linux/linux-5.18.11/arch/powerpc/boot/ugecon.c

143 lines
2.6 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* arch/powerpc/boot/ugecon.c
*
* USB Gecko bootwrapper console.
* Copyright (C) 2008-2009 The GameCube Linux Team
* Copyright (C) 2008,2009 Albert Herranz
*/
#include <stddef.h>
#include "stdio.h"
#include "types.h"
#include "io.h"
#include "ops.h"
#define EXI_CLK_32MHZ 5
#define EXI_CSR 0x00
#define EXI_CSR_CLKMASK (0x7<<4)
#define EXI_CSR_CLK_32MHZ (EXI_CLK_32MHZ<<4)
#define EXI_CSR_CSMASK (0x7<<7)
#define EXI_CSR_CS_0 (0x1<<7) /* Chip Select 001 */
#define EXI_CR 0x0c
#define EXI_CR_TSTART (1<<0)
#define EXI_CR_WRITE (1<<2)
#define EXI_CR_READ_WRITE (2<<2)
#define EXI_CR_TLEN(len) (((len)-1)<<4)
#define EXI_DATA 0x10
/* virtual address base for input/output, retrieved from device tree */
static void *ug_io_base;
static u32 ug_io_transaction(u32 in)
{
u32 *csr_reg = ug_io_base + EXI_CSR;
u32 *data_reg = ug_io_base + EXI_DATA;
u32 *cr_reg = ug_io_base + EXI_CR;
u32 csr, data, cr;
/* select */
csr = EXI_CSR_CLK_32MHZ | EXI_CSR_CS_0;
out_be32(csr_reg, csr);
/* read/write */
data = in;
out_be32(data_reg, data);
cr = EXI_CR_TLEN(2) | EXI_CR_READ_WRITE | EXI_CR_TSTART;
out_be32(cr_reg, cr);
while (in_be32(cr_reg) & EXI_CR_TSTART)
barrier();
/* deselect */
out_be32(csr_reg, 0);
data = in_be32(data_reg);
return data;
}
static int ug_is_txfifo_ready(void)
{
return ug_io_transaction(0xc0000000) & 0x04000000;
}
static void ug_raw_putc(char ch)
{
ug_io_transaction(0xb0000000 | (ch << 20));
}
static void ug_putc(char ch)
{
int count = 16;
if (!ug_io_base)
return;
while (!ug_is_txfifo_ready() && count--)
barrier();
if (count >= 0)
ug_raw_putc(ch);
}
void ug_console_write(const char *buf, int len)
{
char *b = (char *)buf;
while (len--) {
if (*b == '\n')
ug_putc('\r');
ug_putc(*b++);
}
}
static int ug_is_adapter_present(void)
{
if (!ug_io_base)
return 0;
return ug_io_transaction(0x90000000) == 0x04700000;
}
static void *ug_grab_exi_io_base(void)
{
u32 v;
void *devp;
devp = find_node_by_compatible(NULL, "nintendo,flipper-exi");
if (devp == NULL)
goto err_out;
if (getprop(devp, "virtual-reg", &v, sizeof(v)) != sizeof(v))
goto err_out;
return (void *)v;
err_out:
return NULL;
}
void *ug_probe(void)
{
void *exi_io_base;
int i;
exi_io_base = ug_grab_exi_io_base();
if (!exi_io_base)
return NULL;
/* look for a usbgecko on memcard slots A and B */
for (i = 0; i < 2; i++) {
ug_io_base = exi_io_base + 0x14 * i;
if (ug_is_adapter_present())
break;
}
if (i == 2)
ug_io_base = NULL;
return ug_io_base;
}