2012-09-01 03:58:05

by Hein_Tibosch

[permalink] [raw]
Subject: [PATCH v3 3/3] avr32: at32ap700x: set DMA slave properties for MCI dw_dmac

The MCI makes use of the dw_dmac driver when DMA is being used.
Due to recent changes to dw_dmac the MCI+DMA driver was broken because:
- a patch in dw_dmac allowed for 64-bit transfers on the memory side, giving
an illegal value of 3 in the SRC/DST_TR_WIDTH register
(http://lkml.org/lkml/2012/1/18/52)
- the SMS field in the CTLL register received the wrong value 0

This patch sets the SMS (Source Master Select) to 1 and limits
the maximum transfer width to 32 bits.

Note: this can only be applied after the previous:
[PATCH v3 2/3] dw_dmac: max_mem_width limits value for SRC/DST_TR_WID register

Signed-off-by: Hein Tibosch <[email protected]>
Acked-by: Hans-Christian Egtvedt <[email protected]>
---
arch/avr32/mach-at32ap/at32ap700x.c | 5 +++++
1 files changed, 5 insertions(+), 0 deletions(-)

diff --git a/arch/avr32/mach-at32ap/at32ap700x.c b/arch/avr32/mach-at32ap/at32ap700x.c
index 0445c4f..7250c70 100644
--- a/arch/avr32/mach-at32ap/at32ap700x.c
+++ b/arch/avr32/mach-at32ap/at32ap700x.c
@@ -1356,6 +1356,11 @@ at32_add_device_mci(unsigned int id, struct mci_platform_data *data)
slave->sdata.cfg_lo &= ~(DWC_CFGL_HS_DST_POL
| DWC_CFGL_HS_SRC_POL);

+ /* Setup DMA controller: let source be master */
+ slave->sdata.src_master = 1;
+ /* Limit maximum transfer width to 32-bit */
+ slave->sdata.max_mem_width = DW_MEM_WIDTH_32;
+
data->dma_slave = slave;

if (platform_device_add_data(pdev, data,
--
1.7.8.0