Re: [PATCH] ns16550: add support for WCH CH382 serial adapters

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

On Fri, 8 May 2026, Jiaqing Zhao wrote:
> Add support for the WCH (Nanjing Qinheng Microelectronics Co., Ltd.)
> CH382 PCIe dual port serial adapter. The CH382 is available in two
> variants:
>  - CH382 2S   [1c00:3253]: 2 serial ports
>  - CH382 2S1P [1c00:3250]: 2 serial ports + 1 parallel port
> 
> This chip uses IO BAR0, base baud rate 115200, ports starting at offset
> 0xc0 and spaced 8 bytes apart, and a 256-byte FIFO. [1]
> 
> [1] https://www.wch-ic.com/downloads/CH382DS1_PDF.html
> 
> Signed-off-by: Jiaqing Zhao <Zhao.Jiaqing@xxxxxxx>

WCH has a few PCI vendor IDs, including 0x1c00 and also 0x4348. Linux
distinguishes them as PCI_VENDOR_ID_WCHIC = 0x1c00 and
PCI_VENDOR_ID_WCHCN = 0x4348. It would probably be better to rename
PCI_VENDOR_ID_WCH to PCI_VENDOR_ID_WCHIC in this patch.

Everything else looks good.

> ---
>  xen/drivers/char/ns16550.c | 23 +++++++++++++++++++++++
>  xen/include/xen/pci_ids.h  |  2 ++
>  2 files changed, 25 insertions(+)
> 
> diff --git a/xen/drivers/char/ns16550.c b/xen/drivers/char/ns16550.c
> index 878da27f2e..106ef56316 100644
> --- a/xen/drivers/char/ns16550.c
> +++ b/xen/drivers/char/ns16550.c
> @@ -95,6 +95,7 @@ struct ns16550_config {
>          param_exar_xr17v354,
>          param_exar_xr17v358,
>          param_intel_lpss,
> +        param_wch_ch382,
>      } param;
>  };
  
> @@ -862,6 +862,16 @@ static const struct ns16550_config_param __initconst 
> uart_param[] = {
>          .mmio = 1,
>          .max_ports = 1,
>      },
> +    [param_wch_ch382] = {
> +        .base_baud = 115200,
> +        .first_offset = 0xc0,
> +        .uart_offset = 8,
> +        .reg_width = 1,
> +        .fifo_size = 256,
> +        .lsr_mask = UART_LSR_THRE,
> +        .bar0 = 1,
> +        .max_ports = 2,
> +    },
>  };
>  
>  static const struct ns16550_config __initconst uart_config[] =
> @@ -1189,6 +1200,18 @@ static const struct ns16550_config __initconst 
> uart_config[] =
>          .dev_id = 0x7adc,
>          .param = param_intel_lpss
>      },
> +    /* WCH CH382 2S */
> +    {
> +        .vendor_id = PCI_VENDOR_ID_WCH,
> +        .dev_id = 0x3253,
> +        .param = param_wch_ch382
> +    },
> +    /* WCH CH382 2S1P */
> +    {
> +        .vendor_id = PCI_VENDOR_ID_WCH,
> +        .dev_id = 0x3250,
> +        .param = param_wch_ch382
> +    },
>  };
>  
>  static int __init
> diff --git a/xen/include/xen/pci_ids.h b/xen/include/xen/pci_ids.h
> index 5884a20b8f..b8316d464c 100644
> --- a/xen/include/xen/pci_ids.h
> +++ b/xen/include/xen/pci_ids.h
> @@ -13,6 +13,8 @@
>  
>  #define PCI_VENDOR_ID_BROADCOM           0x14e4
>  
> +#define PCI_VENDOR_ID_WCH                0x1c00
> +
>  #define PCI_VENDOR_ID_INTEL              0x8086
>  
>  #endif /* XEN_PCI_IDS_H */
> -- 
> 2.53.0
>