linuxdebug/drivers/tty/serial/8250/8250_ioc3.c

99 lines
2.3 KiB
C

// 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");