sdio: recognize io card without powercycle

PPH: temporal patch from Albert Herranz (no included in mainline) but necessary
for the redpine wireless module.

Original patch comments:
SDIO Simplified Specification V2.00 states that it is strongly recommended
that the host executes either a power reset or issues a CMD52 (I/O Reset) to
re-initialize an I/O only card or the I/O portion of a combo card.
Additionally, the CMD52 must be issued first because it cannot be issued
after a CMD0.

With this patch the Nintendo Wii SDIO-based WLAN card is detected after a
system reset, without requiring a complete system powercycle.

Signed-off-by: Pedro Perez de Heredia <pedro.perez@digi.com>

3 files changed, 74 insertions, 48 deletions

diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index d84c880fac84..50b208253440 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -890,6 +890,8 @@ void mmc_rescan(struct work_struct *work)
 	mmc_claim_host(host);
 
 	mmc_power_up(host);
+	sdio_go_idle(host);
+
 	mmc_go_idle(host);
 
 	mmc_send_if_cond(host, host->ocr_avail);
diff --git a/drivers/mmc/core/sdio_ops.c b/drivers/mmc/core/sdio_ops.c
index 4eb7825fd1a7..208beeb23ed6 100644
--- a/drivers/mmc/core/sdio_ops.c
+++ b/drivers/mmc/core/sdio_ops.c
@@ -67,54 +67,6 @@ int mmc_send_io_op_cond(struct mmc_host *host, u32 ocr, u32 *rocr)
 	return err;
 }
 
-int mmc_io_rw_direct(struct mmc_card *card, int write, unsigned fn,
-	unsigned addr, u8 in, u8* out)
-{
-	struct mmc_command cmd;
-	int err;
-
-	BUG_ON(!card);
-	BUG_ON(fn > 7);
-
-	/* sanity check */
-	if (addr & ~0x1FFFF)
-		return -EINVAL;
-
-	memset(&cmd, 0, sizeof(struct mmc_command));
-
-	cmd.opcode = SD_IO_RW_DIRECT;
-	cmd.arg = write ? 0x80000000 : 0x00000000;
-	cmd.arg |= fn << 28;
-	cmd.arg |= (write && out) ? 0x08000000 : 0x00000000;
-	cmd.arg |= addr << 9;
-	cmd.arg |= in;
-	cmd.flags = MMC_RSP_SPI_R5 | MMC_RSP_R5 | MMC_CMD_AC;
-
-	err = mmc_wait_for_cmd(card->host, &cmd, 0);
-	if (err)
-		return err;
-
-	if (mmc_host_is_spi(card->host)) {
-		/* host driver already reported errors */
-	} else {
-		if (cmd.resp[0] & R5_ERROR)
-			return -EIO;
-		if (cmd.resp[0] & R5_FUNCTION_NUMBER)
-			return -EINVAL;
-		if (cmd.resp[0] & R5_OUT_OF_RANGE)
-			return -ERANGE;
-	}
-
-	if (out) {
-		if (mmc_host_is_spi(card->host))
-			*out = (cmd.resp[0] >> 8) & 0xFF;
-		else
-			*out = cmd.resp[0] & 0xFF;
-	}
-
-	return 0;
-}
-
 int mmc_io_rw_extended(struct mmc_card *card, int write, unsigned fn,
 	unsigned addr, int incr_addr, u8 *buf, unsigned blocks, unsigned blksz)
 {
@@ -182,3 +134,74 @@ int mmc_io_rw_extended(struct mmc_card *card, int write, unsigned fn,
 	return 0;
 }
 
+static int mmc_io_rw_direct_host(struct mmc_host *host, int write, unsigned fn,
+	unsigned addr, u8 in, u8 *out)
+{
+	struct mmc_command cmd;
+	int err;
+
+	BUG_ON(!host);
+	BUG_ON(fn > 7);
+
+	/* sanity check */
+	if (addr & ~0x1FFFF)
+		return -EINVAL;
+
+	memset(&cmd, 0, sizeof(struct mmc_command));
+
+	cmd.opcode = SD_IO_RW_DIRECT;
+	cmd.arg = write ? 0x80000000 : 0x00000000;
+	cmd.arg |= fn << 28;
+	cmd.arg |= (write && out) ? 0x08000000 : 0x00000000;
+	cmd.arg |= addr << 9;
+	cmd.arg |= in;
+	cmd.flags = MMC_RSP_SPI_R5 | MMC_RSP_R5 | MMC_CMD_AC;
+
+	err = mmc_wait_for_cmd(host, &cmd, 0);
+	if (err)
+		return err;
+
+	if (mmc_host_is_spi(host)) {
+		/* host driver already reported errors */
+	} else {
+		if (cmd.resp[0] & R5_ERROR)
+			return -EIO;
+		if (cmd.resp[0] & R5_FUNCTION_NUMBER)
+			return -EINVAL;
+		if (cmd.resp[0] & R5_OUT_OF_RANGE)
+			return -ERANGE;
+	}
+
+	if (out) {
+		if (mmc_host_is_spi(host))
+			*out = (cmd.resp[0] >> 8) & 0xFF;
+		else
+			*out = cmd.resp[0] & 0xFF;
+	}
+
+	return 0;
+}
+
+int mmc_io_rw_direct(struct mmc_card *card, int write, unsigned fn,
+	unsigned addr, u8 in, u8 *out)
+{
+	BUG_ON(!card);
+	return mmc_io_rw_direct_host(card->host, write, fn, addr, in, out);
+}
+
+int sdio_go_idle(struct mmc_host *host)
+{
+	int ret;
+	u8 abort;
+
+	/* SDIO Simplified Specification V2.0, 4.4 Reset for SDIO */
+
+	ret = mmc_io_rw_direct_host(host, 0, 0, SDIO_CCCR_ABORT, 0, &abort);
+	if (ret)
+		abort = 0x08;
+	else
+		abort |= 0x08;
+
+	ret = mmc_io_rw_direct_host(host, 1, 0, SDIO_CCCR_ABORT, abort, NULL);
+	return ret;
+}
diff --git a/drivers/mmc/core/sdio_ops.h b/drivers/mmc/core/sdio_ops.h
index e2e74b0d17d8..9b546c71eb5e 100644
--- a/drivers/mmc/core/sdio_ops.h
+++ b/drivers/mmc/core/sdio_ops.h
@@ -17,6 +17,7 @@ int mmc_io_rw_direct(struct mmc_card *card, int write, unsigned fn,
 	unsigned addr, u8 in, u8* out);
 int mmc_io_rw_extended(struct mmc_card *card, int write, unsigned fn,
 	unsigned addr, int incr_addr, u8 *buf, unsigned blocks, unsigned blksz);
+int sdio_go_idle(struct mmc_host *host);
 
 #endif