xref: /openbmc/linux/drivers/video/fbdev/ssd1307fb.c (revision a10c3d5f)
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/uaccess.h>
18 #include <linux/regulator/consumer.h>
19 
20 #define SSD1307FB_DATA			0x40
21 #define SSD1307FB_COMMAND		0x80
22 
23 #define SSD1307FB_SET_ADDRESS_MODE	0x20
24 #define SSD1307FB_SET_ADDRESS_MODE_HORIZONTAL	(0x00)
25 #define SSD1307FB_SET_ADDRESS_MODE_VERTICAL	(0x01)
26 #define SSD1307FB_SET_ADDRESS_MODE_PAGE		(0x02)
27 #define SSD1307FB_SET_COL_RANGE		0x21
28 #define SSD1307FB_SET_PAGE_RANGE	0x22
29 #define SSD1307FB_CONTRAST		0x81
30 #define SSD1307FB_SET_LOOKUP_TABLE	0x91
31 #define	SSD1307FB_CHARGE_PUMP		0x8d
32 #define SSD1307FB_SEG_REMAP_ON		0xa1
33 #define SSD1307FB_DISPLAY_OFF		0xae
34 #define SSD1307FB_SET_MULTIPLEX_RATIO	0xa8
35 #define SSD1307FB_DISPLAY_ON		0xaf
36 #define SSD1307FB_START_PAGE_ADDRESS	0xb0
37 #define SSD1307FB_SET_DISPLAY_OFFSET	0xd3
38 #define	SSD1307FB_SET_CLOCK_FREQ	0xd5
39 #define	SSD1307FB_SET_AREA_COLOR_MODE	0xd8
40 #define	SSD1307FB_SET_PRECHARGE_PERIOD	0xd9
41 #define	SSD1307FB_SET_COM_PINS_CONFIG	0xda
42 #define	SSD1307FB_SET_VCOMH		0xdb
43 
44 #define MAX_CONTRAST 255
45 
46 #define REFRESHRATE 1
47 
48 static u_int refreshrate = REFRESHRATE;
49 module_param(refreshrate, uint, 0);
50 
51 struct ssd1307fb_deviceinfo {
52 	u32 default_vcomh;
53 	u32 default_dclk_div;
54 	u32 default_dclk_frq;
55 	bool need_pwm;
56 	bool need_chargepump;
57 };
58 
59 struct ssd1307fb_par {
60 	unsigned area_color_enable : 1;
61 	unsigned com_invdir : 1;
62 	unsigned com_lrremap : 1;
63 	unsigned com_seq : 1;
64 	unsigned lookup_table_set : 1;
65 	unsigned low_power : 1;
66 	unsigned seg_remap : 1;
67 	u32 com_offset;
68 	u32 contrast;
69 	u32 dclk_div;
70 	u32 dclk_frq;
71 	const struct ssd1307fb_deviceinfo *device_info;
72 	struct i2c_client *client;
73 	u32 height;
74 	struct fb_info *info;
75 	u8 lookup_table[4];
76 	u32 page_offset;
77 	u32 col_offset;
78 	u32 prechargep1;
79 	u32 prechargep2;
80 	struct pwm_device *pwm;
81 	struct gpio_desc *reset;
82 	struct regulator *vbat_reg;
83 	u32 vcomh;
84 	u32 width;
85 	/* Cached address ranges */
86 	u8 col_start;
87 	u8 col_end;
88 	u8 page_start;
89 	u8 page_end;
90 };
91 
92 struct ssd1307fb_array {
93 	u8	type;
94 	u8	data[];
95 };
96 
97 static const struct fb_fix_screeninfo ssd1307fb_fix = {
98 	.id		= "Solomon SSD1307",
99 	.type		= FB_TYPE_PACKED_PIXELS,
100 	.visual		= FB_VISUAL_MONO10,
101 	.xpanstep	= 0,
102 	.ypanstep	= 0,
103 	.ywrapstep	= 0,
104 	.accel		= FB_ACCEL_NONE,
105 };
106 
107 static const struct fb_var_screeninfo ssd1307fb_var = {
108 	.bits_per_pixel	= 1,
109 	.red = { .length = 1 },
110 	.green = { .length = 1 },
111 	.blue = { .length = 1 },
112 };
113 
ssd1307fb_alloc_array(u32 len,u8 type)114 static struct ssd1307fb_array *ssd1307fb_alloc_array(u32 len, u8 type)
115 {
116 	struct ssd1307fb_array *array;
117 
118 	array = kzalloc(sizeof(struct ssd1307fb_array) + len, GFP_KERNEL);
119 	if (!array)
120 		return NULL;
121 
122 	array->type = type;
123 
124 	return array;
125 }
126 
ssd1307fb_write_array(struct i2c_client * client,struct ssd1307fb_array * array,u32 len)127 static int ssd1307fb_write_array(struct i2c_client *client,
128 				 struct ssd1307fb_array *array, u32 len)
129 {
130 	int ret;
131 
132 	len += sizeof(struct ssd1307fb_array);
133 
134 	ret = i2c_master_send(client, (u8 *)array, len);
135 	if (ret != len) {
136 		dev_err(&client->dev, "Couldn't send I2C command.\n");
137 		return ret;
138 	}
139 
140 	return 0;
141 }
142 
ssd1307fb_write_cmd(struct i2c_client * client,u8 cmd)143 static inline int ssd1307fb_write_cmd(struct i2c_client *client, u8 cmd)
144 {
145 	struct ssd1307fb_array *array;
146 	int ret;
147 
148 	array = ssd1307fb_alloc_array(1, SSD1307FB_COMMAND);
149 	if (!array)
150 		return -ENOMEM;
151 
152 	array->data[0] = cmd;
153 
154 	ret = ssd1307fb_write_array(client, array, 1);
155 	kfree(array);
156 
157 	return ret;
158 }
159 
ssd1307fb_set_col_range(struct ssd1307fb_par * par,u8 col_start,u8 cols)160 static int ssd1307fb_set_col_range(struct ssd1307fb_par *par, u8 col_start,
161 				   u8 cols)
162 {
163 	u8 col_end = col_start + cols - 1;
164 	int ret;
165 
166 	if (col_start == par->col_start && col_end == par->col_end)
167 		return 0;
168 
169 	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_COL_RANGE);
170 	if (ret < 0)
171 		return ret;
172 
173 	ret = ssd1307fb_write_cmd(par->client, col_start);
174 	if (ret < 0)
175 		return ret;
176 
177 	ret = ssd1307fb_write_cmd(par->client, col_end);
178 	if (ret < 0)
179 		return ret;
180 
181 	par->col_start = col_start;
182 	par->col_end = col_end;
183 	return 0;
184 }
185 
ssd1307fb_set_page_range(struct ssd1307fb_par * par,u8 page_start,u8 pages)186 static int ssd1307fb_set_page_range(struct ssd1307fb_par *par, u8 page_start,
187 				    u8 pages)
188 {
189 	u8 page_end = page_start + pages - 1;
190 	int ret;
191 
192 	if (page_start == par->page_start && page_end == par->page_end)
193 		return 0;
194 
195 	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_PAGE_RANGE);
196 	if (ret < 0)
197 		return ret;
198 
199 	ret = ssd1307fb_write_cmd(par->client, page_start);
200 	if (ret < 0)
201 		return ret;
202 
203 	ret = ssd1307fb_write_cmd(par->client, page_end);
204 	if (ret < 0)
205 		return ret;
206 
207 	par->page_start = page_start;
208 	par->page_end = page_end;
209 	return 0;
210 }
211 
ssd1307fb_update_rect(struct ssd1307fb_par * par,unsigned int x,unsigned int y,unsigned int width,unsigned int height)212 static int ssd1307fb_update_rect(struct ssd1307fb_par *par, unsigned int x,
213 				 unsigned int y, unsigned int width,
214 				 unsigned int height)
215 {
216 	struct ssd1307fb_array *array;
217 	u8 *vmem = par->info->screen_buffer;
218 	unsigned int line_length = par->info->fix.line_length;
219 	unsigned int pages = DIV_ROUND_UP(y % 8 + height, 8);
220 	u32 array_idx = 0;
221 	int ret, i, j, k;
222 
223 	array = ssd1307fb_alloc_array(width * pages, SSD1307FB_DATA);
224 	if (!array)
225 		return -ENOMEM;
226 
227 	/*
228 	 * The screen is divided in pages, each having a height of 8
229 	 * pixels, and the width of the screen. When sending a byte of
230 	 * data to the controller, it gives the 8 bits for the current
231 	 * column. I.e, the first byte are the 8 bits of the first
232 	 * column, then the 8 bits for the second column, etc.
233 	 *
234 	 *
235 	 * Representation of the screen, assuming it is 5 bits
236 	 * wide. Each letter-number combination is a bit that controls
237 	 * one pixel.
238 	 *
239 	 * A0 A1 A2 A3 A4
240 	 * B0 B1 B2 B3 B4
241 	 * C0 C1 C2 C3 C4
242 	 * D0 D1 D2 D3 D4
243 	 * E0 E1 E2 E3 E4
244 	 * F0 F1 F2 F3 F4
245 	 * G0 G1 G2 G3 G4
246 	 * H0 H1 H2 H3 H4
247 	 *
248 	 * If you want to update this screen, you need to send 5 bytes:
249 	 *  (1) A0 B0 C0 D0 E0 F0 G0 H0
250 	 *  (2) A1 B1 C1 D1 E1 F1 G1 H1
251 	 *  (3) A2 B2 C2 D2 E2 F2 G2 H2
252 	 *  (4) A3 B3 C3 D3 E3 F3 G3 H3
253 	 *  (5) A4 B4 C4 D4 E4 F4 G4 H4
254 	 */
255 
256 	ret = ssd1307fb_set_col_range(par, par->col_offset + x, width);
257 	if (ret < 0)
258 		goto out_free;
259 
260 	ret = ssd1307fb_set_page_range(par, par->page_offset + y / 8, pages);
261 	if (ret < 0)
262 		goto out_free;
263 
264 	for (i = y / 8; i < y / 8 + pages; i++) {
265 		int m = 8;
266 
267 		/* Last page may be partial */
268 		if (8 * (i + 1) > par->height)
269 			m = par->height % 8;
270 		for (j = x; j < x + width; j++) {
271 			u8 data = 0;
272 
273 			for (k = 0; k < m; k++) {
274 				u8 byte = vmem[(8 * i + k) * line_length +
275 					       j / 8];
276 				u8 bit = (byte >> (j % 8)) & 1;
277 				data |= bit << k;
278 			}
279 			array->data[array_idx++] = data;
280 		}
281 	}
282 
283 	ret = ssd1307fb_write_array(par->client, array, width * pages);
284 
285 out_free:
286 	kfree(array);
287 	return ret;
288 }
289 
ssd1307fb_update_display(struct ssd1307fb_par * par)290 static int ssd1307fb_update_display(struct ssd1307fb_par *par)
291 {
292 	return ssd1307fb_update_rect(par, 0, 0, par->width, par->height);
293 }
294 
ssd1307fb_blank(int blank_mode,struct fb_info * info)295 static int ssd1307fb_blank(int blank_mode, struct fb_info *info)
296 {
297 	struct ssd1307fb_par *par = info->par;
298 
299 	if (blank_mode != FB_BLANK_UNBLANK)
300 		return ssd1307fb_write_cmd(par->client, SSD1307FB_DISPLAY_OFF);
301 	else
302 		return ssd1307fb_write_cmd(par->client, SSD1307FB_DISPLAY_ON);
303 }
304 
ssd1307fb_defio_damage_range(struct fb_info * info,off_t off,size_t len)305 static void ssd1307fb_defio_damage_range(struct fb_info *info, off_t off, size_t len)
306 {
307 	struct ssd1307fb_par *par = info->par;
308 
309 	ssd1307fb_update_display(par);
310 }
311 
ssd1307fb_defio_damage_area(struct fb_info * info,u32 x,u32 y,u32 width,u32 height)312 static void ssd1307fb_defio_damage_area(struct fb_info *info, u32 x, u32 y,
313 					u32 width, u32 height)
314 {
315 	struct ssd1307fb_par *par = info->par;
316 
317 	ssd1307fb_update_rect(par, x, y, width, height);
318 }
319 
320 FB_GEN_DEFAULT_DEFERRED_SYSMEM_OPS(ssd1307fb,
321 				   ssd1307fb_defio_damage_range,
322 				   ssd1307fb_defio_damage_area)
323 
324 static const struct fb_ops ssd1307fb_ops = {
325 	.owner		= THIS_MODULE,
326 	FB_DEFAULT_DEFERRED_OPS(ssd1307fb),
327 	.fb_blank	= ssd1307fb_blank,
328 };
329 
ssd1307fb_deferred_io(struct fb_info * info,struct list_head * pagereflist)330 static void ssd1307fb_deferred_io(struct fb_info *info, struct list_head *pagereflist)
331 {
332 	ssd1307fb_update_display(info->par);
333 }
334 
ssd1307fb_init(struct ssd1307fb_par * par)335 static int ssd1307fb_init(struct ssd1307fb_par *par)
336 {
337 	struct pwm_state pwmstate;
338 	int ret;
339 	u32 precharge, dclk, com_invdir, compins;
340 
341 	if (par->device_info->need_pwm) {
342 		par->pwm = pwm_get(&par->client->dev, NULL);
343 		if (IS_ERR(par->pwm)) {
344 			dev_err(&par->client->dev, "Could not get PWM from device tree!\n");
345 			return PTR_ERR(par->pwm);
346 		}
347 
348 		pwm_init_state(par->pwm, &pwmstate);
349 		pwm_set_relative_duty_cycle(&pwmstate, 50, 100);
350 		pwm_apply_might_sleep(par->pwm, &pwmstate);
351 
352 		/* Enable the PWM */
353 		pwm_enable(par->pwm);
354 
355 		dev_dbg(&par->client->dev, "Using PWM %s with a %lluns period.\n",
356 			par->pwm->label, pwm_get_period(par->pwm));
357 	}
358 
359 	/* Set initial contrast */
360 	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_CONTRAST);
361 	if (ret < 0)
362 		return ret;
363 
364 	ret = ssd1307fb_write_cmd(par->client, par->contrast);
365 	if (ret < 0)
366 		return ret;
367 
368 	/* Set segment re-map */
369 	if (par->seg_remap) {
370 		ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SEG_REMAP_ON);
371 		if (ret < 0)
372 			return ret;
373 	}
374 
375 	/* Set COM direction */
376 	com_invdir = 0xc0 | par->com_invdir << 3;
377 	ret = ssd1307fb_write_cmd(par->client,  com_invdir);
378 	if (ret < 0)
379 		return ret;
380 
381 	/* Set multiplex ratio value */
382 	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_MULTIPLEX_RATIO);
383 	if (ret < 0)
384 		return ret;
385 
386 	ret = ssd1307fb_write_cmd(par->client, par->height - 1);
387 	if (ret < 0)
388 		return ret;
389 
390 	/* set display offset value */
391 	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_DISPLAY_OFFSET);
392 	if (ret < 0)
393 		return ret;
394 
395 	ret = ssd1307fb_write_cmd(par->client, par->com_offset);
396 	if (ret < 0)
397 		return ret;
398 
399 	/* Set clock frequency */
400 	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_CLOCK_FREQ);
401 	if (ret < 0)
402 		return ret;
403 
404 	dclk = ((par->dclk_div - 1) & 0xf) | (par->dclk_frq & 0xf) << 4;
405 	ret = ssd1307fb_write_cmd(par->client, dclk);
406 	if (ret < 0)
407 		return ret;
408 
409 	/* Set Area Color Mode ON/OFF & Low Power Display Mode */
410 	if (par->area_color_enable || par->low_power) {
411 		u32 mode;
412 
413 		ret = ssd1307fb_write_cmd(par->client,
414 					  SSD1307FB_SET_AREA_COLOR_MODE);
415 		if (ret < 0)
416 			return ret;
417 
418 		mode = (par->area_color_enable ? 0x30 : 0) |
419 			(par->low_power ? 5 : 0);
420 		ret = ssd1307fb_write_cmd(par->client, mode);
421 		if (ret < 0)
422 			return ret;
423 	}
424 
425 	/* Set precharge period in number of ticks from the internal clock */
426 	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_PRECHARGE_PERIOD);
427 	if (ret < 0)
428 		return ret;
429 
430 	precharge = (par->prechargep1 & 0xf) | (par->prechargep2 & 0xf) << 4;
431 	ret = ssd1307fb_write_cmd(par->client, precharge);
432 	if (ret < 0)
433 		return ret;
434 
435 	/* Set COM pins configuration */
436 	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_COM_PINS_CONFIG);
437 	if (ret < 0)
438 		return ret;
439 
440 	compins = 0x02 | !par->com_seq << 4 | par->com_lrremap << 5;
441 	ret = ssd1307fb_write_cmd(par->client, compins);
442 	if (ret < 0)
443 		return ret;
444 
445 	/* Set VCOMH */
446 	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_VCOMH);
447 	if (ret < 0)
448 		return ret;
449 
450 	ret = ssd1307fb_write_cmd(par->client, par->vcomh);
451 	if (ret < 0)
452 		return ret;
453 
454 	/* Turn on the DC-DC Charge Pump */
455 	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_CHARGE_PUMP);
456 	if (ret < 0)
457 		return ret;
458 
459 	ret = ssd1307fb_write_cmd(par->client,
460 		BIT(4) | (par->device_info->need_chargepump ? BIT(2) : 0));
461 	if (ret < 0)
462 		return ret;
463 
464 	/* Set lookup table */
465 	if (par->lookup_table_set) {
466 		int i;
467 
468 		ret = ssd1307fb_write_cmd(par->client,
469 					  SSD1307FB_SET_LOOKUP_TABLE);
470 		if (ret < 0)
471 			return ret;
472 
473 		for (i = 0; i < ARRAY_SIZE(par->lookup_table); ++i) {
474 			u8 val = par->lookup_table[i];
475 
476 			if (val < 31 || val > 63)
477 				dev_warn(&par->client->dev,
478 					 "lookup table index %d value out of range 31 <= %d <= 63\n",
479 					 i, val);
480 			ret = ssd1307fb_write_cmd(par->client, val);
481 			if (ret < 0)
482 				return ret;
483 		}
484 	}
485 
486 	/* Switch to horizontal addressing mode */
487 	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_ADDRESS_MODE);
488 	if (ret < 0)
489 		return ret;
490 
491 	ret = ssd1307fb_write_cmd(par->client,
492 				  SSD1307FB_SET_ADDRESS_MODE_HORIZONTAL);
493 	if (ret < 0)
494 		return ret;
495 
496 	/* Clear the screen */
497 	ret = ssd1307fb_update_display(par);
498 	if (ret < 0)
499 		return ret;
500 
501 	/* Turn on the display */
502 	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_DISPLAY_ON);
503 	if (ret < 0)
504 		return ret;
505 
506 	return 0;
507 }
508 
ssd1307fb_update_bl(struct backlight_device * bdev)509 static int ssd1307fb_update_bl(struct backlight_device *bdev)
510 {
511 	struct ssd1307fb_par *par = bl_get_data(bdev);
512 	int ret;
513 	int brightness = bdev->props.brightness;
514 
515 	par->contrast = brightness;
516 
517 	ret = ssd1307fb_write_cmd(par->client, SSD1307FB_CONTRAST);
518 	if (ret < 0)
519 		return ret;
520 	ret = ssd1307fb_write_cmd(par->client, par->contrast);
521 	if (ret < 0)
522 		return ret;
523 	return 0;
524 }
525 
ssd1307fb_get_brightness(struct backlight_device * bdev)526 static int ssd1307fb_get_brightness(struct backlight_device *bdev)
527 {
528 	struct ssd1307fb_par *par = bl_get_data(bdev);
529 
530 	return par->contrast;
531 }
532 
ssd1307fb_check_fb(struct backlight_device * bdev,struct fb_info * info)533 static int ssd1307fb_check_fb(struct backlight_device *bdev,
534 				   struct fb_info *info)
535 {
536 	return (info->bl_dev == bdev);
537 }
538 
539 static const struct backlight_ops ssd1307fb_bl_ops = {
540 	.options	= BL_CORE_SUSPENDRESUME,
541 	.update_status	= ssd1307fb_update_bl,
542 	.get_brightness	= ssd1307fb_get_brightness,
543 	.check_fb	= ssd1307fb_check_fb,
544 };
545 
546 static struct ssd1307fb_deviceinfo ssd1307fb_ssd1305_deviceinfo = {
547 	.default_vcomh = 0x34,
548 	.default_dclk_div = 1,
549 	.default_dclk_frq = 7,
550 };
551 
552 static struct ssd1307fb_deviceinfo ssd1307fb_ssd1306_deviceinfo = {
553 	.default_vcomh = 0x20,
554 	.default_dclk_div = 1,
555 	.default_dclk_frq = 8,
556 	.need_chargepump = 1,
557 };
558 
559 static struct ssd1307fb_deviceinfo ssd1307fb_ssd1307_deviceinfo = {
560 	.default_vcomh = 0x20,
561 	.default_dclk_div = 2,
562 	.default_dclk_frq = 12,
563 	.need_pwm = 1,
564 };
565 
566 static struct ssd1307fb_deviceinfo ssd1307fb_ssd1309_deviceinfo = {
567 	.default_vcomh = 0x34,
568 	.default_dclk_div = 1,
569 	.default_dclk_frq = 10,
570 };
571 
572 static const struct of_device_id ssd1307fb_of_match[] = {
573 	{
574 		.compatible = "solomon,ssd1305fb-i2c",
575 		.data = (void *)&ssd1307fb_ssd1305_deviceinfo,
576 	},
577 	{
578 		.compatible = "solomon,ssd1306fb-i2c",
579 		.data = (void *)&ssd1307fb_ssd1306_deviceinfo,
580 	},
581 	{
582 		.compatible = "solomon,ssd1307fb-i2c",
583 		.data = (void *)&ssd1307fb_ssd1307_deviceinfo,
584 	},
585 	{
586 		.compatible = "solomon,ssd1309fb-i2c",
587 		.data = (void *)&ssd1307fb_ssd1309_deviceinfo,
588 	},
589 	{},
590 };
591 MODULE_DEVICE_TABLE(of, ssd1307fb_of_match);
592 
ssd1307fb_probe(struct i2c_client * client)593 static int ssd1307fb_probe(struct i2c_client *client)
594 {
595 	struct device *dev = &client->dev;
596 	struct backlight_device *bl;
597 	char bl_name[12];
598 	struct fb_info *info;
599 	struct fb_deferred_io *ssd1307fb_defio;
600 	u32 vmem_size;
601 	struct ssd1307fb_par *par;
602 	void *vmem;
603 	int ret;
604 
605 	info = framebuffer_alloc(sizeof(struct ssd1307fb_par), dev);
606 	if (!info)
607 		return -ENOMEM;
608 
609 	par = info->par;
610 	par->info = info;
611 	par->client = client;
612 
613 	par->device_info = device_get_match_data(dev);
614 
615 	par->reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
616 	if (IS_ERR(par->reset)) {
617 		ret = dev_err_probe(dev, PTR_ERR(par->reset),
618 				    "failed to get reset gpio\n");
619 		goto fb_alloc_error;
620 	}
621 
622 	par->vbat_reg = devm_regulator_get_optional(dev, "vbat");
623 	if (IS_ERR(par->vbat_reg)) {
624 		ret = PTR_ERR(par->vbat_reg);
625 		if (ret == -ENODEV) {
626 			par->vbat_reg = NULL;
627 		} else {
628 			dev_err_probe(dev, ret, "failed to get VBAT regulator\n");
629 			goto fb_alloc_error;
630 		}
631 	}
632 
633 	if (device_property_read_u32(dev, "solomon,width", &par->width))
634 		par->width = 96;
635 
636 	if (device_property_read_u32(dev, "solomon,height", &par->height))
637 		par->height = 16;
638 
639 	if (device_property_read_u32(dev, "solomon,page-offset", &par->page_offset))
640 		par->page_offset = 1;
641 
642 	if (device_property_read_u32(dev, "solomon,col-offset", &par->col_offset))
643 		par->col_offset = 0;
644 
645 	if (device_property_read_u32(dev, "solomon,com-offset", &par->com_offset))
646 		par->com_offset = 0;
647 
648 	if (device_property_read_u32(dev, "solomon,prechargep1", &par->prechargep1))
649 		par->prechargep1 = 2;
650 
651 	if (device_property_read_u32(dev, "solomon,prechargep2", &par->prechargep2))
652 		par->prechargep2 = 2;
653 
654 	if (!device_property_read_u8_array(dev, "solomon,lookup-table",
655 					   par->lookup_table,
656 					   ARRAY_SIZE(par->lookup_table)))
657 		par->lookup_table_set = 1;
658 
659 	par->seg_remap = !device_property_read_bool(dev, "solomon,segment-no-remap");
660 	par->com_seq = device_property_read_bool(dev, "solomon,com-seq");
661 	par->com_lrremap = device_property_read_bool(dev, "solomon,com-lrremap");
662 	par->com_invdir = device_property_read_bool(dev, "solomon,com-invdir");
663 	par->area_color_enable =
664 		device_property_read_bool(dev, "solomon,area-color-enable");
665 	par->low_power = device_property_read_bool(dev, "solomon,low-power");
666 
667 	par->contrast = 127;
668 	par->vcomh = par->device_info->default_vcomh;
669 
670 	/* Setup display timing */
671 	if (device_property_read_u32(dev, "solomon,dclk-div", &par->dclk_div))
672 		par->dclk_div = par->device_info->default_dclk_div;
673 	if (device_property_read_u32(dev, "solomon,dclk-frq", &par->dclk_frq))
674 		par->dclk_frq = par->device_info->default_dclk_frq;
675 
676 	vmem_size = DIV_ROUND_UP(par->width, 8) * par->height;
677 
678 	vmem = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
679 					get_order(vmem_size));
680 	if (!vmem) {
681 		dev_err(dev, "Couldn't allocate graphical memory.\n");
682 		ret = -ENOMEM;
683 		goto fb_alloc_error;
684 	}
685 
686 	ssd1307fb_defio = devm_kzalloc(dev, sizeof(*ssd1307fb_defio),
687 				       GFP_KERNEL);
688 	if (!ssd1307fb_defio) {
689 		dev_err(dev, "Couldn't allocate deferred io.\n");
690 		ret = -ENOMEM;
691 		goto fb_alloc_error;
692 	}
693 
694 	ssd1307fb_defio->delay = HZ / refreshrate;
695 	ssd1307fb_defio->deferred_io = ssd1307fb_deferred_io;
696 
697 	info->fbops = &ssd1307fb_ops;
698 	info->fix = ssd1307fb_fix;
699 	info->fix.line_length = DIV_ROUND_UP(par->width, 8);
700 	info->fbdefio = ssd1307fb_defio;
701 
702 	info->var = ssd1307fb_var;
703 	info->var.xres = par->width;
704 	info->var.xres_virtual = par->width;
705 	info->var.yres = par->height;
706 	info->var.yres_virtual = par->height;
707 
708 	info->screen_buffer = vmem;
709 	info->fix.smem_start = __pa(vmem);
710 	info->fix.smem_len = vmem_size;
711 
712 	fb_deferred_io_init(info);
713 
714 	i2c_set_clientdata(client, info);
715 
716 	if (par->reset) {
717 		/* Reset the screen */
718 		gpiod_set_value_cansleep(par->reset, 1);
719 		udelay(4);
720 		gpiod_set_value_cansleep(par->reset, 0);
721 		udelay(4);
722 	}
723 
724 	if (par->vbat_reg) {
725 		ret = regulator_enable(par->vbat_reg);
726 		if (ret) {
727 			dev_err(dev, "failed to enable VBAT: %d\n", ret);
728 			goto reset_oled_error;
729 		}
730 	}
731 
732 	ret = ssd1307fb_init(par);
733 	if (ret)
734 		goto regulator_enable_error;
735 
736 	ret = register_framebuffer(info);
737 	if (ret) {
738 		dev_err(dev, "Couldn't register the framebuffer\n");
739 		goto panel_init_error;
740 	}
741 
742 	snprintf(bl_name, sizeof(bl_name), "ssd1307fb%d", info->node);
743 	bl = backlight_device_register(bl_name, dev, par, &ssd1307fb_bl_ops,
744 				       NULL);
745 	if (IS_ERR(bl)) {
746 		ret = PTR_ERR(bl);
747 		dev_err(dev, "unable to register backlight device: %d\n", ret);
748 		goto bl_init_error;
749 	}
750 
751 	bl->props.brightness = par->contrast;
752 	bl->props.max_brightness = MAX_CONTRAST;
753 	info->bl_dev = bl;
754 
755 	dev_info(dev, "fb%d: %s framebuffer device registered, using %d bytes of video memory\n", info->node, info->fix.id, vmem_size);
756 
757 	return 0;
758 
759 bl_init_error:
760 	unregister_framebuffer(info);
761 panel_init_error:
762 	pwm_disable(par->pwm);
763 	pwm_put(par->pwm);
764 regulator_enable_error:
765 	if (par->vbat_reg)
766 		regulator_disable(par->vbat_reg);
767 reset_oled_error:
768 	fb_deferred_io_cleanup(info);
769 fb_alloc_error:
770 	framebuffer_release(info);
771 	return ret;
772 }
773 
ssd1307fb_remove(struct i2c_client * client)774 static void ssd1307fb_remove(struct i2c_client *client)
775 {
776 	struct fb_info *info = i2c_get_clientdata(client);
777 	struct ssd1307fb_par *par = info->par;
778 
779 	ssd1307fb_write_cmd(par->client, SSD1307FB_DISPLAY_OFF);
780 
781 	backlight_device_unregister(info->bl_dev);
782 
783 	unregister_framebuffer(info);
784 	pwm_disable(par->pwm);
785 	pwm_put(par->pwm);
786 	if (par->vbat_reg)
787 		regulator_disable(par->vbat_reg);
788 	fb_deferred_io_cleanup(info);
789 	__free_pages(__va(info->fix.smem_start), get_order(info->fix.smem_len));
790 	framebuffer_release(info);
791 }
792 
793 static const struct i2c_device_id ssd1307fb_i2c_id[] = {
794 	{ "ssd1305fb", 0 },
795 	{ "ssd1306fb", 0 },
796 	{ "ssd1307fb", 0 },
797 	{ "ssd1309fb", 0 },
798 	{ }
799 };
800 MODULE_DEVICE_TABLE(i2c, ssd1307fb_i2c_id);
801 
802 static struct i2c_driver ssd1307fb_driver = {
803 	.probe = ssd1307fb_probe,
804 	.remove = ssd1307fb_remove,
805 	.id_table = ssd1307fb_i2c_id,
806 	.driver = {
807 		.name = "ssd1307fb",
808 		.of_match_table = ssd1307fb_of_match,
809 	},
810 };
811 
812 module_i2c_driver(ssd1307fb_driver);
813 
814 MODULE_DESCRIPTION("FB driver for the Solomon SSD1307 OLED controller");
815 MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
816 MODULE_LICENSE("GPL");
817