android_kernel_xiaomi_sm8350/drivers/serial/of_serial.c
Matthias Fuchs 0025e75357 serial: Add 16850 uart type support to OF uart driver
This patch adds support for "ns16850" as supported value
of the compatible node in flat device tree uart descriptions.

This is needed for example when you have a XR16C2850 uart
connected to a PPC405's external bus controller.

Signed-off-by: Matthias Fuchs <mfuchs@ma-fu.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-01-16 16:15:17 +11:00

198 lines
5.0 KiB
C

/*
* Serial Port driver for Open Firmware platform devices
*
* Copyright (C) 2006 Arnd Bergmann <arnd@arndb.de>, IBM Corp.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/serial_core.h>
#include <linux/serial_8250.h>
#include <linux/of_platform.h>
#include <linux/nwpserial.h>
#include <asm/prom.h>
struct of_serial_info {
int type;
int line;
};
/*
* Fill a struct uart_port for a given device node
*/
static int __devinit of_platform_serial_setup(struct of_device *ofdev,
int type, struct uart_port *port)
{
struct resource resource;
struct device_node *np = ofdev->node;
const unsigned int *clk, *spd;
const u32 *prop;
int ret, prop_size;
memset(port, 0, sizeof *port);
spd = of_get_property(np, "current-speed", NULL);
clk = of_get_property(np, "clock-frequency", NULL);
if (!clk) {
dev_warn(&ofdev->dev, "no clock-frequency property set\n");
return -ENODEV;
}
ret = of_address_to_resource(np, 0, &resource);
if (ret) {
dev_warn(&ofdev->dev, "invalid address\n");
return ret;
}
spin_lock_init(&port->lock);
port->mapbase = resource.start;
/* Check for shifted address mapping */
prop = of_get_property(np, "reg-offset", &prop_size);
if (prop && (prop_size == sizeof(u32)))
port->mapbase += *prop;
/* Check for registers offset within the devices address range */
prop = of_get_property(np, "reg-shift", &prop_size);
if (prop && (prop_size == sizeof(u32)))
port->regshift = *prop;
port->irq = irq_of_parse_and_map(np, 0);
port->iotype = UPIO_MEM;
port->type = type;
port->uartclk = *clk;
port->flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF | UPF_IOREMAP
| UPF_FIXED_PORT;
port->dev = &ofdev->dev;
/* If current-speed was set, then try not to change it. */
if (spd)
port->custom_divisor = *clk / (16 * (*spd));
return 0;
}
/*
* Try to register a serial port
*/
static int __devinit of_platform_serial_probe(struct of_device *ofdev,
const struct of_device_id *id)
{
struct of_serial_info *info;
struct uart_port port;
int port_type;
int ret;
if (of_find_property(ofdev->node, "used-by-rtas", NULL))
return -EBUSY;
info = kmalloc(sizeof(*info), GFP_KERNEL);
if (info == NULL)
return -ENOMEM;
port_type = (unsigned long)id->data;
ret = of_platform_serial_setup(ofdev, port_type, &port);
if (ret)
goto out;
switch (port_type) {
#ifdef CONFIG_SERIAL_8250
case PORT_8250 ... PORT_MAX_8250:
ret = serial8250_register_port(&port);
break;
#endif
#ifdef CONFIG_SERIAL_OF_PLATFORM_NWPSERIAL
case PORT_NWPSERIAL:
ret = nwpserial_register_port(&port);
break;
#endif
default:
/* need to add code for these */
case PORT_UNKNOWN:
dev_info(&ofdev->dev, "Unknown serial port found, ignored\n");
ret = -ENODEV;
break;
}
if (ret < 0)
goto out;
info->type = port_type;
info->line = ret;
ofdev->dev.driver_data = info;
return 0;
out:
kfree(info);
irq_dispose_mapping(port.irq);
return ret;
}
/*
* Release a line
*/
static int of_platform_serial_remove(struct of_device *ofdev)
{
struct of_serial_info *info = ofdev->dev.driver_data;
switch (info->type) {
#ifdef CONFIG_SERIAL_8250
case PORT_8250 ... PORT_MAX_8250:
serial8250_unregister_port(info->line);
break;
#endif
#ifdef CONFIG_SERIAL_OF_PLATFORM_NWPSERIAL
case PORT_NWPSERIAL:
nwpserial_unregister_port(info->line);
break;
#endif
default:
/* need to add code for these */
break;
}
kfree(info);
return 0;
}
/*
* A few common types, add more as needed.
*/
static struct of_device_id __devinitdata of_platform_serial_table[] = {
{ .type = "serial", .compatible = "ns8250", .data = (void *)PORT_8250, },
{ .type = "serial", .compatible = "ns16450", .data = (void *)PORT_16450, },
{ .type = "serial", .compatible = "ns16550", .data = (void *)PORT_16550, },
{ .type = "serial", .compatible = "ns16750", .data = (void *)PORT_16750, },
{ .type = "serial", .compatible = "ns16850", .data = (void *)PORT_16850, },
#ifdef CONFIG_SERIAL_OF_PLATFORM_NWPSERIAL
{ .type = "serial", .compatible = "ibm,qpace-nwp-serial",
.data = (void *)PORT_NWPSERIAL, },
#endif
{ .type = "serial", .data = (void *)PORT_UNKNOWN, },
{ /* end of list */ },
};
static struct of_platform_driver of_platform_serial_driver = {
.owner = THIS_MODULE,
.name = "of_serial",
.probe = of_platform_serial_probe,
.remove = of_platform_serial_remove,
.match_table = of_platform_serial_table,
};
static int __init of_platform_serial_init(void)
{
return of_register_platform_driver(&of_platform_serial_driver);
}
module_init(of_platform_serial_init);
static void __exit of_platform_serial_exit(void)
{
return of_unregister_platform_driver(&of_platform_serial_driver);
};
module_exit(of_platform_serial_exit);
MODULE_AUTHOR("Arnd Bergmann <arnd@arndb.de>");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Serial Port driver for Open Firmware platform devices");