diff mbox series

[v6,2/4] mmc: sdhci: add quirks for be to le byte swapping

Message ID 20200518191742.1251440-2-angelo.dureghello@timesys.com
State Superseded
Headers show
Series None | expand

Commit Message

Angelo Dureghello May 18, 2020, 7:17 p.m. UTC 
Some controller as the ColdFire eshdc may require an endianness
byte swap, because DMA read endianness is not configurable.

Facilitate using the bounce buffer for this by adding
->copy_to_bounce_buffer().

Signed-off-by: Angelo Dureghello <angelo.dureghello@timesys.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
---
Changes for v3:
- add post request callback
Changes for v4:
none
Changes for v5:
- remove useless comment before swapping bounce buffer
- rename pre_dma_transfer to copy_to_bounce_buffer
Changes for v6:
- add more details in the commit message body
- add length parameter to copy_to_bounce_buffer()
---
 drivers/mmc/host/sdhci.c | 10 +++++++---
 drivers/mmc/host/sdhci.h |  3 +++
 2 files changed, 10 insertions(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 3f716466fcfd..99613f9891a3 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -634,9 +634,13 @@  static int sdhci_pre_dma_transfer(struct sdhci_host *host,
 		}
 		if (mmc_get_dma_dir(data) == DMA_TO_DEVICE) {
 			/* Copy the data to the bounce buffer */
-			sg_copy_to_buffer(data->sg, data->sg_len,
-					  host->bounce_buffer,
-					  length);
+			if (host->ops->copy_to_bounce_buffer) {
+				host->ops->copy_to_bounce_buffer(host,
+								 data, length);
+			} else {
+				sg_copy_to_buffer(data->sg, data->sg_len,
+						  host->bounce_buffer, length);
+			}
 		}
 		/* 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..1bf4f1d91951 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -653,6 +653,9 @@  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	(*copy_to_bounce_buffer)(struct sdhci_host *host,
+					 struct mmc_data *data,
+					 unsigned int length);
 	void	(*request_done)(struct sdhci_host *host,
 				struct mmc_request *mrq);
 };