drivers/rtc/rtc-nxp-bbnsm.c

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

File Facts

System
Linux kernel
Corpus path
drivers/rtc/rtc-nxp-bbnsm.c
Extension
.c
Size
5855 bytes
Lines
232
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

struct bbnsm_rtc {
	struct rtc_device *rtc;
	struct regmap *regmap;
	int irq;
	struct clk *clk;
};

static u32 bbnsm_read_counter(struct bbnsm_rtc *bbnsm)
{
	u32 rtc_msb, rtc_lsb;
	unsigned int timeout = 100;
	u32 time;
	u32 tmp = 0;

	do {
		time = tmp;
		/* read the msb */
		regmap_read(bbnsm->regmap, BBNSM_RTC_MS, &rtc_msb);
		/* read the lsb */
		regmap_read(bbnsm->regmap, BBNSM_RTC_LS, &rtc_lsb);
		/* convert to seconds */
		tmp = (rtc_msb << 17) | (rtc_lsb >> 15);
	} while (tmp != time && --timeout);

	return time;
}

static int bbnsm_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
	struct bbnsm_rtc *bbnsm = dev_get_drvdata(dev);
	unsigned long time;
	u32 val;

	regmap_read(bbnsm->regmap, BBNSM_CTRL, &val);
	if ((val & RTC_EN_MSK) != RTC_EN)
		return -EINVAL;

	time = bbnsm_read_counter(bbnsm);
	rtc_time64_to_tm(time, tm);

	return 0;
}

static int bbnsm_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
	struct bbnsm_rtc *bbnsm = dev_get_drvdata(dev);
	unsigned long time = rtc_tm_to_time64(tm);

	/* disable the RTC first */
	regmap_update_bits(bbnsm->regmap, BBNSM_CTRL, RTC_EN_MSK, 0);

	/* write the 32bit sec time to 47 bit timer counter, leaving 15 LSBs blank */
	regmap_write(bbnsm->regmap, BBNSM_RTC_LS, time << CNTR_TO_SECS_SH);
	regmap_write(bbnsm->regmap, BBNSM_RTC_MS, time >> (32 - CNTR_TO_SECS_SH));

	/* Enable the RTC again */
	regmap_update_bits(bbnsm->regmap, BBNSM_CTRL, RTC_EN_MSK, RTC_EN);

	return 0;
}

static int bbnsm_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
	struct bbnsm_rtc *bbnsm = dev_get_drvdata(dev);
	u32 bbnsm_events, bbnsm_ta;

	regmap_read(bbnsm->regmap, BBNSM_TA, &bbnsm_ta);
	rtc_time64_to_tm(bbnsm_ta, &alrm->time);

	regmap_read(bbnsm->regmap, BBNSM_EVENTS, &bbnsm_events);
	alrm->pending = (bbnsm_events & BBNSM_EVENT_TA) ? 1 : 0;

	return 0;
}

static int bbnsm_rtc_alarm_irq_enable(struct device *dev, unsigned int enable)
{
	struct bbnsm_rtc *bbnsm = dev_get_drvdata(dev);

	/* enable the alarm event */
	regmap_update_bits(bbnsm->regmap, BBNSM_CTRL, TA_EN_MSK, enable ? TA_EN : TA_DIS);
	/* enable the alarm interrupt */
	regmap_update_bits(bbnsm->regmap, BBNSM_INT_EN, TA_EN_MSK, enable ? TA_EN : TA_DIS);

	return 0;
}

static int bbnsm_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
	struct bbnsm_rtc *bbnsm = dev_get_drvdata(dev);

Annotation

Implementation Notes