> + spin_unlock_irqrestore(&rtc_lock, flags);
> + if (ACPI_FAILURE(status)) {
> + ACPI_EXCEPTION((AE_INFO, status, "Evaluating _SRT"));
> + return -ENODEV;
> + }
> +
> + return 0;
> +}
> +EXPORT_SYMBOL(acpi_set_time);
> +
> +int acpi_tad_get_capability(unsigned long *output)
> +{
> + if (!acpi_tad_dev)
> + return -ENODEV;
> +
> + *output = cap;
> +
> + return 0;
> +}
> +EXPORT_SYMBOL(acpi_tad_get_capability);
> +
> +static int acpi_time_alarm_add(struct acpi_device *device)
> +{
> + acpi_status status;
> +
> + if (!device)
> + return -EINVAL;
> +
> + acpi_tad_dev = device;
> +
> + /* evaluate _GCP */
> + status = acpi_evaluate_integer(device->handle, "_GCP", NULL, &cap);
> + if (ACPI_FAILURE(status)) {
> + ACPI_EXCEPTION((AE_INFO, status, "Evaluating _GCP"));
> + return -ENODEV;
> + }
> +
> + if (!(cap & TAD_CAP_GETSETTIME))
> + pr_warn(FW_INFO "Get/Set real time features not available.\n");
> +
> + if (platform_device_register(&rtc_acpitad_dev) < 0)
> + pr_err("Unable to register rtc-acpitad device\n");
> +
> + return 0;
> +}
> +
> +static struct acpi_driver acpi_time_alarm_driver = {
> + .name = "time_and_alarm",
> + .class = ACPI_TIME_ALARM_CLASS,
> + .ids = time_alarm_ids,
> + .ops = {
> + .add = acpi_time_alarm_add,
> + },
> +};
> +
> +int __init acpi_tad_init(void)
> +{
> + int result = 0;
> +
> + result = acpi_bus_register_driver(&acpi_time_alarm_driver);
> + if (result < 0)
> + return -ENODEV;
> +
> + return result;
> +}
> diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
> index bba9b72..3f7a075 100644
> --- a/drivers/acpi/bus.c
> +++ b/drivers/acpi/bus.c
> @@ -689,6 +689,9 @@ static int __init acpi_init(void)
> pci_mmcfg_late_init();
> acpi_scan_init();
> acpi_ec_init();
> +#ifdef CONFIG_X86
> + acpi_tad_init();
> +#endif

Why calling acpi_tad_init() directly here rather than using module_initcall?
Is there dependency?


> acpi_debugfs_init();
> acpi_sleep_proc_init();
> acpi_wakeup_device_init();
> diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h
> index a29739c..9cfe589 100644
> --- a/drivers/acpi/internal.h
> +++ b/drivers/acpi/internal.h
> @@ -134,6 +134,11 @@ void acpi_ec_block_transactions(void);
> void acpi_ec_unblock_transactions(void);
> void acpi_ec_unblock_transactions_early(void);
>
> +/* --------------------------------------------------------------------------
> + Time and Alarm Device
> + -------------------------------------------------------------------------- */
> +int acpi_tad_init(void);
> +
> /*--------------------------------------------------------------------------
> Suspend/Resume
> -------------------------------------------------------------------------- */
> diff --git a/include/linux/acpi.h b/include/linux/acpi.h
> index d9099b1..c8dc104 100644
> --- a/include/linux/acpi.h
> +++ b/include/linux/acpi.h
> @@ -173,6 +173,37 @@ extern int ec_transaction(u8 command,
> u8 *rdata, unsigned rdata_len);
> extern acpi_handle ec_get_handle(void);
>
> +/*
> + * Time and Alarm device capability flags
> + */
> +#define TAD_CAP_ACWAKE (1<<0)
> +#define TAD_CAP_DCWAKE (1<<1)
> +#define TAD_CAP_GETSETTIME (1<<2)
> +#define TAD_CAP_ACCURACY (1<<3)
> +
> +#define ACPI_TIME_AFFECTED_BY_DAYLIGHT (1<<0)
> +#define ACPI_TIME_ADJUSTED_FOR_DAYLIGHT (1<<1)
> +#define ACPI_ISDST (ACPI_TIME_AFFECTED_BY_DAYLIGHT|ACPI_TIME_ADJUSTED_FOR_DAYLIGHT)
> +#define ACPI_UNSPECIFIED_TIMEZONE 2047
> +
> +struct acpi_time {
> + u16 year;
> + u8 month;
> + u8 day;
> + u8 hour;
> + u8 minute;
> + u8 second;
> + u8 pad1;
> + u16 milliseconds;
> + s16 timezone;
> + u8 daylight;
> + u8 pad2[3];
> +};
> +
> +extern int acpi_read_time(struct acpi_time *acpit);
> +extern int acpi_set_time(struct acpi_time *acpit);
> +extern int acpi_tad_get_capability(unsigned long *output);
> +
> #if defined(CONFIG_ACPI_WMI) || defined(CONFIG_ACPI_WMI_MODULE)
>
> typedef void (*wmi_notify_handler) (u32 value, void *context);
> --
> 1.6.4.2
>
> --
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--
Best regards
Tianyu Lan
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