drivers/dma/milbeaut-xdmac.c

Source file repositories/reference/linux-study-clean/drivers/dma/milbeaut-xdmac.c

File Facts

System
Linux kernel
Corpus path
drivers/dma/milbeaut-xdmac.c
Extension
.c
Size
10305 bytes
Lines
422
Domain
Driver Families
Bucket
drivers/dma
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 milbeaut_xdmac_desc {
	struct virt_dma_desc vd;
	size_t len;
	dma_addr_t src;
	dma_addr_t dst;
};

struct milbeaut_xdmac_chan {
	struct virt_dma_chan vc;
	struct milbeaut_xdmac_desc *md;
	void __iomem *reg_ch_base;
};

struct milbeaut_xdmac_device {
	struct dma_device ddev;
	void __iomem *reg_base;
	struct milbeaut_xdmac_chan channels[];
};

static struct milbeaut_xdmac_chan *
to_milbeaut_xdmac_chan(struct virt_dma_chan *vc)
{
	return container_of(vc, struct milbeaut_xdmac_chan, vc);
}

static struct milbeaut_xdmac_desc *
to_milbeaut_xdmac_desc(struct virt_dma_desc *vd)
{
	return container_of(vd, struct milbeaut_xdmac_desc, vd);
}

/* mc->vc.lock must be held by caller */
static struct milbeaut_xdmac_desc *
milbeaut_xdmac_next_desc(struct milbeaut_xdmac_chan *mc)
{
	struct virt_dma_desc *vd;

	vd = vchan_next_desc(&mc->vc);
	if (!vd) {
		mc->md = NULL;
		return NULL;
	}

	list_del(&vd->node);

	mc->md = to_milbeaut_xdmac_desc(vd);

	return mc->md;
}

/* mc->vc.lock must be held by caller */
static void milbeaut_chan_start(struct milbeaut_xdmac_chan *mc,
				struct milbeaut_xdmac_desc *md)
{
	u32 val;

	/* Setup the channel */
	val = md->len - 1;
	writel_relaxed(val, mc->reg_ch_base + M10V_XDTBC);

	val = md->src;
	writel_relaxed(val, mc->reg_ch_base + M10V_XDSSA);

	val = md->dst;
	writel_relaxed(val, mc->reg_ch_base + M10V_XDDSA);

	val = readl_relaxed(mc->reg_ch_base + M10V_XDSAC);
	val &= ~(M10V_XDSAC_SBS | M10V_XDSAC_SBL);
	val |= FIELD_PREP(M10V_XDSAC_SBS, M10V_DEFBS) |
		FIELD_PREP(M10V_XDSAC_SBL, M10V_DEFBL);
	writel_relaxed(val, mc->reg_ch_base + M10V_XDSAC);

	val = readl_relaxed(mc->reg_ch_base + M10V_XDDAC);
	val &= ~(M10V_XDDAC_DBS | M10V_XDDAC_DBL);
	val |= FIELD_PREP(M10V_XDDAC_DBS, M10V_DEFBS) |
		FIELD_PREP(M10V_XDDAC_DBL, M10V_DEFBL);
	writel_relaxed(val, mc->reg_ch_base + M10V_XDDAC);

	/* Start the channel */
	val = readl_relaxed(mc->reg_ch_base + M10V_XDDES);
	val &= ~(M10V_XDDES_CE | M10V_XDDES_SE | M10V_XDDES_TF |
		 M10V_XDDES_EI | M10V_XDDES_TI);
	val |= FIELD_PREP(M10V_XDDES_CE, 1) | FIELD_PREP(M10V_XDDES_SE, 1) |
		FIELD_PREP(M10V_XDDES_TF, 1) | FIELD_PREP(M10V_XDDES_EI, 1) |
		FIELD_PREP(M10V_XDDES_TI, 1);
	writel_relaxed(val, mc->reg_ch_base + M10V_XDDES);
}

/* mc->vc.lock must be held by caller */
static void milbeaut_xdmac_start(struct milbeaut_xdmac_chan *mc)

Annotation

Implementation Notes