kernel/Documentation/devicetree/bindings/serial/8250.yaml, branch linux-rolling-stable

dt-bindings: serial: 8250: Add Loongson uart compatible

2025-11-26T12:14:24Z

The Loongson family have a mostly NS16550A-compatible UART and High-Speed UART hardware with the exception of custom frequency divider latch settings register. Co-developed-by: Haowei Zheng Signed-off-by: Haowei Zheng Acked-by: Conor Dooley Signed-off-by: Binbin Zhou Reviewed-by: Huacai Chen Link: https://patch.msgid.link/2d858e9303d95a3e4909aa9c1379d4abbdc52cc2.1760166651.git.zhoubinbin@loongson.cn Signed-off-by: Greg Kroah-Hartman

dt-bindings: serial: 8250: allow "main" and "uart" as clock names

2025-08-14T10:12:31Z

There are two compatible strings defined in "8250.yaml" that require two clocks to be specified, along with their names: - "spacemit,k1-uart", used in "spacemit/k1.dtsi" - "nxp,lpc1850-uart", used in "lpc/lpc18xx.dtsi" When only one clock is used, the name is not required. However there are two places that do specify a name: - In "mediatek/mt7623.dtsi", the clock for the "mediatek,mtk-btif" compatible serial device is named "main" - In "qca/ar9132.dtsi", the clock for the "ns8250" compatible serial device is named "uart" In commit d2db0d7815444 ("dt-bindings: serial: 8250: allow clock 'uartclk' and 'reg' for nxp,lpc1850-uart"), Frank Li added the restriction that two named clocks be used for the NXP platform mentioned above. Change that logic, so that an additional condition for (only) the SpacemiT platform similarly restricts the two clocks to have the names "core" and "bus". Finally, add "main" and "uart" as allowed names when a single clock is specified. Fixes: 2c0594f9f0629 ("dt-bindings: serial: 8250: support an optional second clock") Cc: stable Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202507160314.wrC51lXX-lkp@intel.com/ Signed-off-by: Alex Elder Acked-by: Conor Dooley Link: https://lore.kernel.org/r/20250813031338.2328392-1-elder@riscstar.com Signed-off-by: Greg Kroah-Hartman

dt-bindings: serial: 8250: move a constraint

2025-08-14T10:12:18Z

A block that required a "spacemit,k1-uart" compatible node to specify two clocks was placed in the wrong spot in the binding. Conor Dooley pointed out it belongs earlier in the file, as part of the initial "allOf". Fixes: 2c0594f9f0629 ("dt-bindings: serial: 8250: support an optional second clock") Cc: stable Reported-by: Conor Dooley Closes: https://lore.kernel.org/lkml/20250729-reshuffle-contented-e6def76b540b@spud/ Signed-off-by: Alex Elder Acked-by: Conor Dooley Link: https://lore.kernel.org/r/20250813032151.2330616-1-elder@riscstar.com Signed-off-by: Greg Kroah-Hartman

dt-bindings: serial: 8250: spacemit: set clocks property as required

2025-07-21T15:38:54Z

In SpacemiT's K1 SoC, the clocks for UART are mandatory needed, so for DT, both clocks and clock-names property should be set as required. Fixes: 2c0594f9f062 ("dt-bindings: serial: 8250: support an optional second clock") Signed-off-by: Yixun Lan Acked-by: "Rob Herring (Arm)" Link: https://lore.kernel.org/r/20250718-01-k1-uart-binding-v1-1-a92e1e14c836@gentoo.org Signed-off-by: Greg Kroah-Hartman

Merge 6.16-rc4 into tty-next

2025-06-30T05:50:04Z

We need the tty/serial fixes in here as well. Signed-off-by: Greg Kroah-Hartman

dt-bindings: serial: 8250: allow clock 'uartclk' and 'reg' for nxp,lpc1850-uart

2025-06-29T12:19:27Z

Allow clock 'uartclk' and 'reg' for nxp,lpc1850-uart to align existed driver and dts. It is really old platform. Keep the same restriction for others. Allow dmas and dma-names property, which allow maxItems 4 because very old platform (arch/arm/boot/dts/nxp/lpc/lpc18xx.dtsi) use duplicate "tx", "rx", "tx", "rx" as dma-names. Fix below CHECK_DTB warnings: arch/arm/boot/dts/nxp/lpc/lpc4337-ciaa.dtb: serial@40081000 (nxp,lpc1850-uart): clock-names: ['uartclk', 'reg'] is too long Signed-off-by: Frank Li Acked-by: "Rob Herring (Arm)" Link: https://lore.kernel.org/r/20250602142745.942568-1-Frank.Li@nxp.com Signed-off-by: Greg Kroah-Hartman

dt-bindings: serial: 8250: Make clocks and clock-frequency exclusive

2025-06-24T14:34:37Z

The 8250 binding before converting to json-schema states, - clock-frequency : the input clock frequency for the UART or - clocks phandle to refer to the clk used as per Documentation/devicetree for clock-related properties, where "or" indicates these properties shouldn't exist at the same time. Additionally, the behavior of Linux's driver is strange when both clocks and clock-frequency are specified: it ignores clocks and obtains the frequency from clock-frequency, left the specified clocks unclaimed. It may even be disabled, which is undesired most of the time. But "anyOf" doesn't prevent these two properties from coexisting, as it considers the object valid as long as there's at LEAST one match. Let's switch to "oneOf" and disallows the other property if one exists, precisely matching the original binding and avoiding future confusion on the driver's behavior. Fixes: e69f5dc623f9 ("dt-bindings: serial: Convert 8250 to json-schema") Cc: stable Signed-off-by: Yao Zi Reviewed-by: Conor Dooley Link: https://lore.kernel.org/r/20250623093445.62327-1-ziyao@disroot.org Signed-off-by: Greg Kroah-Hartman

dt-bindings: serial: 8250: support an optional second clock

2025-04-11T14:52:47Z

The SpacemiT UART driver requires a bus clock to be enabled in addition to the primary function clock. Add the option to specify two clocks for an 8250-compatible UART, named "core" and "bus". If both are needed, require them to be named. Signed-off-by: Alex Elder Reviewed-by: Rob Herring (Arm) Link: https://lore.kernel.org/r/20250409192213.1130181-2-elder@riscstar.com Signed-off-by: Greg Kroah-Hartman

dt-bindings: serial: Allow fsl,ns16550 with broken FIFOs

2025-02-14T09:05:21Z

While testing on a Freescale MPC8314E board, I noticed that changing the UART compatible string from ns16550 to ns16550a breaks the output, suggesting that the FIFOs don't work correctly. To accommodate this fact, move the definition of fsl,ns16550 to the section of 8250.yaml that allows broken FIFOs. Signed-off-by: J. Neuschäfer Acked-by: Conor Dooley Link: https://lore.kernel.org/r/20250209-uartfifo-v1-1-501a510a5f07@posteo.net Signed-off-by: Greg Kroah-Hartman

Revert "dt-bindings: serial: 8250: Add Airoha compatibles"

2025-02-06T05:16:32Z

This reverts commit ed333392bd201e71a010e588e61605a1e2dd07df. It was part of a patch series that caused build errors in linux-next. Cc: Benjamin Larsson Reported-by: Stephen Rothwell Link: https://lore.kernel.org/r/20250206135328.4bad1401@canb.auug.org.au Signed-off-by: Greg Kroah-Hartman