1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 *    Filename: cfag12864b-example.c
  4 *     Version: 0.1.0
  5 * Description: cfag12864b LCD userspace example program
  6 *
  7 *      Author: Copyright (C) Miguel Ojeda <ojeda@kernel.org>
  8 *        Date: 2006-10-31
  9 */
 10
 11/*
 12 * ------------------------
 13 * start of cfag12864b code
 14 * ------------------------
 15 */
 16
 17#include <string.h>
 18#include <fcntl.h>
 19#include <unistd.h>
 20#include <sys/types.h>
 21#include <sys/stat.h>
 22#include <sys/mman.h>
 23
 24#define CFAG12864B_WIDTH		(128)
 25#define CFAG12864B_HEIGHT		(64)
 26#define CFAG12864B_SIZE			(128 * 64 / 8)
 27#define CFAG12864B_BPB			(8)
 28#define CFAG12864B_ADDRESS(x, y)	((y) * CFAG12864B_WIDTH / \
 29					CFAG12864B_BPB + (x) / CFAG12864B_BPB)
 30#define CFAG12864B_BIT(n)		(((unsigned char) 1) << (n))
 31
 32#undef CFAG12864B_DOCHECK
 33#ifdef CFAG12864B_DOCHECK
 34	#define CFAG12864B_CHECK(x, y)		((x) < CFAG12864B_WIDTH && \
 35						(y) < CFAG12864B_HEIGHT)
 36#else
 37	#define CFAG12864B_CHECK(x, y)		(1)
 38#endif
 39
 40int cfag12864b_fd;
 41unsigned char * cfag12864b_mem;
 42unsigned char cfag12864b_buffer[CFAG12864B_SIZE];
 43
 44/*
 45 * init a cfag12864b framebuffer device
 46 *
 47 * No error:       return = 0
 48 * Unable to open: return = -1
 49 * Unable to mmap: return = -2
 50 */
 51static int cfag12864b_init(char *path)
 52{
 53	cfag12864b_fd = open(path, O_RDWR);
 54	if (cfag12864b_fd == -1)
 55		return -1;
 56
 57	cfag12864b_mem = mmap(0, CFAG12864B_SIZE, PROT_READ | PROT_WRITE,
 58		MAP_SHARED, cfag12864b_fd, 0);
 59	if (cfag12864b_mem == MAP_FAILED) {
 60		close(cfag12864b_fd);
 61		return -2;
 62	}
 63
 64	return 0;
 65}
 66
 67/*
 68 * exit a cfag12864b framebuffer device
 69 */
 70static void cfag12864b_exit(void)
 71{
 72	munmap(cfag12864b_mem, CFAG12864B_SIZE);
 73	close(cfag12864b_fd);
 74}
 75
 76/*
 77 * set (x, y) pixel
 78 */
 79static void cfag12864b_set(unsigned char x, unsigned char y)
 80{
 81	if (CFAG12864B_CHECK(x, y))
 82		cfag12864b_buffer[CFAG12864B_ADDRESS(x, y)] |=
 83			CFAG12864B_BIT(x % CFAG12864B_BPB);
 84}
 85
 86/*
 87 * unset (x, y) pixel
 88 */
 89static void cfag12864b_unset(unsigned char x, unsigned char y)
 90{
 91	if (CFAG12864B_CHECK(x, y))
 92		cfag12864b_buffer[CFAG12864B_ADDRESS(x, y)] &=
 93			~CFAG12864B_BIT(x % CFAG12864B_BPB);
 94}
 95
 96/*
 97 * is set (x, y) pixel?
 98 *
 99 * Pixel off: return = 0
100 * Pixel on:  return = 1
101 */
102static unsigned char cfag12864b_isset(unsigned char x, unsigned char y)
103{
104	if (CFAG12864B_CHECK(x, y))
105		if (cfag12864b_buffer[CFAG12864B_ADDRESS(x, y)] &
106			CFAG12864B_BIT(x % CFAG12864B_BPB))
107			return 1;
108
109	return 0;
110}
111
112/*
113 * not (x, y) pixel
114 */
115static void cfag12864b_not(unsigned char x, unsigned char y)
116{
117	if (cfag12864b_isset(x, y))
118		cfag12864b_unset(x, y);
119	else
120		cfag12864b_set(x, y);
121}
122
123/*
124 * fill (set all pixels)
125 */
126static void cfag12864b_fill(void)
127{
128	unsigned short i;
129
130	for (i = 0; i < CFAG12864B_SIZE; i++)
131		cfag12864b_buffer[i] = 0xFF;
132}
133
134/*
135 * clear (unset all pixels)
136 */
137static void cfag12864b_clear(void)
138{
139	unsigned short i;
140
141	for (i = 0; i < CFAG12864B_SIZE; i++)
142		cfag12864b_buffer[i] = 0;
143}
144
145/*
146 * format a [128*64] matrix
147 *
148 * Pixel off: src[i] = 0
149 * Pixel on:  src[i] > 0
150 */
151static void cfag12864b_format(unsigned char * matrix)
152{
153	unsigned char i, j, n;
154
155	for (i = 0; i < CFAG12864B_HEIGHT; i++)
156	for (j = 0; j < CFAG12864B_WIDTH / CFAG12864B_BPB; j++) {
157		cfag12864b_buffer[i * CFAG12864B_WIDTH / CFAG12864B_BPB +
158			j] = 0;
159		for (n = 0; n < CFAG12864B_BPB; n++)
160			if (matrix[i * CFAG12864B_WIDTH +
161				j * CFAG12864B_BPB + n])
162				cfag12864b_buffer[i * CFAG12864B_WIDTH /
163					CFAG12864B_BPB + j] |=
164					CFAG12864B_BIT(n);
165	}
166}
167
168/*
169 * blit buffer to lcd
170 */
171static void cfag12864b_blit(void)
172{
173	memcpy(cfag12864b_mem, cfag12864b_buffer, CFAG12864B_SIZE);
174}
175
176/*
177 * ----------------------
178 * end of cfag12864b code
179 * ----------------------
180 */
181
182#include <stdio.h>
183
184#define EXAMPLES	6
185
186static void example(unsigned char n)
187{
188	unsigned short i, j;
189	unsigned char matrix[CFAG12864B_WIDTH * CFAG12864B_HEIGHT];
190
191	if (n > EXAMPLES)
192		return;
193
194	printf("Example %i/%i - ", n, EXAMPLES);
195
196	switch (n) {
197	case 1:
198		printf("Draw points setting bits");
199		cfag12864b_clear();
200		for (i = 0; i < CFAG12864B_WIDTH; i += 2)
201			for (j = 0; j < CFAG12864B_HEIGHT; j += 2)
202				cfag12864b_set(i, j);
203		break;
204
205	case 2:
206		printf("Clear the LCD");
207		cfag12864b_clear();
208		break;
209
210	case 3:
211		printf("Draw rows formatting a [128*64] matrix");
212		memset(matrix, 0, CFAG12864B_WIDTH * CFAG12864B_HEIGHT);
213		for (i = 0; i < CFAG12864B_WIDTH; i++)
214			for (j = 0; j < CFAG12864B_HEIGHT; j += 2)
215				matrix[j * CFAG12864B_WIDTH + i] = 1;
216		cfag12864b_format(matrix);
217		break;
218
219	case 4:
220		printf("Fill the lcd");
221		cfag12864b_fill();
222		break;
223
224	case 5:
225		printf("Draw columns unsetting bits");
226		for (i = 0; i < CFAG12864B_WIDTH; i += 2)
227			for (j = 0; j < CFAG12864B_HEIGHT; j++)
228				cfag12864b_unset(i, j);
229		break;
230
231	case 6:
232		printf("Do negative not-ing all bits");
233		for (i = 0; i < CFAG12864B_WIDTH; i++)
234			for (j = 0; j < CFAG12864B_HEIGHT; j ++)
235				cfag12864b_not(i, j);
236		break;
237	}
238
239	puts(" - [Press Enter]");
240}
241
242int main(int argc, char *argv[])
243{
244	unsigned char n;
245
246	if (argc != 2) {
247		printf(
248			"Syntax:  %s fbdev\n"
249			"Usually: /dev/fb0, /dev/fb1...\n", argv[0]);
250		return -1;
251	}
252
253	if (cfag12864b_init(argv[1])) {
254		printf("Can't init %s fbdev\n", argv[1]);
255		return -2;
256	}
257
258	for (n = 1; n <= EXAMPLES; n++) {
259		example(n);
260		cfag12864b_blit();
261		while (getchar() != '\n');
262	}
263
264	cfag12864b_exit();
265
266	return 0;
267}