[PATCH v3 2/3] mmc: sdhci: add quirks for be to le byte swapping

[Angelo Dureghello <angelo.dureghello@timesys.com>]

Some controller as the ColdFire eshdc may require an endianness
byte swap, becouse DMA read endianness is not configurable.

Signed-off-by: Angelo Dureghello <angelo.dureghello@timesys.com>
---
Changes for v3:
- add post request callback
---
 drivers/mmc/host/sdhci.c | 7 +++++++
 drivers/mmc/host/sdhci.h | 2 ++
 2 files changed, 9 insertions(+)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 3f716466fcfd..d3bfbb6e11d5 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -637,6 +637,13 @@ static int sdhci_pre_dma_transfer(struct sdhci_host *host,
 			sg_copy_to_buffer(data->sg, data->sg_len,
 					  host->bounce_buffer,
 					  length);
+
+			/*
+			 * Endianness can't be swapped in the sg list,
+			 * since the sg list is processed again later on.
+			 */
+			if (host->ops->pre_dma_transfer)
+				host->ops->pre_dma_transfer(host, data);
 		}
 		/* Switch ownership to the DMA */
 		dma_sync_single_for_device(host->mmc->parent,
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index 79dffbb731d3..076054308423 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -653,6 +653,8 @@ struct sdhci_ops {
 	void	(*voltage_switch)(struct sdhci_host *host);
 	void	(*adma_write_desc)(struct sdhci_host *host, void **desc,
 				   dma_addr_t addr, int len, unsigned int cmd);
+	void	(*pre_dma_transfer)(struct sdhci_host *host,
+				    struct mmc_data *data);
 	void	(*request_done)(struct sdhci_host *host,
 				struct mmc_request *mrq);
 };
-- 
2.26.0