serial: 8250_pci1xxxx: Add power management functions to quad-uart driver

pci1xxxx's quad-uart function has the capability to wake up UART
from suspend state. Enable wakeup before entering into suspend and
disable wakeup on resume.

Co-developed-by: Tharun Kumar P <tharunkumar.pasumarthi@microchip.com>
Signed-off-by: Tharun Kumar P <tharunkumar.pasumarthi@microchip.com>
Signed-off-by: Kumaravel Thiagarajan <kumaravel.thiagarajan@microchip.com>
Link: https://lore.kernel.org/r/20230207164814.3104605-5-kumaravel.thiagarajan@microchip.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/8250/8250_pci1xxxx.c b/drivers/tty/serial/8250/8250_pci1xxxx.c
index 58f47d18f7d8b658c511dd4a9ec5d049c4189037..a3b25779d9219d7267bfffd85897264b6082d8a8 100644 (file)
--- a/drivers/tty/serial/8250/8250_pci1xxxx.c
+++ b/drivers/tty/serial/8250/8250_pci1xxxx.c
@@ -212,6 +212,116 @@ static const struct serial_rs485 pci1xxxx_rs485_supported = {
        /* Delay RTS before send is not supported */
 };
 
+static bool pci1xxxx_port_suspend(int line)
+{
+       struct uart_8250_port *up = serial8250_get_port(line);
+       struct uart_port *port = &up->port;
+       struct tty_port *tport = &port->state->port;
+       unsigned long flags;
+       bool ret = false;
+       u8 wakeup_mask;
+
+       mutex_lock(&tport->mutex);
+       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);
+
+               ret = (wakeup_mask & UART_WAKE_SRCS) != UART_WAKE_SRCS;
+       }
+
+       writeb(UART_WAKE_SRCS, port->membase + UART_WAKE_REG);
+       mutex_unlock(&tport->mutex);
+
+       return ret;
+}
+
+static void pci1xxxx_port_resume(int line)
+{
+       struct uart_8250_port *up = serial8250_get_port(line);
+       struct uart_port *port = &up->port;
+       struct tty_port *tport = &port->state->port;
+       unsigned long flags;
+
+       mutex_lock(&tport->mutex);
+       writeb(UART_BLOCK_SET_ACTIVE, port->membase + UART_ACTV_REG);
+       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);
+       }
+       mutex_unlock(&tport->mutex);
+}
+
+static int pci1xxxx_suspend(struct device *dev)
+{
+       struct pci1xxxx_8250 *priv = dev_get_drvdata(dev);
+       struct pci_dev *pcidev = to_pci_dev(dev);
+       bool wakeup = false;
+       unsigned int data;
+       void __iomem *p;
+       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)
+               writeb(UART_PCI_CTRL_D3_CLK_ENABLE, p + UART_PCI_CTRL_REG);
+
+       iounmap(p);
+       device_set_wakeup_enable(dev, true);
+       pci_wake_from_d3(pcidev, true);
+
+       return 0;
+}
+
+static int pci1xxxx_resume(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;
+       int 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);
+       iounmap(p);
+
+       for (i = 0; i < priv->nr; i++) {
+               if (priv->line[i] >= 0) {
+                       pci1xxxx_port_resume(priv->line[i]);
+                       serial8250_resume_port(priv->line[i]);
+               }
+       }
+
+       return 0;
+}
+
 static int pci1xxxx_setup(struct pci_dev *pdev,
                          struct uart_8250_port *port, int port_idx)
 {
@@ -352,6 +462,8 @@ static void pci1xxxx_serial_remove(struct pci_dev *dev)
        pci_iounmap(dev, priv->membase);
 }
 
+static DEFINE_SIMPLE_DEV_PM_OPS(pci1xxxx_pm_ops, pci1xxxx_suspend, pci1xxxx_resume);
+
 static const struct pci_device_id pci1xxxx_pci_tbl[] = {
        { PCI_VDEVICE(EFAR, PCI_DEVICE_ID_EFAR_PCI11010) },
        { PCI_VDEVICE(EFAR, PCI_DEVICE_ID_EFAR_PCI11101) },
@@ -366,6 +478,9 @@ static struct pci_driver pci1xxxx_pci_driver = {
        .name = "pci1xxxx serial",
        .probe = pci1xxxx_serial_probe,
        .remove = pci1xxxx_serial_remove,
+       .driver = {
+               .pm     = pm_sleep_ptr(&pci1xxxx_pm_ops),
+       },
        .id_table = pci1xxxx_pci_tbl,
 };
 module_pci_driver(pci1xxxx_pci_driver);