Re: [PATCH v1 tty-next 2/2] 8250: microchip: pci1xxxx: Add power management functions to pci1xxxx's quad-uart driver.

From: Ilpo Järvinen
Date: Wed Aug 31 2022 - 05:53:51 EST


On Tue, 30 Aug 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 upon resume.
>
> Signed-off-by: Kumaravel Thiagarajan <kumaravel.thiagarajan@xxxxxxxxxxxxx>
> ---
> drivers/tty/serial/8250/8250_pci1xxxx.c | 122 ++++++++++++++++++++++++
> 1 file changed, 122 insertions(+)
>
> diff --git a/drivers/tty/serial/8250/8250_pci1xxxx.c b/drivers/tty/serial/8250/8250_pci1xxxx.c
> index 56852ae0585e..38c2a6a9e5d5 100644
> --- a/drivers/tty/serial/8250/8250_pci1xxxx.c
> +++ b/drivers/tty/serial/8250/8250_pci1xxxx.c
> @@ -70,6 +70,7 @@
>
> #define UART_PCI_CTRL_REG 0x80
> #define UART_PCI_CTRL_SET_MULTIPLE_MSI BIT(4)
> +#define UART_PCI_CTRL_D3_CLK_ENABLE BIT(0)

Reorder.

> +static char pci1xxxx_port_suspend(int line)

Why char???

> +{
> + struct uart_8250_port *up = serial8250_get_port(line);
> + struct uart_port *port = &up->port;
> + unsigned long flags;
> + u8 wakeup_mask;
> + char ret = 0;
> +
> + 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 = 0x01;
> + else
> + ret = 0x00;

Is it a bool or should you name these it with a #define?

> + }
> +
> + writeb(UART_WAKE_SRCS, port->membase + UART_WAKE_REG);
> +
> + return ret;
> +}
> +
> +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) {
> + 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;
> + char wakeup = 0;
> + 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]);
> + }
> + }
> +
> + p = pci_ioremap_bar(pcidev, 0);
> + if (!p) {
> + dev_err(dev, "remapping of bar 0 memory failed");
> + return -ENOMEM;
> + }
> +
> + data = readl(p + UART_RESET_REG);
> + writel(data | UART_RESET_D3_RESET_DISABLE, p + UART_RESET_REG);
> +
> + if (wakeup)

It looks you'd want bool instead of char here.


--
i.