1 | /* framebuffer.c |
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2 | * |
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3 | * This file is the framebuffer driver for the Milkymist VGA IP-core |
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4 | * This VGA Core is a part of Milkymist System-on-Chip |
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5 | * |
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6 | * The license and distribution terms for this file may be |
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7 | * found in the file LICENSE in this distribution or at |
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8 | * http://www.rtems.com/license/LICENSE. |
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9 | * |
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10 | * $Id$ |
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11 | * |
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12 | * COPYRIGHT (c) Yann Sionneau <yann.sionneau@telecom-sudparis.eu> (GSoC 2010) |
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13 | * Telecom SudParis |
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14 | */ |
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15 | |
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16 | #include <stdlib.h> |
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17 | #include <stdio.h> |
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18 | #include <errno.h> |
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19 | #include <sys/types.h> |
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20 | #include <pthread.h> |
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21 | #include <rtems.h> |
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22 | #include <bsp.h> |
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23 | #include "../include/system_conf.h" |
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24 | #include <rtems/libio.h> |
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25 | #include <rtems/fb.h> |
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26 | |
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27 | #define FRAMEBUFFER_DEVICE_NAME "/dev/fb" |
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28 | |
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29 | pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER; |
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30 | |
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31 | static unsigned short int framebufferA[640*480] __attribute__((aligned(32))); |
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32 | static unsigned short int framebufferB[640*480] __attribute__((aligned(32))); |
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33 | static unsigned short int framebufferC[640*480] __attribute__((aligned(32))); |
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34 | |
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35 | static unsigned short int *frontbuffer = framebufferA; |
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36 | static unsigned short int *backbuffer = framebufferB; |
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37 | static unsigned short int *lastbuffer = framebufferC; |
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38 | |
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39 | static inline void fb_write(unsigned int reg, int value) |
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40 | { |
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41 | *((int*)reg) = value; |
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42 | } |
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43 | |
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44 | static inline int fb_read(unsigned int reg) |
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45 | { |
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46 | return *((int*)(reg)); |
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47 | } |
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48 | |
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49 | /* screen information for the VGA driver */ |
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50 | static struct fb_var_screeninfo fb_var = |
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51 | { |
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52 | .xres = 640, |
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53 | .yres = 480, |
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54 | .bits_per_pixel = 16 |
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55 | }; |
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56 | |
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57 | static struct fb_fix_screeninfo fb_fix = |
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58 | { |
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59 | // this is initialized at start-up |
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60 | .smem_len = 640 * 480 * 2, /* buffer size */ |
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61 | // 2 bytes per pixels |
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62 | .type = FB_TYPE_VGA_PLANES, /* type of display */ |
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63 | .visual = FB_VISUAL_TRUECOLOR, /* color scheme used */ |
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64 | .line_length = 80 /* chars per line */ |
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65 | }; |
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66 | |
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67 | |
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68 | static int get_fix_screen_info( struct fb_fix_screeninfo *info ) |
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69 | { |
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70 | *info = fb_fix; |
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71 | return 0; |
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72 | } |
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73 | |
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74 | static int get_var_screen_info( struct fb_var_screeninfo *info ) |
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75 | { |
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76 | *info = fb_var; |
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77 | return 0; |
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78 | } |
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79 | |
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80 | |
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81 | rtems_device_driver frame_buffer_initialize( |
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82 | rtems_device_major_number major, |
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83 | rtems_device_minor_number minor, |
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84 | void *arg) |
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85 | { |
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86 | rtems_status_code status; |
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87 | |
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88 | printk( "frame buffer driver initializing..\n" ); |
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89 | |
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90 | fb_fix.smem_start = (volatile char *)frontbuffer; |
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91 | |
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92 | fb_write(MM_VGA_BASEADDRESS, (unsigned int)frontbuffer); |
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93 | fb_write(MM_VGA_RESET, (unsigned int)0); |
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94 | |
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95 | /* |
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96 | * Register the device |
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97 | */ |
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98 | status = rtems_io_register_name(FRAMEBUFFER_DEVICE_NAME, major, 0); |
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99 | if (status != RTEMS_SUCCESSFUL) |
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100 | { |
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101 | printk("Error registering frame buffer device!\n"); |
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102 | rtems_fatal_error_occurred( status ); |
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103 | } |
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104 | |
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105 | printk("VGA: initialized at resolution %dx%d\n", fb_var.xres, fb_var.yres); |
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106 | printk("VGA: framebuffers at 0x%08x 0x%08x 0x%08x\n", |
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107 | (unsigned int)frontbuffer, (unsigned int)backbuffer, |
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108 | (unsigned int)lastbuffer); |
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109 | |
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110 | /* |
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111 | * graphics hardware initialization goes here for non-console |
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112 | * devices |
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113 | */ |
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114 | return RTEMS_SUCCESSFUL; |
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115 | } |
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116 | |
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117 | rtems_device_driver frame_buffer_close( |
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118 | rtems_device_major_number major, |
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119 | rtems_device_minor_number minor, |
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120 | void *arg |
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121 | ) |
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122 | { |
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123 | if (pthread_mutex_unlock(&mutex) == 0){ |
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124 | /* restore previous state. for VGA this means return to text mode. |
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125 | * leave out if graphics hardware has been initialized in |
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126 | * frame_buffer_initialize() */ |
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127 | fb_write(MM_VGA_RESET, MM_VGA_RESET_MODE); |
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128 | return RTEMS_SUCCESSFUL; |
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129 | } |
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130 | return RTEMS_UNSATISFIED; |
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131 | } |
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132 | |
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133 | rtems_device_driver frame_buffer_open( |
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134 | rtems_device_major_number major, |
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135 | rtems_device_minor_number minor, |
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136 | void *arg |
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137 | ) |
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138 | { |
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139 | if (pthread_mutex_trylock(&mutex) == 0){ |
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140 | fb_write(MM_VGA_RESET, (unsigned int)0); |
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141 | return RTEMS_SUCCESSFUL; |
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142 | } |
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143 | return RTEMS_UNSATISFIED; |
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144 | } |
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145 | |
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146 | static void vga_swap_buffers(void) |
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147 | { |
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148 | unsigned short int *p; |
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149 | |
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150 | /* |
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151 | * Make sure last buffer swap has been executed. |
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152 | * Beware, DMA address registers of vgafb are incomplete |
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153 | * (only LSBs are present) so don't compare them directly |
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154 | * with CPU pointers. |
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155 | */ |
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156 | while( fb_read(MM_VGA_BASEADDRESS_ACT) != fb_read(MM_VGA_BASEADDRESS) ); |
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157 | |
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158 | p = frontbuffer; |
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159 | frontbuffer = backbuffer; |
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160 | backbuffer = lastbuffer; |
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161 | lastbuffer = p; |
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162 | |
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163 | fb_fix.smem_start = (volatile char *)backbuffer; |
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164 | |
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165 | fb_write(MM_VGA_BASEADDRESS, (unsigned int)frontbuffer); |
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166 | } |
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167 | |
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168 | rtems_device_driver frame_buffer_read( |
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169 | rtems_device_major_number major, |
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170 | rtems_device_minor_number minor, |
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171 | void *arg |
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172 | ) |
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173 | { |
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174 | rtems_libio_rw_args_t *rw_args = (rtems_libio_rw_args_t *)arg; |
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175 | rw_args->bytes_moved = ((rw_args->offset + rw_args->count) > fb_fix.smem_len ) ? (fb_fix.smem_len - rw_args->offset) : rw_args->count; |
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176 | memcpy(rw_args->buffer, (const void *) (fb_fix.smem_start + rw_args->offset), rw_args->bytes_moved); |
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177 | return RTEMS_SUCCESSFUL; |
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178 | } |
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179 | |
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180 | rtems_device_driver frame_buffer_write( |
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181 | rtems_device_major_number major, |
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182 | rtems_device_minor_number minor, |
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183 | void *arg |
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184 | ) |
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185 | { |
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186 | rtems_libio_rw_args_t *rw_args = (rtems_libio_rw_args_t *)arg; |
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187 | rw_args->bytes_moved = ((rw_args->offset + rw_args->count) > fb_fix.smem_len ) ? (fb_fix.smem_len - rw_args->offset) : rw_args->count; |
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188 | memcpy( (void *) (fb_fix.smem_start + rw_args->offset), rw_args->buffer, rw_args->bytes_moved); |
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189 | return RTEMS_SUCCESSFUL; |
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190 | } |
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191 | |
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192 | rtems_device_driver frame_buffer_control( |
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193 | rtems_device_major_number major, |
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194 | rtems_device_minor_number minor, |
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195 | void *arg |
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196 | ) |
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197 | { |
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198 | rtems_libio_ioctl_args_t *args = arg; |
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199 | |
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200 | switch( args->command ) { |
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201 | case FBIOGET_FSCREENINFO: |
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202 | args->ioctl_return = get_fix_screen_info( ( struct fb_fix_screeninfo * ) args->buffer ); |
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203 | break; |
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204 | case FBIOGET_VSCREENINFO: |
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205 | args->ioctl_return = get_var_screen_info( ( struct fb_var_screeninfo * ) args->buffer ); |
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206 | break; |
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207 | case FBIOPUT_VSCREENINFO: |
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208 | /* not implemented yet */ |
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209 | args->ioctl_return = -1; |
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210 | return RTEMS_UNSATISFIED; |
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211 | case FBIOGETCMAP: |
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212 | /* not implemented yet */ |
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213 | args->ioctl_return = -1; |
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214 | return RTEMS_UNSATISFIED; |
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215 | break; |
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216 | case FBIOPUTCMAP: |
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217 | /* not implemented yet */ |
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218 | args->ioctl_return = -1; |
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219 | return RTEMS_UNSATISFIED; |
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220 | break; |
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221 | case FBIOSWAPBUFFERS: |
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222 | vga_swap_buffers(); |
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223 | args->ioctl_return = 0; |
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224 | break; |
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225 | case FBIOSETBUFFERMODE: |
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226 | args->ioctl_return = 0; |
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227 | switch ( (unsigned int)args->buffer ) { |
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228 | case FB_SINGLE_BUFFERED: |
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229 | fb_fix.smem_start = (volatile char *)frontbuffer; |
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230 | break; |
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231 | case FB_TRIPLE_BUFFERED: |
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232 | fb_fix.smem_start = (volatile char *)backbuffer; |
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233 | break; |
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234 | default: |
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235 | printk("[framebuffer] : error no such buffer mode\n"); |
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236 | } |
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237 | break; |
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238 | default: |
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239 | args->ioctl_return = 0; |
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240 | break; |
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241 | } |
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242 | return RTEMS_SUCCESSFUL; |
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243 | } |
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244 | |
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