xref: /openbmc/linux/drivers/gpu/drm/solomon/ssd130x.c (revision 4cd179a312c60587ab15792f04febae3bed5459b)
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 		.default_width = 132,
103 		.default_height = 64,
104 		.page_mode_only = 1,
105 		.page_height = 8,
106 	},
107 	[SSD1305_ID] = {
108 		.default_vcomh = 0x34,
109 		.default_dclk_div = 1,
110 		.default_dclk_frq = 7,
111 		.default_width = 132,
112 		.default_height = 64,
113 		.page_height = 8,
114 	},
115 	[SSD1306_ID] = {
116 		.default_vcomh = 0x20,
117 		.default_dclk_div = 1,
118 		.default_dclk_frq = 8,
119 		.need_chargepump = 1,
120 		.default_width = 128,
121 		.default_height = 64,
122 		.page_height = 8,
123 	},
124 	[SSD1307_ID] = {
125 		.default_vcomh = 0x20,
126 		.default_dclk_div = 2,
127 		.default_dclk_frq = 12,
128 		.need_pwm = 1,
129 		.default_width = 128,
130 		.default_height = 39,
131 		.page_height = 8,
132 	},
133 	[SSD1309_ID] = {
134 		.default_vcomh = 0x34,
135 		.default_dclk_div = 1,
136 		.default_dclk_frq = 10,
137 		.default_width = 128,
138 		.default_height = 64,
139 		.page_height = 8,
140 	}
141 };
142 EXPORT_SYMBOL_NS_GPL(ssd130x_variants, DRM_SSD130X);
143 
144 static inline struct ssd130x_device *drm_to_ssd130x(struct drm_device *drm)
145 {
146 	return container_of(drm, struct ssd130x_device, drm);
147 }
148 
149 /*
150  * Helper to write data (SSD130X_DATA) to the device.
151  */
152 static int ssd130x_write_data(struct ssd130x_device *ssd130x, u8 *values, int count)
153 {
154 	return regmap_bulk_write(ssd130x->regmap, SSD130X_DATA, values, count);
155 }
156 
157 /*
158  * Helper to write command (SSD130X_COMMAND). The fist variadic argument
159  * is the command to write and the following are the command options.
160  *
161  * Note that the ssd130x protocol requires each command and option to be
162  * written as a SSD130X_COMMAND device register value. That is why a call
163  * to regmap_write(..., SSD130X_COMMAND, ...) is done for each argument.
164  */
165 static int ssd130x_write_cmd(struct ssd130x_device *ssd130x, int count,
166 			     /* u8 cmd, u8 option, ... */...)
167 {
168 	va_list ap;
169 	u8 value;
170 	int ret;
171 
172 	va_start(ap, count);
173 
174 	do {
175 		value = va_arg(ap, int);
176 		ret = regmap_write(ssd130x->regmap, SSD130X_COMMAND, value);
177 		if (ret)
178 			goto out_end;
179 	} while (--count);
180 
181 out_end:
182 	va_end(ap);
183 
184 	return ret;
185 }
186 
187 /* Set address range for horizontal/vertical addressing modes */
188 static int ssd130x_set_col_range(struct ssd130x_device *ssd130x,
189 				 u8 col_start, u8 cols)
190 {
191 	u8 col_end = col_start + cols - 1;
192 	int ret;
193 
194 	if (col_start == ssd130x->col_start && col_end == ssd130x->col_end)
195 		return 0;
196 
197 	ret = ssd130x_write_cmd(ssd130x, 3, SSD130X_SET_COL_RANGE, col_start, col_end);
198 	if (ret < 0)
199 		return ret;
200 
201 	ssd130x->col_start = col_start;
202 	ssd130x->col_end = col_end;
203 	return 0;
204 }
205 
206 static int ssd130x_set_page_range(struct ssd130x_device *ssd130x,
207 				  u8 page_start, u8 pages)
208 {
209 	u8 page_end = page_start + pages - 1;
210 	int ret;
211 
212 	if (page_start == ssd130x->page_start && page_end == ssd130x->page_end)
213 		return 0;
214 
215 	ret = ssd130x_write_cmd(ssd130x, 3, SSD130X_SET_PAGE_RANGE, page_start, page_end);
216 	if (ret < 0)
217 		return ret;
218 
219 	ssd130x->page_start = page_start;
220 	ssd130x->page_end = page_end;
221 	return 0;
222 }
223 
224 /* Set page and column start address for page addressing mode */
225 static int ssd130x_set_page_pos(struct ssd130x_device *ssd130x,
226 				u8 page_start, u8 col_start)
227 {
228 	int ret;
229 	u32 page, col_low, col_high;
230 
231 	page = SSD130X_START_PAGE_ADDRESS |
232 	       SSD130X_START_PAGE_ADDRESS_SET(page_start);
233 	col_low = SSD130X_PAGE_COL_START_LOW |
234 		  SSD130X_PAGE_COL_START_LOW_SET(col_start);
235 	col_high = SSD130X_PAGE_COL_START_HIGH |
236 		   SSD130X_PAGE_COL_START_HIGH_SET(col_start);
237 	ret = ssd130x_write_cmd(ssd130x, 3, page, col_low, col_high);
238 	if (ret < 0)
239 		return ret;
240 
241 	return 0;
242 }
243 
244 static int ssd130x_pwm_enable(struct ssd130x_device *ssd130x)
245 {
246 	struct device *dev = ssd130x->dev;
247 	struct pwm_state pwmstate;
248 
249 	ssd130x->pwm = pwm_get(dev, NULL);
250 	if (IS_ERR(ssd130x->pwm)) {
251 		dev_err(dev, "Could not get PWM from firmware description!\n");
252 		return PTR_ERR(ssd130x->pwm);
253 	}
254 
255 	pwm_init_state(ssd130x->pwm, &pwmstate);
256 	pwm_set_relative_duty_cycle(&pwmstate, 50, 100);
257 	pwm_apply_state(ssd130x->pwm, &pwmstate);
258 
259 	/* Enable the PWM */
260 	pwm_enable(ssd130x->pwm);
261 
262 	dev_dbg(dev, "Using PWM%d with a %lluns period.\n",
263 		ssd130x->pwm->pwm, pwm_get_period(ssd130x->pwm));
264 
265 	return 0;
266 }
267 
268 static void ssd130x_reset(struct ssd130x_device *ssd130x)
269 {
270 	if (!ssd130x->reset)
271 		return;
272 
273 	/* Reset the screen */
274 	gpiod_set_value_cansleep(ssd130x->reset, 1);
275 	udelay(4);
276 	gpiod_set_value_cansleep(ssd130x->reset, 0);
277 	udelay(4);
278 }
279 
280 static int ssd130x_power_on(struct ssd130x_device *ssd130x)
281 {
282 	struct device *dev = ssd130x->dev;
283 	int ret;
284 
285 	ssd130x_reset(ssd130x);
286 
287 	ret = regulator_enable(ssd130x->vcc_reg);
288 	if (ret) {
289 		dev_err(dev, "Failed to enable VCC: %d\n", ret);
290 		return ret;
291 	}
292 
293 	if (ssd130x->device_info->need_pwm) {
294 		ret = ssd130x_pwm_enable(ssd130x);
295 		if (ret) {
296 			dev_err(dev, "Failed to enable PWM: %d\n", ret);
297 			regulator_disable(ssd130x->vcc_reg);
298 			return ret;
299 		}
300 	}
301 
302 	return 0;
303 }
304 
305 static void ssd130x_power_off(struct ssd130x_device *ssd130x)
306 {
307 	pwm_disable(ssd130x->pwm);
308 	pwm_put(ssd130x->pwm);
309 
310 	regulator_disable(ssd130x->vcc_reg);
311 }
312 
313 static int ssd130x_init(struct ssd130x_device *ssd130x)
314 {
315 	u32 precharge, dclk, com_invdir, compins, chargepump, seg_remap;
316 	bool scan_mode;
317 	int ret;
318 
319 	/* Set initial contrast */
320 	ret = ssd130x_write_cmd(ssd130x, 2, SSD130X_CONTRAST, ssd130x->contrast);
321 	if (ret < 0)
322 		return ret;
323 
324 	/* Set segment re-map */
325 	seg_remap = (SSD130X_SET_SEG_REMAP |
326 		     SSD130X_SET_SEG_REMAP_SET(ssd130x->seg_remap));
327 	ret = ssd130x_write_cmd(ssd130x, 1, seg_remap);
328 	if (ret < 0)
329 		return ret;
330 
331 	/* Set COM direction */
332 	com_invdir = (SSD130X_SET_COM_SCAN_DIR |
333 		      SSD130X_SET_COM_SCAN_DIR_SET(ssd130x->com_invdir));
334 	ret = ssd130x_write_cmd(ssd130x,  1, com_invdir);
335 	if (ret < 0)
336 		return ret;
337 
338 	/* Set multiplex ratio value */
339 	ret = ssd130x_write_cmd(ssd130x, 2, SSD130X_SET_MULTIPLEX_RATIO, ssd130x->height - 1);
340 	if (ret < 0)
341 		return ret;
342 
343 	/* set display offset value */
344 	ret = ssd130x_write_cmd(ssd130x, 2, SSD130X_SET_DISPLAY_OFFSET, ssd130x->com_offset);
345 	if (ret < 0)
346 		return ret;
347 
348 	/* Set clock frequency */
349 	dclk = (SSD130X_SET_CLOCK_DIV_SET(ssd130x->dclk_div - 1) |
350 		SSD130X_SET_CLOCK_FREQ_SET(ssd130x->dclk_frq));
351 	ret = ssd130x_write_cmd(ssd130x, 2, SSD130X_SET_CLOCK_FREQ, dclk);
352 	if (ret < 0)
353 		return ret;
354 
355 	/* Set Area Color Mode ON/OFF & Low Power Display Mode */
356 	if (ssd130x->area_color_enable || ssd130x->low_power) {
357 		u32 mode = 0;
358 
359 		if (ssd130x->area_color_enable)
360 			mode |= SSD130X_SET_AREA_COLOR_MODE_ENABLE;
361 
362 		if (ssd130x->low_power)
363 			mode |= SSD130X_SET_AREA_COLOR_MODE_LOW_POWER;
364 
365 		ret = ssd130x_write_cmd(ssd130x, 2, SSD130X_SET_AREA_COLOR_MODE, mode);
366 		if (ret < 0)
367 			return ret;
368 	}
369 
370 	/* Set precharge period in number of ticks from the internal clock */
371 	precharge = (SSD130X_SET_PRECHARGE_PERIOD1_SET(ssd130x->prechargep1) |
372 		     SSD130X_SET_PRECHARGE_PERIOD2_SET(ssd130x->prechargep2));
373 	ret = ssd130x_write_cmd(ssd130x, 2, SSD130X_SET_PRECHARGE_PERIOD, precharge);
374 	if (ret < 0)
375 		return ret;
376 
377 	/* Set COM pins configuration */
378 	compins = BIT(1);
379 	/*
380 	 * The COM scan mode field values are the inverse of the boolean DT
381 	 * property "solomon,com-seq". The value 0b means scan from COM0 to
382 	 * COM[N - 1] while 1b means scan from COM[N - 1] to COM0.
383 	 */
384 	scan_mode = !ssd130x->com_seq;
385 	compins |= (SSD130X_SET_COM_PINS_CONFIG1_SET(scan_mode) |
386 		    SSD130X_SET_COM_PINS_CONFIG2_SET(ssd130x->com_lrremap));
387 	ret = ssd130x_write_cmd(ssd130x, 2, SSD130X_SET_COM_PINS_CONFIG, compins);
388 	if (ret < 0)
389 		return ret;
390 
391 	/* Set VCOMH */
392 	ret = ssd130x_write_cmd(ssd130x, 2, SSD130X_SET_VCOMH, ssd130x->vcomh);
393 	if (ret < 0)
394 		return ret;
395 
396 	/* Turn on the DC-DC Charge Pump */
397 	chargepump = BIT(4);
398 
399 	if (ssd130x->device_info->need_chargepump)
400 		chargepump |= BIT(2);
401 
402 	ret = ssd130x_write_cmd(ssd130x, 2, SSD130X_CHARGE_PUMP, chargepump);
403 	if (ret < 0)
404 		return ret;
405 
406 	/* Set lookup table */
407 	if (ssd130x->lookup_table_set) {
408 		int i;
409 
410 		ret = ssd130x_write_cmd(ssd130x, 1, SSD130X_SET_LOOKUP_TABLE);
411 		if (ret < 0)
412 			return ret;
413 
414 		for (i = 0; i < ARRAY_SIZE(ssd130x->lookup_table); i++) {
415 			u8 val = ssd130x->lookup_table[i];
416 
417 			if (val < 31 || val > 63)
418 				dev_warn(ssd130x->dev,
419 					 "lookup table index %d value out of range 31 <= %d <= 63\n",
420 					 i, val);
421 			ret = ssd130x_write_cmd(ssd130x, 1, val);
422 			if (ret < 0)
423 				return ret;
424 		}
425 	}
426 
427 	/* Switch to page addressing mode */
428 	if (ssd130x->page_address_mode)
429 		return ssd130x_write_cmd(ssd130x, 2, SSD130X_SET_ADDRESS_MODE,
430 					 SSD130X_SET_ADDRESS_MODE_PAGE);
431 
432 	/* Switch to horizontal addressing mode */
433 	return ssd130x_write_cmd(ssd130x, 2, SSD130X_SET_ADDRESS_MODE,
434 				 SSD130X_SET_ADDRESS_MODE_HORIZONTAL);
435 }
436 
437 static int ssd130x_update_rect(struct ssd130x_device *ssd130x, struct drm_rect *rect)
438 {
439 	unsigned int x = rect->x1;
440 	unsigned int y = rect->y1;
441 	u8 *buf = ssd130x->buffer;
442 	u8 *data_array = ssd130x->data_array;
443 	unsigned int width = drm_rect_width(rect);
444 	unsigned int height = drm_rect_height(rect);
445 	unsigned int line_length = DIV_ROUND_UP(width, 8);
446 	unsigned int page_height = ssd130x->device_info->page_height;
447 	unsigned int pages = DIV_ROUND_UP(height, page_height);
448 	struct drm_device *drm = &ssd130x->drm;
449 	u32 array_idx = 0;
450 	int ret, i, j, k;
451 
452 	drm_WARN_ONCE(drm, y % 8 != 0, "y must be aligned to screen page\n");
453 
454 	/*
455 	 * The screen is divided in pages, each having a height of 8
456 	 * pixels, and the width of the screen. When sending a byte of
457 	 * data to the controller, it gives the 8 bits for the current
458 	 * column. I.e, the first byte are the 8 bits of the first
459 	 * column, then the 8 bits for the second column, etc.
460 	 *
461 	 *
462 	 * Representation of the screen, assuming it is 5 bits
463 	 * wide. Each letter-number combination is a bit that controls
464 	 * one pixel.
465 	 *
466 	 * A0 A1 A2 A3 A4
467 	 * B0 B1 B2 B3 B4
468 	 * C0 C1 C2 C3 C4
469 	 * D0 D1 D2 D3 D4
470 	 * E0 E1 E2 E3 E4
471 	 * F0 F1 F2 F3 F4
472 	 * G0 G1 G2 G3 G4
473 	 * H0 H1 H2 H3 H4
474 	 *
475 	 * If you want to update this screen, you need to send 5 bytes:
476 	 *  (1) A0 B0 C0 D0 E0 F0 G0 H0
477 	 *  (2) A1 B1 C1 D1 E1 F1 G1 H1
478 	 *  (3) A2 B2 C2 D2 E2 F2 G2 H2
479 	 *  (4) A3 B3 C3 D3 E3 F3 G3 H3
480 	 *  (5) A4 B4 C4 D4 E4 F4 G4 H4
481 	 */
482 
483 	if (!ssd130x->page_address_mode) {
484 		/* Set address range for horizontal addressing mode */
485 		ret = ssd130x_set_col_range(ssd130x, ssd130x->col_offset + x, width);
486 		if (ret < 0)
487 			return ret;
488 
489 		ret = ssd130x_set_page_range(ssd130x, ssd130x->page_offset + y / 8, pages);
490 		if (ret < 0)
491 			return ret;
492 	}
493 
494 	for (i = 0; i < pages; i++) {
495 		int m = 8;
496 
497 		/* Last page may be partial */
498 		if (8 * (y / 8 + i + 1) > ssd130x->height)
499 			m = ssd130x->height % 8;
500 		for (j = 0; j < width; j++) {
501 			u8 data = 0;
502 
503 			for (k = 0; k < m; k++) {
504 				u8 byte = buf[(8 * i + k) * line_length + j / 8];
505 				u8 bit = (byte >> (j % 8)) & 1;
506 
507 				data |= bit << k;
508 			}
509 			data_array[array_idx++] = data;
510 		}
511 
512 		/*
513 		 * In page addressing mode, the start address needs to be reset,
514 		 * and each page then needs to be written out separately.
515 		 */
516 		if (ssd130x->page_address_mode) {
517 			ret = ssd130x_set_page_pos(ssd130x,
518 						   ssd130x->page_offset + i,
519 						   ssd130x->col_offset + x);
520 			if (ret < 0)
521 				return ret;
522 
523 			ret = ssd130x_write_data(ssd130x, data_array, width);
524 			if (ret < 0)
525 				return ret;
526 
527 			array_idx = 0;
528 		}
529 	}
530 
531 	/* Write out update in one go if we aren't using page addressing mode */
532 	if (!ssd130x->page_address_mode)
533 		ret = ssd130x_write_data(ssd130x, data_array, width * pages);
534 
535 	return ret;
536 }
537 
538 static void ssd130x_clear_screen(struct ssd130x_device *ssd130x)
539 {
540 	struct drm_rect fullscreen = {
541 		.x1 = 0,
542 		.x2 = ssd130x->width,
543 		.y1 = 0,
544 		.y2 = ssd130x->height,
545 	};
546 
547 	ssd130x_update_rect(ssd130x, &fullscreen);
548 }
549 
550 static int ssd130x_fb_blit_rect(struct drm_framebuffer *fb, const struct iosys_map *vmap,
551 				struct drm_rect *rect)
552 {
553 	struct ssd130x_device *ssd130x = drm_to_ssd130x(fb->dev);
554 	unsigned int page_height = ssd130x->device_info->page_height;
555 	struct iosys_map dst;
556 	unsigned int dst_pitch;
557 	int ret = 0;
558 	u8 *buf = ssd130x->buffer;
559 
560 	if (!buf)
561 		return 0;
562 
563 	/* Align y to display page boundaries */
564 	rect->y1 = round_down(rect->y1, page_height);
565 	rect->y2 = min_t(unsigned int, round_up(rect->y2, page_height), ssd130x->height);
566 
567 	dst_pitch = DIV_ROUND_UP(drm_rect_width(rect), 8);
568 
569 	ret = drm_gem_fb_begin_cpu_access(fb, DMA_FROM_DEVICE);
570 	if (ret)
571 		return ret;
572 
573 	iosys_map_set_vaddr(&dst, buf);
574 	drm_fb_xrgb8888_to_mono(&dst, &dst_pitch, vmap, fb, rect);
575 
576 	drm_gem_fb_end_cpu_access(fb, DMA_FROM_DEVICE);
577 
578 	ssd130x_update_rect(ssd130x, rect);
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 	unsigned int page_height = ssd130x->device_info->page_height;
681 	unsigned int pages = DIV_ROUND_UP(ssd130x->height, page_height);
682 	const struct drm_format_info *fi;
683 	unsigned int pitch;
684 	int ret;
685 
686 	ret = ssd130x_power_on(ssd130x);
687 	if (ret)
688 		return;
689 
690 	ret = ssd130x_init(ssd130x);
691 	if (ret)
692 		goto power_off;
693 
694 	fi = drm_format_info(DRM_FORMAT_R1);
695 	if (!fi)
696 		goto power_off;
697 
698 	pitch = drm_format_info_min_pitch(fi, 0, ssd130x->width);
699 
700 	ssd130x->buffer = kcalloc(pitch, ssd130x->height, GFP_KERNEL);
701 	if (!ssd130x->buffer)
702 		goto power_off;
703 
704 	ssd130x->data_array = kcalloc(ssd130x->width, pages, GFP_KERNEL);
705 	if (!ssd130x->data_array) {
706 		kfree(ssd130x->buffer);
707 		goto power_off;
708 	}
709 
710 	ssd130x_write_cmd(ssd130x, 1, SSD130X_DISPLAY_ON);
711 
712 	backlight_enable(ssd130x->bl_dev);
713 
714 	return;
715 
716 power_off:
717 	ssd130x_power_off(ssd130x);
718 	return;
719 }
720 
721 static void ssd130x_encoder_helper_atomic_disable(struct drm_encoder *encoder,
722 						  struct drm_atomic_state *state)
723 {
724 	struct drm_device *drm = encoder->dev;
725 	struct ssd130x_device *ssd130x = drm_to_ssd130x(drm);
726 
727 	backlight_disable(ssd130x->bl_dev);
728 
729 	ssd130x_write_cmd(ssd130x, 1, SSD130X_DISPLAY_OFF);
730 
731 	kfree(ssd130x->data_array);
732 	kfree(ssd130x->buffer);
733 
734 	ssd130x_power_off(ssd130x);
735 }
736 
737 static const struct drm_encoder_helper_funcs ssd130x_encoder_helper_funcs = {
738 	.atomic_enable = ssd130x_encoder_helper_atomic_enable,
739 	.atomic_disable = ssd130x_encoder_helper_atomic_disable,
740 };
741 
742 static const struct drm_encoder_funcs ssd130x_encoder_funcs = {
743 	.destroy = drm_encoder_cleanup,
744 };
745 
746 static int ssd130x_connector_helper_get_modes(struct drm_connector *connector)
747 {
748 	struct ssd130x_device *ssd130x = drm_to_ssd130x(connector->dev);
749 	struct drm_display_mode *mode;
750 	struct device *dev = ssd130x->dev;
751 
752 	mode = drm_mode_duplicate(connector->dev, &ssd130x->mode);
753 	if (!mode) {
754 		dev_err(dev, "Failed to duplicated mode\n");
755 		return 0;
756 	}
757 
758 	drm_mode_probed_add(connector, mode);
759 	drm_set_preferred_mode(connector, mode->hdisplay, mode->vdisplay);
760 
761 	/* There is only a single mode */
762 	return 1;
763 }
764 
765 static const struct drm_connector_helper_funcs ssd130x_connector_helper_funcs = {
766 	.get_modes = ssd130x_connector_helper_get_modes,
767 };
768 
769 static const struct drm_connector_funcs ssd130x_connector_funcs = {
770 	.reset = drm_atomic_helper_connector_reset,
771 	.fill_modes = drm_helper_probe_single_connector_modes,
772 	.destroy = drm_connector_cleanup,
773 	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
774 	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
775 };
776 
777 static const struct drm_mode_config_funcs ssd130x_mode_config_funcs = {
778 	.fb_create = drm_gem_fb_create_with_dirty,
779 	.atomic_check = drm_atomic_helper_check,
780 	.atomic_commit = drm_atomic_helper_commit,
781 };
782 
783 static const uint32_t ssd130x_formats[] = {
784 	DRM_FORMAT_XRGB8888,
785 };
786 
787 DEFINE_DRM_GEM_FOPS(ssd130x_fops);
788 
789 static const struct drm_driver ssd130x_drm_driver = {
790 	DRM_GEM_SHMEM_DRIVER_OPS,
791 	.name			= DRIVER_NAME,
792 	.desc			= DRIVER_DESC,
793 	.date			= DRIVER_DATE,
794 	.major			= DRIVER_MAJOR,
795 	.minor			= DRIVER_MINOR,
796 	.driver_features	= DRIVER_ATOMIC | DRIVER_GEM | DRIVER_MODESET,
797 	.fops			= &ssd130x_fops,
798 };
799 
800 static int ssd130x_update_bl(struct backlight_device *bdev)
801 {
802 	struct ssd130x_device *ssd130x = bl_get_data(bdev);
803 	int brightness = backlight_get_brightness(bdev);
804 	int ret;
805 
806 	ssd130x->contrast = brightness;
807 
808 	ret = ssd130x_write_cmd(ssd130x, 1, SSD130X_CONTRAST);
809 	if (ret < 0)
810 		return ret;
811 
812 	ret = ssd130x_write_cmd(ssd130x, 1, ssd130x->contrast);
813 	if (ret < 0)
814 		return ret;
815 
816 	return 0;
817 }
818 
819 static const struct backlight_ops ssd130xfb_bl_ops = {
820 	.update_status	= ssd130x_update_bl,
821 };
822 
823 static void ssd130x_parse_properties(struct ssd130x_device *ssd130x)
824 {
825 	struct device *dev = ssd130x->dev;
826 
827 	if (device_property_read_u32(dev, "solomon,width", &ssd130x->width))
828 		ssd130x->width = ssd130x->device_info->default_width;
829 
830 	if (device_property_read_u32(dev, "solomon,height", &ssd130x->height))
831 		ssd130x->height = ssd130x->device_info->default_height;
832 
833 	if (device_property_read_u32(dev, "solomon,page-offset", &ssd130x->page_offset))
834 		ssd130x->page_offset = 1;
835 
836 	if (device_property_read_u32(dev, "solomon,col-offset", &ssd130x->col_offset))
837 		ssd130x->col_offset = 0;
838 
839 	if (device_property_read_u32(dev, "solomon,com-offset", &ssd130x->com_offset))
840 		ssd130x->com_offset = 0;
841 
842 	if (device_property_read_u32(dev, "solomon,prechargep1", &ssd130x->prechargep1))
843 		ssd130x->prechargep1 = 2;
844 
845 	if (device_property_read_u32(dev, "solomon,prechargep2", &ssd130x->prechargep2))
846 		ssd130x->prechargep2 = 2;
847 
848 	if (!device_property_read_u8_array(dev, "solomon,lookup-table",
849 					   ssd130x->lookup_table,
850 					   ARRAY_SIZE(ssd130x->lookup_table)))
851 		ssd130x->lookup_table_set = 1;
852 
853 	ssd130x->seg_remap = !device_property_read_bool(dev, "solomon,segment-no-remap");
854 	ssd130x->com_seq = device_property_read_bool(dev, "solomon,com-seq");
855 	ssd130x->com_lrremap = device_property_read_bool(dev, "solomon,com-lrremap");
856 	ssd130x->com_invdir = device_property_read_bool(dev, "solomon,com-invdir");
857 	ssd130x->area_color_enable =
858 		device_property_read_bool(dev, "solomon,area-color-enable");
859 	ssd130x->low_power = device_property_read_bool(dev, "solomon,low-power");
860 
861 	ssd130x->contrast = 127;
862 	ssd130x->vcomh = ssd130x->device_info->default_vcomh;
863 
864 	/* Setup display timing */
865 	if (device_property_read_u32(dev, "solomon,dclk-div", &ssd130x->dclk_div))
866 		ssd130x->dclk_div = ssd130x->device_info->default_dclk_div;
867 	if (device_property_read_u32(dev, "solomon,dclk-frq", &ssd130x->dclk_frq))
868 		ssd130x->dclk_frq = ssd130x->device_info->default_dclk_frq;
869 }
870 
871 static int ssd130x_init_modeset(struct ssd130x_device *ssd130x)
872 {
873 	struct drm_display_mode *mode = &ssd130x->mode;
874 	struct device *dev = ssd130x->dev;
875 	struct drm_device *drm = &ssd130x->drm;
876 	unsigned long max_width, max_height;
877 	struct drm_plane *primary_plane;
878 	struct drm_crtc *crtc;
879 	struct drm_encoder *encoder;
880 	struct drm_connector *connector;
881 	int ret;
882 
883 	/*
884 	 * Modesetting
885 	 */
886 
887 	ret = drmm_mode_config_init(drm);
888 	if (ret) {
889 		dev_err(dev, "DRM mode config init failed: %d\n", ret);
890 		return ret;
891 	}
892 
893 	mode->type = DRM_MODE_TYPE_DRIVER;
894 	mode->clock = 1;
895 	mode->hdisplay = mode->htotal = ssd130x->width;
896 	mode->hsync_start = mode->hsync_end = ssd130x->width;
897 	mode->vdisplay = mode->vtotal = ssd130x->height;
898 	mode->vsync_start = mode->vsync_end = ssd130x->height;
899 	mode->width_mm = 27;
900 	mode->height_mm = 27;
901 
902 	max_width = max_t(unsigned long, mode->hdisplay, DRM_SHADOW_PLANE_MAX_WIDTH);
903 	max_height = max_t(unsigned long, mode->vdisplay, DRM_SHADOW_PLANE_MAX_HEIGHT);
904 
905 	drm->mode_config.min_width = mode->hdisplay;
906 	drm->mode_config.max_width = max_width;
907 	drm->mode_config.min_height = mode->vdisplay;
908 	drm->mode_config.max_height = max_height;
909 	drm->mode_config.preferred_depth = 24;
910 	drm->mode_config.funcs = &ssd130x_mode_config_funcs;
911 
912 	/* Primary plane */
913 
914 	primary_plane = &ssd130x->primary_plane;
915 	ret = drm_universal_plane_init(drm, primary_plane, 0, &ssd130x_primary_plane_funcs,
916 				       ssd130x_formats, ARRAY_SIZE(ssd130x_formats),
917 				       NULL, DRM_PLANE_TYPE_PRIMARY, NULL);
918 	if (ret) {
919 		dev_err(dev, "DRM primary plane init failed: %d\n", ret);
920 		return ret;
921 	}
922 
923 	drm_plane_helper_add(primary_plane, &ssd130x_primary_plane_helper_funcs);
924 
925 	drm_plane_enable_fb_damage_clips(primary_plane);
926 
927 	/* CRTC */
928 
929 	crtc = &ssd130x->crtc;
930 	ret = drm_crtc_init_with_planes(drm, crtc, primary_plane, NULL,
931 					&ssd130x_crtc_funcs, NULL);
932 	if (ret) {
933 		dev_err(dev, "DRM crtc init failed: %d\n", ret);
934 		return ret;
935 	}
936 
937 	drm_crtc_helper_add(crtc, &ssd130x_crtc_helper_funcs);
938 
939 	/* Encoder */
940 
941 	encoder = &ssd130x->encoder;
942 	ret = drm_encoder_init(drm, encoder, &ssd130x_encoder_funcs,
943 			       DRM_MODE_ENCODER_NONE, NULL);
944 	if (ret) {
945 		dev_err(dev, "DRM encoder init failed: %d\n", ret);
946 		return ret;
947 	}
948 
949 	drm_encoder_helper_add(encoder, &ssd130x_encoder_helper_funcs);
950 
951 	encoder->possible_crtcs = drm_crtc_mask(crtc);
952 
953 	/* Connector */
954 
955 	connector = &ssd130x->connector;
956 	ret = drm_connector_init(drm, connector, &ssd130x_connector_funcs,
957 				 DRM_MODE_CONNECTOR_Unknown);
958 	if (ret) {
959 		dev_err(dev, "DRM connector init failed: %d\n", ret);
960 		return ret;
961 	}
962 
963 	drm_connector_helper_add(connector, &ssd130x_connector_helper_funcs);
964 
965 	ret = drm_connector_attach_encoder(connector, encoder);
966 	if (ret) {
967 		dev_err(dev, "DRM attach connector to encoder failed: %d\n", ret);
968 		return ret;
969 	}
970 
971 	drm_mode_config_reset(drm);
972 
973 	return 0;
974 }
975 
976 static int ssd130x_get_resources(struct ssd130x_device *ssd130x)
977 {
978 	struct device *dev = ssd130x->dev;
979 
980 	ssd130x->reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
981 	if (IS_ERR(ssd130x->reset))
982 		return dev_err_probe(dev, PTR_ERR(ssd130x->reset),
983 				     "Failed to get reset gpio\n");
984 
985 	ssd130x->vcc_reg = devm_regulator_get(dev, "vcc");
986 	if (IS_ERR(ssd130x->vcc_reg))
987 		return dev_err_probe(dev, PTR_ERR(ssd130x->vcc_reg),
988 				     "Failed to get VCC regulator\n");
989 
990 	return 0;
991 }
992 
993 struct ssd130x_device *ssd130x_probe(struct device *dev, struct regmap *regmap)
994 {
995 	struct ssd130x_device *ssd130x;
996 	struct backlight_device *bl;
997 	struct drm_device *drm;
998 	int ret;
999 
1000 	ssd130x = devm_drm_dev_alloc(dev, &ssd130x_drm_driver,
1001 				     struct ssd130x_device, drm);
1002 	if (IS_ERR(ssd130x))
1003 		return ERR_PTR(dev_err_probe(dev, PTR_ERR(ssd130x),
1004 					     "Failed to allocate DRM device\n"));
1005 
1006 	drm = &ssd130x->drm;
1007 
1008 	ssd130x->dev = dev;
1009 	ssd130x->regmap = regmap;
1010 	ssd130x->device_info = device_get_match_data(dev);
1011 
1012 	if (ssd130x->device_info->page_mode_only)
1013 		ssd130x->page_address_mode = 1;
1014 
1015 	ssd130x_parse_properties(ssd130x);
1016 
1017 	ret = ssd130x_get_resources(ssd130x);
1018 	if (ret)
1019 		return ERR_PTR(ret);
1020 
1021 	bl = devm_backlight_device_register(dev, dev_name(dev), dev, ssd130x,
1022 					    &ssd130xfb_bl_ops, NULL);
1023 	if (IS_ERR(bl))
1024 		return ERR_PTR(dev_err_probe(dev, PTR_ERR(bl),
1025 					     "Unable to register backlight device\n"));
1026 
1027 	bl->props.brightness = ssd130x->contrast;
1028 	bl->props.max_brightness = MAX_CONTRAST;
1029 	ssd130x->bl_dev = bl;
1030 
1031 	ret = ssd130x_init_modeset(ssd130x);
1032 	if (ret)
1033 		return ERR_PTR(ret);
1034 
1035 	ret = drm_dev_register(drm, 0);
1036 	if (ret)
1037 		return ERR_PTR(dev_err_probe(dev, ret, "DRM device register failed\n"));
1038 
1039 	drm_fbdev_generic_setup(drm, 32);
1040 
1041 	return ssd130x;
1042 }
1043 EXPORT_SYMBOL_GPL(ssd130x_probe);
1044 
1045 void ssd130x_remove(struct ssd130x_device *ssd130x)
1046 {
1047 	drm_dev_unplug(&ssd130x->drm);
1048 }
1049 EXPORT_SYMBOL_GPL(ssd130x_remove);
1050 
1051 void ssd130x_shutdown(struct ssd130x_device *ssd130x)
1052 {
1053 	drm_atomic_helper_shutdown(&ssd130x->drm);
1054 }
1055 EXPORT_SYMBOL_GPL(ssd130x_shutdown);
1056 
1057 MODULE_DESCRIPTION(DRIVER_DESC);
1058 MODULE_AUTHOR("Javier Martinez Canillas <javierm@redhat.com>");
1059 MODULE_LICENSE("GPL v2");
1060