diff options
| -rw-r--r-- | drivers/tty/serial/xilinx_uartps.c | 114 |
1 files changed, 114 insertions, 0 deletions
diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c index 82195040e906..9ecd8ea4f3ae 100644 --- a/drivers/tty/serial/xilinx_uartps.c +++ b/drivers/tty/serial/xilinx_uartps.c @@ -1198,6 +1198,119 @@ console_initcall(xuartps_console_init); #endif /* CONFIG_SERIAL_XILINX_PS_UART_CONSOLE */ +#ifdef CONFIG_PM_SLEEP +/** + * xuartps_suspend - suspend event + * @device: Pointer to the device structure + * + * Returns 0 + */ +static int xuartps_suspend(struct device *device) +{ + struct uart_port *port = dev_get_drvdata(device); + struct tty_struct *tty; + struct device *tty_dev; + int may_wake = 0; + + /* Get the tty which could be NULL so don't assume it's valid */ + tty = tty_port_tty_get(&port->state->port); + if (tty) { + tty_dev = tty->dev; + may_wake = device_may_wakeup(tty_dev); + tty_kref_put(tty); + } + + /* + * Call the API provided in serial_core.c file which handles + * the suspend. + */ + uart_suspend_port(&xuartps_uart_driver, port); + if (console_suspend_enabled && !may_wake) { + struct xuartps *xuartps = port->private_data; + + clk_disable(xuartps->refclk); + clk_disable(xuartps->aperclk); + } else { + unsigned long flags = 0; + + spin_lock_irqsave(&port->lock, flags); + /* Empty the receive FIFO 1st before making changes */ + while (!(xuartps_readl(XUARTPS_SR_OFFSET) & XUARTPS_SR_RXEMPTY)) + xuartps_readl(XUARTPS_FIFO_OFFSET); + /* set RX trigger level to 1 */ + xuartps_writel(1, XUARTPS_RXWM_OFFSET); + /* disable RX timeout interrups */ + xuartps_writel(XUARTPS_IXR_TOUT, XUARTPS_IDR_OFFSET); + spin_unlock_irqrestore(&port->lock, flags); + } + + return 0; +} + +/** + * xuartps_resume - Resume after a previous suspend + * @device: Pointer to the device structure + * + * Returns 0 + */ +static int xuartps_resume(struct device *device) +{ + struct uart_port *port = dev_get_drvdata(device); + unsigned long flags = 0; + u32 ctrl_reg; + struct tty_struct *tty; + struct device *tty_dev; + int may_wake = 0; + + /* Get the tty which could be NULL so don't assume it's valid */ + tty = tty_port_tty_get(&port->state->port); + if (tty) { + tty_dev = tty->dev; + may_wake = device_may_wakeup(tty_dev); + tty_kref_put(tty); + } + + if (console_suspend_enabled && !may_wake) { + struct xuartps *xuartps = port->private_data; + + clk_enable(xuartps->aperclk); + clk_enable(xuartps->refclk); + + spin_lock_irqsave(&port->lock, flags); + + /* Set TX/RX Reset */ + xuartps_writel(xuartps_readl(XUARTPS_CR_OFFSET) | + (XUARTPS_CR_TXRST | XUARTPS_CR_RXRST), + XUARTPS_CR_OFFSET); + while (xuartps_readl(XUARTPS_CR_OFFSET) & + (XUARTPS_CR_TXRST | XUARTPS_CR_RXRST)) + cpu_relax(); + + /* restore rx timeout value */ + xuartps_writel(rx_timeout, XUARTPS_RXTOUT_OFFSET); + /* Enable Tx/Rx */ + ctrl_reg = xuartps_readl(XUARTPS_CR_OFFSET); + xuartps_writel( + (ctrl_reg & ~(XUARTPS_CR_TX_DIS | XUARTPS_CR_RX_DIS)) | + (XUARTPS_CR_TX_EN | XUARTPS_CR_RX_EN), + XUARTPS_CR_OFFSET); + + spin_unlock_irqrestore(&port->lock, flags); + } else { + spin_lock_irqsave(&port->lock, flags); + /* restore original rx trigger level */ + xuartps_writel(rx_trigger_level, XUARTPS_RXWM_OFFSET); + /* enable RX timeout interrupt */ + xuartps_writel(XUARTPS_IXR_TOUT, XUARTPS_IER_OFFSET); + spin_unlock_irqrestore(&port->lock, flags); + } + + return uart_resume_port(&xuartps_uart_driver, port); +} +#endif /* ! CONFIG_PM_SLEEP */ + +static SIMPLE_DEV_PM_OPS(xuartps_dev_pm_ops, xuartps_suspend, xuartps_resume); + /** Structure Definitions */ static struct uart_driver xuartps_uart_driver = { @@ -1348,6 +1461,7 @@ static struct platform_driver xuartps_platform_driver = { .owner = THIS_MODULE, .name = XUARTPS_NAME, /* Driver name */ .of_match_table = xuartps_of_match, + .pm = &xuartps_dev_pm_ops, }, }; |