openkylin
/
linux
mirror of https://gitee.com/openkylin/linux.git
9
0
Fork 0
Code Issues Projects Releases Wiki Activity

serial: exar: Leave MPIOs as output for Commtech adapters 

Commtech adapters apparently need the original setting as outputs, see
https://marc.info/?l=linux-gpio&m=149557425201323&w=2. Account for that.

Fixes: 7dea8165f1 ("serial: exar: Preconfigure xr17v35x MPIOs as output")
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Jan Kiszka 2017-06-02 09:28:44 +02:00 committed by Greg Kroah-Hartman
parent 72ce5732ee
commit bea8be6561
1 changed files with 11 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

15
drivers/tty/serial/8250/8250_exar.c
View File

@ -170,19 +170,26 @@ 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);
}
@ -235,7 +242,7 @@ 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);
}