diff options
| author | Nicolas Ferre <nicolas.ferre@atmel.com> | 2012-06-06 12:19:44 +0200 |
|---|---|---|
| committer | Chris Ball <cjb@laptop.org> | 2012-06-06 08:52:12 -0400 |
| commit | 693e5e2025278d90e1427f037e5ec8ea1ec7d5c4 (patch) | |
| tree | 00ff2b11eeb9f828c7efebe0921ca7f2e655858d /drivers/mmc | |
| parent | b87cc1b5d3a96ef9f1b3a4f8ce7aaff18e96c994 (diff) | |
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')
| -rw-r--r-- | drivers/mmc/host/atmel-mci-regs.h | 14 | ||||
| -rw-r--r-- | drivers/mmc/host/atmel-mci.c | 8 |
2 files changed, 19 insertions, 3 deletions
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__ */ diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c index 456c077455c..f2c115e0643 100644 --- a/drivers/mmc/host/atmel-mci.c +++ b/drivers/mmc/host/atmel-mci.c @@ -910,6 +910,7 @@ atmci_prepare_data_dma(struct atmel_mci *host, struct mmc_data *data) enum dma_data_direction direction; enum dma_transfer_direction slave_dirn; unsigned int sglen; + u32 maxburst; u32 iflags; data->error = -EINPROGRESS; @@ -943,17 +944,18 @@ atmci_prepare_data_dma(struct atmel_mci *host, struct mmc_data *data) if (!chan) return -ENODEV; - if (host->caps.has_dma) - atmci_writel(host, ATMCI_DMA, ATMCI_DMA_CHKSIZE(3) | ATMCI_DMAEN); - if (data->flags & MMC_DATA_READ) { direction = DMA_FROM_DEVICE; host->dma_conf.direction = slave_dirn = DMA_DEV_TO_MEM; + maxburst = atmci_convert_chksize(host->dma_conf.src_maxburst); } else { direction = DMA_TO_DEVICE; host->dma_conf.direction = slave_dirn = DMA_MEM_TO_DEV; + maxburst = atmci_convert_chksize(host->dma_conf.dst_maxburst); } + atmci_writel(host, ATMCI_DMA, ATMCI_DMA_CHKSIZE(maxburst) | ATMCI_DMAEN); + sglen = dma_map_sg(chan->device->dev, data->sg, data->sg_len, direction); |