xref: /openbmc/linux/drivers/gpu/drm/solomon/ssd130x.c (revision 49d7d581ceaf4cf85443868b825d45903b4b634c)
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 static int ssd130x_buf_alloc(struct ssd130x_device *ssd130x)
150 {
151 	unsigned int page_height = ssd130x->device_info->page_height;
152 	unsigned int pages = DIV_ROUND_UP(ssd130x->height, page_height);
153 
154 	ssd130x->buffer = kcalloc(DIV_ROUND_UP(ssd130x->width, 8),
155 				  ssd130x->height, GFP_KERNEL);
156 	if (!ssd130x->buffer)
157 		return -ENOMEM;
158 
159 	ssd130x->data_array = kcalloc(ssd130x->width, pages, GFP_KERNEL);
160 	if (!ssd130x->data_array) {
161 		kfree(ssd130x->buffer);
162 		return -ENOMEM;
163 	}
164 
165 	return 0;
166 }
167 
168 static void ssd130x_buf_free(struct ssd130x_device *ssd130x)
169 {
170 	kfree(ssd130x->data_array);
171 	kfree(ssd130x->buffer);
172 }
173 
174 /*
175  * Helper to write data (SSD130X_DATA) to the device.
176  */
177 static int ssd130x_write_data(struct ssd130x_device *ssd130x, u8 *values, int count)
178 {
179 	return regmap_bulk_write(ssd130x->regmap, SSD130X_DATA, values, count);
180 }
181 
182 /*
183  * Helper to write command (SSD130X_COMMAND). The fist variadic argument
184  * is the command to write and the following are the command options.
185  *
186  * Note that the ssd130x protocol requires each command and option to be
187  * written as a SSD130X_COMMAND device register value. That is why a call
188  * to regmap_write(..., SSD130X_COMMAND, ...) is done for each argument.
189  */
190 static int ssd130x_write_cmd(struct ssd130x_device *ssd130x, int count,
191 			     /* u8 cmd, u8 option, ... */...)
192 {
193 	va_list ap;
194 	u8 value;
195 	int ret;
196 
197 	va_start(ap, count);
198 
199 	do {
200 		value = va_arg(ap, int);
201 		ret = regmap_write(ssd130x->regmap, SSD130X_COMMAND, value);
202 		if (ret)
203 			goto out_end;
204 	} while (--count);
205 
206 out_end:
207 	va_end(ap);
208 
209 	return ret;
210 }
211 
212 /* Set address range for horizontal/vertical addressing modes */
213 static int ssd130x_set_col_range(struct ssd130x_device *ssd130x,
214 				 u8 col_start, u8 cols)
215 {
216 	u8 col_end = col_start + cols - 1;
217 	int ret;
218 
219 	if (col_start == ssd130x->col_start && col_end == ssd130x->col_end)
220 		return 0;
221 
222 	ret = ssd130x_write_cmd(ssd130x, 3, SSD130X_SET_COL_RANGE, col_start, col_end);
223 	if (ret < 0)
224 		return ret;
225 
226 	ssd130x->col_start = col_start;
227 	ssd130x->col_end = col_end;
228 	return 0;
229 }
230 
231 static int ssd130x_set_page_range(struct ssd130x_device *ssd130x,
232 				  u8 page_start, u8 pages)
233 {
234 	u8 page_end = page_start + pages - 1;
235 	int ret;
236 
237 	if (page_start == ssd130x->page_start && page_end == ssd130x->page_end)
238 		return 0;
239 
240 	ret = ssd130x_write_cmd(ssd130x, 3, SSD130X_SET_PAGE_RANGE, page_start, page_end);
241 	if (ret < 0)
242 		return ret;
243 
244 	ssd130x->page_start = page_start;
245 	ssd130x->page_end = page_end;
246 	return 0;
247 }
248 
249 /* Set page and column start address for page addressing mode */
250 static int ssd130x_set_page_pos(struct ssd130x_device *ssd130x,
251 				u8 page_start, u8 col_start)
252 {
253 	int ret;
254 	u32 page, col_low, col_high;
255 
256 	page = SSD130X_START_PAGE_ADDRESS |
257 	       SSD130X_START_PAGE_ADDRESS_SET(page_start);
258 	col_low = SSD130X_PAGE_COL_START_LOW |
259 		  SSD130X_PAGE_COL_START_LOW_SET(col_start);
260 	col_high = SSD130X_PAGE_COL_START_HIGH |
261 		   SSD130X_PAGE_COL_START_HIGH_SET(col_start);
262 	ret = ssd130x_write_cmd(ssd130x, 3, page, col_low, col_high);
263 	if (ret < 0)
264 		return ret;
265 
266 	return 0;
267 }
268 
269 static int ssd130x_pwm_enable(struct ssd130x_device *ssd130x)
270 {
271 	struct device *dev = ssd130x->dev;
272 	struct pwm_state pwmstate;
273 
274 	ssd130x->pwm = pwm_get(dev, NULL);
275 	if (IS_ERR(ssd130x->pwm)) {
276 		dev_err(dev, "Could not get PWM from firmware description!\n");
277 		return PTR_ERR(ssd130x->pwm);
278 	}
279 
280 	pwm_init_state(ssd130x->pwm, &pwmstate);
281 	pwm_set_relative_duty_cycle(&pwmstate, 50, 100);
282 	pwm_apply_state(ssd130x->pwm, &pwmstate);
283 
284 	/* Enable the PWM */
285 	pwm_enable(ssd130x->pwm);
286 
287 	dev_dbg(dev, "Using PWM%d with a %lluns period.\n",
288 		ssd130x->pwm->pwm, pwm_get_period(ssd130x->pwm));
289 
290 	return 0;
291 }
292 
293 static void ssd130x_reset(struct ssd130x_device *ssd130x)
294 {
295 	if (!ssd130x->reset)
296 		return;
297 
298 	/* Reset the screen */
299 	gpiod_set_value_cansleep(ssd130x->reset, 1);
300 	udelay(4);
301 	gpiod_set_value_cansleep(ssd130x->reset, 0);
302 	udelay(4);
303 }
304 
305 static int ssd130x_power_on(struct ssd130x_device *ssd130x)
306 {
307 	struct device *dev = ssd130x->dev;
308 	int ret;
309 
310 	ssd130x_reset(ssd130x);
311 
312 	ret = regulator_enable(ssd130x->vcc_reg);
313 	if (ret) {
314 		dev_err(dev, "Failed to enable VCC: %d\n", ret);
315 		return ret;
316 	}
317 
318 	if (ssd130x->device_info->need_pwm) {
319 		ret = ssd130x_pwm_enable(ssd130x);
320 		if (ret) {
321 			dev_err(dev, "Failed to enable PWM: %d\n", ret);
322 			regulator_disable(ssd130x->vcc_reg);
323 			return ret;
324 		}
325 	}
326 
327 	return 0;
328 }
329 
330 static void ssd130x_power_off(struct ssd130x_device *ssd130x)
331 {
332 	pwm_disable(ssd130x->pwm);
333 	pwm_put(ssd130x->pwm);
334 
335 	regulator_disable(ssd130x->vcc_reg);
336 }
337 
338 static int ssd130x_init(struct ssd130x_device *ssd130x)
339 {
340 	u32 precharge, dclk, com_invdir, compins, chargepump, seg_remap;
341 	bool scan_mode;
342 	int ret;
343 
344 	/* Set initial contrast */
345 	ret = ssd130x_write_cmd(ssd130x, 2, SSD130X_CONTRAST, ssd130x->contrast);
346 	if (ret < 0)
347 		return ret;
348 
349 	/* Set segment re-map */
350 	seg_remap = (SSD130X_SET_SEG_REMAP |
351 		     SSD130X_SET_SEG_REMAP_SET(ssd130x->seg_remap));
352 	ret = ssd130x_write_cmd(ssd130x, 1, seg_remap);
353 	if (ret < 0)
354 		return ret;
355 
356 	/* Set COM direction */
357 	com_invdir = (SSD130X_SET_COM_SCAN_DIR |
358 		      SSD130X_SET_COM_SCAN_DIR_SET(ssd130x->com_invdir));
359 	ret = ssd130x_write_cmd(ssd130x,  1, com_invdir);
360 	if (ret < 0)
361 		return ret;
362 
363 	/* Set multiplex ratio value */
364 	ret = ssd130x_write_cmd(ssd130x, 2, SSD130X_SET_MULTIPLEX_RATIO, ssd130x->height - 1);
365 	if (ret < 0)
366 		return ret;
367 
368 	/* set display offset value */
369 	ret = ssd130x_write_cmd(ssd130x, 2, SSD130X_SET_DISPLAY_OFFSET, ssd130x->com_offset);
370 	if (ret < 0)
371 		return ret;
372 
373 	/* Set clock frequency */
374 	dclk = (SSD130X_SET_CLOCK_DIV_SET(ssd130x->dclk_div - 1) |
375 		SSD130X_SET_CLOCK_FREQ_SET(ssd130x->dclk_frq));
376 	ret = ssd130x_write_cmd(ssd130x, 2, SSD130X_SET_CLOCK_FREQ, dclk);
377 	if (ret < 0)
378 		return ret;
379 
380 	/* Set Area Color Mode ON/OFF & Low Power Display Mode */
381 	if (ssd130x->area_color_enable || ssd130x->low_power) {
382 		u32 mode = 0;
383 
384 		if (ssd130x->area_color_enable)
385 			mode |= SSD130X_SET_AREA_COLOR_MODE_ENABLE;
386 
387 		if (ssd130x->low_power)
388 			mode |= SSD130X_SET_AREA_COLOR_MODE_LOW_POWER;
389 
390 		ret = ssd130x_write_cmd(ssd130x, 2, SSD130X_SET_AREA_COLOR_MODE, mode);
391 		if (ret < 0)
392 			return ret;
393 	}
394 
395 	/* Set precharge period in number of ticks from the internal clock */
396 	precharge = (SSD130X_SET_PRECHARGE_PERIOD1_SET(ssd130x->prechargep1) |
397 		     SSD130X_SET_PRECHARGE_PERIOD2_SET(ssd130x->prechargep2));
398 	ret = ssd130x_write_cmd(ssd130x, 2, SSD130X_SET_PRECHARGE_PERIOD, precharge);
399 	if (ret < 0)
400 		return ret;
401 
402 	/* Set COM pins configuration */
403 	compins = BIT(1);
404 	/*
405 	 * The COM scan mode field values are the inverse of the boolean DT
406 	 * property "solomon,com-seq". The value 0b means scan from COM0 to
407 	 * COM[N - 1] while 1b means scan from COM[N - 1] to COM0.
408 	 */
409 	scan_mode = !ssd130x->com_seq;
410 	compins |= (SSD130X_SET_COM_PINS_CONFIG1_SET(scan_mode) |
411 		    SSD130X_SET_COM_PINS_CONFIG2_SET(ssd130x->com_lrremap));
412 	ret = ssd130x_write_cmd(ssd130x, 2, SSD130X_SET_COM_PINS_CONFIG, compins);
413 	if (ret < 0)
414 		return ret;
415 
416 	/* Set VCOMH */
417 	ret = ssd130x_write_cmd(ssd130x, 2, SSD130X_SET_VCOMH, ssd130x->vcomh);
418 	if (ret < 0)
419 		return ret;
420 
421 	/* Turn on the DC-DC Charge Pump */
422 	chargepump = BIT(4);
423 
424 	if (ssd130x->device_info->need_chargepump)
425 		chargepump |= BIT(2);
426 
427 	ret = ssd130x_write_cmd(ssd130x, 2, SSD130X_CHARGE_PUMP, chargepump);
428 	if (ret < 0)
429 		return ret;
430 
431 	/* Set lookup table */
432 	if (ssd130x->lookup_table_set) {
433 		int i;
434 
435 		ret = ssd130x_write_cmd(ssd130x, 1, SSD130X_SET_LOOKUP_TABLE);
436 		if (ret < 0)
437 			return ret;
438 
439 		for (i = 0; i < ARRAY_SIZE(ssd130x->lookup_table); i++) {
440 			u8 val = ssd130x->lookup_table[i];
441 
442 			if (val < 31 || val > 63)
443 				dev_warn(ssd130x->dev,
444 					 "lookup table index %d value out of range 31 <= %d <= 63\n",
445 					 i, val);
446 			ret = ssd130x_write_cmd(ssd130x, 1, val);
447 			if (ret < 0)
448 				return ret;
449 		}
450 	}
451 
452 	/* Switch to page addressing mode */
453 	if (ssd130x->page_address_mode)
454 		return ssd130x_write_cmd(ssd130x, 2, SSD130X_SET_ADDRESS_MODE,
455 					 SSD130X_SET_ADDRESS_MODE_PAGE);
456 
457 	/* Switch to horizontal addressing mode */
458 	return ssd130x_write_cmd(ssd130x, 2, SSD130X_SET_ADDRESS_MODE,
459 				 SSD130X_SET_ADDRESS_MODE_HORIZONTAL);
460 }
461 
462 static int ssd130x_update_rect(struct ssd130x_device *ssd130x, struct drm_rect *rect)
463 {
464 	unsigned int x = rect->x1;
465 	unsigned int y = rect->y1;
466 	u8 *buf = ssd130x->buffer;
467 	u8 *data_array = ssd130x->data_array;
468 	unsigned int width = drm_rect_width(rect);
469 	unsigned int height = drm_rect_height(rect);
470 	unsigned int line_length = DIV_ROUND_UP(width, 8);
471 	unsigned int page_height = ssd130x->device_info->page_height;
472 	unsigned int pages = DIV_ROUND_UP(height, page_height);
473 	struct drm_device *drm = &ssd130x->drm;
474 	u32 array_idx = 0;
475 	int ret, i, j, k;
476 
477 	drm_WARN_ONCE(drm, y % 8 != 0, "y must be aligned to screen page\n");
478 
479 	/*
480 	 * The screen is divided in pages, each having a height of 8
481 	 * pixels, and the width of the screen. When sending a byte of
482 	 * data to the controller, it gives the 8 bits for the current
483 	 * column. I.e, the first byte are the 8 bits of the first
484 	 * column, then the 8 bits for the second column, etc.
485 	 *
486 	 *
487 	 * Representation of the screen, assuming it is 5 bits
488 	 * wide. Each letter-number combination is a bit that controls
489 	 * one pixel.
490 	 *
491 	 * A0 A1 A2 A3 A4
492 	 * B0 B1 B2 B3 B4
493 	 * C0 C1 C2 C3 C4
494 	 * D0 D1 D2 D3 D4
495 	 * E0 E1 E2 E3 E4
496 	 * F0 F1 F2 F3 F4
497 	 * G0 G1 G2 G3 G4
498 	 * H0 H1 H2 H3 H4
499 	 *
500 	 * If you want to update this screen, you need to send 5 bytes:
501 	 *  (1) A0 B0 C0 D0 E0 F0 G0 H0
502 	 *  (2) A1 B1 C1 D1 E1 F1 G1 H1
503 	 *  (3) A2 B2 C2 D2 E2 F2 G2 H2
504 	 *  (4) A3 B3 C3 D3 E3 F3 G3 H3
505 	 *  (5) A4 B4 C4 D4 E4 F4 G4 H4
506 	 */
507 
508 	if (!ssd130x->page_address_mode) {
509 		/* Set address range for horizontal addressing mode */
510 		ret = ssd130x_set_col_range(ssd130x, ssd130x->col_offset + x, width);
511 		if (ret < 0)
512 			return ret;
513 
514 		ret = ssd130x_set_page_range(ssd130x, ssd130x->page_offset + y / 8, pages);
515 		if (ret < 0)
516 			return ret;
517 	}
518 
519 	for (i = 0; i < pages; i++) {
520 		int m = 8;
521 
522 		/* Last page may be partial */
523 		if (8 * (y / 8 + i + 1) > ssd130x->height)
524 			m = ssd130x->height % 8;
525 		for (j = 0; j < width; j++) {
526 			u8 data = 0;
527 
528 			for (k = 0; k < m; k++) {
529 				u8 byte = buf[(8 * i + k) * line_length + j / 8];
530 				u8 bit = (byte >> (j % 8)) & 1;
531 
532 				data |= bit << k;
533 			}
534 			data_array[array_idx++] = data;
535 		}
536 
537 		/*
538 		 * In page addressing mode, the start address needs to be reset,
539 		 * and each page then needs to be written out separately.
540 		 */
541 		if (ssd130x->page_address_mode) {
542 			ret = ssd130x_set_page_pos(ssd130x,
543 						   ssd130x->page_offset + i,
544 						   ssd130x->col_offset + x);
545 			if (ret < 0)
546 				return ret;
547 
548 			ret = ssd130x_write_data(ssd130x, data_array, width);
549 			if (ret < 0)
550 				return ret;
551 
552 			array_idx = 0;
553 		}
554 	}
555 
556 	/* Write out update in one go if we aren't using page addressing mode */
557 	if (!ssd130x->page_address_mode)
558 		ret = ssd130x_write_data(ssd130x, data_array, width * pages);
559 
560 	return ret;
561 }
562 
563 static void ssd130x_clear_screen(struct ssd130x_device *ssd130x)
564 {
565 	struct drm_rect fullscreen = {
566 		.x1 = 0,
567 		.x2 = ssd130x->width,
568 		.y1 = 0,
569 		.y2 = ssd130x->height,
570 	};
571 
572 	ssd130x_update_rect(ssd130x, &fullscreen);
573 }
574 
575 static int ssd130x_fb_blit_rect(struct drm_framebuffer *fb, const struct iosys_map *vmap,
576 				struct drm_rect *rect)
577 {
578 	struct ssd130x_device *ssd130x = drm_to_ssd130x(fb->dev);
579 	unsigned int page_height = ssd130x->device_info->page_height;
580 	struct iosys_map dst;
581 	unsigned int dst_pitch;
582 	int ret = 0;
583 	u8 *buf = ssd130x->buffer;
584 
585 	if (!buf)
586 		return 0;
587 
588 	/* Align y to display page boundaries */
589 	rect->y1 = round_down(rect->y1, page_height);
590 	rect->y2 = min_t(unsigned int, round_up(rect->y2, page_height), ssd130x->height);
591 
592 	dst_pitch = DIV_ROUND_UP(drm_rect_width(rect), page_height);
593 
594 	ret = drm_gem_fb_begin_cpu_access(fb, DMA_FROM_DEVICE);
595 	if (ret)
596 		return ret;
597 
598 	iosys_map_set_vaddr(&dst, buf);
599 	drm_fb_xrgb8888_to_mono(&dst, &dst_pitch, vmap, fb, rect);
600 
601 	drm_gem_fb_end_cpu_access(fb, DMA_FROM_DEVICE);
602 
603 	ssd130x_update_rect(ssd130x, rect);
604 
605 	return ret;
606 }
607 
608 static void ssd130x_primary_plane_helper_atomic_update(struct drm_plane *plane,
609 						       struct drm_atomic_state *state)
610 {
611 	struct drm_plane_state *plane_state = drm_atomic_get_new_plane_state(state, plane);
612 	struct drm_plane_state *old_plane_state = drm_atomic_get_old_plane_state(state, plane);
613 	struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(plane_state);
614 	struct drm_atomic_helper_damage_iter iter;
615 	struct drm_device *drm = plane->dev;
616 	struct drm_rect dst_clip;
617 	struct drm_rect damage;
618 	int idx;
619 
620 	if (!drm_dev_enter(drm, &idx))
621 		return;
622 
623 	drm_atomic_helper_damage_iter_init(&iter, old_plane_state, plane_state);
624 	drm_atomic_for_each_plane_damage(&iter, &damage) {
625 		dst_clip = plane_state->dst;
626 
627 		if (!drm_rect_intersect(&dst_clip, &damage))
628 			continue;
629 
630 		ssd130x_fb_blit_rect(plane_state->fb, &shadow_plane_state->data[0], &dst_clip);
631 	}
632 
633 	drm_dev_exit(idx);
634 }
635 
636 static void ssd130x_primary_plane_helper_atomic_disable(struct drm_plane *plane,
637 							struct drm_atomic_state *state)
638 {
639 	struct drm_device *drm = plane->dev;
640 	struct ssd130x_device *ssd130x = drm_to_ssd130x(drm);
641 	int idx;
642 
643 	if (!drm_dev_enter(drm, &idx))
644 		return;
645 
646 	ssd130x_clear_screen(ssd130x);
647 
648 	drm_dev_exit(idx);
649 }
650 
651 static const struct drm_plane_helper_funcs ssd130x_primary_plane_helper_funcs = {
652 	DRM_GEM_SHADOW_PLANE_HELPER_FUNCS,
653 	.atomic_check = drm_plane_helper_atomic_check,
654 	.atomic_update = ssd130x_primary_plane_helper_atomic_update,
655 	.atomic_disable = ssd130x_primary_plane_helper_atomic_disable,
656 };
657 
658 static const struct drm_plane_funcs ssd130x_primary_plane_funcs = {
659 	.update_plane = drm_atomic_helper_update_plane,
660 	.disable_plane = drm_atomic_helper_disable_plane,
661 	.destroy = drm_plane_cleanup,
662 	DRM_GEM_SHADOW_PLANE_FUNCS,
663 };
664 
665 static enum drm_mode_status ssd130x_crtc_helper_mode_valid(struct drm_crtc *crtc,
666 							   const struct drm_display_mode *mode)
667 {
668 	struct ssd130x_device *ssd130x = drm_to_ssd130x(crtc->dev);
669 
670 	if (mode->hdisplay != ssd130x->mode.hdisplay &&
671 	    mode->vdisplay != ssd130x->mode.vdisplay)
672 		return MODE_ONE_SIZE;
673 	else if (mode->hdisplay != ssd130x->mode.hdisplay)
674 		return MODE_ONE_WIDTH;
675 	else if (mode->vdisplay != ssd130x->mode.vdisplay)
676 		return MODE_ONE_HEIGHT;
677 
678 	return MODE_OK;
679 }
680 
681 /*
682  * The CRTC is always enabled. Screen updates are performed by
683  * the primary plane's atomic_update function. Disabling clears
684  * the screen in the primary plane's atomic_disable function.
685  */
686 static const struct drm_crtc_helper_funcs ssd130x_crtc_helper_funcs = {
687 	.mode_valid = ssd130x_crtc_helper_mode_valid,
688 	.atomic_check = drm_crtc_helper_atomic_check,
689 };
690 
691 static const struct drm_crtc_funcs ssd130x_crtc_funcs = {
692 	.reset = drm_atomic_helper_crtc_reset,
693 	.destroy = drm_crtc_cleanup,
694 	.set_config = drm_atomic_helper_set_config,
695 	.page_flip = drm_atomic_helper_page_flip,
696 	.atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
697 	.atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
698 };
699 
700 static void ssd130x_encoder_helper_atomic_enable(struct drm_encoder *encoder,
701 						 struct drm_atomic_state *state)
702 {
703 	struct drm_device *drm = encoder->dev;
704 	struct ssd130x_device *ssd130x = drm_to_ssd130x(drm);
705 	int ret;
706 
707 	ret = ssd130x_power_on(ssd130x);
708 	if (ret)
709 		return;
710 
711 	ret = ssd130x_init(ssd130x);
712 	if (ret)
713 		goto power_off;
714 
715 	ret = ssd130x_buf_alloc(ssd130x);
716 	if (ret)
717 		goto power_off;
718 
719 	ssd130x_write_cmd(ssd130x, 1, SSD130X_DISPLAY_ON);
720 
721 	backlight_enable(ssd130x->bl_dev);
722 
723 	return;
724 
725 power_off:
726 	ssd130x_power_off(ssd130x);
727 	return;
728 }
729 
730 static void ssd130x_encoder_helper_atomic_disable(struct drm_encoder *encoder,
731 						  struct drm_atomic_state *state)
732 {
733 	struct drm_device *drm = encoder->dev;
734 	struct ssd130x_device *ssd130x = drm_to_ssd130x(drm);
735 
736 	backlight_disable(ssd130x->bl_dev);
737 
738 	ssd130x_write_cmd(ssd130x, 1, SSD130X_DISPLAY_OFF);
739 
740 	ssd130x_buf_free(ssd130x);
741 
742 	ssd130x_power_off(ssd130x);
743 }
744 
745 static const struct drm_encoder_helper_funcs ssd130x_encoder_helper_funcs = {
746 	.atomic_enable = ssd130x_encoder_helper_atomic_enable,
747 	.atomic_disable = ssd130x_encoder_helper_atomic_disable,
748 };
749 
750 static const struct drm_encoder_funcs ssd130x_encoder_funcs = {
751 	.destroy = drm_encoder_cleanup,
752 };
753 
754 static int ssd130x_connector_helper_get_modes(struct drm_connector *connector)
755 {
756 	struct ssd130x_device *ssd130x = drm_to_ssd130x(connector->dev);
757 	struct drm_display_mode *mode;
758 	struct device *dev = ssd130x->dev;
759 
760 	mode = drm_mode_duplicate(connector->dev, &ssd130x->mode);
761 	if (!mode) {
762 		dev_err(dev, "Failed to duplicated mode\n");
763 		return 0;
764 	}
765 
766 	drm_mode_probed_add(connector, mode);
767 	drm_set_preferred_mode(connector, mode->hdisplay, mode->vdisplay);
768 
769 	/* There is only a single mode */
770 	return 1;
771 }
772 
773 static const struct drm_connector_helper_funcs ssd130x_connector_helper_funcs = {
774 	.get_modes = ssd130x_connector_helper_get_modes,
775 };
776 
777 static const struct drm_connector_funcs ssd130x_connector_funcs = {
778 	.reset = drm_atomic_helper_connector_reset,
779 	.fill_modes = drm_helper_probe_single_connector_modes,
780 	.destroy = drm_connector_cleanup,
781 	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
782 	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
783 };
784 
785 static const struct drm_mode_config_funcs ssd130x_mode_config_funcs = {
786 	.fb_create = drm_gem_fb_create_with_dirty,
787 	.atomic_check = drm_atomic_helper_check,
788 	.atomic_commit = drm_atomic_helper_commit,
789 };
790 
791 static const uint32_t ssd130x_formats[] = {
792 	DRM_FORMAT_XRGB8888,
793 };
794 
795 DEFINE_DRM_GEM_FOPS(ssd130x_fops);
796 
797 static const struct drm_driver ssd130x_drm_driver = {
798 	DRM_GEM_SHMEM_DRIVER_OPS,
799 	.name			= DRIVER_NAME,
800 	.desc			= DRIVER_DESC,
801 	.date			= DRIVER_DATE,
802 	.major			= DRIVER_MAJOR,
803 	.minor			= DRIVER_MINOR,
804 	.driver_features	= DRIVER_ATOMIC | DRIVER_GEM | DRIVER_MODESET,
805 	.fops			= &ssd130x_fops,
806 };
807 
808 static int ssd130x_update_bl(struct backlight_device *bdev)
809 {
810 	struct ssd130x_device *ssd130x = bl_get_data(bdev);
811 	int brightness = backlight_get_brightness(bdev);
812 	int ret;
813 
814 	ssd130x->contrast = brightness;
815 
816 	ret = ssd130x_write_cmd(ssd130x, 1, SSD130X_CONTRAST);
817 	if (ret < 0)
818 		return ret;
819 
820 	ret = ssd130x_write_cmd(ssd130x, 1, ssd130x->contrast);
821 	if (ret < 0)
822 		return ret;
823 
824 	return 0;
825 }
826 
827 static const struct backlight_ops ssd130xfb_bl_ops = {
828 	.update_status	= ssd130x_update_bl,
829 };
830 
831 static void ssd130x_parse_properties(struct ssd130x_device *ssd130x)
832 {
833 	struct device *dev = ssd130x->dev;
834 
835 	if (device_property_read_u32(dev, "solomon,width", &ssd130x->width))
836 		ssd130x->width = ssd130x->device_info->default_width;
837 
838 	if (device_property_read_u32(dev, "solomon,height", &ssd130x->height))
839 		ssd130x->height = ssd130x->device_info->default_height;
840 
841 	if (device_property_read_u32(dev, "solomon,page-offset", &ssd130x->page_offset))
842 		ssd130x->page_offset = 1;
843 
844 	if (device_property_read_u32(dev, "solomon,col-offset", &ssd130x->col_offset))
845 		ssd130x->col_offset = 0;
846 
847 	if (device_property_read_u32(dev, "solomon,com-offset", &ssd130x->com_offset))
848 		ssd130x->com_offset = 0;
849 
850 	if (device_property_read_u32(dev, "solomon,prechargep1", &ssd130x->prechargep1))
851 		ssd130x->prechargep1 = 2;
852 
853 	if (device_property_read_u32(dev, "solomon,prechargep2", &ssd130x->prechargep2))
854 		ssd130x->prechargep2 = 2;
855 
856 	if (!device_property_read_u8_array(dev, "solomon,lookup-table",
857 					   ssd130x->lookup_table,
858 					   ARRAY_SIZE(ssd130x->lookup_table)))
859 		ssd130x->lookup_table_set = 1;
860 
861 	ssd130x->seg_remap = !device_property_read_bool(dev, "solomon,segment-no-remap");
862 	ssd130x->com_seq = device_property_read_bool(dev, "solomon,com-seq");
863 	ssd130x->com_lrremap = device_property_read_bool(dev, "solomon,com-lrremap");
864 	ssd130x->com_invdir = device_property_read_bool(dev, "solomon,com-invdir");
865 	ssd130x->area_color_enable =
866 		device_property_read_bool(dev, "solomon,area-color-enable");
867 	ssd130x->low_power = device_property_read_bool(dev, "solomon,low-power");
868 
869 	ssd130x->contrast = 127;
870 	ssd130x->vcomh = ssd130x->device_info->default_vcomh;
871 
872 	/* Setup display timing */
873 	if (device_property_read_u32(dev, "solomon,dclk-div", &ssd130x->dclk_div))
874 		ssd130x->dclk_div = ssd130x->device_info->default_dclk_div;
875 	if (device_property_read_u32(dev, "solomon,dclk-frq", &ssd130x->dclk_frq))
876 		ssd130x->dclk_frq = ssd130x->device_info->default_dclk_frq;
877 }
878 
879 static int ssd130x_init_modeset(struct ssd130x_device *ssd130x)
880 {
881 	struct drm_display_mode *mode = &ssd130x->mode;
882 	struct device *dev = ssd130x->dev;
883 	struct drm_device *drm = &ssd130x->drm;
884 	unsigned long max_width, max_height;
885 	struct drm_plane *primary_plane;
886 	struct drm_crtc *crtc;
887 	struct drm_encoder *encoder;
888 	struct drm_connector *connector;
889 	int ret;
890 
891 	/*
892 	 * Modesetting
893 	 */
894 
895 	ret = drmm_mode_config_init(drm);
896 	if (ret) {
897 		dev_err(dev, "DRM mode config init failed: %d\n", ret);
898 		return ret;
899 	}
900 
901 	mode->type = DRM_MODE_TYPE_DRIVER;
902 	mode->clock = 1;
903 	mode->hdisplay = mode->htotal = ssd130x->width;
904 	mode->hsync_start = mode->hsync_end = ssd130x->width;
905 	mode->vdisplay = mode->vtotal = ssd130x->height;
906 	mode->vsync_start = mode->vsync_end = ssd130x->height;
907 	mode->width_mm = 27;
908 	mode->height_mm = 27;
909 
910 	max_width = max_t(unsigned long, mode->hdisplay, DRM_SHADOW_PLANE_MAX_WIDTH);
911 	max_height = max_t(unsigned long, mode->vdisplay, DRM_SHADOW_PLANE_MAX_HEIGHT);
912 
913 	drm->mode_config.min_width = mode->hdisplay;
914 	drm->mode_config.max_width = max_width;
915 	drm->mode_config.min_height = mode->vdisplay;
916 	drm->mode_config.max_height = max_height;
917 	drm->mode_config.preferred_depth = 24;
918 	drm->mode_config.funcs = &ssd130x_mode_config_funcs;
919 
920 	/* Primary plane */
921 
922 	primary_plane = &ssd130x->primary_plane;
923 	ret = drm_universal_plane_init(drm, primary_plane, 0, &ssd130x_primary_plane_funcs,
924 				       ssd130x_formats, ARRAY_SIZE(ssd130x_formats),
925 				       NULL, DRM_PLANE_TYPE_PRIMARY, NULL);
926 	if (ret) {
927 		dev_err(dev, "DRM primary plane init failed: %d\n", ret);
928 		return ret;
929 	}
930 
931 	drm_plane_helper_add(primary_plane, &ssd130x_primary_plane_helper_funcs);
932 
933 	drm_plane_enable_fb_damage_clips(primary_plane);
934 
935 	/* CRTC */
936 
937 	crtc = &ssd130x->crtc;
938 	ret = drm_crtc_init_with_planes(drm, crtc, primary_plane, NULL,
939 					&ssd130x_crtc_funcs, NULL);
940 	if (ret) {
941 		dev_err(dev, "DRM crtc init failed: %d\n", ret);
942 		return ret;
943 	}
944 
945 	drm_crtc_helper_add(crtc, &ssd130x_crtc_helper_funcs);
946 
947 	/* Encoder */
948 
949 	encoder = &ssd130x->encoder;
950 	ret = drm_encoder_init(drm, encoder, &ssd130x_encoder_funcs,
951 			       DRM_MODE_ENCODER_NONE, NULL);
952 	if (ret) {
953 		dev_err(dev, "DRM encoder init failed: %d\n", ret);
954 		return ret;
955 	}
956 
957 	drm_encoder_helper_add(encoder, &ssd130x_encoder_helper_funcs);
958 
959 	encoder->possible_crtcs = drm_crtc_mask(crtc);
960 
961 	/* Connector */
962 
963 	connector = &ssd130x->connector;
964 	ret = drm_connector_init(drm, connector, &ssd130x_connector_funcs,
965 				 DRM_MODE_CONNECTOR_Unknown);
966 	if (ret) {
967 		dev_err(dev, "DRM connector init failed: %d\n", ret);
968 		return ret;
969 	}
970 
971 	drm_connector_helper_add(connector, &ssd130x_connector_helper_funcs);
972 
973 	ret = drm_connector_attach_encoder(connector, encoder);
974 	if (ret) {
975 		dev_err(dev, "DRM attach connector to encoder failed: %d\n", ret);
976 		return ret;
977 	}
978 
979 	drm_mode_config_reset(drm);
980 
981 	return 0;
982 }
983 
984 static int ssd130x_get_resources(struct ssd130x_device *ssd130x)
985 {
986 	struct device *dev = ssd130x->dev;
987 
988 	ssd130x->reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
989 	if (IS_ERR(ssd130x->reset))
990 		return dev_err_probe(dev, PTR_ERR(ssd130x->reset),
991 				     "Failed to get reset gpio\n");
992 
993 	ssd130x->vcc_reg = devm_regulator_get(dev, "vcc");
994 	if (IS_ERR(ssd130x->vcc_reg))
995 		return dev_err_probe(dev, PTR_ERR(ssd130x->vcc_reg),
996 				     "Failed to get VCC regulator\n");
997 
998 	return 0;
999 }
1000 
1001 struct ssd130x_device *ssd130x_probe(struct device *dev, struct regmap *regmap)
1002 {
1003 	struct ssd130x_device *ssd130x;
1004 	struct backlight_device *bl;
1005 	struct drm_device *drm;
1006 	int ret;
1007 
1008 	ssd130x = devm_drm_dev_alloc(dev, &ssd130x_drm_driver,
1009 				     struct ssd130x_device, drm);
1010 	if (IS_ERR(ssd130x))
1011 		return ERR_PTR(dev_err_probe(dev, PTR_ERR(ssd130x),
1012 					     "Failed to allocate DRM device\n"));
1013 
1014 	drm = &ssd130x->drm;
1015 
1016 	ssd130x->dev = dev;
1017 	ssd130x->regmap = regmap;
1018 	ssd130x->device_info = device_get_match_data(dev);
1019 
1020 	if (ssd130x->device_info->page_mode_only)
1021 		ssd130x->page_address_mode = 1;
1022 
1023 	ssd130x_parse_properties(ssd130x);
1024 
1025 	ret = ssd130x_get_resources(ssd130x);
1026 	if (ret)
1027 		return ERR_PTR(ret);
1028 
1029 	bl = devm_backlight_device_register(dev, dev_name(dev), dev, ssd130x,
1030 					    &ssd130xfb_bl_ops, NULL);
1031 	if (IS_ERR(bl))
1032 		return ERR_PTR(dev_err_probe(dev, PTR_ERR(bl),
1033 					     "Unable to register backlight device\n"));
1034 
1035 	bl->props.brightness = ssd130x->contrast;
1036 	bl->props.max_brightness = MAX_CONTRAST;
1037 	ssd130x->bl_dev = bl;
1038 
1039 	ret = ssd130x_init_modeset(ssd130x);
1040 	if (ret)
1041 		return ERR_PTR(ret);
1042 
1043 	ret = drm_dev_register(drm, 0);
1044 	if (ret)
1045 		return ERR_PTR(dev_err_probe(dev, ret, "DRM device register failed\n"));
1046 
1047 	drm_fbdev_generic_setup(drm, 32);
1048 
1049 	return ssd130x;
1050 }
1051 EXPORT_SYMBOL_GPL(ssd130x_probe);
1052 
1053 void ssd130x_remove(struct ssd130x_device *ssd130x)
1054 {
1055 	drm_dev_unplug(&ssd130x->drm);
1056 }
1057 EXPORT_SYMBOL_GPL(ssd130x_remove);
1058 
1059 void ssd130x_shutdown(struct ssd130x_device *ssd130x)
1060 {
1061 	drm_atomic_helper_shutdown(&ssd130x->drm);
1062 }
1063 EXPORT_SYMBOL_GPL(ssd130x_shutdown);
1064 
1065 MODULE_DESCRIPTION(DRIVER_DESC);
1066 MODULE_AUTHOR("Javier Martinez Canillas <javierm@redhat.com>");
1067 MODULE_LICENSE("GPL v2");
1068