/* framebuffer.c
*
* This file is the framebuffer driver for the Milkymist VGA IP-core
* This VGA Core is a part of Milkymist System-on-Chip
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.org/license/LICENSE.
*
* COPYRIGHT (c) Yann Sionneau <yann.sionneau@telecom-sudparis.eu> (GSoC 2010)
* Telecom SudParis
* Copyright (c) 2011 Sebastien Bourdeauducq
*/
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <sys/types.h>
#include <rtems.h>
#include <bsp.h>
#include "../include/system_conf.h"
#include <rtems/libio.h>
#include <rtems/fb.h>
#include <rtems/framebuffer.h>
static unsigned short int framebufferA[1024*768]
__attribute__((aligned(32)));
static unsigned short int framebufferB[1024*768]
__attribute__((aligned(32)));
static unsigned short int framebufferC[1024*768]
__attribute__((aligned(32)));
static unsigned short int *frontbuffer;
static unsigned short int *backbuffer;
static unsigned short int *lastbuffer;
static struct fb_var_screeninfo fb_var = {
.xres = 640,
.yres = 480,
.bits_per_pixel = 16
};
static struct fb_fix_screeninfo fb_fix = {
.smem_len = 1024 * 768 * 2,
.type = FB_TYPE_VGA_PLANES,
.visual = FB_VISUAL_TRUECOLOR,
.line_length = 80
};
static int get_fix_screen_info( struct fb_fix_screeninfo *info )
{
*info = fb_fix;
return 0;
}
static int get_var_screen_info( struct fb_var_screeninfo *info )
{
*info = fb_var;
return 0;
}
static void init_buffers(void)
{
frontbuffer = framebufferA;
backbuffer = framebufferB;
lastbuffer = framebufferC;
}
static void swap_buffers(void)
{
unsigned short int *p;
/* Make sure last buffer swap has been executed */
while (MM_READ(MM_VGA_BASEADDRESS_ACT) != MM_READ(MM_VGA_BASEADDRESS));
p = frontbuffer;
frontbuffer = backbuffer;
backbuffer = lastbuffer;
lastbuffer = p;
fb_fix.smem_start = (volatile char *)backbuffer;
MM_WRITE(MM_VGA_BASEADDRESS, (unsigned int)frontbuffer);
}
static void set_video_mode(int mode)
{
int hres, vres;
MM_WRITE(MM_VGA_RESET, VGA_RESET);
hres = vres = 0;
switch(mode) {
case 0: // 640x480, pixel clock: 25MHz
hres = 640;
vres = 480;
MM_WRITE(MM_VGA_HSYNC_START, 656);
MM_WRITE(MM_VGA_HSYNC_END, 752);
MM_WRITE(MM_VGA_HSCAN, 799);
MM_WRITE(MM_VGA_VSYNC_START, 492);
MM_WRITE(MM_VGA_VSYNC_END, 494);
MM_WRITE(MM_VGA_VSCAN, 524);
MM_WRITE(MM_VGA_CLKSEL, 0);
break;
case 1: // 800x600, pixel clock: 50MHz
hres = 800;
vres = 600;
MM_WRITE(MM_VGA_HSYNC_START, 848);
MM_WRITE(MM_VGA_HSYNC_END, 976);
MM_WRITE(MM_VGA_HSCAN, 1040);
MM_WRITE(MM_VGA_VSYNC_START, 636);
MM_WRITE(MM_VGA_VSYNC_END, 642);
MM_WRITE(MM_VGA_VSCAN, 665);
MM_WRITE(MM_VGA_CLKSEL, 1);
break;
case 2: // 1024x768, pixel clock: 65MHz
hres = 1024;
vres = 768;
MM_WRITE(MM_VGA_HSYNC_START, 1048);
MM_WRITE(MM_VGA_HSYNC_END, 1184);
MM_WRITE(MM_VGA_HSCAN, 1344);
MM_WRITE(MM_VGA_VSYNC_START, 772);
MM_WRITE(MM_VGA_VSYNC_END, 778);
MM_WRITE(MM_VGA_VSCAN, 807);
MM_WRITE(MM_VGA_CLKSEL, 2);
break;
}
if((hres != 0) && (vres != 0)) {
MM_WRITE(MM_VGA_HRES, hres);
MM_WRITE(MM_VGA_VRES, vres);
fb_var.xres = hres;
fb_var.yres = vres;
memset(framebufferA, 0, hres*vres*2);
memset(framebufferB, 0, hres*vres*2);
memset(framebufferC, 0, hres*vres*2);
MM_WRITE(MM_VGA_BURST_COUNT, hres*vres/16);
MM_WRITE(MM_VGA_RESET, 0);
} /* otherwise, leave the VGA controller in reset */
}
rtems_device_driver frame_buffer_initialize(
rtems_device_major_number major,
rtems_device_minor_number minor,
void *arg
)
{
rtems_status_code status;
init_buffers();
fb_fix.smem_start = (volatile char *)frontbuffer;
MM_WRITE(MM_VGA_BASEADDRESS, (unsigned int)frontbuffer);
status = rtems_io_register_name(FRAMEBUFFER_DEVICE_0_NAME, major, 0);
if (status != RTEMS_SUCCESSFUL) {
printk("Error registering frame buffer device!\n");
rtems_fatal_error_occurred( status );
}
return RTEMS_SUCCESSFUL;
}
rtems_device_driver frame_buffer_close(
rtems_device_major_number major,
rtems_device_minor_number minor,
void *arg
)
{
return RTEMS_SUCCESSFUL;
}
rtems_device_driver frame_buffer_open(
rtems_device_major_number major,
rtems_device_minor_number minor,
void *arg
)
{
return RTEMS_SUCCESSFUL;
}
rtems_device_driver frame_buffer_read(
rtems_device_major_number major,
rtems_device_minor_number minor,
void *arg
)
{
rtems_libio_rw_args_t *rw_args = (rtems_libio_rw_args_t *)arg;
rw_args->bytes_moved = ((rw_args->offset + rw_args->count) > fb_fix.smem_len)
? (fb_fix.smem_len - rw_args->offset) : rw_args->count;
memcpy(rw_args->buffer, (const void *)(fb_fix.smem_start + rw_args->offset),
rw_args->bytes_moved);
return RTEMS_SUCCESSFUL;
}
rtems_device_driver frame_buffer_write(
rtems_device_major_number major,
rtems_device_minor_number minor,
void *arg
)
{
rtems_libio_rw_args_t *rw_args = (rtems_libio_rw_args_t *)arg;
rw_args->bytes_moved = ((rw_args->offset + rw_args->count) > fb_fix.smem_len)
? (fb_fix.smem_len - rw_args->offset) : rw_args->count;
memcpy((void *)(fb_fix.smem_start + rw_args->offset), rw_args->buffer,
rw_args->bytes_moved);
return RTEMS_SUCCESSFUL;
}
rtems_device_driver frame_buffer_control(
rtems_device_major_number major,
rtems_device_minor_number minor,
void *arg
)
{
rtems_libio_ioctl_args_t *args = arg;
switch (args->command) {
case FBIOGET_FSCREENINFO:
args->ioctl_return =
get_fix_screen_info((struct fb_fix_screeninfo *)args->buffer);
return RTEMS_SUCCESSFUL;
case FBIOGET_VSCREENINFO:
args->ioctl_return =
get_var_screen_info((struct fb_var_screeninfo *)args->buffer);
return RTEMS_SUCCESSFUL;
case FBIOSWAPBUFFERS:
swap_buffers();
args->ioctl_return = 0;
return RTEMS_SUCCESSFUL;
case FBIOSETBUFFERMODE:
args->ioctl_return = 0;
switch ((unsigned int)args->buffer) {
case FB_SINGLE_BUFFERED:
init_buffers();
fb_fix.smem_start = (volatile char *)frontbuffer;
MM_WRITE(MM_VGA_BASEADDRESS, (unsigned int)frontbuffer);
return RTEMS_SUCCESSFUL;
case FB_TRIPLE_BUFFERED:
fb_fix.smem_start = (volatile char *)backbuffer;
return RTEMS_SUCCESSFUL;
default:
return RTEMS_UNSATISFIED;
}
case FBIOSETVIDEOMODE:
set_video_mode((int)args->buffer);
return RTEMS_SUCCESSFUL;
default:
args->ioctl_return = -1;
return RTEMS_UNSATISFIED;
}
}