diff options
Diffstat (limited to 'Documentation/devicetree/bindings/serial/qcom,msm-uartdm.txt')
-rw-r--r-- | Documentation/devicetree/bindings/serial/qcom,msm-uartdm.txt | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/serial/qcom,msm-uartdm.txt b/Documentation/devicetree/bindings/serial/qcom,msm-uartdm.txt new file mode 100644 index 000000000..9d098cf73 --- /dev/null +++ b/Documentation/devicetree/bindings/serial/qcom,msm-uartdm.txt @@ -0,0 +1,81 @@ +* MSM Serial UARTDM + +The MSM serial UARTDM hardware is designed for high-speed use cases where the +transmit and/or receive channels can be offloaded to a dma-engine. From a +software perspective it's mostly compatible with the MSM serial UART except +that it supports reading and writing multiple characters at a time. + +Required properties: +- compatible: Should contain at least "qcom,msm-uartdm". + A more specific property should be specified as follows depending + on the version: + "qcom,msm-uartdm-v1.1" + "qcom,msm-uartdm-v1.2" + "qcom,msm-uartdm-v1.3" + "qcom,msm-uartdm-v1.4" +- reg: Should contain UART register locations and lengths. The first + register shall specify the main control registers. An optional second + register location shall specify the GSBI control region. + "qcom,msm-uartdm-v1.3" is the only compatible value that might + need the GSBI control region. +- interrupts: Should contain UART interrupt. +- clocks: Should contain the core clock and the AHB clock. +- clock-names: Should be "core" for the core clock and "iface" for the + AHB clock. + +Optional properties: +- dmas: Should contain dma specifiers for transmit and receive channels +- dma-names: Should contain "tx" for transmit and "rx" for receive channels +- qcom,tx-crci: Identificator <u32> for Client Rate Control Interface to be + used with TX DMA channel. Required when using DMA for transmission + with UARTDM v1.3 and below. +- qcom,rx-crci: Identificator <u32> for Client Rate Control Interface to be + used with RX DMA channel. Required when using DMA for reception + with UARTDM v1.3 and below. + +Note: Aliases may be defined to ensure the correct ordering of the UARTs. +The alias serialN will result in the UART being assigned port N. If any +serialN alias exists, then an alias must exist for each enabled UART. The +serialN aliases should be in a .dts file instead of in a .dtsi file. + +Examples: + +- A uartdm v1.4 device with dma capabilities. + + serial@f991e000 { + compatible = "qcom,msm-uartdm-v1.4", "qcom,msm-uartdm"; + reg = <0xf991e000 0x1000>; + interrupts = <0 108 0x0>; + clocks = <&blsp1_uart2_apps_cxc>, <&blsp1_ahb_cxc>; + clock-names = "core", "iface"; + dmas = <&dma0 0>, <&dma0 1>; + dma-names = "tx", "rx"; + }; + +- A uartdm v1.3 device without dma capabilities and part of a GSBI complex. + + serial@19c40000 { + compatible = "qcom,msm-uartdm-v1.3", "qcom,msm-uartdm"; + reg = <0x19c40000 0x1000>, + <0x19c00000 0x1000>; + interrupts = <0 195 0x0>; + clocks = <&gsbi5_uart_cxc>, <&gsbi5_ahb_cxc>; + clock-names = "core", "iface"; + }; + +- serialN alias. + + aliases { + serial0 = &uarta; + serial1 = &uartc; + serial2 = &uartb; + }; + + uarta: serial@12490000 { + }; + + uartb: serial@16340000 { + }; + + uartc: serial@1a240000 { + }; |