Messages in this thread Patch in this message | | | Date | Thu, 19 Oct 2023 08:24:52 +0200 | Subject | Re: [PATCH v3 6/6] tty: serial: 8250: Add support for MOXA PCIe boards to switch interface between RS422/RS485 | From | Jiri Slaby <> |
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On 18. 10. 23, 11:17, Crescent CY Hsieh wrote: > MOXA PCIe boards have 4 serial interfaces and don't require additional > stuff to switch between interfaces: > > - RS232 > - RS422 > - RS485_2W (half-duplex) > - RS485_4W (full-duplex) > > By using ioctl command "TIOCRS485", it can switch between default > interface and RS485 if supported. > > That means, for RS422/RS485 board, it can switch between RS422 and > RS485 by setting the flags within struct serial_rs485. > > However, for the RS232/RS422/RS485 board, it can only switch between > RS232 and RS485, there's no flag for switching interface into RS422. > > This patch uses "SER_RS485_TERMINATE_BUS" to represent RS422 as a > workaround solution: > > - RS232 = (no flags are set) > - RS422 = SER_RS485_ENABLED | SER_RS485_TERMINATE_BUS > - RS485_2W (half-duplex) = SER_RS485_ENABLED > - RS485_4W (full-duplex) = SER_RS485_ENABLED | SER_RS485_RX_DURING_TX > > Signed-off-by: Crescent CY Hsieh <crescentcy.hsieh@moxa.com> > --- > drivers/tty/serial/8250/8250_pci.c | 58 ++++++++++++++++++++++++++++++ > 1 file changed, 58 insertions(+) > > diff --git a/drivers/tty/serial/8250/8250_pci.c b/drivers/tty/serial/8250/8250_pci.c > index 29a28e72b..098ac466b 100644 > --- a/drivers/tty/serial/8250/8250_pci.c > +++ b/drivers/tty/serial/8250/8250_pci.c > @@ -1974,6 +1974,10 @@ pci_sunix_setup(struct serial_private *priv, > #define MOXA_RS485_2W 0x0F > #define MOXA_UIR_OFFSET 0x04 > > +static const struct serial_rs485 pci_moxa_rs485_supported = { > + .flags = SER_RS485_ENABLED | SER_RS485_RX_DURING_TX | SER_RS485_TERMINATE_BUS, > +}; > + > static bool pci_moxa_is_mini_pcie(unsigned short device) > { > if (device == PCI_DEVICE_ID_MOXA_CP102N || > @@ -2024,6 +2028,46 @@ static int pci_moxa_set_interface(const struct pci_dev *dev, > return 0; > } > > +/* > + * MOXA PCIe boards support switching the serial interface using the ioctl > + * command "TIOCSRS485", but there is currently no dedicated flag for switching > + * to RS422. As a workaround, we utilize the "SER_RS485_TERMINATE_BUS" flag to > + * represent RS422. > + * > + * RS232 = (no flags are set) > + * RS422 = SER_RS485_ENABLED | SER_RS485_TERMINATE_BUS > + * RS485_2W (half-duplex) = SER_RS485_ENABLED > + * RS485_4W (full-duplex) = SER_RS485_ENABLED | SER_RS485_RX_DURING_TX > + */ > +static int pci_moxa_rs485_config(struct uart_port *port, > + struct ktermios *termios, > + struct serial_rs485 *rs485) > +{ > + struct pci_dev *dev = to_pci_dev(port->dev); > + unsigned short device = dev->device; > + u8 mode = MOXA_RS232; > + > + if (rs485->flags & SER_RS485_ENABLED) { > + if (rs485->flags & SER_RS485_TERMINATE_BUS) { > + mode = MOXA_RS422; > + } else { > + if (rs485->flags & SER_RS485_RX_DURING_TX) > + mode = MOXA_RS485_4W; > + else > + mode = MOXA_RS485_2W; > + } > + } else { > + /* > + * RS232 is not supported for MOXA PCIe boards with device IDs > + * matching the pattern 0x*3**. > + */ > + if (pci_moxa_match_second_digit(device, 0x0300))
The same here: if (!(pci_moxa_supported_rs(dev) & MOXA_SUPP_RS232))
> + return -EOPNOTSUPP; > + } > + > + return pci_moxa_set_interface(dev, port->port_id, mode); > +} > + > static int pci_moxa_init(struct pci_dev *dev) > { > unsigned short device = dev->device; > @@ -2063,9 +2107,23 @@ pci_moxa_setup(struct serial_private *priv, > const struct pciserial_board *board, > struct uart_8250_port *port, int idx) > { > + struct pci_dev *dev = priv->dev; > + unsigned short device = dev->device; > unsigned int bar = FL_GET_BASE(board->flags); > int offset; > > + /* > + * For the device IDs of MOXA PCIe boards match the pattern 0x*1** and 0x*3**, > + * these boards support switching interface between RS422/RS485 using TIOCSRS485. > + */ > + if (pci_moxa_match_second_digit(device, 0x0100) || > + pci_moxa_match_second_digit(device, 0x0300)) {
if (pci_moxa_supported_rs(dev) & (MOXA_SUPP_RS422 | MOXA_SUPP_RS485) == MOXA_SUPP_RS422 | MOXA_SUPP_RS485)
or maybe even simple:
if (pci_moxa_supported_rs(dev) & MOXA_SUPP_RS485) ?
> + port->port.rs485_config = pci_moxa_rs485_config; > + port->port.rs485_supported = pci_moxa_rs485_supported; > + > + if (pci_moxa_match_second_digit(device, 0x0300))
if (!(pci_moxa_supported_rs(dev) & MOXA_SUPP_RS232))
> + port->port.rs485.flags |= SER_RS485_ENABLED | SER_RS485_TERMINATE_BUS; > + } > if (board->num_ports == 4 && idx == 3) > offset = 7 * board->uart_offset; > else
-- js suse labs
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