xref: /linux/drivers/video/fbdev/ssd1307fb.c (revision 546b928da0427b0d6c663cbb992bd7bfa9ac7971)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Driver for the Solomon SSD1307 OLED controller
4  *
5  * Copyright 2012 Free Electrons
6  */
7 
8 #include <linux/backlight.h>
9 #include <linux/delay.h>
10 #include <linux/fb.h>
11 #include <linux/gpio/consumer.h>
12 #include <linux/i2c.h>
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/property.h>
16 #include <linux/pwm.h>
17 #include <linux/spinlock.h>
18 #include <linux/uaccess.h>
19 #include <linux/regulator/consumer.h>
20 
21 #define SSD1307FB_DATA			0x40
22 #define SSD1307FB_COMMAND		0x80
23 
24 #define SSD1307FB_SET_ADDRESS_MODE	0x20
25 #define SSD1307FB_SET_ADDRESS_MODE_HORIZONTAL	(0x00)
26 #define SSD1307FB_SET_ADDRESS_MODE_VERTICAL	(0x01)
27 #define SSD1307FB_SET_ADDRESS_MODE_PAGE		(0x02)
28 #define SSD1307FB_SET_COL_RANGE		0x21
29 #define SSD1307FB_SET_PAGE_RANGE	0x22
30 #define SSD1307FB_CONTRAST		0x81
31 #define SSD1307FB_SET_LOOKUP_TABLE	0x91
32 #define	SSD1307FB_CHARGE_PUMP		0x8d
33 #define SSD1307FB_SEG_REMAP_ON		0xa1
34 #define SSD1307FB_DISPLAY_OFF		0xae
35 #define SSD1307FB_SET_MULTIPLEX_RATIO	0xa8
36 #define SSD1307FB_DISPLAY_ON		0xaf
37 #define SSD1307FB_START_PAGE_ADDRESS	0xb0
38 #define SSD1307FB_SET_DISPLAY_OFFSET	0xd3
39 #define	SSD1307FB_SET_CLOCK_FREQ	0xd5
40 #define	SSD1307FB_SET_AREA_COLOR_MODE	0xd8
41 #define	SSD1307FB_SET_PRECHARGE_PERIOD	0xd9
42 #define	SSD1307FB_SET_COM_PINS_CONFIG	0xda
43 #define	SSD1307FB_SET_VCOMH		0xdb
44 
45 #define MAX_CONTRAST 255
46 
47 #define REFRESHRATE 1
48 
49 static u_int refreshrate = REFRESHRATE;
50 module_param(refreshrate, uint, 0);
51 
52 struct ssd1307fb_deviceinfo {
53 	u32 default_vcomh;
54 	u32 default_dclk_div;
55 	u32 default_dclk_frq;
56 	bool need_pwm;
57 	bool need_chargepump;
58 };
59 
60 struct ssd1307fb_par {
61 	unsigned area_color_enable : 1;
62 	unsigned com_invdir : 1;
63 	unsigned com_lrremap : 1;
64 	unsigned com_seq : 1;
65 	unsigned lookup_table_set : 1;
66 	unsigned low_power : 1;
67 	unsigned seg_remap : 1;
68 	u32 com_offset;
69 	u32 contrast;
70 	u32 dclk_div;
71 	u32 dclk_frq;
72 	const struct ssd1307fb_deviceinfo *device_info;
73 	struct i2c_client *client;
74 	u32 height;
75 	struct fb_info *info;
76 	/* Pending damage, with exclusive x2/y2, protected by damage_lock. */
77 	spinlock_t damage_lock;
78 	bool damage_pending;
79 	u32 damage_x1;
80 	u32 damage_x2;
81 	u32 damage_y1;
82 	u32 damage_y2;
83 	u8 lookup_table[4];
84 	u32 page_offset;
85 	u32 col_offset;
86 	u32 prechargep1;
87 	u32 prechargep2;
88 	struct pwm_device *pwm;
89 	struct gpio_desc *reset;
90 	struct regulator *vbat_reg;
91 	u32 vcomh;
92 	u32 width;
93 	/* Cached address ranges */
94 	u8 col_start;
95 	u8 col_end;
96 	u8 page_start;
97 	u8 page_end;
98 };
99 
100 struct ssd1307fb_array {
101 	u8	type;
102 	u8	data[];
103 };
104 
105 static const struct fb_fix_screeninfo ssd1307fb_fix = {
106 	.id		= "Solomon SSD1307",
107 	.type		= FB_TYPE_PACKED_PIXELS,
108 	.visual		= FB_VISUAL_MONO10,
109 	.xpanstep	= 0,
110 	.ypanstep	= 0,
111 	.ywrapstep	= 0,
112 	.accel		= FB_ACCEL_NONE,
113 };
114 
115 static const struct fb_var_screeninfo ssd1307fb_var = {
116 	.bits_per_pixel	= 1,
117 	.red = { .length = 1 },
118 	.green = { .length = 1 },
119 	.blue = { .length = 1 },
120 };
121 
ssd1307fb_alloc_array(u32 len,u8 type)122 static struct ssd1307fb_array *ssd1307fb_alloc_array(u32 len, u8 type)
123 {
124 	struct ssd1307fb_array *array;
125 
126 	array = kzalloc(sizeof(struct ssd1307fb_array) + len, GFP_KERNEL);
127 	if (!array)
128 		return NULL;
129 
130 	array->type = type;
131 
132 	return array;
133 }
134 
ssd1307fb_write_array(struct i2c_client * client,struct ssd1307fb_array * array,u32 len)135 static int ssd1307fb_write_array(struct i2c_client *client,
136 				 struct ssd1307fb_array *array, u32 len)
137 {
138 	int ret;
139 
140 	len += sizeof(struct ssd1307fb_array);
141 
142 	ret = i2c_master_send(client, (u8 *)array, len);
143 	if (ret != len) {
144 		dev_err(&client->dev, "Couldn't send I2C command.\n");
145 		return ret;
146 	}
147 
148 	return 0;
149 }
150 
ssd1307fb_write_cmd(struct i2c_client * client,u8 cmd)151 static inline int ssd1307fb_write_cmd(struct i2c_client *client, u8 cmd)
152 {
153 	struct ssd1307fb_array *array;
154 	int ret;
155 
156 	array = ssd1307fb_alloc_array(1, SSD1307FB_COMMAND);
157 	if (!array)
158 		return -ENOMEM;
159 
160 	array->data[0] = cmd;
161 
162 	ret = ssd1307fb_write_array(client, array, 1);
163 	kfree(array);
164 
165 	return ret;
166 }
167 
ssd1307fb_set_col_range(struct ssd1307fb_par * par,u8 col_start,u8 cols)168 static int ssd1307fb_set_col_range(struct ssd1307fb_par *par, u8 col_start,
169 				   u8 cols)
170 {
171 	u8 col_end = col_start + cols - 1;
172 	int ret;
173 
174 	if (col_start == par->col_start && col_end == par->col_end)
175 		return 0;
176 
177 	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_COL_RANGE);
178 	if (ret < 0)
179 		return ret;
180 
181 	ret = ssd1307fb_write_cmd(par->client, col_start);
182 	if (ret < 0)
183 		return ret;
184 
185 	ret = ssd1307fb_write_cmd(par->client, col_end);
186 	if (ret < 0)
187 		return ret;
188 
189 	par->col_start = col_start;
190 	par->col_end = col_end;
191 	return 0;
192 }
193 
ssd1307fb_set_page_range(struct ssd1307fb_par * par,u8 page_start,u8 pages)194 static int ssd1307fb_set_page_range(struct ssd1307fb_par *par, u8 page_start,
195 				    u8 pages)
196 {
197 	u8 page_end = page_start + pages - 1;
198 	int ret;
199 
200 	if (page_start == par->page_start && page_end == par->page_end)
201 		return 0;
202 
203 	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_PAGE_RANGE);
204 	if (ret < 0)
205 		return ret;
206 
207 	ret = ssd1307fb_write_cmd(par->client, page_start);
208 	if (ret < 0)
209 		return ret;
210 
211 	ret = ssd1307fb_write_cmd(par->client, page_end);
212 	if (ret < 0)
213 		return ret;
214 
215 	par->page_start = page_start;
216 	par->page_end = page_end;
217 	return 0;
218 }
219 
ssd1307fb_update_rect(struct ssd1307fb_par * par,unsigned int x,unsigned int y,unsigned int width,unsigned int height)220 static int ssd1307fb_update_rect(struct ssd1307fb_par *par, unsigned int x,
221 				 unsigned int y, unsigned int width,
222 				 unsigned int height)
223 {
224 	struct ssd1307fb_array *array;
225 	u8 *vmem = par->info->screen_buffer;
226 	unsigned int line_length = par->info->fix.line_length;
227 	unsigned int pages = DIV_ROUND_UP(y % 8 + height, 8);
228 	u32 array_idx = 0;
229 	int ret, i, j, k;
230 
231 	array = ssd1307fb_alloc_array(width * pages, SSD1307FB_DATA);
232 	if (!array)
233 		return -ENOMEM;
234 
235 	/*
236 	 * The screen is divided in pages, each having a height of 8
237 	 * pixels, and the width of the screen. When sending a byte of
238 	 * data to the controller, it gives the 8 bits for the current
239 	 * column. I.e, the first byte are the 8 bits of the first
240 	 * column, then the 8 bits for the second column, etc.
241 	 *
242 	 *
243 	 * Representation of the screen, assuming it is 5 bits
244 	 * wide. Each letter-number combination is a bit that controls
245 	 * one pixel.
246 	 *
247 	 * A0 A1 A2 A3 A4
248 	 * B0 B1 B2 B3 B4
249 	 * C0 C1 C2 C3 C4
250 	 * D0 D1 D2 D3 D4
251 	 * E0 E1 E2 E3 E4
252 	 * F0 F1 F2 F3 F4
253 	 * G0 G1 G2 G3 G4
254 	 * H0 H1 H2 H3 H4
255 	 *
256 	 * If you want to update this screen, you need to send 5 bytes:
257 	 *  (1) A0 B0 C0 D0 E0 F0 G0 H0
258 	 *  (2) A1 B1 C1 D1 E1 F1 G1 H1
259 	 *  (3) A2 B2 C2 D2 E2 F2 G2 H2
260 	 *  (4) A3 B3 C3 D3 E3 F3 G3 H3
261 	 *  (5) A4 B4 C4 D4 E4 F4 G4 H4
262 	 */
263 
264 	ret = ssd1307fb_set_col_range(par, par->col_offset + x, width);
265 	if (ret < 0)
266 		goto out_free;
267 
268 	ret = ssd1307fb_set_page_range(par, par->page_offset + y / 8, pages);
269 	if (ret < 0)
270 		goto out_free;
271 
272 	for (i = y / 8; i < y / 8 + pages; i++) {
273 		int m = 8;
274 
275 		/* Last page may be partial */
276 		if (8 * (i + 1) > par->height)
277 			m = par->height % 8;
278 		for (j = x; j < x + width; j++) {
279 			u8 data = 0;
280 
281 			for (k = 0; k < m; k++) {
282 				u8 byte = vmem[(8 * i + k) * line_length +
283 					       j / 8];
284 				u8 bit = (byte >> (j % 8)) & 1;
285 				data |= bit << k;
286 			}
287 			array->data[array_idx++] = data;
288 		}
289 	}
290 
291 	ret = ssd1307fb_write_array(par->client, array, width * pages);
292 
293 out_free:
294 	kfree(array);
295 	return ret;
296 }
297 
ssd1307fb_update_display(struct ssd1307fb_par * par)298 static int ssd1307fb_update_display(struct ssd1307fb_par *par)
299 {
300 	return ssd1307fb_update_rect(par, 0, 0, par->width, par->height);
301 }
302 
ssd1307fb_blank(int blank_mode,struct fb_info * info)303 static int ssd1307fb_blank(int blank_mode, struct fb_info *info)
304 {
305 	struct ssd1307fb_par *par = info->par;
306 
307 	if (blank_mode != FB_BLANK_UNBLANK)
308 		return ssd1307fb_write_cmd(par->client, SSD1307FB_DISPLAY_OFF);
309 	else
310 		return ssd1307fb_write_cmd(par->client, SSD1307FB_DISPLAY_ON);
311 }
312 
ssd1307fb_schedule_damage(struct fb_info * info,u32 x,u32 y,u32 width,u32 height)313 static void ssd1307fb_schedule_damage(struct fb_info *info, u32 x, u32 y,
314 				      u32 width, u32 height)
315 {
316 	struct ssd1307fb_par *par = info->par;
317 	unsigned long flags;
318 	u32 x2, y2;
319 
320 	if (!width || !height || x >= par->width || y >= par->height)
321 		return;
322 
323 	x2 = x + min(width, par->width - x);
324 	y2 = y + min(height, par->height - y);
325 
326 	spin_lock_irqsave(&par->damage_lock, flags);
327 	if (par->damage_pending) {
328 		par->damage_x1 = min(par->damage_x1, x);
329 		par->damage_y1 = min(par->damage_y1, y);
330 		par->damage_x2 = max(par->damage_x2, x2);
331 		par->damage_y2 = max(par->damage_y2, y2);
332 	} else {
333 		par->damage_x1 = x;
334 		par->damage_y1 = y;
335 		par->damage_x2 = x2;
336 		par->damage_y2 = y2;
337 		par->damage_pending = true;
338 	}
339 	spin_unlock_irqrestore(&par->damage_lock, flags);
340 
341 	/* Advance an already-pending mmap update as well. */
342 	mod_delayed_work(system_wq, &info->deferred_work, 0);
343 }
344 
ssd1307fb_defio_damage_range(struct fb_info * info,off_t off,size_t len)345 static void ssd1307fb_defio_damage_range(struct fb_info *info, off_t off, size_t len)
346 {
347 	struct ssd1307fb_par *par = info->par;
348 
349 	ssd1307fb_schedule_damage(info, 0, 0, par->width, par->height);
350 }
351 
ssd1307fb_defio_damage_area(struct fb_info * info,u32 x,u32 y,u32 width,u32 height)352 static void ssd1307fb_defio_damage_area(struct fb_info *info, u32 x, u32 y,
353 					u32 width, u32 height)
354 {
355 	ssd1307fb_schedule_damage(info, x, y, width, height);
356 }
357 
358 FB_GEN_DEFAULT_DEFERRED_SYSMEM_OPS(ssd1307fb,
359 				   ssd1307fb_defio_damage_range,
360 				   ssd1307fb_defio_damage_area)
361 
362 static const struct fb_ops ssd1307fb_ops = {
363 	.owner		= THIS_MODULE,
364 	FB_DEFAULT_DEFERRED_OPS(ssd1307fb),
365 	.fb_blank	= ssd1307fb_blank,
366 };
367 
ssd1307fb_deferred_io(struct fb_info * info,struct list_head * pagereflist)368 static void ssd1307fb_deferred_io(struct fb_info *info, struct list_head *pagereflist)
369 {
370 	struct ssd1307fb_par *par = info->par;
371 	unsigned long flags;
372 	u32 x, y, width, height;
373 
374 	spin_lock_irqsave(&par->damage_lock, flags);
375 	if (!list_empty(pagereflist)) {
376 		x = 0;
377 		y = 0;
378 		width = par->width;
379 		height = par->height;
380 		par->damage_pending = false;
381 	} else if (par->damage_pending) {
382 		x = par->damage_x1;
383 		y = par->damage_y1;
384 		width = par->damage_x2 - par->damage_x1;
385 		height = par->damage_y2 - par->damage_y1;
386 		par->damage_pending = false;
387 	} else {
388 		spin_unlock_irqrestore(&par->damage_lock, flags);
389 		return;
390 	}
391 	spin_unlock_irqrestore(&par->damage_lock, flags);
392 
393 	ssd1307fb_update_rect(par, x, y, width, height);
394 }
395 
ssd1307fb_init(struct ssd1307fb_par * par)396 static int ssd1307fb_init(struct ssd1307fb_par *par)
397 {
398 	struct pwm_state pwmstate;
399 	int ret;
400 	u32 precharge, dclk, com_invdir, compins;
401 
402 	if (par->device_info->need_pwm) {
403 		par->pwm = pwm_get(&par->client->dev, NULL);
404 		if (IS_ERR(par->pwm)) {
405 			dev_err(&par->client->dev, "Could not get PWM from device tree!\n");
406 			return PTR_ERR(par->pwm);
407 		}
408 
409 		pwm_init_state(par->pwm, &pwmstate);
410 		pwm_set_relative_duty_cycle(&pwmstate, 50, 100);
411 		pwm_apply_might_sleep(par->pwm, &pwmstate);
412 
413 		/* Enable the PWM */
414 		pwm_enable(par->pwm);
415 
416 		dev_dbg(&par->client->dev, "Using PWM %s with a %lluns period.\n",
417 			par->pwm->label, pwm_get_period(par->pwm));
418 	}
419 
420 	/* Set initial contrast */
421 	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_CONTRAST);
422 	if (ret < 0)
423 		return ret;
424 
425 	ret = ssd1307fb_write_cmd(par->client, par->contrast);
426 	if (ret < 0)
427 		return ret;
428 
429 	/* Set segment re-map */
430 	if (par->seg_remap) {
431 		ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SEG_REMAP_ON);
432 		if (ret < 0)
433 			return ret;
434 	}
435 
436 	/* Set COM direction */
437 	com_invdir = 0xc0 | par->com_invdir << 3;
438 	ret = ssd1307fb_write_cmd(par->client,  com_invdir);
439 	if (ret < 0)
440 		return ret;
441 
442 	/* Set multiplex ratio value */
443 	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_MULTIPLEX_RATIO);
444 	if (ret < 0)
445 		return ret;
446 
447 	ret = ssd1307fb_write_cmd(par->client, par->height - 1);
448 	if (ret < 0)
449 		return ret;
450 
451 	/* set display offset value */
452 	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_DISPLAY_OFFSET);
453 	if (ret < 0)
454 		return ret;
455 
456 	ret = ssd1307fb_write_cmd(par->client, par->com_offset);
457 	if (ret < 0)
458 		return ret;
459 
460 	/* Set clock frequency */
461 	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_CLOCK_FREQ);
462 	if (ret < 0)
463 		return ret;
464 
465 	dclk = ((par->dclk_div - 1) & 0xf) | (par->dclk_frq & 0xf) << 4;
466 	ret = ssd1307fb_write_cmd(par->client, dclk);
467 	if (ret < 0)
468 		return ret;
469 
470 	/* Set Area Color Mode ON/OFF & Low Power Display Mode */
471 	if (par->area_color_enable || par->low_power) {
472 		u32 mode;
473 
474 		ret = ssd1307fb_write_cmd(par->client,
475 					  SSD1307FB_SET_AREA_COLOR_MODE);
476 		if (ret < 0)
477 			return ret;
478 
479 		mode = (par->area_color_enable ? 0x30 : 0) |
480 			(par->low_power ? 5 : 0);
481 		ret = ssd1307fb_write_cmd(par->client, mode);
482 		if (ret < 0)
483 			return ret;
484 	}
485 
486 	/* Set precharge period in number of ticks from the internal clock */
487 	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_PRECHARGE_PERIOD);
488 	if (ret < 0)
489 		return ret;
490 
491 	precharge = (par->prechargep1 & 0xf) | (par->prechargep2 & 0xf) << 4;
492 	ret = ssd1307fb_write_cmd(par->client, precharge);
493 	if (ret < 0)
494 		return ret;
495 
496 	/* Set COM pins configuration */
497 	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_COM_PINS_CONFIG);
498 	if (ret < 0)
499 		return ret;
500 
501 	compins = 0x02 | !par->com_seq << 4 | par->com_lrremap << 5;
502 	ret = ssd1307fb_write_cmd(par->client, compins);
503 	if (ret < 0)
504 		return ret;
505 
506 	/* Set VCOMH */
507 	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_VCOMH);
508 	if (ret < 0)
509 		return ret;
510 
511 	ret = ssd1307fb_write_cmd(par->client, par->vcomh);
512 	if (ret < 0)
513 		return ret;
514 
515 	/* Turn on the DC-DC Charge Pump */
516 	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_CHARGE_PUMP);
517 	if (ret < 0)
518 		return ret;
519 
520 	ret = ssd1307fb_write_cmd(par->client,
521 		BIT(4) | (par->device_info->need_chargepump ? BIT(2) : 0));
522 	if (ret < 0)
523 		return ret;
524 
525 	/* Set lookup table */
526 	if (par->lookup_table_set) {
527 		int i;
528 
529 		ret = ssd1307fb_write_cmd(par->client,
530 					  SSD1307FB_SET_LOOKUP_TABLE);
531 		if (ret < 0)
532 			return ret;
533 
534 		for (i = 0; i < ARRAY_SIZE(par->lookup_table); ++i) {
535 			u8 val = par->lookup_table[i];
536 
537 			if (val < 31 || val > 63)
538 				dev_warn(&par->client->dev,
539 					 "lookup table index %d value out of range 31 <= %d <= 63\n",
540 					 i, val);
541 			ret = ssd1307fb_write_cmd(par->client, val);
542 			if (ret < 0)
543 				return ret;
544 		}
545 	}
546 
547 	/* Switch to horizontal addressing mode */
548 	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_ADDRESS_MODE);
549 	if (ret < 0)
550 		return ret;
551 
552 	ret = ssd1307fb_write_cmd(par->client,
553 				  SSD1307FB_SET_ADDRESS_MODE_HORIZONTAL);
554 	if (ret < 0)
555 		return ret;
556 
557 	/* Clear the screen */
558 	ret = ssd1307fb_update_display(par);
559 	if (ret < 0)
560 		return ret;
561 
562 	/* Turn on the display */
563 	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_DISPLAY_ON);
564 	if (ret < 0)
565 		return ret;
566 
567 	return 0;
568 }
569 
ssd1307fb_update_bl(struct backlight_device * bdev)570 static int ssd1307fb_update_bl(struct backlight_device *bdev)
571 {
572 	struct ssd1307fb_par *par = bl_get_data(bdev);
573 	int ret;
574 	int brightness = bdev->props.brightness;
575 
576 	par->contrast = brightness;
577 
578 	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_CONTRAST);
579 	if (ret < 0)
580 		return ret;
581 	ret = ssd1307fb_write_cmd(par->client, par->contrast);
582 	if (ret < 0)
583 		return ret;
584 	return 0;
585 }
586 
ssd1307fb_get_brightness(struct backlight_device * bdev)587 static int ssd1307fb_get_brightness(struct backlight_device *bdev)
588 {
589 	struct ssd1307fb_par *par = bl_get_data(bdev);
590 
591 	return par->contrast;
592 }
593 
594 static const struct backlight_ops ssd1307fb_bl_ops = {
595 	.options	= BL_CORE_SUSPENDRESUME,
596 	.update_status	= ssd1307fb_update_bl,
597 	.get_brightness	= ssd1307fb_get_brightness,
598 };
599 
600 static struct ssd1307fb_deviceinfo ssd1307fb_ssd1305_deviceinfo = {
601 	.default_vcomh = 0x34,
602 	.default_dclk_div = 1,
603 	.default_dclk_frq = 7,
604 };
605 
606 static struct ssd1307fb_deviceinfo ssd1307fb_ssd1306_deviceinfo = {
607 	.default_vcomh = 0x20,
608 	.default_dclk_div = 1,
609 	.default_dclk_frq = 8,
610 	.need_chargepump = 1,
611 };
612 
613 static struct ssd1307fb_deviceinfo ssd1307fb_ssd1307_deviceinfo = {
614 	.default_vcomh = 0x20,
615 	.default_dclk_div = 2,
616 	.default_dclk_frq = 12,
617 	.need_pwm = 1,
618 };
619 
620 static struct ssd1307fb_deviceinfo ssd1307fb_ssd1309_deviceinfo = {
621 	.default_vcomh = 0x34,
622 	.default_dclk_div = 1,
623 	.default_dclk_frq = 10,
624 };
625 
626 static const struct of_device_id ssd1307fb_of_match[] = {
627 	{
628 		.compatible = "solomon,ssd1305fb-i2c",
629 		.data = (void *)&ssd1307fb_ssd1305_deviceinfo,
630 	},
631 	{
632 		.compatible = "solomon,ssd1306fb-i2c",
633 		.data = (void *)&ssd1307fb_ssd1306_deviceinfo,
634 	},
635 	{
636 		.compatible = "solomon,ssd1307fb-i2c",
637 		.data = (void *)&ssd1307fb_ssd1307_deviceinfo,
638 	},
639 	{
640 		.compatible = "solomon,ssd1309fb-i2c",
641 		.data = (void *)&ssd1307fb_ssd1309_deviceinfo,
642 	},
643 	{},
644 };
645 MODULE_DEVICE_TABLE(of, ssd1307fb_of_match);
646 
ssd1307fb_probe(struct i2c_client * client)647 static int ssd1307fb_probe(struct i2c_client *client)
648 {
649 	struct device *dev = &client->dev;
650 	struct backlight_device *bl;
651 	struct fb_info *info;
652 	struct fb_deferred_io *ssd1307fb_defio;
653 	u32 vmem_size;
654 	struct ssd1307fb_par *par;
655 	void *vmem;
656 	int ret;
657 
658 	info = framebuffer_alloc(sizeof(struct ssd1307fb_par), dev);
659 	if (!info)
660 		return -ENOMEM;
661 
662 	par = info->par;
663 	par->info = info;
664 	par->client = client;
665 	spin_lock_init(&par->damage_lock);
666 
667 	par->device_info = device_get_match_data(dev);
668 	if (!par->device_info) {
669 		ret = -ENODEV;
670 		goto fb_alloc_error;
671 	}
672 
673 	par->reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
674 	if (IS_ERR(par->reset)) {
675 		ret = dev_err_probe(dev, PTR_ERR(par->reset),
676 				    "failed to get reset gpio\n");
677 		goto fb_alloc_error;
678 	}
679 
680 	par->vbat_reg = devm_regulator_get_optional(dev, "vbat");
681 	if (IS_ERR(par->vbat_reg)) {
682 		ret = PTR_ERR(par->vbat_reg);
683 		if (ret == -ENODEV) {
684 			par->vbat_reg = NULL;
685 		} else {
686 			dev_err_probe(dev, ret, "failed to get VBAT regulator\n");
687 			goto fb_alloc_error;
688 		}
689 	}
690 
691 	if (device_property_read_u32(dev, "solomon,width", &par->width))
692 		par->width = 96;
693 
694 	if (device_property_read_u32(dev, "solomon,height", &par->height))
695 		par->height = 16;
696 
697 	if (device_property_read_u32(dev, "solomon,page-offset", &par->page_offset))
698 		par->page_offset = 1;
699 
700 	if (device_property_read_u32(dev, "solomon,col-offset", &par->col_offset))
701 		par->col_offset = 0;
702 
703 	if (device_property_read_u32(dev, "solomon,com-offset", &par->com_offset))
704 		par->com_offset = 0;
705 
706 	if (device_property_read_u32(dev, "solomon,prechargep1", &par->prechargep1))
707 		par->prechargep1 = 2;
708 
709 	if (device_property_read_u32(dev, "solomon,prechargep2", &par->prechargep2))
710 		par->prechargep2 = 2;
711 
712 	if (!device_property_read_u8_array(dev, "solomon,lookup-table",
713 					   par->lookup_table,
714 					   ARRAY_SIZE(par->lookup_table)))
715 		par->lookup_table_set = 1;
716 
717 	par->seg_remap = !device_property_read_bool(dev, "solomon,segment-no-remap");
718 	par->com_seq = device_property_read_bool(dev, "solomon,com-seq");
719 	par->com_lrremap = device_property_read_bool(dev, "solomon,com-lrremap");
720 	par->com_invdir = device_property_read_bool(dev, "solomon,com-invdir");
721 	par->area_color_enable =
722 		device_property_read_bool(dev, "solomon,area-color-enable");
723 	par->low_power = device_property_read_bool(dev, "solomon,low-power");
724 
725 	par->contrast = 127;
726 	par->vcomh = par->device_info->default_vcomh;
727 
728 	/* Setup display timing */
729 	if (device_property_read_u32(dev, "solomon,dclk-div", &par->dclk_div))
730 		par->dclk_div = par->device_info->default_dclk_div;
731 	if (device_property_read_u32(dev, "solomon,dclk-frq", &par->dclk_frq))
732 		par->dclk_frq = par->device_info->default_dclk_frq;
733 
734 	vmem_size = DIV_ROUND_UP(par->width, 8) * par->height;
735 
736 	vmem = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
737 					get_order(vmem_size));
738 	if (!vmem) {
739 		dev_err(dev, "Couldn't allocate graphical memory.\n");
740 		ret = -ENOMEM;
741 		goto fb_alloc_error;
742 	}
743 
744 	ssd1307fb_defio = devm_kzalloc(dev, sizeof(*ssd1307fb_defio),
745 				       GFP_KERNEL);
746 	if (!ssd1307fb_defio) {
747 		dev_err(dev, "Couldn't allocate deferred io.\n");
748 		ret = -ENOMEM;
749 		goto fb_defio_error;
750 	}
751 
752 	ssd1307fb_defio->delay = HZ / refreshrate;
753 	ssd1307fb_defio->deferred_io = ssd1307fb_deferred_io;
754 
755 	info->fbops = &ssd1307fb_ops;
756 	info->fix = ssd1307fb_fix;
757 	info->fix.line_length = DIV_ROUND_UP(par->width, 8);
758 	info->fbdefio = ssd1307fb_defio;
759 
760 	info->var = ssd1307fb_var;
761 	info->var.xres = par->width;
762 	info->var.xres_virtual = par->width;
763 	info->var.yres = par->height;
764 	info->var.yres_virtual = par->height;
765 
766 	info->screen_buffer = vmem;
767 	info->fix.smem_start = __pa(vmem);
768 	info->fix.smem_len = vmem_size;
769 
770 	fb_deferred_io_init(info);
771 
772 	i2c_set_clientdata(client, info);
773 
774 	if (par->reset) {
775 		/* Reset the screen */
776 		gpiod_set_value_cansleep(par->reset, 1);
777 		udelay(4);
778 		gpiod_set_value_cansleep(par->reset, 0);
779 		udelay(4);
780 	}
781 
782 	if (par->vbat_reg) {
783 		ret = regulator_enable(par->vbat_reg);
784 		if (ret) {
785 			dev_err(dev, "failed to enable VBAT: %d\n", ret);
786 			goto reset_oled_error;
787 		}
788 	}
789 
790 	ret = ssd1307fb_init(par);
791 	if (ret)
792 		goto regulator_enable_error;
793 
794 	bl = backlight_device_register("ssd1307fb-bl", dev, par, &ssd1307fb_bl_ops,
795 				       NULL);
796 	if (IS_ERR(bl)) {
797 		ret = PTR_ERR(bl);
798 		dev_err(dev, "unable to register backlight device: %d\n", ret);
799 		goto panel_init_error;
800 	}
801 	info->bl_dev = bl;
802 
803 	ret = register_framebuffer(info);
804 	if (ret) {
805 		dev_err(dev, "Couldn't register the framebuffer\n");
806 		goto fb_init_error;
807 	}
808 
809 	bl->props.brightness = par->contrast;
810 	bl->props.max_brightness = MAX_CONTRAST;
811 
812 	dev_info(dev, "fb%d: %s framebuffer device registered, using %d bytes of video memory\n", info->node, info->fix.id, vmem_size);
813 
814 	return 0;
815 
816 fb_init_error:
817 	backlight_device_unregister(bl);
818 panel_init_error:
819 	pwm_disable(par->pwm);
820 	pwm_put(par->pwm);
821 regulator_enable_error:
822 	if (par->vbat_reg)
823 		regulator_disable(par->vbat_reg);
824 reset_oled_error:
825 	fb_deferred_io_cleanup(info);
826 fb_defio_error:
827 	__free_pages(vmem, get_order(vmem_size));
828 fb_alloc_error:
829 	framebuffer_release(info);
830 	return ret;
831 }
832 
ssd1307fb_remove(struct i2c_client * client)833 static void ssd1307fb_remove(struct i2c_client *client)
834 {
835 	struct fb_info *info = i2c_get_clientdata(client);
836 	struct ssd1307fb_par *par = info->par;
837 
838 	ssd1307fb_write_cmd(par->client, SSD1307FB_DISPLAY_OFF);
839 
840 	backlight_device_unregister(info->bl_dev);
841 
842 	unregister_framebuffer(info);
843 	pwm_disable(par->pwm);
844 	pwm_put(par->pwm);
845 	if (par->vbat_reg)
846 		regulator_disable(par->vbat_reg);
847 	fb_deferred_io_cleanup(info);
848 	__free_pages(__va(info->fix.smem_start), get_order(info->fix.smem_len));
849 	framebuffer_release(info);
850 }
851 
852 static const struct i2c_device_id ssd1307fb_i2c_id[] = {
853 	{ .name = "ssd1305fb" },
854 	{ .name = "ssd1306fb" },
855 	{ .name = "ssd1307fb" },
856 	{ .name = "ssd1309fb" },
857 	{ }
858 };
859 MODULE_DEVICE_TABLE(i2c, ssd1307fb_i2c_id);
860 
861 static struct i2c_driver ssd1307fb_driver = {
862 	.probe = ssd1307fb_probe,
863 	.remove = ssd1307fb_remove,
864 	.id_table = ssd1307fb_i2c_id,
865 	.driver = {
866 		.name = "ssd1307fb",
867 		.of_match_table = ssd1307fb_of_match,
868 	},
869 };
870 
871 module_i2c_driver(ssd1307fb_driver);
872 
873 MODULE_DESCRIPTION("FB driver for the Solomon SSD1307 OLED controller");
874 MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
875 MODULE_LICENSE("GPL");
876