summaryrefslogtreecommitdiffstats
path: root/kernel/drivers/rtc/systohc.c
blob: b4a68ffcd06bb876231f2893de69f30a8fe854d9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
/*
 * 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/rtc.h>
#include <linux/time.h>

/**
 * rtc_set_ntp_time - Save NTP synchronized time to the RTC
 * @now: Current time of day
 *
 * Replacement for the NTP platform function update_persistent_clock64
 * that stores time for later retrieval by rtc_hctosys.
 *
 * Returns 0 on successful RTC update, -ENODEV if a RTC update is not
 * possible at all, and various other -errno for specific temporary failure
 * cases.
 *
 * If temporary failure is indicated the caller should try again 'soon'
 */
int rtc_set_ntp_time(struct timespec64 now)
{
	struct rtc_device *rtc;
	struct rtc_time tm;
	int err = -ENODEV;

	if (now.tv_nsec < (NSEC_PER_SEC >> 1))
		rtc_time64_to_tm(now.tv_sec, &tm);
	else
		rtc_time64_to_tm(now.tv_sec + 1, &tm);

	rtc = rtc_class_open(CONFIG_RTC_SYSTOHC_DEVICE);
	if (rtc) {
		/* rtc_hctosys exclusively uses UTC, so we call set_time here,
		 * not set_mmss. */
		if (rtc->ops &&
		    (rtc->ops->set_time ||
		     rtc->ops->set_mmss64 ||
		     rtc->ops->set_mmss))
			err = rtc_set_time(rtc, &tm);
		rtc_class_close(rtc);
	}

	return err;
}
eric.Error */ .highlight .gh { color: #333333 } /* Generic.Heading */ .highlight .gi { color: #000000; background-color: #ddffdd } /* Generic.Inserted */ .highlight .go { color: #888888 } /* Generic.Output */ .highlight .gp { color: #555555 } /* Generic.Prompt */ .highlight .gs { font-weight: bold } /* Generic.Strong */ .highlight .gu { color: #666666 } /* Generic.Subheading */ .highlight .gt { color: #aa0000 } /* Generic.Traceback */ .highlight .kc { color: #008800; font-weight: bold } /* Keyword.Constant */ .highlight .kd { color: #008800; font-weight: bold } /* Keyword.Declaration */ .highlight .kn { color: #008800; font-weight: bold } /* Keyword.Namespace */ .highlight .kp { color: #008800 } /* Keyword.Pseudo */ .highlight .kr { color: #008800; font-weight: bold } /* Keyword.Reserved */ .highlight .kt { color: #888888; font-weight: bold } /* Keyword.Type */ .highlight .m { color: #0000DD; font-weight: bold } /* Literal.Number */ .highlight .s { color: #dd2200; background-color: #fff0f0 } /* Literal.String */ .highlight .na { color: #336699 } /* Name.Attribute */ .highlight .nb { color: #003388 } /* Name.Builtin */ .highlight .nc { color: #bb0066; font-weight: bold } /* Name.Class */ .highlight .no { color: #003366; font-weight: bold } /* Name.Constant */ .highlight .nd { color: #555555 } /* Name.Decorator */ .highlight .ne { color: #bb0066; font-weight: bold } /* Name.Exception */ .highlight .nf { color: #0066bb; font-weight: bold } /* Name.Function */ .highlight .nl { color: #336699; font-style: italic } /* Name.Label */ .highlight .nn { color: #bb0066; font-weight: bold } /* Name.Namespace */ .highlight .py { color: #336699; font-weight: bold } /* Name.Property */ .highlight .nt { color: #bb0066; font-weight: bold } /* Name.Tag */ .highlight .nv { color: #336699 } /* Name.Variable */ .highlight .ow { color: #008800 } /* Operator.Word */ .highlight .w { color: #bbbbbb } /* Text.Whitespace */ .highlight .mb { color: #0000DD; font-weight: bold } /* Literal.Number.Bin */ .highlight .mf { color: #0000DD; font-weight: bold } /* Literal.Number.Float */ .highlight .mh { color: #0000DD; font-weight: bold } /* Literal.Number.Hex */ .highlight .mi { color: #0000DD; font-weight: bold } /* Literal.Number.Integer */ .highlight .mo { color: #0000DD; font-weight: bold } /* Literal.Number.Oct */ .highlight .sa { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Affix */ .highlight .sb { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Backtick */ .highlight .sc { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Char */ .highlight .dl { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Delimiter */ .highlight .sd { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Doc */ .highlight .s2 { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Double */ .highlight .se { color: #0044dd; background-color: #fff0f0 } /* Literal.String.Escape */ .highlight .sh { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Heredoc */ .highlight .si { color: #3333bb; background-color: #fff0f0 } /* Literal.String.Interpol */ .highlight .sx { color: #22bb22; background-color: #f0fff0 } /* Literal.String.Other */ .highlight .sr { color: #008800; background-color: #fff0ff } /* Literal.String.Regex */ .highlight .s1 { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Single */ .highlight .ss { color: #aa6600; background-color: #fff0f0 } /* Literal.String.Symbol */ .highlight .bp { color: #003388 } /* Name.Builtin.Pseudo */ .highlight .fm { color: #0066bb; font-weight: bold } /* Name.Function.Magic */ .highlight .vc { color: #336699 } /* Name.Variable.Class */ .highlight .vg { color: #dd7700 } /* Name.Variable.Global */ .highlight .vi { color: #3333bb } /* Name.Variable.Instance */ .highlight .vm { color: #336699 } /* Name.Variable.Magic */ .highlight .il { color: #0000DD; font-weight: bold } /* Literal.Number.Integer.Long */
/*
 * rtc-tps80031.c -- TI TPS80031/TPS80032 RTC driver
 *
 * RTC driver for TI TPS80031/TPS80032 Fully Integrated
 * Power Management with Power Path and Battery Charger
 *
 * Copyright (c) 2012, NVIDIA Corporation.
 *
 * Author: Laxman Dewangan <ldewangan@nvidia.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation version 2.
 *
 * This program is distributed "as is" WITHOUT ANY WARRANTY of any kind,
 * whether express or implied; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
 * 02111-1307, USA
 */

#include <linux/bcd.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mfd/tps80031.h>
#include <linux/platform_device.h>
#include <linux/pm.h>
#include <linux/rtc.h>
#include <linux/slab.h>

#define ENABLE_ALARM_INT			0x08
#define ALARM_INT_STATUS			0x40

/**
 * Setting bit to 1 in STOP_RTC will run the RTC and
 * setting this bit to 0 will freeze RTC.
 */
#define STOP_RTC				0x1

/* Power on reset Values of RTC registers */
#define TPS80031_RTC_POR_YEAR			0
#define TPS80031_RTC_POR_MONTH			1
#define TPS80031_RTC_POR_DAY			1

/* Numbers of registers for time and alarms */
#define TPS80031_RTC_TIME_NUM_REGS		7
#define TPS80031_RTC_ALARM_NUM_REGS		6

/**
 * PMU RTC have only 2 nibbles to store year information, so using an
 * offset of 100 to set the base year as 2000 for our driver.
 */
#define RTC_YEAR_OFFSET 100

struct tps80031_rtc {
	struct rtc_device	*rtc;
	int			irq;
};

static int tps80031_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
	u8 buff[TPS80031_RTC_TIME_NUM_REGS];
	int ret;

	ret = tps80031_reads(dev->parent, TPS80031_SLAVE_ID1,
			TPS80031_SECONDS_REG, TPS80031_RTC_TIME_NUM_REGS, buff);
	if (ret < 0) {
		dev_err(dev, "reading RTC_SECONDS_REG failed, err = %d\n", ret);
		return ret;
	}

	tm->tm_sec = bcd2bin(buff[0]);
	tm->tm_min = bcd2bin(buff[1]);
	tm->tm_hour = bcd2bin(buff[2]);
	tm->tm_mday = bcd2bin(buff[3]);
	tm->tm_mon = bcd2bin(buff[4]) - 1;
	tm->tm_year = bcd2bin(buff[5]) + RTC_YEAR_OFFSET;
	tm->tm_wday = bcd2bin(buff[6]);
	return 0;
}

static int tps80031_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
	u8 buff[7];
	int ret;

	buff[0] = bin2bcd(tm->tm_sec);
	buff[1] = bin2bcd(tm->tm_min);
	buff[2] = bin2bcd(tm->tm_hour);
	buff[3] = bin2bcd(tm->tm_mday);
	buff[4] = bin2bcd(tm->tm_mon + 1);
	buff[5] = bin2bcd(tm->tm_year % RTC_YEAR_OFFSET);
	buff[6] = bin2bcd(tm->tm_wday);

	/* Stop RTC while updating the RTC time registers */
	ret = tps80031_clr_bits(dev->parent, TPS80031_SLAVE_ID1,
				TPS80031_RTC_CTRL_REG, STOP_RTC);
	if (ret < 0) {
		dev_err(dev->parent, "Stop RTC failed, err = %d\n", ret);
		return ret;
	}

	ret = tps80031_writes(dev->parent, TPS80031_SLAVE_ID1,
			TPS80031_SECONDS_REG,
			TPS80031_RTC_TIME_NUM_REGS, buff);
	if (ret < 0) {
		dev_err(dev, "writing RTC_SECONDS_REG failed, err %d\n", ret);
		return ret;
	}

	ret = tps80031_set_bits(dev->parent, TPS80031_SLAVE_ID1,
				TPS80031_RTC_CTRL_REG, STOP_RTC);
	if (ret < 0)
		dev_err(dev->parent, "Start RTC failed, err = %d\n", ret);
	return ret;
}

static int tps80031_rtc_alarm_irq_enable(struct device *dev,
					 unsigned int enable)
{
	int ret;

	if (enable)
		ret = tps80031_set_bits(dev->parent, TPS80031_SLAVE_ID1,
				TPS80031_RTC_INTERRUPTS_REG, ENABLE_ALARM_INT);
	else
		ret = tps80031_clr_bits(dev->parent, TPS80031_SLAVE_ID1,
				TPS80031_RTC_INTERRUPTS_REG, ENABLE_ALARM_INT);
	if (ret < 0) {
		dev_err(dev, "Update on RTC_INT failed, err = %d\n", ret);
		return ret;
	}
	return 0;
}

static int tps80031_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
	u8 buff[TPS80031_RTC_ALARM_NUM_REGS];
	int ret;

	buff[0] = bin2bcd(alrm->time.tm_sec);
	buff[1] = bin2bcd(alrm->time.tm_min);
	buff[2] = bin2bcd(alrm->time.tm_hour);
	buff[3] = bin2bcd(alrm->time.tm_mday);
	buff[4] = bin2bcd(alrm->time.tm_mon + 1);
	buff[5] = bin2bcd(alrm->time.tm_year % RTC_YEAR_OFFSET);
	ret = tps80031_writes(dev->parent, TPS80031_SLAVE_ID1,
			TPS80031_ALARM_SECONDS_REG,
			TPS80031_RTC_ALARM_NUM_REGS, buff);
	if (ret < 0) {
		dev_err(dev, "Writing RTC_ALARM failed, err %d\n", ret);
		return ret;
	}
	return tps80031_rtc_alarm_irq_enable(dev, alrm->enabled);
}

static int tps80031_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
	u8 buff[6];
	int ret;

	ret = tps80031_reads(dev->parent, TPS80031_SLAVE_ID1,
			TPS80031_ALARM_SECONDS_REG,
			TPS80031_RTC_ALARM_NUM_REGS, buff);
	if (ret < 0) {
		dev_err(dev->parent,
			"reading RTC_ALARM failed, err = %d\n", ret);
		return ret;
	}

	alrm->time.tm_sec = bcd2bin(buff[0]);
	alrm->time.tm_min = bcd2bin(buff[1]);
	alrm->time.tm_hour = bcd2bin(buff[2]);
	alrm->time.tm_mday = bcd2bin(buff[3]);
	alrm->time.tm_mon = bcd2bin(buff[4]) - 1;
	alrm->time.tm_year = bcd2bin(buff[5]) + RTC_YEAR_OFFSET;
	return 0;
}

static int clear_alarm_int_status(struct device *dev, struct tps80031_rtc *rtc)
{
	int ret;
	u8 buf;

	/**
	 * As per datasheet, A dummy read of this  RTC_STATUS_REG register
	 * is necessary before each I2C read in order to update the status
	 * register value.
	 */
	ret = tps80031_read(dev->parent, TPS80031_SLAVE_ID1,
				TPS80031_RTC_STATUS_REG, &buf);
	if (ret < 0) {
		dev_err(dev, "reading RTC_STATUS failed. err = %d\n", ret);
		return ret;
	}

	/* clear Alarm status bits.*/
	ret = tps80031_set_bits(dev->parent, TPS80031_SLAVE_ID1,
			TPS80031_RTC_STATUS_REG, ALARM_INT_STATUS);
	if (ret < 0) {
		dev_err(dev, "clear Alarm INT failed, err = %d\n", ret);
		return ret;
	}
	return 0;
}

static irqreturn_t tps80031_rtc_irq(int irq, void *data)
{
	struct device *dev = data;
	struct tps80031_rtc *rtc = dev_get_drvdata(dev);
	int ret;

	ret = clear_alarm_int_status(dev, rtc);
	if (ret < 0)
		return ret;

	rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF);
	return IRQ_HANDLED;
}

static const struct rtc_class_ops tps80031_rtc_ops = {
	.read_time = tps80031_rtc_read_time,
	.set_time = tps80031_rtc_set_time,
	.set_alarm = tps80031_rtc_set_alarm,
	.read_alarm = tps80031_rtc_read_alarm,
	.alarm_irq_enable = tps80031_rtc_alarm_irq_enable,
};

static int tps80031_rtc_probe(struct platform_device *pdev)
{
	struct tps80031_rtc *rtc;
	struct rtc_time tm;
	int ret;

	rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
	if (!rtc)
		return -ENOMEM;

	rtc->irq = platform_get_irq(pdev, 0);
	platform_set_drvdata(pdev, rtc);

	/* Start RTC */
	ret = tps80031_set_bits(pdev->dev.parent, TPS80031_SLAVE_ID1,
			TPS80031_RTC_CTRL_REG, STOP_RTC);
	if (ret < 0) {
		dev_err(&pdev->dev, "failed to start RTC. err = %d\n", ret);
		return ret;
	}

	/* If RTC have POR values, set time 01:01:2000 */
	tps80031_rtc_read_time(&pdev->dev, &tm);
	if ((tm.tm_year == RTC_YEAR_OFFSET + TPS80031_RTC_POR_YEAR) &&
		(tm.tm_mon == (TPS80031_RTC_POR_MONTH - 1)) &&
		(tm.tm_mday == TPS80031_RTC_POR_DAY)) {
		tm.tm_year = 2000;
		tm.tm_mday = 1;
		tm.tm_mon = 1;
		ret = tps80031_rtc_set_time(&pdev->dev, &tm);
		if (ret < 0) {
			dev_err(&pdev->dev,
				"RTC set time failed, err = %d\n", ret);
			return ret;
		}
	}

	/* Clear alarm intretupt status if it is there */
	ret = clear_alarm_int_status(&pdev->dev, rtc);
	if (ret < 0) {
		dev_err(&pdev->dev, "Clear alarm int failed, err = %d\n", ret);
		return ret;
	}

	rtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
			       &tps80031_rtc_ops, THIS_MODULE);
	if (IS_ERR(rtc->rtc)) {
		ret = PTR_ERR(rtc->rtc);
		dev_err(&pdev->dev, "RTC registration failed, err %d\n", ret);
		return ret;
	}

	ret = devm_request_threaded_irq(&pdev->dev, rtc->irq, NULL,
			tps80031_rtc_irq,
			IRQF_ONESHOT | IRQF_EARLY_RESUME,
			dev_name(&pdev->dev), rtc);
	if (ret < 0) {
		dev_err(&pdev->dev, "request IRQ:%d failed, err = %d\n",
			 rtc->irq, ret);
		return ret;
	}
	device_set_wakeup_capable(&pdev->dev, 1);
	return 0;
}

#ifdef CONFIG_PM_SLEEP
static int tps80031_rtc_suspend(struct device *dev)
{
	struct tps80031_rtc *rtc = dev_get_drvdata(dev);

	if (device_may_wakeup(dev))
		enable_irq_wake(rtc->irq);
	return 0;
}

static int tps80031_rtc_resume(struct device *dev)
{
	struct tps80031_rtc *rtc = dev_get_drvdata(dev);

	if (device_may_wakeup(dev))
		disable_irq_wake(rtc->irq);
	return 0;
};
#endif

static SIMPLE_DEV_PM_OPS(tps80031_pm_ops, tps80031_rtc_suspend,
			tps80031_rtc_resume);

static struct platform_driver tps80031_rtc_driver = {
	.driver	= {
		.name	= "tps80031-rtc",
		.pm	= &tps80031_pm_ops,
	},
	.probe	= tps80031_rtc_probe,
};

module_platform_driver(tps80031_rtc_driver);

MODULE_ALIAS("platform:tps80031-rtc");
MODULE_DESCRIPTION("TI TPS80031/TPS80032 RTC driver");
MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
MODULE_LICENSE("GPL v2");