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/input.h>
 19#include <linux/input/matrix_keypad.h>
 20#include <linux/leds.h>
 21#include <linux/workqueue.h>
 22#include <linux/mm.h>
 23
 24#include <linux/map_to_7segment.h>
 25#include <linux/map_to_14segment.h>
 26
 27#include <asm/unaligned.h>
 28
 29#include "line-display.h"
 30
 31/* Registers */
 32#define REG_SYSTEM_SETUP		0x20
 33#define REG_SYSTEM_SETUP_OSC_ON		BIT(0)
 34
 35#define REG_DISPLAY_SETUP		0x80
 36#define REG_DISPLAY_SETUP_ON		BIT(0)
 37#define REG_DISPLAY_SETUP_BLINK_OFF	(0 << 1)
 38#define REG_DISPLAY_SETUP_BLINK_2HZ	(1 << 1)
 39#define REG_DISPLAY_SETUP_BLINK_1HZ	(2 << 1)
 40#define REG_DISPLAY_SETUP_BLINK_0HZ5	(3 << 1)
 41
 42#define REG_ROWINT_SET			0xA0
 43#define REG_ROWINT_SET_INT_EN		BIT(0)
 44#define REG_ROWINT_SET_INT_ACT_HIGH	BIT(1)
 45
 46#define REG_BRIGHTNESS			0xE0
 47
 48/* Defines */
 49#define DRIVER_NAME			"ht16k33"
 50
 51#define MIN_BRIGHTNESS			0x1
 52#define MAX_BRIGHTNESS			0x10
 53
 54#define HT16K33_MATRIX_LED_MAX_COLS	8
 55#define HT16K33_MATRIX_LED_MAX_ROWS	16
 56#define HT16K33_MATRIX_KEYPAD_MAX_COLS	3
 57#define HT16K33_MATRIX_KEYPAD_MAX_ROWS	12
 58
 59#define BYTES_PER_ROW		(HT16K33_MATRIX_LED_MAX_ROWS / 8)
 60#define HT16K33_FB_SIZE		(HT16K33_MATRIX_LED_MAX_COLS * BYTES_PER_ROW)
 61
 62enum display_type {
 63	DISP_MATRIX = 0,
 64	DISP_QUAD_7SEG,
 65	DISP_QUAD_14SEG,
 66};
 67
 68struct ht16k33_keypad {
 69	struct i2c_client *client;
 70	struct input_dev *dev;
 71	uint32_t cols;
 72	uint32_t rows;
 73	uint32_t row_shift;
 74	uint32_t debounce_ms;
 75	uint16_t last_key_state[HT16K33_MATRIX_KEYPAD_MAX_COLS];
 76
 77	wait_queue_head_t wait;
 78	bool stopped;
 79};
 80
 81struct ht16k33_fbdev {
 82	struct fb_info *info;
 83	uint32_t refresh_rate;
 84	uint8_t *buffer;
 85	uint8_t *cache;
 86};
 87
 88struct ht16k33_seg {
 89	struct linedisp linedisp;
 90	union {
 91		struct seg7_conversion_map seg7;
 92		struct seg14_conversion_map seg14;
 93	} map;
 94	unsigned int map_size;
 95	char curr[4];
 96};
 97
 98struct ht16k33_priv {
 99	struct i2c_client *client;
100	struct delayed_work work;
101	struct led_classdev led;
102	struct ht16k33_keypad keypad;
103	union {
104		struct ht16k33_fbdev fbdev;
105		struct ht16k33_seg seg;
106	};
107	enum display_type type;
108	uint8_t blink;
109};
110
111static 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
122static 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
138static const SEG7_DEFAULT_MAP(initial_map_seg7);
139static const SEG14_DEFAULT_MAP(initial_map_seg14);
140
141static ssize_t map_seg_show(struct device *dev, struct device_attribute *attr,
142			    char *buf)
143{
144	struct ht16k33_priv *priv = dev_get_drvdata(dev);
145
146	memcpy(buf, &priv->seg.map, priv->seg.map_size);
147	return priv->seg.map_size;
148}
149
150static ssize_t map_seg_store(struct device *dev, struct device_attribute *attr,
151			     const char *buf, size_t cnt)
152{
153	struct ht16k33_priv *priv = dev_get_drvdata(dev);
154
155	if (cnt != priv->seg.map_size)
156		return -EINVAL;
157
158	memcpy(&priv->seg.map, buf, cnt);
159	return cnt;
160}
161
162static DEVICE_ATTR(map_seg7, 0644, map_seg_show, map_seg_store);
163static DEVICE_ATTR(map_seg14, 0644, map_seg_show, map_seg_store);
164
165static int ht16k33_display_on(struct ht16k33_priv *priv)
166{
167	uint8_t data = REG_DISPLAY_SETUP | REG_DISPLAY_SETUP_ON | priv->blink;
168
169	return i2c_smbus_write_byte(priv->client, data);
170}
171
172static int ht16k33_display_off(struct ht16k33_priv *priv)
173{
174	return i2c_smbus_write_byte(priv->client, REG_DISPLAY_SETUP);
175}
176
177static int ht16k33_brightness_set(struct ht16k33_priv *priv,
178				  unsigned int brightness)
179{
180	int err;
181
182	if (brightness == 0) {
183		priv->blink = REG_DISPLAY_SETUP_BLINK_OFF;
184		return ht16k33_display_off(priv);
185	}
186
187	err = ht16k33_display_on(priv);
188	if (err)
189		return err;
190
191	return i2c_smbus_write_byte(priv->client,
192				    REG_BRIGHTNESS | (brightness - 1));
193}
194
195static int ht16k33_brightness_set_blocking(struct led_classdev *led_cdev,
196					   enum led_brightness brightness)
197{
198	struct ht16k33_priv *priv = container_of(led_cdev, struct ht16k33_priv,
199						 led);
200
201	return ht16k33_brightness_set(priv, brightness);
202}
203
204static int ht16k33_blink_set(struct led_classdev *led_cdev,
205			     unsigned long *delay_on, unsigned long *delay_off)
206{
207	struct ht16k33_priv *priv = container_of(led_cdev, struct ht16k33_priv,
208						 led);
209	unsigned int delay;
210	uint8_t blink;
211	int err;
212
213	if (!*delay_on && !*delay_off) {
214		blink = REG_DISPLAY_SETUP_BLINK_1HZ;
215		delay = 1000;
216	} else if (*delay_on <= 750) {
217		blink = REG_DISPLAY_SETUP_BLINK_2HZ;
218		delay = 500;
219	} else if (*delay_on <= 1500) {
220		blink = REG_DISPLAY_SETUP_BLINK_1HZ;
221		delay = 1000;
222	} else {
223		blink = REG_DISPLAY_SETUP_BLINK_0HZ5;
224		delay = 2000;
225	}
226
227	err = i2c_smbus_write_byte(priv->client,
228				   REG_DISPLAY_SETUP | REG_DISPLAY_SETUP_ON |
229				   blink);
230	if (err)
231		return err;
232
233	priv->blink = blink;
234	*delay_on = *delay_off = delay;
235	return 0;
236}
237
238static void ht16k33_fb_queue(struct ht16k33_priv *priv)
239{
240	struct ht16k33_fbdev *fbdev = &priv->fbdev;
241
242	schedule_delayed_work(&priv->work, HZ / fbdev->refresh_rate);
243}
244
245/*
246 * This gets the fb data from cache and copies it to ht16k33 display RAM
247 */
248static void ht16k33_fb_update(struct work_struct *work)
249{
250	struct ht16k33_priv *priv = container_of(work, struct ht16k33_priv,
251						 work.work);
252	struct ht16k33_fbdev *fbdev = &priv->fbdev;
253
254	uint8_t *p1, *p2;
255	int len, pos = 0, first = -1;
256
257	p1 = fbdev->cache;
258	p2 = fbdev->buffer;
259
260	/* Search for the first byte with changes */
261	while (pos < HT16K33_FB_SIZE && first < 0) {
262		if (*(p1++) - *(p2++))
263			first = pos;
264		pos++;
265	}
266
267	/* No changes found */
268	if (first < 0)
269		goto requeue;
270
271	len = HT16K33_FB_SIZE - first;
272	p1 = fbdev->cache + HT16K33_FB_SIZE - 1;
273	p2 = fbdev->buffer + HT16K33_FB_SIZE - 1;
274
275	/* Determine i2c transfer length */
276	while (len > 1) {
277		if (*(p1--) - *(p2--))
278			break;
279		len--;
280	}
281
282	p1 = fbdev->cache + first;
283	p2 = fbdev->buffer + first;
284	if (!i2c_smbus_write_i2c_block_data(priv->client, first, len, p2))
285		memcpy(p1, p2, len);
286requeue:
287	ht16k33_fb_queue(priv);
288}
289
290static int ht16k33_initialize(struct ht16k33_priv *priv)
291{
292	uint8_t data[HT16K33_FB_SIZE];
293	uint8_t byte;
294	int err;
295
296	/* Clear RAM (8 * 16 bits) */
297	memset(data, 0, sizeof(data));
298	err = i2c_smbus_write_block_data(priv->client, 0, sizeof(data), data);
299	if (err)
300		return err;
301
302	/* Turn on internal oscillator */
303	byte = REG_SYSTEM_SETUP_OSC_ON | REG_SYSTEM_SETUP;
304	err = i2c_smbus_write_byte(priv->client, byte);
305	if (err)
306		return err;
307
308	/* Configure INT pin */
309	byte = REG_ROWINT_SET | REG_ROWINT_SET_INT_ACT_HIGH;
310	if (priv->client->irq > 0)
311		byte |= REG_ROWINT_SET_INT_EN;
312	return i2c_smbus_write_byte(priv->client, byte);
313}
314
315static int ht16k33_bl_update_status(struct backlight_device *bl)
316{
317	int brightness = bl->props.brightness;
318	struct ht16k33_priv *priv = bl_get_data(bl);
319
320	if (bl->props.power != FB_BLANK_UNBLANK ||
321	    bl->props.fb_blank != FB_BLANK_UNBLANK ||
322	    bl->props.state & BL_CORE_FBBLANK)
323		brightness = 0;
324
325	return ht16k33_brightness_set(priv, brightness);
326}
327
328static int ht16k33_bl_check_fb(struct backlight_device *bl, struct fb_info *fi)
329{
330	struct ht16k33_priv *priv = bl_get_data(bl);
331
332	return (fi == NULL) || (fi->par == priv);
333}
334
335static const struct backlight_ops ht16k33_bl_ops = {
336	.update_status	= ht16k33_bl_update_status,
337	.check_fb	= ht16k33_bl_check_fb,
338};
339
340/*
341 * Blank events will be passed to the actual device handling the backlight when
342 * we return zero here.
343 */
344static int ht16k33_blank(int blank, struct fb_info *info)
345{
346	return 0;
347}
348
349static int ht16k33_mmap(struct fb_info *info, struct vm_area_struct *vma)
350{
351	struct ht16k33_priv *priv = info->par;
352	struct page *pages = virt_to_page(priv->fbdev.buffer);
353
354	vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot);
355
356	return vm_map_pages_zero(vma, &pages, 1);
357}
358
359static const struct fb_ops ht16k33_fb_ops = {
360	.owner = THIS_MODULE,
361	__FB_DEFAULT_SYSMEM_OPS_RDWR,
 
362	.fb_blank = ht16k33_blank,
363	__FB_DEFAULT_SYSMEM_OPS_DRAW,
 
 
364	.fb_mmap = ht16k33_mmap,
365};
366
367/*
368 * This gets the keys from keypad and reports it to input subsystem.
369 * Returns true if a key is pressed.
370 */
371static bool ht16k33_keypad_scan(struct ht16k33_keypad *keypad)
372{
373	const unsigned short *keycodes = keypad->dev->keycode;
374	u16 new_state[HT16K33_MATRIX_KEYPAD_MAX_COLS];
375	__le16 data[HT16K33_MATRIX_KEYPAD_MAX_COLS];
376	unsigned long bits_changed;
377	int row, col, code;
378	int rc;
379	bool pressed = false;
380
381	rc = i2c_smbus_read_i2c_block_data(keypad->client, 0x40,
382					   sizeof(data), (u8 *)data);
383	if (rc != sizeof(data)) {
384		dev_err(&keypad->client->dev,
385			"Failed to read key data, rc=%d\n", rc);
386		return false;
387	}
388
389	for (col = 0; col < keypad->cols; col++) {
390		new_state[col] = le16_to_cpu(data[col]);
391		if (new_state[col])
392			pressed = true;
393		bits_changed = keypad->last_key_state[col] ^ new_state[col];
394
395		for_each_set_bit(row, &bits_changed, BITS_PER_LONG) {
396			code = MATRIX_SCAN_CODE(row, col, keypad->row_shift);
397			input_event(keypad->dev, EV_MSC, MSC_SCAN, code);
398			input_report_key(keypad->dev, keycodes[code],
399					 new_state[col] & BIT(row));
400		}
401	}
402	input_sync(keypad->dev);
403	memcpy(keypad->last_key_state, new_state, sizeof(u16) * keypad->cols);
404
405	return pressed;
406}
407
408static irqreturn_t ht16k33_keypad_irq_thread(int irq, void *dev)
409{
410	struct ht16k33_keypad *keypad = dev;
411
412	do {
413		wait_event_timeout(keypad->wait, keypad->stopped,
414				    msecs_to_jiffies(keypad->debounce_ms));
415		if (keypad->stopped)
416			break;
417	} while (ht16k33_keypad_scan(keypad));
418
419	return IRQ_HANDLED;
420}
421
422static int ht16k33_keypad_start(struct input_dev *dev)
423{
424	struct ht16k33_keypad *keypad = input_get_drvdata(dev);
425
426	keypad->stopped = false;
427	mb();
428	enable_irq(keypad->client->irq);
429
430	return 0;
431}
432
433static void ht16k33_keypad_stop(struct input_dev *dev)
434{
435	struct ht16k33_keypad *keypad = input_get_drvdata(dev);
436
437	keypad->stopped = true;
438	mb();
439	wake_up(&keypad->wait);
440	disable_irq(keypad->client->irq);
441}
442
443static void ht16k33_linedisp_update(struct linedisp *linedisp)
444{
445	struct ht16k33_priv *priv = container_of(linedisp, struct ht16k33_priv,
446						 seg.linedisp);
447
448	schedule_delayed_work(&priv->work, 0);
449}
450
451static void ht16k33_seg7_update(struct work_struct *work)
452{
453	struct ht16k33_priv *priv = container_of(work, struct ht16k33_priv,
454						 work.work);
455	struct ht16k33_seg *seg = &priv->seg;
456	char *s = seg->curr;
457	uint8_t buf[9];
458
459	buf[0] = map_to_seg7(&seg->map.seg7, *s++);
460	buf[1] = 0;
461	buf[2] = map_to_seg7(&seg->map.seg7, *s++);
462	buf[3] = 0;
463	buf[4] = 0;
464	buf[5] = 0;
465	buf[6] = map_to_seg7(&seg->map.seg7, *s++);
466	buf[7] = 0;
467	buf[8] = map_to_seg7(&seg->map.seg7, *s++);
468
469	i2c_smbus_write_i2c_block_data(priv->client, 0, ARRAY_SIZE(buf), buf);
470}
471
472static void ht16k33_seg14_update(struct work_struct *work)
473{
474	struct ht16k33_priv *priv = container_of(work, struct ht16k33_priv,
475						 work.work);
476	struct ht16k33_seg *seg = &priv->seg;
477	char *s = seg->curr;
478	uint8_t buf[8];
479
480	put_unaligned_le16(map_to_seg14(&seg->map.seg14, *s++), buf);
481	put_unaligned_le16(map_to_seg14(&seg->map.seg14, *s++), buf + 2);
482	put_unaligned_le16(map_to_seg14(&seg->map.seg14, *s++), buf + 4);
483	put_unaligned_le16(map_to_seg14(&seg->map.seg14, *s++), buf + 6);
484
485	i2c_smbus_write_i2c_block_data(priv->client, 0, ARRAY_SIZE(buf), buf);
486}
487
488static int ht16k33_led_probe(struct device *dev, struct led_classdev *led,
489			     unsigned int brightness)
490{
491	struct led_init_data init_data = {};
492	int err;
493
494	/* The LED is optional */
495	init_data.fwnode = device_get_named_child_node(dev, "led");
496	if (!init_data.fwnode)
497		return 0;
498
499	init_data.devicename = "auxdisplay";
500	init_data.devname_mandatory = true;
501
502	led->brightness_set_blocking = ht16k33_brightness_set_blocking;
503	led->blink_set = ht16k33_blink_set;
504	led->flags = LED_CORE_SUSPENDRESUME;
505	led->brightness = brightness;
506	led->max_brightness = MAX_BRIGHTNESS;
507
508	err = devm_led_classdev_register_ext(dev, led, &init_data);
509	if (err)
510		dev_err(dev, "Failed to register LED\n");
511
512	return err;
513}
514
515static int ht16k33_keypad_probe(struct i2c_client *client,
516				struct ht16k33_keypad *keypad)
517{
518	struct device *dev = &client->dev;
519	u32 rows = HT16K33_MATRIX_KEYPAD_MAX_ROWS;
520	u32 cols = HT16K33_MATRIX_KEYPAD_MAX_COLS;
521	int err;
522
523	keypad->client = client;
524	init_waitqueue_head(&keypad->wait);
525
526	keypad->dev = devm_input_allocate_device(dev);
527	if (!keypad->dev)
528		return -ENOMEM;
529
530	input_set_drvdata(keypad->dev, keypad);
531
532	keypad->dev->name = DRIVER_NAME"-keypad";
533	keypad->dev->id.bustype = BUS_I2C;
534	keypad->dev->open = ht16k33_keypad_start;
535	keypad->dev->close = ht16k33_keypad_stop;
536
537	if (!device_property_read_bool(dev, "linux,no-autorepeat"))
538		__set_bit(EV_REP, keypad->dev->evbit);
539
540	err = device_property_read_u32(dev, "debounce-delay-ms",
541				       &keypad->debounce_ms);
542	if (err) {
543		dev_err(dev, "key debounce delay not specified\n");
544		return err;
545	}
546
547	err = matrix_keypad_parse_properties(dev, &rows, &cols);
548	if (err)
549		return err;
550	if (rows > HT16K33_MATRIX_KEYPAD_MAX_ROWS ||
551	    cols > HT16K33_MATRIX_KEYPAD_MAX_COLS) {
552		dev_err(dev, "%u rows or %u cols out of range in DT\n", rows,
553			cols);
554		return -ERANGE;
555	}
556
557	keypad->rows = rows;
558	keypad->cols = cols;
559	keypad->row_shift = get_count_order(cols);
560
561	err = matrix_keypad_build_keymap(NULL, NULL, rows, cols, NULL,
562					 keypad->dev);
563	if (err) {
564		dev_err(dev, "failed to build keymap\n");
565		return err;
566	}
567
568	err = devm_request_threaded_irq(dev, client->irq, NULL,
569					ht16k33_keypad_irq_thread,
570					IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
571					DRIVER_NAME, keypad);
572	if (err) {
573		dev_err(dev, "irq request failed %d, error %d\n", client->irq,
574			err);
575		return err;
576	}
577
578	ht16k33_keypad_stop(keypad->dev);
579
580	return input_register_device(keypad->dev);
581}
582
583static int ht16k33_fbdev_probe(struct device *dev, struct ht16k33_priv *priv,
584			       uint32_t brightness)
585{
586	struct ht16k33_fbdev *fbdev = &priv->fbdev;
587	struct backlight_device *bl = NULL;
588	int err;
589
590	if (priv->led.dev) {
591		err = ht16k33_brightness_set(priv, brightness);
592		if (err)
593			return err;
594	} else {
595		/* backwards compatibility with DT lacking an led subnode */
596		struct backlight_properties bl_props;
597
598		memset(&bl_props, 0, sizeof(struct backlight_properties));
599		bl_props.type = BACKLIGHT_RAW;
600		bl_props.max_brightness = MAX_BRIGHTNESS;
601
602		bl = devm_backlight_device_register(dev, DRIVER_NAME"-bl", dev,
603						    priv, &ht16k33_bl_ops,
604						    &bl_props);
605		if (IS_ERR(bl)) {
606			dev_err(dev, "failed to register backlight\n");
607			return PTR_ERR(bl);
608		}
609
610		bl->props.brightness = brightness;
611		ht16k33_bl_update_status(bl);
612	}
613
614	/* Framebuffer (2 bytes per column) */
615	BUILD_BUG_ON(PAGE_SIZE < HT16K33_FB_SIZE);
616	fbdev->buffer = (unsigned char *) get_zeroed_page(GFP_KERNEL);
617	if (!fbdev->buffer)
618		return -ENOMEM;
619
620	fbdev->cache = devm_kmalloc(dev, HT16K33_FB_SIZE, GFP_KERNEL);
621	if (!fbdev->cache) {
622		err = -ENOMEM;
623		goto err_fbdev_buffer;
624	}
625
626	fbdev->info = framebuffer_alloc(0, dev);
627	if (!fbdev->info) {
628		err = -ENOMEM;
629		goto err_fbdev_buffer;
630	}
631
632	err = device_property_read_u32(dev, "refresh-rate-hz",
633				       &fbdev->refresh_rate);
634	if (err) {
635		dev_err(dev, "refresh rate not specified\n");
636		goto err_fbdev_info;
637	}
638	fb_bl_default_curve(fbdev->info, 0, MIN_BRIGHTNESS, MAX_BRIGHTNESS);
639
640	INIT_DELAYED_WORK(&priv->work, ht16k33_fb_update);
641	fbdev->info->fbops = &ht16k33_fb_ops;
642	fbdev->info->flags |= FBINFO_VIRTFB;
643	fbdev->info->screen_buffer = fbdev->buffer;
644	fbdev->info->screen_size = HT16K33_FB_SIZE;
645	fbdev->info->fix = ht16k33_fb_fix;
646	fbdev->info->var = ht16k33_fb_var;
647	fbdev->info->bl_dev = bl;
648	fbdev->info->pseudo_palette = NULL;
 
649	fbdev->info->par = priv;
650
651	err = register_framebuffer(fbdev->info);
652	if (err)
653		goto err_fbdev_info;
654
655	ht16k33_fb_queue(priv);
656	return 0;
657
658err_fbdev_info:
659	framebuffer_release(fbdev->info);
660err_fbdev_buffer:
661	free_page((unsigned long) fbdev->buffer);
662
663	return err;
664}
665
666static int ht16k33_seg_probe(struct device *dev, struct ht16k33_priv *priv,
667			     uint32_t brightness)
668{
669	struct ht16k33_seg *seg = &priv->seg;
670	int err;
671
672	err = ht16k33_brightness_set(priv, brightness);
673	if (err)
674		return err;
675
676	switch (priv->type) {
677	case DISP_MATRIX:
678		/* not handled here */
679		err = -EINVAL;
680		break;
681
682	case DISP_QUAD_7SEG:
683		INIT_DELAYED_WORK(&priv->work, ht16k33_seg7_update);
684		seg->map.seg7 = initial_map_seg7;
685		seg->map_size = sizeof(seg->map.seg7);
686		err = device_create_file(dev, &dev_attr_map_seg7);
687		break;
688
689	case DISP_QUAD_14SEG:
690		INIT_DELAYED_WORK(&priv->work, ht16k33_seg14_update);
691		seg->map.seg14 = initial_map_seg14;
692		seg->map_size = sizeof(seg->map.seg14);
693		err = device_create_file(dev, &dev_attr_map_seg14);
694		break;
695	}
696	if (err)
697		return err;
698
699	err = linedisp_register(&seg->linedisp, dev, 4, seg->curr,
700				ht16k33_linedisp_update);
701	if (err)
702		goto err_remove_map_file;
703
704	return 0;
705
706err_remove_map_file:
707	device_remove_file(dev, &dev_attr_map_seg7);
708	device_remove_file(dev, &dev_attr_map_seg14);
709	return err;
710}
711
712static int ht16k33_probe(struct i2c_client *client)
713{
714	struct device *dev = &client->dev;
715	const struct of_device_id *id;
716	struct ht16k33_priv *priv;
717	uint32_t dft_brightness;
718	int err;
719
720	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
721		dev_err(dev, "i2c_check_functionality error\n");
722		return -EIO;
723	}
724
725	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
726	if (!priv)
727		return -ENOMEM;
728
729	priv->client = client;
730	id = i2c_of_match_device(dev->driver->of_match_table, client);
731	if (id)
732		priv->type = (uintptr_t)id->data;
733	i2c_set_clientdata(client, priv);
734
735	err = ht16k33_initialize(priv);
736	if (err)
737		return err;
738
739	err = device_property_read_u32(dev, "default-brightness-level",
740				       &dft_brightness);
741	if (err) {
742		dft_brightness = MAX_BRIGHTNESS;
743	} else if (dft_brightness > MAX_BRIGHTNESS) {
744		dev_warn(dev,
745			 "invalid default brightness level: %u, using %u\n",
746			 dft_brightness, MAX_BRIGHTNESS);
747		dft_brightness = MAX_BRIGHTNESS;
748	}
749
750	/* LED */
751	err = ht16k33_led_probe(dev, &priv->led, dft_brightness);
752	if (err)
753		return err;
754
755	/* Keypad */
756	if (client->irq > 0) {
757		err = ht16k33_keypad_probe(client, &priv->keypad);
758		if (err)
759			return err;
760	}
761
762	switch (priv->type) {
763	case DISP_MATRIX:
764		/* Frame Buffer Display */
765		err = ht16k33_fbdev_probe(dev, priv, dft_brightness);
766		break;
767
768	case DISP_QUAD_7SEG:
769	case DISP_QUAD_14SEG:
770		/* Segment Display */
771		err = ht16k33_seg_probe(dev, priv, dft_brightness);
772		break;
773	}
774	return err;
775}
776
777static void ht16k33_remove(struct i2c_client *client)
778{
779	struct ht16k33_priv *priv = i2c_get_clientdata(client);
780	struct ht16k33_fbdev *fbdev = &priv->fbdev;
781
782	cancel_delayed_work_sync(&priv->work);
783
784	switch (priv->type) {
785	case DISP_MATRIX:
786		unregister_framebuffer(fbdev->info);
787		framebuffer_release(fbdev->info);
788		free_page((unsigned long)fbdev->buffer);
789		break;
790
791	case DISP_QUAD_7SEG:
792	case DISP_QUAD_14SEG:
793		linedisp_unregister(&priv->seg.linedisp);
794		device_remove_file(&client->dev, &dev_attr_map_seg7);
795		device_remove_file(&client->dev, &dev_attr_map_seg14);
796		break;
797	}
798}
799
800static const struct i2c_device_id ht16k33_i2c_match[] = {
801	{ "ht16k33", 0 },
802	{ }
803};
804MODULE_DEVICE_TABLE(i2c, ht16k33_i2c_match);
805
806static const struct of_device_id ht16k33_of_match[] = {
807	{
808		/* 0.56" 4-Digit 7-Segment FeatherWing Display (Red) */
809		.compatible = "adafruit,3108", .data = (void *)DISP_QUAD_7SEG,
810	}, {
811		/* 0.54" Quad Alphanumeric FeatherWing Display (Red) */
812		.compatible = "adafruit,3130", .data = (void *)DISP_QUAD_14SEG,
813	}, {
814		/* Generic, assumed Dot-Matrix Display */
815		.compatible = "holtek,ht16k33", .data = (void *)DISP_MATRIX,
816	},
817	{ }
818};
819MODULE_DEVICE_TABLE(of, ht16k33_of_match);
820
821static struct i2c_driver ht16k33_driver = {
822	.probe		= ht16k33_probe,
823	.remove		= ht16k33_remove,
824	.driver		= {
825		.name		= DRIVER_NAME,
826		.of_match_table	= ht16k33_of_match,
827	},
828	.id_table = ht16k33_i2c_match,
829};
830module_i2c_driver(ht16k33_driver);
831
832MODULE_DESCRIPTION("Holtek HT16K33 driver");
833MODULE_LICENSE("GPL");
834MODULE_AUTHOR("Robin van der Gracht <robin@protonic.nl>");