shared/milkymist_framebuffer/framebuffer.c

0001 /*  framebuffer.c
0002  *
0003  *  This file is the framebuffer driver for the Milkymist VGA IP-core
0004  *  This VGA Core is a part of Milkymist System-on-Chip
0005  *
0006  *  The license and distribution terms for this file may be
0007  *  found in the file LICENSE in this distribution or at
0008  *  http://www.rtems.org/license/LICENSE.
0009  *
0010  *  COPYRIGHT (c) Yann Sionneau <yann.sionneau@telecom-sudparis.eu> (GSoC 2010)
0011  *  Telecom SudParis
0012  *  Copyright (c) 2011 Sebastien Bourdeauducq
0013  */
0014
0015 #include <stdlib.h>
0016 #include <stdio.h>
0017 #include <string.h>
0018 #include <errno.h>
0019 #include <sys/types.h>
0020 #include <rtems.h>
0021 #include <bsp.h>
0022 #include "../include/system_conf.h"
0023 #include <rtems/libio.h>
0024 #include <rtems/fb.h>
0025 #include <rtems/framebuffer.h>
0026 #include <rtems/bspIo.h>
0027
0028 static unsigned short int framebufferA[1024*768]
0029   __attribute__((aligned(32)));
0030 static unsigned short int framebufferB[1024*768]
0031   __attribute__((aligned(32)));
0032 static unsigned short int framebufferC[1024*768]
0033   __attribute__((aligned(32)));
0034
0035 static unsigned short int *frontbuffer;
0036 static unsigned short int *backbuffer;
0037 static unsigned short int *lastbuffer;
0038
0039 static struct fb_var_screeninfo fb_var = {
0040   .xres                = 640,
0041   .yres                = 480,
0042   .bits_per_pixel      = 16
0043 };
0044
0045 static struct fb_fix_screeninfo fb_fix = {
0046   .smem_len            = 1024 * 768 * 2,
0047   .type                = FB_TYPE_VGA_PLANES,
0048   .visual              = FB_VISUAL_TRUECOLOR,
0049   .line_length         = 80
0050 };
0051
0052 static int get_fix_screen_info( struct fb_fix_screeninfo *info )
0053 {
0054   *info = fb_fix;
0055   return 0;
0056 }
0057
0058 static int get_var_screen_info( struct fb_var_screeninfo *info )
0059 {
0060   *info =  fb_var;
0061   return 0;
0062 }
0063
0064 static void init_buffers(void)
0065 {
0066   frontbuffer = framebufferA;
0067   backbuffer = framebufferB;
0068   lastbuffer = framebufferC;
0069 }
0070
0071 static void swap_buffers(void)
0072 {
0073   unsigned short int *p;
0074
0075   /* Make sure last buffer swap has been executed */
0076   while (MM_READ(MM_VGA_BASEADDRESS_ACT) != MM_READ(MM_VGA_BASEADDRESS));
0077
0078   p = frontbuffer;
0079   frontbuffer = backbuffer;
0080   backbuffer = lastbuffer;
0081   lastbuffer = p;
0082
0083   fb_fix.smem_start = (volatile char *)backbuffer;
0084   MM_WRITE(MM_VGA_BASEADDRESS, (unsigned int)frontbuffer);
0085 }
0086
0087 static void set_video_mode(int mode)
0088 {
0089   int hres, vres;
0090
0091   MM_WRITE(MM_VGA_RESET, VGA_RESET);
0092   hres = vres = 0;
0093   switch(mode) {
0094     case 0: // 640x480, pixel clock: 25MHz
0095       hres = 640;
0096       vres = 480;
0097       MM_WRITE(MM_VGA_HSYNC_START, 656);
0098       MM_WRITE(MM_VGA_HSYNC_END, 752);
0099       MM_WRITE(MM_VGA_HSCAN, 799);
0100       MM_WRITE(MM_VGA_VSYNC_START, 492);
0101       MM_WRITE(MM_VGA_VSYNC_END, 494);
0102       MM_WRITE(MM_VGA_VSCAN, 524);
0103       MM_WRITE(MM_VGA_CLKSEL, 0);
0104       break;
0105     case 1: // 800x600, pixel clock: 50MHz
0106       hres = 800;
0107       vres = 600;
0108       MM_WRITE(MM_VGA_HSYNC_START, 848);
0109       MM_WRITE(MM_VGA_HSYNC_END, 976);
0110       MM_WRITE(MM_VGA_HSCAN, 1040);
0111       MM_WRITE(MM_VGA_VSYNC_START, 636);
0112       MM_WRITE(MM_VGA_VSYNC_END, 642);
0113       MM_WRITE(MM_VGA_VSCAN, 665);
0114       MM_WRITE(MM_VGA_CLKSEL, 1);
0115       break;
0116     case 2: // 1024x768, pixel clock: 65MHz
0117       hres = 1024;
0118       vres = 768;
0119       MM_WRITE(MM_VGA_HSYNC_START, 1048);
0120       MM_WRITE(MM_VGA_HSYNC_END, 1184);
0121       MM_WRITE(MM_VGA_HSCAN, 1344);
0122       MM_WRITE(MM_VGA_VSYNC_START, 772);
0123       MM_WRITE(MM_VGA_VSYNC_END, 778);
0124       MM_WRITE(MM_VGA_VSCAN, 807);
0125       MM_WRITE(MM_VGA_CLKSEL, 2);
0126       break;
0127   }
0128   if((hres != 0) && (vres != 0)) {
0129     MM_WRITE(MM_VGA_HRES, hres);
0130     MM_WRITE(MM_VGA_VRES, vres);
0131     fb_var.xres = hres;
0132     fb_var.yres = vres;
0133     memset(framebufferA, 0, hres*vres*2);
0134     memset(framebufferB, 0, hres*vres*2);
0135     memset(framebufferC, 0, hres*vres*2);
0136     MM_WRITE(MM_VGA_BURST_COUNT, hres*vres/16);
0137     MM_WRITE(MM_VGA_RESET, 0);
0138   } /* otherwise, leave the VGA controller in reset */
0139 }
0140
0141 rtems_device_driver frame_buffer_initialize(
0142   rtems_device_major_number major,
0143   rtems_device_minor_number minor,
0144   void *arg
0145 )
0146 {
0147   rtems_status_code status;
0148
0149   init_buffers();
0150   fb_fix.smem_start = (volatile char *)frontbuffer;
0151   MM_WRITE(MM_VGA_BASEADDRESS, (unsigned int)frontbuffer);
0152
0153   status = rtems_io_register_name(FRAMEBUFFER_DEVICE_0_NAME, major, 0);
0154   if (status != RTEMS_SUCCESSFUL) {
0155     printk("Error registering frame buffer device!\n");
0156     rtems_fatal_error_occurred( status );
0157   }
0158
0159   return RTEMS_SUCCESSFUL;
0160 }
0161
0162 rtems_device_driver frame_buffer_close(
0163   rtems_device_major_number major,
0164   rtems_device_minor_number minor,
0165   void *arg
0166 )
0167 {
0168   return RTEMS_SUCCESSFUL;
0169 }
0170
0171 rtems_device_driver frame_buffer_open(
0172   rtems_device_major_number major,
0173   rtems_device_minor_number minor,
0174   void *arg
0175 )
0176 {
0177   return RTEMS_SUCCESSFUL;
0178 }
0179
0180 rtems_device_driver frame_buffer_read(
0181   rtems_device_major_number major,
0182   rtems_device_minor_number minor,
0183   void *arg
0184 )
0185 {
0186   rtems_libio_rw_args_t *rw_args = (rtems_libio_rw_args_t *)arg;
0187   rw_args->bytes_moved = ((rw_args->offset + rw_args->count) > fb_fix.smem_len)
0188     ? (fb_fix.smem_len - rw_args->offset) : rw_args->count;
0189   memcpy(rw_args->buffer, (const void *)(fb_fix.smem_start + rw_args->offset),
0190     rw_args->bytes_moved);
0191   return RTEMS_SUCCESSFUL;
0192 }
0193
0194 rtems_device_driver frame_buffer_write(
0195   rtems_device_major_number major,
0196   rtems_device_minor_number minor,
0197   void *arg
0198 )
0199 {
0200   rtems_libio_rw_args_t *rw_args = (rtems_libio_rw_args_t *)arg;
0201   rw_args->bytes_moved = ((rw_args->offset + rw_args->count) > fb_fix.smem_len)
0202      ? (fb_fix.smem_len - rw_args->offset) : rw_args->count;
0203   memcpy((void *)(fb_fix.smem_start + rw_args->offset), rw_args->buffer,
0204     rw_args->bytes_moved);
0205   return RTEMS_SUCCESSFUL;
0206 }
0207
0208 rtems_device_driver frame_buffer_control(
0209   rtems_device_major_number major,
0210   rtems_device_minor_number minor,
0211   void *arg
0212 )
0213 {
0214   rtems_libio_ioctl_args_t *args = arg;
0215
0216   switch (args->command) {
0217     case FBIOGET_FSCREENINFO:
0218       args->ioctl_return =
0219         get_fix_screen_info((struct fb_fix_screeninfo *)args->buffer);
0220       return RTEMS_SUCCESSFUL;
0221     case FBIOGET_VSCREENINFO:
0222       args->ioctl_return =
0223         get_var_screen_info((struct fb_var_screeninfo *)args->buffer);
0224       return RTEMS_SUCCESSFUL;
0225     case FBIOSWAPBUFFERS:
0226       swap_buffers();
0227       args->ioctl_return = 0;
0228       return RTEMS_SUCCESSFUL;
0229     case FBIOSETBUFFERMODE:
0230       args->ioctl_return = 0;
0231       switch ((unsigned int)args->buffer) {
0232         case FB_SINGLE_BUFFERED:
0233           init_buffers();
0234           fb_fix.smem_start = (volatile char *)frontbuffer;
0235           MM_WRITE(MM_VGA_BASEADDRESS, (unsigned int)frontbuffer);
0236           return RTEMS_SUCCESSFUL;
0237         case FB_TRIPLE_BUFFERED:
0238           fb_fix.smem_start = (volatile char *)backbuffer;
0239           return RTEMS_SUCCESSFUL;
0240         default:
0241           return RTEMS_UNSATISFIED;
0242       }
0243     case FBIOSETVIDEOMODE:
0244       set_video_mode((int)args->buffer);
0245       return RTEMS_SUCCESSFUL;
0246     default:
0247       args->ioctl_return = -1;
0248       return RTEMS_UNSATISFIED;
0249   }
0250 }
0251