@@ -171,19 +171,26 @@ pci_xr17c154_setup(struct exar8250 *priv, struct pci_dev *pcidev,
return default_setup(priv, pcidev, idx, offset, port);
}
-static void setup_gpio(u8 __iomem *p)
+static void setup_gpio(struct pci_dev *pcidev, u8 __iomem *p)
{
+ /*
+ * The Commtech adapters required the MPIOs to be driven low. The Exar
+ * devices will export them as GPIOs, so we pre-configure them safely
+ * as inputs.
+ */
+ u8 dir = pcidev->vendor == PCI_VENDOR_ID_EXAR ? 0xff : 0x00;
+
writeb(0x00, p + UART_EXAR_MPIOINT_7_0);
writeb(0x00, p + UART_EXAR_MPIOLVL_7_0);
writeb(0x00, p + UART_EXAR_MPIO3T_7_0);
writeb(0x00, p + UART_EXAR_MPIOINV_7_0);
- writeb(0xff, p + UART_EXAR_MPIOSEL_7_0);
+ writeb(dir, p + UART_EXAR_MPIOSEL_7_0);
writeb(0x00, p + UART_EXAR_MPIOOD_7_0);
writeb(0x00, p + UART_EXAR_MPIOINT_15_8);
writeb(0x00, p + UART_EXAR_MPIOLVL_15_8);
writeb(0x00, p + UART_EXAR_MPIO3T_15_8);
writeb(0x00, p + UART_EXAR_MPIOINV_15_8);
- writeb(0xff, p + UART_EXAR_MPIOSEL_15_8);
+ writeb(dir, p + UART_EXAR_MPIOSEL_15_8);
writeb(0x00, p + UART_EXAR_MPIOOD_15_8);
}
@@ -236,7 +243,7 @@ pci_xr17v35x_setup(struct exar8250 *priv, struct pci_dev *pcidev,
if (idx == 0) {
/* Setup Multipurpose Input/Output pins. */
- setup_gpio(p);
+ setup_gpio(pcidev, p);
port->port.private_data = xr17v35x_register_gpio(pcidev);
}
Commtech adapters apparently need the original setting as outputs, see https://marc.info/?l=linux-gpio&m=149557425201323&w=2. Account for that. Fixes: 7dea8165f1d6 ("serial: exar: Preconfigure xr17v35x MPIOs as output") Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> --- drivers/tty/serial/8250/8250_exar.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-)