LXR linux/arch/powerpc/boot/ugecon.c

   1/*
   2 * arch/powerpc/boot/ugecon.c
   3 *
   4 * USB Gecko bootwrapper console.
   5 * Copyright (C) 2008-2009 The GameCube Linux Team
   6 * Copyright (C) 2008,2009 Albert Herranz
   7 *
   8 * This program is free software; you can redistribute it and/or
   9 * modify it under the terms of the GNU General Public License
  10 * as published by the Free Software Foundation; either version 2
  11 * of the License, or (at your option) any later version.
  12 *
  13 */
  14
  15#include <stddef.h>
  16#include "stdio.h"
  17#include "types.h"
  18#include "io.h"
  19#include "ops.h"
  20
  21
  22#define EXI_CLK_32MHZ           5
  23
  24#define EXI_CSR                 0x00
  25#define   EXI_CSR_CLKMASK       (0x7<<4)
  26#define     EXI_CSR_CLK_32MHZ   (EXI_CLK_32MHZ<<4)
  27#define   EXI_CSR_CSMASK        (0x7<<7)
  28#define     EXI_CSR_CS_0        (0x1<<7)  /* Chip Select 001 */
  29
  30#define EXI_CR                  0x0c
  31#define   EXI_CR_TSTART         (1<<0)
  32#define   EXI_CR_WRITE          (1<<2)
  33#define   EXI_CR_READ_WRITE     (2<<2)
  34#define   EXI_CR_TLEN(len)      (((len)-1)<<4)
  35
  36#define EXI_DATA                0x10
  37
  38
  39/* virtual address base for input/output, retrieved from device tree */
  40static void *ug_io_base;
  41
  42
  43static u32 ug_io_transaction(u32 in)
  44{
  45        u32 *csr_reg = ug_io_base + EXI_CSR;
  46        u32 *data_reg = ug_io_base + EXI_DATA;
  47        u32 *cr_reg = ug_io_base + EXI_CR;
  48        u32 csr, data, cr;
  49
  50        /* select */
  51        csr = EXI_CSR_CLK_32MHZ | EXI_CSR_CS_0;
  52        out_be32(csr_reg, csr);
  53
  54        /* read/write */
  55        data = in;
  56        out_be32(data_reg, data);
  57        cr = EXI_CR_TLEN(2) | EXI_CR_READ_WRITE | EXI_CR_TSTART;
  58        out_be32(cr_reg, cr);
  59
  60        while (in_be32(cr_reg) & EXI_CR_TSTART)
  61                barrier();
  62
  63        /* deselect */
  64        out_be32(csr_reg, 0);
  65
  66        data = in_be32(data_reg);
  67        return data;
  68}
  69
  70static int ug_is_txfifo_ready(void)
  71{
  72        return ug_io_transaction(0xc0000000) & 0x04000000;
  73}
  74
  75static void ug_raw_putc(char ch)
  76{
  77        ug_io_transaction(0xb0000000 | (ch << 20));
  78}
  79
  80static void ug_putc(char ch)
  81{
  82        int count = 16;
  83
  84        if (!ug_io_base)
  85                return;
  86
  87        while (!ug_is_txfifo_ready() && count--)
  88                barrier();
  89        if (count >= 0)
  90                ug_raw_putc(ch);
  91}
  92
  93void ug_console_write(const char *buf, int len)
  94{
  95        char *b = (char *)buf;
  96
  97        while (len--) {
  98                if (*b == '\n')
  99                        ug_putc('\r');
 100                ug_putc(*b++);
 101        }
 102}
 103
 104static int ug_is_adapter_present(void)
 105{
 106        if (!ug_io_base)
 107                return 0;
 108        return ug_io_transaction(0x90000000) == 0x04700000;
 109}
 110
 111static void *ug_grab_exi_io_base(void)
 112{
 113        u32 v;
 114        void *devp;
 115
 116        devp = find_node_by_compatible(NULL, "nintendo,flipper-exi");
 117        if (devp == NULL)
 118                goto err_out;
 119        if (getprop(devp, "virtual-reg", &v, sizeof(v)) != sizeof(v))
 120                goto err_out;
 121
 122        return (void *)v;
 123
 124err_out:
 125        return NULL;
 126}
 127
 128void *ug_probe(void)
 129{
 130        void *exi_io_base;
 131        int i;
 132
 133        exi_io_base = ug_grab_exi_io_base();
 134        if (!exi_io_base)
 135                return NULL;
 136
 137        /* look for a usbgecko on memcard slots A and B */
 138        for (i = 0; i < 2; i++) {
 139                ug_io_base = exi_io_base + 0x14 * i;
 140                if (ug_is_adapter_present())
 141                        break;
 142        }
 143        if (i == 2)
 144                ug_io_base = NULL;
 145        return ug_io_base;
 146}
 147
 148