emmc: add kernel wr interface: rk_emmc_transfer

drivers/mmc/card/block.c

@@ -1963,6 +1963,9 @@ static const struct mmc_fixup blk_fixups[] =
 	END_FIXUP
 };
 
+#ifdef CONFIG_EMMC_RK
+extern struct mmc_card *this_card;
+#endif
 static int mmc_blk_probe(struct mmc_card *card)
 {
 	struct mmc_blk_data *md, *part_md;
@@ -2005,6 +2008,9 @@ static int mmc_blk_probe(struct mmc_card *card)
 		if (mmc_add_disk(part_md))
 			goto out;
 	}
+#ifdef CONFIG_EMMC_RK
+	this_card = card;
+#endif
 	return 0;
 
  out:
@@ -2017,6 +2023,9 @@ static void mmc_blk_remove(struct mmc_card *card)
 {
 	struct mmc_blk_data *md = mmc_get_drvdata(card);
 
+#ifdef CONFIG_EMMC_RK
+	this_card = NULL;
+#endif
 	mmc_blk_remove_parts(card, md);
 	mmc_claim_host(card->host);
 	mmc_blk_part_switch(card, md);

drivers/mmc/host/Makefile

@@ -8,7 +8,7 @@ else
 obj-$(CONFIG_SDMMC_RK29)	+= rk29_sdmmc.o
 endif
 
-obj-$(CONFIG_EMMC_RK)          += rkemmc.o
+obj-$(CONFIG_EMMC_RK)           += rkemmc.o rkemmc_ops.o
 obj-$(CONFIG_MMC_ARMMMCI)	+= mmci.o
 obj-$(CONFIG_MMC_PXA)		+= pxamci.o
 obj-$(CONFIG_MMC_IMX)		+= imxmmc.o

drivers/mmc/host/rkemmc_ops.c

@@ -0,0 +1,147 @@
+/*
+ *  linux/drivers/mmchost/rkemmc_ops.c
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or (at
+ * your option) any later version.
+ */
+
+#include <linux/mmc/core.h>
+#include <linux/mmc/card.h>
+#include <linux/mmc/host.h>
+#include <linux/mmc/mmc.h>
+#include <linux/slab.h>
+
+#include <linux/scatterlist.h>
+#include <linux/swap.h>		/* For nr_free_buffer_pages() */
+#include <linux/list.h>
+
+#include <linux/debugfs.h>
+#include <linux/uaccess.h>
+#include <linux/seq_file.h>
+#include <linux/mutex.h>
+#include <linux/miscdevice.h>
+
+#define BLKSZ		512
+
+struct mmc_card	*this_card = NULL;
+/*
+ * Fill in the mmc_request structure given a set of transfer parameters.
+ */
+static void rk_emmc_prepare_mrq(struct mmc_request *mrq, struct scatterlist *sg, 
+		unsigned sg_len, unsigned dev_addr, unsigned blocks, unsigned blksz, int write)
+{
+	BUG_ON(!mrq || !mrq->cmd || !mrq->data || !mrq->stop);
+
+	if (blocks > 1) {
+		mrq->cmd->opcode = write ?
+			MMC_WRITE_MULTIPLE_BLOCK : MMC_READ_MULTIPLE_BLOCK;
+	} else {
+		mrq->cmd->opcode = write ?
+			MMC_WRITE_BLOCK : MMC_READ_SINGLE_BLOCK;
+	}
+
+	mrq->cmd->arg = dev_addr;
+	if (!mmc_card_blockaddr(this_card))
+		mrq->cmd->arg <<= 9;
+
+	mrq->cmd->flags = MMC_RSP_R1 | MMC_CMD_ADTC;
+
+	if (blocks == 1)
+		mrq->stop = NULL;
+	else {
+		mrq->stop->opcode = MMC_STOP_TRANSMISSION;
+		mrq->stop->arg = 0;
+		mrq->stop->flags = MMC_RSP_R1B | MMC_CMD_AC;
+	}
+
+	mrq->data->blksz = blksz;
+	mrq->data->blocks = blocks;
+	mrq->data->flags = write ? MMC_DATA_WRITE : MMC_DATA_READ;
+	mrq->data->sg = sg;
+	mrq->data->sg_len = sg_len;
+	mmc_set_data_timeout(mrq->data, this_card);
+}
+
+static int rk_emmc_busy(struct mmc_command *cmd)
+{
+	return !(cmd->resp[0] & R1_READY_FOR_DATA) ||
+		(R1_CURRENT_STATE(cmd->resp[0]) == 7);
+}
+
+/*
+ * Wait for the card to finish the busy state
+ */
+static int rk_emmc_wait_busy(void)
+{
+	int ret, busy;
+	struct mmc_command cmd = {0};
+
+	busy = 0;
+	do {
+		memset(&cmd, 0, sizeof(struct mmc_command));
+
+		cmd.opcode = MMC_SEND_STATUS;
+		cmd.arg = this_card->rca << 16;
+		cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;
+
+		ret = mmc_wait_for_cmd(this_card->host, &cmd, 0);
+		if (ret)
+			break;
+
+		if (!busy && rk_emmc_busy(&cmd)) {
+			busy = 1;
+			if (this_card->host->caps & MMC_CAP_WAIT_WHILE_BUSY)
+				pr_info("%s: Warning: Host did not "
+					"wait for busy state to end.\n",
+					mmc_hostname(this_card->host));
+		}
+	} while (rk_emmc_busy(&cmd));
+
+	return ret;
+}
+
+/*
+ * Transfer a single sector of kernel addressable data
+ */
+int rk_emmc_transfer(u8 *buffer, unsigned addr, unsigned blksz, int write)
+{
+	int ret = 0;
+
+	struct mmc_request mrq = {0};
+	struct mmc_command cmd = {0};
+	struct mmc_command stop = {0};
+	struct mmc_data data = {0};
+
+	struct scatterlist sg;
+
+	if(!this_card)
+		return -EIO;
+
+	mrq.cmd = &cmd;
+	mrq.data = &data;
+	mrq.stop = &stop;
+
+	sg_init_one(&sg, buffer, blksz);
+
+	rk_emmc_prepare_mrq(&mrq, &sg, 1, addr, 1, blksz, write);
+
+	mmc_claim_host(this_card->host);
+	mmc_wait_for_req(this_card->host, &mrq);
+
+	if (cmd.error){
+		ret = cmd.error;
+		goto exit;
+	}
+	if (data.error){
+		ret =  data.error;
+		goto exit;
+	}
+
+	ret = rk_emmc_wait_busy();
+exit:
+	mmc_release_host(this_card->host);
+	return ret;
+}
+EXPORT_SYMBOL(rk_emmc_transfer);