Re: [PATCH RFC 07/10] tty: serial: Add Cortina Systems CS75xx UART driver

From: Linus Walleij

Date: Wed Sep 30 2026 - 07:06:34 EST


Hi Filipp,

thanks for your patch!

On Wed, Sep 30, 2026 at 9:00 AM Fil Dunsky via B4 Relay
<devnull+filipp.dunsky.gmail.com@xxxxxxxxxx> wrote:

> From: Fil Dunsky <filipp.dunsky@xxxxxxxxx>
>
> Add a driver for the UARTs of the Cortina Systems CS75xx (Goldengate G2)
> SoCs. The block has transmit and receive FIFOs with full/empty status,
> a 24-bit baud rate divider clocked from the peripheral (APB) clock, a
> receive sampling point register and one interrupt line per port with
> per-cause enable and write-one-to-clear status registers.
>
> The driver is a rewrite of the vendor driver shipped with the Linux
> 2.6.36 and 4.9 based vendor kernels, using the current serial core API
> (uart_port_tx(), port lock helpers, deferred sysrq handling) and devm
> resource management. It supports the system console and earlycon.
> Hardware flow control is not supported.
>
> The ports are named ttyCS so that the driver can coexist with the 8250
> driver in multiplatform kernels, and PORT_GENERIC is used rather than
> allocating a new port type.
>
> Signed-off-by: Fil Dunsky <filipp.dunsky@xxxxxxxxx>

Look at this in your Linux tree:
git log -p b61c8bf4694b5115766849378dcb8787ff54e65e

This is essentially a resurrection of that driver. It was deleted again
because it was merged prematurely. Cortina never came back to revise
the driver. (People run out of steam. Such things happen.)

Anyways, clearly this driver is not just for CS75xx so name it
cortina-uart.c simply, and update symbols accordingly. Kconfig
should be SERIAL_CORTINA etc.

Maybe
even the DT compatible should be something more generic.

Yours,
Linus Walleij