dmaengine/dw_dmac: Reconfigure interrupt and chan_cfg register on resume

In S2R all DMA registers are reset by hardware and thus they are required to be
reprogrammed. The channels which aren't reprogrammed are channel configuration
and interrupt enable registers, which are currently programmed at chan_alloc
time.

This patch creates another routine to initialize a channel. It will try to
initialize channel on every dwc_dostart() call. If channel is already
initialised then it simply returns, otherwise it configures registers.

This routine will also initialize registers on wakeup from S2R, as we mark
channels as uninitialized on suspend.

Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
cherry-picked from mainline 61e183f8306934a9f66557f69f1f0f56f18dca06

Change-Id: I4ede3e1db8844533161bd4a836b1fece0d0ee716
Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Reviewed-on: http://git-master/r/93784
Reviewed-by: Automatic_Commit_Validation_User

2 files changed, 11 insertions, 38 deletions

diff --git a/drivers/dma/dw_dmac.c b/drivers/dma/dw_dmac.c
index 36ffc4cdaf80..7fac79aadf3a 100644
--- a/drivers/dma/dw_dmac.c
+++ b/drivers/dma/dw_dmac.c
@@ -178,6 +178,7 @@ static void dwc_initialize(struct dw_dma_chan *dwc)
 
 	/* Enable interrupts */
 	channel_set_bit(dw, MASK.XFER, dwc->mask);
+	channel_set_bit(dw, MASK.BLOCK, dwc->mask);
 	channel_set_bit(dw, MASK.ERROR, dwc->mask);
 
 	dwc->initialized = true;
@@ -206,6 +207,8 @@ static void dwc_dostart(struct dw_dma_chan *dwc, struct dw_desc *first)
 		return;
 	}
 
+	dwc_initialize(dwc);
+
 	channel_writel(dwc, LLP, first->txd.phys);
 	channel_writel(dwc, CTL_LO,
 			DWC_CTLL_LLP_D_EN | DWC_CTLL_LLP_S_EN);
@@ -965,10 +968,7 @@ static int dwc_alloc_chan_resources(struct dma_chan *chan)
 	struct dw_dma_chan	*dwc = to_dw_dma_chan(chan);
 	struct dw_dma		*dw = to_dw_dma(chan->device);
 	struct dw_desc		*desc;
-	struct dw_dma_slave	*dws;
 	int			i;
-	u32			cfghi;
-	u32			cfglo;
 	unsigned long		flags;
 
 	dev_vdbg(chan2dev(chan), "alloc_chan_resources\n");
@@ -981,27 +981,6 @@ static int dwc_alloc_chan_resources(struct dma_chan *chan)
 
 	dma_cookie_init(chan);
 
-	cfghi = DWC_CFGH_FIFO_MODE;
-	cfglo = 0;
-
-	dws = chan->private;
-	if (dws) {
-		/*
-		 * We need controller-specific data to set up slave
-		 * transfers.
-		 */
-		BUG_ON(!dws->dma_dev || dws->dma_dev != dw->dma.dev);
-
-		cfghi = dws->cfg_hi;
-		cfglo = dws->cfg_lo & ~DWC_CFGL_CH_PRIOR_MASK;
-	}
-
-	cfglo |= DWC_CFGL_CH_PRIOR(dwc->priority);
-
-	channel_writel(dwc, CFG_LO, cfglo);
-	channel_writel(dwc, CFG_HI, cfghi);
-	dma_cookie_init(chan);
-
 	/*
 	 * NOTE: some controllers may have additional features that we
 	 * need to initialize here, like "scatter-gather" (which
@@ -1033,11 +1012,6 @@ static int dwc_alloc_chan_resources(struct dma_chan *chan)
 		i = ++dwc->descs_allocated;
 	}
 
-	/* Enable interrupts */
-	channel_set_bit(dw, MASK.XFER, dwc->mask);
-	channel_set_bit(dw, MASK.BLOCK, dwc->mask);
-	channel_set_bit(dw, MASK.ERROR, dwc->mask);
-
 	spin_unlock_irqrestore(&dwc->lock, flags);
 
 	dev_dbg(chan2dev(chan),
@@ -1065,6 +1039,7 @@ static void dwc_free_chan_resources(struct dma_chan *chan)
 	spin_lock_irqsave(&dwc->lock, flags);
 	list_splice_init(&dwc->free_list, &list);
 	dwc->descs_allocated = 0;
+	dwc->initialized = false;
 
 	/* Disable interrupts */
 	channel_clear_bit(dw, MASK.XFER, dwc->mask);
@@ -1342,6 +1317,8 @@ EXPORT_SYMBOL(dw_dma_cyclic_free);
 
 static void dw_dma_off(struct dw_dma *dw)
 {
+	int i;
+
 	dma_writel(dw, CFG, 0);
 
 	channel_clear_bit(dw, MASK.XFER, dw->all_chan_mask);
@@ -1352,6 +1329,9 @@ static void dw_dma_off(struct dw_dma *dw)
 
 	while (dma_readl(dw, CFG) & DW_CFG_DMA_EN)
 		cpu_relax();
+
+	for (i = 0; i < dw->dma.chancnt; i++)
+		dw->chan[i].initialized = false;
 }
 
 static int __init dw_probe(struct platform_device *pdev)
@@ -1418,17 +1398,8 @@ static int __init dw_probe(struct platform_device *pdev)
 		struct dw_dma_chan	*dwc = &dw->chan[i];
 
 		dwc->chan.device = &dw->dma;
-<<<<<<< HEAD
-		dwc->chan.chan_id = i;
-		dwc->chan.cookie = dwc->chan.completed_cookie = 1;
-=======
-<<<<<<< HEAD
-		dwc->chan.cookie = dwc->completed = 1;
 		dwc->chan.chan_id = i;
-=======
 		dma_cookie_init(&dwc->chan);
->>>>>>> d3ee98cdc... dmaengine: consolidate initialization of cookies
->>>>>>> 1e15982... dmaengine: consolidate initialization of cookies
 		if (pdata->chan_allocation_order == CHAN_ALLOCATION_ASCENDING)
 			list_add_tail(&dwc->chan.device_node,
 					&dw->dma.channels);
@@ -1550,6 +1521,7 @@ static int dw_suspend_noirq(struct device *dev)
 
 	dw_dma_off(platform_get_drvdata(pdev));
 	clk_disable(dw->clk);
+
 	return 0;
 }
 
diff --git a/drivers/dma/dw_dmac_regs.h b/drivers/dma/dw_dmac_regs.h
index b119fd522927..cce1752d8f80 100644
--- a/drivers/dma/dw_dmac_regs.h
+++ b/drivers/dma/dw_dmac_regs.h
@@ -140,6 +140,7 @@ struct dw_dma_chan {
 	u8			mask;
 	u8			priority;
 	bool			paused;
+	bool			initialized;
 
 	spinlock_t		lock;