Hi Thierry,
On Wed, 29 Jan 2025 at 17:52, Thierry Bultel
<thierry.bultel.yh@xxxxxxxxxxxxxx> wrote:
> Define a new RZSCI port type, and the RSCI 32 bits registers set.
> The RZ/T2H SCI has a a fifo, and a quite different set of registers
> from the orginal SH SCI ones.
> DMA is not supported yet.
>
> Signed-off-by: Thierry Bultel <thierry.bultel.yh@xxxxxxxxxxxxxx>
Thanks for your patch!
> --- /dev/null
> +++ b/drivers/tty/serial/rzsci.c
> @@ -0,0 +1,484 @@
> +/* RDR (Receive Data Register) */
> +#define RDR_FER BIT(28) /* Framing Error */
> +#define RDR_PER BIT(27) /* Parity Error */
> +#define RDR_ORER BIT(24) /* Overrun Error */
> +#define RDR_FFER BIT(12) /* FIFO Framing Error */
> +#define RDR_FPER BIT(11) /* FIFO Parity Error */
> +#define RDR_DR BIT(10) /* Incoming Data Ready */
> +#define RDR_MPB BIT(9) /* Multiprocessor Bit */
None of the above are used...
> +#define RDR_RDAT_MSK GENMASK(8, 0)
...
> +static void rzsci_receive_chars(struct uart_port *port)
> +{
> + struct tty_port *tport = &port->state->port;
> + int i, count, copied = 0;
> + u32 status, frsr_status = 0;
> + unsigned char flag;
> +
> + status = rzsci_serial_in(port, CSR);
> + frsr_status = rzsci_serial_in(port, FRSR);
> +
> + if (!(status & CSR_RDRF) && !(frsr_status & FRSR_DR))
> + return;
> +
> + while (1) {
> + /* Don't copy more bytes than there is room for in the buffer */
> + count = tty_buffer_request_room(tport, rzsci_rxfill(port));
> +
> + /* If for any reason we can't copy more data, we're done! */
> + if (count == 0)
> + break;
> +
> + for (i = 0; i < count; i++) {
> + char c;
> +
> + status = rzsci_serial_in(port, CSR);
Isn't the point of the RDR_* status bits in the top part of the RDR
register that you don't need to read the CSR register anymore?
> + c = rzsci_serial_in(port, RDR) & RDR_RDAT_MSK;
Note that this drops bit 8.
> +
> + if (uart_handle_sysrq_char(port, c)) {
> + count--;
> + i--;
> + continue;
> + }
> +
> + /* Store data and status */
> + if (status & CSR_FER) {
> + flag = TTY_FRAME;
> + port->icount.frame++;
> + } else if (status & CSR_PER) {
> + flag = TTY_PARITY;
> + port->icount.parity++;
> + } else
> + flag = TTY_NORMAL;
> +
> + tty_insert_flip_char(tport, c, flag);
> + }
> +
> + rzsci_serial_in(port, CSR); /* dummy read */
> + rzsci_clear_DRxC(port);
> +
> + copied += count;
> + port->icount.rx += count;
> + }
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
