diff options
Diffstat (limited to 'c/src/lib/libbsp/lm32/shared/milkymist_framebuffer/framebuffer.c')
| -rw-r--r-- | c/src/lib/libbsp/lm32/shared/milkymist_framebuffer/framebuffer.c | 244 |
1 files changed, 244 insertions, 0 deletions
diff --git a/c/src/lib/libbsp/lm32/shared/milkymist_framebuffer/framebuffer.c b/c/src/lib/libbsp/lm32/shared/milkymist_framebuffer/framebuffer.c new file mode 100644 index 0000000000..2fbb9c0eca --- /dev/null +++ b/c/src/lib/libbsp/lm32/shared/milkymist_framebuffer/framebuffer.c @@ -0,0 +1,244 @@ +/* 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.com/license/LICENSE. + * + * $Id$ + * + * COPYRIGHT (c) Yann Sionneau <yann.sionneau@telecom-sudparis.eu> (GSoC 2010) + * Telecom SudParis + */ + +#include <stdlib.h> +#include <stdio.h> +#include <errno.h> +#include <sys/types.h> +#include <pthread.h> +#include <rtems.h> +#include <bsp.h> +#include "../include/system_conf.h" +#include <rtems/libio.h> +#include <rtems/fb.h> + +#define FRAMEBUFFER_DEVICE_NAME "/dev/fb" + +pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER; + +static unsigned short int framebufferA[640*480] __attribute__((aligned(32))); +static unsigned short int framebufferB[640*480] __attribute__((aligned(32))); +static unsigned short int framebufferC[640*480] __attribute__((aligned(32))); + +static unsigned short int *frontbuffer = framebufferA; +static unsigned short int *backbuffer = framebufferB; +static unsigned short int *lastbuffer = framebufferC; + +static inline void fb_write(unsigned int reg, int value) +{ + *((int*)reg) = value; +} + +static inline int fb_read(unsigned int reg) +{ + return *((int*)(reg)); +} + +/* screen information for the VGA driver */ +static struct fb_var_screeninfo fb_var = +{ + .xres = 640, + .yres = 480, + .bits_per_pixel = 16 +}; + +static struct fb_fix_screeninfo fb_fix = +{ +// this is initialized at start-up + .smem_len = 640 * 480 * 2, /* buffer size */ +// 2 bytes per pixels + .type = FB_TYPE_VGA_PLANES, /* type of display */ + .visual = FB_VISUAL_TRUECOLOR, /* color scheme used */ + .line_length = 80 /* chars per line */ +}; + + +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; +} + + +rtems_device_driver frame_buffer_initialize( +rtems_device_major_number major, +rtems_device_minor_number minor, +void *arg) +{ + rtems_status_code status; + + printk( "frame buffer driver initializing..\n" ); + + fb_fix.smem_start = (volatile char *)frontbuffer; + + fb_write(MM_VGA_BASEADDRESS, (unsigned int)frontbuffer); + fb_write(MM_VGA_RESET, (unsigned int)0); + + /* + * Register the device + */ + status = rtems_io_register_name(FRAMEBUFFER_DEVICE_NAME, major, 0); + if (status != RTEMS_SUCCESSFUL) + { + printk("Error registering frame buffer device!\n"); + rtems_fatal_error_occurred( status ); + } + + printk("VGA: initialized at resolution %dx%d\n", fb_var.xres, fb_var.yres); + printk("VGA: framebuffers at 0x%08x 0x%08x 0x%08x\n", + (unsigned int)frontbuffer, (unsigned int)backbuffer, + (unsigned int)lastbuffer); + + /* + * graphics hardware initialization goes here for non-console + * devices + */ + return RTEMS_SUCCESSFUL; +} + +rtems_device_driver frame_buffer_close( + rtems_device_major_number major, + rtems_device_minor_number minor, + void *arg +) +{ + if (pthread_mutex_unlock(&mutex) == 0){ + /* restore previous state. for VGA this means return to text mode. + * leave out if graphics hardware has been initialized in + * frame_buffer_initialize() */ + fb_write(MM_VGA_RESET, MM_VGA_RESET_MODE); + return RTEMS_SUCCESSFUL; + } + return RTEMS_UNSATISFIED; +} + +rtems_device_driver frame_buffer_open( + rtems_device_major_number major, + rtems_device_minor_number minor, + void *arg +) +{ + if (pthread_mutex_trylock(&mutex) == 0){ + fb_write(MM_VGA_RESET, (unsigned int)0); + return RTEMS_SUCCESSFUL; + } + return RTEMS_UNSATISFIED; +} + +static void vga_swap_buffers(void) +{ + unsigned short int *p; + + /* + * Make sure last buffer swap has been executed. + * Beware, DMA address registers of vgafb are incomplete + * (only LSBs are present) so don't compare them directly + * with CPU pointers. + */ + while( fb_read(MM_VGA_BASEADDRESS_ACT) != fb_read(MM_VGA_BASEADDRESS) ); + + p = frontbuffer; + frontbuffer = backbuffer; + backbuffer = lastbuffer; + lastbuffer = p; + + fb_fix.smem_start = (volatile char *)backbuffer; + + fb_write(MM_VGA_BASEADDRESS, (unsigned int)frontbuffer); +} + +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 ); + break; + case FBIOGET_VSCREENINFO: + args->ioctl_return = get_var_screen_info( ( struct fb_var_screeninfo * ) args->buffer ); + break; + case FBIOPUT_VSCREENINFO: + /* not implemented yet */ + args->ioctl_return = -1; + return RTEMS_UNSATISFIED; + case FBIOGETCMAP: + /* not implemented yet */ + args->ioctl_return = -1; + return RTEMS_UNSATISFIED; + break; + case FBIOPUTCMAP: + /* not implemented yet */ + args->ioctl_return = -1; + return RTEMS_UNSATISFIED; + break; + case FBIOSWAPBUFFERS: + vga_swap_buffers(); + args->ioctl_return = 0; + break; + case FBIOSETBUFFERMODE: + args->ioctl_return = 0; + switch ( (unsigned int)args->buffer ) { + case FB_SINGLE_BUFFERED: + fb_fix.smem_start = (volatile char *)frontbuffer; + break; + case FB_TRIPLE_BUFFERED: + fb_fix.smem_start = (volatile char *)backbuffer; + break; + default: + printk("[framebuffer] : error no such buffer mode\n"); + } + break; + default: + args->ioctl_return = 0; + break; + } + return RTEMS_SUCCESSFUL; +} + |