drivers/mmc/host/cavium.c

Source file repositories/reference/linux-study-clean/drivers/mmc/host/cavium.c

File Facts

System
Linux kernel
Corpus path
drivers/mmc/host/cavium.c
Extension
.c
Size
28366 bytes
Lines
1077
Domain
Driver Families
Bucket
drivers/mmc
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

if (smi->consumed >= smi->length) {
			if (!sg_miter_next(smi))
				break;
			smi->consumed = 0;
		}

		if (shift < 0) {
			dat = readq(host->base + MIO_EMM_BUF_DAT(host));
			shift = 56;
		}

		while (smi->consumed < smi->length && shift >= 0) {
			((u8 *)smi->addr)[smi->consumed] = (dat >> shift) & 0xff;
			bytes_xfered++;
			smi->consumed++;
			shift -= 8;
		}
	}

	sg_miter_stop(smi);
	req->data->bytes_xfered = bytes_xfered;
	req->data->error = 0;
}

static void do_write(struct mmc_request *req)
{
	req->data->bytes_xfered = req->data->blocks * req->data->blksz;
	req->data->error = 0;
}

static void set_cmd_response(struct cvm_mmc_host *host, struct mmc_request *req,
			     u64 rsp_sts)
{
	u64 rsp_hi, rsp_lo;

	if (!(rsp_sts & MIO_EMM_RSP_STS_RSP_VAL))
		return;

	rsp_lo = readq(host->base + MIO_EMM_RSP_LO(host));

	switch (FIELD_GET(MIO_EMM_RSP_STS_RSP_TYPE, rsp_sts)) {
	case 1:
	case 3:
		req->cmd->resp[0] = (rsp_lo >> 8) & 0xffffffff;
		req->cmd->resp[1] = 0;
		req->cmd->resp[2] = 0;
		req->cmd->resp[3] = 0;
		break;
	case 2:
		req->cmd->resp[3] = rsp_lo & 0xffffffff;
		req->cmd->resp[2] = (rsp_lo >> 32) & 0xffffffff;
		rsp_hi = readq(host->base + MIO_EMM_RSP_HI(host));
		req->cmd->resp[1] = rsp_hi & 0xffffffff;
		req->cmd->resp[0] = (rsp_hi >> 32) & 0xffffffff;
		break;
	}
}

static int get_dma_dir(struct mmc_data *data)
{
	return (data->flags & MMC_DATA_WRITE) ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
}

static int finish_dma_single(struct cvm_mmc_host *host, struct mmc_data *data)
{
	data->bytes_xfered = data->blocks * data->blksz;
	data->error = 0;
	dma_unmap_sg(host->dev, data->sg, data->sg_len, get_dma_dir(data));
	return 1;
}

static int finish_dma_sg(struct cvm_mmc_host *host, struct mmc_data *data)
{
	u64 fifo_cfg;
	int count;

	/* Check if there are any pending requests left */
	fifo_cfg = readq(host->dma_base + MIO_EMM_DMA_FIFO_CFG(host));
	count = FIELD_GET(MIO_EMM_DMA_FIFO_CFG_COUNT, fifo_cfg);
	if (count)
		dev_err(host->dev, "%u requests still pending\n", count);

	data->bytes_xfered = data->blocks * data->blksz;
	data->error = 0;

	/* Clear and disable FIFO */
	writeq(BIT_ULL(16), host->dma_base + MIO_EMM_DMA_FIFO_CFG(host));
	dma_unmap_sg(host->dev, data->sg, data->sg_len, get_dma_dir(data));
	return 1;
}

Annotation

Implementation Notes