drivers/rtc/rtc-mt6397.c

Source file repositories/reference/linux-study-clean/drivers/rtc/rtc-mt6397.c

File Facts

System
Linux kernel
Corpus path
drivers/rtc/rtc-mt6397.c
Extension
.c
Size
9198 bytes
Lines
356
Domain
Driver Families
Bucket
drivers/rtc
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2014-2015 MediaTek Inc.
* Author: Tianping.Fang <tianping.fang@mediatek.com>
*/

#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/mfd/mt6397/core.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/rtc.h>
#include <linux/mfd/mt6397/rtc.h>
#include <linux/mod_devicetable.h>

static int mtk_rtc_write_trigger(struct mt6397_rtc *rtc)
{
	int ret;
	u32 data;

	ret = regmap_write(rtc->regmap, rtc->addr_base + rtc->data->wrtgr, 1);
	if (ret < 0)
		return ret;

	ret = regmap_read_poll_timeout(rtc->regmap,
					rtc->addr_base + RTC_BBPU, data,
					!(data & RTC_BBPU_CBUSY),
					MTK_RTC_POLL_DELAY_US,
					MTK_RTC_POLL_TIMEOUT);
	if (ret < 0)
		dev_err(rtc->rtc_dev->dev.parent,
			"failed to write WRTGR: %d\n", ret);

	return ret;
}

static irqreturn_t mtk_rtc_irq_handler_thread(int irq, void *data)
{
	struct mt6397_rtc *rtc = data;
	u32 irqsta, irqen;
	int ret;

	ret = regmap_read(rtc->regmap, rtc->addr_base + RTC_IRQ_STA, &irqsta);
	if ((ret >= 0) && (irqsta & RTC_IRQ_STA_AL)) {
		rtc_update_irq(rtc->rtc_dev, 1, RTC_IRQF | RTC_AF);
		irqen = irqsta & ~RTC_IRQ_EN_AL;
		mutex_lock(&rtc->lock);
		if (regmap_write(rtc->regmap, rtc->addr_base + RTC_IRQ_EN,
				 irqen) == 0)
			mtk_rtc_write_trigger(rtc);
		mutex_unlock(&rtc->lock);

		return IRQ_HANDLED;
	}

	return IRQ_NONE;
}

static int __mtk_rtc_read_time(struct mt6397_rtc *rtc,
			       struct rtc_time *tm, int *sec)
{
	int ret;
	u16 data[RTC_OFFSET_COUNT];

	mutex_lock(&rtc->lock);
	ret = regmap_bulk_read(rtc->regmap, rtc->addr_base + RTC_TC_SEC,
			       data, RTC_OFFSET_COUNT);
	if (ret < 0)
		goto exit;

	tm->tm_sec = data[RTC_OFFSET_SEC];
	tm->tm_min = data[RTC_OFFSET_MIN];
	tm->tm_hour = data[RTC_OFFSET_HOUR];
	tm->tm_mday = data[RTC_OFFSET_DOM];
	tm->tm_wday = data[RTC_OFFSET_DOW];
	tm->tm_mon = data[RTC_OFFSET_MTH] & RTC_TC_MTH_MASK;
	tm->tm_year = data[RTC_OFFSET_YEAR];

	ret = regmap_read(rtc->regmap, rtc->addr_base + RTC_TC_SEC, sec);
exit:
	mutex_unlock(&rtc->lock);
	return ret;
}

static int mtk_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
	struct mt6397_rtc *rtc = dev_get_drvdata(dev);

Annotation

Implementation Notes