xref: /linux/drivers/gpu/drm/solomon/ssd130x.c (revision cbac924200b838cfb8d8b1415113d788089dc50b)
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_helper.h>
22 #include <drm/drm_damage_helper.h>
23 #include <drm/drm_fb_cma_helper.h>
24 #include <drm/drm_fb_helper.h>
25 #include <drm/drm_format_helper.h>
26 #include <drm/drm_gem_atomic_helper.h>
27 #include <drm/drm_gem_framebuffer_helper.h>
28 #include <drm/drm_gem_shmem_helper.h>
29 #include <drm/drm_managed.h>
30 #include <drm/drm_modes.h>
31 #include <drm/drm_rect.h>
32 #include <drm/drm_probe_helper.h>
33 
34 #include "ssd130x.h"
35 
36 #define DRIVER_NAME	"ssd130x"
37 #define DRIVER_DESC	"DRM driver for Solomon SSD130x OLED displays"
38 #define DRIVER_DATE	"20220131"
39 #define DRIVER_MAJOR	1
40 #define DRIVER_MINOR	0
41 
42 #define SSD130X_DATA				0x40
43 #define SSD130X_COMMAND				0x80
44 
45 #define SSD130X_SET_ADDRESS_MODE		0x20
46 #define SSD130X_SET_COL_RANGE			0x21
47 #define SSD130X_SET_PAGE_RANGE			0x22
48 #define SSD130X_CONTRAST			0x81
49 #define SSD130X_SET_LOOKUP_TABLE		0x91
50 #define SSD130X_CHARGE_PUMP			0x8d
51 #define SSD130X_SEG_REMAP_ON			0xa1
52 #define SSD130X_DISPLAY_OFF			0xae
53 #define SSD130X_SET_MULTIPLEX_RATIO		0xa8
54 #define SSD130X_DISPLAY_ON			0xaf
55 #define SSD130X_START_PAGE_ADDRESS		0xb0
56 #define SSD130X_SET_COM_SCAN_DIR		0xc0
57 #define SSD130X_SET_DISPLAY_OFFSET		0xd3
58 #define SSD130X_SET_CLOCK_FREQ			0xd5
59 #define SSD130X_SET_AREA_COLOR_MODE		0xd8
60 #define SSD130X_SET_PRECHARGE_PERIOD		0xd9
61 #define SSD130X_SET_COM_PINS_CONFIG		0xda
62 #define SSD130X_SET_VCOMH			0xdb
63 
64 #define SSD130X_SET_COM_SCAN_DIR_MASK		GENMASK(3, 2)
65 #define SSD130X_SET_COM_SCAN_DIR_SET(val)	FIELD_PREP(SSD130X_SET_COM_SCAN_DIR_MASK, (val))
66 #define SSD130X_SET_CLOCK_DIV_MASK		GENMASK(3, 0)
67 #define SSD130X_SET_CLOCK_DIV_SET(val)		FIELD_PREP(SSD130X_SET_CLOCK_DIV_MASK, (val))
68 #define SSD130X_SET_CLOCK_FREQ_MASK		GENMASK(7, 4)
69 #define SSD130X_SET_CLOCK_FREQ_SET(val)		FIELD_PREP(SSD130X_SET_CLOCK_FREQ_MASK, (val))
70 #define SSD130X_SET_PRECHARGE_PERIOD1_MASK	GENMASK(3, 0)
71 #define SSD130X_SET_PRECHARGE_PERIOD1_SET(val)	FIELD_PREP(SSD130X_SET_PRECHARGE_PERIOD1_MASK, (val))
72 #define SSD130X_SET_PRECHARGE_PERIOD2_MASK	GENMASK(7, 4)
73 #define SSD130X_SET_PRECHARGE_PERIOD2_SET(val)	FIELD_PREP(SSD130X_SET_PRECHARGE_PERIOD2_MASK, (val))
74 #define SSD130X_SET_COM_PINS_CONFIG1_MASK	GENMASK(4, 4)
75 #define SSD130X_SET_COM_PINS_CONFIG1_SET(val)	FIELD_PREP(SSD130X_SET_COM_PINS_CONFIG1_MASK, !(val))
76 #define SSD130X_SET_COM_PINS_CONFIG2_MASK	GENMASK(5, 5)
77 #define SSD130X_SET_COM_PINS_CONFIG2_SET(val)	FIELD_PREP(SSD130X_SET_COM_PINS_CONFIG2_MASK, (val))
78 
79 #define SSD130X_SET_ADDRESS_MODE_HORIZONTAL	0x00
80 #define SSD130X_SET_ADDRESS_MODE_VERTICAL	0x01
81 #define SSD130X_SET_ADDRESS_MODE_PAGE		0x02
82 
83 #define SSD130X_SET_AREA_COLOR_MODE_ENABLE	0x1e
84 #define SSD130X_SET_AREA_COLOR_MODE_LOW_POWER	0x05
85 
86 #define MAX_CONTRAST 255
87 
88 static inline struct ssd130x_device *drm_to_ssd130x(struct drm_device *drm)
89 {
90 	return container_of(drm, struct ssd130x_device, drm);
91 }
92 
93 /*
94  * Helper to write data (SSD130X_DATA) to the device.
95  */
96 static int ssd130x_write_data(struct ssd130x_device *ssd130x, u8 *values, int count)
97 {
98 	return regmap_bulk_write(ssd130x->regmap, SSD130X_DATA, values, count);
99 }
100 
101 /*
102  * Helper to write command (SSD130X_COMMAND). The fist variadic argument
103  * is the command to write and the following are the command options.
104  *
105  * Note that the ssd130x protocol requires each command and option to be
106  * written as a SSD130X_COMMAND device register value. That is why a call
107  * to regmap_write(..., SSD130X_COMMAND, ...) is done for each argument.
108  */
109 static int ssd130x_write_cmd(struct ssd130x_device *ssd130x, int count,
110 			     /* u8 cmd, u8 option, ... */...)
111 {
112 	va_list ap;
113 	u8 value;
114 	int ret;
115 
116 	va_start(ap, count);
117 
118 	do {
119 		value = va_arg(ap, int);
120 		ret = regmap_write(ssd130x->regmap, SSD130X_COMMAND, value);
121 		if (ret)
122 			goto out_end;
123 	} while (--count);
124 
125 out_end:
126 	va_end(ap);
127 
128 	return ret;
129 }
130 
131 static int ssd130x_set_col_range(struct ssd130x_device *ssd130x,
132 				 u8 col_start, u8 cols)
133 {
134 	u8 col_end = col_start + cols - 1;
135 	int ret;
136 
137 	if (col_start == ssd130x->col_start && col_end == ssd130x->col_end)
138 		return 0;
139 
140 	ret = ssd130x_write_cmd(ssd130x, 3, SSD130X_SET_COL_RANGE, col_start, col_end);
141 	if (ret < 0)
142 		return ret;
143 
144 	ssd130x->col_start = col_start;
145 	ssd130x->col_end = col_end;
146 	return 0;
147 }
148 
149 static int ssd130x_set_page_range(struct ssd130x_device *ssd130x,
150 				  u8 page_start, u8 pages)
151 {
152 	u8 page_end = page_start + pages - 1;
153 	int ret;
154 
155 	if (page_start == ssd130x->page_start && page_end == ssd130x->page_end)
156 		return 0;
157 
158 	ret = ssd130x_write_cmd(ssd130x, 3, SSD130X_SET_PAGE_RANGE, page_start, page_end);
159 	if (ret < 0)
160 		return ret;
161 
162 	ssd130x->page_start = page_start;
163 	ssd130x->page_end = page_end;
164 	return 0;
165 }
166 
167 static int ssd130x_pwm_enable(struct ssd130x_device *ssd130x)
168 {
169 	struct device *dev = ssd130x->dev;
170 	struct pwm_state pwmstate;
171 
172 	ssd130x->pwm = pwm_get(dev, NULL);
173 	if (IS_ERR(ssd130x->pwm)) {
174 		dev_err(dev, "Could not get PWM from firmware description!\n");
175 		return PTR_ERR(ssd130x->pwm);
176 	}
177 
178 	pwm_init_state(ssd130x->pwm, &pwmstate);
179 	pwm_set_relative_duty_cycle(&pwmstate, 50, 100);
180 	pwm_apply_state(ssd130x->pwm, &pwmstate);
181 
182 	/* Enable the PWM */
183 	pwm_enable(ssd130x->pwm);
184 
185 	dev_dbg(dev, "Using PWM%d with a %lluns period.\n",
186 		ssd130x->pwm->pwm, pwm_get_period(ssd130x->pwm));
187 
188 	return 0;
189 }
190 
191 static void ssd130x_reset(struct ssd130x_device *ssd130x)
192 {
193 	if (!ssd130x->reset)
194 		return;
195 
196 	/* Reset the screen */
197 	gpiod_set_value_cansleep(ssd130x->reset, 1);
198 	udelay(4);
199 	gpiod_set_value_cansleep(ssd130x->reset, 0);
200 	udelay(4);
201 }
202 
203 static int ssd130x_power_on(struct ssd130x_device *ssd130x)
204 {
205 	struct device *dev = ssd130x->dev;
206 	int ret;
207 
208 	ssd130x_reset(ssd130x);
209 
210 	ret = regulator_enable(ssd130x->vcc_reg);
211 	if (ret) {
212 		dev_err(dev, "Failed to enable VCC: %d\n", ret);
213 		return ret;
214 	}
215 
216 	if (ssd130x->device_info->need_pwm) {
217 		ret = ssd130x_pwm_enable(ssd130x);
218 		if (ret) {
219 			dev_err(dev, "Failed to enable PWM: %d\n", ret);
220 			regulator_disable(ssd130x->vcc_reg);
221 			return ret;
222 		}
223 	}
224 
225 	return 0;
226 }
227 
228 static void ssd130x_power_off(struct ssd130x_device *ssd130x)
229 {
230 	pwm_disable(ssd130x->pwm);
231 	pwm_put(ssd130x->pwm);
232 
233 	regulator_disable(ssd130x->vcc_reg);
234 }
235 
236 static int ssd130x_init(struct ssd130x_device *ssd130x)
237 {
238 	u32 precharge, dclk, com_invdir, compins, chargepump;
239 	int ret;
240 
241 	/* Set initial contrast */
242 	ret = ssd130x_write_cmd(ssd130x, 2, SSD130X_CONTRAST, ssd130x->contrast);
243 	if (ret < 0)
244 		return ret;
245 
246 	/* Set segment re-map */
247 	if (ssd130x->seg_remap) {
248 		ret = ssd130x_write_cmd(ssd130x, 1, SSD130X_SEG_REMAP_ON);
249 		if (ret < 0)
250 			return ret;
251 	}
252 
253 	/* Set COM direction */
254 	com_invdir = (SSD130X_SET_COM_SCAN_DIR |
255 		      SSD130X_SET_COM_SCAN_DIR_SET(ssd130x->com_invdir));
256 	ret = ssd130x_write_cmd(ssd130x,  1, com_invdir);
257 	if (ret < 0)
258 		return ret;
259 
260 	/* Set multiplex ratio value */
261 	ret = ssd130x_write_cmd(ssd130x, 2, SSD130X_SET_MULTIPLEX_RATIO, ssd130x->height - 1);
262 	if (ret < 0)
263 		return ret;
264 
265 	/* set display offset value */
266 	ret = ssd130x_write_cmd(ssd130x, 2, SSD130X_SET_DISPLAY_OFFSET, ssd130x->com_offset);
267 	if (ret < 0)
268 		return ret;
269 
270 	/* Set clock frequency */
271 	dclk = (SSD130X_SET_CLOCK_DIV_SET(ssd130x->dclk_div - 1) |
272 		SSD130X_SET_CLOCK_FREQ_SET(ssd130x->dclk_frq));
273 	ret = ssd130x_write_cmd(ssd130x, 2, SSD130X_SET_CLOCK_FREQ, dclk);
274 	if (ret < 0)
275 		return ret;
276 
277 	/* Set Area Color Mode ON/OFF & Low Power Display Mode */
278 	if (ssd130x->area_color_enable || ssd130x->low_power) {
279 		u32 mode = 0;
280 
281 		if (ssd130x->area_color_enable)
282 			mode |= SSD130X_SET_AREA_COLOR_MODE_ENABLE;
283 
284 		if (ssd130x->low_power)
285 			mode |= SSD130X_SET_AREA_COLOR_MODE_LOW_POWER;
286 
287 		ret = ssd130x_write_cmd(ssd130x, 2, SSD130X_SET_AREA_COLOR_MODE, mode);
288 		if (ret < 0)
289 			return ret;
290 	}
291 
292 	/* Set precharge period in number of ticks from the internal clock */
293 	precharge = (SSD130X_SET_PRECHARGE_PERIOD1_SET(ssd130x->prechargep1) |
294 		     SSD130X_SET_PRECHARGE_PERIOD1_SET(ssd130x->prechargep2));
295 	ret = ssd130x_write_cmd(ssd130x, 2, SSD130X_SET_PRECHARGE_PERIOD, precharge);
296 	if (ret < 0)
297 		return ret;
298 
299 	/* Set COM pins configuration */
300 	compins = BIT(1);
301 	compins |= (SSD130X_SET_COM_PINS_CONFIG1_SET(ssd130x->com_seq) |
302 		    SSD130X_SET_COM_PINS_CONFIG2_SET(ssd130x->com_lrremap));
303 	ret = ssd130x_write_cmd(ssd130x, 2, SSD130X_SET_COM_PINS_CONFIG, compins);
304 	if (ret < 0)
305 		return ret;
306 
307 	/* Set VCOMH */
308 	ret = ssd130x_write_cmd(ssd130x, 2, SSD130X_SET_VCOMH, ssd130x->vcomh);
309 	if (ret < 0)
310 		return ret;
311 
312 	/* Turn on the DC-DC Charge Pump */
313 	chargepump = BIT(4);
314 
315 	if (ssd130x->device_info->need_chargepump)
316 		chargepump |= BIT(2);
317 
318 	ret = ssd130x_write_cmd(ssd130x, 2, SSD130X_CHARGE_PUMP, chargepump);
319 	if (ret < 0)
320 		return ret;
321 
322 	/* Set lookup table */
323 	if (ssd130x->lookup_table_set) {
324 		int i;
325 
326 		ret = ssd130x_write_cmd(ssd130x, 1, SSD130X_SET_LOOKUP_TABLE);
327 		if (ret < 0)
328 			return ret;
329 
330 		for (i = 0; i < ARRAY_SIZE(ssd130x->lookup_table); i++) {
331 			u8 val = ssd130x->lookup_table[i];
332 
333 			if (val < 31 || val > 63)
334 				dev_warn(ssd130x->dev,
335 					 "lookup table index %d value out of range 31 <= %d <= 63\n",
336 					 i, val);
337 			ret = ssd130x_write_cmd(ssd130x, 1, val);
338 			if (ret < 0)
339 				return ret;
340 		}
341 	}
342 
343 	/* Switch to horizontal addressing mode */
344 	return ssd130x_write_cmd(ssd130x, 2, SSD130X_SET_ADDRESS_MODE,
345 				 SSD130X_SET_ADDRESS_MODE_HORIZONTAL);
346 }
347 
348 static int ssd130x_update_rect(struct ssd130x_device *ssd130x, u8 *buf,
349 			       struct drm_rect *rect)
350 {
351 	unsigned int x = rect->x1;
352 	unsigned int y = rect->y1;
353 	unsigned int width = drm_rect_width(rect);
354 	unsigned int height = drm_rect_height(rect);
355 	unsigned int line_length = DIV_ROUND_UP(width, 8);
356 	unsigned int pages = DIV_ROUND_UP(y % 8 + height, 8);
357 	u32 array_idx = 0;
358 	int ret, i, j, k;
359 	u8 *data_array = NULL;
360 
361 	data_array = kcalloc(width, pages, GFP_KERNEL);
362 	if (!data_array)
363 		return -ENOMEM;
364 
365 	/*
366 	 * The screen is divided in pages, each having a height of 8
367 	 * pixels, and the width of the screen. When sending a byte of
368 	 * data to the controller, it gives the 8 bits for the current
369 	 * column. I.e, the first byte are the 8 bits of the first
370 	 * column, then the 8 bits for the second column, etc.
371 	 *
372 	 *
373 	 * Representation of the screen, assuming it is 5 bits
374 	 * wide. Each letter-number combination is a bit that controls
375 	 * one pixel.
376 	 *
377 	 * A0 A1 A2 A3 A4
378 	 * B0 B1 B2 B3 B4
379 	 * C0 C1 C2 C3 C4
380 	 * D0 D1 D2 D3 D4
381 	 * E0 E1 E2 E3 E4
382 	 * F0 F1 F2 F3 F4
383 	 * G0 G1 G2 G3 G4
384 	 * H0 H1 H2 H3 H4
385 	 *
386 	 * If you want to update this screen, you need to send 5 bytes:
387 	 *  (1) A0 B0 C0 D0 E0 F0 G0 H0
388 	 *  (2) A1 B1 C1 D1 E1 F1 G1 H1
389 	 *  (3) A2 B2 C2 D2 E2 F2 G2 H2
390 	 *  (4) A3 B3 C3 D3 E3 F3 G3 H3
391 	 *  (5) A4 B4 C4 D4 E4 F4 G4 H4
392 	 */
393 
394 	ret = ssd130x_set_col_range(ssd130x, ssd130x->col_offset + x, width);
395 	if (ret < 0)
396 		goto out_free;
397 
398 	ret = ssd130x_set_page_range(ssd130x, ssd130x->page_offset + y / 8, pages);
399 	if (ret < 0)
400 		goto out_free;
401 
402 	for (i = y / 8; i < y / 8 + pages; i++) {
403 		int m = 8;
404 
405 		/* Last page may be partial */
406 		if (8 * (i + 1) > ssd130x->height)
407 			m = ssd130x->height % 8;
408 		for (j = x; j < x + width; j++) {
409 			u8 data = 0;
410 
411 			for (k = 0; k < m; k++) {
412 				u8 byte = buf[(8 * i + k) * line_length + j / 8];
413 				u8 bit = (byte >> (j % 8)) & 1;
414 
415 				data |= bit << k;
416 			}
417 			data_array[array_idx++] = data;
418 		}
419 	}
420 
421 	ret = ssd130x_write_data(ssd130x, data_array, width * pages);
422 
423 out_free:
424 	kfree(data_array);
425 	return ret;
426 }
427 
428 static void ssd130x_clear_screen(struct ssd130x_device *ssd130x)
429 {
430 	u8 *buf = NULL;
431 	struct drm_rect fullscreen = {
432 		.x1 = 0,
433 		.x2 = ssd130x->width,
434 		.y1 = 0,
435 		.y2 = ssd130x->height,
436 	};
437 
438 	buf = kcalloc(ssd130x->width, ssd130x->height, GFP_KERNEL);
439 	if (!buf)
440 		return;
441 
442 	ssd130x_update_rect(ssd130x, buf, &fullscreen);
443 
444 	kfree(buf);
445 }
446 
447 static int ssd130x_fb_blit_rect(struct drm_framebuffer *fb, const struct iosys_map *map,
448 				struct drm_rect *rect)
449 {
450 	struct ssd130x_device *ssd130x = drm_to_ssd130x(fb->dev);
451 	void *vmap = map->vaddr; /* TODO: Use mapping abstraction properly */
452 	int ret = 0;
453 	u8 *buf = NULL;
454 
455 	buf = kcalloc(fb->width, fb->height, GFP_KERNEL);
456 	if (!buf)
457 		return -ENOMEM;
458 
459 	drm_fb_xrgb8888_to_mono_reversed(buf, 0, vmap, fb, rect);
460 
461 	ssd130x_update_rect(ssd130x, buf, rect);
462 
463 	kfree(buf);
464 
465 	return ret;
466 }
467 
468 static int ssd130x_display_pipe_mode_valid(struct drm_simple_display_pipe *pipe,
469 					   const struct drm_display_mode *mode)
470 {
471 	struct ssd130x_device *ssd130x = drm_to_ssd130x(pipe->crtc.dev);
472 
473 	if (mode->hdisplay != ssd130x->mode.hdisplay &&
474 	    mode->vdisplay != ssd130x->mode.vdisplay)
475 		return MODE_ONE_SIZE;
476 
477 	if (mode->hdisplay != ssd130x->mode.hdisplay)
478 		return MODE_ONE_WIDTH;
479 
480 	if (mode->vdisplay != ssd130x->mode.vdisplay)
481 		return MODE_ONE_HEIGHT;
482 
483 	return MODE_OK;
484 }
485 
486 static void ssd130x_display_pipe_enable(struct drm_simple_display_pipe *pipe,
487 					struct drm_crtc_state *crtc_state,
488 					struct drm_plane_state *plane_state)
489 {
490 	struct ssd130x_device *ssd130x = drm_to_ssd130x(pipe->crtc.dev);
491 	struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(plane_state);
492 	struct drm_device *drm = &ssd130x->drm;
493 	int idx, ret;
494 
495 	ret = ssd130x_power_on(ssd130x);
496 	if (ret)
497 		return;
498 
499 	ret = ssd130x_init(ssd130x);
500 	if (ret)
501 		goto out_power_off;
502 
503 	if (!drm_dev_enter(drm, &idx))
504 		goto out_power_off;
505 
506 	ssd130x_fb_blit_rect(plane_state->fb, &shadow_plane_state->data[0], &plane_state->dst);
507 
508 	ssd130x_write_cmd(ssd130x, 1, SSD130X_DISPLAY_ON);
509 
510 	backlight_enable(ssd130x->bl_dev);
511 
512 	drm_dev_exit(idx);
513 
514 	return;
515 out_power_off:
516 	ssd130x_power_off(ssd130x);
517 }
518 
519 static void ssd130x_display_pipe_disable(struct drm_simple_display_pipe *pipe)
520 {
521 	struct ssd130x_device *ssd130x = drm_to_ssd130x(pipe->crtc.dev);
522 	struct drm_device *drm = &ssd130x->drm;
523 	int idx;
524 
525 	if (!drm_dev_enter(drm, &idx))
526 		return;
527 
528 	ssd130x_clear_screen(ssd130x);
529 
530 	backlight_disable(ssd130x->bl_dev);
531 
532 	ssd130x_write_cmd(ssd130x, 1, SSD130X_DISPLAY_OFF);
533 
534 	ssd130x_power_off(ssd130x);
535 
536 	drm_dev_exit(idx);
537 }
538 
539 static void ssd130x_display_pipe_update(struct drm_simple_display_pipe *pipe,
540 					struct drm_plane_state *old_plane_state)
541 {
542 	struct ssd130x_device *ssd130x = drm_to_ssd130x(pipe->crtc.dev);
543 	struct drm_plane_state *plane_state = pipe->plane.state;
544 	struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(plane_state);
545 	struct drm_framebuffer *fb = plane_state->fb;
546 	struct drm_device *drm = &ssd130x->drm;
547 	struct drm_rect src_clip, dst_clip;
548 	int idx;
549 
550 	if (!fb)
551 		return;
552 
553 	if (!pipe->crtc.state->active)
554 		return;
555 
556 	if (!drm_atomic_helper_damage_merged(old_plane_state, plane_state, &src_clip))
557 		return;
558 
559 	dst_clip = plane_state->dst;
560 	if (!drm_rect_intersect(&dst_clip, &src_clip))
561 		return;
562 
563 	if (!drm_dev_enter(drm, &idx))
564 		return;
565 
566 	ssd130x_fb_blit_rect(plane_state->fb, &shadow_plane_state->data[0], &dst_clip);
567 
568 	drm_dev_exit(idx);
569 }
570 
571 static const struct drm_simple_display_pipe_funcs ssd130x_pipe_funcs = {
572 	.mode_valid = ssd130x_display_pipe_mode_valid,
573 	.enable = ssd130x_display_pipe_enable,
574 	.disable = ssd130x_display_pipe_disable,
575 	.update = ssd130x_display_pipe_update,
576 	DRM_GEM_SIMPLE_DISPLAY_PIPE_SHADOW_PLANE_FUNCS,
577 };
578 
579 static int ssd130x_connector_get_modes(struct drm_connector *connector)
580 {
581 	struct ssd130x_device *ssd130x = drm_to_ssd130x(connector->dev);
582 	struct drm_display_mode *mode;
583 	struct device *dev = ssd130x->dev;
584 
585 	mode = drm_mode_duplicate(connector->dev, &ssd130x->mode);
586 	if (!mode) {
587 		dev_err(dev, "Failed to duplicated mode\n");
588 		return 0;
589 	}
590 
591 	drm_mode_probed_add(connector, mode);
592 	drm_set_preferred_mode(connector, mode->hdisplay, mode->vdisplay);
593 
594 	/* There is only a single mode */
595 	return 1;
596 }
597 
598 static const struct drm_connector_helper_funcs ssd130x_connector_helper_funcs = {
599 	.get_modes = ssd130x_connector_get_modes,
600 };
601 
602 static const struct drm_connector_funcs ssd130x_connector_funcs = {
603 	.reset = drm_atomic_helper_connector_reset,
604 	.fill_modes = drm_helper_probe_single_connector_modes,
605 	.destroy = drm_connector_cleanup,
606 	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
607 	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
608 };
609 
610 static const struct drm_mode_config_funcs ssd130x_mode_config_funcs = {
611 	.fb_create = drm_gem_fb_create_with_dirty,
612 	.atomic_check = drm_atomic_helper_check,
613 	.atomic_commit = drm_atomic_helper_commit,
614 };
615 
616 static const uint32_t ssd130x_formats[] = {
617 	DRM_FORMAT_XRGB8888,
618 };
619 
620 DEFINE_DRM_GEM_FOPS(ssd130x_fops);
621 
622 static const struct drm_driver ssd130x_drm_driver = {
623 	DRM_GEM_SHMEM_DRIVER_OPS,
624 	.name			= DRIVER_NAME,
625 	.desc			= DRIVER_DESC,
626 	.date			= DRIVER_DATE,
627 	.major			= DRIVER_MAJOR,
628 	.minor			= DRIVER_MINOR,
629 	.driver_features	= DRIVER_ATOMIC | DRIVER_GEM | DRIVER_MODESET,
630 	.fops			= &ssd130x_fops,
631 };
632 
633 static int ssd130x_update_bl(struct backlight_device *bdev)
634 {
635 	struct ssd130x_device *ssd130x = bl_get_data(bdev);
636 	int brightness = backlight_get_brightness(bdev);
637 	int ret;
638 
639 	ssd130x->contrast = brightness;
640 
641 	ret = ssd130x_write_cmd(ssd130x, 1, SSD130X_CONTRAST);
642 	if (ret < 0)
643 		return ret;
644 
645 	ret = ssd130x_write_cmd(ssd130x, 1, ssd130x->contrast);
646 	if (ret < 0)
647 		return ret;
648 
649 	return 0;
650 }
651 
652 static const struct backlight_ops ssd130xfb_bl_ops = {
653 	.update_status	= ssd130x_update_bl,
654 };
655 
656 static void ssd130x_parse_properties(struct ssd130x_device *ssd130x)
657 {
658 	struct device *dev = ssd130x->dev;
659 
660 	if (device_property_read_u32(dev, "solomon,width", &ssd130x->width))
661 		ssd130x->width = 96;
662 
663 	if (device_property_read_u32(dev, "solomon,height", &ssd130x->height))
664 		ssd130x->height = 16;
665 
666 	if (device_property_read_u32(dev, "solomon,page-offset", &ssd130x->page_offset))
667 		ssd130x->page_offset = 1;
668 
669 	if (device_property_read_u32(dev, "solomon,col-offset", &ssd130x->col_offset))
670 		ssd130x->col_offset = 0;
671 
672 	if (device_property_read_u32(dev, "solomon,com-offset", &ssd130x->com_offset))
673 		ssd130x->com_offset = 0;
674 
675 	if (device_property_read_u32(dev, "solomon,prechargep1", &ssd130x->prechargep1))
676 		ssd130x->prechargep1 = 2;
677 
678 	if (device_property_read_u32(dev, "solomon,prechargep2", &ssd130x->prechargep2))
679 		ssd130x->prechargep2 = 2;
680 
681 	if (!device_property_read_u8_array(dev, "solomon,lookup-table",
682 					   ssd130x->lookup_table,
683 					   ARRAY_SIZE(ssd130x->lookup_table)))
684 		ssd130x->lookup_table_set = 1;
685 
686 	ssd130x->seg_remap = !device_property_read_bool(dev, "solomon,segment-no-remap");
687 	ssd130x->com_seq = device_property_read_bool(dev, "solomon,com-seq");
688 	ssd130x->com_lrremap = device_property_read_bool(dev, "solomon,com-lrremap");
689 	ssd130x->com_invdir = device_property_read_bool(dev, "solomon,com-invdir");
690 	ssd130x->area_color_enable =
691 		device_property_read_bool(dev, "solomon,area-color-enable");
692 	ssd130x->low_power = device_property_read_bool(dev, "solomon,low-power");
693 
694 	ssd130x->contrast = 127;
695 	ssd130x->vcomh = ssd130x->device_info->default_vcomh;
696 
697 	/* Setup display timing */
698 	if (device_property_read_u32(dev, "solomon,dclk-div", &ssd130x->dclk_div))
699 		ssd130x->dclk_div = ssd130x->device_info->default_dclk_div;
700 	if (device_property_read_u32(dev, "solomon,dclk-frq", &ssd130x->dclk_frq))
701 		ssd130x->dclk_frq = ssd130x->device_info->default_dclk_frq;
702 }
703 
704 static int ssd130x_init_modeset(struct ssd130x_device *ssd130x)
705 {
706 	struct drm_display_mode *mode = &ssd130x->mode;
707 	struct device *dev = ssd130x->dev;
708 	struct drm_device *drm = &ssd130x->drm;
709 	unsigned long max_width, max_height;
710 	int ret;
711 
712 	ret = drmm_mode_config_init(drm);
713 	if (ret) {
714 		dev_err(dev, "DRM mode config init failed: %d\n", ret);
715 		return ret;
716 	}
717 
718 	mode->type = DRM_MODE_TYPE_DRIVER;
719 	mode->clock = 1;
720 	mode->hdisplay = mode->htotal = ssd130x->width;
721 	mode->hsync_start = mode->hsync_end = ssd130x->width;
722 	mode->vdisplay = mode->vtotal = ssd130x->height;
723 	mode->vsync_start = mode->vsync_end = ssd130x->height;
724 	mode->width_mm = 27;
725 	mode->height_mm = 27;
726 
727 	max_width = max_t(unsigned long, mode->hdisplay, DRM_SHADOW_PLANE_MAX_WIDTH);
728 	max_height = max_t(unsigned long, mode->vdisplay, DRM_SHADOW_PLANE_MAX_HEIGHT);
729 
730 	drm->mode_config.min_width = mode->hdisplay;
731 	drm->mode_config.max_width = max_width;
732 	drm->mode_config.min_height = mode->vdisplay;
733 	drm->mode_config.max_height = max_height;
734 	drm->mode_config.preferred_depth = 32;
735 	drm->mode_config.funcs = &ssd130x_mode_config_funcs;
736 
737 	ret = drm_connector_init(drm, &ssd130x->connector, &ssd130x_connector_funcs,
738 				 DRM_MODE_CONNECTOR_Unknown);
739 	if (ret) {
740 		dev_err(dev, "DRM connector init failed: %d\n", ret);
741 		return ret;
742 	}
743 
744 	drm_connector_helper_add(&ssd130x->connector, &ssd130x_connector_helper_funcs);
745 
746 	ret = drm_simple_display_pipe_init(drm, &ssd130x->pipe, &ssd130x_pipe_funcs,
747 					   ssd130x_formats, ARRAY_SIZE(ssd130x_formats),
748 					   NULL, &ssd130x->connector);
749 	if (ret) {
750 		dev_err(dev, "DRM simple display pipeline init failed: %d\n", ret);
751 		return ret;
752 	}
753 
754 	drm_plane_enable_fb_damage_clips(&ssd130x->pipe.plane);
755 
756 	drm_mode_config_reset(drm);
757 
758 	return 0;
759 }
760 
761 static int ssd130x_get_resources(struct ssd130x_device *ssd130x)
762 {
763 	struct device *dev = ssd130x->dev;
764 
765 	ssd130x->reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
766 	if (IS_ERR(ssd130x->reset))
767 		return dev_err_probe(dev, PTR_ERR(ssd130x->reset),
768 				     "Failed to get reset gpio\n");
769 
770 	ssd130x->vcc_reg = devm_regulator_get(dev, "vcc");
771 	if (IS_ERR(ssd130x->vcc_reg))
772 		return dev_err_probe(dev, PTR_ERR(ssd130x->vcc_reg),
773 				     "Failed to get VCC regulator\n");
774 
775 	return 0;
776 }
777 
778 struct ssd130x_device *ssd130x_probe(struct device *dev, struct regmap *regmap)
779 {
780 	struct ssd130x_device *ssd130x;
781 	struct backlight_device *bl;
782 	struct drm_device *drm;
783 	int ret;
784 
785 	ssd130x = devm_drm_dev_alloc(dev, &ssd130x_drm_driver,
786 				     struct ssd130x_device, drm);
787 	if (IS_ERR(ssd130x))
788 		return ERR_PTR(dev_err_probe(dev, PTR_ERR(ssd130x),
789 					     "Failed to allocate DRM device\n"));
790 
791 	drm = &ssd130x->drm;
792 
793 	ssd130x->dev = dev;
794 	ssd130x->regmap = regmap;
795 	ssd130x->device_info = device_get_match_data(dev);
796 
797 	ssd130x_parse_properties(ssd130x);
798 
799 	ret = ssd130x_get_resources(ssd130x);
800 	if (ret)
801 		return ERR_PTR(ret);
802 
803 	bl = devm_backlight_device_register(dev, dev_name(dev), dev, ssd130x,
804 					    &ssd130xfb_bl_ops, NULL);
805 	if (IS_ERR(bl))
806 		return ERR_PTR(dev_err_probe(dev, PTR_ERR(bl),
807 					     "Unable to register backlight device\n"));
808 
809 	bl->props.brightness = ssd130x->contrast;
810 	bl->props.max_brightness = MAX_CONTRAST;
811 	ssd130x->bl_dev = bl;
812 
813 	ret = ssd130x_init_modeset(ssd130x);
814 	if (ret)
815 		return ERR_PTR(ret);
816 
817 	ret = drm_dev_register(drm, 0);
818 	if (ret)
819 		return ERR_PTR(dev_err_probe(dev, ret, "DRM device register failed\n"));
820 
821 	drm_fbdev_generic_setup(drm, 0);
822 
823 	return ssd130x;
824 }
825 EXPORT_SYMBOL_GPL(ssd130x_probe);
826 
827 int ssd130x_remove(struct ssd130x_device *ssd130x)
828 {
829 	drm_dev_unplug(&ssd130x->drm);
830 
831 	return 0;
832 }
833 EXPORT_SYMBOL_GPL(ssd130x_remove);
834 
835 void ssd130x_shutdown(struct ssd130x_device *ssd130x)
836 {
837 	drm_atomic_helper_shutdown(&ssd130x->drm);
838 }
839 EXPORT_SYMBOL_GPL(ssd130x_shutdown);
840 
841 MODULE_DESCRIPTION(DRIVER_DESC);
842 MODULE_AUTHOR("Javier Martinez Canillas <javierm@redhat.com>");
843 MODULE_LICENSE("GPL v2");
844