drivers/reset/reset-ath79.c

Source file repositories/reference/linux-study-clean/drivers/reset/reset-ath79.c

File Facts

System
Linux kernel
Corpus path
drivers/reset/reset-ath79.c
Extension
.c
Size
3052 bytes
Lines
129
Domain
Driver Families
Bucket
drivers/reset
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

struct ath79_reset {
	struct reset_controller_dev rcdev;
	void __iomem *base;
	spinlock_t lock;
};

#define FULL_CHIP_RESET 24

static int ath79_reset_update(struct reset_controller_dev *rcdev,
			unsigned long id, bool assert)
{
	struct ath79_reset *ath79_reset =
		container_of(rcdev, struct ath79_reset, rcdev);
	unsigned long flags;
	u32 val;

	spin_lock_irqsave(&ath79_reset->lock, flags);
	val = readl(ath79_reset->base);
	if (assert)
		val |= BIT(id);
	else
		val &= ~BIT(id);
	writel(val, ath79_reset->base);
	spin_unlock_irqrestore(&ath79_reset->lock, flags);

	return 0;
}

static int ath79_reset_assert(struct reset_controller_dev *rcdev,
			unsigned long id)
{
	return ath79_reset_update(rcdev, id, true);
}

static int ath79_reset_deassert(struct reset_controller_dev *rcdev,
				unsigned long id)
{
	return ath79_reset_update(rcdev, id, false);
}

static int ath79_reset_status(struct reset_controller_dev *rcdev,
			unsigned long id)
{
	struct ath79_reset *ath79_reset =
		container_of(rcdev, struct ath79_reset, rcdev);
	u32 val;

	val = readl(ath79_reset->base);

	return !!(val & BIT(id));
}

static const struct reset_control_ops ath79_reset_ops = {
	.assert = ath79_reset_assert,
	.deassert = ath79_reset_deassert,
	.status = ath79_reset_status,
};

static int ath79_reset_restart_handler(struct sys_off_data *data)
{
	struct ath79_reset *ath79_reset = data->cb_data;

	ath79_reset_assert(&ath79_reset->rcdev, FULL_CHIP_RESET);

	return NOTIFY_DONE;
}

static int ath79_reset_probe(struct platform_device *pdev)
{
	struct ath79_reset *ath79_reset;
	int err;

	ath79_reset = devm_kzalloc(&pdev->dev,
				sizeof(*ath79_reset), GFP_KERNEL);
	if (!ath79_reset)
		return -ENOMEM;

	ath79_reset->base = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(ath79_reset->base))
		return PTR_ERR(ath79_reset->base);

	spin_lock_init(&ath79_reset->lock);
	ath79_reset->rcdev.ops = &ath79_reset_ops;
	ath79_reset->rcdev.owner = THIS_MODULE;
	ath79_reset->rcdev.of_node = pdev->dev.of_node;
	ath79_reset->rcdev.of_reset_n_cells = 1;
	ath79_reset->rcdev.nr_resets = 32;

	err = devm_reset_controller_register(&pdev->dev, &ath79_reset->rcdev);
	if (err)

Annotation

Implementation Notes