linux/arch/mips/cavium-octeon/serial.c

110 lines
2.6 KiB
C

/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 2004-2007 Cavium Networks
*/
#include <linux/console.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/serial.h>
#include <linux/serial_8250.h>
#include <linux/serial_reg.h>
#include <linux/tty.h>
#include <linux/irq.h>
#include <asm/time.h>
#include <asm/octeon/octeon.h>
#define DEBUG_UART 1
unsigned int octeon_serial_in(struct uart_port *up, int offset)
{
int rv = cvmx_read_csr((uint64_t)(up->membase + (offset << 3)));
if (offset == UART_IIR && (rv & 0xf) == 7) {
/* Busy interrupt, read the USR (39) and try again. */
cvmx_read_csr((uint64_t)(up->membase + (39 << 3)));
rv = cvmx_read_csr((uint64_t)(up->membase + (offset << 3)));
}
return rv;
}
void octeon_serial_out(struct uart_port *up, int offset, int value)
{
/*
* If bits 6 or 7 of the OCTEON UART's LCR are set, it quits
* working.
*/
if (offset == UART_LCR)
value &= 0x9f;
cvmx_write_csr((uint64_t)(up->membase + (offset << 3)), (u8)value);
}
static int __devinit octeon_serial_probe(struct platform_device *pdev)
{
int irq, res;
struct resource *res_mem;
struct uart_port port;
/* All adaptors have an irq. */
irq = platform_get_irq(pdev, 0);
if (irq < 0)
return irq;
memset(&port, 0, sizeof(port));
port.flags = ASYNC_SKIP_TEST | UPF_SHARE_IRQ | UPF_FIXED_TYPE;
port.type = PORT_OCTEON;
port.iotype = UPIO_MEM;
port.regshift = 3;
port.dev = &pdev->dev;
if (octeon_is_simulation())
/* Make simulator output fast*/
port.uartclk = 115200 * 16;
else
port.uartclk = octeon_get_io_clock_rate();
port.serial_in = octeon_serial_in;
port.serial_out = octeon_serial_out;
port.irq = irq;
res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (res_mem == NULL) {
dev_err(&pdev->dev, "found no memory resource\n");
return -ENXIO;
}
port.mapbase = res_mem->start;
port.membase = ioremap(res_mem->start, resource_size(res_mem));
res = serial8250_register_port(&port);
return res >= 0 ? 0 : res;
}
static struct of_device_id octeon_serial_match[] = {
{
.compatible = "cavium,octeon-3860-uart",
},
{},
};
MODULE_DEVICE_TABLE(of, octeon_serial_match);
static struct platform_driver octeon_serial_driver = {
.probe = octeon_serial_probe,
.driver = {
.owner = THIS_MODULE,
.name = "octeon_serial",
.of_match_table = octeon_serial_match,
},
};
static int __init octeon_serial_init(void)
{
return platform_driver_register(&octeon_serial_driver);
}
late_initcall(octeon_serial_init);