Documentation / auxdisplay / cfag12864b-example.c

Based on kernel version 4.8. Page generated on 2016-10-06 23:10 EST.

	/*
	 *    Filename: cfag12864b-example.c
	 *     Version: 0.1.0
	 * Description: cfag12864b LCD userspace example program
	 *     License: GPLv2
	 *
	 *      Author: Copyright (C) Miguel Ojeda Sandonis
	 *        Date: 2006-10-31
	 *
	 *  This program is free software; you can redistribute it and/or modify
	 *  it under the terms of the GNU General Public License version 2 as
	 *  published by the Free Software Foundation.
	 *
	 *  This program is distributed in the hope that it will be useful,
	 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
	 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	 *  GNU General Public License for more details.
	 *
	 *  You should have received a copy of the GNU General Public License
	 *  along with this program; if not, write to the Free Software
	 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
	 *
	 */
	
	/*
	 * ------------------------
	 * start of cfag12864b code
	 * ------------------------
	 */
	
	#include <string.h>
	#include <fcntl.h>
	#include <unistd.h>
	#include <sys/types.h>
	#include <sys/stat.h>
	#include <sys/mman.h>
	
	#define CFAG12864B_WIDTH		(128)
	#define CFAG12864B_HEIGHT		(64)
	#define CFAG12864B_SIZE			(128 * 64 / 8)
	#define CFAG12864B_BPB			(8)
	#define CFAG12864B_ADDRESS(x, y)	((y) * CFAG12864B_WIDTH / \
						CFAG12864B_BPB + (x) / CFAG12864B_BPB)
	#define CFAG12864B_BIT(n)		(((unsigned char) 1) << (n))
	
	#undef CFAG12864B_DOCHECK
	#ifdef CFAG12864B_DOCHECK
		#define CFAG12864B_CHECK(x, y)		((x) < CFAG12864B_WIDTH && \
							(y) < CFAG12864B_HEIGHT)
	#else
		#define CFAG12864B_CHECK(x, y)		(1)
	#endif
	
	int cfag12864b_fd;
	unsigned char * cfag12864b_mem;
	unsigned char cfag12864b_buffer[CFAG12864B_SIZE];
	
	/*
	 * init a cfag12864b framebuffer device
	 *
	 * No error:       return = 0
	 * Unable to open: return = -1
	 * Unable to mmap: return = -2
	 */
	static int cfag12864b_init(char *path)
	{
		cfag12864b_fd = open(path, O_RDWR);
		if (cfag12864b_fd == -1)
			return -1;
	
		cfag12864b_mem = mmap(0, CFAG12864B_SIZE, PROT_READ | PROT_WRITE,
			MAP_SHARED, cfag12864b_fd, 0);
		if (cfag12864b_mem == MAP_FAILED) {
			close(cfag12864b_fd);
			return -2;
		}
	
		return 0;
	}
	
	/*
	 * exit a cfag12864b framebuffer device
	 */
	static void cfag12864b_exit(void)
	{
		munmap(cfag12864b_mem, CFAG12864B_SIZE);
		close(cfag12864b_fd);
	}
	
	/*
	 * set (x, y) pixel
	 */
	static void cfag12864b_set(unsigned char x, unsigned char y)
	{
		if (CFAG12864B_CHECK(x, y))
			cfag12864b_buffer[CFAG12864B_ADDRESS(x, y)] |=
				CFAG12864B_BIT(x % CFAG12864B_BPB);
	}
	
	/*
	 * unset (x, y) pixel
	 */
	static void cfag12864b_unset(unsigned char x, unsigned char y)
	{
		if (CFAG12864B_CHECK(x, y))
			cfag12864b_buffer[CFAG12864B_ADDRESS(x, y)] &=
				~CFAG12864B_BIT(x % CFAG12864B_BPB);
	}
	
	/*
	 * is set (x, y) pixel?
	 *
	 * Pixel off: return = 0
	 * Pixel on:  return = 1
	 */
	static unsigned char cfag12864b_isset(unsigned char x, unsigned char y)
	{
		if (CFAG12864B_CHECK(x, y))
			if (cfag12864b_buffer[CFAG12864B_ADDRESS(x, y)] &
				CFAG12864B_BIT(x % CFAG12864B_BPB))
				return 1;
	
		return 0;
	}
	
	/*
	 * not (x, y) pixel
	 */
	static void cfag12864b_not(unsigned char x, unsigned char y)
	{
		if (cfag12864b_isset(x, y))
			cfag12864b_unset(x, y);
		else
			cfag12864b_set(x, y);
	}
	
	/*
	 * fill (set all pixels)
	 */
	static void cfag12864b_fill(void)
	{
		unsigned short i;
	
		for (i = 0; i < CFAG12864B_SIZE; i++)
			cfag12864b_buffer[i] = 0xFF;
	}
	
	/*
	 * clear (unset all pixels)
	 */
	static void cfag12864b_clear(void)
	{
		unsigned short i;
	
		for (i = 0; i < CFAG12864B_SIZE; i++)
			cfag12864b_buffer[i] = 0;
	}
	
	/*
	 * format a [128*64] matrix
	 *
	 * Pixel off: src[i] = 0
	 * Pixel on:  src[i] > 0
	 */
	static void cfag12864b_format(unsigned char * matrix)
	{
		unsigned char i, j, n;
	
		for (i = 0; i < CFAG12864B_HEIGHT; i++)
		for (j = 0; j < CFAG12864B_WIDTH / CFAG12864B_BPB; j++) {
			cfag12864b_buffer[i * CFAG12864B_WIDTH / CFAG12864B_BPB +
				j] = 0;
			for (n = 0; n < CFAG12864B_BPB; n++)
				if (matrix[i * CFAG12864B_WIDTH +
					j * CFAG12864B_BPB + n])
					cfag12864b_buffer[i * CFAG12864B_WIDTH /
						CFAG12864B_BPB + j] |=
						CFAG12864B_BIT(n);
		}
	}
	
	/*
	 * blit buffer to lcd
	 */
	static void cfag12864b_blit(void)
	{
		memcpy(cfag12864b_mem, cfag12864b_buffer, CFAG12864B_SIZE);
	}
	
	/*
	 * ----------------------
	 * end of cfag12864b code
	 * ----------------------
	 */
	
	#include <stdio.h>
	
	#define EXAMPLES	6
	
	static void example(unsigned char n)
	{
		unsigned short i, j;
		unsigned char matrix[CFAG12864B_WIDTH * CFAG12864B_HEIGHT];
	
		if (n > EXAMPLES)
			return;
	
		printf("Example %i/%i - ", n, EXAMPLES);
	
		switch (n) {
		case 1:
			printf("Draw points setting bits");
			cfag12864b_clear();
			for (i = 0; i < CFAG12864B_WIDTH; i += 2)
				for (j = 0; j < CFAG12864B_HEIGHT; j += 2)
					cfag12864b_set(i, j);
			break;
	
		case 2:
			printf("Clear the LCD");
			cfag12864b_clear();
			break;
	
		case 3:
			printf("Draw rows formatting a [128*64] matrix");
			memset(matrix, 0, CFAG12864B_WIDTH * CFAG12864B_HEIGHT);
			for (i = 0; i < CFAG12864B_WIDTH; i++)
				for (j = 0; j < CFAG12864B_HEIGHT; j += 2)
					matrix[j * CFAG12864B_WIDTH + i] = 1;
			cfag12864b_format(matrix);
			break;
	
		case 4:
			printf("Fill the lcd");
			cfag12864b_fill();
			break;
	
		case 5:
			printf("Draw columns unsetting bits");
			for (i = 0; i < CFAG12864B_WIDTH; i += 2)
				for (j = 0; j < CFAG12864B_HEIGHT; j++)
					cfag12864b_unset(i, j);
			break;
	
		case 6:
			printf("Do negative not-ing all bits");
			for (i = 0; i < CFAG12864B_WIDTH; i++)
				for (j = 0; j < CFAG12864B_HEIGHT; j ++)
					cfag12864b_not(i, j);
			break;
		}
	
		puts(" - [Press Enter]");
	}
	
	int main(int argc, char *argv[])
	{
		unsigned char n;
	
		if (argc != 2) {
			printf(
				"Sintax:  %s fbdev\n"
				"Usually: /dev/fb0, /dev/fb1...\n", argv[0]);
			return -1;
		}
	
		if (cfag12864b_init(argv[1])) {
			printf("Can't init %s fbdev\n", argv[1]);
			return -2;
		}
	
		for (n = 1; n <= EXAMPLES; n++) {
			example(n);
			cfag12864b_blit();
			while (getchar() != '\n');
		}
	
		cfag12864b_exit();
	
		return 0;
	}

• [ auxdisplay ]
• cfag12864b
• cfag12864b-example.c
• ks0108
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