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/* SPDX-License-Identifier: GPL-2.0-only WITH eCos-exception-2.0 */
/*
* Copyright (C) 2004-2007 ARM Limited.
* Copyright (C) 2008 Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
*/
#include <common.h>
#include <driver.h>
#include <init.h>
#if defined(CONFIG_CPU_V6)
/*
* ARMV6
*/
#define DCC_RBIT (1 << 30)
#define DCC_WBIT (1 << 29)
#define write_dcc(x) \
__asm__ volatile ("mcr p14, 0, %0, c0, c5, 0\n" : : "r" (x))
#define read_dcc(x) \
__asm__ volatile ("mrc p14, 0, %0, c0, c5, 0\n" : "=r" (x))
#define status_dcc(x) \
__asm__ volatile ("mrc p14, 0, %0, c0, c1, 0\n" : "=r" (x))
#elif defined(CONFIG_CPU_XSCALE)
/*
* XSCALE
*/
#define DCC_RBIT (1 << 31)
#define DCC_WBIT (1 << 28)
#define write_dcc(x) \
__asm__ volatile ("mcr p14, 0, %0, c8, c0, 0\n" : : "r" (x))
#define read_dcc(x) \
__asm__ volatile ("mrc p14, 0, %0, c9, c0, 0\n" : "=r" (x))
#define status_dcc(x) \
__asm__ volatile ("mrc p14, 0, %0, c14, c0, 0\n" : "=r" (x))
#else
#define DCC_RBIT (1 << 0)
#define DCC_WBIT (1 << 1)
#define write_dcc(x) \
__asm__ volatile ("mcr p14, 0, %0, c1, c0, 0\n" : : "r" (x))
#define read_dcc(x) \
__asm__ volatile ("mrc p14, 0, %0, c1, c0, 0\n" : "=r" (x))
#define status_dcc(x) \
__asm__ volatile ("mrc p14, 0, %0, c0, c0, 0\n" : "=r" (x))
#endif
#define can_read_dcc(x) do { \
status_dcc(x); \
x &= DCC_RBIT; \
} while (0);
#define can_write_dcc(x) do { \
status_dcc(x); \
x &= DCC_WBIT; \
x = (x == 0); \
} while (0);
#define TIMEOUT_COUNT 0x4000000
static int arm_dcc_getc(struct console_device *cdev)
{
int c;
register unsigned int reg;
do {
can_read_dcc(reg);
} while (!reg);
read_dcc(c);
return c;
}
static void arm_dcc_putc(struct console_device *cdev, char c)
{
register unsigned int reg;
unsigned int timeout_count = TIMEOUT_COUNT;
while (--timeout_count) {
can_write_dcc(reg);
if (reg)
break;
}
if (timeout_count == 0)
return;
else
write_dcc(c);
}
static int arm_dcc_tstc(struct console_device *cdev)
{
register unsigned int reg;
can_read_dcc(reg);
return reg;
}
static struct console_device arm_dcc_dev;
static int arm_dcc_probe(struct device *dev)
{
struct console_device *cdev;
cdev = &arm_dcc_dev;
cdev->dev = dev;
cdev->tstc = arm_dcc_tstc;
cdev->putc = arm_dcc_putc;
cdev->getc = arm_dcc_getc;
/* Enable UART */
console_register(cdev);
return 0;
}
static struct driver arm_dcc_driver = {
.name = "arm_dcc",
.probe = arm_dcc_probe,
};
console_platform_driver(arm_dcc_driver);
static struct device arm_dcc_device = {
.id = DEVICE_ID_DYNAMIC,
.name = "arm_dcc",
};
static int arm_dcc_init(void)
{
return platform_device_register(&arm_dcc_device);
}
console_initcall(arm_dcc_init);
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