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authorStefan Roese2015-06-29 14:58:09 +0200
committerLuka Perkov2015-07-10 14:54:05 +0200
commit492d3223b076a9705b64897a061b60720f50d18b (patch)
tree3455f430d9b228e1e49cf8afd4ee1d021b141cf7 /drivers
parent29905a451b7ecf86785a4404e926fb14a8daced3 (diff)
mmc: sdhci.c: Add config option to use a fixed buffer for transfers
While implementing SDIO/MMC SPL booting for the Marvell Armada 38x, the following problem occured. The SPL runs in internal SRAM which is the L2 cache locked to memory. When the MMC buffers now are located on the stack (or bss), the SDIO controller (SDHCI) can't write into this L2 cache memory. This patch introduces a method to use a fixed buffer that will be used for all transfers by defining CONFIG_FIXED_SDHCI_ALIGNED_BUFFER. This way, the board can use this buffer address located in SDRAM for all transfers. This solves this SPL problem on the A38x and should only be used in the SPL U-Boot version. Tested for SPL booting on Marvell Armada 38x DB-88F6820-GP board. Signed-off-by: Stefan Roese <sr@denx.de> Cc: Pantelis Antoniou <panto@antoniou-consulting.com> Cc: Luka Perkov <luka.perkov@sartura.hr>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/mmc/sdhci.c15
1 files changed, 15 insertions, 0 deletions
diff --git a/drivers/mmc/sdhci.c b/drivers/mmc/sdhci.c
index f72536b2aa4..d89e3028417 100644
--- a/drivers/mmc/sdhci.c
+++ b/drivers/mmc/sdhci.c
@@ -13,7 +13,11 @@
#include <mmc.h>
#include <sdhci.h>
+#if defined(CONFIG_FIXED_SDHCI_ALIGNED_BUFFER)
+void *aligned_buffer = (void *)CONFIG_FIXED_SDHCI_ALIGNED_BUFFER;
+#else
void *aligned_buffer;
+#endif
static void sdhci_reset(struct sdhci_host *host, u8 mask)
{
@@ -205,6 +209,17 @@ static int sdhci_send_command(struct mmc *mmc, struct mmc_cmd *cmd,
memcpy(aligned_buffer, data->src, trans_bytes);
}
+#if defined(CONFIG_FIXED_SDHCI_ALIGNED_BUFFER)
+ /*
+ * Always use this bounce-buffer when
+ * CONFIG_FIXED_SDHCI_ALIGNED_BUFFER is defined
+ */
+ is_aligned = 0;
+ start_addr = (unsigned long)aligned_buffer;
+ if (data->flags != MMC_DATA_READ)
+ memcpy(aligned_buffer, data->src, trans_bytes);
+#endif
+
sdhci_writel(host, start_addr, SDHCI_DMA_ADDRESS);
mode |= SDHCI_TRNS_DMA;
#endif