drivers/rtc/rtc-ep93xx.c
Source file repositories/reference/linux-study-clean/drivers/rtc/rtc-ep93xx.c
File Facts
- System
- Linux kernel
- Corpus path
drivers/rtc/rtc-ep93xx.c- Extension
.c- Size
- 4204 bytes
- Lines
- 172
- 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.
- 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.
- Allocates kernel memory; connect allocation flags and lifetime to context constraints.
- Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.
Dependency Surface
linux/module.hlinux/mod_devicetable.hlinux/rtc.hlinux/platform_device.hlinux/io.hlinux/gfp.h
Detected Declarations
struct ep93xx_rtcfunction ep93xx_rtc_get_swcompfunction ep93xx_rtc_read_timefunction ep93xx_rtc_set_timefunction ep93xx_rtc_procfunction comp_preload_showfunction comp_delete_showfunction ep93xx_rtc_probe
Annotated Snippet
struct ep93xx_rtc {
void __iomem *mmio_base;
};
static int ep93xx_rtc_get_swcomp(struct device *dev, unsigned short *preload,
unsigned short *delete)
{
struct ep93xx_rtc *ep93xx_rtc = dev_get_drvdata(dev);
unsigned long comp;
comp = readl(ep93xx_rtc->mmio_base + EP93XX_RTC_SWCOMP);
if (preload)
*preload = (comp & EP93XX_RTC_SWCOMP_INT_MASK)
>> EP93XX_RTC_SWCOMP_INT_SHIFT;
if (delete)
*delete = (comp & EP93XX_RTC_SWCOMP_DEL_MASK)
>> EP93XX_RTC_SWCOMP_DEL_SHIFT;
return 0;
}
static int ep93xx_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
struct ep93xx_rtc *ep93xx_rtc = dev_get_drvdata(dev);
unsigned long time;
time = readl(ep93xx_rtc->mmio_base + EP93XX_RTC_DATA);
rtc_time64_to_tm(time, tm);
return 0;
}
static int ep93xx_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
struct ep93xx_rtc *ep93xx_rtc = dev_get_drvdata(dev);
unsigned long secs = rtc_tm_to_time64(tm);
writel(secs + 1, ep93xx_rtc->mmio_base + EP93XX_RTC_LOAD);
return 0;
}
static int ep93xx_rtc_proc(struct device *dev, struct seq_file *seq)
{
unsigned short preload, delete;
ep93xx_rtc_get_swcomp(dev, &preload, &delete);
seq_printf(seq, "preload\t\t: %d\n", preload);
seq_printf(seq, "delete\t\t: %d\n", delete);
return 0;
}
static const struct rtc_class_ops ep93xx_rtc_ops = {
.read_time = ep93xx_rtc_read_time,
.set_time = ep93xx_rtc_set_time,
.proc = ep93xx_rtc_proc,
};
static ssize_t comp_preload_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
unsigned short preload;
ep93xx_rtc_get_swcomp(dev->parent, &preload, NULL);
return sprintf(buf, "%d\n", preload);
}
static DEVICE_ATTR_RO(comp_preload);
static ssize_t comp_delete_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
unsigned short delete;
ep93xx_rtc_get_swcomp(dev->parent, NULL, &delete);
return sprintf(buf, "%d\n", delete);
}
static DEVICE_ATTR_RO(comp_delete);
static struct attribute *ep93xx_rtc_attrs[] = {
&dev_attr_comp_preload.attr,
&dev_attr_comp_delete.attr,
NULL
};
static const struct attribute_group ep93xx_rtc_sysfs_files = {
Annotation
- Immediate include surface: `linux/module.h`, `linux/mod_devicetable.h`, `linux/rtc.h`, `linux/platform_device.h`, `linux/io.h`, `linux/gfp.h`.
- Detected declarations: `struct ep93xx_rtc`, `function ep93xx_rtc_get_swcomp`, `function ep93xx_rtc_read_time`, `function ep93xx_rtc_set_time`, `function ep93xx_rtc_proc`, `function comp_preload_show`, `function comp_delete_show`, `function ep93xx_rtc_probe`.
- Atlas domain: Driver Families / drivers/rtc.
- Implementation status: source implementation candidate.
Implementation Notes
- This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
- Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
- Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.