On Tue, 7 Jan 2025 15:29:47 +0100
Andre Werner <andre.werner@xxxxxxxxxxxxxxxxxxxxx> wrote:
Hi Andre,
> Fall back to polling mode if no interrupt is configured because not
> possible. If "interrupts" property is missing in devicetree the driver
> uses a delayed worker to pull state of interrupt status registers.
"not possible" is confusing. Maybe:
"Fall back to polling mode if interrupt pin is not connected
or available."
You also could change the commit title in a similar way (Add polling
feature if no IRQ pin is available).
I would also replace "feature" with "mode" for consistency with your
other comments below.
>
> Signed-off-by: Andre Werner <andre.werner@xxxxxxxxxxxxxxxxxxxxx>
> ---
> V2:
> - Change warning for polling mode to debug log entry
> - Correct typo: Resuse -> Reuse
> - Format define with missing tabs for SC16IS7XX_POLL_PERIOD
> - Format struct declaration sc16is7xx_one_config with missing tabs for polling and shutdown
> - Adapt dtbinding with new polling feature
> V3:
> - Use suffix with units and drop a comment SC16IS7XX_POLL_PERIOD_MS. Sorry for that miss.
> - Make Kernel lowercase.
> ---
> ---
> drivers/tty/serial/sc16is7xx.c | 40 ++++++++++++++++++++++++++++++++++
> 1 file changed, 40 insertions(+)
>
> diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c
> index a3093e09309f..57be5d55205a 100644
> --- a/drivers/tty/serial/sc16is7xx.c
> +++ b/drivers/tty/serial/sc16is7xx.c
> @@ -314,6 +314,7 @@
> #define SC16IS7XX_FIFO_SIZE (64)
> #define SC16IS7XX_GPIOS_PER_BANK 4
>
> +#define SC16IS7XX_POLL_PERIOD_MS 10
> #define SC16IS7XX_RECONF_MD BIT(0)
> #define SC16IS7XX_RECONF_IER BIT(1)
> #define SC16IS7XX_RECONF_RS485 BIT(2)
> @@ -348,6 +349,9 @@ struct sc16is7xx_port {
> u8 mctrl_mask;
> struct kthread_worker kworker;
> struct task_struct *kworker_task;
> + struct kthread_delayed_work poll_work;
> + bool polling;
> + bool shutdown;
> struct sc16is7xx_one p[];
> };
>
> @@ -861,6 +865,19 @@ static irqreturn_t sc16is7xx_irq(int irq, void *dev_id)
> return IRQ_HANDLED;
> }
>
> +static void sc16is7xx_transmission_poll(struct kthread_work *work)
Maybe drop "transmission", as this is used for tx/rx?
And other kthread work functions use _proc suffix, so rename to follow
the same convention -> sc16is7xx_poll_proc()
They also use "wk" as argument name, so also rename it for consistency.
> +{
> + struct sc16is7xx_port *s = container_of(work, struct sc16is7xx_port, poll_work.work);
> +
> + /* Reuse standard IRQ handler. Interrupt ID is unused in this context. */
> + sc16is7xx_irq(0, s);
> +
> + /* Setup delay based on SC16IS7XX_POLL_PERIOD_MS */
> + if (!s->shutdown)
> + kthread_queue_delayed_work(&s->kworker, &s->poll_work,
> + msecs_to_jiffies(SC16IS7XX_POLL_PERIOD_MS));
> +}
> +
> static void sc16is7xx_tx_proc(struct kthread_work *ws)
> {
> struct uart_port *port = &(to_sc16is7xx_one(ws, tx_work)->port);
> @@ -1149,6 +1166,7 @@ static int sc16is7xx_config_rs485(struct uart_port *port, struct ktermios *termi
> static int sc16is7xx_startup(struct uart_port *port)
> {
> struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
> + struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
> unsigned int val;
> unsigned long flags;
>
> @@ -1210,6 +1228,11 @@ static int sc16is7xx_startup(struct uart_port *port)
> uart_port_lock_irqsave(port, &flags);
> sc16is7xx_enable_ms(port);
> uart_port_unlock_irqrestore(port, flags);
Insert blank line
> + if (s->polling) {
> + s->shutdown = false;
> + kthread_queue_delayed_work(&s->kworker, &s->poll_work,
> + msecs_to_jiffies(SC16IS7XX_POLL_PERIOD_MS));
> + }
>
> return 0;
> }
> @@ -1232,6 +1255,10 @@ static void sc16is7xx_shutdown(struct uart_port *port)
>
> sc16is7xx_power(port, 0);
>
> + if (s->polling) {
> + s->shutdown = true;
Can we avoid using this shutdown variable?
