drivers/amba/tegra-ahb.c

Source file repositories/reference/linux-study-clean/drivers/amba/tegra-ahb.c

File Facts

System
Linux kernel
Corpus path
drivers/amba/tegra-ahb.c
Extension
.c
Size
7632 bytes
Lines
290
Domain
Driver Families
Bucket
drivers/amba
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 tegra_ahb {
	void __iomem	*regs;
	struct device	*dev;
	u32		ctx[];
};

static inline u32 gizmo_readl(struct tegra_ahb *ahb, u32 offset)
{
	return readl(ahb->regs + offset);
}

static inline void gizmo_writel(struct tegra_ahb *ahb, u32 value, u32 offset)
{
	writel(value, ahb->regs + offset);
}

#ifdef CONFIG_TEGRA_IOMMU_SMMU
int tegra_ahb_enable_smmu(struct device_node *dn)
{
	struct device *dev;
	u32 val;
	struct tegra_ahb *ahb;

	dev = driver_find_device_by_of_node(&tegra_ahb_driver.driver, dn);
	if (!dev)
		return -EPROBE_DEFER;
	ahb = dev_get_drvdata(dev);
	put_device(dev);
	val = gizmo_readl(ahb, AHB_ARBITRATION_XBAR_CTRL);
	val |= AHB_ARBITRATION_XBAR_CTRL_SMMU_INIT_DONE;
	gizmo_writel(ahb, val, AHB_ARBITRATION_XBAR_CTRL);
	return 0;
}
EXPORT_SYMBOL(tegra_ahb_enable_smmu);
#endif

static int __maybe_unused tegra_ahb_suspend(struct device *dev)
{
	int i;
	struct tegra_ahb *ahb = dev_get_drvdata(dev);

	for (i = 0; i < ARRAY_SIZE(tegra_ahb_gizmo); i++)
		ahb->ctx[i] = gizmo_readl(ahb, tegra_ahb_gizmo[i]);
	return 0;
}

static int __maybe_unused tegra_ahb_resume(struct device *dev)
{
	int i;
	struct tegra_ahb *ahb = dev_get_drvdata(dev);

	for (i = 0; i < ARRAY_SIZE(tegra_ahb_gizmo); i++)
		gizmo_writel(ahb, ahb->ctx[i], tegra_ahb_gizmo[i]);
	return 0;
}

static UNIVERSAL_DEV_PM_OPS(tegra_ahb_pm,
			    tegra_ahb_suspend,
			    tegra_ahb_resume, NULL);

static void tegra_ahb_gizmo_init(struct tegra_ahb *ahb)
{
	u32 val;

	val = gizmo_readl(ahb, AHB_GIZMO_AHB_MEM);
	val |= ENB_FAST_REARBITRATE | IMMEDIATE | DONT_SPLIT_AHB_WR;
	gizmo_writel(ahb, val, AHB_GIZMO_AHB_MEM);

	val = gizmo_readl(ahb, AHB_GIZMO_USB);
	val |= IMMEDIATE;
	gizmo_writel(ahb, val, AHB_GIZMO_USB);

	val = gizmo_readl(ahb, AHB_GIZMO_USB2);
	val |= IMMEDIATE;
	gizmo_writel(ahb, val, AHB_GIZMO_USB2);

	val = gizmo_readl(ahb, AHB_GIZMO_USB3);
	val |= IMMEDIATE;
	gizmo_writel(ahb, val, AHB_GIZMO_USB3);

	val = gizmo_readl(ahb, AHB_ARBITRATION_PRIORITY_CTRL);
	val |= PRIORITY_SELECT_USB |
		PRIORITY_SELECT_USB2 |
		PRIORITY_SELECT_USB3 |
		AHB_PRIORITY_WEIGHT(7);
	gizmo_writel(ahb, val, AHB_ARBITRATION_PRIORITY_CTRL);

	val = gizmo_readl(ahb, AHB_MEM_PREFETCH_CFG1);
	val &= ~MST_ID(~0);
	val |= PREFETCH_ENB |

Annotation

Implementation Notes