drivers/rtc/rtc-ds1511.c

Source file repositories/reference/linux-study-clean/drivers/rtc/rtc-ds1511.c

File Facts

System
Linux kernel
Corpus path
drivers/rtc/rtc-ds1511.c
Extension
.c
Size
9466 bytes
Lines
369
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 ds1511_data {
	struct rtc_device *rtc;
	void __iomem *ioaddr;		/* virtual base address */
	int irq;
	spinlock_t lock;
};

static DEFINE_SPINLOCK(ds1511_lock);

static __iomem char *ds1511_base;
static u32 reg_spacing = 1;

static void rtc_write(uint8_t val, uint32_t reg)
{
	writeb(val, ds1511_base + (reg * reg_spacing));
}

static uint8_t rtc_read(uint32_t reg)
{
	return readb(ds1511_base + (reg * reg_spacing));
}

static void rtc_disable_update(void)
{
	rtc_write((rtc_read(DS1511_CONTROL_B) & ~DS1511_TE), DS1511_CONTROL_B);
}

static void rtc_enable_update(void)
{
	rtc_write((rtc_read(DS1511_CONTROL_B) | DS1511_TE), DS1511_CONTROL_B);
}

static int ds1511_rtc_set_time(struct device *dev, struct rtc_time *rtc_tm)
{
	u8 mon, day, dow, hrs, min, sec, yrs, cen;
	unsigned long flags;

	yrs = rtc_tm->tm_year % 100;
	cen = 19 + rtc_tm->tm_year / 100;
	mon = rtc_tm->tm_mon + 1;   /* tm_mon starts at zero */
	day = rtc_tm->tm_mday;
	dow = rtc_tm->tm_wday & 0x7; /* automatic BCD */
	hrs = rtc_tm->tm_hour;
	min = rtc_tm->tm_min;
	sec = rtc_tm->tm_sec;

	/*
	 * each register is a different number of valid bits
	 */
	sec = bin2bcd(sec) & 0x7f;
	min = bin2bcd(min) & 0x7f;
	hrs = bin2bcd(hrs) & 0x3f;
	day = bin2bcd(day) & 0x3f;
	mon = bin2bcd(mon) & 0x1f;
	yrs = bin2bcd(yrs) & 0xff;
	cen = bin2bcd(cen) & 0xff;

	spin_lock_irqsave(&ds1511_lock, flags);
	rtc_disable_update();
	rtc_write(cen, DS1511_CENTURY);
	rtc_write(yrs, DS1511_YEAR);
	rtc_write((rtc_read(DS1511_MONTH) & 0xe0) | mon, DS1511_MONTH);
	rtc_write(day, DS1511_DOM);
	rtc_write(hrs, DS1511_HOUR);
	rtc_write(min, DS1511_MIN);
	rtc_write(sec, DS1511_SEC);
	rtc_write(dow, DS1511_DOW);
	rtc_enable_update();
	spin_unlock_irqrestore(&ds1511_lock, flags);

	return 0;
}

static int ds1511_rtc_read_time(struct device *dev, struct rtc_time *rtc_tm)
{
	unsigned int century;
	unsigned long flags;

	spin_lock_irqsave(&ds1511_lock, flags);
	rtc_disable_update();

	rtc_tm->tm_sec = rtc_read(DS1511_SEC) & 0x7f;
	rtc_tm->tm_min = rtc_read(DS1511_MIN) & 0x7f;
	rtc_tm->tm_hour = rtc_read(DS1511_HOUR) & 0x3f;
	rtc_tm->tm_mday = rtc_read(DS1511_DOM) & 0x3f;
	rtc_tm->tm_wday = rtc_read(DS1511_DOW) & 0x7;
	rtc_tm->tm_mon = rtc_read(DS1511_MONTH) & 0x1f;
	rtc_tm->tm_year = rtc_read(DS1511_YEAR) & 0x7f;
	century = rtc_read(DS1511_CENTURY);

Annotation

Implementation Notes