drivers/fpga/altera-fpga2sdram.c

Source file repositories/reference/linux-study-clean/drivers/fpga/altera-fpga2sdram.c

File Facts

System
Linux kernel
Corpus path
drivers/fpga/altera-fpga2sdram.c
Extension
.c
Size
4918 bytes
Lines
167
Domain
Driver Families
Bucket
drivers/fpga
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 alt_fpga2sdram_data {
	struct device *dev;
	struct regmap *sdrctl;
	int mask;
};

static int alt_fpga2sdram_enable_show(struct fpga_bridge *bridge)
{
	struct alt_fpga2sdram_data *priv = bridge->priv;
	int value;

	regmap_read(priv->sdrctl, ALT_SDR_CTL_FPGAPORTRST_OFST, &value);

	return (value & priv->mask) == priv->mask;
}

static inline int _alt_fpga2sdram_enable_set(struct alt_fpga2sdram_data *priv,
					     bool enable)
{
	return regmap_update_bits(priv->sdrctl, ALT_SDR_CTL_FPGAPORTRST_OFST,
				  priv->mask, enable ? priv->mask : 0);
}

static int alt_fpga2sdram_enable_set(struct fpga_bridge *bridge, bool enable)
{
	return _alt_fpga2sdram_enable_set(bridge->priv, enable);
}

static const struct fpga_bridge_ops altera_fpga2sdram_br_ops = {
	.enable_set = alt_fpga2sdram_enable_set,
	.enable_show = alt_fpga2sdram_enable_show,
};

static const struct of_device_id altera_fpga_of_match[] = {
	{ .compatible = "altr,socfpga-fpga2sdram-bridge" },
	{},
};

static int alt_fpga_bridge_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct alt_fpga2sdram_data *priv;
	struct fpga_bridge *br;
	u32 enable;
	struct regmap *sysmgr;
	int ret = 0;

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

	priv->dev = dev;

	priv->sdrctl = syscon_regmap_lookup_by_compatible("altr,sdr-ctl");
	if (IS_ERR(priv->sdrctl)) {
		dev_err(dev, "regmap for altr,sdr-ctl lookup failed.\n");
		return PTR_ERR(priv->sdrctl);
	}

	sysmgr = syscon_regmap_lookup_by_compatible("altr,sys-mgr");
	if (IS_ERR(sysmgr)) {
		dev_err(dev, "regmap for altr,sys-mgr lookup failed.\n");
		return PTR_ERR(sysmgr);
	}

	/* Get f2s bridge configuration saved in handoff register */
	regmap_read(sysmgr, SYSMGR_ISWGRP_HANDOFF3, &priv->mask);

	br = fpga_bridge_register(dev, F2S_BRIDGE_NAME,
				  &altera_fpga2sdram_br_ops, priv);
	if (IS_ERR(br))
		return PTR_ERR(br);

	platform_set_drvdata(pdev, br);

	dev_info(dev, "driver initialized with handoff %08x\n", priv->mask);

	if (!of_property_read_u32(dev->of_node, "bridge-enable", &enable)) {
		if (enable > 1) {
			dev_warn(dev, "invalid bridge-enable %u > 1\n", enable);
		} else {
			dev_info(dev, "%s bridge\n",
				 (enable ? "enabling" : "disabling"));
			ret = _alt_fpga2sdram_enable_set(priv, enable);
			if (ret) {
				fpga_bridge_unregister(br);
				return ret;
			}
		}
	}

Annotation

Implementation Notes