drivers/macintosh/via-pmu-backlight.c

Source file repositories/reference/linux-study-clean/drivers/macintosh/via-pmu-backlight.c

File Facts

System
Linux kernel
Corpus path
drivers/macintosh/via-pmu-backlight.c
Extension
.c
Size
4515 bytes
Lines
188
Domain
Driver Families
Bucket
drivers/macintosh
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

if (diff < max) {
			max = diff;
			level = i;
		}
	}
	return level;
}

static int pmu_backlight_get_level_brightness(int level)
{
	int pmulevel;

	/* Get and convert the value */
	pmulevel = bl_curve[level] * FB_BACKLIGHT_MAX / MAX_PMU_LEVEL;
	if (pmulevel < 0)
		pmulevel = 0;
	else if (pmulevel > MAX_PMU_LEVEL)
		pmulevel = MAX_PMU_LEVEL;

	return pmulevel;
}

static int __pmu_backlight_update_status(struct backlight_device *bd)
{
	struct adb_request req;
	int level = backlight_get_brightness(bd);

	if (level > 0) {
		int pmulevel = pmu_backlight_get_level_brightness(level);

		pmu_request(&req, NULL, 2, PMU_BACKLIGHT_BRIGHT, pmulevel);
		pmu_wait_complete(&req);

		pmu_request(&req, NULL, 2, PMU_POWER_CTRL,
			PMU_POW_BACKLIGHT | PMU_POW_ON);
		pmu_wait_complete(&req);
	} else {
		pmu_request(&req, NULL, 2, PMU_POWER_CTRL,
			PMU_POW_BACKLIGHT | PMU_POW_OFF);
		pmu_wait_complete(&req);
	}

	return 0;
}

static int pmu_backlight_update_status(struct backlight_device *bd)
{
	unsigned long flags;
	int rc = 0;

	spin_lock_irqsave(&pmu_backlight_lock, flags);
	/* Don't update brightness when sleeping */
	if (!sleeping)
		rc = __pmu_backlight_update_status(bd);
	spin_unlock_irqrestore(&pmu_backlight_lock, flags);
	return rc;
}


static const struct backlight_ops pmu_backlight_data = {
	.update_status	= pmu_backlight_update_status,

};

#ifdef CONFIG_PM
void pmu_backlight_set_sleep(int sleep)
{
	unsigned long flags;

	spin_lock_irqsave(&pmu_backlight_lock, flags);
	sleeping = sleep;
	if (pmac_backlight && uses_pmu_bl) {
		if (sleep) {
			struct adb_request req;

			pmu_request(&req, NULL, 2, PMU_POWER_CTRL,
				    PMU_POW_BACKLIGHT | PMU_POW_OFF);
			pmu_wait_complete(&req);
		} else
			__pmu_backlight_update_status(pmac_backlight);
	}
	spin_unlock_irqrestore(&pmu_backlight_lock, flags);
}
#endif /* CONFIG_PM */

void __init pmu_backlight_init(void)
{
	struct backlight_properties props;
	struct backlight_device *bd;
	char name[10];

Annotation

Implementation Notes