[v12,16/17] dmaengine: dw-axi-dmac: Set constraint to the Max segment size
diff mbox series

Message ID 20210125013255.25799-17-jee.heng.sia@intel.com
State Accepted
Commit 78a90a1e489e3f19b0adf8327f432ee0684a7680
Headers show
Series
  • dmaengine: dw-axi-dmac: support Intel KeemBay AxiDMA
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Commit Message

Sia, Jee Heng Jan. 25, 2021, 1:32 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.

Signed-off-by: Sia Jee Heng <jee.heng.sia@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Tested-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.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 a1dddec95316..88d4923dee6c 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>
@@ -1340,6 +1341,13 @@  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 3a357f7fda02..1e937ea2a96d 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;