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 <libchip/ns16550.h> |
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40 | #include <libchip/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; |
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57 | uint32_t baudDivisor; |
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58 | uint32_t err; |
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59 | uint32_t actual; |
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60 | uint32_t newErr; |
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61 | |
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62 | if (ctx->clock != 0) { |
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63 | clock = ctx->clock; |
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64 | } else { |
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65 | clock = 115200; |
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66 | } |
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67 | |
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68 | baudDivisor = clock / (baud * 16); |
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69 | |
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70 | if (ctx->has_precision_clock_synthesizer) { |
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71 | uint32_t i; |
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72 | |
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73 | err = baud; |
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74 | baudDivisor = 0x0001ffff; |
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75 | |
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76 | for (i = 2; i <= 0x10000; i *= 2) { |
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77 | uint32_t fout; |
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78 | uint32_t fin; |
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79 | |
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80 | fin = i - 1; |
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81 | fout = (baud * fin * 16) / clock; |
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82 | actual = (clock * fout) / (16 * fin); |
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83 | newErr = actual > baud ? actual - baud : baud - actual; |
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84 | |
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85 | if (newErr < err) { |
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86 | err = newErr; |
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87 | baudDivisor = fin | (fout << 16); |
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88 | } |
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89 | } |
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90 | } else if (ctx->has_fractional_divider_register) { |
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91 | uint32_t fractionalDivider = 0x10; |
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92 | uint32_t mulVal; |
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93 | uint32_t divAddVal; |
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94 | |
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95 | err = baud; |
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96 | clock /= 16 * baudDivisor; |
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97 | |
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98 | for (mulVal = 1; mulVal < 16; ++mulVal) { |
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99 | for (divAddVal = 0; divAddVal < mulVal; ++divAddVal) { |
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100 | actual = (mulVal * clock) / (mulVal + divAddVal); |
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101 | newErr = actual > baud ? actual - baud : baud - actual; |
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102 | |
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103 | if (newErr < err) { |
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104 | err = newErr; |
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105 | fractionalDivider = (mulVal << 4) | divAddVal; |
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106 | } |
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107 | } |
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108 | } |
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109 | |
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110 | (*ctx->set_reg)( |
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111 | ctx->port, |
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112 | NS16550_FRACTIONAL_DIVIDER, |
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113 | fractionalDivider |
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114 | ); |
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115 | } else if (ctx->calculate_baud_divisor != NULL) { |
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116 | baudDivisor = ctx->calculate_baud_divisor(ctx, baud); |
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117 | } |
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118 | |
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119 | return baudDivisor; |
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120 | } |
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121 | |
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122 | /* |
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123 | * ns16550_enable_interrupts |
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124 | * |
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125 | * This routine initializes the port to have the specified interrupts masked. |
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126 | */ |
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127 | static void ns16550_enable_interrupts( |
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128 | ns16550_context *ctx, |
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129 | int mask |
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130 | ) |
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131 | { |
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132 | (*ctx->set_reg)(ctx->port, NS16550_INTERRUPT_ENABLE, mask); |
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133 | } |
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134 | |
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135 | static void ns16550_clear_and_set_interrupts( |
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136 | ns16550_context *ctx, |
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137 | uint8_t clear, |
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138 | uint8_t set |
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139 | ) |
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140 | { |
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141 | rtems_interrupt_lock_context lock_context; |
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142 | ns16550_get_reg get_reg = ctx->get_reg; |
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143 | ns16550_set_reg set_reg = ctx->set_reg; |
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144 | uintptr_t port = ctx->port; |
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145 | uint8_t val; |
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146 | |
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147 | rtems_termios_device_lock_acquire(&ctx->base, &lock_context); |
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148 | val = (*get_reg)(port, NS16550_INTERRUPT_ENABLE); |
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149 | val &= ~clear; |
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150 | val |= set; |
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151 | (*set_reg)(port, NS16550_INTERRUPT_ENABLE, val); |
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152 | rtems_termios_device_lock_release(&ctx->base, &lock_context); |
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153 | } |
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154 | |
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155 | /* |
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156 | * ns16550_probe |
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157 | */ |
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158 | |
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159 | bool ns16550_probe(rtems_termios_device_context *base) |
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160 | { |
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161 | ns16550_context *ctx = (ns16550_context *) base; |
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162 | uintptr_t pNS16550; |
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163 | uint8_t ucDataByte; |
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164 | uint32_t ulBaudDivisor; |
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165 | ns16550_set_reg setReg; |
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166 | ns16550_get_reg getReg; |
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167 | |
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168 | ctx->modem_control = SP_MODEM_IRQ; |
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169 | |
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170 | pNS16550 = ctx->port; |
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171 | setReg = ctx->set_reg; |
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172 | getReg = ctx->get_reg; |
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173 | |
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174 | /* Clear the divisor latch, clear all interrupt enables, |
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175 | * and reset and |
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176 | * disable the FIFO's. |
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177 | */ |
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178 | |
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179 | (*setReg)(pNS16550, NS16550_LINE_CONTROL, 0x0); |
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180 | ns16550_enable_interrupts(ctx, NS16550_DISABLE_ALL_INTR ); |
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181 | |
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182 | /* Set the divisor latch and set the baud rate. */ |
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183 | |
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184 | ulBaudDivisor = NS16550_GetBaudDivisor(ctx, ctx->initial_baud); |
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185 | ctx->baud_divisor = ulBaudDivisor; |
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186 | ucDataByte = SP_LINE_DLAB; |
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187 | (*setReg)(pNS16550, NS16550_LINE_CONTROL, ucDataByte); |
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188 | |
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189 | /* XXX */ |
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190 | (*setReg)(pNS16550,NS16550_DIVISOR_LATCH_L,(uint8_t)(ulBaudDivisor & 0xffU)); |
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191 | (*setReg)( |
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192 | pNS16550,NS16550_DIVISOR_LATCH_M, |
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193 | (uint8_t)(( ulBaudDivisor >> 8 ) & 0xffU ) |
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194 | ); |
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195 | |
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196 | /* Clear the divisor latch and set the character size to eight bits */ |
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197 | /* with one stop bit and no parity checking. */ |
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198 | ucDataByte = EIGHT_BITS; |
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199 | ctx->line_control = ucDataByte; |
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200 | |
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201 | if (ctx->has_precision_clock_synthesizer) { |
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202 | uint8_t fcr; |
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203 | |
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204 | /* |
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205 | * Enable precision clock synthesizer. This must be done with DLAB == 1 in |
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206 | * the line control register. |
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207 | */ |
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208 | fcr = (*getReg)(pNS16550, NS16550_FIFO_CONTROL ); |
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209 | fcr |= 0x10; |
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210 | (*setReg)(pNS16550, NS16550_FIFO_CONTROL, fcr); |
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211 | |
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212 | (*setReg)(pNS16550, NS16550_SCRATCH_PAD, (uint8_t)(ulBaudDivisor >> 24)); |
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213 | (*setReg)(pNS16550, NS16550_LINE_CONTROL, ucDataByte ); |
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214 | (*setReg)(pNS16550, NS16550_SCRATCH_PAD, (uint8_t)(ulBaudDivisor >> 16)); |
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215 | } else { |
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216 | (*setReg)(pNS16550, NS16550_LINE_CONTROL, ucDataByte); |
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217 | } |
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218 | |
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219 | /* Enable and reset transmit and receive FIFOs. TJA */ |
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220 | ucDataByte = SP_FIFO_ENABLE; |
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221 | (*setReg)(pNS16550, NS16550_FIFO_CONTROL, ucDataByte); |
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222 | |
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223 | ucDataByte = SP_FIFO_ENABLE | SP_FIFO_RXRST | SP_FIFO_TXRST; |
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224 | (*setReg)(pNS16550, NS16550_FIFO_CONTROL, ucDataByte); |
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225 | |
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226 | ns16550_enable_interrupts(ctx, NS16550_DISABLE_ALL_INTR); |
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227 | |
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228 | /* Set data terminal ready. */ |
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229 | /* And open interrupt tristate line */ |
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230 | (*setReg)(pNS16550, NS16550_MODEM_CONTROL,ctx->modem_control); |
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231 | |
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232 | (*getReg)(pNS16550, NS16550_LINE_STATUS ); |
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233 | (*getReg)(pNS16550, NS16550_RECEIVE_BUFFER ); |
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234 | |
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235 | return true; |
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236 | } |
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237 | |
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238 | static size_t ns16550_write_to_fifo( |
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239 | const ns16550_context *ctx, |
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240 | const char *buf, |
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241 | size_t len |
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242 | ) |
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243 | { |
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244 | uintptr_t port = ctx->port; |
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245 | ns16550_set_reg set = ctx->set_reg; |
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246 | size_t out = len > SP_FIFO_SIZE ? SP_FIFO_SIZE : len; |
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247 | size_t i; |
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248 | |
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249 | for (i = 0; i < out; ++i) { |
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250 | (*set)(port, NS16550_TRANSMIT_BUFFER, buf[i]); |
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251 | } |
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252 | |
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253 | return out; |
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254 | } |
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255 | |
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256 | /** |
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257 | * @brief Process interrupt. |
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258 | */ |
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259 | static void ns16550_isr(void *arg) |
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260 | { |
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261 | rtems_termios_tty *tty = arg; |
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262 | ns16550_context *ctx = rtems_termios_get_device_context(tty); |
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263 | uintptr_t port = ctx->port; |
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264 | ns16550_get_reg get = ctx->get_reg; |
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265 | int i = 0; |
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266 | char buf [SP_FIFO_SIZE]; |
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267 | |
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268 | /* Iterate until no more interrupts are pending */ |
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269 | do { |
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270 | /* Fetch received characters */ |
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271 | for (i = 0; i < SP_FIFO_SIZE; ++i) { |
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272 | if ((get( port, NS16550_LINE_STATUS) & SP_LSR_RDY) != 0) { |
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273 | buf [i] = (char) get(port, NS16550_RECEIVE_BUFFER); |
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274 | } else { |
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275 | break; |
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276 | } |
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277 | } |
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278 | |
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279 | /* Enqueue fetched characters */ |
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280 | rtems_termios_enqueue_raw_characters(tty, buf, i); |
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281 | |
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282 | /* Do transmit */ |
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283 | if (ctx->out_total > 0 |
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284 | && (get(port, NS16550_LINE_STATUS) & SP_LSR_THOLD) != 0) { |
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285 | size_t current = ctx->out_current; |
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286 | |
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287 | ctx->out_buf += current; |
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288 | ctx->out_remaining -= current; |
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289 | |
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290 | if (ctx->out_remaining > 0) { |
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291 | ctx->out_current = |
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292 | ns16550_write_to_fifo(ctx, ctx->out_buf, ctx->out_remaining); |
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293 | } else { |
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294 | rtems_termios_dequeue_characters(tty, ctx->out_total); |
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295 | } |
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296 | } |
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297 | } while ((get( port, NS16550_INTERRUPT_ID) & SP_IID_0) == 0); |
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298 | } |
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299 | |
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300 | static void ns16550_isr_task(void *arg) |
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301 | { |
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302 | rtems_termios_tty *tty = arg; |
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303 | ns16550_context *ctx = rtems_termios_get_device_context(tty); |
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304 | uint8_t status = (*ctx->get_reg)(ctx->port, NS16550_LINE_STATUS); |
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305 | |
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306 | if ((status & SP_LSR_RDY) != 0) { |
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307 | ns16550_clear_and_set_interrupts(ctx, SP_INT_RX_ENABLE, 0); |
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308 | rtems_termios_rxirq_occured(tty); |
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309 | } |
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310 | |
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311 | if (ctx->out_total > 0 && (status & SP_LSR_THOLD) != 0) { |
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312 | size_t current = ctx->out_current; |
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313 | |
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314 | ctx->out_buf += current; |
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315 | ctx->out_remaining -= current; |
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316 | |
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317 | if (ctx->out_remaining > 0) { |
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318 | ctx->out_current = |
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319 | ns16550_write_to_fifo(ctx, ctx->out_buf, ctx->out_remaining); |
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320 | } else { |
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321 | size_t done = ctx->out_total; |
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322 | |
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323 | ctx->out_total = 0; |
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324 | ns16550_clear_and_set_interrupts(ctx, SP_INT_TX_ENABLE, 0); |
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325 | rtems_termios_dequeue_characters(tty, done); |
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326 | } |
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327 | } |
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328 | } |
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329 | |
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330 | static int ns16550_read_task(rtems_termios_device_context *base) |
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331 | { |
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332 | ns16550_context *ctx = (ns16550_context *) base; |
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333 | uintptr_t port = ctx->port; |
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334 | ns16550_get_reg get = ctx->get_reg; |
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335 | char buf[SP_FIFO_SIZE]; |
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336 | int i; |
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337 | |
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338 | for (i = 0; i < SP_FIFO_SIZE; ++i) { |
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339 | if ((get(port, NS16550_LINE_STATUS) & SP_LSR_RDY) != 0) { |
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340 | buf[i] = (char) get(port, NS16550_RECEIVE_BUFFER); |
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341 | } else { |
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342 | break; |
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343 | } |
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344 | } |
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345 | |
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346 | rtems_termios_enqueue_raw_characters(ctx->tty, buf, i); |
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347 | ns16550_clear_and_set_interrupts(ctx, 0, SP_INT_RX_ENABLE); |
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348 | |
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349 | return -1; |
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350 | } |
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351 | |
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352 | /* |
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353 | * ns16550_initialize_interrupts |
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354 | * |
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355 | * This routine initializes the port to operate in interrupt driver mode. |
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356 | */ |
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357 | static void ns16550_initialize_interrupts( |
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358 | struct rtems_termios_tty *tty, |
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359 | ns16550_context *ctx, |
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360 | void (*isr)(void *) |
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361 | ) |
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362 | { |
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363 | #ifdef BSP_FEATURE_IRQ_EXTENSION |
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364 | { |
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365 | rtems_status_code sc = RTEMS_SUCCESSFUL; |
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366 | sc = rtems_interrupt_handler_install( |
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367 | ctx->irq, |
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368 | "NS16550", |
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369 | RTEMS_INTERRUPT_SHARED, |
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370 | isr, |
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371 | tty |
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372 | ); |
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373 | if (sc != RTEMS_SUCCESSFUL) { |
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374 | /* FIXME */ |
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375 | printk( "%s: Error: Install interrupt handler\n", __func__); |
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376 | rtems_fatal_error_occurred( 0xdeadbeef); |
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377 | } |
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378 | } |
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379 | #elif defined(BSP_FEATURE_IRQ_LEGACY) |
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380 | { |
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381 | int rv = 0; |
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382 | #ifdef BSP_FEATURE_IRQ_LEGACY_SHARED_HANDLER_SUPPORT |
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383 | rtems_irq_connect_data cd = { |
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384 | ctx->irq, |
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385 | isr, |
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386 | tty, |
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387 | NULL, |
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388 | NULL, |
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389 | NULL, |
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390 | NULL |
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391 | }; |
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392 | rv = BSP_install_rtems_shared_irq_handler( &cd); |
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393 | #else |
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394 | rtems_irq_connect_data cd = { |
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395 | ctx->irq, |
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396 | isr, |
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397 | tty, |
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398 | NULL, |
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399 | NULL, |
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400 | NULL |
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401 | }; |
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402 | rv = BSP_install_rtems_irq_handler( &cd); |
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403 | #endif |
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404 | if (rv == 0) { |
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405 | /* FIXME */ |
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406 | printk( "%s: Error: Install interrupt handler\n", __func__); |
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407 | rtems_fatal_error_occurred( 0xdeadbeef); |
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408 | } |
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409 | } |
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410 | #endif |
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411 | } |
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412 | |
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413 | /* |
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414 | * ns16550_open |
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415 | */ |
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416 | |
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417 | static bool ns16550_open( |
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418 | struct rtems_termios_tty *tty, |
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419 | rtems_termios_device_context *base, |
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420 | struct termios *term, |
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421 | rtems_libio_open_close_args_t *args |
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422 | ) |
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423 | { |
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424 | ns16550_context *ctx = (ns16550_context *) base; |
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425 | |
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426 | ctx->tty = tty; |
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427 | |
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428 | /* Set initial baud */ |
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429 | rtems_termios_set_initial_baud(tty, ctx->initial_baud); |
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430 | |
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431 | if (tty->handler.mode == TERMIOS_IRQ_DRIVEN) { |
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432 | ns16550_initialize_interrupts(tty, ctx, ns16550_isr); |
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433 | ns16550_enable_interrupts(ctx, NS16550_ENABLE_ALL_INTR_EXCEPT_TX); |
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434 | } else if (tty->handler.mode == TERMIOS_TASK_DRIVEN) { |
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435 | ns16550_initialize_interrupts(tty, ctx, ns16550_isr_task); |
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436 | ns16550_enable_interrupts(ctx, NS16550_ENABLE_ALL_INTR_EXCEPT_TX); |
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437 | } |
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438 | |
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439 | return true; |
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440 | } |
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441 | |
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442 | static void ns16550_cleanup_interrupts( |
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443 | struct rtems_termios_tty *tty, |
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444 | ns16550_context *ctx, |
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445 | void (*isr)(void *) |
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446 | ) |
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447 | { |
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448 | #if defined(BSP_FEATURE_IRQ_EXTENSION) |
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449 | rtems_status_code sc = RTEMS_SUCCESSFUL; |
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450 | sc = rtems_interrupt_handler_remove( |
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451 | ctx->irq, |
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452 | isr, |
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453 | tty |
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454 | ); |
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455 | if (sc != RTEMS_SUCCESSFUL) { |
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456 | /* FIXME */ |
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457 | printk("%s: Error: Remove interrupt handler\n", __func__); |
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458 | rtems_fatal_error_occurred(0xdeadbeef); |
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459 | } |
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460 | #elif defined(BSP_FEATURE_IRQ_LEGACY) |
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461 | int rv = 0; |
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462 | rtems_irq_connect_data cd = { |
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463 | .name = ctx->irq, |
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464 | .hdl = isr, |
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465 | .handle = tty |
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466 | }; |
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467 | rv = BSP_remove_rtems_irq_handler(&cd); |
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468 | if (rv == 0) { |
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469 | /* FIXME */ |
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470 | printk("%s: Error: Remove interrupt handler\n", __func__); |
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471 | rtems_fatal_error_occurred(0xdeadbeef); |
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472 | } |
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473 | #endif |
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474 | } |
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475 | |
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476 | /* |
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477 | * ns16550_close |
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478 | */ |
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479 | |
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480 | static void ns16550_close( |
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481 | struct rtems_termios_tty *tty, |
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482 | rtems_termios_device_context *base, |
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483 | rtems_libio_open_close_args_t *args |
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484 | ) |
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485 | { |
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486 | ns16550_context *ctx = (ns16550_context *) base; |
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487 | |
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488 | ns16550_enable_interrupts(ctx, NS16550_DISABLE_ALL_INTR); |
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489 | |
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490 | if (tty->handler.mode == TERMIOS_IRQ_DRIVEN) { |
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491 | ns16550_cleanup_interrupts(tty, ctx, ns16550_isr); |
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492 | } else if (tty->handler.mode == TERMIOS_TASK_DRIVEN) { |
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493 | ns16550_cleanup_interrupts(tty, ctx, ns16550_isr_task); |
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494 | } |
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495 | } |
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496 | |
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497 | /** |
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498 | * @brief Polled write for NS16550. |
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499 | */ |
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500 | void ns16550_polled_putchar(rtems_termios_device_context *base, char out) |
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501 | { |
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502 | ns16550_context *ctx = (ns16550_context *) base; |
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503 | uintptr_t port = ctx->port; |
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504 | ns16550_get_reg get = ctx->get_reg; |
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505 | ns16550_set_reg set = ctx->set_reg; |
---|
506 | uint32_t status = 0; |
---|
507 | rtems_interrupt_lock_context lock_context; |
---|
508 | |
---|
509 | /* Save port interrupt mask */ |
---|
510 | uint32_t interrupt_mask = get( port, NS16550_INTERRUPT_ENABLE); |
---|
511 | |
---|
512 | /* Disable port interrupts */ |
---|
513 | ns16550_enable_interrupts(ctx, NS16550_DISABLE_ALL_INTR); |
---|
514 | |
---|
515 | while (true) { |
---|
516 | /* Try to transmit the character in a critical section */ |
---|
517 | rtems_termios_device_lock_acquire(&ctx->base, &lock_context); |
---|
518 | |
---|
519 | /* Read the transmitter holding register and check it */ |
---|
520 | status = get( port, NS16550_LINE_STATUS); |
---|
521 | if ((status & SP_LSR_THOLD) != 0) { |
---|
522 | /* Transmit character */ |
---|
523 | set( port, NS16550_TRANSMIT_BUFFER, out); |
---|
524 | |
---|
525 | /* Finished */ |
---|
526 | rtems_termios_device_lock_release(&ctx->base, &lock_context); |
---|
527 | break; |
---|
528 | } else { |
---|
529 | rtems_termios_device_lock_release(&ctx->base, &lock_context); |
---|
530 | } |
---|
531 | |
---|
532 | /* Wait for transmitter holding register to be empty */ |
---|
533 | do { |
---|
534 | status = get( port, NS16550_LINE_STATUS); |
---|
535 | } while ((status & SP_LSR_THOLD) == 0); |
---|
536 | } |
---|
537 | |
---|
538 | /* Restore port interrupt mask */ |
---|
539 | set( port, NS16550_INTERRUPT_ENABLE, interrupt_mask); |
---|
540 | } |
---|
541 | |
---|
542 | /* |
---|
543 | * These routines provide control of the RTS and DTR lines |
---|
544 | */ |
---|
545 | |
---|
546 | /* |
---|
547 | * ns16550_assert_RTS |
---|
548 | */ |
---|
549 | |
---|
550 | static void ns16550_assert_RTS(rtems_termios_device_context *base) |
---|
551 | { |
---|
552 | ns16550_context *ctx = (ns16550_context *) base; |
---|
553 | rtems_interrupt_lock_context lock_context; |
---|
554 | |
---|
555 | /* |
---|
556 | * Assert RTS |
---|
557 | */ |
---|
558 | rtems_termios_device_lock_acquire(base, &lock_context); |
---|
559 | ctx->modem_control |= SP_MODEM_RTS; |
---|
560 | (*ctx->set_reg)(ctx->port, NS16550_MODEM_CONTROL, ctx->modem_control); |
---|
561 | rtems_termios_device_lock_release(base, &lock_context); |
---|
562 | } |
---|
563 | |
---|
564 | /* |
---|
565 | * ns16550_negate_RTS |
---|
566 | */ |
---|
567 | |
---|
568 | static void ns16550_negate_RTS(rtems_termios_device_context *base) |
---|
569 | { |
---|
570 | ns16550_context *ctx = (ns16550_context *) base; |
---|
571 | rtems_interrupt_lock_context lock_context; |
---|
572 | |
---|
573 | /* |
---|
574 | * Negate RTS |
---|
575 | */ |
---|
576 | rtems_termios_device_lock_acquire(base, &lock_context); |
---|
577 | ctx->modem_control &= ~SP_MODEM_RTS; |
---|
578 | (*ctx->set_reg)(ctx->port, NS16550_MODEM_CONTROL, ctx->modem_control); |
---|
579 | rtems_termios_device_lock_release(base, &lock_context); |
---|
580 | } |
---|
581 | |
---|
582 | /* |
---|
583 | * These flow control routines utilise a connection from the local DTR |
---|
584 | * line to the remote CTS line |
---|
585 | */ |
---|
586 | |
---|
587 | /* |
---|
588 | * ns16550_assert_DTR |
---|
589 | */ |
---|
590 | |
---|
591 | static void ns16550_assert_DTR(rtems_termios_device_context *base) |
---|
592 | { |
---|
593 | ns16550_context *ctx = (ns16550_context *) base; |
---|
594 | rtems_interrupt_lock_context lock_context; |
---|
595 | |
---|
596 | /* |
---|
597 | * Assert DTR |
---|
598 | */ |
---|
599 | rtems_termios_device_lock_acquire(base, &lock_context); |
---|
600 | ctx->modem_control |= SP_MODEM_DTR; |
---|
601 | (*ctx->set_reg)(ctx->port, NS16550_MODEM_CONTROL, ctx->modem_control); |
---|
602 | rtems_termios_device_lock_release(base, &lock_context); |
---|
603 | } |
---|
604 | |
---|
605 | /* |
---|
606 | * ns16550_negate_DTR |
---|
607 | */ |
---|
608 | |
---|
609 | static void ns16550_negate_DTR(rtems_termios_device_context *base) |
---|
610 | { |
---|
611 | ns16550_context *ctx = (ns16550_context *) base; |
---|
612 | rtems_interrupt_lock_context lock_context; |
---|
613 | |
---|
614 | /* |
---|
615 | * Negate DTR |
---|
616 | */ |
---|
617 | rtems_termios_device_lock_acquire(base, &lock_context); |
---|
618 | ctx->modem_control &=~SP_MODEM_DTR; |
---|
619 | (*ctx->set_reg)(ctx->port, NS16550_MODEM_CONTROL,ctx->modem_control); |
---|
620 | rtems_termios_device_lock_release(base, &lock_context); |
---|
621 | } |
---|
622 | |
---|
623 | /* |
---|
624 | * ns16550_set_attributes |
---|
625 | * |
---|
626 | * This function sets the channel to reflect the requested termios |
---|
627 | * port settings. |
---|
628 | */ |
---|
629 | |
---|
630 | static bool ns16550_set_attributes( |
---|
631 | rtems_termios_device_context *base, |
---|
632 | const struct termios *t |
---|
633 | ) |
---|
634 | { |
---|
635 | ns16550_context *ctx = (ns16550_context *) base; |
---|
636 | uint32_t pNS16550; |
---|
637 | uint32_t ulBaudDivisor; |
---|
638 | uint8_t ucLineControl; |
---|
639 | uint32_t baud_requested; |
---|
640 | ns16550_set_reg setReg; |
---|
641 | |
---|
642 | pNS16550 = ctx->port; |
---|
643 | setReg = ctx->set_reg; |
---|
644 | |
---|
645 | /* |
---|
646 | * Calculate the baud rate divisor |
---|
647 | * |
---|
648 | * Assert ensures there is no division by 0. |
---|
649 | */ |
---|
650 | |
---|
651 | baud_requested = rtems_termios_baud_to_number(t->c_ospeed); |
---|
652 | _Assert( baud_requested != 0 ); |
---|
653 | |
---|
654 | ulBaudDivisor = NS16550_GetBaudDivisor(ctx, baud_requested); |
---|
655 | |
---|
656 | ucLineControl = 0; |
---|
657 | |
---|
658 | /* |
---|
659 | * Parity |
---|
660 | */ |
---|
661 | |
---|
662 | if (t->c_cflag & PARENB) { |
---|
663 | ucLineControl |= SP_LINE_PAR; |
---|
664 | if (!(t->c_cflag & PARODD)) |
---|
665 | ucLineControl |= SP_LINE_ODD; |
---|
666 | } |
---|
667 | |
---|
668 | /* |
---|
669 | * Character Size |
---|
670 | */ |
---|
671 | |
---|
672 | if (t->c_cflag & CSIZE) { |
---|
673 | switch (t->c_cflag & CSIZE) { |
---|
674 | case CS5: ucLineControl |= FIVE_BITS; break; |
---|
675 | case CS6: ucLineControl |= SIX_BITS; break; |
---|
676 | case CS7: ucLineControl |= SEVEN_BITS; break; |
---|
677 | case CS8: ucLineControl |= EIGHT_BITS; break; |
---|
678 | } |
---|
679 | } else { |
---|
680 | ucLineControl |= EIGHT_BITS; /* default to 9600,8,N,1 */ |
---|
681 | } |
---|
682 | |
---|
683 | /* |
---|
684 | * Stop Bits |
---|
685 | */ |
---|
686 | |
---|
687 | if (t->c_cflag & CSTOPB) { |
---|
688 | ucLineControl |= SP_LINE_STOP; /* 2 stop bits */ |
---|
689 | } else { |
---|
690 | ; /* 1 stop bit */ |
---|
691 | } |
---|
692 | |
---|
693 | /* |
---|
694 | * Now actually set the chip |
---|
695 | */ |
---|
696 | |
---|
697 | if (ulBaudDivisor != ctx->baud_divisor || ucLineControl != ctx->line_control) { |
---|
698 | rtems_interrupt_lock_context lock_context; |
---|
699 | |
---|
700 | ctx->baud_divisor = ulBaudDivisor; |
---|
701 | ctx->line_control = ucLineControl; |
---|
702 | |
---|
703 | rtems_termios_device_lock_acquire(base, &lock_context); |
---|
704 | |
---|
705 | /* |
---|
706 | * Set the baud rate |
---|
707 | * |
---|
708 | * NOTE: When the Divisor Latch Access Bit (DLAB) is set to 1, |
---|
709 | * the transmit buffer and interrupt enable registers |
---|
710 | * turn into the LSB and MSB divisor latch registers. |
---|
711 | */ |
---|
712 | |
---|
713 | (*setReg)(pNS16550, NS16550_LINE_CONTROL, SP_LINE_DLAB); |
---|
714 | (*setReg)(pNS16550, NS16550_DIVISOR_LATCH_L, ulBaudDivisor&0xff); |
---|
715 | (*setReg)(pNS16550, NS16550_DIVISOR_LATCH_M, (ulBaudDivisor>>8)&0xff); |
---|
716 | |
---|
717 | /* |
---|
718 | * Now write the line control |
---|
719 | */ |
---|
720 | if (ctx->has_precision_clock_synthesizer) { |
---|
721 | (*setReg)(pNS16550, NS16550_SCRATCH_PAD, (uint8_t)(ulBaudDivisor >> 24)); |
---|
722 | (*setReg)(pNS16550, NS16550_LINE_CONTROL, ucLineControl ); |
---|
723 | (*setReg)(pNS16550, NS16550_SCRATCH_PAD, (uint8_t)(ulBaudDivisor >> 16)); |
---|
724 | } else { |
---|
725 | (*setReg)(pNS16550, NS16550_LINE_CONTROL, ucLineControl ); |
---|
726 | } |
---|
727 | |
---|
728 | rtems_termios_device_lock_release(base, &lock_context); |
---|
729 | } |
---|
730 | |
---|
731 | return true; |
---|
732 | } |
---|
733 | |
---|
734 | /** |
---|
735 | * @brief Transmits up to @a len characters from @a buf. |
---|
736 | * |
---|
737 | * This routine is invoked either from task context with disabled interrupts to |
---|
738 | * start a new transmission process with exactly one character in case of an |
---|
739 | * idle output state or from the interrupt handler to refill the transmitter. |
---|
740 | * |
---|
741 | * Returns always zero. |
---|
742 | */ |
---|
743 | static void ns16550_write_support_int( |
---|
744 | rtems_termios_device_context *base, |
---|
745 | const char *buf, |
---|
746 | size_t len |
---|
747 | ) |
---|
748 | { |
---|
749 | ns16550_context *ctx = (ns16550_context *) base; |
---|
750 | |
---|
751 | ctx->out_total = len; |
---|
752 | |
---|
753 | if (len > 0) { |
---|
754 | ctx->out_remaining = len; |
---|
755 | ctx->out_buf = buf; |
---|
756 | ctx->out_current = ns16550_write_to_fifo(ctx, buf, len); |
---|
757 | |
---|
758 | ns16550_enable_interrupts(ctx, NS16550_ENABLE_ALL_INTR); |
---|
759 | } else { |
---|
760 | ns16550_enable_interrupts(ctx, NS16550_ENABLE_ALL_INTR_EXCEPT_TX); |
---|
761 | } |
---|
762 | } |
---|
763 | |
---|
764 | static void ns16550_write_support_task( |
---|
765 | rtems_termios_device_context *base, |
---|
766 | const char *buf, |
---|
767 | size_t len |
---|
768 | ) |
---|
769 | { |
---|
770 | ns16550_context *ctx = (ns16550_context *) base; |
---|
771 | |
---|
772 | ctx->out_total = len; |
---|
773 | |
---|
774 | if (len > 0) { |
---|
775 | ctx->out_remaining = len; |
---|
776 | ctx->out_buf = buf; |
---|
777 | ctx->out_current = ns16550_write_to_fifo(ctx, buf, len); |
---|
778 | |
---|
779 | ns16550_clear_and_set_interrupts(ctx, 0, SP_INT_TX_ENABLE); |
---|
780 | } |
---|
781 | } |
---|
782 | |
---|
783 | /* |
---|
784 | * ns16550_write_support_polled |
---|
785 | * |
---|
786 | * Console Termios output entry point. |
---|
787 | * |
---|
788 | */ |
---|
789 | |
---|
790 | static void ns16550_write_support_polled( |
---|
791 | rtems_termios_device_context *base, |
---|
792 | const char *buf, |
---|
793 | size_t len |
---|
794 | ) |
---|
795 | { |
---|
796 | size_t nwrite = 0; |
---|
797 | |
---|
798 | /* |
---|
799 | * poll each byte in the string out of the port. |
---|
800 | */ |
---|
801 | while (nwrite < len) { |
---|
802 | /* |
---|
803 | * transmit character |
---|
804 | */ |
---|
805 | ns16550_polled_putchar(base, *buf++); |
---|
806 | nwrite++; |
---|
807 | } |
---|
808 | } |
---|
809 | |
---|
810 | /* |
---|
811 | * Debug gets() support |
---|
812 | */ |
---|
813 | int ns16550_polled_getchar(rtems_termios_device_context *base) |
---|
814 | { |
---|
815 | ns16550_context *ctx = (ns16550_context *) base; |
---|
816 | uint32_t pNS16550; |
---|
817 | unsigned char ucLineStatus; |
---|
818 | uint8_t cChar; |
---|
819 | ns16550_get_reg getReg; |
---|
820 | |
---|
821 | pNS16550 = ctx->port; |
---|
822 | getReg = ctx->get_reg; |
---|
823 | |
---|
824 | ucLineStatus = (*getReg)(pNS16550, NS16550_LINE_STATUS); |
---|
825 | if (ucLineStatus & SP_LSR_RDY) { |
---|
826 | cChar = (*getReg)(pNS16550, NS16550_RECEIVE_BUFFER); |
---|
827 | return (int)cChar; |
---|
828 | } |
---|
829 | return -1; |
---|
830 | } |
---|
831 | |
---|
832 | /* |
---|
833 | * Flow control is only supported when using interrupts |
---|
834 | */ |
---|
835 | |
---|
836 | const rtems_termios_device_flow ns16550_flow_rtscts = { |
---|
837 | .stop_remote_tx = ns16550_negate_RTS, |
---|
838 | .start_remote_tx = ns16550_assert_RTS |
---|
839 | }; |
---|
840 | |
---|
841 | const rtems_termios_device_flow ns16550_flow_dtrcts = { |
---|
842 | .stop_remote_tx = ns16550_negate_DTR, |
---|
843 | .start_remote_tx = ns16550_assert_DTR |
---|
844 | }; |
---|
845 | |
---|
846 | const rtems_termios_device_handler ns16550_handler_interrupt = { |
---|
847 | .first_open = ns16550_open, |
---|
848 | .last_close = ns16550_close, |
---|
849 | .poll_read = NULL, |
---|
850 | .write = ns16550_write_support_int, |
---|
851 | .set_attributes = ns16550_set_attributes, |
---|
852 | .mode = TERMIOS_IRQ_DRIVEN |
---|
853 | }; |
---|
854 | |
---|
855 | const rtems_termios_device_handler ns16550_handler_polled = { |
---|
856 | .first_open = ns16550_open, |
---|
857 | .last_close = ns16550_close, |
---|
858 | .poll_read = ns16550_polled_getchar, |
---|
859 | .write = ns16550_write_support_polled, |
---|
860 | .set_attributes = ns16550_set_attributes, |
---|
861 | .mode = TERMIOS_POLLED |
---|
862 | }; |
---|
863 | |
---|
864 | const rtems_termios_device_handler ns16550_handler_task = { |
---|
865 | .first_open = ns16550_open, |
---|
866 | .last_close = ns16550_close, |
---|
867 | .poll_read = ns16550_read_task, |
---|
868 | .write = ns16550_write_support_task, |
---|
869 | .set_attributes = ns16550_set_attributes, |
---|
870 | .mode = TERMIOS_TASK_DRIVEN |
---|
871 | }; |
---|