Loading...
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>");
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 */
9
10#include <linux/kernel.h>
11#include <linux/module.h>
12#include <linux/interrupt.h>
13#include <linux/i2c.h>
14#include <linux/of.h>
15#include <linux/fb.h>
16#include <linux/slab.h>
17#include <linux/backlight.h>
18#include <linux/input.h>
19#include <linux/input/matrix_keypad.h>
20#include <linux/workqueue.h>
21#include <linux/mm.h>
22
23/* Registers */
24#define REG_SYSTEM_SETUP 0x20
25#define REG_SYSTEM_SETUP_OSC_ON BIT(0)
26
27#define REG_DISPLAY_SETUP 0x80
28#define REG_DISPLAY_SETUP_ON BIT(0)
29
30#define REG_ROWINT_SET 0xA0
31#define REG_ROWINT_SET_INT_EN BIT(0)
32#define REG_ROWINT_SET_INT_ACT_HIGH BIT(1)
33
34#define REG_BRIGHTNESS 0xE0
35
36/* Defines */
37#define DRIVER_NAME "ht16k33"
38
39#define MIN_BRIGHTNESS 0x1
40#define MAX_BRIGHTNESS 0x10
41
42#define HT16K33_MATRIX_LED_MAX_COLS 8
43#define HT16K33_MATRIX_LED_MAX_ROWS 16
44#define HT16K33_MATRIX_KEYPAD_MAX_COLS 3
45#define HT16K33_MATRIX_KEYPAD_MAX_ROWS 12
46
47#define BYTES_PER_ROW (HT16K33_MATRIX_LED_MAX_ROWS / 8)
48#define HT16K33_FB_SIZE (HT16K33_MATRIX_LED_MAX_COLS * BYTES_PER_ROW)
49
50struct ht16k33_keypad {
51 struct i2c_client *client;
52 struct input_dev *dev;
53 uint32_t cols;
54 uint32_t rows;
55 uint32_t row_shift;
56 uint32_t debounce_ms;
57 uint16_t last_key_state[HT16K33_MATRIX_KEYPAD_MAX_COLS];
58
59 wait_queue_head_t wait;
60 bool stopped;
61};
62
63struct ht16k33_fbdev {
64 struct fb_info *info;
65 uint32_t refresh_rate;
66 uint8_t *buffer;
67 uint8_t *cache;
68 struct delayed_work work;
69};
70
71struct ht16k33_priv {
72 struct i2c_client *client;
73 struct ht16k33_keypad keypad;
74 struct ht16k33_fbdev fbdev;
75};
76
77static const struct fb_fix_screeninfo ht16k33_fb_fix = {
78 .id = DRIVER_NAME,
79 .type = FB_TYPE_PACKED_PIXELS,
80 .visual = FB_VISUAL_MONO10,
81 .xpanstep = 0,
82 .ypanstep = 0,
83 .ywrapstep = 0,
84 .line_length = HT16K33_MATRIX_LED_MAX_ROWS,
85 .accel = FB_ACCEL_NONE,
86};
87
88static const struct fb_var_screeninfo ht16k33_fb_var = {
89 .xres = HT16K33_MATRIX_LED_MAX_ROWS,
90 .yres = HT16K33_MATRIX_LED_MAX_COLS,
91 .xres_virtual = HT16K33_MATRIX_LED_MAX_ROWS,
92 .yres_virtual = HT16K33_MATRIX_LED_MAX_COLS,
93 .bits_per_pixel = 1,
94 .red = { 0, 1, 0 },
95 .green = { 0, 1, 0 },
96 .blue = { 0, 1, 0 },
97 .left_margin = 0,
98 .right_margin = 0,
99 .upper_margin = 0,
100 .lower_margin = 0,
101 .vmode = FB_VMODE_NONINTERLACED,
102};
103
104static int ht16k33_display_on(struct ht16k33_priv *priv)
105{
106 uint8_t data = REG_DISPLAY_SETUP | REG_DISPLAY_SETUP_ON;
107
108 return i2c_smbus_write_byte(priv->client, data);
109}
110
111static int ht16k33_display_off(struct ht16k33_priv *priv)
112{
113 return i2c_smbus_write_byte(priv->client, REG_DISPLAY_SETUP);
114}
115
116static void ht16k33_fb_queue(struct ht16k33_priv *priv)
117{
118 struct ht16k33_fbdev *fbdev = &priv->fbdev;
119
120 schedule_delayed_work(&fbdev->work,
121 msecs_to_jiffies(HZ / fbdev->refresh_rate));
122}
123
124/*
125 * This gets the fb data from cache and copies it to ht16k33 display RAM
126 */
127static void ht16k33_fb_update(struct work_struct *work)
128{
129 struct ht16k33_fbdev *fbdev =
130 container_of(work, struct ht16k33_fbdev, work.work);
131 struct ht16k33_priv *priv =
132 container_of(fbdev, struct ht16k33_priv, fbdev);
133
134 uint8_t *p1, *p2;
135 int len, pos = 0, first = -1;
136
137 p1 = fbdev->cache;
138 p2 = fbdev->buffer;
139
140 /* Search for the first byte with changes */
141 while (pos < HT16K33_FB_SIZE && first < 0) {
142 if (*(p1++) - *(p2++))
143 first = pos;
144 pos++;
145 }
146
147 /* No changes found */
148 if (first < 0)
149 goto requeue;
150
151 len = HT16K33_FB_SIZE - first;
152 p1 = fbdev->cache + HT16K33_FB_SIZE - 1;
153 p2 = fbdev->buffer + HT16K33_FB_SIZE - 1;
154
155 /* Determine i2c transfer length */
156 while (len > 1) {
157 if (*(p1--) - *(p2--))
158 break;
159 len--;
160 }
161
162 p1 = fbdev->cache + first;
163 p2 = fbdev->buffer + first;
164 if (!i2c_smbus_write_i2c_block_data(priv->client, first, len, p2))
165 memcpy(p1, p2, len);
166requeue:
167 ht16k33_fb_queue(priv);
168}
169
170static int ht16k33_initialize(struct ht16k33_priv *priv)
171{
172 uint8_t byte;
173 int err;
174 uint8_t data[HT16K33_MATRIX_LED_MAX_COLS * 2];
175
176 /* Clear RAM (8 * 16 bits) */
177 memset(data, 0, sizeof(data));
178 err = i2c_smbus_write_block_data(priv->client, 0, sizeof(data), data);
179 if (err)
180 return err;
181
182 /* Turn on internal oscillator */
183 byte = REG_SYSTEM_SETUP_OSC_ON | REG_SYSTEM_SETUP;
184 err = i2c_smbus_write_byte(priv->client, byte);
185 if (err)
186 return err;
187
188 /* Configure INT pin */
189 byte = REG_ROWINT_SET | REG_ROWINT_SET_INT_ACT_HIGH;
190 if (priv->client->irq > 0)
191 byte |= REG_ROWINT_SET_INT_EN;
192 return i2c_smbus_write_byte(priv->client, byte);
193}
194
195static int ht16k33_bl_update_status(struct backlight_device *bl)
196{
197 int brightness = bl->props.brightness;
198 struct ht16k33_priv *priv = bl_get_data(bl);
199
200 if (bl->props.power != FB_BLANK_UNBLANK ||
201 bl->props.fb_blank != FB_BLANK_UNBLANK ||
202 bl->props.state & BL_CORE_FBBLANK || brightness == 0) {
203 return ht16k33_display_off(priv);
204 }
205
206 ht16k33_display_on(priv);
207 return i2c_smbus_write_byte(priv->client,
208 REG_BRIGHTNESS | (brightness - 1));
209}
210
211static int ht16k33_bl_check_fb(struct backlight_device *bl, struct fb_info *fi)
212{
213 struct ht16k33_priv *priv = bl_get_data(bl);
214
215 return (fi == NULL) || (fi->par == priv);
216}
217
218static const struct backlight_ops ht16k33_bl_ops = {
219 .update_status = ht16k33_bl_update_status,
220 .check_fb = ht16k33_bl_check_fb,
221};
222
223static int ht16k33_mmap(struct fb_info *info, struct vm_area_struct *vma)
224{
225 struct ht16k33_priv *priv = info->par;
226 struct page *pages = virt_to_page(priv->fbdev.buffer);
227
228 return vm_map_pages_zero(vma, &pages, 1);
229}
230
231static const struct fb_ops ht16k33_fb_ops = {
232 .owner = THIS_MODULE,
233 .fb_read = fb_sys_read,
234 .fb_write = fb_sys_write,
235 .fb_fillrect = sys_fillrect,
236 .fb_copyarea = sys_copyarea,
237 .fb_imageblit = sys_imageblit,
238 .fb_mmap = ht16k33_mmap,
239};
240
241/*
242 * This gets the keys from keypad and reports it to input subsystem.
243 * Returns true if a key is pressed.
244 */
245static bool ht16k33_keypad_scan(struct ht16k33_keypad *keypad)
246{
247 const unsigned short *keycodes = keypad->dev->keycode;
248 u16 new_state[HT16K33_MATRIX_KEYPAD_MAX_COLS];
249 __le16 data[HT16K33_MATRIX_KEYPAD_MAX_COLS];
250 unsigned long bits_changed;
251 int row, col, code;
252 int rc;
253 bool pressed = false;
254
255 rc = i2c_smbus_read_i2c_block_data(keypad->client, 0x40,
256 sizeof(data), (u8 *)data);
257 if (rc != sizeof(data)) {
258 dev_err(&keypad->client->dev,
259 "Failed to read key data, rc=%d\n", rc);
260 return false;
261 }
262
263 for (col = 0; col < keypad->cols; col++) {
264 new_state[col] = le16_to_cpu(data[col]);
265 if (new_state[col])
266 pressed = true;
267 bits_changed = keypad->last_key_state[col] ^ new_state[col];
268
269 for_each_set_bit(row, &bits_changed, BITS_PER_LONG) {
270 code = MATRIX_SCAN_CODE(row, col, keypad->row_shift);
271 input_event(keypad->dev, EV_MSC, MSC_SCAN, code);
272 input_report_key(keypad->dev, keycodes[code],
273 new_state[col] & BIT(row));
274 }
275 }
276 input_sync(keypad->dev);
277 memcpy(keypad->last_key_state, new_state, sizeof(u16) * keypad->cols);
278
279 return pressed;
280}
281
282static irqreturn_t ht16k33_keypad_irq_thread(int irq, void *dev)
283{
284 struct ht16k33_keypad *keypad = dev;
285
286 do {
287 wait_event_timeout(keypad->wait, keypad->stopped,
288 msecs_to_jiffies(keypad->debounce_ms));
289 if (keypad->stopped)
290 break;
291 } while (ht16k33_keypad_scan(keypad));
292
293 return IRQ_HANDLED;
294}
295
296static int ht16k33_keypad_start(struct input_dev *dev)
297{
298 struct ht16k33_keypad *keypad = input_get_drvdata(dev);
299
300 keypad->stopped = false;
301 mb();
302 enable_irq(keypad->client->irq);
303
304 return 0;
305}
306
307static void ht16k33_keypad_stop(struct input_dev *dev)
308{
309 struct ht16k33_keypad *keypad = input_get_drvdata(dev);
310
311 keypad->stopped = true;
312 mb();
313 wake_up(&keypad->wait);
314 disable_irq(keypad->client->irq);
315}
316
317static int ht16k33_keypad_probe(struct i2c_client *client,
318 struct ht16k33_keypad *keypad)
319{
320 struct device_node *node = client->dev.of_node;
321 u32 rows = HT16K33_MATRIX_KEYPAD_MAX_ROWS;
322 u32 cols = HT16K33_MATRIX_KEYPAD_MAX_COLS;
323 int err;
324
325 keypad->client = client;
326 init_waitqueue_head(&keypad->wait);
327
328 keypad->dev = devm_input_allocate_device(&client->dev);
329 if (!keypad->dev)
330 return -ENOMEM;
331
332 input_set_drvdata(keypad->dev, keypad);
333
334 keypad->dev->name = DRIVER_NAME"-keypad";
335 keypad->dev->id.bustype = BUS_I2C;
336 keypad->dev->open = ht16k33_keypad_start;
337 keypad->dev->close = ht16k33_keypad_stop;
338
339 if (!of_get_property(node, "linux,no-autorepeat", NULL))
340 __set_bit(EV_REP, keypad->dev->evbit);
341
342 err = of_property_read_u32(node, "debounce-delay-ms",
343 &keypad->debounce_ms);
344 if (err) {
345 dev_err(&client->dev, "key debounce delay not specified\n");
346 return err;
347 }
348
349 err = matrix_keypad_parse_of_params(&client->dev, &rows, &cols);
350 if (err)
351 return err;
352 if (rows > HT16K33_MATRIX_KEYPAD_MAX_ROWS ||
353 cols > HT16K33_MATRIX_KEYPAD_MAX_COLS) {
354 dev_err(&client->dev, "%u rows or %u cols out of range in DT\n",
355 rows, cols);
356 return -ERANGE;
357 }
358
359 keypad->rows = rows;
360 keypad->cols = cols;
361 keypad->row_shift = get_count_order(cols);
362
363 err = matrix_keypad_build_keymap(NULL, NULL, rows, cols, NULL,
364 keypad->dev);
365 if (err) {
366 dev_err(&client->dev, "failed to build keymap\n");
367 return err;
368 }
369
370 err = devm_request_threaded_irq(&client->dev, client->irq,
371 NULL, ht16k33_keypad_irq_thread,
372 IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
373 DRIVER_NAME, keypad);
374 if (err) {
375 dev_err(&client->dev, "irq request failed %d, error %d\n",
376 client->irq, err);
377 return err;
378 }
379
380 ht16k33_keypad_stop(keypad->dev);
381
382 err = input_register_device(keypad->dev);
383 if (err)
384 return err;
385
386 return 0;
387}
388
389static int ht16k33_probe(struct i2c_client *client,
390 const struct i2c_device_id *id)
391{
392 int err;
393 uint32_t dft_brightness;
394 struct backlight_device *bl;
395 struct backlight_properties bl_props;
396 struct ht16k33_priv *priv;
397 struct ht16k33_fbdev *fbdev;
398 struct device_node *node = client->dev.of_node;
399
400 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
401 dev_err(&client->dev, "i2c_check_functionality error\n");
402 return -EIO;
403 }
404
405 if (client->irq <= 0) {
406 dev_err(&client->dev, "No IRQ specified\n");
407 return -EINVAL;
408 }
409
410 priv = devm_kzalloc(&client->dev, sizeof(*priv), GFP_KERNEL);
411 if (!priv)
412 return -ENOMEM;
413
414 priv->client = client;
415 i2c_set_clientdata(client, priv);
416 fbdev = &priv->fbdev;
417
418 err = ht16k33_initialize(priv);
419 if (err)
420 return err;
421
422 /* Framebuffer (2 bytes per column) */
423 BUILD_BUG_ON(PAGE_SIZE < HT16K33_FB_SIZE);
424 fbdev->buffer = (unsigned char *) get_zeroed_page(GFP_KERNEL);
425 if (!fbdev->buffer)
426 return -ENOMEM;
427
428 fbdev->cache = devm_kmalloc(&client->dev, HT16K33_FB_SIZE, GFP_KERNEL);
429 if (!fbdev->cache) {
430 err = -ENOMEM;
431 goto err_fbdev_buffer;
432 }
433
434 fbdev->info = framebuffer_alloc(0, &client->dev);
435 if (!fbdev->info) {
436 err = -ENOMEM;
437 goto err_fbdev_buffer;
438 }
439
440 err = of_property_read_u32(node, "refresh-rate-hz",
441 &fbdev->refresh_rate);
442 if (err) {
443 dev_err(&client->dev, "refresh rate not specified\n");
444 goto err_fbdev_info;
445 }
446 fb_bl_default_curve(fbdev->info, 0, MIN_BRIGHTNESS, MAX_BRIGHTNESS);
447
448 INIT_DELAYED_WORK(&fbdev->work, ht16k33_fb_update);
449 fbdev->info->fbops = &ht16k33_fb_ops;
450 fbdev->info->screen_base = (char __iomem *) fbdev->buffer;
451 fbdev->info->screen_size = HT16K33_FB_SIZE;
452 fbdev->info->fix = ht16k33_fb_fix;
453 fbdev->info->var = ht16k33_fb_var;
454 fbdev->info->pseudo_palette = NULL;
455 fbdev->info->flags = FBINFO_FLAG_DEFAULT;
456 fbdev->info->par = priv;
457
458 err = register_framebuffer(fbdev->info);
459 if (err)
460 goto err_fbdev_info;
461
462 err = ht16k33_keypad_probe(client, &priv->keypad);
463 if (err)
464 goto err_fbdev_unregister;
465
466 /* Backlight */
467 memset(&bl_props, 0, sizeof(struct backlight_properties));
468 bl_props.type = BACKLIGHT_RAW;
469 bl_props.max_brightness = MAX_BRIGHTNESS;
470
471 bl = devm_backlight_device_register(&client->dev, DRIVER_NAME"-bl",
472 &client->dev, priv,
473 &ht16k33_bl_ops, &bl_props);
474 if (IS_ERR(bl)) {
475 dev_err(&client->dev, "failed to register backlight\n");
476 err = PTR_ERR(bl);
477 goto err_fbdev_unregister;
478 }
479
480 err = of_property_read_u32(node, "default-brightness-level",
481 &dft_brightness);
482 if (err) {
483 dft_brightness = MAX_BRIGHTNESS;
484 } else if (dft_brightness > MAX_BRIGHTNESS) {
485 dev_warn(&client->dev,
486 "invalid default brightness level: %u, using %u\n",
487 dft_brightness, MAX_BRIGHTNESS);
488 dft_brightness = MAX_BRIGHTNESS;
489 }
490
491 bl->props.brightness = dft_brightness;
492 ht16k33_bl_update_status(bl);
493
494 ht16k33_fb_queue(priv);
495 return 0;
496
497err_fbdev_unregister:
498 unregister_framebuffer(fbdev->info);
499err_fbdev_info:
500 framebuffer_release(fbdev->info);
501err_fbdev_buffer:
502 free_page((unsigned long) fbdev->buffer);
503
504 return err;
505}
506
507static int ht16k33_remove(struct i2c_client *client)
508{
509 struct ht16k33_priv *priv = i2c_get_clientdata(client);
510 struct ht16k33_fbdev *fbdev = &priv->fbdev;
511
512 cancel_delayed_work_sync(&fbdev->work);
513 unregister_framebuffer(fbdev->info);
514 framebuffer_release(fbdev->info);
515 free_page((unsigned long) fbdev->buffer);
516
517 return 0;
518}
519
520static const struct i2c_device_id ht16k33_i2c_match[] = {
521 { "ht16k33", 0 },
522 { }
523};
524MODULE_DEVICE_TABLE(i2c, ht16k33_i2c_match);
525
526static const struct of_device_id ht16k33_of_match[] = {
527 { .compatible = "holtek,ht16k33", },
528 { }
529};
530MODULE_DEVICE_TABLE(of, ht16k33_of_match);
531
532static struct i2c_driver ht16k33_driver = {
533 .probe = ht16k33_probe,
534 .remove = ht16k33_remove,
535 .driver = {
536 .name = DRIVER_NAME,
537 .of_match_table = of_match_ptr(ht16k33_of_match),
538 },
539 .id_table = ht16k33_i2c_match,
540};
541module_i2c_driver(ht16k33_driver);
542
543MODULE_DESCRIPTION("Holtek HT16K33 driver");
544MODULE_LICENSE("GPL");
545MODULE_AUTHOR("Robin van der Gracht <robin@protonic.nl>");