From 693e5e2025278d90e1427f037e5ec8ea1ec7d5c4 Mon Sep 17 00:00:00 2001 From: Nicolas Ferre Date: Wed, 6 Jun 2012 12:19:44 +0200 Subject: 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 Signed-off-by: Ludovic Desroches Signed-off-by: Chris Ball --- drivers/mmc/host/atmel-mci-regs.h | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'drivers/mmc/host/atmel-mci-regs.h') diff --git a/drivers/mmc/host/atmel-mci-regs.h b/drivers/mmc/host/atmel-mci-regs.h index 787aba1682b..ab56f7db531 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__ */ -- cgit v1.2.3-18-g5258