drivers/rtc/rtc-palmas.c

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

File Facts

System
Linux kernel
Corpus path
drivers/rtc/rtc-palmas.c
Extension
.c
Size
9769 bytes
Lines
363
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 palmas_rtc {
	struct rtc_device	*rtc;
	struct device		*dev;
	unsigned int		irq;
};

/* Total number of RTC registers needed to set time*/
#define PALMAS_NUM_TIME_REGS	(PALMAS_YEARS_REG - PALMAS_SECONDS_REG + 1)

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

	/* Copy RTC counting registers to static registers or latches */
	ret = palmas_update_bits(palmas, PALMAS_RTC_BASE, PALMAS_RTC_CTRL_REG,
		PALMAS_RTC_CTRL_REG_GET_TIME, PALMAS_RTC_CTRL_REG_GET_TIME);
	if (ret < 0) {
		dev_err(dev, "RTC CTRL reg update failed, err: %d\n", ret);
		return ret;
	}

	ret = palmas_bulk_read(palmas, PALMAS_RTC_BASE, PALMAS_SECONDS_REG,
			rtc_data, PALMAS_NUM_TIME_REGS);
	if (ret < 0) {
		dev_err(dev, "RTC_SECONDS reg read failed, 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_mday = bcd2bin(rtc_data[3]);
	tm->tm_mon = bcd2bin(rtc_data[4]) - 1;
	tm->tm_year = bcd2bin(rtc_data[5]) + 100;

	return ret;
}

static int palmas_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
	unsigned char rtc_data[PALMAS_NUM_TIME_REGS];
	struct palmas *palmas = dev_get_drvdata(dev->parent);
	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_mday);
	rtc_data[4] = bin2bcd(tm->tm_mon + 1);
	rtc_data[5] = bin2bcd(tm->tm_year - 100);

	/* Stop RTC while updating the RTC time registers */
	ret = palmas_update_bits(palmas, PALMAS_RTC_BASE, PALMAS_RTC_CTRL_REG,
		PALMAS_RTC_CTRL_REG_STOP_RTC, 0);
	if (ret < 0) {
		dev_err(dev, "RTC stop failed, err = %d\n", ret);
		return ret;
	}

	ret = palmas_bulk_write(palmas, PALMAS_RTC_BASE, PALMAS_SECONDS_REG,
		rtc_data, PALMAS_NUM_TIME_REGS);
	if (ret < 0) {
		dev_err(dev, "RTC_SECONDS reg write failed, err = %d\n", ret);
		return ret;
	}

	/* Start back RTC */
	ret = palmas_update_bits(palmas, PALMAS_RTC_BASE, PALMAS_RTC_CTRL_REG,
		PALMAS_RTC_CTRL_REG_STOP_RTC, PALMAS_RTC_CTRL_REG_STOP_RTC);
	if (ret < 0)
		dev_err(dev, "RTC start failed, err = %d\n", ret);
	return ret;
}

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

	val = enabled ? PALMAS_RTC_INTERRUPTS_REG_IT_ALARM : 0;
	return palmas_write(palmas, PALMAS_RTC_BASE,
		PALMAS_RTC_INTERRUPTS_REG, val);
}

static int palmas_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
{
	unsigned char alarm_data[PALMAS_NUM_TIME_REGS];
	u32 int_val;

Annotation

Implementation Notes