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8#include <linux/module.h>
9#include <linux/kernel.h>
10#include <linux/init.h>
11#include <linux/gpio/consumer.h>
12#include <linux/delay.h>
13#include <linux/slab.h>
14
15#include "fbtft.h"
16
17
18
19
20#define WHITE 0xff
21#define BLACK 0
22
23#define DRVNAME "fb_agm1264k-fl"
24#define WIDTH 64
25#define HEIGHT 64
26#define TOTALWIDTH (WIDTH * 2)
27#define FPS 20
28
29#define EPIN gpio.wr
30#define RS gpio.dc
31#define RW gpio.aux[2]
32#define CS0 gpio.aux[0]
33#define CS1 gpio.aux[1]
34
35
36#define DIFFUSING_MATRIX_WIDTH 2
37#define DIFFUSING_MATRIX_HEIGHT 2
38
39static const signed char
40diffusing_matrix[DIFFUSING_MATRIX_WIDTH][DIFFUSING_MATRIX_HEIGHT] = {
41 {-1, 3},
42 {3, 2},
43};
44
45static const unsigned char gamma_correction_table[] = {
460, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1,
471, 1, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 6,
486, 6, 6, 7, 7, 7, 8, 8, 8, 9, 9, 9, 10, 10, 11, 11, 11, 12, 12, 13,
4913, 13, 14, 14, 15, 15, 16, 16, 17, 17, 18, 18, 19, 19, 20, 20, 21,
5022, 22, 23, 23, 24, 25, 25, 26, 26, 27, 28, 28, 29, 30, 30, 31, 32,
5133, 33, 34, 35, 35, 36, 37, 38, 39, 39, 40, 41, 42, 43, 43, 44, 45,
5246, 47, 48, 49, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61,
5362, 63, 64, 65, 66, 67, 68, 69, 70, 71, 73, 74, 75, 76, 77, 78, 79, 81,
5482, 83, 84, 85, 87, 88, 89, 90, 91, 93, 94, 95, 97, 98, 99, 100, 102,
55103, 105, 106, 107, 109, 110, 111, 113, 114, 116, 117, 119, 120, 121,
56123, 124, 126, 127, 129, 130, 132, 133, 135, 137, 138, 140, 141, 143,
57145, 146, 148, 149, 151, 153, 154, 156, 158, 159, 161, 163, 165, 166,
58168, 170, 172, 173, 175, 177, 179, 181, 182, 184, 186, 188, 190, 192,
59194, 196, 197, 199, 201, 203, 205, 207, 209, 211, 213, 215, 217, 219,
60221, 223, 225, 227, 229, 231, 234, 236, 238, 240, 242, 244, 246, 248,
61251, 253, 255
62};
63
64static int init_display(struct fbtft_par *par)
65{
66 u8 i;
67
68 par->fbtftops.reset(par);
69
70 for (i = 0; i < 2; ++i) {
71 write_reg(par, i, 0x3f);
72 write_reg(par, i, 0x40);
73 write_reg(par, i, 0xb0);
74 write_reg(par, i, 0xc0);
75 }
76
77 return 0;
78}
79
80
81static int verify_gpios(struct fbtft_par *par)
82{
83 int i;
84
85 dev_dbg(par->info->device,
86 "%s()\n", __func__);
87
88 if (!par->EPIN) {
89 dev_err(par->info->device,
90 "Missing info about 'wr' (aka E) gpio. Aborting.\n");
91 return -EINVAL;
92 }
93 for (i = 0; i < 8; ++i) {
94 if (!par->gpio.db[i]) {
95 dev_err(par->info->device,
96 "Missing info about 'db[%i]' gpio. Aborting.\n",
97 i);
98 return -EINVAL;
99 }
100 }
101 if (!par->CS0) {
102 dev_err(par->info->device,
103 "Missing info about 'cs0' gpio. Aborting.\n");
104 return -EINVAL;
105 }
106 if (!par->CS1) {
107 dev_err(par->info->device,
108 "Missing info about 'cs1' gpio. Aborting.\n");
109 return -EINVAL;
110 }
111 if (!par->RW) {
112 dev_err(par->info->device,
113 "Missing info about 'rw' gpio. Aborting.\n");
114 return -EINVAL;
115 }
116
117 return 0;
118}
119
120static unsigned long
121request_gpios_match(struct fbtft_par *par, const struct fbtft_gpio *gpio)
122{
123 dev_dbg(par->info->device,
124 "%s('%s')\n", __func__, gpio->name);
125
126 if (strcasecmp(gpio->name, "wr") == 0) {
127
128 par->EPIN = gpio->gpio;
129 return GPIOD_OUT_LOW;
130 } else if (strcasecmp(gpio->name, "cs0") == 0) {
131
132 par->CS0 = gpio->gpio;
133 return GPIOD_OUT_HIGH;
134 } else if (strcasecmp(gpio->name, "cs1") == 0) {
135
136 par->CS1 = gpio->gpio;
137 return GPIOD_OUT_HIGH;
138 }
139
140
141
142 else if (strcasecmp(gpio->name, "rw") == 0) {
143 par->RW = gpio->gpio;
144 return GPIOD_OUT_LOW;
145 }
146
147 return FBTFT_GPIO_NO_MATCH;
148}
149
150
151
152
153
154static void write_reg8_bus8(struct fbtft_par *par, int len, ...)
155{
156 va_list args;
157 int i, ret;
158 u8 *buf = par->buf;
159
160 if (unlikely(par->debug & DEBUG_WRITE_REGISTER)) {
161 va_start(args, len);
162 for (i = 0; i < len; i++)
163 buf[i] = (u8)va_arg(args, unsigned int);
164
165 va_end(args);
166 fbtft_par_dbg_hex(DEBUG_WRITE_REGISTER, par, par->info->device,
167 u8, buf, len, "%s: ", __func__);
168}
169
170 va_start(args, len);
171
172 *buf = (u8)va_arg(args, unsigned int);
173
174 if (*buf > 1) {
175 va_end(args);
176 dev_err(par->info->device,
177 "Incorrect chip select request (%d)\n", *buf);
178 return;
179 }
180
181
182 if (*buf) {
183
184 gpiod_set_value(par->CS0, 0);
185 gpiod_set_value(par->CS1, 1);
186 } else {
187
188 gpiod_set_value(par->CS0, 1);
189 gpiod_set_value(par->CS1, 0);
190 }
191
192 gpiod_set_value(par->RS, 0);
193 len--;
194
195 if (len) {
196 i = len;
197 while (i--)
198 *buf++ = (u8)va_arg(args, unsigned int);
199 ret = par->fbtftops.write(par, par->buf, len * (sizeof(u8)));
200 if (ret < 0) {
201 va_end(args);
202 dev_err(par->info->device,
203 "write() failed and returned %d\n", ret);
204 return;
205 }
206 }
207
208 va_end(args);
209}
210
211static struct
212{
213 int xs, ys_page, xe, ye_page;
214} addr_win;
215
216
217static void set_addr_win(struct fbtft_par *par, int xs, int ys, int xe, int ye)
218{
219 addr_win.xs = xs;
220 addr_win.ys_page = ys / 8;
221 addr_win.xe = xe;
222 addr_win.ye_page = ye / 8;
223}
224
225static void
226construct_line_bitmap(struct fbtft_par *par, u8 *dest, signed short *src,
227 int xs, int xe, int y)
228{
229 int x, i;
230
231 for (x = xs; x < xe; ++x) {
232 u8 res = 0;
233
234 for (i = 0; i < 8; i++)
235 if (src[(y * 8 + i) * par->info->var.xres + x])
236 res |= 1 << i;
237#ifdef NEGATIVE
238 *dest++ = res;
239#else
240 *dest++ = ~res;
241#endif
242 }
243}
244
245static void iterate_diffusion_matrix(u32 xres, u32 yres, int x,
246 int y, signed short *convert_buf,
247 signed short pixel, signed short error)
248{
249 u16 i, j;
250
251
252 for (i = 0; i < DIFFUSING_MATRIX_WIDTH; ++i)
253
254 for (j = 0; j < DIFFUSING_MATRIX_HEIGHT; ++j) {
255 signed short *write_pos;
256 signed char coeff;
257
258
259 if (x + i < 0 || x + i >= xres || y + j >= yres)
260 continue;
261 write_pos = &convert_buf[(y + j) * xres + x + i];
262 coeff = diffusing_matrix[i][j];
263 if (-1 == coeff) {
264
265 *write_pos = pixel;
266 } else {
267 signed short p = *write_pos + error * coeff;
268
269 if (p > WHITE)
270 p = WHITE;
271 if (p < BLACK)
272 p = BLACK;
273 *write_pos = p;
274 }
275 }
276}
277
278static int write_vmem(struct fbtft_par *par, size_t offset, size_t len)
279{
280 u16 *vmem16 = (u16 *)par->info->screen_buffer;
281 u8 *buf = par->txbuf.buf;
282 int x, y;
283 int ret = 0;
284
285
286 signed short *convert_buf = kmalloc_array(par->info->var.xres *
287 par->info->var.yres, sizeof(signed short), GFP_NOIO);
288
289 if (!convert_buf)
290 return -ENOMEM;
291
292
293 for (x = 0; x < par->info->var.xres; ++x)
294 for (y = 0; y < par->info->var.yres; ++y) {
295 u16 pixel = vmem16[y * par->info->var.xres + x];
296 u16 b = pixel & 0x1f;
297 u16 g = (pixel & (0x3f << 5)) >> 5;
298 u16 r = (pixel & (0x1f << (5 + 6))) >> (5 + 6);
299
300 pixel = (299 * r + 587 * g + 114 * b) / 200;
301 if (pixel > 255)
302 pixel = 255;
303
304
305 convert_buf[y * par->info->var.xres + x] =
306 (signed short)gamma_correction_table[pixel];
307 }
308
309
310 for (x = 0; x < par->info->var.xres; ++x)
311 for (y = 0; y < par->info->var.yres; ++y) {
312 signed short pixel =
313 convert_buf[y * par->info->var.xres + x];
314 signed short error_b = pixel - BLACK;
315 signed short error_w = pixel - WHITE;
316 signed short error;
317
318
319 if (abs(error_b) >= abs(error_w)) {
320
321 error = error_w;
322 pixel = 0xff;
323 } else {
324
325 error = error_b;
326 pixel = 0;
327 }
328
329 error /= 8;
330
331 iterate_diffusion_matrix(par->info->var.xres,
332 par->info->var.yres,
333 x, y, convert_buf,
334 pixel, error);
335 }
336
337
338 for (y = addr_win.ys_page; y <= addr_win.ye_page; ++y) {
339
340 if (addr_win.xs < par->info->var.xres / 2) {
341 construct_line_bitmap(par, buf, convert_buf,
342 addr_win.xs,
343 par->info->var.xres / 2, y);
344
345 len = par->info->var.xres / 2 - addr_win.xs;
346
347
348
349
350 write_reg(par, 0x00, BIT(6) | (u8)addr_win.xs);
351 write_reg(par, 0x00, (0x17 << 3) | (u8)y);
352
353
354 gpiod_set_value(par->RS, 1);
355 ret = par->fbtftops.write(par, buf, len);
356 if (ret < 0)
357 dev_err(par->info->device,
358 "write failed and returned: %d\n",
359 ret);
360 }
361
362 if (addr_win.xe >= par->info->var.xres / 2) {
363 construct_line_bitmap(par, buf,
364 convert_buf,
365 par->info->var.xres / 2,
366 addr_win.xe + 1, y);
367
368 len = addr_win.xe + 1 - par->info->var.xres / 2;
369
370
371
372
373 write_reg(par, 0x01, BIT(6));
374 write_reg(par, 0x01, (0x17 << 3) | (u8)y);
375
376
377 gpiod_set_value(par->RS, 1);
378 par->fbtftops.write(par, buf, len);
379 if (ret < 0)
380 dev_err(par->info->device,
381 "write failed and returned: %d\n",
382 ret);
383 }
384 }
385 kfree(convert_buf);
386
387 gpiod_set_value(par->CS0, 0);
388 gpiod_set_value(par->CS1, 0);
389
390 return ret;
391}
392
393static int write(struct fbtft_par *par, void *buf, size_t len)
394{
395 fbtft_par_dbg_hex(DEBUG_WRITE, par, par->info->device, u8, buf, len,
396 "%s(len=%zu): ", __func__, len);
397
398 gpiod_set_value(par->RW, 0);
399
400 while (len--) {
401 u8 i, data;
402
403 data = *(u8 *)buf++;
404
405
406 for (i = 0; i < 8; ++i)
407 gpiod_set_value(par->gpio.db[i], data & (1 << i));
408
409 gpiod_set_value(par->EPIN, 0);
410 udelay(5);
411
412 gpiod_set_value(par->EPIN, 1);
413 udelay(1);
414 }
415
416 return 0;
417}
418
419static struct fbtft_display display = {
420 .regwidth = 8,
421 .width = TOTALWIDTH,
422 .height = HEIGHT,
423 .fps = FPS,
424 .fbtftops = {
425 .init_display = init_display,
426 .set_addr_win = set_addr_win,
427 .verify_gpios = verify_gpios,
428 .request_gpios_match = request_gpios_match,
429 .write = write,
430 .write_register = write_reg8_bus8,
431 .write_vmem = write_vmem,
432 },
433};
434
435FBTFT_REGISTER_DRIVER(DRVNAME, "displaytronic,fb_agm1264k-fl", &display);
436
437MODULE_ALIAS("platform:" DRVNAME);
438
439MODULE_DESCRIPTION("Two KS0108 LCD controllers in AGM1264K-FL display");
440MODULE_AUTHOR("ololoshka2871");
441MODULE_LICENSE("GPL");
442
