Re: [PATCH v4] serial/8250: Add support for NI-Serial PXI/PXIe+485 devices

From: Greg KH
Date: Thu Jul 25 2019 - 14:05:12 EST


On Fri, Jul 05, 2019 at 06:15:28AM -0700, jeyentam wrote:
> Add support for NI-Serial PXIe-RS232, PXI-RS485 and PXIe-RS485 devices.
>
> Signed-off-by: Je Yen Tam <je.yen.tam@xxxxxx>
> ---
> v3 -> v4:
> - Add changes description.
>
> v2 -> v3:
> - Add "full" name for author
> - Use BIT() macro for bits definition
> - Remove unnecessary WARN_ON()
> - Change debugging interface to ftrace
> - Fix indentation
> - Add NI PXIe-RS232 and PXI/PXIe-RS485 device IDs #defines
>
> v1 -> v2:
> - Fix unintended indentation
>
> v1:
> - Add and rename #defines for 16550 UART Port Control Register
> - Add configuration for RS485 port.
> - Add device setup for NI PXI/PXIe-RS485 family.
> - Add PCI board attributes for NI PXIe-RS232 and PXI/PXIe-RS485 devices.
>
> drivers/tty/serial/8250/8250_pci.c | 298 ++++++++++++++++++++++++++++-
> 1 file changed, 294 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/tty/serial/8250/8250_pci.c b/drivers/tty/serial/8250/8250_pci.c
> index df41397de478..23fe3b7197ad 100644
> --- a/drivers/tty/serial/8250/8250_pci.c
> +++ b/drivers/tty/serial/8250/8250_pci.c
> @@ -730,8 +730,16 @@ static int pci_ni8430_init(struct pci_dev *dev)
> }
>
> /* UART Port Control Register */
> -#define NI8430_PORTCON 0x0f
> -#define NI8430_PORTCON_TXVR_ENABLE (1 << 3)
> +#define NI16550_PCR_OFFSET 0x0f
> +#define NI16550_PCR_RS422 0x00
> +#define NI16550_PCR_ECHO_RS485 0x01
> +#define NI16550_PCR_DTR_RS485 0x02
> +#define NI16550_PCR_AUTO_RS485 0x03
> +#define NI16550_PCR_WIRE_MODE_MASK 0x03
> +#define NI16550_PCR_TXVR_ENABLE_BIT BIT(3)
> +#define NI16550_PCR_RS485_TERMINATION_BIT BIT(6)
> +#define NI16550_ACR_DTR_AUTO_DTR (0x2 << 3)
> +#define NI16550_ACR_DTR_MANUAL_DTR (0x0 << 3)
>
> static int
> pci_ni8430_setup(struct serial_private *priv,
> @@ -753,14 +761,123 @@ pci_ni8430_setup(struct serial_private *priv,
> return -ENOMEM;
>
> /* enable the transceiver */
> - writeb(readb(p + offset + NI8430_PORTCON) | NI8430_PORTCON_TXVR_ENABLE,
> - p + offset + NI8430_PORTCON);
> + writeb(readb(p + offset + NI16550_PCR_OFFSET) | NI16550_PCR_TXVR_ENABLE_BIT,
> + p + offset + NI16550_PCR_OFFSET);
>
> iounmap(p);
>
> return setup_port(priv, port, bar, offset, board->reg_shift);
> }
>
> +static int pci_ni8431_config_rs485(struct uart_port *port,
> + struct serial_rs485 *rs485)
> +{
> + u8 pcr, acr;
> +
> + struct uart_8250_port *up;

No blank lines between variable definitions please.

> +
> + up = container_of(port, struct uart_8250_port, port);
> +
> + acr = up->acr;
> +
> + trace_printk("start ni16550_config_rs485\n");

This line is not needed, right?

> +
> + pcr = port->serial_in(port, NI16550_PCR_OFFSET);
> + pcr &= ~NI16550_PCR_WIRE_MODE_MASK;
> +
> + if (rs485->flags & SER_RS485_ENABLED) {
> + /* RS-485 */
> + if ((rs485->flags & SER_RS485_RX_DURING_TX) &&
> + (rs485->flags & SER_RS485_RTS_ON_SEND)) {
> + dev_dbg(port->dev, "Invalid 2-wire mode\n");
> + return -EINVAL;
> + }
> +
> + if (rs485->flags & SER_RS485_RX_DURING_TX) {
> + /* Echo */
> + dev_vdbg(port->dev, "2-wire DTR with echo\n");
> + pcr |= NI16550_PCR_ECHO_RS485;
> + acr |= NI16550_ACR_DTR_MANUAL_DTR;
> + } else {
> + /* Auto or DTR */
> + if (rs485->flags & SER_RS485_RTS_ON_SEND) {
> + /* Auto */
> + dev_vdbg(port->dev, "2-wire Auto\n");
> + pcr |= NI16550_PCR_AUTO_RS485;
> + acr |= NI16550_ACR_DTR_AUTO_DTR;
> + } else {
> + /* DTR-controlled */
> + /* No Echo */
> + dev_vdbg(port->dev, "2-wire DTR no echo\n");
> + pcr |= NI16550_PCR_DTR_RS485;
> + acr |= NI16550_ACR_DTR_MANUAL_DTR;
> + }
> + }
> + } else {
> + /* RS-422 */
> + dev_vdbg(port->dev, "4-wire\n");
> + pcr |= NI16550_PCR_RS422;
> + acr |= NI16550_ACR_DTR_MANUAL_DTR;
> + }
> +
> + dev_dbg(port->dev, "write pcr: 0x%08x\n", pcr);
> + port->serial_out(port, NI16550_PCR_OFFSET, pcr);
> +
> + up->acr = acr;
> + port->serial_out(port, UART_SCR, UART_ACR);
> + port->serial_out(port, UART_ICR, up->acr);
> +
> + /* Update the cache. */
> + port->rs485 = *rs485;
> +
> + trace_printk("end ni16550_config_rs485\n");

Also drop this.

thanks,

greg k-h