linux-kernel - [PATCH v2 05/15] dmaengine: dw: set LMS field in descriptors

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Date:	Mon, 22 Feb 2016 18:03:40 +0200
From:	Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To:	Viresh Kumar <vireshk@...nel.org>,
	Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
	Vinod Koul <vinod.koul@...el.com>,
	linux-kernel@...r.kernel.org, dmaengine@...r.kernel.org,
	Rob Herring <robh+dt@...nel.org>,
	Hans-Christian Egtvedt <egtvedt@...fundet.no>,
	Tejun Heo <tj@...nel.org>, Mark Brown <broonie@...nel.org>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Mark Rutland <mark.rutland@....com>,
	Vineet Gupta <vgupta@...opsys.com>
Cc:	Mans Rullgard <mans@...sr.com>
Subject: [PATCH v2 05/15] dmaengine: dw: set LMS field in descriptors

From: Mans Rullgard <mans@...sr.com>

The LMS field indicates from which master the descriptor is to be
read.  This patch assumes this is always the same as the memory
side in a peripheral transfer which is true for all known systems.

Signed-off-by: Mans Rullgard <mans@...sr.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
---
 drivers/dma/dw/core.c | 19 +++++++++----------
 drivers/dma/dw/regs.h |  4 ++++
 2 files changed, 13 insertions(+), 10 deletions(-)

diff --git a/drivers/dma/dw/core.c b/drivers/dma/dw/core.c
index 67e8618..90299fe 100644
--- a/drivers/dma/dw/core.c
+++ b/drivers/dma/dw/core.c
@@ -264,7 +264,7 @@ static void dwc_dostart(struct dw_dma_chan *dwc, struct dw_desc *first)
 
 	dwc_initialize(dwc);
 
-	channel_writel(dwc, LLP, first->txd.phys);
+	channel_writel(dwc, LLP, first->txd.phys | DWC_LLP_LMS(dwc->m_master));
 	channel_writel(dwc, CTL_LO,
 			DWC_CTLL_LLP_D_EN | DWC_CTLL_LLP_S_EN);
 	channel_writel(dwc, CTL_HI, 0);
@@ -430,7 +430,7 @@ static void dwc_scan_descriptors(struct dw_dma *dw, struct dw_dma_chan *dwc)
 		dwc->residue = desc->total_len;
 
 		/* Check first descriptors addr */
-		if (desc->txd.phys == llp) {
+		if (desc->txd.phys == DWC_LLP_LOC(llp)) {
 			spin_unlock_irqrestore(&dwc->lock, flags);
 			return;
 		}
@@ -755,7 +755,7 @@ dwc_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
 		if (!first) {
 			first = desc;
 		} else {
-			lli_write(prev, llp, desc->txd.phys);
+			lli_write(prev, llp, desc->txd.phys | DWC_LLP_LMS(dwc->m_master));
 			list_add_tail(&desc->desc_node, &first->tx_list);
 		}
 		prev = desc;
@@ -852,7 +852,7 @@ slave_sg_todev_fill_desc:
 			if (!first) {
 				first = desc;
 			} else {
-				lli_write(prev, llp, desc->txd.phys);
+				lli_write(prev, llp, desc->txd.phys | DWC_LLP_LMS(dwc->m_master));
 				list_add_tail(&desc->desc_node, &first->tx_list);
 			}
 			prev = desc;
@@ -907,7 +907,7 @@ slave_sg_fromdev_fill_desc:
 			if (!first) {
 				first = desc;
 			} else {
-				lli_write(prev, llp, desc->txd.phys);
+				lli_write(prev, llp, desc->txd.phys | DWC_LLP_LMS(dwc->m_master));
 				list_add_tail(&desc->desc_node, &first->tx_list);
 			}
 			prev = desc;
@@ -1432,13 +1432,13 @@ struct dw_cyclic_desc *dw_dma_cyclic_prep(struct dma_chan *chan,
 		cdesc->desc[i] = desc;
 
 		if (last)
-			lli_write(last, llp, desc->txd.phys);
+			lli_write(last, llp, desc->txd.phys | DWC_LLP_LMS(dwc->m_master));
 
 		last = desc;
 	}
 
 	/* Let's make a cyclic list */
-	lli_write(last, llp, cdesc->desc[0]->txd.phys);
+	lli_write(last, llp, cdesc->desc[0]->txd.phys | DWC_LLP_LMS(dwc->m_master));
 
 	dev_dbg(chan2dev(&dwc->chan),
 			"cyclic prepared buf %pad len %zu period %zu periods %d\n",
@@ -1640,9 +1640,8 @@ int dw_dma_probe(struct dw_dma_chip *chip, struct dw_dma_platform_data *pdata)
 			dwc->block_size = pdata->block_size;
 
 			/* Check if channel supports multi block transfer */
-			channel_writel(dwc, LLP, 0xfffffffc);
-			dwc->nollp =
-				(channel_readl(dwc, LLP) & 0xfffffffc) == 0;
+			channel_writel(dwc, LLP, DWC_LLP_LOC(0xffffffff));
+			dwc->nollp = DWC_LLP_LOC(channel_readl(dwc, LLP)) == 0;
 			channel_writel(dwc, LLP, 0);
 		}
 	}
diff --git a/drivers/dma/dw/regs.h b/drivers/dma/dw/regs.h
index 6571100..59d6cec 100644
--- a/drivers/dma/dw/regs.h
+++ b/drivers/dma/dw/regs.h
@@ -143,6 +143,10 @@ enum dw_dma_msize {
 	DW_DMA_MSIZE_256,
 };
 
+/* Bitfields in LLP */
+#define DWC_LLP_LMS(x)		((x) & 3)	/* list master select */
+#define DWC_LLP_LOC(x)		((x) & ~3)	/* next lli */
+
 /* Bitfields in CTL_LO */
 #define DWC_CTLL_INT_EN		(1 << 0)	/* irqs enabled? */
 #define DWC_CTLL_DST_WIDTH(n)	((n)<<1)	/* bytes per element */
-- 
2.7.0