drivers/mfd/wm8994-core.c

Source file repositories/reference/linux-study-clean/drivers/mfd/wm8994-core.c

File Facts

System
Linux kernel
Corpus path
drivers/mfd/wm8994-core.c
Extension
.c
Size
16243 bytes
Lines
675
Domain
Driver Families
Bucket
drivers/mfd
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 (ret < 0) {
			dev_err(dev, "Failed to read power status: %d\n", ret);
		} else if (ret & WM8958_MICD_ENA) {
			dev_dbg(dev, "CODEC still active, ignoring suspend\n");
			return 0;
		}
		break;
	default:
		break;
	}

	/* Disable LDO pulldowns while the device is suspended if we
	 * don't know that something will be driving them. */
	if (!wm8994->ldo_ena_always_driven)
		wm8994_set_bits(wm8994, WM8994_PULL_CONTROL_2,
				WM8994_LDO1ENA_PD | WM8994_LDO2ENA_PD,
				WM8994_LDO1ENA_PD | WM8994_LDO2ENA_PD);

	/* Explicitly put the device into reset in case regulators
	 * don't get disabled in order to ensure consistent restart.
	 */
	wm8994_reg_write(wm8994, WM8994_SOFTWARE_RESET,
			 wm8994_reg_read(wm8994, WM8994_SOFTWARE_RESET));

	regcache_mark_dirty(wm8994->regmap);

	/* Restore GPIO registers to prevent problems with mismatched
	 * pin configurations.
	 */
	ret = regcache_sync_region(wm8994->regmap, WM8994_GPIO_1,
				   WM8994_GPIO_11);
	if (ret != 0)
		dev_err(dev, "Failed to restore GPIO registers: %d\n", ret);

	/* In case one of the GPIOs is used as a wake input. */
	ret = regcache_sync_region(wm8994->regmap,
				   WM8994_INTERRUPT_STATUS_1_MASK,
				   WM8994_INTERRUPT_STATUS_1_MASK);
	if (ret != 0)
		dev_err(dev, "Failed to restore interrupt mask: %d\n", ret);

	regcache_cache_only(wm8994->regmap, true);
	wm8994->suspended = true;

	ret = regulator_bulk_disable(wm8994->num_supplies,
				     wm8994->supplies);
	if (ret != 0) {
		dev_err(dev, "Failed to disable supplies: %d\n", ret);
		return ret;
	}

	return 0;
}

static int wm8994_resume(struct device *dev)
{
	struct wm8994 *wm8994 = dev_get_drvdata(dev);
	int ret;

	/* We may have lied to the PM core about suspending */
	if (!wm8994->suspended)
		return 0;

	ret = regulator_bulk_enable(wm8994->num_supplies,
				    wm8994->supplies);
	if (ret != 0) {
		dev_err(dev, "Failed to enable supplies: %d\n", ret);
		return ret;
	}

	regcache_cache_only(wm8994->regmap, false);
	ret = regcache_sync(wm8994->regmap);
	if (ret != 0) {
		dev_err(dev, "Failed to restore register map: %d\n", ret);
		goto err_enable;
	}

	/* Disable LDO pulldowns while the device is active */
	wm8994_set_bits(wm8994, WM8994_PULL_CONTROL_2,
			WM8994_LDO1ENA_PD | WM8994_LDO2ENA_PD,
			0);

	wm8994->suspended = false;

	return 0;

err_enable:
	regulator_bulk_disable(wm8994->num_supplies, wm8994->supplies);

	return ret;

Annotation

Implementation Notes