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dmaengine: sun6i: Add support for Allwinner A23 (sun8i) variant

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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>
This commit is contained in:
Chen-Yu Tsai 2014-11-07 12:15:47 +08:00 committed by Vinod Koul
parent 25a37c2f12
commit 0b04ddf863
3 changed files with 30 additions and 3 deletions
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2
Documentation/devicetree/bindings/dma/sun6i-dma.txt
View File

@ -4,7 +4,7 @@ This driver follows the generic DMA bindings defined in dma.txt.
Required properties:
- compatible: Must be "allwinner,sun6i-a31-dma"
- compatible: Must be "allwinner,sun6i-a31-dma" or "allwinner,sun8i-a23-dma"
- reg: Should contain the registers base address and length
- interrupts: Should contain a reference to the interrupt used by this device
- clocks: Should contain a reference to the parent AHB clock

4
drivers/dma/Kconfig
View File

@ -402,12 +402,12 @@ config XILINX_VDMA
config DMA_SUN6I
tristate "Allwinner A31 SoCs DMA support"
depends on MACH_SUN6I || COMPILE_TEST
depends on MACH_SUN6I || MACH_SUN8I || COMPILE_TEST
depends on RESET_CONTROLLER
select DMA_ENGINE
select DMA_VIRTUAL_CHANNELS
help
Support for the DMA engine for Allwinner A31 SoCs.
Support for the DMA engine first found in Allwinner A31 SoCs.
config NBPFAXI_DMA
tristate "Renesas Type-AXI NBPF DMA support"

27
drivers/dma/sun6i-dma.c
View File

@ -42,6 +42,12 @@
#define DMA_STAT 0x30
/*
* sun8i specific registers
*/
#define SUN8I_DMA_GATE 0x20
#define SUN8I_DMA_GATE_ENABLE 0x4
/*
* Channels specific registers
*/
@ -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: