drivers/reset/reset-sunplus.c

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

File Facts

System
Linux kernel
Corpus path
drivers/reset/reset-sunplus.c
Extension
.c
Size
3655 bytes
Lines
208
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 sp_reset {
	struct reset_controller_dev rcdev;
	void __iomem *base;
};

static inline struct sp_reset *to_sp_reset(struct reset_controller_dev *rcdev)
{
	return container_of(rcdev, struct sp_reset, rcdev);
}

static int sp_reset_update(struct reset_controller_dev *rcdev,
			   unsigned long id, bool assert)
{
	struct sp_reset *reset = to_sp_reset(rcdev);
	int index = sp_resets[id] / BITS_PER_HWM_REG;
	int shift = sp_resets[id] % BITS_PER_HWM_REG;
	u32 val;

	val = (1 << (16 + shift)) | (assert << shift);
	writel(val, reset->base + (index * 4));

	return 0;
}

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

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

static int sp_reset_status(struct reset_controller_dev *rcdev,
			   unsigned long id)
{
	struct sp_reset *reset = to_sp_reset(rcdev);
	int index = sp_resets[id] / BITS_PER_HWM_REG;
	int shift = sp_resets[id] % BITS_PER_HWM_REG;
	u32 reg;

	reg = readl(reset->base + (index * 4));

	return !!(reg & BIT(shift));
}

static const struct reset_control_ops sp_reset_ops = {
	.assert   = sp_reset_assert,
	.deassert = sp_reset_deassert,
	.status   = sp_reset_status,
};

static int sp_restart(struct sys_off_data *data)
{
	struct sp_reset *reset = data->cb_data;

	sp_reset_assert(&reset->rcdev, 0);
	sp_reset_deassert(&reset->rcdev, 0);

	return NOTIFY_DONE;
}

static int sp_reset_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct sp_reset *reset;
	struct resource *res;
	int ret;

	reset = devm_kzalloc(dev, sizeof(*reset), GFP_KERNEL);
	if (!reset)
		return -ENOMEM;

	reset->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
	if (IS_ERR(reset->base))
		return PTR_ERR(reset->base);

	reset->rcdev.ops = &sp_reset_ops;
	reset->rcdev.owner = THIS_MODULE;
	reset->rcdev.of_node = dev->of_node;
	reset->rcdev.nr_resets = resource_size(res) / 4 * BITS_PER_HWM_REG;

	ret = devm_reset_controller_register(dev, &reset->rcdev);
	if (ret)
		return ret;

	return devm_register_sys_off_handler(&pdev->dev, SYS_OFF_MODE_RESTART,

Annotation

Implementation Notes