drivers/reset/amlogic/reset-meson-common.c

Source file repositories/reference/linux-study-clean/drivers/reset/amlogic/reset-meson-common.c

File Facts

System
Linux kernel
Corpus path
drivers/reset/amlogic/reset-meson-common.c
Extension
.c
Size
3822 bytes
Lines
143
Domain
Driver Families
Bucket
drivers/reset
Inferred role
Driver Families: exported/initcall integration point
Status
integration 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 meson_reset {
	const struct meson_reset_param *param;
	struct reset_controller_dev rcdev;
	struct regmap *map;
};

static void meson_reset_offset_and_bit(struct meson_reset *data,
				       unsigned long id,
				       unsigned int *offset,
				       unsigned int *bit)
{
	unsigned int stride = regmap_get_reg_stride(data->map);

	*offset = (id / (stride * BITS_PER_BYTE)) * stride;
	*bit = id % (stride * BITS_PER_BYTE);
}

static int meson_reset_reset(struct reset_controller_dev *rcdev,
			     unsigned long id)
{
	struct meson_reset *data =
		container_of(rcdev, struct meson_reset, rcdev);
	unsigned int offset, bit;

	meson_reset_offset_and_bit(data, id, &offset, &bit);
	offset += data->param->reset_offset;

	return regmap_write(data->map, offset, BIT(bit));
}

static int meson_reset_level(struct reset_controller_dev *rcdev,
			     unsigned long id, bool assert)
{
	struct meson_reset *data =
		container_of(rcdev, struct meson_reset, rcdev);
	unsigned int offset, bit;

	meson_reset_offset_and_bit(data, id, &offset, &bit);
	offset += data->param->level_offset;
	assert ^= data->param->level_low_reset;

	return regmap_update_bits(data->map, offset,
				  BIT(bit), assert ? BIT(bit) : 0);
}

static int meson_reset_status(struct reset_controller_dev *rcdev,
			      unsigned long id)
{
	struct meson_reset *data =
		container_of(rcdev, struct meson_reset, rcdev);
	unsigned int val, offset, bit;

	meson_reset_offset_and_bit(data, id, &offset, &bit);
	offset += data->param->level_offset;

	regmap_read(data->map, offset, &val);
	val = !!(BIT(bit) & val);

	return val ^ data->param->level_low_reset;
}

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

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

static int meson_reset_level_toggle(struct reset_controller_dev *rcdev,
				    unsigned long id)
{
	int ret;

	ret = meson_reset_assert(rcdev, id);
	if (ret)
		return ret;

	return meson_reset_deassert(rcdev, id);
}

const struct reset_control_ops meson_reset_ops = {
	.reset		= meson_reset_reset,
	.assert		= meson_reset_assert,
	.deassert	= meson_reset_deassert,
	.status		= meson_reset_status,

Annotation

Implementation Notes