xref: /linux/drivers/auxdisplay/ht16k33.c (revision 24168c5e6dfbdd5b414f048f47f75d64533296ca)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * HT16K33 driver
4  *
5  * Author: Robin van der Gracht <robin@protonic.nl>
6  *
7  * Copyright: (C) 2016 Protonic Holland.
8  * Copyright (C) 2021 Glider bv
9  */
10 
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/interrupt.h>
14 #include <linux/i2c.h>
15 #include <linux/property.h>
16 #include <linux/fb.h>
17 #include <linux/backlight.h>
18 #include <linux/container_of.h>
19 #include <linux/input.h>
20 #include <linux/input/matrix_keypad.h>
21 #include <linux/leds.h>
22 #include <linux/workqueue.h>
23 #include <linux/mm.h>
24 
25 #include <linux/map_to_7segment.h>
26 #include <linux/map_to_14segment.h>
27 
28 #include <asm/unaligned.h>
29 
30 #include "line-display.h"
31 
32 /* Registers */
33 #define REG_SYSTEM_SETUP		0x20
34 #define REG_SYSTEM_SETUP_OSC_ON		BIT(0)
35 
36 #define REG_DISPLAY_SETUP		0x80
37 #define REG_DISPLAY_SETUP_ON		BIT(0)
38 #define REG_DISPLAY_SETUP_BLINK_OFF	(0 << 1)
39 #define REG_DISPLAY_SETUP_BLINK_2HZ	(1 << 1)
40 #define REG_DISPLAY_SETUP_BLINK_1HZ	(2 << 1)
41 #define REG_DISPLAY_SETUP_BLINK_0HZ5	(3 << 1)
42 
43 #define REG_ROWINT_SET			0xA0
44 #define REG_ROWINT_SET_INT_EN		BIT(0)
45 #define REG_ROWINT_SET_INT_ACT_HIGH	BIT(1)
46 
47 #define REG_BRIGHTNESS			0xE0
48 
49 /* Defines */
50 #define DRIVER_NAME			"ht16k33"
51 
52 #define MIN_BRIGHTNESS			0x1
53 #define MAX_BRIGHTNESS			0x10
54 
55 #define HT16K33_MATRIX_LED_MAX_COLS	8
56 #define HT16K33_MATRIX_LED_MAX_ROWS	16
57 #define HT16K33_MATRIX_KEYPAD_MAX_COLS	3
58 #define HT16K33_MATRIX_KEYPAD_MAX_ROWS	12
59 
60 #define BYTES_PER_ROW		(HT16K33_MATRIX_LED_MAX_ROWS / 8)
61 #define HT16K33_FB_SIZE		(HT16K33_MATRIX_LED_MAX_COLS * BYTES_PER_ROW)
62 
63 enum display_type {
64 	DISP_MATRIX = 0,
65 	DISP_QUAD_7SEG,
66 	DISP_QUAD_14SEG,
67 };
68 
69 struct ht16k33_keypad {
70 	struct i2c_client *client;
71 	struct input_dev *dev;
72 	uint32_t cols;
73 	uint32_t rows;
74 	uint32_t row_shift;
75 	uint32_t debounce_ms;
76 	uint16_t last_key_state[HT16K33_MATRIX_KEYPAD_MAX_COLS];
77 
78 	wait_queue_head_t wait;
79 	bool stopped;
80 };
81 
82 struct ht16k33_fbdev {
83 	struct fb_info *info;
84 	uint32_t refresh_rate;
85 	uint8_t *buffer;
86 	uint8_t *cache;
87 };
88 
89 struct ht16k33_priv {
90 	struct i2c_client *client;
91 	struct delayed_work work;
92 	struct led_classdev led;
93 	struct ht16k33_keypad keypad;
94 	union {
95 		struct ht16k33_fbdev fbdev;
96 		struct linedisp linedisp;
97 	};
98 	enum display_type type;
99 	uint8_t blink;
100 };
101 
102 #define ht16k33_work_to_priv(p)				\
103 	container_of(p, struct ht16k33_priv, work.work)
104 
105 #define ht16k33_led_to_priv(p)				\
106 	container_of(p, struct ht16k33_priv, led)
107 
108 #define ht16k33_linedisp_to_priv(p)			\
109 	container_of(p, struct ht16k33_priv, linedisp)
110 
111 static const struct fb_fix_screeninfo ht16k33_fb_fix = {
112 	.id		= DRIVER_NAME,
113 	.type		= FB_TYPE_PACKED_PIXELS,
114 	.visual		= FB_VISUAL_MONO10,
115 	.xpanstep	= 0,
116 	.ypanstep	= 0,
117 	.ywrapstep	= 0,
118 	.line_length	= HT16K33_MATRIX_LED_MAX_ROWS,
119 	.accel		= FB_ACCEL_NONE,
120 };
121 
122 static const struct fb_var_screeninfo ht16k33_fb_var = {
123 	.xres = HT16K33_MATRIX_LED_MAX_ROWS,
124 	.yres = HT16K33_MATRIX_LED_MAX_COLS,
125 	.xres_virtual = HT16K33_MATRIX_LED_MAX_ROWS,
126 	.yres_virtual = HT16K33_MATRIX_LED_MAX_COLS,
127 	.bits_per_pixel = 1,
128 	.red = { 0, 1, 0 },
129 	.green = { 0, 1, 0 },
130 	.blue = { 0, 1, 0 },
131 	.left_margin = 0,
132 	.right_margin = 0,
133 	.upper_margin = 0,
134 	.lower_margin = 0,
135 	.vmode = FB_VMODE_NONINTERLACED,
136 };
137 
138 static int ht16k33_display_on(struct ht16k33_priv *priv)
139 {
140 	uint8_t data = REG_DISPLAY_SETUP | REG_DISPLAY_SETUP_ON | priv->blink;
141 
142 	return i2c_smbus_write_byte(priv->client, data);
143 }
144 
145 static int ht16k33_display_off(struct ht16k33_priv *priv)
146 {
147 	return i2c_smbus_write_byte(priv->client, REG_DISPLAY_SETUP);
148 }
149 
150 static int ht16k33_brightness_set(struct ht16k33_priv *priv,
151 				  unsigned int brightness)
152 {
153 	int err;
154 
155 	if (brightness == 0) {
156 		priv->blink = REG_DISPLAY_SETUP_BLINK_OFF;
157 		return ht16k33_display_off(priv);
158 	}
159 
160 	err = ht16k33_display_on(priv);
161 	if (err)
162 		return err;
163 
164 	return i2c_smbus_write_byte(priv->client,
165 				    REG_BRIGHTNESS | (brightness - 1));
166 }
167 
168 static int ht16k33_brightness_set_blocking(struct led_classdev *led_cdev,
169 					   enum led_brightness brightness)
170 {
171 	struct ht16k33_priv *priv = ht16k33_led_to_priv(led_cdev);
172 
173 	return ht16k33_brightness_set(priv, brightness);
174 }
175 
176 static int ht16k33_blink_set(struct led_classdev *led_cdev,
177 			     unsigned long *delay_on, unsigned long *delay_off)
178 {
179 	struct ht16k33_priv *priv = ht16k33_led_to_priv(led_cdev);
180 	unsigned int delay;
181 	uint8_t blink;
182 	int err;
183 
184 	if (!*delay_on && !*delay_off) {
185 		blink = REG_DISPLAY_SETUP_BLINK_1HZ;
186 		delay = 1000;
187 	} else if (*delay_on <= 750) {
188 		blink = REG_DISPLAY_SETUP_BLINK_2HZ;
189 		delay = 500;
190 	} else if (*delay_on <= 1500) {
191 		blink = REG_DISPLAY_SETUP_BLINK_1HZ;
192 		delay = 1000;
193 	} else {
194 		blink = REG_DISPLAY_SETUP_BLINK_0HZ5;
195 		delay = 2000;
196 	}
197 
198 	err = i2c_smbus_write_byte(priv->client,
199 				   REG_DISPLAY_SETUP | REG_DISPLAY_SETUP_ON |
200 				   blink);
201 	if (err)
202 		return err;
203 
204 	priv->blink = blink;
205 	*delay_on = *delay_off = delay;
206 	return 0;
207 }
208 
209 static void ht16k33_fb_queue(struct ht16k33_priv *priv)
210 {
211 	struct ht16k33_fbdev *fbdev = &priv->fbdev;
212 
213 	schedule_delayed_work(&priv->work, HZ / fbdev->refresh_rate);
214 }
215 
216 /*
217  * This gets the fb data from cache and copies it to ht16k33 display RAM
218  */
219 static void ht16k33_fb_update(struct work_struct *work)
220 {
221 	struct ht16k33_priv *priv = ht16k33_work_to_priv(work);
222 	struct ht16k33_fbdev *fbdev = &priv->fbdev;
223 
224 	uint8_t *p1, *p2;
225 	int len, pos = 0, first = -1;
226 
227 	p1 = fbdev->cache;
228 	p2 = fbdev->buffer;
229 
230 	/* Search for the first byte with changes */
231 	while (pos < HT16K33_FB_SIZE && first < 0) {
232 		if (*(p1++) - *(p2++))
233 			first = pos;
234 		pos++;
235 	}
236 
237 	/* No changes found */
238 	if (first < 0)
239 		goto requeue;
240 
241 	len = HT16K33_FB_SIZE - first;
242 	p1 = fbdev->cache + HT16K33_FB_SIZE - 1;
243 	p2 = fbdev->buffer + HT16K33_FB_SIZE - 1;
244 
245 	/* Determine i2c transfer length */
246 	while (len > 1) {
247 		if (*(p1--) - *(p2--))
248 			break;
249 		len--;
250 	}
251 
252 	p1 = fbdev->cache + first;
253 	p2 = fbdev->buffer + first;
254 	if (!i2c_smbus_write_i2c_block_data(priv->client, first, len, p2))
255 		memcpy(p1, p2, len);
256 requeue:
257 	ht16k33_fb_queue(priv);
258 }
259 
260 static int ht16k33_initialize(struct ht16k33_priv *priv)
261 {
262 	uint8_t data[HT16K33_FB_SIZE];
263 	uint8_t byte;
264 	int err;
265 
266 	/* Clear RAM (8 * 16 bits) */
267 	memset(data, 0, sizeof(data));
268 	err = i2c_smbus_write_block_data(priv->client, 0, sizeof(data), data);
269 	if (err)
270 		return err;
271 
272 	/* Turn on internal oscillator */
273 	byte = REG_SYSTEM_SETUP_OSC_ON | REG_SYSTEM_SETUP;
274 	err = i2c_smbus_write_byte(priv->client, byte);
275 	if (err)
276 		return err;
277 
278 	/* Configure INT pin */
279 	byte = REG_ROWINT_SET | REG_ROWINT_SET_INT_ACT_HIGH;
280 	if (priv->client->irq > 0)
281 		byte |= REG_ROWINT_SET_INT_EN;
282 	return i2c_smbus_write_byte(priv->client, byte);
283 }
284 
285 static int ht16k33_bl_update_status(struct backlight_device *bl)
286 {
287 	const int brightness = backlight_get_brightness(bl);
288 	struct ht16k33_priv *priv = bl_get_data(bl);
289 
290 	return ht16k33_brightness_set(priv, brightness);
291 }
292 
293 static const struct backlight_ops ht16k33_bl_ops = {
294 	.update_status	= ht16k33_bl_update_status,
295 };
296 
297 /*
298  * Blank events will be passed to the actual device handling the backlight when
299  * we return zero here.
300  */
301 static int ht16k33_blank(int blank, struct fb_info *info)
302 {
303 	return 0;
304 }
305 
306 static int ht16k33_mmap(struct fb_info *info, struct vm_area_struct *vma)
307 {
308 	struct ht16k33_priv *priv = info->par;
309 	struct page *pages = virt_to_page(priv->fbdev.buffer);
310 
311 	vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot);
312 
313 	return vm_map_pages_zero(vma, &pages, 1);
314 }
315 
316 static const struct fb_ops ht16k33_fb_ops = {
317 	.owner = THIS_MODULE,
318 	__FB_DEFAULT_SYSMEM_OPS_RDWR,
319 	.fb_blank = ht16k33_blank,
320 	__FB_DEFAULT_SYSMEM_OPS_DRAW,
321 	.fb_mmap = ht16k33_mmap,
322 };
323 
324 /*
325  * This gets the keys from keypad and reports it to input subsystem.
326  * Returns true if a key is pressed.
327  */
328 static bool ht16k33_keypad_scan(struct ht16k33_keypad *keypad)
329 {
330 	const unsigned short *keycodes = keypad->dev->keycode;
331 	u16 new_state[HT16K33_MATRIX_KEYPAD_MAX_COLS];
332 	__le16 data[HT16K33_MATRIX_KEYPAD_MAX_COLS];
333 	unsigned long bits_changed;
334 	int row, col, code;
335 	int rc;
336 	bool pressed = false;
337 
338 	rc = i2c_smbus_read_i2c_block_data(keypad->client, 0x40,
339 					   sizeof(data), (u8 *)data);
340 	if (rc != sizeof(data)) {
341 		dev_err(&keypad->client->dev,
342 			"Failed to read key data, rc=%d\n", rc);
343 		return false;
344 	}
345 
346 	for (col = 0; col < keypad->cols; col++) {
347 		new_state[col] = le16_to_cpu(data[col]);
348 		if (new_state[col])
349 			pressed = true;
350 		bits_changed = keypad->last_key_state[col] ^ new_state[col];
351 
352 		for_each_set_bit(row, &bits_changed, BITS_PER_LONG) {
353 			code = MATRIX_SCAN_CODE(row, col, keypad->row_shift);
354 			input_event(keypad->dev, EV_MSC, MSC_SCAN, code);
355 			input_report_key(keypad->dev, keycodes[code],
356 					 new_state[col] & BIT(row));
357 		}
358 	}
359 	input_sync(keypad->dev);
360 	memcpy(keypad->last_key_state, new_state, sizeof(u16) * keypad->cols);
361 
362 	return pressed;
363 }
364 
365 static irqreturn_t ht16k33_keypad_irq_thread(int irq, void *dev)
366 {
367 	struct ht16k33_keypad *keypad = dev;
368 
369 	do {
370 		wait_event_timeout(keypad->wait, keypad->stopped,
371 				    msecs_to_jiffies(keypad->debounce_ms));
372 		if (keypad->stopped)
373 			break;
374 	} while (ht16k33_keypad_scan(keypad));
375 
376 	return IRQ_HANDLED;
377 }
378 
379 static int ht16k33_keypad_start(struct input_dev *dev)
380 {
381 	struct ht16k33_keypad *keypad = input_get_drvdata(dev);
382 
383 	keypad->stopped = false;
384 	mb();
385 	enable_irq(keypad->client->irq);
386 
387 	return 0;
388 }
389 
390 static void ht16k33_keypad_stop(struct input_dev *dev)
391 {
392 	struct ht16k33_keypad *keypad = input_get_drvdata(dev);
393 
394 	keypad->stopped = true;
395 	mb();
396 	wake_up(&keypad->wait);
397 	disable_irq(keypad->client->irq);
398 }
399 
400 static void ht16k33_seg7_update(struct work_struct *work)
401 {
402 	struct ht16k33_priv *priv = ht16k33_work_to_priv(work);
403 	struct linedisp_map *map = priv->linedisp.map;
404 	char *s = priv->linedisp.buf;
405 	uint8_t buf[9];
406 
407 	buf[0] = map_to_seg7(&map->map.seg7, *s++);
408 	buf[1] = 0;
409 	buf[2] = map_to_seg7(&map->map.seg7, *s++);
410 	buf[3] = 0;
411 	buf[4] = 0;
412 	buf[5] = 0;
413 	buf[6] = map_to_seg7(&map->map.seg7, *s++);
414 	buf[7] = 0;
415 	buf[8] = map_to_seg7(&map->map.seg7, *s++);
416 
417 	i2c_smbus_write_i2c_block_data(priv->client, 0, ARRAY_SIZE(buf), buf);
418 }
419 
420 static void ht16k33_seg14_update(struct work_struct *work)
421 {
422 	struct ht16k33_priv *priv = ht16k33_work_to_priv(work);
423 	struct linedisp_map *map = priv->linedisp.map;
424 	char *s = priv->linedisp.buf;
425 	uint8_t buf[8];
426 
427 	put_unaligned_le16(map_to_seg14(&map->map.seg14, *s++), buf + 0);
428 	put_unaligned_le16(map_to_seg14(&map->map.seg14, *s++), buf + 2);
429 	put_unaligned_le16(map_to_seg14(&map->map.seg14, *s++), buf + 4);
430 	put_unaligned_le16(map_to_seg14(&map->map.seg14, *s++), buf + 6);
431 
432 	i2c_smbus_write_i2c_block_data(priv->client, 0, ARRAY_SIZE(buf), buf);
433 }
434 
435 static int ht16k33_linedisp_get_map_type(struct linedisp *linedisp)
436 {
437 	struct ht16k33_priv *priv = ht16k33_linedisp_to_priv(linedisp);
438 
439 	switch (priv->type) {
440 	case DISP_QUAD_7SEG:
441 		INIT_DELAYED_WORK(&priv->work, ht16k33_seg7_update);
442 		return LINEDISP_MAP_SEG7;
443 
444 	case DISP_QUAD_14SEG:
445 		INIT_DELAYED_WORK(&priv->work, ht16k33_seg14_update);
446 		return LINEDISP_MAP_SEG14;
447 
448 	default:
449 		return -EINVAL;
450 	}
451 }
452 
453 static void ht16k33_linedisp_update(struct linedisp *linedisp)
454 {
455 	struct ht16k33_priv *priv = ht16k33_linedisp_to_priv(linedisp);
456 
457 	schedule_delayed_work(&priv->work, 0);
458 }
459 
460 static const struct linedisp_ops ht16k33_linedisp_ops = {
461 	.get_map_type = ht16k33_linedisp_get_map_type,
462 	.update = ht16k33_linedisp_update,
463 };
464 
465 static int ht16k33_led_probe(struct device *dev, struct led_classdev *led,
466 			     unsigned int brightness)
467 {
468 	struct led_init_data init_data = {};
469 	int err;
470 
471 	/* The LED is optional */
472 	init_data.fwnode = device_get_named_child_node(dev, "led");
473 	if (!init_data.fwnode)
474 		return 0;
475 
476 	init_data.devicename = "auxdisplay";
477 	init_data.devname_mandatory = true;
478 
479 	led->brightness_set_blocking = ht16k33_brightness_set_blocking;
480 	led->blink_set = ht16k33_blink_set;
481 	led->flags = LED_CORE_SUSPENDRESUME;
482 	led->brightness = brightness;
483 	led->max_brightness = MAX_BRIGHTNESS;
484 
485 	err = devm_led_classdev_register_ext(dev, led, &init_data);
486 	if (err)
487 		dev_err(dev, "Failed to register LED\n");
488 
489 	return err;
490 }
491 
492 static int ht16k33_keypad_probe(struct i2c_client *client,
493 				struct ht16k33_keypad *keypad)
494 {
495 	struct device *dev = &client->dev;
496 	u32 rows = HT16K33_MATRIX_KEYPAD_MAX_ROWS;
497 	u32 cols = HT16K33_MATRIX_KEYPAD_MAX_COLS;
498 	int err;
499 
500 	keypad->client = client;
501 	init_waitqueue_head(&keypad->wait);
502 
503 	keypad->dev = devm_input_allocate_device(dev);
504 	if (!keypad->dev)
505 		return -ENOMEM;
506 
507 	input_set_drvdata(keypad->dev, keypad);
508 
509 	keypad->dev->name = DRIVER_NAME"-keypad";
510 	keypad->dev->id.bustype = BUS_I2C;
511 	keypad->dev->open = ht16k33_keypad_start;
512 	keypad->dev->close = ht16k33_keypad_stop;
513 
514 	if (!device_property_read_bool(dev, "linux,no-autorepeat"))
515 		__set_bit(EV_REP, keypad->dev->evbit);
516 
517 	err = device_property_read_u32(dev, "debounce-delay-ms",
518 				       &keypad->debounce_ms);
519 	if (err) {
520 		dev_err(dev, "key debounce delay not specified\n");
521 		return err;
522 	}
523 
524 	err = matrix_keypad_parse_properties(dev, &rows, &cols);
525 	if (err)
526 		return err;
527 	if (rows > HT16K33_MATRIX_KEYPAD_MAX_ROWS ||
528 	    cols > HT16K33_MATRIX_KEYPAD_MAX_COLS) {
529 		dev_err(dev, "%u rows or %u cols out of range in DT\n", rows,
530 			cols);
531 		return -ERANGE;
532 	}
533 
534 	keypad->rows = rows;
535 	keypad->cols = cols;
536 	keypad->row_shift = get_count_order(cols);
537 
538 	err = matrix_keypad_build_keymap(NULL, NULL, rows, cols, NULL,
539 					 keypad->dev);
540 	if (err) {
541 		dev_err(dev, "failed to build keymap\n");
542 		return err;
543 	}
544 
545 	err = devm_request_threaded_irq(dev, client->irq, NULL,
546 					ht16k33_keypad_irq_thread,
547 					IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
548 					DRIVER_NAME, keypad);
549 	if (err) {
550 		dev_err(dev, "irq request failed %d, error %d\n", client->irq,
551 			err);
552 		return err;
553 	}
554 
555 	ht16k33_keypad_stop(keypad->dev);
556 
557 	return input_register_device(keypad->dev);
558 }
559 
560 static int ht16k33_fbdev_probe(struct device *dev, struct ht16k33_priv *priv,
561 			       uint32_t brightness)
562 {
563 	struct ht16k33_fbdev *fbdev = &priv->fbdev;
564 	struct backlight_device *bl = NULL;
565 	int err;
566 
567 	if (priv->led.dev) {
568 		err = ht16k33_brightness_set(priv, brightness);
569 		if (err)
570 			return err;
571 	} else {
572 		/* backwards compatibility with DT lacking an led subnode */
573 		struct backlight_properties bl_props;
574 
575 		memset(&bl_props, 0, sizeof(struct backlight_properties));
576 		bl_props.type = BACKLIGHT_RAW;
577 		bl_props.max_brightness = MAX_BRIGHTNESS;
578 
579 		bl = devm_backlight_device_register(dev, DRIVER_NAME"-bl", dev,
580 						    priv, &ht16k33_bl_ops,
581 						    &bl_props);
582 		if (IS_ERR(bl)) {
583 			dev_err(dev, "failed to register backlight\n");
584 			return PTR_ERR(bl);
585 		}
586 
587 		bl->props.brightness = brightness;
588 		ht16k33_bl_update_status(bl);
589 	}
590 
591 	/* Framebuffer (2 bytes per column) */
592 	BUILD_BUG_ON(PAGE_SIZE < HT16K33_FB_SIZE);
593 	fbdev->buffer = (unsigned char *) get_zeroed_page(GFP_KERNEL);
594 	if (!fbdev->buffer)
595 		return -ENOMEM;
596 
597 	fbdev->cache = devm_kmalloc(dev, HT16K33_FB_SIZE, GFP_KERNEL);
598 	if (!fbdev->cache) {
599 		err = -ENOMEM;
600 		goto err_fbdev_buffer;
601 	}
602 
603 	fbdev->info = framebuffer_alloc(0, dev);
604 	if (!fbdev->info) {
605 		err = -ENOMEM;
606 		goto err_fbdev_buffer;
607 	}
608 
609 	err = device_property_read_u32(dev, "refresh-rate-hz",
610 				       &fbdev->refresh_rate);
611 	if (err) {
612 		dev_err(dev, "refresh rate not specified\n");
613 		goto err_fbdev_info;
614 	}
615 	fb_bl_default_curve(fbdev->info, 0, MIN_BRIGHTNESS, MAX_BRIGHTNESS);
616 
617 	INIT_DELAYED_WORK(&priv->work, ht16k33_fb_update);
618 	fbdev->info->fbops = &ht16k33_fb_ops;
619 	fbdev->info->flags |= FBINFO_VIRTFB;
620 	fbdev->info->screen_buffer = fbdev->buffer;
621 	fbdev->info->screen_size = HT16K33_FB_SIZE;
622 	fbdev->info->fix = ht16k33_fb_fix;
623 	fbdev->info->var = ht16k33_fb_var;
624 	fbdev->info->bl_dev = bl;
625 	fbdev->info->pseudo_palette = NULL;
626 	fbdev->info->par = priv;
627 
628 	err = register_framebuffer(fbdev->info);
629 	if (err)
630 		goto err_fbdev_info;
631 
632 	ht16k33_fb_queue(priv);
633 	return 0;
634 
635 err_fbdev_info:
636 	framebuffer_release(fbdev->info);
637 err_fbdev_buffer:
638 	free_page((unsigned long) fbdev->buffer);
639 
640 	return err;
641 }
642 
643 static int ht16k33_seg_probe(struct device *dev, struct ht16k33_priv *priv,
644 			     uint32_t brightness)
645 {
646 	struct linedisp *linedisp = &priv->linedisp;
647 	int err;
648 
649 	err = ht16k33_brightness_set(priv, brightness);
650 	if (err)
651 		return err;
652 
653 	return linedisp_register(linedisp, dev, 4, &ht16k33_linedisp_ops);
654 }
655 
656 static int ht16k33_probe(struct i2c_client *client)
657 {
658 	struct device *dev = &client->dev;
659 	const struct of_device_id *id;
660 	struct ht16k33_priv *priv;
661 	uint32_t dft_brightness;
662 	int err;
663 
664 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
665 		dev_err(dev, "i2c_check_functionality error\n");
666 		return -EIO;
667 	}
668 
669 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
670 	if (!priv)
671 		return -ENOMEM;
672 
673 	priv->client = client;
674 	id = i2c_of_match_device(dev->driver->of_match_table, client);
675 	if (id)
676 		priv->type = (uintptr_t)id->data;
677 	i2c_set_clientdata(client, priv);
678 
679 	err = ht16k33_initialize(priv);
680 	if (err)
681 		return err;
682 
683 	err = device_property_read_u32(dev, "default-brightness-level",
684 				       &dft_brightness);
685 	if (err) {
686 		dft_brightness = MAX_BRIGHTNESS;
687 	} else if (dft_brightness > MAX_BRIGHTNESS) {
688 		dev_warn(dev,
689 			 "invalid default brightness level: %u, using %u\n",
690 			 dft_brightness, MAX_BRIGHTNESS);
691 		dft_brightness = MAX_BRIGHTNESS;
692 	}
693 
694 	/* LED */
695 	err = ht16k33_led_probe(dev, &priv->led, dft_brightness);
696 	if (err)
697 		return err;
698 
699 	/* Keypad */
700 	if (client->irq > 0) {
701 		err = ht16k33_keypad_probe(client, &priv->keypad);
702 		if (err)
703 			return err;
704 	}
705 
706 	switch (priv->type) {
707 	case DISP_MATRIX:
708 		/* Frame Buffer Display */
709 		err = ht16k33_fbdev_probe(dev, priv, dft_brightness);
710 		break;
711 
712 	case DISP_QUAD_7SEG:
713 	case DISP_QUAD_14SEG:
714 		/* Segment Display */
715 		err = ht16k33_seg_probe(dev, priv, dft_brightness);
716 		break;
717 
718 	default:
719 		return -EINVAL;
720 	}
721 	return err;
722 }
723 
724 static void ht16k33_remove(struct i2c_client *client)
725 {
726 	struct ht16k33_priv *priv = i2c_get_clientdata(client);
727 	struct ht16k33_fbdev *fbdev = &priv->fbdev;
728 
729 	cancel_delayed_work_sync(&priv->work);
730 
731 	switch (priv->type) {
732 	case DISP_MATRIX:
733 		unregister_framebuffer(fbdev->info);
734 		framebuffer_release(fbdev->info);
735 		free_page((unsigned long)fbdev->buffer);
736 		break;
737 
738 	case DISP_QUAD_7SEG:
739 	case DISP_QUAD_14SEG:
740 		linedisp_unregister(&priv->linedisp);
741 		break;
742 
743 	default:
744 		break;
745 	}
746 }
747 
748 static const struct i2c_device_id ht16k33_i2c_match[] = {
749 	{ "ht16k33", 0 },
750 	{ }
751 };
752 MODULE_DEVICE_TABLE(i2c, ht16k33_i2c_match);
753 
754 static const struct of_device_id ht16k33_of_match[] = {
755 	{
756 		/* 0.56" 4-Digit 7-Segment FeatherWing Display (Red) */
757 		.compatible = "adafruit,3108", .data = (void *)DISP_QUAD_7SEG,
758 	}, {
759 		/* 0.54" Quad Alphanumeric FeatherWing Display (Red) */
760 		.compatible = "adafruit,3130", .data = (void *)DISP_QUAD_14SEG,
761 	}, {
762 		/* Generic, assumed Dot-Matrix Display */
763 		.compatible = "holtek,ht16k33", .data = (void *)DISP_MATRIX,
764 	},
765 	{ }
766 };
767 MODULE_DEVICE_TABLE(of, ht16k33_of_match);
768 
769 static struct i2c_driver ht16k33_driver = {
770 	.probe		= ht16k33_probe,
771 	.remove		= ht16k33_remove,
772 	.driver		= {
773 		.name		= DRIVER_NAME,
774 		.of_match_table	= ht16k33_of_match,
775 	},
776 	.id_table = ht16k33_i2c_match,
777 };
778 module_i2c_driver(ht16k33_driver);
779 
780 MODULE_DESCRIPTION("Holtek HT16K33 driver");
781 MODULE_LICENSE("GPL");
782 MODULE_IMPORT_NS(LINEDISP);
783 MODULE_AUTHOR("Robin van der Gracht <robin@protonic.nl>");
784