[PATCH 1/3] DMAENGINE: DMA40 support paused channel status

From: Linus Walleij
Date: Mon May 17 2010 - 18:41:00 EST


From: Jonas Aaberg <jonas.aberg@xxxxxxxxxxxxxx>

Support determining whether a channel is paused or
not using the status function.

Signed-off-by: Jonas Aaberg <jonas.aberg@xxxxxxxxxxxxxx>
Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxxxxxx>
---
The majority of this patch was a bugfix for the PrimeCell
extensions which included the paused channel status. This
breaks out that small generic part and integrates the bugfix
patch.
---
drivers/dma/ste_dma40.c | 75 ++++++++++++++++++++++++++++++++++++++++++-----
1 files changed, 67 insertions(+), 8 deletions(-)

diff --git a/drivers/dma/ste_dma40.c b/drivers/dma/ste_dma40.c
index e4295a2..16a7d2b 100644
--- a/drivers/dma/ste_dma40.c
+++ b/drivers/dma/ste_dma40.c
@@ -659,7 +659,7 @@ static void d40_config_set_event(struct d40_chan *d40c, bool do_enable)
spin_unlock_irqrestore(&d40c->phy_chan->lock, flags);
}

-static bool d40_chan_has_events(struct d40_chan *d40c)
+static u32 d40_chan_has_events(struct d40_chan *d40c)
{
u32 val = 0;

@@ -674,7 +674,7 @@ static bool d40_chan_has_events(struct d40_chan *d40c)
val = readl(d40c->base->virtbase + D40_DREG_PCBASE +
d40c->phy_chan->num * D40_DREG_PCDELTA +
D40_CHAN_REG_SDLNK);
- return (bool) val;
+ return val;
}

static void d40_config_enable_lidx(struct d40_chan *d40c)
@@ -1389,6 +1389,65 @@ static int d40_pause(struct dma_chan *chan)
return res;
}

+static bool d40_is_paused(struct d40_chan *d40c)
+{
+ bool is_paused = false;
+ unsigned long flags;
+ void __iomem *active_reg;
+ u32 status;
+ u32 event;
+ int res;
+
+ spin_lock_irqsave(&d40c->lock, flags);
+
+ if (d40c->log_num == D40_PHY_CHAN) {
+ if (d40c->phy_chan->num % 2 == 0)
+ active_reg = d40c->base->virtbase + D40_DREG_ACTIVE;
+ else
+ active_reg = d40c->base->virtbase + D40_DREG_ACTIVO;
+
+ status = (readl(active_reg) &
+ D40_CHAN_POS_MASK(d40c->phy_chan->num)) >>
+ D40_CHAN_POS(d40c->phy_chan->num);
+ if (status == D40_DMA_SUSPENDED || status == D40_DMA_STOP)
+ is_paused = true;
+
+ goto _exit;
+ }
+
+ res = d40_channel_execute_command(d40c, D40_DMA_SUSPEND_REQ);
+ if (res != 0)
+ goto _exit;
+
+ if (d40c->dma_cfg.dir == STEDMA40_MEM_TO_PERIPH ||
+ d40c->dma_cfg.dir == STEDMA40_MEM_TO_MEM)
+ event = D40_TYPE_TO_EVENT(d40c->dma_cfg.dst_dev_type);
+ else if (d40c->dma_cfg.dir == STEDMA40_PERIPH_TO_MEM)
+ event = D40_TYPE_TO_EVENT(d40c->dma_cfg.src_dev_type);
+ else {
+ dev_err(&d40c->chan.dev->device,
+ "[%s] Unknown direction\n", __func__);
+ goto _exit;
+ }
+ status = d40_chan_has_events(d40c);
+ status = (status & D40_EVENTLINE_MASK(event)) >>
+ D40_EVENTLINE_POS(event);
+
+ if (status != D40_DMA_RUN)
+ is_paused = true;
+
+ /* Resume the other logical channels if any */
+ if (d40_chan_has_events(d40c))
+ res = d40_channel_execute_command(d40c,
+ D40_DMA_RUN);
+
+_exit:
+ spin_unlock_irqrestore(&d40c->lock, flags);
+ return is_paused;
+
+}
+
+
static bool d40_tx_is_linked(struct d40_chan *d40c)
{
bool is_link;
@@ -1980,13 +2039,13 @@ static enum dma_status d40_tx_status(struct dma_chan *chan,
last_complete = d40c->completed;
last_used = chan->cookie;

- ret = dma_async_is_complete(cookie, last_complete, last_used);
+ if (d40_is_paused(d40c))
+ ret = DMA_PAUSED;
+ else
+ ret = dma_async_is_complete(cookie, last_complete, last_used);

- if (txstate) {
- txstate->last = last_complete;
- txstate->used = last_used;
- txstate->residue = stedma40_residue(chan);
- }
+ dma_set_tx_state(txstate, last_complete, last_used,
+ stedma40_residue(chan));

return ret;
}
--
1.7.0.1

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