[PATCH v2 2/3] dmaengine: sun6i: Add support for Allwinner A23 (sun8i) variant
From: Chen-Yu Tsai <hidden>
Date: 2014-09-18 03:24:39
Also in:
linux-devicetree
Subsystem:
dma generic offload engine subsystem, open firmware and flattened device tree bindings, the rest · Maintainers:
Vinod Koul, Rob Herring, Krzysztof Kozlowski, Conor Dooley, Linus Torvalds
Possibly related (same subject, not in this thread)
- 2014-09-20 · Re: [PATCH v2 2/3] dmaengine: sun6i: Add support for Allwinner A23 (sun8i) variant · Maxime Ripard <hidden>
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 <redacted> --- .../devicetree/bindings/dma/sun6i-dma.txt | 2 +- drivers/dma/Kconfig | 4 ++-- drivers/dma/sun6i-dma.c | 27 ++++++++++++++++++++++ 3 files changed, 30 insertions(+), 3 deletions(-)
diff --git a/Documentation/devicetree/bindings/dma/sun6i-dma.txt b/Documentation/devicetree/bindings/dma/sun6i-dma.txt
index 3e145c1..9cdcba24d 100644
--- a/Documentation/devicetree/bindings/dma/sun6i-dma.txt
+++ b/Documentation/devicetree/bindings/dma/sun6i-dma.txt@@ -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
diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
index 9b1ea0e..5361aa7 100644
--- a/drivers/dma/Kconfig
+++ b/drivers/dma/Kconfig@@ -395,12 +395,12 @@ 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"
diff --git a/drivers/dma/sun6i-dma.c b/drivers/dma/sun6i-dma.c
index 89ca0c4..cb9aa43 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 */ } };
@@ -1008,6 +1026,15 @@ 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:
--
2.1.0