summaryrefslogtreecommitdiffstats
path: root/drivers/video/ssd1307fb.c
blob: 44967c8fef2b5a344d9e6a78e1339e148f2fbd20 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
/*
 * Driver for the Solomon SSD1307 OLED controller
 *
 * Copyright 2012 Free Electrons
 *
 * Licensed under the GPLv2 or later.
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/i2c.h>
#include <linux/fb.h>
#include <linux/uaccess.h>
#include <linux/of_device.h>
#include <linux/of_gpio.h>
#include <linux/pwm.h>
#include <linux/delay.h>

#define SSD1307FB_DATA			0x40
#define SSD1307FB_COMMAND		0x80

#define SSD1307FB_SET_ADDRESS_MODE	0x20
#define SSD1307FB_SET_ADDRESS_MODE_HORIZONTAL	(0x00)
#define SSD1307FB_SET_ADDRESS_MODE_VERTICAL	(0x01)
#define SSD1307FB_SET_ADDRESS_MODE_PAGE		(0x02)
#define SSD1307FB_SET_COL_RANGE		0x21
#define SSD1307FB_SET_PAGE_RANGE	0x22
#define SSD1307FB_CONTRAST		0x81
#define	SSD1307FB_CHARGE_PUMP		0x8d
#define SSD1307FB_SEG_REMAP_ON		0xa1
#define SSD1307FB_DISPLAY_OFF		0xae
#define SSD1307FB_SET_MULTIPLEX_RATIO	0xa8
#define SSD1307FB_DISPLAY_ON		0xaf
#define SSD1307FB_START_PAGE_ADDRESS	0xb0
#define SSD1307FB_SET_DISPLAY_OFFSET	0xd3
#define	SSD1307FB_SET_CLOCK_FREQ	0xd5
#define	SSD1307FB_SET_PRECHARGE_PERIOD	0xd9
#define	SSD1307FB_SET_COM_PINS_CONFIG	0xda
#define	SSD1307FB_SET_VCOMH		0xdb

struct ssd1307fb_par;

struct ssd1307fb_ops {
	int (*init)(struct ssd1307fb_par *);
	int (*remove)(struct ssd1307fb_par *);
};

struct ssd1307fb_par {
	struct i2c_client *client;
	u32 height;
	struct fb_info *info;
	struct ssd1307fb_ops *ops;
	u32 page_offset;
	struct pwm_device *pwm;
	u32 pwm_period;
	int reset;
	u32 width;
};

struct ssd1307fb_array {
	u8	type;
	u8	data[0];
};

static struct fb_fix_screeninfo ssd1307fb_fix = {
	.id		= "Solomon SSD1307",
	.type		= FB_TYPE_PACKED_PIXELS,
	.visual		= FB_VISUAL_MONO10,
	.xpanstep	= 0,
	.ypanstep	= 0,
	.ywrapstep	= 0,
	.accel		= FB_ACCEL_NONE,
};

static struct fb_var_screeninfo ssd1307fb_var = {
	.bits_per_pixel	= 1,
};

static struct ssd1307fb_array *ssd1307fb_alloc_array(u32 len, u8 type)
{
	struct ssd1307fb_array *array;

	array = kzalloc(sizeof(struct ssd1307fb_array) + len, GFP_KERNEL);
	if (!array)
		return NULL;

	array->type = type;

	return array;
}

static int ssd1307fb_write_array(struct i2c_client *client,
				 struct ssd1307fb_array *array, u32 len)
{
	int ret;

	len += sizeof(struct ssd1307fb_array);

	ret = i2c_master_send(client, (u8 *)array, len);
	if (ret != len) {
		dev_err(&client->dev, "Couldn't send I2C command.\n");
		return ret;
	}

	return 0;
}

static inline int ssd1307fb_write_cmd(struct i2c_client *client, u8 cmd)
{
	struct ssd1307fb_array *array;
	int ret;

	array = ssd1307fb_alloc_array(1, SSD1307FB_COMMAND);
	if (!array)
		return -ENOMEM;

	array->data[0] = cmd;

	ret = ssd1307fb_write_array(client, array, 1);
	kfree(array);

	return ret;
}

static inline int ssd1307fb_write_data(struct i2c_client *client, u8 data)
{
	struct ssd1307fb_array *array;
	int ret;

	array = ssd1307fb_alloc_array(1, SSD1307FB_DATA);
	if (!array)
		return -ENOMEM;

	array->data[0] = data;

	ret = ssd1307fb_write_array(client, array, 1);
	kfree(array);

	return ret;
}

static void ssd1307fb_update_display(struct ssd1307fb_par *par)
{
	struct ssd1307fb_array *array;
	u8 *vmem = par->info->screen_base;
	int i, j, k;

	array = ssd1307fb_alloc_array(par->width * par->height / 8,
				      SSD1307FB_DATA);
	if (!array)
		return;

	/*
	 * The screen is divided in pages, each having a height of 8
	 * pixels, and the width of the screen. When sending a byte of
	 * data to the controller, it gives the 8 bits for the current
	 * column. I.e, the first byte are the 8 bits of the first
	 * column, then the 8 bits for the second column, etc.
	 *
	 *
	 * Representation of the screen, assuming it is 5 bits
	 * wide. Each letter-number combination is a bit that controls
	 * one pixel.
	 *
	 * A0 A1 A2 A3 A4
	 * B0 B1 B2 B3 B4
	 * C0 C1 C2 C3 C4
	 * D0 D1 D2 D3 D4
	 * E0 E1 E2 E3 E4
	 * F0 F1 F2 F3 F4
	 * G0 G1 G2 G3 G4
	 * H0 H1 H2 H3 H4
	 *
	 * If you want to update this screen, you need to send 5 bytes:
	 *  (1) A0 B0 C0 D0 E0 F0 G0 H0
	 *  (2) A1 B1 C1 D1 E1 F1 G1 H1
	 *  (3) A2 B2 C2 D2 E2 F2 G2 H2
	 *  (4) A3 B3 C3 D3 E3 F3 G3 H3
	 *  (5) A4 B4 C4 D4 E4 F4 G4 H4
	 */

	for (i = 0; i < (par->height / 8); i++) {
		for (j = 0; j < par->width; j++) {
			u32 array_idx = i * par->width + j;
			array->data[array_idx] = 0;
			for (k = 0; k < 8; k++) {
				u32 page_length = par->width * i;
				u32 index = page_length + (par->width * k + j) / 8;
				u8 byte = *(vmem + index);
				u8 bit = byte & (1 << (j % 8));
				bit = bit >> (j % 8);
				array->data[array_idx] |= bit << k;
			}
		}
	}

	ssd1307fb_write_array(par->client, array, par->width * par->height / 8);
	kfree(array);
}


static ssize_t ssd1307fb_write(struct fb_info *info, const char __user *buf,
		size_t count, loff_t *ppos)
{
	struct ssd1307fb_par *par = info->par;
	unsigned long total_size;
	unsigned long p = *ppos;
	u8 __iomem *dst;

	total_size = info->fix.smem_len;

	if (p > total_size)
		return -EINVAL;

	if (count + p > total_size)
		count = total_size - p;

	if (!count)
		return -EINVAL;

	dst = (void __force *) (info->screen_base + p);

	if (copy_from_user(dst, buf, count))
		return -EFAULT;

	ssd1307fb_update_display(par);

	*ppos += count;

	return count;
}

static void ssd1307fb_fillrect(struct fb_info *info, const struct fb_fillrect *rect)
{
	struct ssd1307fb_par *par = info->par;
	sys_fillrect(info, rect);
	ssd1307fb_update_display(par);
}

static void ssd1307fb_copyarea(struct fb_info *info, const struct fb_copyarea *area)
{
	struct ssd1307fb_par *par = info->par;
	sys_copyarea(info, area);
	ssd1307fb_update_display(par);
}

static void ssd1307fb_imageblit(struct fb_info *info, const struct fb_image *image)
{
	struct ssd1307fb_par *par = info->par;
	sys_imageblit(info, image);
	ssd1307fb_update_display(par);
}

static struct fb_ops ssd1307fb_ops = {
	.owner		= THIS_MODULE,
	.fb_read	= fb_sys_read,
	.fb_write	= ssd1307fb_write,
	.fb_fillrect	= ssd1307fb_fillrect,
	.fb_copyarea	= ssd1307fb_copyarea,
	.fb_imageblit	= ssd1307fb_imageblit,
};

static void ssd1307fb_deferred_io(struct fb_info *info,
				struct list_head *pagelist)
{
	ssd1307fb_update_display(info->par);
}

static struct fb_deferred_io ssd1307fb_defio = {
	.delay		= HZ,
	.deferred_io	= ssd1307fb_deferred_io,
};

static int ssd1307fb_ssd1307_init(struct ssd1307fb_par *par)
{
	int ret;

	par->pwm = pwm_get(&par->client->dev, NULL);
	if (IS_ERR(par->pwm)) {
		dev_err(&par->client->dev, "Could not get PWM from device tree!\n");
		return PTR_ERR(par->pwm);
	}

	par->pwm_period = pwm_get_period(par->pwm);
	/* Enable the PWM */
	pwm_config(par->pwm, par->pwm_period / 2, par->pwm_period);
	pwm_enable(par->pwm);

	dev_dbg(&par->client->dev, "Using PWM%d with a %dns period.\n",
		par->pwm->pwm, par->pwm_period);

	/* Map column 127 of the OLED to segment 0 */
	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SEG_REMAP_ON);
	if (ret < 0)
		return ret;

	/* Turn on the display */
	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_DISPLAY_ON);
	if (ret < 0)
		return ret;

	return 0;
}

static int ssd1307fb_ssd1307_remove(struct ssd1307fb_par *par)
{
	pwm_disable(par->pwm);
	pwm_put(par->pwm);
	return 0;
}

static struct ssd1307fb_ops ssd1307fb_ssd1307_ops = {
	.init	= ssd1307fb_ssd1307_init,
	.remove	= ssd1307fb_ssd1307_remove,
};

static int ssd1307fb_ssd1306_init(struct ssd1307fb_par *par)
{
	int ret;

	/* Set initial contrast */
	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_CONTRAST);
	ret = ret & ssd1307fb_write_cmd(par->client, 0x7f);
	if (ret < 0)
		return ret;

	/* Set COM direction */
	ret = ssd1307fb_write_cmd(par->client, 0xc8);
	if (ret < 0)
		return ret;

	/* Set segment re-map */
	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SEG_REMAP_ON);
	if (ret < 0)
		return ret;

	/* Set multiplex ratio value */
	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_MULTIPLEX_RATIO);
	ret = ret & ssd1307fb_write_cmd(par->client, par->height - 1);
	if (ret < 0)
		return ret;

	/* set display offset value */
	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_DISPLAY_OFFSET);
	ret = ssd1307fb_write_cmd(par->client, 0x20);
	if (ret < 0)
		return ret;

	/* Set clock frequency */
	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_CLOCK_FREQ);
	ret = ret & ssd1307fb_write_cmd(par->client, 0xf0);
	if (ret < 0)
		return ret;

	/* Set precharge period in number of ticks from the internal clock */
	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_PRECHARGE_PERIOD);
	ret = ret & ssd1307fb_write_cmd(par->client, 0x22);
	if (ret < 0)
		return ret;

	/* Set COM pins configuration */
	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_COM_PINS_CONFIG);
	ret = ret & ssd1307fb_write_cmd(par->client, 0x22);
	if (ret < 0)
		return ret;

	/* Set VCOMH */
	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_VCOMH);
	ret = ret & ssd1307fb_write_cmd(par->client, 0x49);
	if (ret < 0)
		return ret;

	/* Turn on the DC-DC Charge Pump */
	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_CHARGE_PUMP);
	ret = ret & ssd1307fb_write_cmd(par->client, 0x14);
	if (ret < 0)
		return ret;

	/* Switch to horizontal addressing mode */
	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_ADDRESS_MODE);
	ret = ret & ssd1307fb_write_cmd(par->client,
					SSD1307FB_SET_ADDRESS_MODE_HORIZONTAL);
	if (ret < 0)
		return ret;

	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_COL_RANGE);
	ret = ret & ssd1307fb_write_cmd(par->client, 0x0);
	ret = ret & ssd1307fb_write_cmd(par->client, par->width - 1);
	if (ret < 0)
		return ret;

	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_PAGE_RANGE);
	ret = ret & ssd1307fb_write_cmd(par->client, 0x0);
	ret = ret & ssd1307fb_write_cmd(par->client,
					par->page_offset + (par->height / 8) - 1);
	if (ret < 0)
		return ret;

	/* Turn on the display */
	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_DISPLAY_ON);
	if (ret < 0)
		return ret;

	return 0;
}

static struct ssd1307fb_ops ssd1307fb_ssd1306_ops = {
	.init	= ssd1307fb_ssd1306_init,
};

static const struct of_device_id ssd1307fb_of_match[] = {
	{
		.compatible = "solomon,ssd1306fb-i2c",
		.data = (void *)&ssd1307fb_ssd1306_ops,
	},
	{
		.compatible = "solomon,ssd1307fb-i2c",
		.data = (void *)&ssd1307fb_ssd1307_ops,
	},
	{},
};
MODULE_DEVICE_TABLE(of, ssd1307fb_of_match);

static int ssd1307fb_probe(struct i2c_client *client,
			   const struct i2c_device_id *id)
{
	struct fb_info *info;
	struct device_node *node = client->dev.of_node;
	u32 vmem_size;
	struct ssd1307fb_par *par;
	u8 *vmem;
	int ret;

	if (!node) {
		dev_err(&client->dev, "No device tree data found!\n");
		return -EINVAL;
	}

	info = framebuffer_alloc(sizeof(struct ssd1307fb_par), &client->dev);
	if (!info) {
		dev_err(&client->dev, "Couldn't allocate framebuffer.\n");
		return -ENOMEM;
	}

	par = info->par;
	par->info = info;
	par->client = client;

	par->ops = (struct ssd1307fb_ops *)of_match_device(ssd1307fb_of_match,
							   &client->dev)->data;

	par->reset = of_get_named_gpio(client->dev.of_node,
					 "reset-gpios", 0);
	if (!gpio_is_valid(par->reset)) {
		ret = -EINVAL;
		goto fb_alloc_error;
	}

	if (of_property_read_u32(node, "solomon,width", &par->width))
		par->width = 96;

	if (of_property_read_u32(node, "solomon,height", &par->height))
		par->width = 16;

	if (of_property_read_u32(node, "solomon,page-offset", &par->page_offset))
		par->page_offset = 1;

	vmem_size = par->width * par->height / 8;

	vmem = devm_kzalloc(&client->dev, vmem_size, GFP_KERNEL);
	if (!vmem) {
		dev_err(&client->dev, "Couldn't allocate graphical memory.\n");
		ret = -ENOMEM;
		goto fb_alloc_error;
	}

	info->fbops = &ssd1307fb_ops;
	info->fix = ssd1307fb_fix;
	info->fix.line_length = par->width / 8;
	info->fbdefio = &ssd1307fb_defio;

	info->var = ssd1307fb_var;
	info->var.xres = par->width;
	info->var.xres_virtual = par->width;
	info->var.yres = par->height;
	info->var.yres_virtual = par->height;

	info->var.red.length = 1;
	info->var.red.offset = 0;
	info->var.green.length = 1;
	info->var.green.offset = 0;
	info->var.blue.length = 1;
	info->var.blue.offset = 0;

	info->screen_base = (u8 __force __iomem *)vmem;
	info->fix.smem_start = (unsigned long)vmem;
	info->fix.smem_len = vmem_size;

	fb_deferred_io_init(info);

	ret = devm_gpio_request_one(&client->dev, par->reset,
				    GPIOF_OUT_INIT_HIGH,
				    "oled-reset");
	if (ret) {
		dev_err(&client->dev,
			"failed to request gpio %d: %d\n",
			par->reset, ret);
		goto reset_oled_error;
	}

	i2c_set_clientdata(client, info);

	/* Reset the screen */
	gpio_set_value(par->reset, 0);
	udelay(4);
	gpio_set_value(par->reset, 1);
	udelay(4);

	if (par->ops->init) {
		ret = par->ops->init(par);
		if (ret)
			goto reset_oled_error;
	}

	ret = register_framebuffer(info);
	if (ret) {
		dev_err(&client->dev, "Couldn't register the framebuffer\n");
		goto panel_init_error;
	}

	dev_info(&client->dev, "fb%d: %s framebuffer device registered, using %d bytes of video memory\n", info->node, info->fix.id, vmem_size);

	return 0;

panel_init_error:
	if (par->ops->remove)
		par->ops->remove(par);
reset_oled_error:
	fb_deferred_io_cleanup(info);
fb_alloc_error:
	framebuffer_release(info);
	return ret;
}

static int ssd1307fb_remove(struct i2c_client *client)
{
	struct fb_info *info = i2c_get_clientdata(client);
	struct ssd1307fb_par *par = info->par;

	unregister_framebuffer(info);
	if (par->ops->remove)
		par->ops->remove(par);
	fb_deferred_io_cleanup(info);
	framebuffer_release(info);

	return 0;
}

static const struct i2c_device_id ssd1307fb_i2c_id[] = {
	{ "ssd1306fb", 0 },
	{ "ssd1307fb", 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, ssd1307fb_i2c_id);

static struct i2c_driver ssd1307fb_driver = {
	.probe = ssd1307fb_probe,
	.remove = ssd1307fb_remove,
	.id_table = ssd1307fb_i2c_id,
	.driver = {
		.name = "ssd1307fb",
		.of_match_table = of_match_ptr(ssd1307fb_of_match),
		.owner = THIS_MODULE,
	},
};

module_i2c_driver(ssd1307fb_driver);

MODULE_DESCRIPTION("FB driver for the Solomon SSD1307 OLED controller");
MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
MODULE_LICENSE("GPL");