drivers/reset/reset-zynq.c

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

File Facts

System
Linux kernel
Corpus path
drivers/reset/reset-zynq.c
Extension
.c
Size
3249 bytes
Lines
134
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 zynq_reset_data {
	struct regmap *slcr;
	struct reset_controller_dev rcdev;
	u32 offset;
};

#define to_zynq_reset_data(p)		\
	container_of((p), struct zynq_reset_data, rcdev)

static int zynq_reset_assert(struct reset_controller_dev *rcdev,
			     unsigned long id)
{
	struct zynq_reset_data *priv = to_zynq_reset_data(rcdev);

	int bank = id / BITS_PER_LONG;
	int offset = id % BITS_PER_LONG;

	pr_debug("%s: %s reset bank %u offset %u\n", KBUILD_MODNAME, __func__,
		 bank, offset);

	return regmap_update_bits(priv->slcr,
				  priv->offset + (bank * 4),
				  BIT(offset),
				  BIT(offset));
}

static int zynq_reset_deassert(struct reset_controller_dev *rcdev,
			       unsigned long id)
{
	struct zynq_reset_data *priv = to_zynq_reset_data(rcdev);

	int bank = id / BITS_PER_LONG;
	int offset = id % BITS_PER_LONG;

	pr_debug("%s: %s reset bank %u offset %u\n", KBUILD_MODNAME, __func__,
		 bank, offset);

	return regmap_update_bits(priv->slcr,
				  priv->offset + (bank * 4),
				  BIT(offset),
				  ~BIT(offset));
}

static int zynq_reset_status(struct reset_controller_dev *rcdev,
			     unsigned long id)
{
	struct zynq_reset_data *priv = to_zynq_reset_data(rcdev);

	int bank = id / BITS_PER_LONG;
	int offset = id % BITS_PER_LONG;
	int ret;
	u32 reg;

	pr_debug("%s: %s reset bank %u offset %u\n", KBUILD_MODNAME, __func__,
		 bank, offset);

	ret = regmap_read(priv->slcr, priv->offset + (bank * 4), &reg);
	if (ret)
		return ret;

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

static const struct reset_control_ops zynq_reset_ops = {
	.assert		= zynq_reset_assert,
	.deassert	= zynq_reset_deassert,
	.status		= zynq_reset_status,
};

static int zynq_reset_probe(struct platform_device *pdev)
{
	struct resource *res;
	struct zynq_reset_data *priv;

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

	priv->slcr = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
						     "syscon");
	if (IS_ERR(priv->slcr)) {
		dev_err(&pdev->dev, "unable to get zynq-slcr regmap");
		return PTR_ERR(priv->slcr);
	}

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!res) {
		dev_err(&pdev->dev, "missing IO resource\n");
		return -ENODEV;
	}

Annotation

Implementation Notes