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authorNicolas Ferre <nicolas.ferre@atmel.com>2012-06-06 12:19:44 +0200
committerChris Ball <cjb@laptop.org>2012-06-06 08:52:12 -0400
commit693e5e2025278d90e1427f037e5ec8ea1ec7d5c4 (patch)
tree00ff2b11eeb9f828c7efebe0921ca7f2e655858d /drivers/mmc/host/atmel-mci-regs.h
parentb87cc1b5d3a96ef9f1b3a4f8ce7aaff18e96c994 (diff)
downloadop-kernel-dev-693e5e2025278d90e1427f037e5ec8ea1ec7d5c4.zip
op-kernel-dev-693e5e2025278d90e1427f037e5ec8ea1ec7d5c4.tar.gz
mmc: atmel-mci: fix burst/chunk size modification
The use of DMA slave config operation requires that the burst size (aka chunk size) is specified through this interface. Modify atmel-mci slave driver to use this specification on its side. Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com> Signed-off-by: Chris Ball <cjb@laptop.org>
Diffstat (limited to 'drivers/mmc/host/atmel-mci-regs.h')
-rw-r--r--drivers/mmc/host/atmel-mci-regs.h14
1 files changed, 14 insertions, 0 deletions
diff --git a/drivers/mmc/host/atmel-mci-regs.h b/drivers/mmc/host/atmel-mci-regs.h
index 787aba1..ab56f7d 100644
--- a/drivers/mmc/host/atmel-mci-regs.h
+++ b/drivers/mmc/host/atmel-mci-regs.h
@@ -140,4 +140,18 @@
#define atmci_writel(port,reg,value) \
__raw_writel((value), (port)->regs + reg)
+/*
+ * Fix sconfig's burst size according to atmel MCI. We need to convert them as:
+ * 1 -> 0, 4 -> 1, 8 -> 2, 16 -> 3.
+ *
+ * This can be done by finding most significant bit set.
+ */
+static inline unsigned int atmci_convert_chksize(unsigned int maxburst)
+{
+ if (maxburst > 1)
+ return fls(maxburst) - 2;
+ else
+ return 0;
+}
+
#endif /* __DRIVERS_MMC_ATMEL_MCI_H__ */
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