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/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/*
2 * HT16K33 driver
3 *
4 * Author: Robin van der Gracht <robin@protonic.nl>
5 *
6 * Copyright: (C) 2016 Protonic Holland.
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 *
12 * This program is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * General Public License for more details.
16 */
17
18#include <linux/kernel.h>
19#include <linux/module.h>
20#include <linux/interrupt.h>
21#include <linux/i2c.h>
22#include <linux/of.h>
23#include <linux/fb.h>
24#include <linux/slab.h>
25#include <linux/backlight.h>
26#include <linux/input.h>
27#include <linux/input/matrix_keypad.h>
28#include <linux/workqueue.h>
29#include <linux/mm.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
38#define REG_ROWINT_SET 0xA0
39#define REG_ROWINT_SET_INT_EN BIT(0)
40#define REG_ROWINT_SET_INT_ACT_HIGH BIT(1)
41
42#define REG_BRIGHTNESS 0xE0
43
44/* Defines */
45#define DRIVER_NAME "ht16k33"
46
47#define MIN_BRIGHTNESS 0x1
48#define MAX_BRIGHTNESS 0x10
49
50#define HT16K33_MATRIX_LED_MAX_COLS 8
51#define HT16K33_MATRIX_LED_MAX_ROWS 16
52#define HT16K33_MATRIX_KEYPAD_MAX_COLS 3
53#define HT16K33_MATRIX_KEYPAD_MAX_ROWS 12
54
55#define BYTES_PER_ROW (HT16K33_MATRIX_LED_MAX_ROWS / 8)
56#define HT16K33_FB_SIZE (HT16K33_MATRIX_LED_MAX_COLS * BYTES_PER_ROW)
57
58struct ht16k33_keypad {
59 struct i2c_client *client;
60 struct input_dev *dev;
61 uint32_t cols;
62 uint32_t rows;
63 uint32_t row_shift;
64 uint32_t debounce_ms;
65 uint16_t last_key_state[HT16K33_MATRIX_KEYPAD_MAX_COLS];
66
67 wait_queue_head_t wait;
68 bool stopped;
69};
70
71struct ht16k33_fbdev {
72 struct fb_info *info;
73 uint32_t refresh_rate;
74 uint8_t *buffer;
75 uint8_t *cache;
76 struct delayed_work work;
77};
78
79struct ht16k33_priv {
80 struct i2c_client *client;
81 struct ht16k33_keypad keypad;
82 struct ht16k33_fbdev fbdev;
83};
84
85static struct fb_fix_screeninfo ht16k33_fb_fix = {
86 .id = DRIVER_NAME,
87 .type = FB_TYPE_PACKED_PIXELS,
88 .visual = FB_VISUAL_MONO10,
89 .xpanstep = 0,
90 .ypanstep = 0,
91 .ywrapstep = 0,
92 .line_length = HT16K33_MATRIX_LED_MAX_ROWS,
93 .accel = FB_ACCEL_NONE,
94};
95
96static struct fb_var_screeninfo ht16k33_fb_var = {
97 .xres = HT16K33_MATRIX_LED_MAX_ROWS,
98 .yres = HT16K33_MATRIX_LED_MAX_COLS,
99 .xres_virtual = HT16K33_MATRIX_LED_MAX_ROWS,
100 .yres_virtual = HT16K33_MATRIX_LED_MAX_COLS,
101 .bits_per_pixel = 1,
102 .red = { 0, 1, 0 },
103 .green = { 0, 1, 0 },
104 .blue = { 0, 1, 0 },
105 .left_margin = 0,
106 .right_margin = 0,
107 .upper_margin = 0,
108 .lower_margin = 0,
109 .vmode = FB_VMODE_NONINTERLACED,
110};
111
112static int ht16k33_display_on(struct ht16k33_priv *priv)
113{
114 uint8_t data = REG_DISPLAY_SETUP | REG_DISPLAY_SETUP_ON;
115
116 return i2c_smbus_write_byte(priv->client, data);
117}
118
119static int ht16k33_display_off(struct ht16k33_priv *priv)
120{
121 return i2c_smbus_write_byte(priv->client, REG_DISPLAY_SETUP);
122}
123
124static void ht16k33_fb_queue(struct ht16k33_priv *priv)
125{
126 struct ht16k33_fbdev *fbdev = &priv->fbdev;
127
128 schedule_delayed_work(&fbdev->work,
129 msecs_to_jiffies(HZ / fbdev->refresh_rate));
130}
131
132/*
133 * This gets the fb data from cache and copies it to ht16k33 display RAM
134 */
135static void ht16k33_fb_update(struct work_struct *work)
136{
137 struct ht16k33_fbdev *fbdev =
138 container_of(work, struct ht16k33_fbdev, work.work);
139 struct ht16k33_priv *priv =
140 container_of(fbdev, struct ht16k33_priv, fbdev);
141
142 uint8_t *p1, *p2;
143 int len, pos = 0, first = -1;
144
145 p1 = fbdev->cache;
146 p2 = fbdev->buffer;
147
148 /* Search for the first byte with changes */
149 while (pos < HT16K33_FB_SIZE && first < 0) {
150 if (*(p1++) - *(p2++))
151 first = pos;
152 pos++;
153 }
154
155 /* No changes found */
156 if (first < 0)
157 goto requeue;
158
159 len = HT16K33_FB_SIZE - first;
160 p1 = fbdev->cache + HT16K33_FB_SIZE - 1;
161 p2 = fbdev->buffer + HT16K33_FB_SIZE - 1;
162
163 /* Determine i2c transfer length */
164 while (len > 1) {
165 if (*(p1--) - *(p2--))
166 break;
167 len--;
168 }
169
170 p1 = fbdev->cache + first;
171 p2 = fbdev->buffer + first;
172 if (!i2c_smbus_write_i2c_block_data(priv->client, first, len, p2))
173 memcpy(p1, p2, len);
174requeue:
175 ht16k33_fb_queue(priv);
176}
177
178static int ht16k33_initialize(struct ht16k33_priv *priv)
179{
180 uint8_t byte;
181 int err;
182 uint8_t data[HT16K33_MATRIX_LED_MAX_COLS * 2];
183
184 /* Clear RAM (8 * 16 bits) */
185 memset(data, 0, sizeof(data));
186 err = i2c_smbus_write_block_data(priv->client, 0, sizeof(data), data);
187 if (err)
188 return err;
189
190 /* Turn on internal oscillator */
191 byte = REG_SYSTEM_SETUP_OSC_ON | REG_SYSTEM_SETUP;
192 err = i2c_smbus_write_byte(priv->client, byte);
193 if (err)
194 return err;
195
196 /* Configure INT pin */
197 byte = REG_ROWINT_SET | REG_ROWINT_SET_INT_ACT_HIGH;
198 if (priv->client->irq > 0)
199 byte |= REG_ROWINT_SET_INT_EN;
200 return i2c_smbus_write_byte(priv->client, byte);
201}
202
203static int ht16k33_bl_update_status(struct backlight_device *bl)
204{
205 int brightness = bl->props.brightness;
206 struct ht16k33_priv *priv = bl_get_data(bl);
207
208 if (bl->props.power != FB_BLANK_UNBLANK ||
209 bl->props.fb_blank != FB_BLANK_UNBLANK ||
210 bl->props.state & BL_CORE_FBBLANK || brightness == 0) {
211 return ht16k33_display_off(priv);
212 }
213
214 ht16k33_display_on(priv);
215 return i2c_smbus_write_byte(priv->client,
216 REG_BRIGHTNESS | (brightness - 1));
217}
218
219static int ht16k33_bl_check_fb(struct backlight_device *bl, struct fb_info *fi)
220{
221 struct ht16k33_priv *priv = bl_get_data(bl);
222
223 return (fi == NULL) || (fi->par == priv);
224}
225
226static const struct backlight_ops ht16k33_bl_ops = {
227 .update_status = ht16k33_bl_update_status,
228 .check_fb = ht16k33_bl_check_fb,
229};
230
231static int ht16k33_mmap(struct fb_info *info, struct vm_area_struct *vma)
232{
233 struct ht16k33_priv *priv = info->par;
234
235 return vm_insert_page(vma, vma->vm_start,
236 virt_to_page(priv->fbdev.buffer));
237}
238
239static struct fb_ops ht16k33_fb_ops = {
240 .owner = THIS_MODULE,
241 .fb_read = fb_sys_read,
242 .fb_write = fb_sys_write,
243 .fb_fillrect = sys_fillrect,
244 .fb_copyarea = sys_copyarea,
245 .fb_imageblit = sys_imageblit,
246 .fb_mmap = ht16k33_mmap,
247};
248
249/*
250 * This gets the keys from keypad and reports it to input subsystem.
251 * Returns true if a key is pressed.
252 */
253static bool ht16k33_keypad_scan(struct ht16k33_keypad *keypad)
254{
255 const unsigned short *keycodes = keypad->dev->keycode;
256 u16 new_state[HT16K33_MATRIX_KEYPAD_MAX_COLS];
257 __le16 data[HT16K33_MATRIX_KEYPAD_MAX_COLS];
258 unsigned long bits_changed;
259 int row, col, code;
260 int rc;
261 bool pressed = false;
262
263 rc = i2c_smbus_read_i2c_block_data(keypad->client, 0x40,
264 sizeof(data), (u8 *)data);
265 if (rc != sizeof(data)) {
266 dev_err(&keypad->client->dev,
267 "Failed to read key data, rc=%d\n", rc);
268 return false;
269 }
270
271 for (col = 0; col < keypad->cols; col++) {
272 new_state[col] = le16_to_cpu(data[col]);
273 if (new_state[col])
274 pressed = true;
275 bits_changed = keypad->last_key_state[col] ^ new_state[col];
276
277 for_each_set_bit(row, &bits_changed, BITS_PER_LONG) {
278 code = MATRIX_SCAN_CODE(row, col, keypad->row_shift);
279 input_event(keypad->dev, EV_MSC, MSC_SCAN, code);
280 input_report_key(keypad->dev, keycodes[code],
281 new_state[col] & BIT(row));
282 }
283 }
284 input_sync(keypad->dev);
285 memcpy(keypad->last_key_state, new_state, sizeof(u16) * keypad->cols);
286
287 return pressed;
288}
289
290static irqreturn_t ht16k33_keypad_irq_thread(int irq, void *dev)
291{
292 struct ht16k33_keypad *keypad = dev;
293
294 do {
295 wait_event_timeout(keypad->wait, keypad->stopped,
296 msecs_to_jiffies(keypad->debounce_ms));
297 if (keypad->stopped)
298 break;
299 } while (ht16k33_keypad_scan(keypad));
300
301 return IRQ_HANDLED;
302}
303
304static int ht16k33_keypad_start(struct input_dev *dev)
305{
306 struct ht16k33_keypad *keypad = input_get_drvdata(dev);
307
308 keypad->stopped = false;
309 mb();
310 enable_irq(keypad->client->irq);
311
312 return 0;
313}
314
315static void ht16k33_keypad_stop(struct input_dev *dev)
316{
317 struct ht16k33_keypad *keypad = input_get_drvdata(dev);
318
319 keypad->stopped = true;
320 mb();
321 wake_up(&keypad->wait);
322 disable_irq(keypad->client->irq);
323}
324
325static int ht16k33_keypad_probe(struct i2c_client *client,
326 struct ht16k33_keypad *keypad)
327{
328 struct device_node *node = client->dev.of_node;
329 u32 rows = HT16K33_MATRIX_KEYPAD_MAX_ROWS;
330 u32 cols = HT16K33_MATRIX_KEYPAD_MAX_COLS;
331 int err;
332
333 keypad->client = client;
334 init_waitqueue_head(&keypad->wait);
335
336 keypad->dev = devm_input_allocate_device(&client->dev);
337 if (!keypad->dev)
338 return -ENOMEM;
339
340 input_set_drvdata(keypad->dev, keypad);
341
342 keypad->dev->name = DRIVER_NAME"-keypad";
343 keypad->dev->id.bustype = BUS_I2C;
344 keypad->dev->open = ht16k33_keypad_start;
345 keypad->dev->close = ht16k33_keypad_stop;
346
347 if (!of_get_property(node, "linux,no-autorepeat", NULL))
348 __set_bit(EV_REP, keypad->dev->evbit);
349
350 err = of_property_read_u32(node, "debounce-delay-ms",
351 &keypad->debounce_ms);
352 if (err) {
353 dev_err(&client->dev, "key debounce delay not specified\n");
354 return err;
355 }
356
357 err = matrix_keypad_parse_of_params(&client->dev, &rows, &cols);
358 if (err)
359 return err;
360 if (rows > HT16K33_MATRIX_KEYPAD_MAX_ROWS ||
361 cols > HT16K33_MATRIX_KEYPAD_MAX_COLS) {
362 dev_err(&client->dev, "%u rows or %u cols out of range in DT\n",
363 rows, cols);
364 return -ERANGE;
365 }
366
367 keypad->rows = rows;
368 keypad->cols = cols;
369 keypad->row_shift = get_count_order(cols);
370
371 err = matrix_keypad_build_keymap(NULL, NULL, rows, cols, NULL,
372 keypad->dev);
373 if (err) {
374 dev_err(&client->dev, "failed to build keymap\n");
375 return err;
376 }
377
378 err = devm_request_threaded_irq(&client->dev, client->irq,
379 NULL, ht16k33_keypad_irq_thread,
380 IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
381 DRIVER_NAME, keypad);
382 if (err) {
383 dev_err(&client->dev, "irq request failed %d, error %d\n",
384 client->irq, err);
385 return err;
386 }
387
388 ht16k33_keypad_stop(keypad->dev);
389
390 err = input_register_device(keypad->dev);
391 if (err)
392 return err;
393
394 return 0;
395}
396
397static int ht16k33_probe(struct i2c_client *client,
398 const struct i2c_device_id *id)
399{
400 int err;
401 uint32_t dft_brightness;
402 struct backlight_device *bl;
403 struct backlight_properties bl_props;
404 struct ht16k33_priv *priv;
405 struct ht16k33_fbdev *fbdev;
406 struct device_node *node = client->dev.of_node;
407
408 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
409 dev_err(&client->dev, "i2c_check_functionality error\n");
410 return -EIO;
411 }
412
413 if (client->irq <= 0) {
414 dev_err(&client->dev, "No IRQ specified\n");
415 return -EINVAL;
416 }
417
418 priv = devm_kzalloc(&client->dev, sizeof(*priv), GFP_KERNEL);
419 if (!priv)
420 return -ENOMEM;
421
422 priv->client = client;
423 i2c_set_clientdata(client, priv);
424 fbdev = &priv->fbdev;
425
426 err = ht16k33_initialize(priv);
427 if (err)
428 return err;
429
430 /* Framebuffer (2 bytes per column) */
431 BUILD_BUG_ON(PAGE_SIZE < HT16K33_FB_SIZE);
432 fbdev->buffer = (unsigned char *) get_zeroed_page(GFP_KERNEL);
433 if (!fbdev->buffer)
434 return -ENOMEM;
435
436 fbdev->cache = devm_kmalloc(&client->dev, HT16K33_FB_SIZE, GFP_KERNEL);
437 if (!fbdev->cache) {
438 err = -ENOMEM;
439 goto err_fbdev_buffer;
440 }
441
442 fbdev->info = framebuffer_alloc(0, &client->dev);
443 if (!fbdev->info) {
444 err = -ENOMEM;
445 goto err_fbdev_buffer;
446 }
447
448 err = of_property_read_u32(node, "refresh-rate-hz",
449 &fbdev->refresh_rate);
450 if (err) {
451 dev_err(&client->dev, "refresh rate not specified\n");
452 goto err_fbdev_info;
453 }
454 fb_bl_default_curve(fbdev->info, 0, MIN_BRIGHTNESS, MAX_BRIGHTNESS);
455
456 INIT_DELAYED_WORK(&fbdev->work, ht16k33_fb_update);
457 fbdev->info->fbops = &ht16k33_fb_ops;
458 fbdev->info->screen_base = (char __iomem *) fbdev->buffer;
459 fbdev->info->screen_size = HT16K33_FB_SIZE;
460 fbdev->info->fix = ht16k33_fb_fix;
461 fbdev->info->var = ht16k33_fb_var;
462 fbdev->info->pseudo_palette = NULL;
463 fbdev->info->flags = FBINFO_FLAG_DEFAULT;
464 fbdev->info->par = priv;
465
466 err = register_framebuffer(fbdev->info);
467 if (err)
468 goto err_fbdev_info;
469
470 err = ht16k33_keypad_probe(client, &priv->keypad);
471 if (err)
472 goto err_fbdev_unregister;
473
474 /* Backlight */
475 memset(&bl_props, 0, sizeof(struct backlight_properties));
476 bl_props.type = BACKLIGHT_RAW;
477 bl_props.max_brightness = MAX_BRIGHTNESS;
478
479 bl = devm_backlight_device_register(&client->dev, DRIVER_NAME"-bl",
480 &client->dev, priv,
481 &ht16k33_bl_ops, &bl_props);
482 if (IS_ERR(bl)) {
483 dev_err(&client->dev, "failed to register backlight\n");
484 err = PTR_ERR(bl);
485 goto err_fbdev_unregister;
486 }
487
488 err = of_property_read_u32(node, "default-brightness-level",
489 &dft_brightness);
490 if (err) {
491 dft_brightness = MAX_BRIGHTNESS;
492 } else if (dft_brightness > MAX_BRIGHTNESS) {
493 dev_warn(&client->dev,
494 "invalid default brightness level: %u, using %u\n",
495 dft_brightness, MAX_BRIGHTNESS);
496 dft_brightness = MAX_BRIGHTNESS;
497 }
498
499 bl->props.brightness = dft_brightness;
500 ht16k33_bl_update_status(bl);
501
502 ht16k33_fb_queue(priv);
503 return 0;
504
505err_fbdev_unregister:
506 unregister_framebuffer(fbdev->info);
507err_fbdev_info:
508 framebuffer_release(fbdev->info);
509err_fbdev_buffer:
510 free_page((unsigned long) fbdev->buffer);
511
512 return err;
513}
514
515static int ht16k33_remove(struct i2c_client *client)
516{
517 struct ht16k33_priv *priv = i2c_get_clientdata(client);
518 struct ht16k33_fbdev *fbdev = &priv->fbdev;
519
520 cancel_delayed_work(&fbdev->work);
521 unregister_framebuffer(fbdev->info);
522 framebuffer_release(fbdev->info);
523 free_page((unsigned long) fbdev->buffer);
524
525 return 0;
526}
527
528static const struct i2c_device_id ht16k33_i2c_match[] = {
529 { "ht16k33", 0 },
530 { }
531};
532MODULE_DEVICE_TABLE(i2c, ht16k33_i2c_match);
533
534static const struct of_device_id ht16k33_of_match[] = {
535 { .compatible = "holtek,ht16k33", },
536 { }
537};
538MODULE_DEVICE_TABLE(of, ht16k33_of_match);
539
540static struct i2c_driver ht16k33_driver = {
541 .probe = ht16k33_probe,
542 .remove = ht16k33_remove,
543 .driver = {
544 .name = DRIVER_NAME,
545 .of_match_table = of_match_ptr(ht16k33_of_match),
546 },
547 .id_table = ht16k33_i2c_match,
548};
549module_i2c_driver(ht16k33_driver);
550
551MODULE_DESCRIPTION("Holtek HT16K33 driver");
552MODULE_LICENSE("GPL");
553MODULE_AUTHOR("Robin van der Gracht <robin@protonic.nl>");