drivers/media/platform/samsung/s5p-mfc/s5p_mfc_pm.c

Source file repositories/reference/linux-study-clean/drivers/media/platform/samsung/s5p-mfc/s5p_mfc_pm.c

File Facts

System
Linux kernel
Corpus path
drivers/media/platform/samsung/s5p-mfc/s5p_mfc_pm.c
Extension
.c
Size
2242 bytes
Lines
106
Domain
Driver Families
Bucket
drivers/media
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 (IS_ERR(pm->clocks[i])) {
			/* additional clocks are optional */
			if (i && PTR_ERR(pm->clocks[i]) == -ENOENT) {
				pm->clocks[i] = NULL;
				continue;
			}
			mfc_err("Failed to get clock: %s\n",
				pm->clk_names[i]);
			return PTR_ERR(pm->clocks[i]);
		}
	}

	if (dev->variant->use_clock_gating)
		pm->clock_gate = pm->clocks[0];

	pm_runtime_enable(pm->device);
	return 0;
}

void s5p_mfc_final_pm(struct s5p_mfc_dev *dev)
{
	pm_runtime_disable(dev->pm.device);
}

int s5p_mfc_clock_on(struct s5p_mfc_dev *dev)
{
	return clk_enable(dev->pm.clock_gate);
}

void s5p_mfc_clock_off(struct s5p_mfc_dev *dev)
{
	clk_disable(dev->pm.clock_gate);
}

int s5p_mfc_power_on(struct s5p_mfc_dev *dev)
{
	int i, ret = 0;

	ret = pm_runtime_resume_and_get(dev->pm.device);
	if (ret < 0)
		return ret;

	/* clock control */
	for (i = 0; i < dev->pm.num_clocks; i++) {
		ret = clk_prepare_enable(dev->pm.clocks[i]);
		if (ret < 0) {
			mfc_err("clock prepare failed for clock: %s\n",
				dev->pm.clk_names[i]);
			goto err;
		}
	}

	/* prepare for software clock gating */
	clk_disable(dev->pm.clock_gate);

	return 0;
err:
	while (--i >= 0)
		clk_disable_unprepare(dev->pm.clocks[i]);
	pm_runtime_put(dev->pm.device);
	return ret;
}

int s5p_mfc_power_off(struct s5p_mfc_dev *dev)
{
	int i;

	/* finish software clock gating */
	clk_enable(dev->pm.clock_gate);

	for (i = 0; i < dev->pm.num_clocks; i++)
		clk_disable_unprepare(dev->pm.clocks[i]);

	return pm_runtime_put_sync(dev->pm.device);
}

Annotation

Implementation Notes