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1 /* |
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2 * QEMU 16550A UART emulation |
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3 * |
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4 * Copyright (c) 2003-2004 Fabrice Bellard |
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5 * Copyright (c) 2008 Citrix Systems, Inc. |
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6 * |
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7 * Permission is hereby granted, free of charge, to any person obtaining a copy |
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8 * of this software and associated documentation files (the "Software"), to deal |
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9 * in the Software without restriction, including without limitation the rights |
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10 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
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11 * copies of the Software, and to permit persons to whom the Software is |
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12 * furnished to do so, subject to the following conditions: |
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13 * |
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14 * The above copyright notice and this permission notice shall be included in |
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15 * all copies or substantial portions of the Software. |
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16 * |
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17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
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18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
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19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
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20 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
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21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
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22 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
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23 * THE SOFTWARE. |
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24 */ |
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25 #include "hw.h" |
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26 #include "qemu-char.h" |
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27 #include "isa.h" |
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28 #include "pc.h" |
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29 #include "qemu-timer.h" |
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30 |
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31 //#define DEBUG_SERIAL |
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32 |
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33 #define UART_LCR_DLAB 0x80 /* Divisor latch access bit */ |
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34 |
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35 #define UART_IER_MSI 0x08 /* Enable Modem status interrupt */ |
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36 #define UART_IER_RLSI 0x04 /* Enable receiver line status interrupt */ |
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37 #define UART_IER_THRI 0x02 /* Enable Transmitter holding register int. */ |
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38 #define UART_IER_RDI 0x01 /* Enable receiver data interrupt */ |
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39 |
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40 #define UART_IIR_NO_INT 0x01 /* No interrupts pending */ |
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41 #define UART_IIR_ID 0x06 /* Mask for the interrupt ID */ |
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42 |
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43 #define UART_IIR_MSI 0x00 /* Modem status interrupt */ |
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44 #define UART_IIR_THRI 0x02 /* Transmitter holding register empty */ |
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45 #define UART_IIR_RDI 0x04 /* Receiver data interrupt */ |
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46 #define UART_IIR_RLSI 0x06 /* Receiver line status interrupt */ |
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47 #define UART_IIR_CTI 0x0C /* Character Timeout Indication */ |
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48 |
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49 #define UART_IIR_FENF 0x80 /* Fifo enabled, but not functionning */ |
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50 #define UART_IIR_FE 0xC0 /* Fifo enabled */ |
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51 |
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52 /* |
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53 * These are the definitions for the Modem Control Register |
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54 */ |
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55 #define UART_MCR_LOOP 0x10 /* Enable loopback test mode */ |
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56 #define UART_MCR_OUT2 0x08 /* Out2 complement */ |
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57 #define UART_MCR_OUT1 0x04 /* Out1 complement */ |
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58 #define UART_MCR_RTS 0x02 /* RTS complement */ |
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59 #define UART_MCR_DTR 0x01 /* DTR complement */ |
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60 |
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61 /* |
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62 * These are the definitions for the Modem Status Register |
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63 */ |
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64 #define UART_MSR_DCD 0x80 /* Data Carrier Detect */ |
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65 #define UART_MSR_RI 0x40 /* Ring Indicator */ |
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66 #define UART_MSR_DSR 0x20 /* Data Set Ready */ |
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67 #define UART_MSR_CTS 0x10 /* Clear to Send */ |
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68 #define UART_MSR_DDCD 0x08 /* Delta DCD */ |
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69 #define UART_MSR_TERI 0x04 /* Trailing edge ring indicator */ |
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70 #define UART_MSR_DDSR 0x02 /* Delta DSR */ |
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71 #define UART_MSR_DCTS 0x01 /* Delta CTS */ |
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72 #define UART_MSR_ANY_DELTA 0x0F /* Any of the delta bits! */ |
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73 |
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74 #define UART_LSR_TEMT 0x40 /* Transmitter empty */ |
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75 #define UART_LSR_THRE 0x20 /* Transmit-hold-register empty */ |
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76 #define UART_LSR_BI 0x10 /* Break interrupt indicator */ |
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77 #define UART_LSR_FE 0x08 /* Frame error indicator */ |
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78 #define UART_LSR_PE 0x04 /* Parity error indicator */ |
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79 #define UART_LSR_OE 0x02 /* Overrun error indicator */ |
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80 #define UART_LSR_DR 0x01 /* Receiver data ready */ |
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81 #define UART_LSR_INT_ANY 0x1E /* Any of the lsr-interrupt-triggering status bits */ |
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82 |
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83 /* Interrupt trigger levels. The byte-counts are for 16550A - in newer UARTs the byte-count for each ITL is higher. */ |
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84 |
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85 #define UART_FCR_ITL_1 0x00 /* 1 byte ITL */ |
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86 #define UART_FCR_ITL_2 0x40 /* 4 bytes ITL */ |
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87 #define UART_FCR_ITL_3 0x80 /* 8 bytes ITL */ |
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88 #define UART_FCR_ITL_4 0xC0 /* 14 bytes ITL */ |
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89 |
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90 #define UART_FCR_DMS 0x08 /* DMA Mode Select */ |
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91 #define UART_FCR_XFR 0x04 /* XMIT Fifo Reset */ |
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92 #define UART_FCR_RFR 0x02 /* RCVR Fifo Reset */ |
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93 #define UART_FCR_FE 0x01 /* FIFO Enable */ |
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94 |
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95 #define UART_FIFO_LENGTH 16 /* 16550A Fifo Length */ |
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96 |
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97 #define XMIT_FIFO 0 |
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98 #define RECV_FIFO 1 |
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99 #define MAX_XMIT_RETRY 4 |
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100 |
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101 struct SerialFIFO { |
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102 uint8_t data[UART_FIFO_LENGTH]; |
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103 uint8_t count; |
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104 uint8_t itl; /* Interrupt Trigger Level */ |
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105 uint8_t tail; |
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106 uint8_t head; |
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107 } typedef SerialFIFO; |
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108 |
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109 struct SerialState { |
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110 uint16_t divider; |
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111 uint8_t rbr; /* receive register */ |
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112 uint8_t thr; /* transmit holding register */ |
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113 uint8_t tsr; /* transmit shift register */ |
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114 uint8_t ier; |
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115 uint8_t iir; /* read only */ |
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116 uint8_t lcr; |
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117 uint8_t mcr; |
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118 uint8_t lsr; /* read only */ |
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119 uint8_t msr; /* read only */ |
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120 uint8_t scr; |
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121 uint8_t fcr; |
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122 /* NOTE: this hidden state is necessary for tx irq generation as |
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123 it can be reset while reading iir */ |
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124 int thr_ipending; |
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125 qemu_irq irq; |
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126 CharDriverState *chr; |
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127 int last_break_enable; |
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128 int it_shift; |
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129 int baudbase; |
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130 int tsr_retry; |
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131 |
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132 uint64_t last_xmit_ts; /* Time when the last byte was successfully sent out of the tsr */ |
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133 SerialFIFO recv_fifo; |
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134 SerialFIFO xmit_fifo; |
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135 |
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136 struct QEMUTimer *fifo_timeout_timer; |
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137 int timeout_ipending; /* timeout interrupt pending state */ |
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138 struct QEMUTimer *transmit_timer; |
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139 |
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140 |
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141 uint64_t char_transmit_time; /* time to transmit a char in ticks*/ |
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142 int poll_msl; |
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143 |
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144 struct QEMUTimer *modem_status_poll; |
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145 }; |
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146 |
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147 static void serial_receive1(void *opaque, const uint8_t *buf, int size); |
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148 |
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149 static void fifo_clear(SerialState *s, int fifo) |
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150 { |
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151 SerialFIFO *f = (fifo) ? &s->recv_fifo : &s->xmit_fifo; |
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152 memset(f->data, 0, UART_FIFO_LENGTH); |
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153 f->count = 0; |
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154 f->head = 0; |
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155 f->tail = 0; |
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156 } |
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157 |
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158 static int fifo_put(SerialState *s, int fifo, uint8_t chr) |
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159 { |
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160 SerialFIFO *f = (fifo) ? &s->recv_fifo : &s->xmit_fifo; |
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161 |
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162 f->data[f->head++] = chr; |
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163 |
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164 if (f->head == UART_FIFO_LENGTH) |
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165 f->head = 0; |
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166 f->count++; |
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167 |
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168 return 1; |
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169 } |
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170 |
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171 static uint8_t fifo_get(SerialState *s, int fifo) |
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172 { |
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173 SerialFIFO *f = (fifo) ? &s->recv_fifo : &s->xmit_fifo; |
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174 uint8_t c; |
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175 |
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176 if(f->count == 0) |
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177 return 0; |
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178 |
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179 c = f->data[f->tail++]; |
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180 if (f->tail == UART_FIFO_LENGTH) |
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181 f->tail = 0; |
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182 f->count--; |
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183 |
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184 return c; |
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185 } |
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186 |
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187 static void serial_update_irq(SerialState *s) |
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188 { |
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189 uint8_t tmp_iir = UART_IIR_NO_INT; |
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190 |
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191 if ((s->ier & UART_IER_RLSI) && (s->lsr & UART_LSR_INT_ANY)) { |
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192 tmp_iir = UART_IIR_RLSI; |
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193 } else if ((s->ier & UART_IER_RDI) && s->timeout_ipending) { |
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194 /* Note that(s->ier & UART_IER_RDI) can mask this interrupt, |
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195 * this is not in the specification but is observed on existing |
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196 * hardware. */ |
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197 tmp_iir = UART_IIR_CTI; |
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198 } else if ((s->ier & UART_IER_RDI) && (s->lsr & UART_LSR_DR)) { |
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199 if (!(s->fcr & UART_FCR_FE)) { |
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200 tmp_iir = UART_IIR_RDI; |
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201 } else if (s->recv_fifo.count >= s->recv_fifo.itl) { |
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202 tmp_iir = UART_IIR_RDI; |
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203 } |
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204 } else if ((s->ier & UART_IER_THRI) && s->thr_ipending) { |
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205 tmp_iir = UART_IIR_THRI; |
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206 } else if ((s->ier & UART_IER_MSI) && (s->msr & UART_MSR_ANY_DELTA)) { |
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207 tmp_iir = UART_IIR_MSI; |
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208 } |
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209 |
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210 s->iir = tmp_iir | (s->iir & 0xF0); |
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211 |
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212 if (tmp_iir != UART_IIR_NO_INT) { |
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213 qemu_irq_raise(s->irq); |
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214 } else { |
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215 qemu_irq_lower(s->irq); |
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216 } |
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217 } |
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218 |
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219 static void serial_update_parameters(SerialState *s) |
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220 { |
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221 int speed, parity, data_bits, stop_bits, frame_size; |
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222 QEMUSerialSetParams ssp; |
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223 |
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224 if (s->divider == 0) |
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225 return; |
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226 |
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227 frame_size = 1; |
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228 if (s->lcr & 0x08) { |
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229 if (s->lcr & 0x10) |
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230 parity = 'E'; |
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231 else |
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232 parity = 'O'; |
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233 } else { |
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234 parity = 'N'; |
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235 frame_size = 0; |
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236 } |
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237 if (s->lcr & 0x04) |
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238 stop_bits = 2; |
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239 else |
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240 stop_bits = 1; |
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241 |
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242 data_bits = (s->lcr & 0x03) + 5; |
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243 frame_size += data_bits + stop_bits; |
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244 speed = s->baudbase / s->divider; |
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245 ssp.speed = speed; |
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246 ssp.parity = parity; |
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247 ssp.data_bits = data_bits; |
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248 ssp.stop_bits = stop_bits; |
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249 s->char_transmit_time = (ticks_per_sec / speed) * frame_size; |
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250 qemu_chr_ioctl(s->chr, CHR_IOCTL_SERIAL_SET_PARAMS, &ssp); |
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251 #if 0 |
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252 printf("speed=%d parity=%c data=%d stop=%d\n", |
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253 speed, parity, data_bits, stop_bits); |
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254 #endif |
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255 } |
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256 |
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257 static void serial_update_msl(SerialState *s) |
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258 { |
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259 uint8_t omsr; |
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260 int flags; |
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261 |
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262 qemu_del_timer(s->modem_status_poll); |
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263 |
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264 if (qemu_chr_ioctl(s->chr,CHR_IOCTL_SERIAL_GET_TIOCM, &flags) == -ENOTSUP) { |
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265 s->poll_msl = -1; |
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266 return; |
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267 } |
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268 |
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269 omsr = s->msr; |
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270 |
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271 s->msr = (flags & CHR_TIOCM_CTS) ? s->msr | UART_MSR_CTS : s->msr & ~UART_MSR_CTS; |
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272 s->msr = (flags & CHR_TIOCM_DSR) ? s->msr | UART_MSR_DSR : s->msr & ~UART_MSR_DSR; |
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273 s->msr = (flags & CHR_TIOCM_CAR) ? s->msr | UART_MSR_DCD : s->msr & ~UART_MSR_DCD; |
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274 s->msr = (flags & CHR_TIOCM_RI) ? s->msr | UART_MSR_RI : s->msr & ~UART_MSR_RI; |
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275 |
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276 if (s->msr != omsr) { |
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277 /* Set delta bits */ |
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278 s->msr = s->msr | ((s->msr >> 4) ^ (omsr >> 4)); |
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279 /* UART_MSR_TERI only if change was from 1 -> 0 */ |
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280 if ((s->msr & UART_MSR_TERI) && !(omsr & UART_MSR_RI)) |
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281 s->msr &= ~UART_MSR_TERI; |
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282 serial_update_irq(s); |
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283 } |
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284 |
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285 /* The real 16550A apparently has a 250ns response latency to line status changes. |
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286 We'll be lazy and poll only every 10ms, and only poll it at all if MSI interrupts are turned on */ |
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287 |
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288 if (s->poll_msl) |
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289 qemu_mod_timer(s->modem_status_poll, qemu_get_clock(vm_clock) + ticks_per_sec / 100); |
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290 } |
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291 |
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292 static void serial_xmit(void *opaque) |
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293 { |
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294 SerialState *s = opaque; |
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295 uint64_t new_xmit_ts = qemu_get_clock(vm_clock); |
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296 |
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297 if (s->tsr_retry <= 0) { |
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298 if (s->fcr & UART_FCR_FE) { |
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299 s->tsr = fifo_get(s,XMIT_FIFO); |
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300 if (!s->xmit_fifo.count) |
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301 s->lsr |= UART_LSR_THRE; |
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302 } else { |
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303 s->tsr = s->thr; |
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304 s->lsr |= UART_LSR_THRE; |
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305 } |
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306 } |
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307 |
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308 if (s->mcr & UART_MCR_LOOP) { |
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309 /* in loopback mode, say that we just received a char */ |
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310 serial_receive1(s, &s->tsr, 1); |
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311 } else if (qemu_chr_write(s->chr, &s->tsr, 1) != 1) { |
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312 if ((s->tsr_retry > 0) && (s->tsr_retry <= MAX_XMIT_RETRY)) { |
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313 s->tsr_retry++; |
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314 qemu_mod_timer(s->transmit_timer, new_xmit_ts + s->char_transmit_time); |
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315 return; |
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316 } else if (s->poll_msl < 0) { |
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317 /* If we exceed MAX_XMIT_RETRY and the backend is not a real serial port, then |
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318 drop any further failed writes instantly, until we get one that goes through. |
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319 This is to prevent guests that log to unconnected pipes or pty's from stalling. */ |
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320 s->tsr_retry = -1; |
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321 } |
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322 } |
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323 else { |
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324 s->tsr_retry = 0; |
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325 } |
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326 |
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327 s->last_xmit_ts = qemu_get_clock(vm_clock); |
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328 if (!(s->lsr & UART_LSR_THRE)) |
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329 qemu_mod_timer(s->transmit_timer, s->last_xmit_ts + s->char_transmit_time); |
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330 |
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331 if (s->lsr & UART_LSR_THRE) { |
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332 s->lsr |= UART_LSR_TEMT; |
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333 s->thr_ipending = 1; |
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334 serial_update_irq(s); |
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335 } |
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336 } |
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337 |
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338 |
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339 static void serial_ioport_write(void *opaque, uint32_t addr, uint32_t val) |
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340 { |
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341 SerialState *s = opaque; |
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342 |
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343 addr &= 7; |
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344 #ifdef DEBUG_SERIAL |
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345 printf("serial: write addr=0x%02x val=0x%02x\n", addr, val); |
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346 #endif |
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347 switch(addr) { |
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348 default: |
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349 case 0: |
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350 if (s->lcr & UART_LCR_DLAB) { |
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351 s->divider = (s->divider & 0xff00) | val; |
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352 serial_update_parameters(s); |
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353 } else { |
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354 s->thr = (uint8_t) val; |
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355 if(s->fcr & UART_FCR_FE) { |
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356 fifo_put(s, XMIT_FIFO, s->thr); |
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357 s->thr_ipending = 0; |
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358 s->lsr &= ~UART_LSR_TEMT; |
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359 s->lsr &= ~UART_LSR_THRE; |
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360 serial_update_irq(s); |
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361 } else { |
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362 s->thr_ipending = 0; |
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363 s->lsr &= ~UART_LSR_THRE; |
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364 serial_update_irq(s); |
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365 } |
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366 serial_xmit(s); |
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367 } |
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368 break; |
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369 case 1: |
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370 if (s->lcr & UART_LCR_DLAB) { |
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371 s->divider = (s->divider & 0x00ff) | (val << 8); |
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372 serial_update_parameters(s); |
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373 } else { |
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374 s->ier = val & 0x0f; |
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375 /* If the backend device is a real serial port, turn polling of the modem |
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376 status lines on physical port on or off depending on UART_IER_MSI state */ |
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377 if (s->poll_msl >= 0) { |
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378 if (s->ier & UART_IER_MSI) { |
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379 s->poll_msl = 1; |
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380 serial_update_msl(s); |
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381 } else { |
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382 qemu_del_timer(s->modem_status_poll); |
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383 s->poll_msl = 0; |
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384 } |
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385 } |
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386 if (s->lsr & UART_LSR_THRE) { |
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387 s->thr_ipending = 1; |
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388 serial_update_irq(s); |
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389 } |
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390 } |
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391 break; |
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392 case 2: |
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393 val = val & 0xFF; |
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394 |
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395 if (s->fcr == val) |
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396 break; |
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397 |
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398 /* Did the enable/disable flag change? If so, make sure FIFOs get flushed */ |
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399 if ((val ^ s->fcr) & UART_FCR_FE) |
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400 val |= UART_FCR_XFR | UART_FCR_RFR; |
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401 |
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402 /* FIFO clear */ |
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403 |
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404 if (val & UART_FCR_RFR) { |
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405 qemu_del_timer(s->fifo_timeout_timer); |
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406 s->timeout_ipending=0; |
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407 fifo_clear(s,RECV_FIFO); |
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408 } |
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409 |
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410 if (val & UART_FCR_XFR) { |
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411 fifo_clear(s,XMIT_FIFO); |
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412 } |
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413 |
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414 if (val & UART_FCR_FE) { |
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415 s->iir |= UART_IIR_FE; |
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416 /* Set RECV_FIFO trigger Level */ |
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417 switch (val & 0xC0) { |
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418 case UART_FCR_ITL_1: |
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419 s->recv_fifo.itl = 1; |
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420 break; |
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421 case UART_FCR_ITL_2: |
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422 s->recv_fifo.itl = 4; |
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423 break; |
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424 case UART_FCR_ITL_3: |
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425 s->recv_fifo.itl = 8; |
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426 break; |
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427 case UART_FCR_ITL_4: |
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428 s->recv_fifo.itl = 14; |
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429 break; |
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430 } |
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431 } else |
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432 s->iir &= ~UART_IIR_FE; |
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433 |
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434 /* Set fcr - or at least the bits in it that are supposed to "stick" */ |
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435 s->fcr = val & 0xC9; |
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436 serial_update_irq(s); |
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437 break; |
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438 case 3: |
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439 { |
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440 int break_enable; |
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441 s->lcr = val; |
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442 serial_update_parameters(s); |
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443 break_enable = (val >> 6) & 1; |
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444 if (break_enable != s->last_break_enable) { |
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445 s->last_break_enable = break_enable; |
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446 qemu_chr_ioctl(s->chr, CHR_IOCTL_SERIAL_SET_BREAK, |
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447 &break_enable); |
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448 } |
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449 } |
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450 break; |
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451 case 4: |
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452 { |
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453 int flags; |
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454 int old_mcr = s->mcr; |
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455 s->mcr = val & 0x1f; |
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456 if (val & UART_MCR_LOOP) |
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457 break; |
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458 |
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459 if (s->poll_msl >= 0 && old_mcr != s->mcr) { |
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460 |
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461 qemu_chr_ioctl(s->chr,CHR_IOCTL_SERIAL_GET_TIOCM, &flags); |
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462 |
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463 flags &= ~(CHR_TIOCM_RTS | CHR_TIOCM_DTR); |
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464 |
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465 if (val & UART_MCR_RTS) |
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466 flags |= CHR_TIOCM_RTS; |
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467 if (val & UART_MCR_DTR) |
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468 flags |= CHR_TIOCM_DTR; |
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469 |
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470 qemu_chr_ioctl(s->chr,CHR_IOCTL_SERIAL_SET_TIOCM, &flags); |
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471 /* Update the modem status after a one-character-send wait-time, since there may be a response |
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472 from the device/computer at the other end of the serial line */ |
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473 qemu_mod_timer(s->modem_status_poll, qemu_get_clock(vm_clock) + s->char_transmit_time); |
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474 } |
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475 } |
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476 break; |
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477 case 5: |
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478 break; |
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479 case 6: |
|
480 break; |
|
481 case 7: |
|
482 s->scr = val; |
|
483 break; |
|
484 } |
|
485 } |
|
486 |
|
487 static uint32_t serial_ioport_read(void *opaque, uint32_t addr) |
|
488 { |
|
489 SerialState *s = opaque; |
|
490 uint32_t ret; |
|
491 |
|
492 addr &= 7; |
|
493 switch(addr) { |
|
494 default: |
|
495 case 0: |
|
496 if (s->lcr & UART_LCR_DLAB) { |
|
497 ret = s->divider & 0xff; |
|
498 } else { |
|
499 if(s->fcr & UART_FCR_FE) { |
|
500 ret = fifo_get(s,RECV_FIFO); |
|
501 if (s->recv_fifo.count == 0) |
|
502 s->lsr &= ~(UART_LSR_DR | UART_LSR_BI); |
|
503 else |
|
504 qemu_mod_timer(s->fifo_timeout_timer, qemu_get_clock (vm_clock) + s->char_transmit_time * 4); |
|
505 s->timeout_ipending = 0; |
|
506 } else { |
|
507 ret = s->rbr; |
|
508 s->lsr &= ~(UART_LSR_DR | UART_LSR_BI); |
|
509 } |
|
510 serial_update_irq(s); |
|
511 if (!(s->mcr & UART_MCR_LOOP)) { |
|
512 /* in loopback mode, don't receive any data */ |
|
513 qemu_chr_accept_input(s->chr); |
|
514 } |
|
515 } |
|
516 break; |
|
517 case 1: |
|
518 if (s->lcr & UART_LCR_DLAB) { |
|
519 ret = (s->divider >> 8) & 0xff; |
|
520 } else { |
|
521 ret = s->ier; |
|
522 } |
|
523 break; |
|
524 case 2: |
|
525 ret = s->iir; |
|
526 s->thr_ipending = 0; |
|
527 serial_update_irq(s); |
|
528 break; |
|
529 case 3: |
|
530 ret = s->lcr; |
|
531 break; |
|
532 case 4: |
|
533 ret = s->mcr; |
|
534 break; |
|
535 case 5: |
|
536 ret = s->lsr; |
|
537 /* Clear break interrupt */ |
|
538 if (s->lsr & UART_LSR_BI) { |
|
539 s->lsr &= ~UART_LSR_BI; |
|
540 serial_update_irq(s); |
|
541 } |
|
542 break; |
|
543 case 6: |
|
544 if (s->mcr & UART_MCR_LOOP) { |
|
545 /* in loopback, the modem output pins are connected to the |
|
546 inputs */ |
|
547 ret = (s->mcr & 0x0c) << 4; |
|
548 ret |= (s->mcr & 0x02) << 3; |
|
549 ret |= (s->mcr & 0x01) << 5; |
|
550 } else { |
|
551 if (s->poll_msl >= 0) |
|
552 serial_update_msl(s); |
|
553 ret = s->msr; |
|
554 /* Clear delta bits & msr int after read, if they were set */ |
|
555 if (s->msr & UART_MSR_ANY_DELTA) { |
|
556 s->msr &= 0xF0; |
|
557 serial_update_irq(s); |
|
558 } |
|
559 } |
|
560 break; |
|
561 case 7: |
|
562 ret = s->scr; |
|
563 break; |
|
564 } |
|
565 #ifdef DEBUG_SERIAL |
|
566 printf("serial: read addr=0x%02x val=0x%02x\n", addr, ret); |
|
567 #endif |
|
568 return ret; |
|
569 } |
|
570 |
|
571 static int serial_can_receive(SerialState *s) |
|
572 { |
|
573 if(s->fcr & UART_FCR_FE) { |
|
574 if(s->recv_fifo.count < UART_FIFO_LENGTH) |
|
575 /* Advertise (fifo.itl - fifo.count) bytes when count < ITL, and 1 if above. If UART_FIFO_LENGTH - fifo.count is |
|
576 advertised the effect will be to almost always fill the fifo completely before the guest has a chance to respond, |
|
577 effectively overriding the ITL that the guest has set. */ |
|
578 return (s->recv_fifo.count <= s->recv_fifo.itl) ? s->recv_fifo.itl - s->recv_fifo.count : 1; |
|
579 else |
|
580 return 0; |
|
581 } else { |
|
582 return !(s->lsr & UART_LSR_DR); |
|
583 } |
|
584 } |
|
585 |
|
586 static void serial_receive_break(SerialState *s) |
|
587 { |
|
588 s->rbr = 0; |
|
589 s->lsr |= UART_LSR_BI | UART_LSR_DR; |
|
590 serial_update_irq(s); |
|
591 } |
|
592 |
|
593 /* There's data in recv_fifo and s->rbr has not been read for 4 char transmit times */ |
|
594 static void fifo_timeout_int (void *opaque) { |
|
595 SerialState *s = opaque; |
|
596 if (s->recv_fifo.count) { |
|
597 s->timeout_ipending = 1; |
|
598 serial_update_irq(s); |
|
599 } |
|
600 } |
|
601 |
|
602 static int serial_can_receive1(void *opaque) |
|
603 { |
|
604 SerialState *s = opaque; |
|
605 return serial_can_receive(s); |
|
606 } |
|
607 |
|
608 static void serial_receive1(void *opaque, const uint8_t *buf, int size) |
|
609 { |
|
610 SerialState *s = opaque; |
|
611 if(s->fcr & UART_FCR_FE) { |
|
612 int i; |
|
613 for (i = 0; i < size; i++) { |
|
614 fifo_put(s, RECV_FIFO, buf[i]); |
|
615 } |
|
616 s->lsr |= UART_LSR_DR; |
|
617 /* call the timeout receive callback in 4 char transmit time */ |
|
618 qemu_mod_timer(s->fifo_timeout_timer, qemu_get_clock (vm_clock) + s->char_transmit_time * 4); |
|
619 } else { |
|
620 s->rbr = buf[0]; |
|
621 s->lsr |= UART_LSR_DR; |
|
622 } |
|
623 serial_update_irq(s); |
|
624 } |
|
625 |
|
626 static void serial_event(void *opaque, int event) |
|
627 { |
|
628 SerialState *s = opaque; |
|
629 #ifdef DEBUG_SERIAL |
|
630 printf("serial: event %x\n", event); |
|
631 #endif |
|
632 if (event == CHR_EVENT_BREAK) |
|
633 serial_receive_break(s); |
|
634 } |
|
635 |
|
636 static void serial_save(QEMUFile *f, void *opaque) |
|
637 { |
|
638 SerialState *s = opaque; |
|
639 |
|
640 qemu_put_be16s(f,&s->divider); |
|
641 qemu_put_8s(f,&s->rbr); |
|
642 qemu_put_8s(f,&s->ier); |
|
643 qemu_put_8s(f,&s->iir); |
|
644 qemu_put_8s(f,&s->lcr); |
|
645 qemu_put_8s(f,&s->mcr); |
|
646 qemu_put_8s(f,&s->lsr); |
|
647 qemu_put_8s(f,&s->msr); |
|
648 qemu_put_8s(f,&s->scr); |
|
649 qemu_put_8s(f,&s->fcr); |
|
650 } |
|
651 |
|
652 static int serial_load(QEMUFile *f, void *opaque, int version_id) |
|
653 { |
|
654 SerialState *s = opaque; |
|
655 uint8_t fcr = 0; |
|
656 |
|
657 if(version_id > 3) |
|
658 return -EINVAL; |
|
659 |
|
660 if (version_id >= 2) |
|
661 qemu_get_be16s(f, &s->divider); |
|
662 else |
|
663 s->divider = qemu_get_byte(f); |
|
664 qemu_get_8s(f,&s->rbr); |
|
665 qemu_get_8s(f,&s->ier); |
|
666 qemu_get_8s(f,&s->iir); |
|
667 qemu_get_8s(f,&s->lcr); |
|
668 qemu_get_8s(f,&s->mcr); |
|
669 qemu_get_8s(f,&s->lsr); |
|
670 qemu_get_8s(f,&s->msr); |
|
671 qemu_get_8s(f,&s->scr); |
|
672 |
|
673 if (version_id >= 3) |
|
674 qemu_get_8s(f,&fcr); |
|
675 |
|
676 /* Initialize fcr via setter to perform essential side-effects */ |
|
677 serial_ioport_write(s, 0x02, fcr); |
|
678 return 0; |
|
679 } |
|
680 |
|
681 static void serial_reset(void *opaque) |
|
682 { |
|
683 SerialState *s = opaque; |
|
684 |
|
685 s->rbr = 0; |
|
686 s->ier = 0; |
|
687 s->iir = UART_IIR_NO_INT; |
|
688 s->lcr = 0; |
|
689 s->lsr = UART_LSR_TEMT | UART_LSR_THRE; |
|
690 s->msr = UART_MSR_DCD | UART_MSR_DSR | UART_MSR_CTS; |
|
691 /* Default to 9600 baud, no parity, one stop bit */ |
|
692 s->divider = 0x0C; |
|
693 s->mcr = UART_MCR_OUT2; |
|
694 s->scr = 0; |
|
695 s->tsr_retry = 0; |
|
696 s->char_transmit_time = (ticks_per_sec / 9600) * 9; |
|
697 s->poll_msl = 0; |
|
698 |
|
699 fifo_clear(s,RECV_FIFO); |
|
700 fifo_clear(s,XMIT_FIFO); |
|
701 |
|
702 s->last_xmit_ts = qemu_get_clock(vm_clock); |
|
703 |
|
704 s->thr_ipending = 0; |
|
705 s->last_break_enable = 0; |
|
706 qemu_irq_lower(s->irq); |
|
707 } |
|
708 |
|
709 static void serial_init_core(SerialState *s, qemu_irq irq, int baudbase, |
|
710 CharDriverState *chr) |
|
711 { |
|
712 s->irq = irq; |
|
713 s->baudbase = baudbase; |
|
714 s->chr = chr; |
|
715 |
|
716 s->modem_status_poll = qemu_new_timer(vm_clock, (QEMUTimerCB *) serial_update_msl, s); |
|
717 |
|
718 s->fifo_timeout_timer = qemu_new_timer(vm_clock, (QEMUTimerCB *) fifo_timeout_int, s); |
|
719 s->transmit_timer = qemu_new_timer(vm_clock, (QEMUTimerCB *) serial_xmit, s); |
|
720 |
|
721 qemu_register_reset(serial_reset, s); |
|
722 serial_reset(s); |
|
723 |
|
724 } |
|
725 |
|
726 /* If fd is zero, it means that the serial device uses the console */ |
|
727 SerialState *serial_init(int base, qemu_irq irq, int baudbase, |
|
728 CharDriverState *chr) |
|
729 { |
|
730 SerialState *s; |
|
731 |
|
732 s = qemu_mallocz(sizeof(SerialState)); |
|
733 if (!s) |
|
734 return NULL; |
|
735 |
|
736 serial_init_core(s, irq, baudbase, chr); |
|
737 |
|
738 register_savevm("serial", base, 3, serial_save, serial_load, s); |
|
739 |
|
740 register_ioport_write(base, 8, 1, serial_ioport_write, s); |
|
741 register_ioport_read(base, 8, 1, serial_ioport_read, s); |
|
742 qemu_chr_add_handlers(chr, serial_can_receive1, serial_receive1, |
|
743 serial_event, s); |
|
744 return s; |
|
745 } |
|
746 |
|
747 /* Memory mapped interface */ |
|
748 uint32_t serial_mm_readb (void *opaque, target_phys_addr_t addr) |
|
749 { |
|
750 SerialState *s = opaque; |
|
751 |
|
752 return serial_ioport_read(s, addr >> s->it_shift) & 0xFF; |
|
753 } |
|
754 |
|
755 void serial_mm_writeb (void *opaque, |
|
756 target_phys_addr_t addr, uint32_t value) |
|
757 { |
|
758 SerialState *s = opaque; |
|
759 |
|
760 serial_ioport_write(s, addr >> s->it_shift, value & 0xFF); |
|
761 } |
|
762 |
|
763 uint32_t serial_mm_readw (void *opaque, target_phys_addr_t addr) |
|
764 { |
|
765 SerialState *s = opaque; |
|
766 uint32_t val; |
|
767 |
|
768 val = serial_ioport_read(s, addr >> s->it_shift) & 0xFFFF; |
|
769 #ifdef TARGET_WORDS_BIGENDIAN |
|
770 val = bswap16(val); |
|
771 #endif |
|
772 return val; |
|
773 } |
|
774 |
|
775 void serial_mm_writew (void *opaque, |
|
776 target_phys_addr_t addr, uint32_t value) |
|
777 { |
|
778 SerialState *s = opaque; |
|
779 #ifdef TARGET_WORDS_BIGENDIAN |
|
780 value = bswap16(value); |
|
781 #endif |
|
782 serial_ioport_write(s, addr >> s->it_shift, value & 0xFFFF); |
|
783 } |
|
784 |
|
785 uint32_t serial_mm_readl (void *opaque, target_phys_addr_t addr) |
|
786 { |
|
787 SerialState *s = opaque; |
|
788 uint32_t val; |
|
789 |
|
790 val = serial_ioport_read(s, addr >> s->it_shift); |
|
791 #ifdef TARGET_WORDS_BIGENDIAN |
|
792 val = bswap32(val); |
|
793 #endif |
|
794 return val; |
|
795 } |
|
796 |
|
797 void serial_mm_writel (void *opaque, |
|
798 target_phys_addr_t addr, uint32_t value) |
|
799 { |
|
800 SerialState *s = opaque; |
|
801 #ifdef TARGET_WORDS_BIGENDIAN |
|
802 value = bswap32(value); |
|
803 #endif |
|
804 serial_ioport_write(s, addr >> s->it_shift, value); |
|
805 } |
|
806 |
|
807 static CPUReadMemoryFunc *serial_mm_read[] = { |
|
808 &serial_mm_readb, |
|
809 &serial_mm_readw, |
|
810 &serial_mm_readl, |
|
811 }; |
|
812 |
|
813 static CPUWriteMemoryFunc *serial_mm_write[] = { |
|
814 &serial_mm_writeb, |
|
815 &serial_mm_writew, |
|
816 &serial_mm_writel, |
|
817 }; |
|
818 |
|
819 SerialState *serial_mm_init (target_phys_addr_t base, int it_shift, |
|
820 qemu_irq irq, int baudbase, |
|
821 CharDriverState *chr, int ioregister) |
|
822 { |
|
823 SerialState *s; |
|
824 int s_io_memory; |
|
825 |
|
826 s = qemu_mallocz(sizeof(SerialState)); |
|
827 if (!s) |
|
828 return NULL; |
|
829 |
|
830 s->it_shift = it_shift; |
|
831 |
|
832 serial_init_core(s, irq, baudbase, chr); |
|
833 register_savevm("serial", base, 3, serial_save, serial_load, s); |
|
834 |
|
835 if (ioregister) { |
|
836 s_io_memory = cpu_register_io_memory(0, serial_mm_read, |
|
837 serial_mm_write, s); |
|
838 cpu_register_physical_memory(base, 8 << it_shift, s_io_memory); |
|
839 } |
|
840 qemu_chr_add_handlers(chr, serial_can_receive1, serial_receive1, |
|
841 serial_event, s); |
|
842 serial_update_msl(s); |
|
843 return s; |
|
844 } |