1 | /** |
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2 | * @file |
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3 | * |
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4 | * This file contains the TTY driver for the National Semiconductor NS16550. |
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5 | * |
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6 | * This part is widely cloned and second sourced. It is found in a number |
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7 | * of "Super IO" controllers. |
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8 | * |
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9 | * This driver uses the termios pseudo driver. |
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10 | */ |
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11 | |
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12 | /* |
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13 | * COPYRIGHT (c) 1998 by Radstone Technology |
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14 | * |
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15 | * THIS FILE IS PROVIDED TO YOU, THE USER, "AS IS", WITHOUT WARRANTY OF ANY |
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16 | * KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE |
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17 | * IMPLIED WARRANTY OF FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK |
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18 | * AS TO THE QUALITY AND PERFORMANCE OF ALL CODE IN THIS FILE IS WITH YOU. |
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19 | * |
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20 | * You are hereby granted permission to use, copy, modify, and distribute |
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21 | * this file, provided that this notice, plus the above copyright notice |
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22 | * and disclaimer, appears in all copies. Radstone Technology will provide |
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23 | * no support for this code. |
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24 | * |
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25 | * COPYRIGHT (c) 1989-2012. |
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26 | * On-Line Applications Research Corporation (OAR). |
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27 | * |
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28 | * The license and distribution terms for this file may be |
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29 | * found in the file LICENSE in this distribution or at |
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30 | * http://www.rtems.org/license/LICENSE. |
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31 | */ |
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32 | |
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33 | #include <stdlib.h> |
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34 | |
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35 | #include <rtems/bspIo.h> |
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36 | |
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37 | #include <bsp.h> |
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38 | |
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39 | #include "ns16550.h" |
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40 | #include "ns16550_p.h" |
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41 | |
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42 | #if defined(BSP_FEATURE_IRQ_EXTENSION) |
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43 | #include <bsp/irq.h> |
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44 | #elif defined(BSP_FEATURE_IRQ_LEGACY) |
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45 | #include <bsp/irq.h> |
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46 | #elif defined(__PPC__) || defined(__i386__) |
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47 | #include <bsp/irq.h> |
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48 | #define BSP_FEATURE_IRQ_LEGACY |
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49 | #ifdef BSP_SHARED_HANDLER_SUPPORT |
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50 | #define BSP_FEATURE_IRQ_LEGACY_SHARED_HANDLER_SUPPORT |
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51 | #endif |
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52 | #endif |
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53 | |
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54 | static uint32_t NS16550_GetBaudDivisor(ns16550_context *ctx, uint32_t baud) |
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55 | { |
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56 | uint32_t clock = ctx->clock; |
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57 | uint32_t baudDivisor = (clock != 0 ? clock : 115200) / (baud * 16); |
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58 | |
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59 | if (ctx->has_fractional_divider_register) { |
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60 | uint32_t fractionalDivider = 0x10; |
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61 | uint32_t err = baud; |
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62 | uint32_t mulVal; |
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63 | uint32_t divAddVal; |
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64 | |
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65 | clock /= 16 * baudDivisor; |
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66 | for (mulVal = 1; mulVal < 16; ++mulVal) { |
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67 | for (divAddVal = 0; divAddVal < mulVal; ++divAddVal) { |
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68 | uint32_t actual = (mulVal * clock) / (mulVal + divAddVal); |
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69 | uint32_t newErr = actual > baud ? actual - baud : baud - actual; |
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70 | |
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71 | if (newErr < err) { |
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72 | err = newErr; |
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73 | fractionalDivider = (mulVal << 4) | divAddVal; |
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74 | } |
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75 | } |
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76 | } |
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77 | |
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78 | (*ctx->set_reg)( |
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79 | ctx->port, |
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80 | NS16550_FRACTIONAL_DIVIDER, |
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81 | fractionalDivider |
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82 | ); |
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83 | } |
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84 | |
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85 | return baudDivisor; |
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86 | } |
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87 | |
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88 | /* |
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89 | * ns16550_enable_interrupts |
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90 | * |
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91 | * This routine initializes the port to have the specified interrupts masked. |
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92 | */ |
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93 | static void ns16550_enable_interrupts( |
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94 | ns16550_context *ctx, |
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95 | int mask |
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96 | ) |
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97 | { |
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98 | (*ctx->set_reg)(ctx->port, NS16550_INTERRUPT_ENABLE, mask); |
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99 | } |
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100 | |
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101 | static void ns16550_clear_and_set_interrupts( |
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102 | ns16550_context *ctx, |
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103 | uint8_t clear, |
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104 | uint8_t set |
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105 | ) |
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106 | { |
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107 | rtems_interrupt_lock_context lock_context; |
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108 | ns16550_get_reg get_reg = ctx->get_reg; |
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109 | ns16550_set_reg set_reg = ctx->set_reg; |
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110 | uintptr_t port = ctx->port; |
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111 | uint8_t val; |
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112 | |
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113 | rtems_termios_device_lock_acquire(&ctx->base, &lock_context); |
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114 | val = (*get_reg)(port, NS16550_INTERRUPT_ENABLE); |
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115 | val &= ~clear; |
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116 | val |= set; |
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117 | (*set_reg)(port, NS16550_INTERRUPT_ENABLE, val); |
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118 | rtems_termios_device_lock_release(&ctx->base, &lock_context); |
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119 | } |
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120 | |
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121 | /* |
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122 | * ns16550_probe |
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123 | */ |
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124 | |
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125 | bool ns16550_probe(rtems_termios_device_context *base) |
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126 | { |
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127 | ns16550_context *ctx = (ns16550_context *) base; |
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128 | uintptr_t pNS16550; |
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129 | uint8_t ucDataByte; |
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130 | uint32_t ulBaudDivisor; |
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131 | ns16550_set_reg setReg; |
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132 | ns16550_get_reg getReg; |
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133 | |
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134 | ctx->modem_control = SP_MODEM_IRQ; |
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135 | |
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136 | pNS16550 = ctx->port; |
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137 | setReg = ctx->set_reg; |
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138 | getReg = ctx->get_reg; |
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139 | |
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140 | /* Clear the divisor latch, clear all interrupt enables, |
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141 | * and reset and |
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142 | * disable the FIFO's. |
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143 | */ |
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144 | |
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145 | (*setReg)(pNS16550, NS16550_LINE_CONTROL, 0x0); |
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146 | ns16550_enable_interrupts(ctx, NS16550_DISABLE_ALL_INTR ); |
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147 | |
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148 | /* Set the divisor latch and set the baud rate. */ |
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149 | |
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150 | ulBaudDivisor = NS16550_GetBaudDivisor(ctx, ctx->initial_baud); |
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151 | ucDataByte = SP_LINE_DLAB; |
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152 | (*setReg)(pNS16550, NS16550_LINE_CONTROL, ucDataByte); |
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153 | |
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154 | /* XXX */ |
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155 | (*setReg)(pNS16550,NS16550_TRANSMIT_BUFFER,(uint8_t)(ulBaudDivisor & 0xffU)); |
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156 | (*setReg)( |
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157 | pNS16550,NS16550_INTERRUPT_ENABLE, |
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158 | (uint8_t)(( ulBaudDivisor >> 8 ) & 0xffU ) |
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159 | ); |
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160 | |
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161 | /* Clear the divisor latch and set the character size to eight bits */ |
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162 | /* with one stop bit and no parity checking. */ |
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163 | ucDataByte = EIGHT_BITS; |
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164 | (*setReg)(pNS16550, NS16550_LINE_CONTROL, ucDataByte); |
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165 | |
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166 | /* Enable and reset transmit and receive FIFOs. TJA */ |
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167 | ucDataByte = SP_FIFO_ENABLE; |
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168 | (*setReg)(pNS16550, NS16550_FIFO_CONTROL, ucDataByte); |
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169 | |
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170 | ucDataByte = SP_FIFO_ENABLE | SP_FIFO_RXRST | SP_FIFO_TXRST; |
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171 | (*setReg)(pNS16550, NS16550_FIFO_CONTROL, ucDataByte); |
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172 | |
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173 | ns16550_enable_interrupts(ctx, NS16550_DISABLE_ALL_INTR); |
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174 | |
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175 | /* Set data terminal ready. */ |
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176 | /* And open interrupt tristate line */ |
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177 | (*setReg)(pNS16550, NS16550_MODEM_CONTROL,ctx->modem_control); |
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178 | |
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179 | (*getReg)(pNS16550, NS16550_LINE_STATUS ); |
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180 | (*getReg)(pNS16550, NS16550_RECEIVE_BUFFER ); |
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181 | |
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182 | return true; |
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183 | } |
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184 | |
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185 | static size_t ns16550_write_to_fifo( |
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186 | const ns16550_context *ctx, |
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187 | const char *buf, |
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188 | size_t len |
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189 | ) |
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190 | { |
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191 | uint32_t port = ctx->port; |
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192 | ns16550_set_reg set = ctx->set_reg; |
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193 | size_t out = len > SP_FIFO_SIZE ? SP_FIFO_SIZE : len; |
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194 | size_t i; |
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195 | |
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196 | for (i = 0; i < out; ++i) { |
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197 | (*set)(port, NS16550_TRANSMIT_BUFFER, buf[i]); |
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198 | } |
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199 | |
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200 | return out; |
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201 | } |
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202 | |
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203 | /** |
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204 | * @brief Process interrupt. |
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205 | */ |
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206 | static void ns16550_isr(void *arg) |
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207 | { |
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208 | rtems_termios_tty *tty = arg; |
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209 | ns16550_context *ctx = rtems_termios_get_device_context(tty); |
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210 | uint32_t port = ctx->port; |
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211 | ns16550_get_reg get = ctx->get_reg; |
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212 | int i = 0; |
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213 | char buf [SP_FIFO_SIZE]; |
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214 | |
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215 | /* Iterate until no more interrupts are pending */ |
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216 | do { |
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217 | /* Fetch received characters */ |
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218 | for (i = 0; i < SP_FIFO_SIZE; ++i) { |
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219 | if ((get( port, NS16550_LINE_STATUS) & SP_LSR_RDY) != 0) { |
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220 | buf [i] = (char) get(port, NS16550_RECEIVE_BUFFER); |
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221 | } else { |
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222 | break; |
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223 | } |
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224 | } |
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225 | |
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226 | /* Enqueue fetched characters */ |
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227 | rtems_termios_enqueue_raw_characters(tty, buf, i); |
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228 | |
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229 | /* Do transmit */ |
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230 | if (ctx->out_total > 0 |
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231 | && (get(port, NS16550_LINE_STATUS) & SP_LSR_THOLD) != 0) { |
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232 | size_t current = ctx->out_current; |
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233 | |
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234 | ctx->out_buf += current; |
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235 | ctx->out_remaining -= current; |
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236 | |
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237 | if (ctx->out_remaining > 0) { |
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238 | ctx->out_current = |
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239 | ns16550_write_to_fifo(ctx, ctx->out_buf, ctx->out_remaining); |
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240 | } else { |
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241 | rtems_termios_dequeue_characters(tty, ctx->out_total); |
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242 | } |
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243 | } |
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244 | } while ((get( port, NS16550_INTERRUPT_ID) & SP_IID_0) == 0); |
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245 | } |
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246 | |
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247 | static void ns16550_isr_task(void *arg) |
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248 | { |
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249 | rtems_termios_tty *tty = arg; |
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250 | ns16550_context *ctx = rtems_termios_get_device_context(tty); |
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251 | uint8_t status = (*ctx->get_reg)(ctx->port, NS16550_LINE_STATUS); |
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252 | |
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253 | if ((status & SP_LSR_RDY) != 0) { |
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254 | ns16550_clear_and_set_interrupts(ctx, SP_INT_RX_ENABLE, 0); |
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255 | rtems_termios_rxirq_occured(tty); |
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256 | } |
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257 | |
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258 | if (ctx->out_total > 0 && (status & SP_LSR_THOLD) != 0) { |
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259 | size_t current = ctx->out_current; |
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260 | |
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261 | ctx->out_buf += current; |
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262 | ctx->out_remaining -= current; |
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263 | |
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264 | if (ctx->out_remaining > 0) { |
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265 | ctx->out_current = |
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266 | ns16550_write_to_fifo(ctx, ctx->out_buf, ctx->out_remaining); |
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267 | } else { |
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268 | size_t done = ctx->out_total; |
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269 | |
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270 | ctx->out_total = 0; |
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271 | ns16550_clear_and_set_interrupts(ctx, SP_INT_TX_ENABLE, 0); |
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272 | rtems_termios_dequeue_characters(tty, done); |
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273 | } |
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274 | } |
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275 | } |
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276 | |
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277 | static int ns16550_read_task(rtems_termios_device_context *base) |
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278 | { |
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279 | ns16550_context *ctx = (ns16550_context *) base; |
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280 | uint32_t port = ctx->port; |
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281 | ns16550_get_reg get = ctx->get_reg; |
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282 | char buf[SP_FIFO_SIZE]; |
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283 | int i; |
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284 | |
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285 | for (i = 0; i < SP_FIFO_SIZE; ++i) { |
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286 | if ((get(port, NS16550_LINE_STATUS) & SP_LSR_RDY) != 0) { |
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287 | buf[i] = (char) get(port, NS16550_RECEIVE_BUFFER); |
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288 | } else { |
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289 | break; |
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290 | } |
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291 | } |
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292 | |
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293 | rtems_termios_enqueue_raw_characters(ctx->tty, buf, i); |
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294 | ns16550_clear_and_set_interrupts(ctx, 0, SP_INT_RX_ENABLE); |
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295 | |
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296 | return -1; |
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297 | } |
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298 | |
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299 | /* |
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300 | * ns16550_initialize_interrupts |
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301 | * |
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302 | * This routine initializes the port to operate in interrupt driver mode. |
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303 | */ |
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304 | static void ns16550_initialize_interrupts( |
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305 | struct rtems_termios_tty *tty, |
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306 | ns16550_context *ctx, |
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307 | void (*isr)(void *) |
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308 | ) |
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309 | { |
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310 | #ifdef BSP_FEATURE_IRQ_EXTENSION |
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311 | { |
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312 | rtems_status_code sc = RTEMS_SUCCESSFUL; |
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313 | sc = rtems_interrupt_handler_install( |
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314 | ctx->irq, |
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315 | "NS16550", |
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316 | RTEMS_INTERRUPT_SHARED, |
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317 | isr, |
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318 | tty |
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319 | ); |
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320 | if (sc != RTEMS_SUCCESSFUL) { |
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321 | /* FIXME */ |
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322 | printk( "%s: Error: Install interrupt handler\n", __func__); |
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323 | rtems_fatal_error_occurred( 0xdeadbeef); |
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324 | } |
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325 | } |
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326 | #elif defined(BSP_FEATURE_IRQ_LEGACY) |
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327 | { |
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328 | int rv = 0; |
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329 | #ifdef BSP_FEATURE_IRQ_LEGACY_SHARED_HANDLER_SUPPORT |
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330 | rtems_irq_connect_data cd = { |
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331 | ctx->irq, |
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332 | isr, |
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333 | tty, |
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334 | NULL, |
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335 | NULL, |
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336 | NULL, |
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337 | NULL |
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338 | }; |
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339 | rv = BSP_install_rtems_shared_irq_handler( &cd); |
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340 | #else |
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341 | rtems_irq_connect_data cd = { |
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342 | ctx->irq, |
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343 | isr, |
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344 | tty, |
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345 | NULL, |
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346 | NULL, |
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347 | NULL |
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348 | }; |
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349 | rv = BSP_install_rtems_irq_handler( &cd); |
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350 | #endif |
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351 | if (rv == 0) { |
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352 | /* FIXME */ |
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353 | printk( "%s: Error: Install interrupt handler\n", __func__); |
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354 | rtems_fatal_error_occurred( 0xdeadbeef); |
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355 | } |
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356 | } |
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357 | #endif |
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358 | } |
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359 | |
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360 | /* |
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361 | * ns16550_open |
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362 | */ |
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363 | |
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364 | static bool ns16550_open( |
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365 | struct rtems_termios_tty *tty, |
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366 | rtems_termios_device_context *base, |
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367 | struct termios *term, |
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368 | rtems_libio_open_close_args_t *args |
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369 | ) |
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370 | { |
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371 | ns16550_context *ctx = (ns16550_context *) base; |
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372 | |
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373 | ctx->tty = tty; |
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374 | |
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375 | /* Set initial baud */ |
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376 | rtems_termios_set_initial_baud(tty, ctx->initial_baud); |
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377 | |
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378 | if (tty->handler.mode == TERMIOS_IRQ_DRIVEN) { |
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379 | ns16550_initialize_interrupts(tty, ctx, ns16550_isr); |
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380 | ns16550_enable_interrupts(ctx, NS16550_ENABLE_ALL_INTR_EXCEPT_TX); |
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381 | } else if (tty->handler.mode == TERMIOS_TASK_DRIVEN) { |
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382 | ns16550_initialize_interrupts(tty, ctx, ns16550_isr_task); |
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383 | ns16550_enable_interrupts(ctx, NS16550_ENABLE_ALL_INTR_EXCEPT_TX); |
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384 | } |
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385 | |
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386 | return true; |
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387 | } |
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388 | |
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389 | static void ns16550_cleanup_interrupts( |
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390 | struct rtems_termios_tty *tty, |
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391 | ns16550_context *ctx, |
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392 | void (*isr)(void *) |
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393 | ) |
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394 | { |
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395 | #if defined(BSP_FEATURE_IRQ_EXTENSION) |
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396 | rtems_status_code sc = RTEMS_SUCCESSFUL; |
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397 | sc = rtems_interrupt_handler_remove( |
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398 | ctx->irq, |
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399 | isr, |
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400 | tty |
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401 | ); |
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402 | if (sc != RTEMS_SUCCESSFUL) { |
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403 | /* FIXME */ |
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404 | printk("%s: Error: Remove interrupt handler\n", __func__); |
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405 | rtems_fatal_error_occurred(0xdeadbeef); |
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406 | } |
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407 | #elif defined(BSP_FEATURE_IRQ_LEGACY) |
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408 | int rv = 0; |
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409 | rtems_irq_connect_data cd = { |
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410 | .name = ctx->irq, |
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411 | .hdl = isr, |
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412 | .handle = tty |
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413 | }; |
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414 | rv = BSP_remove_rtems_irq_handler(&cd); |
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415 | if (rv == 0) { |
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416 | /* FIXME */ |
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417 | printk("%s: Error: Remove interrupt handler\n", __func__); |
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418 | rtems_fatal_error_occurred(0xdeadbeef); |
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419 | } |
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420 | #endif |
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421 | } |
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422 | |
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423 | /* |
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424 | * ns16550_close |
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425 | */ |
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426 | |
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427 | static void ns16550_close( |
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428 | struct rtems_termios_tty *tty, |
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429 | rtems_termios_device_context *base, |
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430 | rtems_libio_open_close_args_t *args |
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431 | ) |
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432 | { |
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433 | ns16550_context *ctx = (ns16550_context *) base; |
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434 | |
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435 | ns16550_enable_interrupts(ctx, NS16550_DISABLE_ALL_INTR); |
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436 | |
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437 | if (tty->handler.mode == TERMIOS_IRQ_DRIVEN) { |
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438 | ns16550_cleanup_interrupts(tty, ctx, ns16550_isr); |
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439 | } else if (tty->handler.mode == TERMIOS_TASK_DRIVEN) { |
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440 | ns16550_cleanup_interrupts(tty, ctx, ns16550_isr_task); |
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441 | } |
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442 | } |
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443 | |
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444 | /** |
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445 | * @brief Polled write for NS16550. |
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446 | */ |
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447 | void ns16550_polled_putchar(rtems_termios_device_context *base, char out) |
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448 | { |
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449 | ns16550_context *ctx = (ns16550_context *) base; |
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450 | uintptr_t port = ctx->port; |
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451 | ns16550_get_reg get = ctx->get_reg; |
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452 | ns16550_set_reg set = ctx->set_reg; |
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453 | uint32_t status = 0; |
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454 | rtems_interrupt_lock_context lock_context; |
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455 | |
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456 | /* Save port interrupt mask */ |
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457 | uint32_t interrupt_mask = get( port, NS16550_INTERRUPT_ENABLE); |
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458 | |
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459 | /* Disable port interrupts */ |
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460 | ns16550_enable_interrupts(ctx, NS16550_DISABLE_ALL_INTR); |
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461 | |
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462 | while (true) { |
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463 | /* Try to transmit the character in a critical section */ |
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464 | rtems_termios_device_lock_acquire(&ctx->base, &lock_context); |
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465 | |
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466 | /* Read the transmitter holding register and check it */ |
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467 | status = get( port, NS16550_LINE_STATUS); |
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468 | if ((status & SP_LSR_THOLD) != 0) { |
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469 | /* Transmit character */ |
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470 | set( port, NS16550_TRANSMIT_BUFFER, out); |
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471 | |
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472 | /* Finished */ |
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473 | rtems_termios_device_lock_release(&ctx->base, &lock_context); |
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474 | break; |
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475 | } else { |
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476 | rtems_termios_device_lock_release(&ctx->base, &lock_context); |
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477 | } |
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478 | |
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479 | /* Wait for transmitter holding register to be empty */ |
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480 | do { |
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481 | status = get( port, NS16550_LINE_STATUS); |
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482 | } while ((status & SP_LSR_THOLD) == 0); |
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483 | } |
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484 | |
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485 | /* Restore port interrupt mask */ |
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486 | set( port, NS16550_INTERRUPT_ENABLE, interrupt_mask); |
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487 | } |
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488 | |
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489 | /* |
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490 | * These routines provide control of the RTS and DTR lines |
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491 | */ |
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492 | |
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493 | /* |
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494 | * ns16550_assert_RTS |
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495 | */ |
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496 | |
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497 | static void ns16550_assert_RTS(rtems_termios_device_context *base) |
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498 | { |
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499 | ns16550_context *ctx = (ns16550_context *) base; |
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500 | rtems_interrupt_lock_context lock_context; |
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501 | |
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502 | /* |
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503 | * Assert RTS |
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504 | */ |
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505 | rtems_termios_device_lock_acquire(base, &lock_context); |
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506 | ctx->modem_control |= SP_MODEM_RTS; |
---|
507 | (*ctx->set_reg)(ctx->port, NS16550_MODEM_CONTROL, ctx->modem_control); |
---|
508 | rtems_termios_device_lock_release(base, &lock_context); |
---|
509 | } |
---|
510 | |
---|
511 | /* |
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512 | * ns16550_negate_RTS |
---|
513 | */ |
---|
514 | |
---|
515 | static void ns16550_negate_RTS(rtems_termios_device_context *base) |
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516 | { |
---|
517 | ns16550_context *ctx = (ns16550_context *) base; |
---|
518 | rtems_interrupt_lock_context lock_context; |
---|
519 | |
---|
520 | /* |
---|
521 | * Negate RTS |
---|
522 | */ |
---|
523 | rtems_termios_device_lock_acquire(base, &lock_context); |
---|
524 | ctx->modem_control &= ~SP_MODEM_RTS; |
---|
525 | (*ctx->set_reg)(ctx->port, NS16550_MODEM_CONTROL, ctx->modem_control); |
---|
526 | rtems_termios_device_lock_release(base, &lock_context); |
---|
527 | } |
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528 | |
---|
529 | /* |
---|
530 | * These flow control routines utilise a connection from the local DTR |
---|
531 | * line to the remote CTS line |
---|
532 | */ |
---|
533 | |
---|
534 | /* |
---|
535 | * ns16550_assert_DTR |
---|
536 | */ |
---|
537 | |
---|
538 | static void ns16550_assert_DTR(rtems_termios_device_context *base) |
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539 | { |
---|
540 | ns16550_context *ctx = (ns16550_context *) base; |
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541 | rtems_interrupt_lock_context lock_context; |
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542 | |
---|
543 | /* |
---|
544 | * Assert DTR |
---|
545 | */ |
---|
546 | rtems_termios_device_lock_acquire(base, &lock_context); |
---|
547 | ctx->modem_control |= SP_MODEM_DTR; |
---|
548 | (*ctx->set_reg)(ctx->port, NS16550_MODEM_CONTROL, ctx->modem_control); |
---|
549 | rtems_termios_device_lock_release(base, &lock_context); |
---|
550 | } |
---|
551 | |
---|
552 | /* |
---|
553 | * ns16550_negate_DTR |
---|
554 | */ |
---|
555 | |
---|
556 | static void ns16550_negate_DTR(rtems_termios_device_context *base) |
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557 | { |
---|
558 | ns16550_context *ctx = (ns16550_context *) base; |
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559 | rtems_interrupt_lock_context lock_context; |
---|
560 | |
---|
561 | /* |
---|
562 | * Negate DTR |
---|
563 | */ |
---|
564 | rtems_termios_device_lock_acquire(base, &lock_context); |
---|
565 | ctx->modem_control &=~SP_MODEM_DTR; |
---|
566 | (*ctx->set_reg)(ctx->port, NS16550_MODEM_CONTROL,ctx->modem_control); |
---|
567 | rtems_termios_device_lock_release(base, &lock_context); |
---|
568 | } |
---|
569 | |
---|
570 | /* |
---|
571 | * ns16550_set_attributes |
---|
572 | * |
---|
573 | * This function sets the channel to reflect the requested termios |
---|
574 | * port settings. |
---|
575 | */ |
---|
576 | |
---|
577 | static bool ns16550_set_attributes( |
---|
578 | rtems_termios_device_context *base, |
---|
579 | const struct termios *t |
---|
580 | ) |
---|
581 | { |
---|
582 | ns16550_context *ctx = (ns16550_context *) base; |
---|
583 | uint32_t pNS16550; |
---|
584 | uint32_t ulBaudDivisor; |
---|
585 | uint8_t ucLineControl; |
---|
586 | uint32_t baud_requested; |
---|
587 | ns16550_set_reg setReg; |
---|
588 | rtems_interrupt_lock_context lock_context; |
---|
589 | |
---|
590 | pNS16550 = ctx->port; |
---|
591 | setReg = ctx->set_reg; |
---|
592 | |
---|
593 | /* |
---|
594 | * Calculate the baud rate divisor |
---|
595 | * |
---|
596 | * Assert ensures there is no division by 0. |
---|
597 | */ |
---|
598 | |
---|
599 | baud_requested = rtems_termios_baud_to_number(t->c_cflag); |
---|
600 | _Assert( baud_requested != 0 ); |
---|
601 | |
---|
602 | ulBaudDivisor = NS16550_GetBaudDivisor(ctx, baud_requested); |
---|
603 | |
---|
604 | ucLineControl = 0; |
---|
605 | |
---|
606 | /* |
---|
607 | * Parity |
---|
608 | */ |
---|
609 | |
---|
610 | if (t->c_cflag & PARENB) { |
---|
611 | ucLineControl |= SP_LINE_PAR; |
---|
612 | if (!(t->c_cflag & PARODD)) |
---|
613 | ucLineControl |= SP_LINE_ODD; |
---|
614 | } |
---|
615 | |
---|
616 | /* |
---|
617 | * Character Size |
---|
618 | */ |
---|
619 | |
---|
620 | if (t->c_cflag & CSIZE) { |
---|
621 | switch (t->c_cflag & CSIZE) { |
---|
622 | case CS5: ucLineControl |= FIVE_BITS; break; |
---|
623 | case CS6: ucLineControl |= SIX_BITS; break; |
---|
624 | case CS7: ucLineControl |= SEVEN_BITS; break; |
---|
625 | case CS8: ucLineControl |= EIGHT_BITS; break; |
---|
626 | } |
---|
627 | } else { |
---|
628 | ucLineControl |= EIGHT_BITS; /* default to 9600,8,N,1 */ |
---|
629 | } |
---|
630 | |
---|
631 | /* |
---|
632 | * Stop Bits |
---|
633 | */ |
---|
634 | |
---|
635 | if (t->c_cflag & CSTOPB) { |
---|
636 | ucLineControl |= SP_LINE_STOP; /* 2 stop bits */ |
---|
637 | } else { |
---|
638 | ; /* 1 stop bit */ |
---|
639 | } |
---|
640 | |
---|
641 | /* |
---|
642 | * Now actually set the chip |
---|
643 | */ |
---|
644 | |
---|
645 | rtems_termios_device_lock_acquire(base, &lock_context); |
---|
646 | |
---|
647 | /* |
---|
648 | * Set the baud rate |
---|
649 | * |
---|
650 | * NOTE: When the Divisor Latch Access Bit (DLAB) is set to 1, |
---|
651 | * the transmit buffer and interrupt enable registers |
---|
652 | * turn into the LSB and MSB divisor latch registers. |
---|
653 | */ |
---|
654 | |
---|
655 | (*setReg)(pNS16550, NS16550_LINE_CONTROL, SP_LINE_DLAB); |
---|
656 | (*setReg)(pNS16550, NS16550_TRANSMIT_BUFFER, ulBaudDivisor&0xff); |
---|
657 | (*setReg)(pNS16550, NS16550_INTERRUPT_ENABLE, (ulBaudDivisor>>8)&0xff); |
---|
658 | |
---|
659 | /* |
---|
660 | * Now write the line control |
---|
661 | */ |
---|
662 | (*setReg)(pNS16550, NS16550_LINE_CONTROL, ucLineControl ); |
---|
663 | |
---|
664 | rtems_termios_device_lock_release(base, &lock_context); |
---|
665 | |
---|
666 | return true; |
---|
667 | } |
---|
668 | |
---|
669 | /** |
---|
670 | * @brief Transmits up to @a len characters from @a buf. |
---|
671 | * |
---|
672 | * This routine is invoked either from task context with disabled interrupts to |
---|
673 | * start a new transmission process with exactly one character in case of an |
---|
674 | * idle output state or from the interrupt handler to refill the transmitter. |
---|
675 | * |
---|
676 | * Returns always zero. |
---|
677 | */ |
---|
678 | static void ns16550_write_support_int( |
---|
679 | rtems_termios_device_context *base, |
---|
680 | const char *buf, |
---|
681 | size_t len |
---|
682 | ) |
---|
683 | { |
---|
684 | ns16550_context *ctx = (ns16550_context *) base; |
---|
685 | |
---|
686 | ctx->out_total = len; |
---|
687 | |
---|
688 | if (len > 0) { |
---|
689 | ctx->out_remaining = len; |
---|
690 | ctx->out_buf = buf; |
---|
691 | ctx->out_current = ns16550_write_to_fifo(ctx, buf, len); |
---|
692 | |
---|
693 | ns16550_enable_interrupts(ctx, NS16550_ENABLE_ALL_INTR); |
---|
694 | } else { |
---|
695 | ns16550_enable_interrupts(ctx, NS16550_ENABLE_ALL_INTR_EXCEPT_TX); |
---|
696 | } |
---|
697 | } |
---|
698 | |
---|
699 | static void ns16550_write_support_task( |
---|
700 | rtems_termios_device_context *base, |
---|
701 | const char *buf, |
---|
702 | size_t len |
---|
703 | ) |
---|
704 | { |
---|
705 | ns16550_context *ctx = (ns16550_context *) base; |
---|
706 | |
---|
707 | ctx->out_total = len; |
---|
708 | |
---|
709 | if (len > 0) { |
---|
710 | ctx->out_remaining = len; |
---|
711 | ctx->out_buf = buf; |
---|
712 | ctx->out_current = ns16550_write_to_fifo(ctx, buf, len); |
---|
713 | |
---|
714 | ns16550_clear_and_set_interrupts(ctx, 0, SP_INT_TX_ENABLE); |
---|
715 | } |
---|
716 | } |
---|
717 | |
---|
718 | /* |
---|
719 | * ns16550_write_support_polled |
---|
720 | * |
---|
721 | * Console Termios output entry point. |
---|
722 | * |
---|
723 | */ |
---|
724 | |
---|
725 | static void ns16550_write_support_polled( |
---|
726 | rtems_termios_device_context *base, |
---|
727 | const char *buf, |
---|
728 | size_t len |
---|
729 | ) |
---|
730 | { |
---|
731 | size_t nwrite = 0; |
---|
732 | |
---|
733 | /* |
---|
734 | * poll each byte in the string out of the port. |
---|
735 | */ |
---|
736 | while (nwrite < len) { |
---|
737 | /* |
---|
738 | * transmit character |
---|
739 | */ |
---|
740 | ns16550_polled_putchar(base, *buf++); |
---|
741 | nwrite++; |
---|
742 | } |
---|
743 | } |
---|
744 | |
---|
745 | /* |
---|
746 | * Debug gets() support |
---|
747 | */ |
---|
748 | int ns16550_polled_getchar(rtems_termios_device_context *base) |
---|
749 | { |
---|
750 | ns16550_context *ctx = (ns16550_context *) base; |
---|
751 | uint32_t pNS16550; |
---|
752 | unsigned char ucLineStatus; |
---|
753 | uint8_t cChar; |
---|
754 | ns16550_get_reg getReg; |
---|
755 | |
---|
756 | pNS16550 = ctx->port; |
---|
757 | getReg = ctx->get_reg; |
---|
758 | |
---|
759 | ucLineStatus = (*getReg)(pNS16550, NS16550_LINE_STATUS); |
---|
760 | if (ucLineStatus & SP_LSR_RDY) { |
---|
761 | cChar = (*getReg)(pNS16550, NS16550_RECEIVE_BUFFER); |
---|
762 | return (int)cChar; |
---|
763 | } |
---|
764 | return -1; |
---|
765 | } |
---|
766 | |
---|
767 | /* |
---|
768 | * Flow control is only supported when using interrupts |
---|
769 | */ |
---|
770 | |
---|
771 | const rtems_termios_device_flow ns16550_flow_rtscts = { |
---|
772 | .stop_remote_tx = ns16550_negate_RTS, |
---|
773 | .start_remote_tx = ns16550_assert_RTS |
---|
774 | }; |
---|
775 | |
---|
776 | const rtems_termios_device_flow ns16550_flow_dtrcts = { |
---|
777 | .stop_remote_tx = ns16550_negate_DTR, |
---|
778 | .start_remote_tx = ns16550_assert_DTR |
---|
779 | }; |
---|
780 | |
---|
781 | const rtems_termios_device_handler ns16550_handler_interrupt = { |
---|
782 | .first_open = ns16550_open, |
---|
783 | .last_close = ns16550_close, |
---|
784 | .poll_read = NULL, |
---|
785 | .write = ns16550_write_support_int, |
---|
786 | .set_attributes = ns16550_set_attributes, |
---|
787 | .mode = TERMIOS_IRQ_DRIVEN |
---|
788 | }; |
---|
789 | |
---|
790 | const rtems_termios_device_handler ns16550_handler_polled = { |
---|
791 | .first_open = ns16550_open, |
---|
792 | .last_close = ns16550_close, |
---|
793 | .poll_read = ns16550_polled_getchar, |
---|
794 | .write = ns16550_write_support_polled, |
---|
795 | .set_attributes = ns16550_set_attributes, |
---|
796 | .mode = TERMIOS_POLLED |
---|
797 | }; |
---|
798 | |
---|
799 | const rtems_termios_device_handler ns16550_handler_task = { |
---|
800 | .first_open = ns16550_open, |
---|
801 | .last_close = ns16550_close, |
---|
802 | .poll_read = ns16550_read_task, |
---|
803 | .write = ns16550_write_support_task, |
---|
804 | .set_attributes = ns16550_set_attributes, |
---|
805 | .mode = TERMIOS_TASK_DRIVEN |
---|
806 | }; |
---|