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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 <linux/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
63enum display_type {
64 DISP_MATRIX = 0,
65 DISP_QUAD_7SEG,
66 DISP_QUAD_14SEG,
67};
68
69struct 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
82struct ht16k33_fbdev {
83 struct fb_info *info;
84 uint32_t refresh_rate;
85 uint8_t *buffer;
86 uint8_t *cache;
87};
88
89struct 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
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 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
145static int ht16k33_display_off(struct ht16k33_priv *priv)
146{
147 return i2c_smbus_write_byte(priv->client, REG_DISPLAY_SETUP);
148}
149
150static 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
168static 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
176static 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
209static 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 */
219static 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);
256requeue:
257 ht16k33_fb_queue(priv);
258}
259
260static 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
285static 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
293static 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 */
301static int ht16k33_blank(int blank, struct fb_info *info)
302{
303 return 0;
304}
305
306static 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
316static 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 */
328static 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
365static 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
379static 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
390static 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
400static 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
420static 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
435static 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
453static 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
460static const struct linedisp_ops ht16k33_linedisp_ops = {
461 .get_map_type = ht16k33_linedisp_get_map_type,
462 .update = ht16k33_linedisp_update,
463};
464
465static 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 fwnode_handle_put(init_data.fwnode);
487 if (err)
488 dev_err(dev, "Failed to register LED\n");
489
490 return err;
491}
492
493static int ht16k33_keypad_probe(struct i2c_client *client,
494 struct ht16k33_keypad *keypad)
495{
496 struct device *dev = &client->dev;
497 u32 rows = HT16K33_MATRIX_KEYPAD_MAX_ROWS;
498 u32 cols = HT16K33_MATRIX_KEYPAD_MAX_COLS;
499 int err;
500
501 keypad->client = client;
502 init_waitqueue_head(&keypad->wait);
503
504 keypad->dev = devm_input_allocate_device(dev);
505 if (!keypad->dev)
506 return -ENOMEM;
507
508 input_set_drvdata(keypad->dev, keypad);
509
510 keypad->dev->name = DRIVER_NAME"-keypad";
511 keypad->dev->id.bustype = BUS_I2C;
512 keypad->dev->open = ht16k33_keypad_start;
513 keypad->dev->close = ht16k33_keypad_stop;
514
515 if (!device_property_read_bool(dev, "linux,no-autorepeat"))
516 __set_bit(EV_REP, keypad->dev->evbit);
517
518 err = device_property_read_u32(dev, "debounce-delay-ms",
519 &keypad->debounce_ms);
520 if (err) {
521 dev_err(dev, "key debounce delay not specified\n");
522 return err;
523 }
524
525 err = matrix_keypad_parse_properties(dev, &rows, &cols);
526 if (err)
527 return err;
528 if (rows > HT16K33_MATRIX_KEYPAD_MAX_ROWS ||
529 cols > HT16K33_MATRIX_KEYPAD_MAX_COLS) {
530 dev_err(dev, "%u rows or %u cols out of range in DT\n", rows,
531 cols);
532 return -ERANGE;
533 }
534
535 keypad->rows = rows;
536 keypad->cols = cols;
537 keypad->row_shift = get_count_order(cols);
538
539 err = matrix_keypad_build_keymap(NULL, NULL, rows, cols, NULL,
540 keypad->dev);
541 if (err) {
542 dev_err(dev, "failed to build keymap\n");
543 return err;
544 }
545
546 err = devm_request_threaded_irq(dev, client->irq, NULL,
547 ht16k33_keypad_irq_thread,
548 IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
549 DRIVER_NAME, keypad);
550 if (err) {
551 dev_err(dev, "irq request failed %d, error %d\n", client->irq,
552 err);
553 return err;
554 }
555
556 ht16k33_keypad_stop(keypad->dev);
557
558 return input_register_device(keypad->dev);
559}
560
561static int ht16k33_fbdev_probe(struct device *dev, struct ht16k33_priv *priv,
562 uint32_t brightness)
563{
564 struct ht16k33_fbdev *fbdev = &priv->fbdev;
565 struct backlight_device *bl = NULL;
566 int err;
567
568 if (priv->led.dev) {
569 err = ht16k33_brightness_set(priv, brightness);
570 if (err)
571 return err;
572 } else {
573 /* backwards compatibility with DT lacking an led subnode */
574 struct backlight_properties bl_props;
575
576 memset(&bl_props, 0, sizeof(struct backlight_properties));
577 bl_props.type = BACKLIGHT_RAW;
578 bl_props.max_brightness = MAX_BRIGHTNESS;
579
580 bl = devm_backlight_device_register(dev, DRIVER_NAME"-bl", dev,
581 priv, &ht16k33_bl_ops,
582 &bl_props);
583 if (IS_ERR(bl)) {
584 dev_err(dev, "failed to register backlight\n");
585 return PTR_ERR(bl);
586 }
587
588 bl->props.brightness = brightness;
589 ht16k33_bl_update_status(bl);
590 }
591
592 /* Framebuffer (2 bytes per column) */
593 BUILD_BUG_ON(PAGE_SIZE < HT16K33_FB_SIZE);
594 fbdev->buffer = (unsigned char *) get_zeroed_page(GFP_KERNEL);
595 if (!fbdev->buffer)
596 return -ENOMEM;
597
598 fbdev->cache = devm_kmalloc(dev, HT16K33_FB_SIZE, GFP_KERNEL);
599 if (!fbdev->cache) {
600 err = -ENOMEM;
601 goto err_fbdev_buffer;
602 }
603
604 fbdev->info = framebuffer_alloc(0, dev);
605 if (!fbdev->info) {
606 err = -ENOMEM;
607 goto err_fbdev_buffer;
608 }
609
610 err = device_property_read_u32(dev, "refresh-rate-hz",
611 &fbdev->refresh_rate);
612 if (err) {
613 dev_err(dev, "refresh rate not specified\n");
614 goto err_fbdev_info;
615 }
616 fb_bl_default_curve(fbdev->info, 0, MIN_BRIGHTNESS, MAX_BRIGHTNESS);
617
618 INIT_DELAYED_WORK(&priv->work, ht16k33_fb_update);
619 fbdev->info->fbops = &ht16k33_fb_ops;
620 fbdev->info->flags |= FBINFO_VIRTFB;
621 fbdev->info->screen_buffer = fbdev->buffer;
622 fbdev->info->screen_size = HT16K33_FB_SIZE;
623 fbdev->info->fix = ht16k33_fb_fix;
624 fbdev->info->var = ht16k33_fb_var;
625 fbdev->info->bl_dev = bl;
626 fbdev->info->pseudo_palette = NULL;
627 fbdev->info->par = priv;
628
629 err = register_framebuffer(fbdev->info);
630 if (err)
631 goto err_fbdev_info;
632
633 ht16k33_fb_queue(priv);
634 return 0;
635
636err_fbdev_info:
637 framebuffer_release(fbdev->info);
638err_fbdev_buffer:
639 free_page((unsigned long) fbdev->buffer);
640
641 return err;
642}
643
644static int ht16k33_seg_probe(struct device *dev, struct ht16k33_priv *priv,
645 uint32_t brightness)
646{
647 struct linedisp *linedisp = &priv->linedisp;
648 int err;
649
650 err = ht16k33_brightness_set(priv, brightness);
651 if (err)
652 return err;
653
654 return linedisp_register(linedisp, dev, 4, &ht16k33_linedisp_ops);
655}
656
657static int ht16k33_probe(struct i2c_client *client)
658{
659 struct device *dev = &client->dev;
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 priv->type = (uintptr_t)i2c_get_match_data(client);
675
676 i2c_set_clientdata(client, priv);
677
678 err = ht16k33_initialize(priv);
679 if (err)
680 return err;
681
682 err = device_property_read_u32(dev, "default-brightness-level",
683 &dft_brightness);
684 if (err) {
685 dft_brightness = MAX_BRIGHTNESS;
686 } else if (dft_brightness > MAX_BRIGHTNESS) {
687 dev_warn(dev,
688 "invalid default brightness level: %u, using %u\n",
689 dft_brightness, MAX_BRIGHTNESS);
690 dft_brightness = MAX_BRIGHTNESS;
691 }
692
693 /* LED */
694 err = ht16k33_led_probe(dev, &priv->led, dft_brightness);
695 if (err)
696 return err;
697
698 /* Keypad */
699 if (client->irq > 0) {
700 err = ht16k33_keypad_probe(client, &priv->keypad);
701 if (err)
702 return err;
703 }
704
705 switch (priv->type) {
706 case DISP_MATRIX:
707 /* Frame Buffer Display */
708 err = ht16k33_fbdev_probe(dev, priv, dft_brightness);
709 break;
710
711 case DISP_QUAD_7SEG:
712 case DISP_QUAD_14SEG:
713 /* Segment Display */
714 err = ht16k33_seg_probe(dev, priv, dft_brightness);
715 break;
716
717 default:
718 return -EINVAL;
719 }
720 return err;
721}
722
723static void ht16k33_remove(struct i2c_client *client)
724{
725 struct ht16k33_priv *priv = i2c_get_clientdata(client);
726 struct ht16k33_fbdev *fbdev = &priv->fbdev;
727
728 cancel_delayed_work_sync(&priv->work);
729
730 switch (priv->type) {
731 case DISP_MATRIX:
732 unregister_framebuffer(fbdev->info);
733 framebuffer_release(fbdev->info);
734 free_page((unsigned long)fbdev->buffer);
735 break;
736
737 case DISP_QUAD_7SEG:
738 case DISP_QUAD_14SEG:
739 linedisp_unregister(&priv->linedisp);
740 break;
741
742 default:
743 break;
744 }
745}
746
747static const struct i2c_device_id ht16k33_i2c_match[] = {
748 { "3108", DISP_QUAD_7SEG },
749 { "3130", DISP_QUAD_14SEG },
750 { "ht16k33", DISP_MATRIX },
751 { }
752};
753MODULE_DEVICE_TABLE(i2c, ht16k33_i2c_match);
754
755static const struct of_device_id ht16k33_of_match[] = {
756 {
757 /* 0.56" 4-Digit 7-Segment FeatherWing Display (Red) */
758 .compatible = "adafruit,3108", .data = (void *)DISP_QUAD_7SEG,
759 }, {
760 /* 0.54" Quad Alphanumeric FeatherWing Display (Red) */
761 .compatible = "adafruit,3130", .data = (void *)DISP_QUAD_14SEG,
762 }, {
763 /* Generic, assumed Dot-Matrix Display */
764 .compatible = "holtek,ht16k33", .data = (void *)DISP_MATRIX,
765 },
766 { }
767};
768MODULE_DEVICE_TABLE(of, ht16k33_of_match);
769
770static struct i2c_driver ht16k33_driver = {
771 .probe = ht16k33_probe,
772 .remove = ht16k33_remove,
773 .driver = {
774 .name = DRIVER_NAME,
775 .of_match_table = ht16k33_of_match,
776 },
777 .id_table = ht16k33_i2c_match,
778};
779module_i2c_driver(ht16k33_driver);
780
781MODULE_DESCRIPTION("Holtek HT16K33 driver");
782MODULE_LICENSE("GPL");
783MODULE_IMPORT_NS("LINEDISP");
784MODULE_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 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>");