1 | /* |
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2 | * $Id$ |
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3 | */ |
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4 | |
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5 | /*######################################################### |
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6 | # |
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7 | # This code is a modified version of what you will find at the |
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8 | # end of the IDP User's manual. The original code is copyrighted |
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9 | # by Motorola and Motorola Semiconductor Products as well as |
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10 | # Motorola Software products group. |
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11 | # |
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12 | # Modifications to the original IDP code by Doug McBride, Colorado |
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13 | # Space Grant College. Modifications include a means of accessing |
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14 | # port B of the duart as well as port A as well as modifications for |
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15 | # buffering and RTEMS support. Modifications are provided |
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16 | # as is and may not be correct. |
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17 | # |
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18 | # Rob Savoye provided the format for the mc68681 header file |
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19 | # |
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20 | # Joel Sherrill provided inspiration for recoding my original assembly |
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21 | # for this file into C (a good idea) |
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22 | # |
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23 | ##########################################################*/ |
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24 | |
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25 | #include "mc68230.h" |
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26 | #include "mc68681.h" |
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27 | #include "ringbuf.h" |
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28 | #include "rtems.h" |
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29 | #include "bsp.h" |
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30 | |
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31 | rtems_isr C_Receive_ISR(rtems_vector_number vector); |
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32 | extern Ring_buffer_t Buffer[]; |
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33 | |
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34 | extern unsigned char inbuf[]; |
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35 | extern unsigned char inbuf_portb[]; |
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36 | extern unsigned tail; |
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37 | extern unsigned tail_portb; |
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38 | unsigned char Pit_initialized = 0; |
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39 | |
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40 | /*##################################################################### |
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41 | # The volatile routine to initialize the duart -- port a and port b |
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42 | ######################################################################*/ |
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43 | volatile void init_pit() |
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44 | { |
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45 | /* Disable ports A & B while configuring PIT */ |
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46 | MC68681_WRITE(DUART_IMR, 0x00); /* disable imr */ |
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47 | MC68681_WRITE(DUART_CRA, 0x08); /* disable port a transmitter */ |
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48 | MC68681_WRITE(DUART_CRA, 0x02); /* disable port a receiver */ |
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49 | MC68681_WRITE(DUART_CRB, 0x08); /* disable port b transmitter */ |
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50 | MC68681_WRITE(DUART_CRB, 0x02); /* disable port b receiver */ |
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51 | |
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52 | /* install ISR for ports A and B */ |
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53 | set_vector(C_Receive_ISR, (VECT+H3VECT), 1); |
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54 | |
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55 | /* initialize pit */ |
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56 | MC68230_WRITE(PGCR, 0x00); /* set mode to 0 -- disable all ports */ |
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57 | MC68230_WRITE(PSRR, 0x18); /* set up pirq and piack */ |
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58 | MC68230_WRITE(PBDDR, 0x00); /* all pins on port b are input */ |
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59 | MC68230_WRITE(PBCR, 0x82); /* submode 1x, h3 interrupt enabled */ |
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60 | MC68230_WRITE(PIVR, VECT); /* setup pivr */ |
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61 | MC68230_WRITE(PGCR, 0x20); /* turn on all ports */ |
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62 | |
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63 | /* For some reason, the reset of receiver/transmitter only works for |
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64 | the first time around -- it garbles the output otherwise (e.g., sp21) */ |
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65 | if (!Pit_initialized) |
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66 | { |
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67 | /* now initialize the duart registers on port b */ |
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68 | /* WARNING:OPTIMIZER MAY ONLY EXECUTE THIRD STATEMENT IF NOT VOLATILE */ |
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69 | MC68681_WRITE(DUART_CRB, 0x30); /* reset tx, channel b */ |
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70 | MC68681_WRITE(DUART_CRB, 0x20); /* reset rx, channel b */ |
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71 | MC68681_WRITE(DUART_CRB, 0x10); /* reset mr pointer, channel b */ |
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72 | |
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73 | /* now initialize the duart registers on port a */ |
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74 | /* WARNING:OPTIMIZER MAY ONLY EXECUTE THIRD STATEMENT IF NOT VOLATILE */ |
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75 | MC68681_WRITE(DUART_CRA, 0x30); /* reset tx, channel a */ |
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76 | MC68681_WRITE(DUART_CRA, 0x20); /* reset rx, channel a */ |
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77 | MC68681_WRITE(DUART_CRA, 0x10); /* reset mr pointer, channel a */ |
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78 | Pit_initialized = 1; |
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79 | } |
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80 | |
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81 | /* init the general registers of the duart */ |
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82 | MC68681_WRITE(DUART_IVR, 0x0f); /* init ivr */ |
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83 | MC68681_WRITE(DUART_IMR, 0x22); /* init imr */ |
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84 | MC68681_WRITE(DUART_ACR, 0x00); /* init acr */ |
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85 | MC68681_WRITE(DUART_CTUR, 0x00); /* init ctur */ |
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86 | MC68681_WRITE(DUART_CTLR, 0x02); /* init ctlr */ |
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87 | MC68681_WRITE(DUART_OPCR, 0x00); /* init opcr */ |
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88 | MC68681_WRITE(DUART_OPRSET, 0x01); /* init cts */ |
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89 | |
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90 | /* init the actual serial port for port a */ |
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91 | MC68681_WRITE(DUART_CSRA, 0xbb); /* init csra -- 9600 baud */ |
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92 | MC68681_WRITE(DUART_MR1A, 0x13); /* init mr1a */ |
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93 | MC68681_WRITE(DUART_MR2A, 0x07); /* init mr2a */ |
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94 | MC68681_WRITE(DUART_CRA, 0x05); /* init cra */ |
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95 | |
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96 | /* init the actual serial port for port b */ |
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97 | MC68681_WRITE(DUART_CSRB, 0xbb); /* init csrb -- 9600 baud */ |
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98 | #define EIGHT_BITS_NO_PARITY |
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99 | #ifdef EIGHT_BITS_NO_PARITY |
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100 | MC68681_WRITE(DUART_MR1B, 0x13); /* init mr1b */ |
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101 | #else /* 7 bits, even parity */ |
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102 | MC68681_WRITE(DUART_MR1B, 0x02); /* init mr1b */ |
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103 | #endif |
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104 | MC68681_WRITE(DUART_MR2B, 0x07); /* init mr2b -- one stop bit */ |
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105 | MC68681_WRITE(DUART_CRB, 0x05); /* init crb */ |
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106 | } |
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107 | |
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108 | /*##################################################################### |
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109 | # interrupt handler for receive of character from duart on ports A & B |
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110 | #####################################################################*/ |
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111 | rtems_isr C_Receive_ISR(rtems_vector_number vector) |
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112 | { |
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113 | volatile unsigned char *_addr; |
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114 | |
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115 | _addr = (unsigned char *) (PIT_ADDR + PITSR); |
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116 | *_addr = 0x04; /* clear pit interrupt */ |
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117 | |
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118 | /* Let's check port A first for input */ |
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119 | _addr = (unsigned char *) (DUART_ADDR + DUART_SRA); |
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120 | if (*_addr & 0x01) /* extract rcvrdy on port A */ |
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121 | { |
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122 | /* Read input on port A */ |
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123 | _addr = (unsigned char *) (DUART_ADDR + DUART_RBA); |
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124 | Ring_buffer_Add_character( &Buffer[ 0 ], *_addr ); |
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125 | } |
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126 | else /* If not on port A, let's check port B */ |
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127 | { |
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128 | _addr = (unsigned char *) (DUART_ADDR + DUART_SRB); |
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129 | if (*_addr & 0x01) /* extract rcvrdy on port B */ |
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130 | { |
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131 | /* Read input on port B */ |
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132 | _addr = (unsigned char *) (DUART_ADDR + DUART_RBB); |
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133 | Ring_buffer_Add_character( &Buffer[ 1 ], *_addr ); |
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134 | } |
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135 | /* if not ready on port A or port B, must be an error */ |
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136 | /* if error, get out so that fifo is undisturbed */ |
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137 | } |
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138 | } |
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139 | |
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140 | /*##################################################################### |
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141 | # This is the routine that actually transmits a character one at a time |
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142 | # This routine transmits on port A of the IDP board |
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143 | #####################################################################*/ |
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144 | void transmit_char(char ch) |
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145 | { |
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146 | volatile unsigned char *_addr; |
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147 | |
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148 | /* Get SRA (extract txrdy) */ |
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149 | _addr = (unsigned char *) (DUART_ADDR + DUART_SRA); |
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150 | while (!(*_addr & 0x04)) |
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151 | { |
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152 | } |
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153 | |
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154 | /* transmit character over port A */ |
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155 | MC68681_WRITE(DUART_TBA, ch); |
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156 | } |
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157 | |
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158 | /*##################################################################### |
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159 | # This is the routine that actually transmits a character one at a time |
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160 | # This routine transmits on port B of the IDP board |
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161 | #####################################################################*/ |
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162 | void transmit_char_portb(char ch) |
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163 | { |
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164 | volatile unsigned char *_addr; |
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165 | |
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166 | /* Get SRB (extract txrdy) */ |
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167 | _addr = (unsigned char *) (DUART_ADDR + DUART_SRB); |
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168 | while (!(*_addr & 0x04)) |
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169 | { |
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170 | } |
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171 | |
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172 | /* transmit character over port B */ |
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173 | MC68681_WRITE(DUART_TBB, ch); |
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174 | } |
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