QCOM ADM DMA Controller
Required properties:
- compatible: must contain “qcom,adm” for IPQ/APQ8064 and MSM8960
- reg: Address range for DMA registers
- interrupts: Should contain one interrupt shared by all channels
- #dma-cells: must be <2>. First cell denotes the channel number. Second cell
denotes CRCI (client rate control interface) flow control assignment. - clocks: Should contain the core clock and interface clock.
- clock-names: Must contain “core” for the core clock and “iface” for the
interface clock. - resets: Must contain an entry for each entry in reset names.
- reset-names: Must include the following entries:
- clk
- c0
- c1
- c2
- qcom,ee: indicates the security domain identifier used in the secure world.
Example:
adm_dma: dma@18300000 {
compatible = “qcom,adm”;
reg = <0x18300000 0x100000>;
interrupts = <0 170 0>;
#dma-cells = <2>;
clocks = <&gcc ADM0_CLK>, <&gcc ADM0_PBUS_CLK>;
clock-names = "core", "iface";
resets = <&gcc ADM0_RESET>,
<&gcc ADM0_C0_RESET>,
<&gcc ADM0_C1_RESET>,
<&gcc ADM0_C2_RESET>;
reset-names = "clk", "c0", "c1", "c2";
qcom,ee = <0>;
};
DMA clients must use the format descripted in the dma.txt file, using a three
cell specifier for each channel.
Each dmas request consists of 3 cells:
- phandle pointing to the DMA controller
- channel number
- CRCI assignment, if applicable. If no CRCI flow control is required, use 0.
The CRCI is used for flow control. It identifies the peripheral device that
is the source/destination for the transferred data.
Example:
spi4: spi@1a280000 {
spi-max-frequency = <50000000>;
pinctrl-0 = <&spi_pins>;
pinctrl-names = "default";
cs-gpios = <&qcom_pinmux 20 0>;
dmas = <&adm_dma 6 9>,
<&adm_dma 5 10>;
dma-names = "rx", "tx";
};