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path: root/drivers/mmc/host/sdhci-of-dwcmshc.c
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Diffstat (limited to 'drivers/mmc/host/sdhci-of-dwcmshc.c')
-rw-r--r--drivers/mmc/host/sdhci-of-dwcmshc.c39
1 files changed, 39 insertions, 0 deletions
diff --git a/drivers/mmc/host/sdhci-of-dwcmshc.c b/drivers/mmc/host/sdhci-of-dwcmshc.c
index 1b7cd144fb01..a5137845a1c7 100644
--- a/drivers/mmc/host/sdhci-of-dwcmshc.c
+++ b/drivers/mmc/host/sdhci-of-dwcmshc.c
@@ -8,21 +8,51 @@
*/
#include <linux/clk.h>
+#include <linux/dma-mapping.h>
+#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
+#include <linux/sizes.h>
#include "sdhci-pltfm.h"
+#define BOUNDARY_OK(addr, len) \
+ ((addr | (SZ_128M - 1)) == ((addr + len - 1) | (SZ_128M - 1)))
+
struct dwcmshc_priv {
struct clk *bus_clk;
};
+/*
+ * If DMA addr spans 128MB boundary, we split the DMA transfer into two
+ * so that each DMA transfer doesn't exceed the boundary.
+ */
+static void dwcmshc_adma_write_desc(struct sdhci_host *host, void **desc,
+ dma_addr_t addr, int len, unsigned int cmd)
+{
+ int tmplen, offset;
+
+ if (likely(!len || BOUNDARY_OK(addr, len))) {
+ sdhci_adma_write_desc(host, desc, addr, len, cmd);
+ return;
+ }
+
+ offset = addr & (SZ_128M - 1);
+ tmplen = SZ_128M - offset;
+ sdhci_adma_write_desc(host, desc, addr, tmplen, cmd);
+
+ addr += tmplen;
+ len -= tmplen;
+ sdhci_adma_write_desc(host, desc, addr, len, cmd);
+}
+
static const struct sdhci_ops sdhci_dwcmshc_ops = {
.set_clock = sdhci_set_clock,
.set_bus_width = sdhci_set_bus_width,
.set_uhs_signaling = sdhci_set_uhs_signaling,
.get_max_clock = sdhci_pltfm_clk_get_max_clock,
.reset = sdhci_reset,
+ .adma_write_desc = dwcmshc_adma_write_desc,
};
static const struct sdhci_pltfm_data sdhci_dwcmshc_pdata = {
@@ -36,12 +66,21 @@ static int dwcmshc_probe(struct platform_device *pdev)
struct sdhci_host *host;
struct dwcmshc_priv *priv;
int err;
+ u32 extra;
host = sdhci_pltfm_init(pdev, &sdhci_dwcmshc_pdata,
sizeof(struct dwcmshc_priv));
if (IS_ERR(host))
return PTR_ERR(host);
+ /*
+ * extra adma table cnt for cross 128M boundary handling.
+ */
+ extra = DIV_ROUND_UP_ULL(dma_get_required_mask(&pdev->dev), SZ_128M);
+ if (extra > SDHCI_MAX_SEGS)
+ extra = SDHCI_MAX_SEGS;
+ host->adma_table_cnt += extra;
+
pltfm_host = sdhci_priv(host);
priv = sdhci_pltfm_priv(pltfm_host);