2013-07-21 06:59:56

by Joel Fernandes

[permalink] [raw]
Subject: [RFC 3/5] ARM: edma: Add function to manually trigger an EDMA channel

Manual trigger for events missed as a result of splitting a
scatter gather list and DMA'ing it in batches. Add a helper
function to trigger a channel incase any such events are missed.

Signed-off-by: Joel Fernandes <[email protected]>
---
arch/arm/common/edma.c | 21 +++++++++++++++++++++
include/linux/platform_data/edma.h | 2 ++
2 files changed, 23 insertions(+)

diff --git a/arch/arm/common/edma.c b/arch/arm/common/edma.c
index 3567ba1..205f5da 100644
--- a/arch/arm/common/edma.c
+++ b/arch/arm/common/edma.c
@@ -1236,6 +1236,27 @@ void edma_resume(unsigned channel)
}
EXPORT_SYMBOL(edma_resume);

+int edma_manual_trigger(unsigned channel)
+{
+ unsigned ctlr;
+ int j;
+ unsigned int mask;
+
+ ctlr = EDMA_CTLR(channel);
+ channel = EDMA_CHAN_SLOT(channel);
+ mask = BIT(channel & 0x1f);
+
+ j = channel >> 5;
+
+ /* EDMA channels without event association */
+ edma_shadow0_write_array(ctlr, SH_ESR, j, mask);
+
+ pr_debug("EDMA: ESR%d %08x\n", j,
+ edma_shadow0_read_array(ctlr, SH_ESR, j));
+ return 0;
+}
+EXPORT_SYMBOL(edma_manual_trigger);
+
/**
* edma_start - start dma on a channel
* @channel: channel being activated
diff --git a/include/linux/platform_data/edma.h b/include/linux/platform_data/edma.h
index 57300fd..0e11eca 100644
--- a/include/linux/platform_data/edma.h
+++ b/include/linux/platform_data/edma.h
@@ -180,4 +180,6 @@ struct edma_soc_info {
const s16 (*xbar_chans)[2];
};

+int edma_manual_trigger(unsigned);
+
#endif
--
1.7.9.5