Staging
v0.7.0
v0.7.0
https://github.com/torvalds/linux
Tip revision: bfeffd155283772bbe78c6a05dec7c0128ee500c authored by Linus Torvalds on 07 January 2019, 01:08:20 UTC
Linux 5.0-rc1
Linux 5.0-rc1
Tip revision: bfeffd1
qcom,msm-uartdm.txt
* 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 {
};