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@amd.com>
---
v2:
 - Reorder entries ns16550_config to keep it sorted by device ID.
 - Rename PCI_VENDOR_ID_WCH to PCI_VENDOR_ID_WCHIC as WCH has multiple
   vendor ids.

 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..cf10a06a3d 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;
 };
 
@@ -861,6 +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 2S1P */
+    {
+        .vendor_id = PCI_VENDOR_ID_WCHIC,
+        .dev_id = 0x3250,
+        .param = param_wch_ch382
+    },
+    /* WCH CH382 2S */
+    {
+        .vendor_id = PCI_VENDOR_ID_WCHIC,
+        .dev_id = 0x3253,
+        .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..15e938225c 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_WCHIC              0x1c00
+
 #define PCI_VENDOR_ID_INTEL              0x8086
 
 #endif /* XEN_PCI_IDS_H */
-- 
2.53.0