[15/15] dmaengine: dw-axi-dmac: Set constraint to the Max segment size
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Message ID 20201012042200.29787-16-jee.heng.sia@intel.com
State New, archived
Headers show
Series
  • dmaengine: dw-axi-dmac: support Intel KeemBay AxiDMA
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Commit Message

Sia Jee Heng Oct. 12, 2020, 4:22 a.m. UTC
Add support for DMA Scatter-Gather (SG) constraint so that DMA clients can
handle the AxiDMA limitation.

Without supporting DMA constraint the default Max segment size reported by
dmaengine is 64KB, which is not supported by Intel KeemBay AxiDMA.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Sia Jee Heng <jee.heng.sia@intel.com>
---
 drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c | 8 ++++++++
 drivers/dma/dw-axi-dmac/dw-axi-dmac.h          | 1 +
 2 files changed, 9 insertions(+)

Patch
diff mbox series

diff --git a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
index d4fca3ffe67f..bd56e21663c3 100644
--- a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
+++ b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
@@ -12,6 +12,7 @@ 
 #include <linux/device.h>
 #include <linux/dmaengine.h>
 #include <linux/dmapool.h>
+#include <linux/dma-mapping.h>
 #include <linux/err.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
@@ -1407,6 +1408,13 @@  static int dw_probe(struct platform_device *pdev)
 	dw->dma.device_prep_slave_sg = dw_axi_dma_chan_prep_slave_sg;
 	dw->dma.device_prep_dma_cyclic = dw_axi_dma_chan_prep_cyclic;
 
+	/*
+	 * Synopsis DesignWare AxiDMA datasheet mentioned Maximum
+	 * supported blocks is 1024. Device register width is 4 bytes.
+	 * Therefore, set constraint to 1024 * 4.
+	 */
+	dw->dma.dev->dma_parms = &dw->dma_parms;
+	dma_set_max_seg_size(&pdev->dev, MAX_BLOCK_SIZE);
 	platform_set_drvdata(pdev, chip);
 
 	pm_runtime_enable(chip->dev);
diff --git a/drivers/dma/dw-axi-dmac/dw-axi-dmac.h b/drivers/dma/dw-axi-dmac/dw-axi-dmac.h
index f64e8d33b127..67669049cead 100644
--- a/drivers/dma/dw-axi-dmac/dw-axi-dmac.h
+++ b/drivers/dma/dw-axi-dmac/dw-axi-dmac.h
@@ -54,6 +54,7 @@  struct axi_dma_chan {
 struct dw_axi_dma {
 	struct dma_device	dma;
 	struct dw_axi_dma_hcfg	*hdata;
+	struct device_dma_parameters	dma_parms;
 
 	/* channels */
 	struct axi_dma_chan	*chan;