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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 u8 data[HT16K33_MATRIX_KEYPAD_MAX_COLS * 2];
258 unsigned long bits_changed;
259 int row, col, code;
260 bool pressed = false;
261
262 if (i2c_smbus_read_i2c_block_data(keypad->client, 0x40, 6, data) != 6) {
263 dev_err(&keypad->client->dev, "Failed to read key data\n");
264 return false;
265 }
266
267 for (col = 0; col < keypad->cols; col++) {
268 new_state[col] = (data[col * 2 + 1] << 8) | data[col * 2];
269 if (new_state[col])
270 pressed = true;
271 bits_changed = keypad->last_key_state[col] ^ new_state[col];
272
273 for_each_set_bit(row, &bits_changed, BITS_PER_LONG) {
274 code = MATRIX_SCAN_CODE(row, col, keypad->row_shift);
275 input_event(keypad->dev, EV_MSC, MSC_SCAN, code);
276 input_report_key(keypad->dev, keycodes[code],
277 new_state[col] & BIT(row));
278 }
279 }
280 input_sync(keypad->dev);
281 memcpy(keypad->last_key_state, new_state, sizeof(new_state));
282
283 return pressed;
284}
285
286static irqreturn_t ht16k33_keypad_irq_thread(int irq, void *dev)
287{
288 struct ht16k33_keypad *keypad = dev;
289
290 do {
291 wait_event_timeout(keypad->wait, keypad->stopped,
292 msecs_to_jiffies(keypad->debounce_ms));
293 if (keypad->stopped)
294 break;
295 } while (ht16k33_keypad_scan(keypad));
296
297 return IRQ_HANDLED;
298}
299
300static int ht16k33_keypad_start(struct input_dev *dev)
301{
302 struct ht16k33_keypad *keypad = input_get_drvdata(dev);
303
304 keypad->stopped = false;
305 mb();
306 enable_irq(keypad->client->irq);
307
308 return 0;
309}
310
311static void ht16k33_keypad_stop(struct input_dev *dev)
312{
313 struct ht16k33_keypad *keypad = input_get_drvdata(dev);
314
315 keypad->stopped = true;
316 mb();
317 wake_up(&keypad->wait);
318 disable_irq(keypad->client->irq);
319}
320
321static int ht16k33_keypad_probe(struct i2c_client *client,
322 struct ht16k33_keypad *keypad)
323{
324 struct device_node *node = client->dev.of_node;
325 u32 rows = HT16K33_MATRIX_KEYPAD_MAX_ROWS;
326 u32 cols = HT16K33_MATRIX_KEYPAD_MAX_COLS;
327 int err;
328
329 keypad->client = client;
330 init_waitqueue_head(&keypad->wait);
331
332 keypad->dev = devm_input_allocate_device(&client->dev);
333 if (!keypad->dev)
334 return -ENOMEM;
335
336 input_set_drvdata(keypad->dev, keypad);
337
338 keypad->dev->name = DRIVER_NAME"-keypad";
339 keypad->dev->id.bustype = BUS_I2C;
340 keypad->dev->open = ht16k33_keypad_start;
341 keypad->dev->close = ht16k33_keypad_stop;
342
343 if (!of_get_property(node, "linux,no-autorepeat", NULL))
344 __set_bit(EV_REP, keypad->dev->evbit);
345
346 err = of_property_read_u32(node, "debounce-delay-ms",
347 &keypad->debounce_ms);
348 if (err) {
349 dev_err(&client->dev, "key debounce delay not specified\n");
350 return err;
351 }
352
353 err = matrix_keypad_parse_of_params(&client->dev, &rows, &cols);
354 if (err)
355 return err;
356
357 keypad->rows = rows;
358 keypad->cols = cols;
359 keypad->row_shift = get_count_order(cols);
360
361 err = matrix_keypad_build_keymap(NULL, NULL, rows, cols, NULL,
362 keypad->dev);
363 if (err) {
364 dev_err(&client->dev, "failed to build keymap\n");
365 return err;
366 }
367
368 err = devm_request_threaded_irq(&client->dev, client->irq,
369 NULL, ht16k33_keypad_irq_thread,
370 IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
371 DRIVER_NAME, keypad);
372 if (err) {
373 dev_err(&client->dev, "irq request failed %d, error %d\n",
374 client->irq, err);
375 return err;
376 }
377
378 ht16k33_keypad_stop(keypad->dev);
379
380 err = input_register_device(keypad->dev);
381 if (err)
382 return err;
383
384 return 0;
385}
386
387static int ht16k33_probe(struct i2c_client *client,
388 const struct i2c_device_id *id)
389{
390 int err;
391 uint32_t dft_brightness;
392 struct backlight_device *bl;
393 struct backlight_properties bl_props;
394 struct ht16k33_priv *priv;
395 struct ht16k33_fbdev *fbdev;
396 struct device_node *node = client->dev.of_node;
397
398 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
399 dev_err(&client->dev, "i2c_check_functionality error\n");
400 return -EIO;
401 }
402
403 if (client->irq <= 0) {
404 dev_err(&client->dev, "No IRQ specified\n");
405 return -EINVAL;
406 }
407
408 priv = devm_kzalloc(&client->dev, sizeof(*priv), GFP_KERNEL);
409 if (!priv)
410 return -ENOMEM;
411
412 priv->client = client;
413 i2c_set_clientdata(client, priv);
414 fbdev = &priv->fbdev;
415
416 err = ht16k33_initialize(priv);
417 if (err)
418 return err;
419
420
421 BUILD_BUG_ON(PAGE_SIZE < HT16K33_FB_SIZE);
422 fbdev->buffer = (unsigned char *) get_zeroed_page(GFP_KERNEL);
423 if (!fbdev->buffer)
424 return -ENOMEM;
425
426 fbdev->cache = devm_kmalloc(&client->dev, HT16K33_FB_SIZE, GFP_KERNEL);
427 if (!fbdev->cache) {
428 err = -ENOMEM;
429 goto err_fbdev_buffer;
430 }
431
432 fbdev->info = framebuffer_alloc(0, &client->dev);
433 if (!fbdev->info) {
434 err = -ENOMEM;
435 goto err_fbdev_buffer;
436 }
437
438 err = of_property_read_u32(node, "refresh-rate-hz",
439 &fbdev->refresh_rate);
440 if (err) {
441 dev_err(&client->dev, "refresh rate not specified\n");
442 goto err_fbdev_info;
443 }
444 fb_bl_default_curve(fbdev->info, 0, MIN_BRIGHTNESS, MAX_BRIGHTNESS);
445
446 INIT_DELAYED_WORK(&fbdev->work, ht16k33_fb_update);
447 fbdev->info->fbops = &ht16k33_fb_ops;
448 fbdev->info->screen_base = (char __iomem *) fbdev->buffer;
449 fbdev->info->screen_size = HT16K33_FB_SIZE;
450 fbdev->info->fix = ht16k33_fb_fix;
451 fbdev->info->var = ht16k33_fb_var;
452 fbdev->info->pseudo_palette = NULL;
453 fbdev->info->flags = FBINFO_FLAG_DEFAULT;
454 fbdev->info->par = priv;
455
456 err = register_framebuffer(fbdev->info);
457 if (err)
458 goto err_fbdev_info;
459
460 err = ht16k33_keypad_probe(client, &priv->keypad);
461 if (err)
462 goto err_fbdev_unregister;
463
464
465 memset(&bl_props, 0, sizeof(struct backlight_properties));
466 bl_props.type = BACKLIGHT_RAW;
467 bl_props.max_brightness = MAX_BRIGHTNESS;
468
469 bl = devm_backlight_device_register(&client->dev, DRIVER_NAME"-bl",
470 &client->dev, priv,
471 &ht16k33_bl_ops, &bl_props);
472 if (IS_ERR(bl)) {
473 dev_err(&client->dev, "failed to register backlight\n");
474 err = PTR_ERR(bl);
475 goto err_fbdev_unregister;
476 }
477
478 err = of_property_read_u32(node, "default-brightness-level",
479 &dft_brightness);
480 if (err) {
481 dft_brightness = MAX_BRIGHTNESS;
482 } else if (dft_brightness > MAX_BRIGHTNESS) {
483 dev_warn(&client->dev,
484 "invalid default brightness level: %u, using %u\n",
485 dft_brightness, MAX_BRIGHTNESS);
486 dft_brightness = MAX_BRIGHTNESS;
487 }
488
489 bl->props.brightness = dft_brightness;
490 ht16k33_bl_update_status(bl);
491
492 ht16k33_fb_queue(priv);
493 return 0;
494
495err_fbdev_unregister:
496 unregister_framebuffer(fbdev->info);
497err_fbdev_info:
498 framebuffer_release(fbdev->info);
499err_fbdev_buffer:
500 free_page((unsigned long) fbdev->buffer);
501
502 return err;
503}
504
505static int ht16k33_remove(struct i2c_client *client)
506{
507 struct ht16k33_priv *priv = i2c_get_clientdata(client);
508 struct ht16k33_fbdev *fbdev = &priv->fbdev;
509
510 cancel_delayed_work(&fbdev->work);
511 unregister_framebuffer(fbdev->info);
512 framebuffer_release(fbdev->info);
513 free_page((unsigned long) fbdev->buffer);
514
515 return 0;
516}
517
518static const struct i2c_device_id ht16k33_i2c_match[] = {
519 { "ht16k33", 0 },
520 { }
521};
522MODULE_DEVICE_TABLE(i2c, ht16k33_i2c_match);
523
524static const struct of_device_id ht16k33_of_match[] = {
525 { .compatible = "holtek,ht16k33", },
526 { }
527};
528MODULE_DEVICE_TABLE(of, ht16k33_of_match);
529
530static struct i2c_driver ht16k33_driver = {
531 .probe = ht16k33_probe,
532 .remove = ht16k33_remove,
533 .driver = {
534 .name = DRIVER_NAME,
535 .of_match_table = of_match_ptr(ht16k33_of_match),
536 },
537 .id_table = ht16k33_i2c_match,
538};
539module_i2c_driver(ht16k33_driver);
540
541MODULE_DESCRIPTION("Holtek HT16K33 driver");
542MODULE_LICENSE("GPL");
543MODULE_AUTHOR("Robin van der Gracht <robin@protonic.nl>");
544
