Commit 8cf31a99 authored by Kumaravel Thiagarajan's avatar Kumaravel Thiagarajan Committed by Greg Kroah-Hartman
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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: default avatarTharun Kumar P <tharunkumar.pasumarthi@microchip.com>
Signed-off-by: default avatarTharun Kumar P <tharunkumar.pasumarthi@microchip.com>
Signed-off-by: default avatarKumaravel Thiagarajan <kumaravel.thiagarajan@microchip.com>
Link: https://lore.kernel.org/r/20230207164814.3104605-5-kumaravel.thiagarajan@microchip.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 08cedda0

drivers/tty/serial/8250/8250_pci1xxxx.c

+115 −0
Original line number Diff line number Diff line
@@ -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);