1 // SPDX-License-Identifier: GPL-2.0
15  * We re-use the already existing "bug handling" lsr_saved_flags
16  * field to carry the "what we just did" information from the one
33 	spin_lock_irqsave(&up->port.lock, flags);  in fsl8250_handle_irq()
35 	iir = port->serial_in(port, UART_IIR);  in fsl8250_handle_irq()
37 		spin_unlock_irqrestore(&up->port.lock, flags);  in fsl8250_handle_irq()
46 	 * In practise it's less (around 500) because of hardware  in fsl8250_handle_irq()
54 	if (unlikely(up->lsr_saved_flags & UART_LSR_BI)) {  in fsl8250_handle_irq()
55 		up->lsr_saved_flags &= ~UART_LSR_BI;  in fsl8250_handle_irq()
56 		port->serial_in(port, UART_RX);  in fsl8250_handle_irq()
57 		spin_unlock_irqrestore(&up->port.lock, flags);  in fsl8250_handle_irq()
61 	lsr = orig_lsr = up->port.serial_in(&up->port, UART_LSR);  in fsl8250_handle_irq()
65 	    (up->ier & (UART_IER_RLSI | UART_IER_RDI))) {  in fsl8250_handle_irq()
70 	if ((orig_lsr & UART_LSR_OE) && (up->overrun_backoff_time_ms > 0)) {  in fsl8250_handle_irq()
73 		up->ier = port->serial_in(port, UART_IER);  in fsl8250_handle_irq()
74 		if (up->ier & (UART_IER_RLSI | UART_IER_RDI)) {  in fsl8250_handle_irq()
75 			port->ops->stop_rx(port);  in fsl8250_handle_irq()
80 			cancel_delayed_work(&up->overrun_backoff);  in fsl8250_handle_irq()
83 		delay = msecs_to_jiffies(up->overrun_backoff_time_ms);  in fsl8250_handle_irq()
84 		schedule_delayed_work(&up->overrun_backoff, delay);  in fsl8250_handle_irq()
89 	if ((lsr & UART_LSR_THRE) && (up->ier & UART_IER_THRI))  in fsl8250_handle_irq()
92 	up->lsr_saved_flags |= orig_lsr & UART_LSR_BI;  in fsl8250_handle_irq()
94 	uart_unlock_and_check_sysrq_irqrestore(&up->port, flags);  in fsl8250_handle_irq()
109 	struct device *dev = &pdev->dev;  in fsl8250_acpi_probe()
117 		return -EINVAL;  in fsl8250_acpi_probe()
126 	ret = device_property_read_u32(dev, "clock-frequency",  in fsl8250_acpi_probe()
133 	port8250.port.mapbase           = regs->start;  in fsl8250_acpi_probe()
148 		return -ENOMEM;  in fsl8250_acpi_probe()
152 		return -ENOMEM;  in fsl8250_acpi_probe()
154 	data->line = serial8250_register_8250_port(&port8250);  in fsl8250_acpi_probe()
155 	if (data->line < 0)  in fsl8250_acpi_probe()
156 		return data->line;  in fsl8250_acpi_probe()
166 	serial8250_unregister_port(data->line);  in fsl8250_acpi_remove()
178 		.name			= "fsl-16550-uart",