Hi Biju,
On Fri, Mar 24, 2023 at 11:02 AM Biju Das <biju.das.jz@xxxxxxxxxxxxxx> wrote:
> Add SCIF DMA tx support for RZ/G2L alike SoCs.
>
> RZ/G2L alike SoC use the same signal for both interrupt and DMA
> transfer requests, so we must disable line interrupts(tx and tx end)
> while transferring DMA and enable the TIE source interrupt.
>
> Based on a patch in the BSP by Long Luu
> <long.luu.ur@xxxxxxxxxxx>
>
> Signed-off-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
Thanks for your patch!
> --- a/drivers/tty/serial/sh-sci.c
> +++ b/drivers/tty/serial/sh-sci.c
> @@ -172,6 +172,13 @@ to_sci_port(struct uart_port *uart)
> return container_of(uart, struct sci_port, port);
> }
>
> +static inline bool is_rz_scif_port(struct uart_port *port, struct sci_port *s)
> +{
> + const struct plat_sci_port *p = s->cfg;
> +
> + return port->type == PORT_SCIF && p->regtype == SCIx_RZ_SCIFA_REGTYPE;
The latter implies the former, so you can drop the first check.
After that, the check becomes sufficiently simple to inline?
> +}
> +
> static const struct sci_port_params sci_port_params[SCIx_NR_REGTYPES] = {
> /*
> * Common SCI definitions, dependent on the port's regshift
> @@ -588,6 +595,16 @@ static void sci_start_tx(struct uart_port *port)
>
> if (s->chan_tx && !uart_circ_empty(&s->port.state->xmit) &&
> dma_submit_error(s->cookie_tx)) {
> + if (is_rz_scif_port(port, s)) {
> + /* Switch irq from SCIF to DMA */
> + disable_irq(s->irqs[SCIx_TXI_IRQ]);
> + disable_irq(s->irqs[SCIx_TEI_IRQ]);
> +
> + /* DMA need TIE enable */
> + ctrl = serial_port_in(port, SCSCR);
> + serial_port_out(port, SCSCR, ctrl | SCSCR_TIE);
Enabling TIE is also done for SCIFA below (out of visible context).
Perhaps you can combine?
> + }
> +
> s->cookie_tx = 0;
> schedule_work(&s->work_tx);
> }
> @@ -1214,9 +1231,16 @@ static void sci_dma_tx_complete(void *arg)
> schedule_work(&s->work_tx);
> } else {
> s->cookie_tx = -EINVAL;
> - if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
> + if (port->type == PORT_SCIFA || port->type == PORT_SCIFB ||
> + is_rz_scif_port(port, s)) {
> u16 ctrl = serial_port_in(port, SCSCR);
> serial_port_out(port, SCSCR, ctrl & ~SCSCR_TIE);
> + if (port->type == PORT_SCIF) {
"if (s->cfg->regtype == SCIx_RZ_SCIFA_REGTYPE)"?
> + /* Switch irq from DMA to SCIF */
> + dmaengine_pause(s->chan_tx_saved);
> + enable_irq(s->irqs[SCIx_TXI_IRQ]);
> + enable_irq(s->irqs[SCIx_TEI_IRQ]);
> + }
> }
> }
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
