ACPI: Add ACPI 5.0 Time and Alarm Device driver

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@suse.com>

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
 

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@suse.com)
+ *
+ * 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;
+}

drivers/acpi/bus.c

@@ -699,6 +699,9 @@ static int __init acpi_init(void)
 	pci_mmcfg_late_init();
 	acpi_scan_init();
 	acpi_ec_init();
+#ifdef CONFIG_X86
+	acpi_tad_init();
+#endif
 	acpi_debugfs_init();
 	acpi_sleep_proc_init();
 	acpi_wakeup_device_init();

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
   -------------------------------------------------------------------------- */

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);