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 */
  40 static void *ug_io_base;
  41
  42
  43 static 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
  70 static int ug_is_txfifo_ready(void)
  71 {
  72         return ug_io_transaction(0xc0000000) & 0x04000000;
  73 }
  74
  75 static void ug_raw_putc(char ch)
  76 {
  77         ug_io_transaction(0xb0000000 | (ch << 20));
  78 }
  79
  80 static 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
  93 void 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
 104 static int ug_is_adapter_present(void)
 105 {
 106         if (!ug_io_base)
 107                 return 0;
 108         return ug_io_transaction(0x90000000) == 0x04700000;
 109 }
 110
 111 static 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
 124 err_out:
 125         return NULL;
 126 }
 127
 128 void *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