On Sat, 1 Oct 2022, Kumaravel Thiagarajan wrote:
> pci1xxxx's quad-uart function has the capability to wake up the host from
> suspend state. Enable wakeup before entering into suspend and disable
> wakeup on resume.
>
> Signed-off-by: Kumaravel Thiagarajan <kumaravel.thiagarajan@xxxxxxxxxxxxx>
> ---
> Changes in v2:
> - Use DEFINE_SIMPLE_DEV_PM_OPS instead of SIMPLE_DEV_PM_OPS.
> - Use pm_sleep_ptr instead of CONFIG_PM_SLEEP.
> - Change the return data type of pci1xxxx_port_suspend to bool from int.
> ---
> drivers/tty/serial/8250/8250_pci1xxxx.c | 112 ++++++++++++++++++++++++
> 1 file changed, 112 insertions(+)
>
> diff --git a/drivers/tty/serial/8250/8250_pci1xxxx.c b/drivers/tty/serial/8250/8250_pci1xxxx.c
> index 999e5a284266..0a0459f66177 100644
> --- a/drivers/tty/serial/8250/8250_pci1xxxx.c
> +++ b/drivers/tty/serial/8250/8250_pci1xxxx.c
> @@ -352,6 +352,112 @@ static void pci1xxxx_irq_assign(struct pci1xxxx_8250 *priv,
> }
> }
>
> +static bool pci1xxxx_port_suspend(int line)
> +{
> + struct uart_8250_port *up = serial8250_get_port(line);
> + struct uart_port *port = &up->port;
> + unsigned long flags;
> + u8 wakeup_mask;
> + bool ret = false;
> +
> + if (port->suspended == 0 && port->dev) {
> + wakeup_mask = readb(up->port.membase + UART_WAKE_MASK_REG);
> +
> + spin_lock_irqsave(&port->lock, flags);
> + port->mctrl &= ~TIOCM_OUT2;
> + port->ops->set_mctrl(port, port->mctrl);
> + spin_unlock_irqrestore(&port->lock, flags);
> +
> + if ((wakeup_mask & UART_WAKE_SRCS) != UART_WAKE_SRCS)
> + ret = true;
> + }
> +
> + writeb(UART_WAKE_SRCS, port->membase + UART_WAKE_REG);
> +
> + return ret;
> +}
> +
> +static void pci1xxxx_port_resume(int line)
> +{
> + struct uart_8250_port *up = serial8250_get_port(line);
> + struct uart_port *port = &up->port;
> + unsigned long flags;
> +
> + writeb(UART_WAKE_SRCS, port->membase + UART_WAKE_REG);
> +
> + if (port->suspended == 0) {
Is this check the right way around?
> + spin_lock_irqsave(&port->lock, flags);
> + port->mctrl |= TIOCM_OUT2;
> + port->ops->set_mctrl(port, port->mctrl);
> + spin_unlock_irqrestore(&port->lock, flags);
> + }
> +}
> +
> +static int pci1xxxx_suspend(struct device *dev)
> +{
> + struct pci1xxxx_8250 *priv = dev_get_drvdata(dev);
> + struct pci_dev *pcidev = to_pci_dev(dev);
> + unsigned int data;
> + void __iomem *p;
> + bool wakeup = false;
> + int i;
> +
> + for (i = 0; i < priv->nr; i++) {
> + if (priv->line[i] >= 0) {
> + serial8250_suspend_port(priv->line[i]);
> + wakeup |= pci1xxxx_port_suspend(priv->line[i]);
So first serial8250_suspend_port() calls into uart_suspend_port() that
sets port->suspended to 1, then pci1xxxx_port_suspend() checks if it's 0.
Is this intentional?
--
i.
