drivers/mmc/core/sd_ops.c

Source file repositories/reference/linux-study-clean/drivers/mmc/core/sd_ops.c

File Facts

System
Linux kernel
Corpus path
drivers/mmc/core/sd_ops.c
Extension
.c
Size
8620 bytes
Lines
420
Domain
Driver Families
Bucket
drivers/mmc
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 sd_app_op_cond_busy_data {
	struct mmc_host *host;
	u32 ocr;
	struct mmc_command *cmd;
};

int mmc_app_cmd(struct mmc_host *host, struct mmc_card *card)
{
	int err;
	struct mmc_command cmd = {};

	if (WARN_ON(card && card->host != host))
		return -EINVAL;

	/*
	 * UHS2 packet has APP bit so only set APP_CMD flag here.
	 * Will set the APP bit when assembling UHS2 packet.
	 */
	if (host->uhs2_sd_tran) {
		host->uhs2_app_cmd = true;
		return 0;
	}

	cmd.opcode = MMC_APP_CMD;

	if (card) {
		cmd.arg = card->rca << 16;
		cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_AC;
	} else {
		cmd.arg = 0;
		cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_BCR;
	}

	err = mmc_wait_for_cmd(host, &cmd, 0);
	if (err)
		return err;

	/* Check that card supported application commands */
	if (!mmc_host_is_spi(host) && !(cmd.resp[0] & R1_APP_CMD))
		return -EOPNOTSUPP;

	return 0;
}
EXPORT_SYMBOL_GPL(mmc_app_cmd);

static int mmc_wait_for_app_cmd(struct mmc_host *host, struct mmc_card *card,
				struct mmc_command *cmd)
{
	struct mmc_request mrq = {};
	int i, err = -EIO;

	/*
	 * We have to resend MMC_APP_CMD for each attempt so
	 * we cannot use the retries field in mmc_command.
	 */
	for (i = 0; i <= MMC_CMD_RETRIES; i++) {
		err = mmc_app_cmd(host, card);
		if (err) {
			/* no point in retrying; no APP commands allowed */
			if (mmc_host_is_spi(host)) {
				if (cmd->resp[0] & R1_SPI_ILLEGAL_COMMAND)
					break;
			}
			continue;
		}

		memset(&mrq, 0, sizeof(struct mmc_request));

		memset(cmd->resp, 0, sizeof(cmd->resp));
		cmd->retries = 0;

		mrq.cmd = cmd;
		cmd->data = NULL;

		mmc_wait_for_req(host, &mrq);

		err = cmd->error;
		if (!cmd->error)
			break;

		/* no point in retrying illegal APP commands */
		if (mmc_host_is_spi(host)) {
			if (cmd->resp[0] & R1_SPI_ILLEGAL_COMMAND)
				break;
		}
	}

	return err;
}

Annotation

Implementation Notes