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1// SPDX-License-Identifier: GPL-2.02/*3 * SGI IOC3 8250 UART driver4 *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 void 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}84 85static struct platform_driver serial8250_ioc3_driver = {86 .probe = serial8250_ioc3_probe,87 .remove_new = serial8250_ioc3_remove,88 .driver = {89 .name = "ioc3-serial8250",90 }91};92 93module_platform_driver(serial8250_ioc3_driver);94 95MODULE_AUTHOR("Thomas Bogendoerfer <tbogendoerfer@suse.de>");96MODULE_DESCRIPTION("SGI IOC3 8250 UART driver");97MODULE_LICENSE("GPL");98