[PATCH 5/7] S3C64XX DMA: TC-IRQ implemented.

[Jassi]

The available irq handler simply doesn't work. The Dma state-machine
is broken. This patch fixes it.
Also, chan->curr,next,end pointer manipulation is protected.

Signed-Off-by: Jassi <jassi.brar at samsung.com>
---
 arch/arm/plat-s3c64xx/dma.c |   61 +++++++++++++++++++++++++++---------------
 1 files changed, 39 insertions(+), 22 deletions(-)

diff --git a/arch/arm/plat-s3c64xx/dma.c b/arch/arm/plat-s3c64xx/dma.c
index 02bc82b..e68469d 100644
--- a/arch/arm/plat-s3c64xx/dma.c
+++ b/arch/arm/plat-s3c64xx/dma.c
@@ -339,6 +339,7 @@ int s3c2410_dma_enqueue(unsigned int channel, void *id,
 	struct s3c64xx_dma_buff *next;
 	struct s3c64xx_dma_buff *buff;
 	struct pl080s_lli *lli;
+	unsigned long flags;
 	int ret;
 
 	WARN_ON(!chan);
@@ -366,6 +367,8 @@ int s3c2410_dma_enqueue(unsigned int channel, void *id,
 
 	s3c64xx_dma_fill_lli(chan, lli, data, size);
 
+	local_irq_save(flags);
+
 	if ((next = chan->next) != NULL) {
 		struct s3c64xx_dma_buff *end = chan->end;
 		struct pl080s_lli *endlli = end->lli;
@@ -399,6 +402,8 @@ int s3c2410_dma_enqueue(unsigned int channel, void *id,
 		s3c64xx_lli_to_regs(chan, lli);
 	}
 
+	local_irq_restore(flags);
+
 	show_lli(lli);
 
 	dbg_showchan(chan);
@@ -562,27 +567,13 @@ int s3c2410_dma_free(unsigned int channel, struct s3c2410_dma_client *client)
 
 EXPORT_SYMBOL(s3c2410_dma_free);
 
-
-static void s3c64xx_dma_tcirq(struct s3c64xx_dmac *dmac, int offs)
-{
-	struct s3c2410_dma_chan *chan = dmac->channels + offs;
-
-	/* note, we currently do not bother to work out which buffer
-	 * or buffers have been completed since the last tc-irq. */
-
-	if (chan->callback_fn)
-		(chan->callback_fn)(chan, chan->curr->pw, 0, S3C2410_RES_OK);
-}
-
-static void s3c64xx_dma_errirq(struct s3c64xx_dmac *dmac, int offs)
-{
-	printk(KERN_DEBUG "%s: offs %d\n", __func__, offs);
-}
-
 static irqreturn_t s3c64xx_dma_irq(int irq, void *pw)
 {
+	struct s3c64xx_dma_buff *buff;
 	struct s3c64xx_dmac *dmac = pw;
-	u32 tcstat, errstat;
+	struct s3c2410_dma_chan *chan;
+	enum s3c2410_dma_buffresult res;
+	u32 tcstat, errstat, val;
 	u32 bit;
 	int offs;
 
@@ -590,15 +581,41 @@ static irqreturn_t s3c64xx_dma_irq(int irq, void *pw)
 	errstat = readl(dmac->regs + PL080_ERR_STATUS);
 
 	for (offs = 0, bit = 1; offs < 8; offs++, bit <<= 1) {
+
+		if (!(errstat & bit) && !(tcstat & bit))
+			continue;
+
+		res = S3C2410_RES_ERR;
+
+		if (errstat & bit)
+			writel(bit, dmac->regs + PL080_ERR_CLEAR);
+
 		if (tcstat & bit) {
 			writel(bit, dmac->regs + PL080_TC_CLEAR);
-			s3c64xx_dma_tcirq(dmac, offs);
+			res = S3C2410_RES_OK;
 		}
 
-		if (errstat & bit) {
-			s3c64xx_dma_errirq(dmac, offs);
-			writel(bit, dmac->regs + PL080_ERR_CLEAR);
+		chan = dmac->channels + offs;
+		if(chan->curr == NULL)
+			continue;
+
+		buff = chan->curr;
+		if (chan->curr != chan->end) {
+			BUG_ON(chan->curr->next == NULL);
+			chan->curr = chan->curr->next;
+
+			val = readl(chan->regs + PL080S_CH_CONFIG);
+			if (!(val & PL080_CONFIG_ACTIVE)) {
+				s3c64xx_lli_to_regs(chan, chan->curr->lli);
+				val |= PL080_CONFIG_ENABLE;
+				writel(val, chan->regs + PL080S_CH_CONFIG);
+			}
+		} else {
+			chan->curr = chan->next = chan->end = NULL;
 		}
+
+		s3c64xx_dma_bufffdone(chan, buff, res);
+		s3c64xx_dma_freebuff(buff);
 	}
 
 	return IRQ_HANDLED;
-- 
1.6.2.5