drivers/rtc/rtc-rc5t583.c

Source file repositories/reference/linux-study-clean/drivers/rtc/rtc-rc5t583.c

File Facts

System
Linux kernel
Corpus path
drivers/rtc/rtc-rc5t583.c
Extension
.c
Size
8177 bytes
Lines
313
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 rc5t583_rtc {
	struct rtc_device	*rtc;
	/* To store the list of enabled interrupts, during system suspend */
	u32 irqen;
};

/* Total number of RTC registers needed to set time*/
#define NUM_TIME_REGS	(RC5T583_RTC_YEAR - RC5T583_RTC_SEC + 1)

/* Total number of RTC registers needed to set Y-Alarm*/
#define NUM_YAL_REGS	(RC5T583_RTC_AY_YEAR - RC5T583_RTC_AY_MIN + 1)

/* Set Y-Alarm interrupt */
#define SET_YAL BIT(5)

/* Get Y-Alarm interrupt status*/
#define GET_YAL_STATUS BIT(3)

static int rc5t583_rtc_alarm_irq_enable(struct device *dev, unsigned enabled)
{
	struct rc5t583 *rc5t583 = dev_get_drvdata(dev->parent);
	u8 val;

	/* Set Y-Alarm, based on 'enabled' */
	val = enabled ? SET_YAL : 0;

	return regmap_update_bits(rc5t583->regmap, RC5T583_RTC_CTL1, SET_YAL,
		val);
}

/*
 * Gets current rc5t583 RTC time and date parameters.
 *
 * The RTC's time/alarm representation is not what gmtime(3) requires
 * Linux to use:
 *
 *  - Months are 1..12 vs Linux 0-11
 *  - Years are 0..99 vs Linux 1900..N (we assume 21st century)
 */
static int rc5t583_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
	struct rc5t583 *rc5t583 = dev_get_drvdata(dev->parent);
	u8 rtc_data[NUM_TIME_REGS];
	int ret;

	ret = regmap_bulk_read(rc5t583->regmap, RC5T583_RTC_SEC, rtc_data,
		NUM_TIME_REGS);
	if (ret < 0) {
		dev_err(dev, "RTC read time failed with err:%d\n", ret);
		return ret;
	}

	tm->tm_sec = bcd2bin(rtc_data[0]);
	tm->tm_min = bcd2bin(rtc_data[1]);
	tm->tm_hour = bcd2bin(rtc_data[2]);
	tm->tm_wday = bcd2bin(rtc_data[3]);
	tm->tm_mday = bcd2bin(rtc_data[4]);
	tm->tm_mon = bcd2bin(rtc_data[5]) - 1;
	tm->tm_year = bcd2bin(rtc_data[6]) + 100;

	return ret;
}

static int rc5t583_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
	struct rc5t583 *rc5t583 = dev_get_drvdata(dev->parent);
	unsigned char rtc_data[NUM_TIME_REGS];
	int ret;

	rtc_data[0] = bin2bcd(tm->tm_sec);
	rtc_data[1] = bin2bcd(tm->tm_min);
	rtc_data[2] = bin2bcd(tm->tm_hour);
	rtc_data[3] = bin2bcd(tm->tm_wday);
	rtc_data[4] = bin2bcd(tm->tm_mday);
	rtc_data[5] = bin2bcd(tm->tm_mon + 1);
	rtc_data[6] = bin2bcd(tm->tm_year - 100);

	ret = regmap_bulk_write(rc5t583->regmap, RC5T583_RTC_SEC, rtc_data,
		NUM_TIME_REGS);
	if (ret < 0) {
		dev_err(dev, "RTC set time failed with error %d\n", ret);
		return ret;
	}

	return ret;
}

static int rc5t583_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
{
	struct rc5t583 *rc5t583 = dev_get_drvdata(dev->parent);

Annotation

Implementation Notes