[PATCH] pch_dma: fix DMA issue(ch8-ch11)

From: Tomoya MORINAGA
Date: Mon May 30 2011 - 21:30:31 EST


ISSUE: In case PCH_DMA with I2S communications with ch8~ch11, sometimes I2S data
is not send correctly.
CAUSE: The following patch I submitted before was not enough modification for
supporting DMA ch8~ch11. The modification for status register of ch8~11 was not
enough.

pch_dma: Support I2S for ML7213 IOH
author Tomoya MORINAGA <tomoya-linux@xxxxxxxxxxxxxxx>
Mon, 9 May 2011 07:09:38 +0000 (16:09 +0900)
committer Vinod Koul <vinod.koul@xxxxxxxxx>
Mon, 9 May 2011 11:42:23 +0000 (16:42 +0530)
commit 194f5f2706c7472f9c6bb2d17fa788993606581f
tree c9d4903ea02b18939a4f390956a48be1a3734517
parent 60092d0bde4c8741198da4a69b693d3709385bf1

This patch fixes the issue.
We can confirm PCH_DMA with I2S communications with ch8~ch11 works well.

Signed-off-by: Tomoya MORINAGA <tomoya-linux@xxxxxxxxxxxxxxx>
---
drivers/dma/pch_dma.c | 69 +++++++++++++++++++++++++++++++++++++++----------
1 files changed, 55 insertions(+), 14 deletions(-)

diff --git a/drivers/dma/pch_dma.c b/drivers/dma/pch_dma.c
index ff5b38f..65c32f8 100644
--- a/drivers/dma/pch_dma.c
+++ b/drivers/dma/pch_dma.c
@@ -45,7 +45,8 @@
#define DMA_STATUS_MASK_BITS 0x3
#define DMA_STATUS_SHIFT_BITS 16
#define DMA_STATUS_IRQ(x) (0x1 << (x))
-#define DMA_STATUS_ERR(x) (0x1 << ((x) + 8))
+#define DMA_STATUS0_ERR(x) (0x1 << ((x) + 8))
+#define DMA_STATUS2_ERR(x) (0x1 << (x))

#define DMA_DESC_WIDTH_SHIFT_BITS 12
#define DMA_DESC_WIDTH_1_BYTE (0x3 << DMA_DESC_WIDTH_SHIFT_BITS)
@@ -133,6 +134,7 @@ struct pch_dma {
#define PCH_DMA_CTL3 0x0C
#define PCH_DMA_STS0 0x10
#define PCH_DMA_STS1 0x14
+#define PCH_DMA_STS2 0x18

#define dma_readl(pd, name) \
readl((pd)->membase + PCH_DMA_##name)
@@ -183,13 +185,19 @@ static void pdc_enable_irq(struct dma_chan *chan, int enable)
{
struct pch_dma *pd = to_pd(chan->device);
u32 val;
+ int pos;
+
+ if (chan->chan_id < 8)
+ pos = chan->chan_id;
+ else
+ pos = chan->chan_id + 8;

val = dma_readl(pd, CTL2);

if (enable)
- val |= 0x1 << chan->chan_id;
+ val |= 0x1 << pos;
else
- val &= ~(0x1 << chan->chan_id);
+ val &= ~(0x1 << pos);

dma_writel(pd, CTL2, val);

@@ -262,7 +270,7 @@ static void pdc_set_mode(struct dma_chan *chan, u32 mode)
chan->chan_id, val);
}

-static u32 pdc_get_status(struct pch_dma_chan *pd_chan)
+static u32 pdc_get_status0(struct pch_dma_chan *pd_chan)
{
struct pch_dma *pd = to_pd(pd_chan->chan.device);
u32 val;
@@ -272,9 +280,27 @@ static u32 pdc_get_status(struct pch_dma_chan *pd_chan)
DMA_STATUS_BITS_PER_CH * pd_chan->chan.chan_id));
}

+static u32 pdc_get_status2(struct pch_dma_chan *pd_chan)
+{
+ struct pch_dma *pd = to_pd(pd_chan->chan.device);
+ u32 val;
+
+ val = dma_readl(pd, STS2);
+ return DMA_STATUS_MASK_BITS & (val >> (DMA_STATUS_SHIFT_BITS +
+ DMA_STATUS_BITS_PER_CH * (pd_chan->chan.chan_id - 8)));
+}
+
static bool pdc_is_idle(struct pch_dma_chan *pd_chan)
{
- if (pdc_get_status(pd_chan) == DMA_STATUS_IDLE)
+ u32 sts;
+
+ if (pd_chan->chan.chan_id < 8)
+ sts = pdc_get_status0(pd_chan);
+ else
+ sts = pdc_get_status2(pd_chan);
+
+
+ if (sts == DMA_STATUS_IDLE)
return true;
else
return false;
@@ -693,30 +719,45 @@ static irqreturn_t pd_irq(int irq, void *devid)
struct pch_dma *pd = (struct pch_dma *)devid;
struct pch_dma_chan *pd_chan;
u32 sts0;
+ u32 sts2;
int i;
- int ret = IRQ_NONE;
+ int ret0 = IRQ_NONE;
+ int ret2 = IRQ_NONE;

sts0 = dma_readl(pd, STS0);
+ sts2 = dma_readl(pd, STS2);

dev_dbg(pd->dma.dev, "pd_irq sts0: %x\n", sts0);

for (i = 0; i < pd->dma.chancnt; i++) {
pd_chan = &pd->channels[i];

- if (sts0 & DMA_STATUS_IRQ(i)) {
- if (sts0 & DMA_STATUS_ERR(i))
- set_bit(0, &pd_chan->err_status);
+ if (i < 8) {
+ if (sts0 & DMA_STATUS_IRQ(i)) {
+ if (sts0 & DMA_STATUS0_ERR(i))
+ set_bit(0, &pd_chan->err_status);

- tasklet_schedule(&pd_chan->tasklet);
- ret = IRQ_HANDLED;
- }
+ tasklet_schedule(&pd_chan->tasklet);
+ ret0 = IRQ_HANDLED;
+ }
+ } else {
+ if (sts2 & DMA_STATUS_IRQ(i - 8)) {
+ if (sts2 & DMA_STATUS2_ERR(i))
+ set_bit(0, &pd_chan->err_status);

+ tasklet_schedule(&pd_chan->tasklet);
+ ret2 = IRQ_HANDLED;
+ }
+ }
}

/* clear interrupt bits in status register */
- dma_writel(pd, STS0, sts0);
+ if (ret0)
+ dma_writel(pd, STS0, sts0);
+ if (ret2)
+ dma_writel(pd, STS2, sts2);

- return ret;
+ return ret0 | ret2;
}

#ifdef CONFIG_PM
--
1.7.4

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