From 03a8890ee098e00f8b3c89c2d7f134ed4b89b68c Mon Sep 17 00:00:00 2001
From: =?utf8?q?Lothar=20Wa=C3=9Fmann?= <LW@KARO-electronics.de>
Date: Wed, 3 Sep 2014 13:57:07 +0200
Subject: [PATCH] MX28: DMA: make the DMA timeout configurable

Use the default value from commit 1375f044d96f "MX28: DMA: Prolong the DMA timeout",
but let users change it depending on the amount of data to be
transferred and the expected data rate.
---
 arch/arm/include/asm/imx-common/dma.h |  3 ++
 drivers/dma/apbh_dma.c                | 56 +++++++++++++++++++++++++--
 2 files changed, 55 insertions(+), 4 deletions(-)

diff --git a/arch/arm/include/asm/imx-common/dma.h b/arch/arm/include/asm/imx-common/dma.h
index 5f516ef6e0..14a0c12ddc 100644
--- a/arch/arm/include/asm/imx-common/dma.h
+++ b/arch/arm/include/asm/imx-common/dma.h
@@ -150,11 +150,14 @@ struct mxs_dma_chan {
 	unsigned int pending_num;
 	struct list_head active;
 	struct list_head done;
+	unsigned long timeout;
 };
 
 struct mxs_dma_desc *mxs_dma_desc_alloc(void);
 void mxs_dma_desc_free(struct mxs_dma_desc *);
 int mxs_dma_desc_append(int channel, struct mxs_dma_desc *pdesc);
+int mxs_dma_set_timeout(int channel, unsigned long timeout);
+unsigned long mxs_dma_get_timeout(int channel);
 
 int mxs_dma_go(int chan);
 void mxs_dma_init(void);
diff --git a/drivers/dma/apbh_dma.c b/drivers/dma/apbh_dma.c
index 042e0ef5fb..eab87bc9f4 100644
--- a/drivers/dma/apbh_dma.c
+++ b/drivers/dma/apbh_dma.c
@@ -290,6 +290,7 @@ static int mxs_dma_request(int channel)
 	pchan->flags |= MXS_DMA_FLAGS_ALLOCATED;
 	pchan->active_num = 0;
 	pchan->pending_num = 0;
+	pchan->timeout = 10000000;
 
 	INIT_LIST_HEAD(&pchan->active);
 	INIT_LIST_HEAD(&pchan->done);
@@ -327,6 +328,44 @@ int mxs_dma_release(int channel)
 	return 0;
 }
 
+/*
+ * Set the timeout for any DMA operation started with mxs_dma_go()
+ * The timeout value given is in milliseconds
+ */
+int mxs_dma_set_timeout(int channel, unsigned long timeout)
+{
+	int ret;
+	struct mxs_dma_chan *pchan;
+
+	ret = mxs_dma_validate_chan(channel);
+	if (ret)
+		return ret;
+
+	pchan = &mxs_dma_channels[channel];
+
+	if (pchan->flags & MXS_DMA_FLAGS_BUSY)
+		return -EBUSY;
+
+	if (timeout > ~0UL / 1000)
+		return -EINVAL;
+
+	pchan->timeout = timeout;
+	return 0;
+}
+
+unsigned long mxs_dma_get_timeout(int channel)
+{
+	int ret;
+	struct mxs_dma_chan *pchan;
+
+	ret = mxs_dma_validate_chan(channel);
+	if (ret)
+		return 0;
+
+	pchan = &mxs_dma_channels[channel];
+	return pchan->timeout;
+}
+
 /*
  * Allocate DMA descriptor
  */
@@ -513,16 +552,25 @@ static int mxs_dma_wait_complete(uint32_t timeout, unsigned int chan)
  */
 int mxs_dma_go(int chan)
 {
-	uint32_t timeout = 10000;
 	int ret;
-
+	struct mxs_dma_chan *pchan;
 	LIST_HEAD(tmp_desc_list);
 
+	ret = mxs_dma_validate_chan(chan);
+	if (ret)
+		return ret;
+
+	pchan = &mxs_dma_channels[chan];
+
 	mxs_dma_enable_irq(chan, 1);
-	mxs_dma_enable(chan);
+	ret = mxs_dma_enable(chan);
+	if (ret) {
+		mxs_dma_enable_irq(chan, 0);
+		return ret;
+	}
 
 	/* Wait for DMA to finish. */
-	ret = mxs_dma_wait_complete(timeout, chan);
+	ret = mxs_dma_wait_complete(pchan->timeout * 1000, chan);
 
 	/* Clear out the descriptors we just ran. */
 	mxs_dma_finish(chan, &tmp_desc_list);
-- 
2.39.2