xref: /linux/drivers/gpu/drm/solomon/ssd130x.c (revision 0e9ab8e4d44ae9d9aaf213bfd2c90bbe7289337b)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * DRM driver for Solomon SSD130x OLED displays
4  *
5  * Copyright 2022 Red Hat Inc.
6  * Author: Javier Martinez Canillas <javierm@redhat.com>
7  *
8  * Based on drivers/video/fbdev/ssd1307fb.c
9  * Copyright 2012 Free Electrons
10  */
11 
12 #include <linux/backlight.h>
13 #include <linux/bitfield.h>
14 #include <linux/bits.h>
15 #include <linux/delay.h>
16 #include <linux/gpio/consumer.h>
17 #include <linux/property.h>
18 #include <linux/pwm.h>
19 #include <linux/regulator/consumer.h>
20 
21 #include <drm/drm_atomic.h>
22 #include <drm/drm_atomic_helper.h>
23 #include <drm/drm_crtc_helper.h>
24 #include <drm/drm_damage_helper.h>
25 #include <drm/drm_edid.h>
26 #include <drm/drm_fbdev_generic.h>
27 #include <drm/drm_format_helper.h>
28 #include <drm/drm_framebuffer.h>
29 #include <drm/drm_gem_atomic_helper.h>
30 #include <drm/drm_gem_framebuffer_helper.h>
31 #include <drm/drm_gem_shmem_helper.h>
32 #include <drm/drm_managed.h>
33 #include <drm/drm_modes.h>
34 #include <drm/drm_rect.h>
35 #include <drm/drm_probe_helper.h>
36 
37 #include "ssd130x.h"
38 
39 #define DRIVER_NAME	"ssd130x"
40 #define DRIVER_DESC	"DRM driver for Solomon SSD130x OLED displays"
41 #define DRIVER_DATE	"20220131"
42 #define DRIVER_MAJOR	1
43 #define DRIVER_MINOR	0
44 
45 #define SSD130X_PAGE_COL_START_LOW		0x00
46 #define SSD130X_PAGE_COL_START_HIGH		0x10
47 #define SSD130X_SET_ADDRESS_MODE		0x20
48 #define SSD130X_SET_COL_RANGE			0x21
49 #define SSD130X_SET_PAGE_RANGE			0x22
50 #define SSD130X_CONTRAST			0x81
51 #define SSD130X_SET_LOOKUP_TABLE		0x91
52 #define SSD130X_CHARGE_PUMP			0x8d
53 #define SSD130X_SET_SEG_REMAP			0xa0
54 #define SSD130X_DISPLAY_OFF			0xae
55 #define SSD130X_SET_MULTIPLEX_RATIO		0xa8
56 #define SSD130X_DISPLAY_ON			0xaf
57 #define SSD130X_START_PAGE_ADDRESS		0xb0
58 #define SSD130X_SET_COM_SCAN_DIR		0xc0
59 #define SSD130X_SET_DISPLAY_OFFSET		0xd3
60 #define SSD130X_SET_CLOCK_FREQ			0xd5
61 #define SSD130X_SET_AREA_COLOR_MODE		0xd8
62 #define SSD130X_SET_PRECHARGE_PERIOD		0xd9
63 #define SSD130X_SET_COM_PINS_CONFIG		0xda
64 #define SSD130X_SET_VCOMH			0xdb
65 
66 #define SSD130X_PAGE_COL_START_MASK		GENMASK(3, 0)
67 #define SSD130X_PAGE_COL_START_HIGH_SET(val)	FIELD_PREP(SSD130X_PAGE_COL_START_MASK, (val) >> 4)
68 #define SSD130X_PAGE_COL_START_LOW_SET(val)	FIELD_PREP(SSD130X_PAGE_COL_START_MASK, (val))
69 #define SSD130X_START_PAGE_ADDRESS_MASK		GENMASK(2, 0)
70 #define SSD130X_START_PAGE_ADDRESS_SET(val)	FIELD_PREP(SSD130X_START_PAGE_ADDRESS_MASK, (val))
71 #define SSD130X_SET_SEG_REMAP_MASK		GENMASK(0, 0)
72 #define SSD130X_SET_SEG_REMAP_SET(val)		FIELD_PREP(SSD130X_SET_SEG_REMAP_MASK, (val))
73 #define SSD130X_SET_COM_SCAN_DIR_MASK		GENMASK(3, 3)
74 #define SSD130X_SET_COM_SCAN_DIR_SET(val)	FIELD_PREP(SSD130X_SET_COM_SCAN_DIR_MASK, (val))
75 #define SSD130X_SET_CLOCK_DIV_MASK		GENMASK(3, 0)
76 #define SSD130X_SET_CLOCK_DIV_SET(val)		FIELD_PREP(SSD130X_SET_CLOCK_DIV_MASK, (val))
77 #define SSD130X_SET_CLOCK_FREQ_MASK		GENMASK(7, 4)
78 #define SSD130X_SET_CLOCK_FREQ_SET(val)		FIELD_PREP(SSD130X_SET_CLOCK_FREQ_MASK, (val))
79 #define SSD130X_SET_PRECHARGE_PERIOD1_MASK	GENMASK(3, 0)
80 #define SSD130X_SET_PRECHARGE_PERIOD1_SET(val)	FIELD_PREP(SSD130X_SET_PRECHARGE_PERIOD1_MASK, (val))
81 #define SSD130X_SET_PRECHARGE_PERIOD2_MASK	GENMASK(7, 4)
82 #define SSD130X_SET_PRECHARGE_PERIOD2_SET(val)	FIELD_PREP(SSD130X_SET_PRECHARGE_PERIOD2_MASK, (val))
83 #define SSD130X_SET_COM_PINS_CONFIG1_MASK	GENMASK(4, 4)
84 #define SSD130X_SET_COM_PINS_CONFIG1_SET(val)	FIELD_PREP(SSD130X_SET_COM_PINS_CONFIG1_MASK, (val))
85 #define SSD130X_SET_COM_PINS_CONFIG2_MASK	GENMASK(5, 5)
86 #define SSD130X_SET_COM_PINS_CONFIG2_SET(val)	FIELD_PREP(SSD130X_SET_COM_PINS_CONFIG2_MASK, (val))
87 
88 #define SSD130X_SET_ADDRESS_MODE_HORIZONTAL	0x00
89 #define SSD130X_SET_ADDRESS_MODE_VERTICAL	0x01
90 #define SSD130X_SET_ADDRESS_MODE_PAGE		0x02
91 
92 #define SSD130X_SET_AREA_COLOR_MODE_ENABLE	0x1e
93 #define SSD130X_SET_AREA_COLOR_MODE_LOW_POWER	0x05
94 
95 #define MAX_CONTRAST 255
96 
97 const struct ssd130x_deviceinfo ssd130x_variants[] = {
98 	[SH1106_ID] = {
99 		.default_vcomh = 0x40,
100 		.default_dclk_div = 1,
101 		.default_dclk_frq = 5,
102 		.page_mode_only = 1,
103 	},
104 	[SSD1305_ID] = {
105 		.default_vcomh = 0x34,
106 		.default_dclk_div = 1,
107 		.default_dclk_frq = 7,
108 	},
109 	[SSD1306_ID] = {
110 		.default_vcomh = 0x20,
111 		.default_dclk_div = 1,
112 		.default_dclk_frq = 8,
113 		.need_chargepump = 1,
114 	},
115 	[SSD1307_ID] = {
116 		.default_vcomh = 0x20,
117 		.default_dclk_div = 2,
118 		.default_dclk_frq = 12,
119 		.need_pwm = 1,
120 	},
121 	[SSD1309_ID] = {
122 		.default_vcomh = 0x34,
123 		.default_dclk_div = 1,
124 		.default_dclk_frq = 10,
125 	}
126 };
127 EXPORT_SYMBOL_NS_GPL(ssd130x_variants, DRM_SSD130X);
128 
129 static inline struct ssd130x_device *drm_to_ssd130x(struct drm_device *drm)
130 {
131 	return container_of(drm, struct ssd130x_device, drm);
132 }
133 
134 /*
135  * Helper to write data (SSD130X_DATA) to the device.
136  */
137 static int ssd130x_write_data(struct ssd130x_device *ssd130x, u8 *values, int count)
138 {
139 	return regmap_bulk_write(ssd130x->regmap, SSD130X_DATA, values, count);
140 }
141 
142 /*
143  * Helper to write command (SSD130X_COMMAND). The fist variadic argument
144  * is the command to write and the following are the command options.
145  *
146  * Note that the ssd130x protocol requires each command and option to be
147  * written as a SSD130X_COMMAND device register value. That is why a call
148  * to regmap_write(..., SSD130X_COMMAND, ...) is done for each argument.
149  */
150 static int ssd130x_write_cmd(struct ssd130x_device *ssd130x, int count,
151 			     /* u8 cmd, u8 option, ... */...)
152 {
153 	va_list ap;
154 	u8 value;
155 	int ret;
156 
157 	va_start(ap, count);
158 
159 	do {
160 		value = va_arg(ap, int);
161 		ret = regmap_write(ssd130x->regmap, SSD130X_COMMAND, value);
162 		if (ret)
163 			goto out_end;
164 	} while (--count);
165 
166 out_end:
167 	va_end(ap);
168 
169 	return ret;
170 }
171 
172 /* Set address range for horizontal/vertical addressing modes */
173 static int ssd130x_set_col_range(struct ssd130x_device *ssd130x,
174 				 u8 col_start, u8 cols)
175 {
176 	u8 col_end = col_start + cols - 1;
177 	int ret;
178 
179 	if (col_start == ssd130x->col_start && col_end == ssd130x->col_end)
180 		return 0;
181 
182 	ret = ssd130x_write_cmd(ssd130x, 3, SSD130X_SET_COL_RANGE, col_start, col_end);
183 	if (ret < 0)
184 		return ret;
185 
186 	ssd130x->col_start = col_start;
187 	ssd130x->col_end = col_end;
188 	return 0;
189 }
190 
191 static int ssd130x_set_page_range(struct ssd130x_device *ssd130x,
192 				  u8 page_start, u8 pages)
193 {
194 	u8 page_end = page_start + pages - 1;
195 	int ret;
196 
197 	if (page_start == ssd130x->page_start && page_end == ssd130x->page_end)
198 		return 0;
199 
200 	ret = ssd130x_write_cmd(ssd130x, 3, SSD130X_SET_PAGE_RANGE, page_start, page_end);
201 	if (ret < 0)
202 		return ret;
203 
204 	ssd130x->page_start = page_start;
205 	ssd130x->page_end = page_end;
206 	return 0;
207 }
208 
209 /* Set page and column start address for page addressing mode */
210 static int ssd130x_set_page_pos(struct ssd130x_device *ssd130x,
211 				u8 page_start, u8 col_start)
212 {
213 	int ret;
214 	u32 page, col_low, col_high;
215 
216 	page = SSD130X_START_PAGE_ADDRESS |
217 	       SSD130X_START_PAGE_ADDRESS_SET(page_start);
218 	col_low = SSD130X_PAGE_COL_START_LOW |
219 		  SSD130X_PAGE_COL_START_LOW_SET(col_start);
220 	col_high = SSD130X_PAGE_COL_START_HIGH |
221 		   SSD130X_PAGE_COL_START_HIGH_SET(col_start);
222 	ret = ssd130x_write_cmd(ssd130x, 3, page, col_low, col_high);
223 	if (ret < 0)
224 		return ret;
225 
226 	return 0;
227 }
228 
229 static int ssd130x_pwm_enable(struct ssd130x_device *ssd130x)
230 {
231 	struct device *dev = ssd130x->dev;
232 	struct pwm_state pwmstate;
233 
234 	ssd130x->pwm = pwm_get(dev, NULL);
235 	if (IS_ERR(ssd130x->pwm)) {
236 		dev_err(dev, "Could not get PWM from firmware description!\n");
237 		return PTR_ERR(ssd130x->pwm);
238 	}
239 
240 	pwm_init_state(ssd130x->pwm, &pwmstate);
241 	pwm_set_relative_duty_cycle(&pwmstate, 50, 100);
242 	pwm_apply_state(ssd130x->pwm, &pwmstate);
243 
244 	/* Enable the PWM */
245 	pwm_enable(ssd130x->pwm);
246 
247 	dev_dbg(dev, "Using PWM%d with a %lluns period.\n",
248 		ssd130x->pwm->pwm, pwm_get_period(ssd130x->pwm));
249 
250 	return 0;
251 }
252 
253 static void ssd130x_reset(struct ssd130x_device *ssd130x)
254 {
255 	if (!ssd130x->reset)
256 		return;
257 
258 	/* Reset the screen */
259 	gpiod_set_value_cansleep(ssd130x->reset, 1);
260 	udelay(4);
261 	gpiod_set_value_cansleep(ssd130x->reset, 0);
262 	udelay(4);
263 }
264 
265 static int ssd130x_power_on(struct ssd130x_device *ssd130x)
266 {
267 	struct device *dev = ssd130x->dev;
268 	int ret;
269 
270 	ssd130x_reset(ssd130x);
271 
272 	ret = regulator_enable(ssd130x->vcc_reg);
273 	if (ret) {
274 		dev_err(dev, "Failed to enable VCC: %d\n", ret);
275 		return ret;
276 	}
277 
278 	if (ssd130x->device_info->need_pwm) {
279 		ret = ssd130x_pwm_enable(ssd130x);
280 		if (ret) {
281 			dev_err(dev, "Failed to enable PWM: %d\n", ret);
282 			regulator_disable(ssd130x->vcc_reg);
283 			return ret;
284 		}
285 	}
286 
287 	return 0;
288 }
289 
290 static void ssd130x_power_off(struct ssd130x_device *ssd130x)
291 {
292 	pwm_disable(ssd130x->pwm);
293 	pwm_put(ssd130x->pwm);
294 
295 	regulator_disable(ssd130x->vcc_reg);
296 }
297 
298 static int ssd130x_init(struct ssd130x_device *ssd130x)
299 {
300 	u32 precharge, dclk, com_invdir, compins, chargepump, seg_remap;
301 	bool scan_mode;
302 	int ret;
303 
304 	/* Set initial contrast */
305 	ret = ssd130x_write_cmd(ssd130x, 2, SSD130X_CONTRAST, ssd130x->contrast);
306 	if (ret < 0)
307 		return ret;
308 
309 	/* Set segment re-map */
310 	seg_remap = (SSD130X_SET_SEG_REMAP |
311 		     SSD130X_SET_SEG_REMAP_SET(ssd130x->seg_remap));
312 	ret = ssd130x_write_cmd(ssd130x, 1, seg_remap);
313 	if (ret < 0)
314 		return ret;
315 
316 	/* Set COM direction */
317 	com_invdir = (SSD130X_SET_COM_SCAN_DIR |
318 		      SSD130X_SET_COM_SCAN_DIR_SET(ssd130x->com_invdir));
319 	ret = ssd130x_write_cmd(ssd130x,  1, com_invdir);
320 	if (ret < 0)
321 		return ret;
322 
323 	/* Set multiplex ratio value */
324 	ret = ssd130x_write_cmd(ssd130x, 2, SSD130X_SET_MULTIPLEX_RATIO, ssd130x->height - 1);
325 	if (ret < 0)
326 		return ret;
327 
328 	/* set display offset value */
329 	ret = ssd130x_write_cmd(ssd130x, 2, SSD130X_SET_DISPLAY_OFFSET, ssd130x->com_offset);
330 	if (ret < 0)
331 		return ret;
332 
333 	/* Set clock frequency */
334 	dclk = (SSD130X_SET_CLOCK_DIV_SET(ssd130x->dclk_div - 1) |
335 		SSD130X_SET_CLOCK_FREQ_SET(ssd130x->dclk_frq));
336 	ret = ssd130x_write_cmd(ssd130x, 2, SSD130X_SET_CLOCK_FREQ, dclk);
337 	if (ret < 0)
338 		return ret;
339 
340 	/* Set Area Color Mode ON/OFF & Low Power Display Mode */
341 	if (ssd130x->area_color_enable || ssd130x->low_power) {
342 		u32 mode = 0;
343 
344 		if (ssd130x->area_color_enable)
345 			mode |= SSD130X_SET_AREA_COLOR_MODE_ENABLE;
346 
347 		if (ssd130x->low_power)
348 			mode |= SSD130X_SET_AREA_COLOR_MODE_LOW_POWER;
349 
350 		ret = ssd130x_write_cmd(ssd130x, 2, SSD130X_SET_AREA_COLOR_MODE, mode);
351 		if (ret < 0)
352 			return ret;
353 	}
354 
355 	/* Set precharge period in number of ticks from the internal clock */
356 	precharge = (SSD130X_SET_PRECHARGE_PERIOD1_SET(ssd130x->prechargep1) |
357 		     SSD130X_SET_PRECHARGE_PERIOD2_SET(ssd130x->prechargep2));
358 	ret = ssd130x_write_cmd(ssd130x, 2, SSD130X_SET_PRECHARGE_PERIOD, precharge);
359 	if (ret < 0)
360 		return ret;
361 
362 	/* Set COM pins configuration */
363 	compins = BIT(1);
364 	/*
365 	 * The COM scan mode field values are the inverse of the boolean DT
366 	 * property "solomon,com-seq". The value 0b means scan from COM0 to
367 	 * COM[N - 1] while 1b means scan from COM[N - 1] to COM0.
368 	 */
369 	scan_mode = !ssd130x->com_seq;
370 	compins |= (SSD130X_SET_COM_PINS_CONFIG1_SET(scan_mode) |
371 		    SSD130X_SET_COM_PINS_CONFIG2_SET(ssd130x->com_lrremap));
372 	ret = ssd130x_write_cmd(ssd130x, 2, SSD130X_SET_COM_PINS_CONFIG, compins);
373 	if (ret < 0)
374 		return ret;
375 
376 	/* Set VCOMH */
377 	ret = ssd130x_write_cmd(ssd130x, 2, SSD130X_SET_VCOMH, ssd130x->vcomh);
378 	if (ret < 0)
379 		return ret;
380 
381 	/* Turn on the DC-DC Charge Pump */
382 	chargepump = BIT(4);
383 
384 	if (ssd130x->device_info->need_chargepump)
385 		chargepump |= BIT(2);
386 
387 	ret = ssd130x_write_cmd(ssd130x, 2, SSD130X_CHARGE_PUMP, chargepump);
388 	if (ret < 0)
389 		return ret;
390 
391 	/* Set lookup table */
392 	if (ssd130x->lookup_table_set) {
393 		int i;
394 
395 		ret = ssd130x_write_cmd(ssd130x, 1, SSD130X_SET_LOOKUP_TABLE);
396 		if (ret < 0)
397 			return ret;
398 
399 		for (i = 0; i < ARRAY_SIZE(ssd130x->lookup_table); i++) {
400 			u8 val = ssd130x->lookup_table[i];
401 
402 			if (val < 31 || val > 63)
403 				dev_warn(ssd130x->dev,
404 					 "lookup table index %d value out of range 31 <= %d <= 63\n",
405 					 i, val);
406 			ret = ssd130x_write_cmd(ssd130x, 1, val);
407 			if (ret < 0)
408 				return ret;
409 		}
410 	}
411 
412 	/* Switch to page addressing mode */
413 	if (ssd130x->page_address_mode)
414 		return ssd130x_write_cmd(ssd130x, 2, SSD130X_SET_ADDRESS_MODE,
415 					 SSD130X_SET_ADDRESS_MODE_PAGE);
416 
417 	/* Switch to horizontal addressing mode */
418 	return ssd130x_write_cmd(ssd130x, 2, SSD130X_SET_ADDRESS_MODE,
419 				 SSD130X_SET_ADDRESS_MODE_HORIZONTAL);
420 }
421 
422 static int ssd130x_update_rect(struct ssd130x_device *ssd130x, u8 *buf,
423 			       struct drm_rect *rect)
424 {
425 	unsigned int x = rect->x1;
426 	unsigned int y = rect->y1;
427 	unsigned int width = drm_rect_width(rect);
428 	unsigned int height = drm_rect_height(rect);
429 	unsigned int line_length = DIV_ROUND_UP(width, 8);
430 	unsigned int pages = DIV_ROUND_UP(height, 8);
431 	struct drm_device *drm = &ssd130x->drm;
432 	u32 array_idx = 0;
433 	int ret, i, j, k;
434 	u8 *data_array = NULL;
435 
436 	drm_WARN_ONCE(drm, y % 8 != 0, "y must be aligned to screen page\n");
437 
438 	data_array = kcalloc(width, pages, GFP_KERNEL);
439 	if (!data_array)
440 		return -ENOMEM;
441 
442 	/*
443 	 * The screen is divided in pages, each having a height of 8
444 	 * pixels, and the width of the screen. When sending a byte of
445 	 * data to the controller, it gives the 8 bits for the current
446 	 * column. I.e, the first byte are the 8 bits of the first
447 	 * column, then the 8 bits for the second column, etc.
448 	 *
449 	 *
450 	 * Representation of the screen, assuming it is 5 bits
451 	 * wide. Each letter-number combination is a bit that controls
452 	 * one pixel.
453 	 *
454 	 * A0 A1 A2 A3 A4
455 	 * B0 B1 B2 B3 B4
456 	 * C0 C1 C2 C3 C4
457 	 * D0 D1 D2 D3 D4
458 	 * E0 E1 E2 E3 E4
459 	 * F0 F1 F2 F3 F4
460 	 * G0 G1 G2 G3 G4
461 	 * H0 H1 H2 H3 H4
462 	 *
463 	 * If you want to update this screen, you need to send 5 bytes:
464 	 *  (1) A0 B0 C0 D0 E0 F0 G0 H0
465 	 *  (2) A1 B1 C1 D1 E1 F1 G1 H1
466 	 *  (3) A2 B2 C2 D2 E2 F2 G2 H2
467 	 *  (4) A3 B3 C3 D3 E3 F3 G3 H3
468 	 *  (5) A4 B4 C4 D4 E4 F4 G4 H4
469 	 */
470 
471 	if (!ssd130x->page_address_mode) {
472 		/* Set address range for horizontal addressing mode */
473 		ret = ssd130x_set_col_range(ssd130x, ssd130x->col_offset + x, width);
474 		if (ret < 0)
475 			goto out_free;
476 
477 		ret = ssd130x_set_page_range(ssd130x, ssd130x->page_offset + y / 8, pages);
478 		if (ret < 0)
479 			goto out_free;
480 	}
481 
482 	for (i = 0; i < pages; i++) {
483 		int m = 8;
484 
485 		/* Last page may be partial */
486 		if (8 * (y / 8 + i + 1) > ssd130x->height)
487 			m = ssd130x->height % 8;
488 		for (j = 0; j < width; j++) {
489 			u8 data = 0;
490 
491 			for (k = 0; k < m; k++) {
492 				u8 byte = buf[(8 * i + k) * line_length + j / 8];
493 				u8 bit = (byte >> (j % 8)) & 1;
494 
495 				data |= bit << k;
496 			}
497 			data_array[array_idx++] = data;
498 		}
499 
500 		/*
501 		 * In page addressing mode, the start address needs to be reset,
502 		 * and each page then needs to be written out separately.
503 		 */
504 		if (ssd130x->page_address_mode) {
505 			ret = ssd130x_set_page_pos(ssd130x,
506 						   ssd130x->page_offset + i,
507 						   ssd130x->col_offset + x);
508 			if (ret < 0)
509 				goto out_free;
510 
511 			ret = ssd130x_write_data(ssd130x, data_array, width);
512 			if (ret < 0)
513 				goto out_free;
514 
515 			array_idx = 0;
516 		}
517 	}
518 
519 	/* Write out update in one go if we aren't using page addressing mode */
520 	if (!ssd130x->page_address_mode)
521 		ret = ssd130x_write_data(ssd130x, data_array, width * pages);
522 
523 out_free:
524 	kfree(data_array);
525 	return ret;
526 }
527 
528 static void ssd130x_clear_screen(struct ssd130x_device *ssd130x)
529 {
530 	u8 *buf = NULL;
531 	struct drm_rect fullscreen = {
532 		.x1 = 0,
533 		.x2 = ssd130x->width,
534 		.y1 = 0,
535 		.y2 = ssd130x->height,
536 	};
537 
538 	buf = kcalloc(DIV_ROUND_UP(ssd130x->width, 8), ssd130x->height,
539 		      GFP_KERNEL);
540 	if (!buf)
541 		return;
542 
543 	ssd130x_update_rect(ssd130x, buf, &fullscreen);
544 
545 	kfree(buf);
546 }
547 
548 static int ssd130x_fb_blit_rect(struct drm_framebuffer *fb, const struct iosys_map *vmap,
549 				struct drm_rect *rect)
550 {
551 	struct ssd130x_device *ssd130x = drm_to_ssd130x(fb->dev);
552 	struct iosys_map dst;
553 	unsigned int dst_pitch;
554 	int ret = 0;
555 	u8 *buf = NULL;
556 
557 	/* Align y to display page boundaries */
558 	rect->y1 = round_down(rect->y1, 8);
559 	rect->y2 = min_t(unsigned int, round_up(rect->y2, 8), ssd130x->height);
560 
561 	dst_pitch = DIV_ROUND_UP(drm_rect_width(rect), 8);
562 	buf = kcalloc(dst_pitch, drm_rect_height(rect), GFP_KERNEL);
563 	if (!buf)
564 		return -ENOMEM;
565 
566 	ret = drm_gem_fb_begin_cpu_access(fb, DMA_FROM_DEVICE);
567 	if (ret)
568 		goto out_free;
569 
570 	iosys_map_set_vaddr(&dst, buf);
571 	drm_fb_xrgb8888_to_mono(&dst, &dst_pitch, vmap, fb, rect);
572 
573 	drm_gem_fb_end_cpu_access(fb, DMA_FROM_DEVICE);
574 
575 	ssd130x_update_rect(ssd130x, buf, rect);
576 
577 out_free:
578 	kfree(buf);
579 
580 	return ret;
581 }
582 
583 static void ssd130x_primary_plane_helper_atomic_update(struct drm_plane *plane,
584 						       struct drm_atomic_state *state)
585 {
586 	struct drm_plane_state *plane_state = drm_atomic_get_new_plane_state(state, plane);
587 	struct drm_plane_state *old_plane_state = drm_atomic_get_old_plane_state(state, plane);
588 	struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(plane_state);
589 	struct drm_atomic_helper_damage_iter iter;
590 	struct drm_device *drm = plane->dev;
591 	struct drm_rect dst_clip;
592 	struct drm_rect damage;
593 	int idx;
594 
595 	if (!drm_dev_enter(drm, &idx))
596 		return;
597 
598 	drm_atomic_helper_damage_iter_init(&iter, old_plane_state, plane_state);
599 	drm_atomic_for_each_plane_damage(&iter, &damage) {
600 		dst_clip = plane_state->dst;
601 
602 		if (!drm_rect_intersect(&dst_clip, &damage))
603 			continue;
604 
605 		ssd130x_fb_blit_rect(plane_state->fb, &shadow_plane_state->data[0], &dst_clip);
606 	}
607 
608 	drm_dev_exit(idx);
609 }
610 
611 static void ssd130x_primary_plane_helper_atomic_disable(struct drm_plane *plane,
612 							struct drm_atomic_state *state)
613 {
614 	struct drm_device *drm = plane->dev;
615 	struct ssd130x_device *ssd130x = drm_to_ssd130x(drm);
616 	int idx;
617 
618 	if (!drm_dev_enter(drm, &idx))
619 		return;
620 
621 	ssd130x_clear_screen(ssd130x);
622 
623 	drm_dev_exit(idx);
624 }
625 
626 static const struct drm_plane_helper_funcs ssd130x_primary_plane_helper_funcs = {
627 	DRM_GEM_SHADOW_PLANE_HELPER_FUNCS,
628 	.atomic_check = drm_plane_helper_atomic_check,
629 	.atomic_update = ssd130x_primary_plane_helper_atomic_update,
630 	.atomic_disable = ssd130x_primary_plane_helper_atomic_disable,
631 };
632 
633 static const struct drm_plane_funcs ssd130x_primary_plane_funcs = {
634 	.update_plane = drm_atomic_helper_update_plane,
635 	.disable_plane = drm_atomic_helper_disable_plane,
636 	.destroy = drm_plane_cleanup,
637 	DRM_GEM_SHADOW_PLANE_FUNCS,
638 };
639 
640 static enum drm_mode_status ssd130x_crtc_helper_mode_valid(struct drm_crtc *crtc,
641 							   const struct drm_display_mode *mode)
642 {
643 	struct ssd130x_device *ssd130x = drm_to_ssd130x(crtc->dev);
644 
645 	if (mode->hdisplay != ssd130x->mode.hdisplay &&
646 	    mode->vdisplay != ssd130x->mode.vdisplay)
647 		return MODE_ONE_SIZE;
648 	else if (mode->hdisplay != ssd130x->mode.hdisplay)
649 		return MODE_ONE_WIDTH;
650 	else if (mode->vdisplay != ssd130x->mode.vdisplay)
651 		return MODE_ONE_HEIGHT;
652 
653 	return MODE_OK;
654 }
655 
656 /*
657  * The CRTC is always enabled. Screen updates are performed by
658  * the primary plane's atomic_update function. Disabling clears
659  * the screen in the primary plane's atomic_disable function.
660  */
661 static const struct drm_crtc_helper_funcs ssd130x_crtc_helper_funcs = {
662 	.mode_valid = ssd130x_crtc_helper_mode_valid,
663 	.atomic_check = drm_crtc_helper_atomic_check,
664 };
665 
666 static const struct drm_crtc_funcs ssd130x_crtc_funcs = {
667 	.reset = drm_atomic_helper_crtc_reset,
668 	.destroy = drm_crtc_cleanup,
669 	.set_config = drm_atomic_helper_set_config,
670 	.page_flip = drm_atomic_helper_page_flip,
671 	.atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
672 	.atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
673 };
674 
675 static void ssd130x_encoder_helper_atomic_enable(struct drm_encoder *encoder,
676 						 struct drm_atomic_state *state)
677 {
678 	struct drm_device *drm = encoder->dev;
679 	struct ssd130x_device *ssd130x = drm_to_ssd130x(drm);
680 	int ret;
681 
682 	ret = ssd130x_power_on(ssd130x);
683 	if (ret)
684 		return;
685 
686 	ret = ssd130x_init(ssd130x);
687 	if (ret) {
688 		ssd130x_power_off(ssd130x);
689 		return;
690 	}
691 
692 	ssd130x_write_cmd(ssd130x, 1, SSD130X_DISPLAY_ON);
693 
694 	backlight_enable(ssd130x->bl_dev);
695 }
696 
697 static void ssd130x_encoder_helper_atomic_disable(struct drm_encoder *encoder,
698 						  struct drm_atomic_state *state)
699 {
700 	struct drm_device *drm = encoder->dev;
701 	struct ssd130x_device *ssd130x = drm_to_ssd130x(drm);
702 
703 	backlight_disable(ssd130x->bl_dev);
704 
705 	ssd130x_write_cmd(ssd130x, 1, SSD130X_DISPLAY_OFF);
706 
707 	ssd130x_power_off(ssd130x);
708 }
709 
710 static const struct drm_encoder_helper_funcs ssd130x_encoder_helper_funcs = {
711 	.atomic_enable = ssd130x_encoder_helper_atomic_enable,
712 	.atomic_disable = ssd130x_encoder_helper_atomic_disable,
713 };
714 
715 static const struct drm_encoder_funcs ssd130x_encoder_funcs = {
716 	.destroy = drm_encoder_cleanup,
717 };
718 
719 static int ssd130x_connector_helper_get_modes(struct drm_connector *connector)
720 {
721 	struct ssd130x_device *ssd130x = drm_to_ssd130x(connector->dev);
722 	struct drm_display_mode *mode;
723 	struct device *dev = ssd130x->dev;
724 
725 	mode = drm_mode_duplicate(connector->dev, &ssd130x->mode);
726 	if (!mode) {
727 		dev_err(dev, "Failed to duplicated mode\n");
728 		return 0;
729 	}
730 
731 	drm_mode_probed_add(connector, mode);
732 	drm_set_preferred_mode(connector, mode->hdisplay, mode->vdisplay);
733 
734 	/* There is only a single mode */
735 	return 1;
736 }
737 
738 static const struct drm_connector_helper_funcs ssd130x_connector_helper_funcs = {
739 	.get_modes = ssd130x_connector_helper_get_modes,
740 };
741 
742 static const struct drm_connector_funcs ssd130x_connector_funcs = {
743 	.reset = drm_atomic_helper_connector_reset,
744 	.fill_modes = drm_helper_probe_single_connector_modes,
745 	.destroy = drm_connector_cleanup,
746 	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
747 	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
748 };
749 
750 static const struct drm_mode_config_funcs ssd130x_mode_config_funcs = {
751 	.fb_create = drm_gem_fb_create_with_dirty,
752 	.atomic_check = drm_atomic_helper_check,
753 	.atomic_commit = drm_atomic_helper_commit,
754 };
755 
756 static const uint32_t ssd130x_formats[] = {
757 	DRM_FORMAT_XRGB8888,
758 };
759 
760 DEFINE_DRM_GEM_FOPS(ssd130x_fops);
761 
762 static const struct drm_driver ssd130x_drm_driver = {
763 	DRM_GEM_SHMEM_DRIVER_OPS,
764 	.name			= DRIVER_NAME,
765 	.desc			= DRIVER_DESC,
766 	.date			= DRIVER_DATE,
767 	.major			= DRIVER_MAJOR,
768 	.minor			= DRIVER_MINOR,
769 	.driver_features	= DRIVER_ATOMIC | DRIVER_GEM | DRIVER_MODESET,
770 	.fops			= &ssd130x_fops,
771 };
772 
773 static int ssd130x_update_bl(struct backlight_device *bdev)
774 {
775 	struct ssd130x_device *ssd130x = bl_get_data(bdev);
776 	int brightness = backlight_get_brightness(bdev);
777 	int ret;
778 
779 	ssd130x->contrast = brightness;
780 
781 	ret = ssd130x_write_cmd(ssd130x, 1, SSD130X_CONTRAST);
782 	if (ret < 0)
783 		return ret;
784 
785 	ret = ssd130x_write_cmd(ssd130x, 1, ssd130x->contrast);
786 	if (ret < 0)
787 		return ret;
788 
789 	return 0;
790 }
791 
792 static const struct backlight_ops ssd130xfb_bl_ops = {
793 	.update_status	= ssd130x_update_bl,
794 };
795 
796 static void ssd130x_parse_properties(struct ssd130x_device *ssd130x)
797 {
798 	struct device *dev = ssd130x->dev;
799 
800 	if (device_property_read_u32(dev, "solomon,width", &ssd130x->width))
801 		ssd130x->width = 96;
802 
803 	if (device_property_read_u32(dev, "solomon,height", &ssd130x->height))
804 		ssd130x->height = 16;
805 
806 	if (device_property_read_u32(dev, "solomon,page-offset", &ssd130x->page_offset))
807 		ssd130x->page_offset = 1;
808 
809 	if (device_property_read_u32(dev, "solomon,col-offset", &ssd130x->col_offset))
810 		ssd130x->col_offset = 0;
811 
812 	if (device_property_read_u32(dev, "solomon,com-offset", &ssd130x->com_offset))
813 		ssd130x->com_offset = 0;
814 
815 	if (device_property_read_u32(dev, "solomon,prechargep1", &ssd130x->prechargep1))
816 		ssd130x->prechargep1 = 2;
817 
818 	if (device_property_read_u32(dev, "solomon,prechargep2", &ssd130x->prechargep2))
819 		ssd130x->prechargep2 = 2;
820 
821 	if (!device_property_read_u8_array(dev, "solomon,lookup-table",
822 					   ssd130x->lookup_table,
823 					   ARRAY_SIZE(ssd130x->lookup_table)))
824 		ssd130x->lookup_table_set = 1;
825 
826 	ssd130x->seg_remap = !device_property_read_bool(dev, "solomon,segment-no-remap");
827 	ssd130x->com_seq = device_property_read_bool(dev, "solomon,com-seq");
828 	ssd130x->com_lrremap = device_property_read_bool(dev, "solomon,com-lrremap");
829 	ssd130x->com_invdir = device_property_read_bool(dev, "solomon,com-invdir");
830 	ssd130x->area_color_enable =
831 		device_property_read_bool(dev, "solomon,area-color-enable");
832 	ssd130x->low_power = device_property_read_bool(dev, "solomon,low-power");
833 
834 	ssd130x->contrast = 127;
835 	ssd130x->vcomh = ssd130x->device_info->default_vcomh;
836 
837 	/* Setup display timing */
838 	if (device_property_read_u32(dev, "solomon,dclk-div", &ssd130x->dclk_div))
839 		ssd130x->dclk_div = ssd130x->device_info->default_dclk_div;
840 	if (device_property_read_u32(dev, "solomon,dclk-frq", &ssd130x->dclk_frq))
841 		ssd130x->dclk_frq = ssd130x->device_info->default_dclk_frq;
842 }
843 
844 static int ssd130x_init_modeset(struct ssd130x_device *ssd130x)
845 {
846 	struct drm_display_mode *mode = &ssd130x->mode;
847 	struct device *dev = ssd130x->dev;
848 	struct drm_device *drm = &ssd130x->drm;
849 	unsigned long max_width, max_height;
850 	struct drm_plane *primary_plane;
851 	struct drm_crtc *crtc;
852 	struct drm_encoder *encoder;
853 	struct drm_connector *connector;
854 	int ret;
855 
856 	/*
857 	 * Modesetting
858 	 */
859 
860 	ret = drmm_mode_config_init(drm);
861 	if (ret) {
862 		dev_err(dev, "DRM mode config init failed: %d\n", ret);
863 		return ret;
864 	}
865 
866 	mode->type = DRM_MODE_TYPE_DRIVER;
867 	mode->clock = 1;
868 	mode->hdisplay = mode->htotal = ssd130x->width;
869 	mode->hsync_start = mode->hsync_end = ssd130x->width;
870 	mode->vdisplay = mode->vtotal = ssd130x->height;
871 	mode->vsync_start = mode->vsync_end = ssd130x->height;
872 	mode->width_mm = 27;
873 	mode->height_mm = 27;
874 
875 	max_width = max_t(unsigned long, mode->hdisplay, DRM_SHADOW_PLANE_MAX_WIDTH);
876 	max_height = max_t(unsigned long, mode->vdisplay, DRM_SHADOW_PLANE_MAX_HEIGHT);
877 
878 	drm->mode_config.min_width = mode->hdisplay;
879 	drm->mode_config.max_width = max_width;
880 	drm->mode_config.min_height = mode->vdisplay;
881 	drm->mode_config.max_height = max_height;
882 	drm->mode_config.preferred_depth = 24;
883 	drm->mode_config.funcs = &ssd130x_mode_config_funcs;
884 
885 	/* Primary plane */
886 
887 	primary_plane = &ssd130x->primary_plane;
888 	ret = drm_universal_plane_init(drm, primary_plane, 0, &ssd130x_primary_plane_funcs,
889 				       ssd130x_formats, ARRAY_SIZE(ssd130x_formats),
890 				       NULL, DRM_PLANE_TYPE_PRIMARY, NULL);
891 	if (ret) {
892 		dev_err(dev, "DRM primary plane init failed: %d\n", ret);
893 		return ret;
894 	}
895 
896 	drm_plane_helper_add(primary_plane, &ssd130x_primary_plane_helper_funcs);
897 
898 	drm_plane_enable_fb_damage_clips(primary_plane);
899 
900 	/* CRTC */
901 
902 	crtc = &ssd130x->crtc;
903 	ret = drm_crtc_init_with_planes(drm, crtc, primary_plane, NULL,
904 					&ssd130x_crtc_funcs, NULL);
905 	if (ret) {
906 		dev_err(dev, "DRM crtc init failed: %d\n", ret);
907 		return ret;
908 	}
909 
910 	drm_crtc_helper_add(crtc, &ssd130x_crtc_helper_funcs);
911 
912 	/* Encoder */
913 
914 	encoder = &ssd130x->encoder;
915 	ret = drm_encoder_init(drm, encoder, &ssd130x_encoder_funcs,
916 			       DRM_MODE_ENCODER_NONE, NULL);
917 	if (ret) {
918 		dev_err(dev, "DRM encoder init failed: %d\n", ret);
919 		return ret;
920 	}
921 
922 	drm_encoder_helper_add(encoder, &ssd130x_encoder_helper_funcs);
923 
924 	encoder->possible_crtcs = drm_crtc_mask(crtc);
925 
926 	/* Connector */
927 
928 	connector = &ssd130x->connector;
929 	ret = drm_connector_init(drm, connector, &ssd130x_connector_funcs,
930 				 DRM_MODE_CONNECTOR_Unknown);
931 	if (ret) {
932 		dev_err(dev, "DRM connector init failed: %d\n", ret);
933 		return ret;
934 	}
935 
936 	drm_connector_helper_add(connector, &ssd130x_connector_helper_funcs);
937 
938 	ret = drm_connector_attach_encoder(connector, encoder);
939 	if (ret) {
940 		dev_err(dev, "DRM attach connector to encoder failed: %d\n", ret);
941 		return ret;
942 	}
943 
944 	drm_mode_config_reset(drm);
945 
946 	return 0;
947 }
948 
949 static int ssd130x_get_resources(struct ssd130x_device *ssd130x)
950 {
951 	struct device *dev = ssd130x->dev;
952 
953 	ssd130x->reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
954 	if (IS_ERR(ssd130x->reset))
955 		return dev_err_probe(dev, PTR_ERR(ssd130x->reset),
956 				     "Failed to get reset gpio\n");
957 
958 	ssd130x->vcc_reg = devm_regulator_get(dev, "vcc");
959 	if (IS_ERR(ssd130x->vcc_reg))
960 		return dev_err_probe(dev, PTR_ERR(ssd130x->vcc_reg),
961 				     "Failed to get VCC regulator\n");
962 
963 	return 0;
964 }
965 
966 struct ssd130x_device *ssd130x_probe(struct device *dev, struct regmap *regmap)
967 {
968 	struct ssd130x_device *ssd130x;
969 	struct backlight_device *bl;
970 	struct drm_device *drm;
971 	int ret;
972 
973 	ssd130x = devm_drm_dev_alloc(dev, &ssd130x_drm_driver,
974 				     struct ssd130x_device, drm);
975 	if (IS_ERR(ssd130x))
976 		return ERR_PTR(dev_err_probe(dev, PTR_ERR(ssd130x),
977 					     "Failed to allocate DRM device\n"));
978 
979 	drm = &ssd130x->drm;
980 
981 	ssd130x->dev = dev;
982 	ssd130x->regmap = regmap;
983 	ssd130x->device_info = device_get_match_data(dev);
984 
985 	if (ssd130x->device_info->page_mode_only)
986 		ssd130x->page_address_mode = 1;
987 
988 	ssd130x_parse_properties(ssd130x);
989 
990 	ret = ssd130x_get_resources(ssd130x);
991 	if (ret)
992 		return ERR_PTR(ret);
993 
994 	bl = devm_backlight_device_register(dev, dev_name(dev), dev, ssd130x,
995 					    &ssd130xfb_bl_ops, NULL);
996 	if (IS_ERR(bl))
997 		return ERR_PTR(dev_err_probe(dev, PTR_ERR(bl),
998 					     "Unable to register backlight device\n"));
999 
1000 	bl->props.brightness = ssd130x->contrast;
1001 	bl->props.max_brightness = MAX_CONTRAST;
1002 	ssd130x->bl_dev = bl;
1003 
1004 	ret = ssd130x_init_modeset(ssd130x);
1005 	if (ret)
1006 		return ERR_PTR(ret);
1007 
1008 	ret = drm_dev_register(drm, 0);
1009 	if (ret)
1010 		return ERR_PTR(dev_err_probe(dev, ret, "DRM device register failed\n"));
1011 
1012 	drm_fbdev_generic_setup(drm, 32);
1013 
1014 	return ssd130x;
1015 }
1016 EXPORT_SYMBOL_GPL(ssd130x_probe);
1017 
1018 void ssd130x_remove(struct ssd130x_device *ssd130x)
1019 {
1020 	drm_dev_unplug(&ssd130x->drm);
1021 }
1022 EXPORT_SYMBOL_GPL(ssd130x_remove);
1023 
1024 void ssd130x_shutdown(struct ssd130x_device *ssd130x)
1025 {
1026 	drm_atomic_helper_shutdown(&ssd130x->drm);
1027 }
1028 EXPORT_SYMBOL_GPL(ssd130x_shutdown);
1029 
1030 MODULE_DESCRIPTION(DRIVER_DESC);
1031 MODULE_AUTHOR("Javier Martinez Canillas <javierm@redhat.com>");
1032 MODULE_LICENSE("GPL v2");
1033