cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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8250_ioc3.c (2359B)

      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * SGI IOC3 8250 UART driver
      4 *
      5 * Copyright (C) 2019 Thomas Bogendoerfer <tbogendoerfer@suse.de>
      6 *
      7 * based on code Copyright (C) 2005 Stanislaw Skowronek <skylark@unaligned.org>
      8 *               Copyright (C) 2014 Joshua Kinard <kumba@gentoo.org>
      9 */
     10
     11#include <linux/module.h>
     12#include <linux/errno.h>
     13#include <linux/io.h>
     14#include <linux/platform_device.h>
     15
     16#include "8250.h"
     17
     18#define IOC3_UARTCLK (22000000 / 3)
     19
     20struct ioc3_8250_data {
     21	int line;
     22};
     23
     24static unsigned int ioc3_serial_in(struct uart_port *p, int offset)
     25{
     26	return readb(p->membase + (offset ^ 3));
     27}
     28
     29static void ioc3_serial_out(struct uart_port *p, int offset, int value)
     30{
     31	writeb(value, p->membase + (offset ^ 3));
     32}
     33
     34static int serial8250_ioc3_probe(struct platform_device *pdev)
     35{
     36	struct ioc3_8250_data *data;
     37	struct uart_8250_port up;
     38	struct resource *r;
     39	void __iomem *membase;
     40	int irq, line;
     41
     42	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
     43	if (!r)
     44		return -ENODEV;
     45
     46	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
     47	if (!data)
     48		return -ENOMEM;
     49
     50	membase = devm_ioremap(&pdev->dev, r->start, resource_size(r));
     51	if (!membase)
     52		return -ENOMEM;
     53
     54	irq = platform_get_irq(pdev, 0);
     55	if (irq < 0)
     56		irq = 0; /* no interrupt -> use polling */
     57
     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;
     63	up.port.irq = irq;
     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);
     71	if (line < 0)
     72		return line;
     73
     74	platform_set_drvdata(pdev, data);
     75	return 0;
     76}
     77
     78static int serial8250_ioc3_remove(struct platform_device *pdev)
     79{
     80	struct ioc3_8250_data *data = platform_get_drvdata(pdev);
     81
     82	serial8250_unregister_port(data->line);
     83	return 0;
     84}
     85
     86static struct platform_driver serial8250_ioc3_driver = {
     87	.probe  = serial8250_ioc3_probe,
     88	.remove = serial8250_ioc3_remove,
     89	.driver = {
     90		.name = "ioc3-serial8250",
     91	}
     92};
     93
     94module_platform_driver(serial8250_ioc3_driver);
     95
     96MODULE_AUTHOR("Thomas Bogendoerfer <tbogendoerfer@suse.de>");
     97MODULE_DESCRIPTION("SGI IOC3 8250 UART driver");
     98MODULE_LICENSE("GPL");