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| author | Rong Zhang <rongrong@oss.cipunited.com> | 2026-03-15 21:44:00 +0300 |
|---|---|---|
| committer | Thomas Bogendoerfer <tsbogend@alpha.franken.de> | 2026-04-06 15:14:24 +0300 |
| commit | 79b888ee4c6387bc07c5452bfd031cb985871a5f (patch) | |
| tree | 1ab89917a235b789d60d4786f0a845b471b266c8 | |
| parent | 2300d68e577909c7d3013910ff818e8572288491 (diff) | |
| download | linux-79b888ee4c6387bc07c5452bfd031cb985871a5f.tar.xz | |
MIPS: dts: loongson64g-package: Switch to Loongson UART driver
Loongson64g is Loongson 3A4000, whose UART controller is compatible with
Loongson 2K1500, which is NS16550A-compatible with an additional
fractional frequency divisor register.
Update the compatible strings to reflect this, so that 3A4000 can
benefit from the fractional frequency divisor provided by loongson-uart.
This is required on some devices, otherwise their UART can't work at
some high baud rates, e.g., 115200.
Tested on Loongson-LS3A4000-7A1000-NUC-SE with a 25MHz UART clock.
Without fractional frequency divisor, the actual baud rate was 111607
(25MHz / 16 / 14, measured value: 111545) and some USB-to-UART
converters couldn't work with it at all. With fractional frequency
divisor, the measured baud rate becomes 115207, which is quite accurate.
Signed-off-by: Rong Zhang <rongrong@oss.cipunited.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
| -rw-r--r-- | arch/mips/boot/dts/loongson/loongson64g-package.dtsi | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/mips/boot/dts/loongson/loongson64g-package.dtsi b/arch/mips/boot/dts/loongson/loongson64g-package.dtsi index d4314f62ccc2..029daeedd0ab 100644 --- a/arch/mips/boot/dts/loongson/loongson64g-package.dtsi +++ b/arch/mips/boot/dts/loongson/loongson64g-package.dtsi @@ -40,7 +40,7 @@ }; cpu_uart0: serial@1fe00100 { - compatible = "ns16550a"; + compatible = "loongson,ls3a4000-uart", "loongson,ls2k1500-uart", "ns16550a"; reg = <0 0x1fe00100 0x10>; clock-frequency = <100000000>; interrupt-parent = <&liointc>; @@ -50,7 +50,7 @@ cpu_uart1: serial@1fe00110 { status = "disabled"; - compatible = "ns16550a"; + compatible = "loongson,ls3a4000-uart", "loongson,ls2k1500-uart", "ns16550a"; reg = <0 0x1fe00110 0x10>; clock-frequency = <100000000>; interrupts = <15 IRQ_TYPE_LEVEL_HIGH>; |