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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
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
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
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
149 while (pos < HT16K33_FB_SIZE && first < 0) {
150 if (*(p1++) - *(p2++))
151 first = pos;
152 pos++;
153 }
154
155
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
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
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
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
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
251
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
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
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>");
554
