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authorChen-Yu Tsai <wens@csie.org>2014-11-07 12:15:47 +0800
committerVinod Koul <vinod.koul@intel.com>2014-11-17 13:50:37 +0530
commit0b04ddf8638ca5652b1f7ab7794beb363942407d (patch)
tree49e9e17006614ade242878406d396f475ef83870 /drivers/dma/sun6i-dma.c
parent25a37c2f12351ada1e42d0663480a182f4e301db (diff)
downloadlinux-0b04ddf8638ca5652b1f7ab7794beb363942407d.tar.bz2
dmaengine: sun6i: Add support for Allwinner A23 (sun8i) variant
The A23 SoC has the same dma engine as the A31 (sun6i), with a reduced amount of endpoints and physical channels. Add the proper config data and compatible string to support it. A slight difference in sun8i is an undocumented register needs to be toggled for dma to function. Signed-off-by: Chen-Yu Tsai <wens@csie.org> Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Diffstat (limited to 'drivers/dma/sun6i-dma.c')
-rw-r--r--drivers/dma/sun6i-dma.c27
1 files changed, 27 insertions, 0 deletions
diff --git a/drivers/dma/sun6i-dma.c b/drivers/dma/sun6i-dma.c
index 531abbf68a9d..f9f8f4d9915f 100644
--- a/drivers/dma/sun6i-dma.c
+++ b/drivers/dma/sun6i-dma.c
@@ -43,6 +43,12 @@
#define DMA_STAT 0x30
/*
+ * sun8i specific registers
+ */
+#define SUN8I_DMA_GATE 0x20
+#define SUN8I_DMA_GATE_ENABLE 0x4
+
+/*
* Channels specific registers
*/
#define DMA_CHAN_ENABLE 0x00
@@ -878,8 +884,20 @@ static struct sun6i_dma_config sun6i_a31_dma_cfg = {
.nr_max_vchans = 53,
};
+/*
+ * The A23 only has 8 physical channels, a maximum DRQ port id of 24,
+ * and a total of 37 usable source and destination endpoints.
+ */
+
+static struct sun6i_dma_config sun8i_a23_dma_cfg = {
+ .nr_max_channels = 8,
+ .nr_max_requests = 24,
+ .nr_max_vchans = 37,
+};
+
static struct of_device_id sun6i_dma_match[] = {
{ .compatible = "allwinner,sun6i-a31-dma", .data = &sun6i_a31_dma_cfg },
+ { .compatible = "allwinner,sun8i-a23-dma", .data = &sun8i_a23_dma_cfg },
{ /* sentinel */ }
};
@@ -1007,6 +1025,15 @@ static int sun6i_dma_probe(struct platform_device *pdev)
goto err_dma_unregister;
}
+ /*
+ * sun8i variant requires us to toggle a dma gating register,
+ * as seen in Allwinner's SDK. This register is not documented
+ * in the A23 user manual.
+ */
+ if (of_device_is_compatible(pdev->dev.of_node,
+ "allwinner,sun8i-a23-dma"))
+ writel(SUN8I_DMA_GATE_ENABLE, sdc->base + SUN8I_DMA_GATE);
+
return 0;
err_dma_unregister: