Normally, the number of ports is indicated by the third digit of the
device ID on Moxa PCI serial boards. For example, `0x1121` indicates a
device with 2 ports.
However, `CP116E_A_A` and `CP116E_A_B` are exceptions; they have 8
ports, but the third digit of the device ID is `6`.
This patch introduces a function to retrieve the number of ports on Moxa
PCI serial boards, addressing the issue described above.
Fixes: 37058fd5d239 ("tty: serial: 8250: Add support for MOXA Mini PCIe boards")
Signed-off-by: Crescent Hsieh <crescentcy.hsieh@xxxxxxxx>
---
Changes from v1 to v2:
- Add the "Fixes" tag correctly
v1: https://lore.kernel.org/all/20240614090322.2303-1-crescentcy.hsieh@xxxxxxxx/
---
drivers/tty/serial/8250/8250_pci.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/drivers/tty/serial/8250/8250_pci.c b/drivers/tty/serial/8250/8250_pci.c
index 40af74b55933..e1d7aa2fa347 100644
--- a/drivers/tty/serial/8250/8250_pci.c
+++ b/drivers/tty/serial/8250/8250_pci.c
@@ -1985,6 +1985,17 @@ enum {
MOXA_SUPP_RS485 = BIT(2),
};
+static unsigned short moxa_get_nports(unsigned short device)
+{
+ switch (device) {
+ case PCI_DEVICE_ID_MOXA_CP116E_A_A:
+ case PCI_DEVICE_ID_MOXA_CP116E_A_B:
+ return 8;
+ }
+
+ return FIELD_GET(0x00F0, device);
+}
+
static bool pci_moxa_is_mini_pcie(unsigned short device)
{
if (device == PCI_DEVICE_ID_MOXA_CP102N ||
@@ -2038,7 +2049,7 @@ static int pci_moxa_init(struct pci_dev *dev)
{
unsigned short device = dev->device;
resource_size_t iobar_addr = pci_resource_start(dev, 2);
- unsigned int num_ports = (device & 0x00F0) >> 4, i;
+ unsigned int i, num_ports = moxa_get_nports(device);
u8 val, init_mode = MOXA_RS232;
if (!(pci_moxa_supported_rs(dev) & MOXA_SUPP_RS232)) {
--
2.34.1
