[resend][PATCH 15/16] dma: dw_dmac: add dwc_chan_pause and dwc_chan_resume

From: Andy Shevchenko
Date: Wed Jan 09 2013 - 03:18:35 EST


We will use at least the dwc_chan_resume() later.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Acked-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
---
drivers/dma/dw_dmac.c | 31 ++++++++++++++++++++++---------
1 file changed, 22 insertions(+), 9 deletions(-)

diff --git a/drivers/dma/dw_dmac.c b/drivers/dma/dw_dmac.c
index 8afbda6..6a8f8c7 100644
--- a/drivers/dma/dw_dmac.c
+++ b/drivers/dma/dw_dmac.c
@@ -1008,6 +1008,26 @@ set_runtime_config(struct dma_chan *chan, struct dma_slave_config *sconfig)
return 0;
}

+static inline void dwc_chan_pause(struct dw_dma_chan *dwc)
+{
+ u32 cfglo = channel_readl(dwc, CFG_LO);
+
+ channel_writel(dwc, CFG_LO, cfglo | DWC_CFGL_CH_SUSP);
+ while (!(channel_readl(dwc, CFG_LO) & DWC_CFGL_FIFO_EMPTY))
+ cpu_relax();
+
+ dwc->paused = true;
+}
+
+static inline void dwc_chan_resume(struct dw_dma_chan *dwc)
+{
+ u32 cfglo = channel_readl(dwc, CFG_LO);
+
+ channel_writel(dwc, CFG_LO, cfglo & ~DWC_CFGL_CH_SUSP);
+
+ dwc->paused = false;
+}
+
static int dwc_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
unsigned long arg)
{
@@ -1015,18 +1035,13 @@ static int dwc_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
struct dw_dma *dw = to_dw_dma(chan->device);
struct dw_desc *desc, *_desc;
unsigned long flags;
- u32 cfglo;
LIST_HEAD(list);

if (cmd == DMA_PAUSE) {
spin_lock_irqsave(&dwc->lock, flags);

- cfglo = channel_readl(dwc, CFG_LO);
- channel_writel(dwc, CFG_LO, cfglo | DWC_CFGL_CH_SUSP);
- while (!(channel_readl(dwc, CFG_LO) & DWC_CFGL_FIFO_EMPTY))
- cpu_relax();
+ dwc_chan_pause(dwc);

- dwc->paused = true;
spin_unlock_irqrestore(&dwc->lock, flags);
} else if (cmd == DMA_RESUME) {
if (!dwc->paused)
@@ -1034,9 +1049,7 @@ static int dwc_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,

spin_lock_irqsave(&dwc->lock, flags);

- cfglo = channel_readl(dwc, CFG_LO);
- channel_writel(dwc, CFG_LO, cfglo & ~DWC_CFGL_CH_SUSP);
- dwc->paused = false;
+ dwc_chan_resume(dwc);

spin_unlock_irqrestore(&dwc->lock, flags);
} else if (cmd == DMA_TERMINATE_ALL) {
--
1.7.10.4

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