1 // SPDX-License-Identifier: GPL-2.0
3 * SGI IOC3 8250 UART driver
5 * Copyright (C) 2019 Thomas Bogendoerfer <tbogendoerfer@suse.de>
7 * based on code Copyright (C) 2005 Stanislaw Skowronek <skylark@unaligned.org>
8 * Copyright (C) 2014 Joshua Kinard <kumba@gentoo.org>
11 #include <linux/module.h>
12 #include <linux/errno.h>
14 #include <linux/platform_device.h>
18 #define IOC3_UARTCLK (22000000 / 3)
20 struct ioc3_8250_data {
24 static unsigned int ioc3_serial_in(struct uart_port *p, int offset)
26 return readb(p->membase + (offset ^ 3));
29 static void ioc3_serial_out(struct uart_port *p, int offset, int value)
31 writeb(value, p->membase + (offset ^ 3));
34 static int serial8250_ioc3_probe(struct platform_device *pdev)
36 struct ioc3_8250_data *data;
37 struct uart_8250_port up;
39 void __iomem *membase;
42 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
46 data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
50 membase = devm_ioremap(&pdev->dev, r->start, resource_size(r));
54 irq = platform_get_irq(pdev, 0);
56 irq = 0; /* no interrupt -> use polling */
58 /* Register serial ports with 8250.c */
59 memset(&up, 0, sizeof(struct uart_8250_port));
60 up.port.iotype = UPIO_MEM;
61 up.port.uartclk = IOC3_UARTCLK;
62 up.port.type = PORT_16550A;
64 up.port.flags = (UPF_BOOT_AUTOCONF | UPF_SHARE_IRQ);
65 up.port.dev = &pdev->dev;
66 up.port.membase = membase;
67 up.port.mapbase = r->start;
68 up.port.serial_in = ioc3_serial_in;
69 up.port.serial_out = ioc3_serial_out;
70 line = serial8250_register_8250_port(&up);
74 platform_set_drvdata(pdev, data);
78 static int serial8250_ioc3_remove(struct platform_device *pdev)
80 struct ioc3_8250_data *data = platform_get_drvdata(pdev);
82 serial8250_unregister_port(data->line);
86 static struct platform_driver serial8250_ioc3_driver = {
87 .probe = serial8250_ioc3_probe,
88 .remove = serial8250_ioc3_remove,
90 .name = "ioc3-serial8250",
94 module_platform_driver(serial8250_ioc3_driver);
96 MODULE_AUTHOR("Thomas Bogendoerfer <tbogendoerfer@suse.de>");
97 MODULE_DESCRIPTION("SGI IOC3 8250 UART driver");
98 MODULE_LICENSE("GPL");