drivers/nvmem/snvs_lpgpr.c

Source file repositories/reference/linux-study-clean/drivers/nvmem/snvs_lpgpr.c

File Facts

System
Linux kernel
Corpus path
drivers/nvmem/snvs_lpgpr.c
Extension
.c
Size
3825 bytes
Lines
158
Domain
Driver Families
Bucket
drivers/nvmem
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 snvs_lpgpr_cfg {
	int offset;
	int offset_hplr;
	int offset_lplr;
	int size;
};

struct snvs_lpgpr_priv {
	struct device_d			*dev;
	struct regmap			*regmap;
	struct nvmem_config		cfg;
	const struct snvs_lpgpr_cfg	*dcfg;
};

static const struct snvs_lpgpr_cfg snvs_lpgpr_cfg_imx6q = {
	.offset		= IMX6Q_SNVS_LPGPR,
	.offset_hplr	= IMX6Q_SNVS_HPLR,
	.offset_lplr	= IMX6Q_SNVS_LPLR,
	.size		= 4,
};

static const struct snvs_lpgpr_cfg snvs_lpgpr_cfg_imx7d = {
	.offset		= IMX7D_SNVS_LPGPR,
	.offset_hplr	= IMX7D_SNVS_HPLR,
	.offset_lplr	= IMX7D_SNVS_LPLR,
	.size		= 16,
};

static int snvs_lpgpr_write(void *context, unsigned int offset, void *val,
			    size_t bytes)
{
	struct snvs_lpgpr_priv *priv = context;
	const struct snvs_lpgpr_cfg *dcfg = priv->dcfg;
	unsigned int lock_reg;
	int ret;

	ret = regmap_read(priv->regmap, dcfg->offset_hplr, &lock_reg);
	if (ret < 0)
		return ret;

	if (lock_reg & IMX_GPR_SL)
		return -EPERM;

	ret = regmap_read(priv->regmap, dcfg->offset_lplr, &lock_reg);
	if (ret < 0)
		return ret;

	if (lock_reg & IMX_GPR_HL)
		return -EPERM;

	return regmap_bulk_write(priv->regmap, dcfg->offset + offset, val,
				bytes / 4);
}

static int snvs_lpgpr_read(void *context, unsigned int offset, void *val,
			   size_t bytes)
{
	struct snvs_lpgpr_priv *priv = context;
	const struct snvs_lpgpr_cfg *dcfg = priv->dcfg;

	return regmap_bulk_read(priv->regmap, dcfg->offset + offset,
			       val, bytes / 4);
}

static int snvs_lpgpr_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct device_node *node = dev->of_node;
	struct device_node *syscon_node;
	struct snvs_lpgpr_priv *priv;
	struct nvmem_config *cfg;
	struct nvmem_device *nvmem;
	const struct snvs_lpgpr_cfg *dcfg;

	if (!node)
		return -ENOENT;

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

	dcfg = of_device_get_match_data(dev);
	if (!dcfg)
		return -EINVAL;

	syscon_node = of_get_parent(node);
	if (!syscon_node)
		return -ENODEV;

	priv->regmap = syscon_node_to_regmap(syscon_node);

Annotation

Implementation Notes