From 0dd1e247fd39aed20fd2baacc62ca44d82534798 Mon Sep 17 00:00:00 2001 From: Andre Przywara Date: Thu, 21 May 2015 17:26:23 +0100 Subject: drivers: PL011: add support for the ARM SBSA generic UART The ARM Server Base System Architecture[1] document describes a generic UART which is a subset of the PL011 UART. It lacks DMA support, baud rate control and modem status line control, among other things. The idea is to move the UART initialization and setup into the firmware (which does this job today already) and let the kernel just use the UART for sending and receiving characters. We use the recent refactoring to build a new struct uart_ops variable which points to some new functions avoiding access to the missing registers. We reuse as much existing PL011 code as possible. In contrast to the PL011 the SBSA UART does not define any AMBA or PrimeCell relations, so we go with a pretty generic probe function which only uses platform device functions. A DT binding is provided with this patch, ACPI support is added in a separate one. Signed-off-by: Andre Przywara Tested-by: Mark Langsdorf Tested-by: Naresh Bhat Signed-off-by: Greg Kroah-Hartman --- Documentation/devicetree/bindings/serial/arm_sbsa_uart.txt | 10 ++++++++++ 1 file changed, 10 insertions(+) create mode 100644 Documentation/devicetree/bindings/serial/arm_sbsa_uart.txt (limited to 'Documentation/devicetree') diff --git a/Documentation/devicetree/bindings/serial/arm_sbsa_uart.txt b/Documentation/devicetree/bindings/serial/arm_sbsa_uart.txt new file mode 100644 index 0000000..4163e7e --- /dev/null +++ b/Documentation/devicetree/bindings/serial/arm_sbsa_uart.txt @@ -0,0 +1,10 @@ +* ARM SBSA defined generic UART +This UART uses a subset of the PL011 registers and consequently lives +in the PL011 driver. It's baudrate and other communication parameters +cannot be adjusted at runtime, so it lacks a clock specifier here. + +Required properties: +- compatible: must be "arm,sbsa-uart" +- reg: exactly one register range +- interrupts: exactly one interrupt specifier +- current-speed: the (fixed) baud rate set by the firmware -- cgit v1.1