drivers/hid/hid-wiimote-debug.c
Source file repositories/reference/linux-study-clean/drivers/hid/hid-wiimote-debug.c
File Facts
- System
- Linux kernel
- Corpus path
drivers/hid/hid-wiimote-debug.c- Extension
.c- Size
- 4686 bytes
- Lines
- 213
- Domain
- Driver Families
- Bucket
- drivers/hid
- Inferred role
- Driver Families: operation-table or driver-model contract
- Status
- pattern 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.
- Defines an operation table; this is where Linux turns generic core objects into subsystem-specific behavior.
- Touches user memory; correctness depends on fault-safe copying and privilege boundary handling.
- Uses kernel synchronization; read lock ordering, sleepability, and interrupt context assumptions before translating.
- 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/debugfs.hlinux/module.hlinux/seq_file.hlinux/spinlock.hlinux/uaccess.hhid-wiimote.h
Detected Declarations
struct wiimote_debugfunction wiidebug_eeprom_readfunction wiidebug_drm_showfunction wiidebug_drm_openfunction wiidebug_drm_writefunction wiidebug_initfunction wiidebug_deinit
Annotated Snippet
static const struct file_operations wiidebug_eeprom_fops = {
.owner = THIS_MODULE,
.open = simple_open,
.read = wiidebug_eeprom_read,
.llseek = generic_file_llseek,
};
static const char *wiidebug_drmmap[] = {
[WIIPROTO_REQ_NULL] = "NULL",
[WIIPROTO_REQ_DRM_K] = "K",
[WIIPROTO_REQ_DRM_KA] = "KA",
[WIIPROTO_REQ_DRM_KE] = "KE",
[WIIPROTO_REQ_DRM_KAI] = "KAI",
[WIIPROTO_REQ_DRM_KEE] = "KEE",
[WIIPROTO_REQ_DRM_KAE] = "KAE",
[WIIPROTO_REQ_DRM_KIE] = "KIE",
[WIIPROTO_REQ_DRM_KAIE] = "KAIE",
[WIIPROTO_REQ_DRM_E] = "E",
[WIIPROTO_REQ_DRM_SKAI1] = "SKAI1",
[WIIPROTO_REQ_DRM_SKAI2] = "SKAI2",
[WIIPROTO_REQ_MAX] = NULL
};
static int wiidebug_drm_show(struct seq_file *f, void *p)
{
struct wiimote_debug *dbg = f->private;
const char *str = NULL;
unsigned long flags;
__u8 drm;
spin_lock_irqsave(&dbg->wdata->state.lock, flags);
drm = dbg->wdata->state.drm;
spin_unlock_irqrestore(&dbg->wdata->state.lock, flags);
if (drm < WIIPROTO_REQ_MAX)
str = wiidebug_drmmap[drm];
if (!str)
str = "unknown";
seq_printf(f, "%s\n", str);
return 0;
}
static int wiidebug_drm_open(struct inode *i, struct file *f)
{
return single_open(f, wiidebug_drm_show, i->i_private);
}
static ssize_t wiidebug_drm_write(struct file *f, const char __user *u,
size_t s, loff_t *off)
{
struct seq_file *sf = f->private_data;
struct wiimote_debug *dbg = sf->private;
unsigned long flags;
char buf[16];
ssize_t len;
int i;
if (s == 0)
return -EINVAL;
len = min((size_t) 15, s);
if (copy_from_user(buf, u, len))
return -EFAULT;
buf[len] = 0;
for (i = 0; i < WIIPROTO_REQ_MAX; ++i) {
if (!wiidebug_drmmap[i])
continue;
if (!strcasecmp(buf, wiidebug_drmmap[i]))
break;
}
if (i == WIIPROTO_REQ_MAX)
i = simple_strtoul(buf, NULL, 16);
spin_lock_irqsave(&dbg->wdata->state.lock, flags);
dbg->wdata->state.flags &= ~WIIPROTO_FLAG_DRM_LOCKED;
wiiproto_req_drm(dbg->wdata, (__u8) i);
if (i != WIIPROTO_REQ_NULL)
dbg->wdata->state.flags |= WIIPROTO_FLAG_DRM_LOCKED;
spin_unlock_irqrestore(&dbg->wdata->state.lock, flags);
return len;
}
static const struct file_operations wiidebug_drm_fops = {
.owner = THIS_MODULE,
Annotation
- Immediate include surface: `linux/debugfs.h`, `linux/module.h`, `linux/seq_file.h`, `linux/spinlock.h`, `linux/uaccess.h`, `hid-wiimote.h`.
- Detected declarations: `struct wiimote_debug`, `function wiidebug_eeprom_read`, `function wiidebug_drm_show`, `function wiidebug_drm_open`, `function wiidebug_drm_write`, `function wiidebug_init`, `function wiidebug_deinit`.
- Atlas domain: Driver Families / drivers/hid.
- Implementation status: pattern implementation candidate.
- This snippet crosses the user/kernel memory boundary; validate fault handling and access checks before translating the pattern.
- Synchronization appears in or near this file; preserve lock ordering, sleepability, and interrupt-context constraints.
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.