// SPDX-License-Identifier: GPL-2.0 /* * SGI IOC3 8250 UART driver * * Copyright (C) 2019 Thomas Bogendoerfer <tbogendoerfer@suse.de> * * based on code Copyright (C) 2005 Stanislaw Skowronek <skylark@unaligned.org> * Copyright (C) 2014 Joshua Kinard <kumba@gentoo.org> */ #include <linux/module.h> #include <linux/errno.h> #include <linux/io.h> #include <linux/platform_device.h> #include "8250.h" #define IOC3_UARTCLK (22000000 / 3) struct ioc3_8250_data { int line; }; static unsigned int ioc3_serial_in(struct uart_port *p, int offset) { return readb(p->membase + (offset ^ 3)); } static void ioc3_serial_out(struct uart_port *p, int offset, int value) { writeb(value, p->membase + (offset ^ 3)); } static int serial8250_ioc3_probe(struct platform_device *pdev) { struct ioc3_8250_data *data; struct uart_8250_port up; struct resource *r; void __iomem *membase; int irq, line; r = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (!r) return -ENODEV; data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); if (!data) return -ENOMEM; membase = devm_ioremap(&pdev->dev, r->start, resource_size(r)); if (!membase) return -ENOMEM; irq = platform_get_irq(pdev, 0); if (irq < 0) irq = 0; /* no interrupt -> use polling */ /* Register serial ports with 8250.c */ memset(&up, 0, sizeof(struct uart_8250_port)); up.port.iotype = UPIO_MEM; up.port.uartclk = IOC3_UARTCLK; up.port.type = PORT_16550A; up.port.irq = irq; up.port.flags = (UPF_BOOT_AUTOCONF | UPF_SHARE_IRQ); up.port.dev = &pdev->dev; up.port.membase = membase; up.port.mapbase = r->start; up.port.serial_in = ioc3_serial_in; up.port.serial_out = ioc3_serial_out; line = serial8250_register_8250_port(&up); if (line < 0) return line; platform_set_drvdata(pdev, data); return 0; } static int serial8250_ioc3_remove(struct platform_device *pdev) { struct ioc3_8250_data *data = platform_get_drvdata(pdev); serial8250_unregister_port(data->line); return 0; } static struct platform_driver serial8250_ioc3_driver = { .probe = serial8250_ioc3_probe, .remove = serial8250_ioc3_remove, .driver = { .name = "ioc3-serial8250", } }; module_platform_driver(serial8250_ioc3_driver); MODULE_AUTHOR("Thomas Bogendoerfer <tbogendoerfer@suse.de>"); MODULE_DESCRIPTION("SGI IOC3 8250 UART driver"); MODULE_LICENSE("GPL");