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/*
* 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/slab.h>
#include <linux/delay.h>
#include <linux/serial_core.h>
#include <linux/serial_8250.h>
#include <linux/serial_reg.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/of_platform.h>
#include <linux/nwpserial.h>
#include <linux/clk.h>
struct of_serial_info {
struct clk *clk;
int type;
int line;
};
#ifdef CONFIG_ARCH_TEGRA
void tegra_serial_handle_break(struct uart_port *p)
{
unsigned int status, tmout = 10000;
do {
status = p->serial_in(p, UART_LSR);
if (status & (UART_LSR_FIFOE | UART_LSR_BRK_ERROR_BITS))
status = p->serial_in(p, UART_RX);
else
break;
if (--tmout == 0)
break;
udelay(1);
} while (1);
}
#else
static inline void tegra_serial_handle_break(struct uart_port *port)
{
}
#endif
/*
* Fill a struct uart_port for a given device node
*/
static int of_platform_serial_setup(struct platform_device *ofdev,
int type, struct uart_port *port,
struct of_serial_info *info)
{
struct resource resource;
struct device_node *np = ofdev->dev.of_node;
u32 clk, spd, prop;
int ret;
memset(port, 0, sizeof *port);
if (of_property_read_u32(np, "clock-frequency", &clk)) {
/* Get clk rate through clk driver if present */
info->clk = clk_get(&ofdev->dev, NULL);
if (IS_ERR(info->clk)) {
dev_warn(&ofdev->dev,
"clk or clock-frequency not defined\n");
return PTR_ERR(info->clk);
}
clk_prepare_enable(info->clk);
clk = clk_get_rate(info->clk);
}
/* If current-speed was set, then try not to change it. */
if (of_property_read_u32(np, "current-speed", &spd) == 0)
port->custom_divisor = clk / (16 * spd);
ret = of_address_to_resource(np, 0, &resource);
if (ret) {
dev_warn(&ofdev->dev, "invalid address\n");
goto out;
}
spin_lock_init(&port->lock);
port->mapbase = resource.start;
/* Check for shifted address mapping */
if (of_property_read_u32(np, "reg-offset", &prop) == 0)
port->mapbase += prop;
/* Check for registers offset within the devices address range */
if (of_property_read_u32(np, "reg-shift", &prop) == 0)
port->regshift = prop;
port->irq = irq_of_parse_and_map(np, 0);
port->iotype = UPIO_MEM;
if (of_property_read_u32(np, "reg-io-width", &prop) == 0) {
switch (prop) {
case 1:
port->iotype = UPIO_MEM;
break;
case 4:
port->iotype = UPIO_MEM32;
break;
default:
dev_warn(&ofdev->dev, "unsupported reg-io-width (%d)\n",
prop);
ret = -EINVAL;
goto out;
}
}
port->type = type;
port->uartclk = clk;
port->flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF | UPF_IOREMAP
| UPF_FIXED_PORT | UPF_FIXED_TYPE;
if (of_find_property(np, "no-loopback-test", NULL))
port->flags |= UPF_SKIP_TEST;
port->dev = &ofdev->dev;
if (type == PORT_TEGRA)
port->handle_break = tegra_serial_handle_break;
return 0;
out:
if (info->clk)
clk_disable_unprepare(info->clk);
return ret;
}
/*
* Try to register a serial port
*/
static struct of_device_id of_platform_serial_table[];
static int of_platform_serial_probe(struct platform_device *ofdev)
{
const struct of_device_id *match;
struct of_serial_info *info;
struct uart_port port;
int port_type;
int ret;
match = of_match_device(of_platform_serial_table, &ofdev->dev);
if (!match)
return -EINVAL;
if (of_find_property(ofdev->dev.of_node, "used-by-rtas", NULL))
return -EBUSY;
info = kmalloc(sizeof(*info), GFP_KERNEL);
if (info == NULL)
return -ENOMEM;
port_type = (unsigned long)match->data;
ret = of_platform_serial_setup(ofdev, port_type, &port, info);
if (ret)
goto out;
switch (port_type) {
#ifdef CONFIG_SERIAL_8250
case PORT_8250 ... PORT_MAX_8250:
{
/* For now the of bindings don't support the extra
8250 specific bits */
struct uart_8250_port port8250;
memset(&port8250, 0, sizeof(port8250));
port8250.port = port;
ret = serial8250_register_8250_port(&port8250);
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;
dev_set_drvdata(&ofdev->dev, info);
return 0;
out:
kfree(info);
irq_dispose_mapping(port.irq);
return ret;
}
/*
* Release a line
*/
static int of_platform_serial_remove(struct platform_device *ofdev)
{
struct of_serial_info *info = dev_get_drvdata(&ofdev->dev);
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;
}
if (info->clk)
clk_disable_unprepare(info->clk);
kfree(info);
return 0;
}
/*
* A few common types, add more as needed.
*/
static struct of_device_id of_platform_serial_table[] = {
{ .compatible = "ns8250", .data = (void *)PORT_8250, },
{ .compatible = "ns16450", .data = (void *)PORT_16450, },
{ .compatible = "ns16550a", .data = (void *)PORT_16550A, },
{ .compatible = "ns16550", .data = (void *)PORT_16550, },
{ .compatible = "ns16750", .data = (void *)PORT_16750, },
{ .compatible = "ns16850", .data = (void *)PORT_16850, },
{ .compatible = "nvidia,tegra20-uart", .data = (void *)PORT_TEGRA, },
{ .compatible = "nxp,lpc3220-uart", .data = (void *)PORT_LPC3220, },
#ifdef CONFIG_SERIAL_OF_PLATFORM_NWPSERIAL
{ .compatible = "ibm,qpace-nwp-serial",
.data = (void *)PORT_NWPSERIAL, },
#endif
{ .type = "serial", .data = (void *)PORT_UNKNOWN, },
{ /* end of list */ },
};
static struct platform_driver of_platform_serial_driver = {
.driver = {
.name = "of_serial",
.owner = THIS_MODULE,
.of_match_table = of_platform_serial_table,
},
.probe = of_platform_serial_probe,
.remove = of_platform_serial_remove,
};
module_platform_driver(of_platform_serial_driver);
MODULE_AUTHOR("Arnd Bergmann <arnd@arndb.de>");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Serial Port driver for Open Firmware platform devices");
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