cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

ugecon.c (2698B)

      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*
      3 * arch/powerpc/boot/ugecon.c
      4 *
      5 * USB Gecko bootwrapper console.
      6 * Copyright (C) 2008-2009 The GameCube Linux Team
      7 * Copyright (C) 2008,2009 Albert Herranz
      8 */
      9
     10#include <stddef.h>
     11#include "stdio.h"
     12#include "types.h"
     13#include "io.h"
     14#include "ops.h"
     15
     16
     17#define EXI_CLK_32MHZ           5
     18
     19#define EXI_CSR                 0x00
     20#define   EXI_CSR_CLKMASK       (0x7<<4)
     21#define     EXI_CSR_CLK_32MHZ   (EXI_CLK_32MHZ<<4)
     22#define   EXI_CSR_CSMASK        (0x7<<7)
     23#define     EXI_CSR_CS_0        (0x1<<7)  /* Chip Select 001 */
     24
     25#define EXI_CR                  0x0c
     26#define   EXI_CR_TSTART         (1<<0)
     27#define   EXI_CR_WRITE		(1<<2)
     28#define   EXI_CR_READ_WRITE     (2<<2)
     29#define   EXI_CR_TLEN(len)      (((len)-1)<<4)
     30
     31#define EXI_DATA                0x10
     32
     33
     34/* virtual address base for input/output, retrieved from device tree */
     35static void *ug_io_base;
     36
     37
     38static u32 ug_io_transaction(u32 in)
     39{
     40	u32 *csr_reg = ug_io_base + EXI_CSR;
     41	u32 *data_reg = ug_io_base + EXI_DATA;
     42	u32 *cr_reg = ug_io_base + EXI_CR;
     43	u32 csr, data, cr;
     44
     45	/* select */
     46	csr = EXI_CSR_CLK_32MHZ | EXI_CSR_CS_0;
     47	out_be32(csr_reg, csr);
     48
     49	/* read/write */
     50	data = in;
     51	out_be32(data_reg, data);
     52	cr = EXI_CR_TLEN(2) | EXI_CR_READ_WRITE | EXI_CR_TSTART;
     53	out_be32(cr_reg, cr);
     54
     55	while (in_be32(cr_reg) & EXI_CR_TSTART)
     56		barrier();
     57
     58	/* deselect */
     59	out_be32(csr_reg, 0);
     60
     61	data = in_be32(data_reg);
     62	return data;
     63}
     64
     65static int ug_is_txfifo_ready(void)
     66{
     67	return ug_io_transaction(0xc0000000) & 0x04000000;
     68}
     69
     70static void ug_raw_putc(char ch)
     71{
     72	ug_io_transaction(0xb0000000 | (ch << 20));
     73}
     74
     75static void ug_putc(char ch)
     76{
     77	int count = 16;
     78
     79	if (!ug_io_base)
     80		return;
     81
     82	while (!ug_is_txfifo_ready() && count--)
     83		barrier();
     84	if (count >= 0)
     85		ug_raw_putc(ch);
     86}
     87
     88void ug_console_write(const char *buf, int len)
     89{
     90	char *b = (char *)buf;
     91
     92	while (len--) {
     93		if (*b == '\n')
     94			ug_putc('\r');
     95		ug_putc(*b++);
     96	}
     97}
     98
     99static int ug_is_adapter_present(void)
    100{
    101	if (!ug_io_base)
    102		return 0;
    103	return ug_io_transaction(0x90000000) == 0x04700000;
    104}
    105
    106static void *ug_grab_exi_io_base(void)
    107{
    108	u32 v;
    109	void *devp;
    110
    111	devp = find_node_by_compatible(NULL, "nintendo,flipper-exi");
    112	if (devp == NULL)
    113		goto err_out;
    114	if (getprop(devp, "virtual-reg", &v, sizeof(v)) != sizeof(v))
    115		goto err_out;
    116
    117	return (void *)v;
    118
    119err_out:
    120	return NULL;
    121}
    122
    123void *ug_probe(void)
    124{
    125	void *exi_io_base;
    126	int i;
    127
    128	exi_io_base = ug_grab_exi_io_base();
    129	if (!exi_io_base)
    130		return NULL;
    131
    132	/* look for a usbgecko on memcard slots A and B */
    133	for (i = 0; i < 2; i++) {
    134		ug_io_base = exi_io_base + 0x14 * i;
    135		if (ug_is_adapter_present())
    136			break;
    137	}
    138	if (i == 2)
    139		ug_io_base = NULL;
    140	return ug_io_base;
    141}
    142