diff options
| author | Jan Kiszka <jan.kiszka@siemens.com> | 2017-06-02 10:28:44 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-06-09 12:23:36 +0300 |
| commit | bea8be656185a2808a2f255f4a91ff18215a9d0c (patch) | |
| tree | eb4542783461d63392c76429e44f3b0770685098 /drivers/tty/serial | |
| parent | 72ce5732eeca023abb04e40eb77a6bc1169d9b9d (diff) | |
| download | linux-bea8be656185a2808a2f255f4a91ff18215a9d0c.tar.xz | |
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: 7dea8165f1d6 ("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>
Diffstat (limited to 'drivers/tty/serial')
| -rw-r--r-- | drivers/tty/serial/8250/8250_exar.c | 15 |
1 files changed, 11 insertions, 4 deletions
diff --git a/drivers/tty/serial/8250/8250_exar.c b/drivers/tty/serial/8250/8250_exar.c index 0a20f7185094..a309bcffffcd 100644 --- a/drivers/tty/serial/8250/8250_exar.c +++ b/drivers/tty/serial/8250/8250_exar.c @@ -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); } |