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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 */
9
10#include <linux/kernel.h>
11#include <linux/module.h>
12#include <linux/interrupt.h>
13#include <linux/i2c.h>
14#include <linux/of.h>
15#include <linux/fb.h>
16#include <linux/slab.h>
17#include <linux/backlight.h>
18#include <linux/input.h>
19#include <linux/input/matrix_keypad.h>
20#include <linux/workqueue.h>
21#include <linux/mm.h>
22
23/* Registers */
24#define REG_SYSTEM_SETUP 0x20
25#define REG_SYSTEM_SETUP_OSC_ON BIT(0)
26
27#define REG_DISPLAY_SETUP 0x80
28#define REG_DISPLAY_SETUP_ON BIT(0)
29
30#define REG_ROWINT_SET 0xA0
31#define REG_ROWINT_SET_INT_EN BIT(0)
32#define REG_ROWINT_SET_INT_ACT_HIGH BIT(1)
33
34#define REG_BRIGHTNESS 0xE0
35
36/* Defines */
37#define DRIVER_NAME "ht16k33"
38
39#define MIN_BRIGHTNESS 0x1
40#define MAX_BRIGHTNESS 0x10
41
42#define HT16K33_MATRIX_LED_MAX_COLS 8
43#define HT16K33_MATRIX_LED_MAX_ROWS 16
44#define HT16K33_MATRIX_KEYPAD_MAX_COLS 3
45#define HT16K33_MATRIX_KEYPAD_MAX_ROWS 12
46
47#define BYTES_PER_ROW (HT16K33_MATRIX_LED_MAX_ROWS / 8)
48#define HT16K33_FB_SIZE (HT16K33_MATRIX_LED_MAX_COLS * BYTES_PER_ROW)
49
50struct ht16k33_keypad {
51 struct i2c_client *client;
52 struct input_dev *dev;
53 uint32_t cols;
54 uint32_t rows;
55 uint32_t row_shift;
56 uint32_t debounce_ms;
57 uint16_t last_key_state[HT16K33_MATRIX_KEYPAD_MAX_COLS];
58
59 wait_queue_head_t wait;
60 bool stopped;
61};
62
63struct ht16k33_fbdev {
64 struct fb_info *info;
65 uint32_t refresh_rate;
66 uint8_t *buffer;
67 uint8_t *cache;
68 struct delayed_work work;
69};
70
71struct ht16k33_priv {
72 struct i2c_client *client;
73 struct ht16k33_keypad keypad;
74 struct ht16k33_fbdev fbdev;
75};
76
77static const struct fb_fix_screeninfo ht16k33_fb_fix = {
78 .id = DRIVER_NAME,
79 .type = FB_TYPE_PACKED_PIXELS,
80 .visual = FB_VISUAL_MONO10,
81 .xpanstep = 0,
82 .ypanstep = 0,
83 .ywrapstep = 0,
84 .line_length = HT16K33_MATRIX_LED_MAX_ROWS,
85 .accel = FB_ACCEL_NONE,
86};
87
88static const struct fb_var_screeninfo ht16k33_fb_var = {
89 .xres = HT16K33_MATRIX_LED_MAX_ROWS,
90 .yres = HT16K33_MATRIX_LED_MAX_COLS,
91 .xres_virtual = HT16K33_MATRIX_LED_MAX_ROWS,
92 .yres_virtual = HT16K33_MATRIX_LED_MAX_COLS,
93 .bits_per_pixel = 1,
94 .red = { 0, 1, 0 },
95 .green = { 0, 1, 0 },
96 .blue = { 0, 1, 0 },
97 .left_margin = 0,
98 .right_margin = 0,
99 .upper_margin = 0,
100 .lower_margin = 0,
101 .vmode = FB_VMODE_NONINTERLACED,
102};
103
104static int ht16k33_display_on(struct ht16k33_priv *priv)
105{
106 uint8_t data = REG_DISPLAY_SETUP | REG_DISPLAY_SETUP_ON;
107
108 return i2c_smbus_write_byte(priv->client, data);
109}
110
111static int ht16k33_display_off(struct ht16k33_priv *priv)
112{
113 return i2c_smbus_write_byte(priv->client, REG_DISPLAY_SETUP);
114}
115
116static void ht16k33_fb_queue(struct ht16k33_priv *priv)
117{
118 struct ht16k33_fbdev *fbdev = &priv->fbdev;
119
120 schedule_delayed_work(&fbdev->work,
121 msecs_to_jiffies(HZ / fbdev->refresh_rate));
122}
123
124/*
125 * This gets the fb data from cache and copies it to ht16k33 display RAM
126 */
127static void ht16k33_fb_update(struct work_struct *work)
128{
129 struct ht16k33_fbdev *fbdev =
130 container_of(work, struct ht16k33_fbdev, work.work);
131 struct ht16k33_priv *priv =
132 container_of(fbdev, struct ht16k33_priv, fbdev);
133
134 uint8_t *p1, *p2;
135 int len, pos = 0, first = -1;
136
137 p1 = fbdev->cache;
138 p2 = fbdev->buffer;
139
140 /* Search for the first byte with changes */
141 while (pos < HT16K33_FB_SIZE && first < 0) {
142 if (*(p1++) - *(p2++))
143 first = pos;
144 pos++;
145 }
146
147 /* No changes found */
148 if (first < 0)
149 goto requeue;
150
151 len = HT16K33_FB_SIZE - first;
152 p1 = fbdev->cache + HT16K33_FB_SIZE - 1;
153 p2 = fbdev->buffer + HT16K33_FB_SIZE - 1;
154
155 /* Determine i2c transfer length */
156 while (len > 1) {
157 if (*(p1--) - *(p2--))
158 break;
159 len--;
160 }
161
162 p1 = fbdev->cache + first;
163 p2 = fbdev->buffer + first;
164 if (!i2c_smbus_write_i2c_block_data(priv->client, first, len, p2))
165 memcpy(p1, p2, len);
166requeue:
167 ht16k33_fb_queue(priv);
168}
169
170static int ht16k33_initialize(struct ht16k33_priv *priv)
171{
172 uint8_t byte;
173 int err;
174 uint8_t data[HT16K33_MATRIX_LED_MAX_COLS * 2];
175
176 /* Clear RAM (8 * 16 bits) */
177 memset(data, 0, sizeof(data));
178 err = i2c_smbus_write_block_data(priv->client, 0, sizeof(data), data);
179 if (err)
180 return err;
181
182 /* Turn on internal oscillator */
183 byte = REG_SYSTEM_SETUP_OSC_ON | REG_SYSTEM_SETUP;
184 err = i2c_smbus_write_byte(priv->client, byte);
185 if (err)
186 return err;
187
188 /* Configure INT pin */
189 byte = REG_ROWINT_SET | REG_ROWINT_SET_INT_ACT_HIGH;
190 if (priv->client->irq > 0)
191 byte |= REG_ROWINT_SET_INT_EN;
192 return i2c_smbus_write_byte(priv->client, byte);
193}
194
195static int ht16k33_bl_update_status(struct backlight_device *bl)
196{
197 int brightness = bl->props.brightness;
198 struct ht16k33_priv *priv = bl_get_data(bl);
199
200 if (bl->props.power != FB_BLANK_UNBLANK ||
201 bl->props.fb_blank != FB_BLANK_UNBLANK ||
202 bl->props.state & BL_CORE_FBBLANK || brightness == 0) {
203 return ht16k33_display_off(priv);
204 }
205
206 ht16k33_display_on(priv);
207 return i2c_smbus_write_byte(priv->client,
208 REG_BRIGHTNESS | (brightness - 1));
209}
210
211static int ht16k33_bl_check_fb(struct backlight_device *bl, struct fb_info *fi)
212{
213 struct ht16k33_priv *priv = bl_get_data(bl);
214
215 return (fi == NULL) || (fi->par == priv);
216}
217
218static const struct backlight_ops ht16k33_bl_ops = {
219 .update_status = ht16k33_bl_update_status,
220 .check_fb = ht16k33_bl_check_fb,
221};
222
223static int ht16k33_mmap(struct fb_info *info, struct vm_area_struct *vma)
224{
225 struct ht16k33_priv *priv = info->par;
226 struct page *pages = virt_to_page(priv->fbdev.buffer);
227
228 return vm_map_pages_zero(vma, &pages, 1);
229}
230
231static const struct fb_ops ht16k33_fb_ops = {
232 .owner = THIS_MODULE,
233 .fb_read = fb_sys_read,
234 .fb_write = fb_sys_write,
235 .fb_fillrect = sys_fillrect,
236 .fb_copyarea = sys_copyarea,
237 .fb_imageblit = sys_imageblit,
238 .fb_mmap = ht16k33_mmap,
239};
240
241/*
242 * This gets the keys from keypad and reports it to input subsystem.
243 * Returns true if a key is pressed.
244 */
245static bool ht16k33_keypad_scan(struct ht16k33_keypad *keypad)
246{
247 const unsigned short *keycodes = keypad->dev->keycode;
248 u16 new_state[HT16K33_MATRIX_KEYPAD_MAX_COLS];
249 __le16 data[HT16K33_MATRIX_KEYPAD_MAX_COLS];
250 unsigned long bits_changed;
251 int row, col, code;
252 int rc;
253 bool pressed = false;
254
255 rc = i2c_smbus_read_i2c_block_data(keypad->client, 0x40,
256 sizeof(data), (u8 *)data);
257 if (rc != sizeof(data)) {
258 dev_err(&keypad->client->dev,
259 "Failed to read key data, rc=%d\n", rc);
260 return false;
261 }
262
263 for (col = 0; col < keypad->cols; col++) {
264 new_state[col] = le16_to_cpu(data[col]);
265 if (new_state[col])
266 pressed = true;
267 bits_changed = keypad->last_key_state[col] ^ new_state[col];
268
269 for_each_set_bit(row, &bits_changed, BITS_PER_LONG) {
270 code = MATRIX_SCAN_CODE(row, col, keypad->row_shift);
271 input_event(keypad->dev, EV_MSC, MSC_SCAN, code);
272 input_report_key(keypad->dev, keycodes[code],
273 new_state[col] & BIT(row));
274 }
275 }
276 input_sync(keypad->dev);
277 memcpy(keypad->last_key_state, new_state, sizeof(u16) * keypad->cols);
278
279 return pressed;
280}
281
282static irqreturn_t ht16k33_keypad_irq_thread(int irq, void *dev)
283{
284 struct ht16k33_keypad *keypad = dev;
285
286 do {
287 wait_event_timeout(keypad->wait, keypad->stopped,
288 msecs_to_jiffies(keypad->debounce_ms));
289 if (keypad->stopped)
290 break;
291 } while (ht16k33_keypad_scan(keypad));
292
293 return IRQ_HANDLED;
294}
295
296static int ht16k33_keypad_start(struct input_dev *dev)
297{
298 struct ht16k33_keypad *keypad = input_get_drvdata(dev);
299
300 keypad->stopped = false;
301 mb();
302 enable_irq(keypad->client->irq);
303
304 return 0;
305}
306
307static void ht16k33_keypad_stop(struct input_dev *dev)
308{
309 struct ht16k33_keypad *keypad = input_get_drvdata(dev);
310
311 keypad->stopped = true;
312 mb();
313 wake_up(&keypad->wait);
314 disable_irq(keypad->client->irq);
315}
316
317static int ht16k33_keypad_probe(struct i2c_client *client,
318 struct ht16k33_keypad *keypad)
319{
320 struct device_node *node = client->dev.of_node;
321 u32 rows = HT16K33_MATRIX_KEYPAD_MAX_ROWS;
322 u32 cols = HT16K33_MATRIX_KEYPAD_MAX_COLS;
323 int err;
324
325 keypad->client = client;
326 init_waitqueue_head(&keypad->wait);
327
328 keypad->dev = devm_input_allocate_device(&client->dev);
329 if (!keypad->dev)
330 return -ENOMEM;
331
332 input_set_drvdata(keypad->dev, keypad);
333
334 keypad->dev->name = DRIVER_NAME"-keypad";
335 keypad->dev->id.bustype = BUS_I2C;
336 keypad->dev->open = ht16k33_keypad_start;
337 keypad->dev->close = ht16k33_keypad_stop;
338
339 if (!of_get_property(node, "linux,no-autorepeat", NULL))
340 __set_bit(EV_REP, keypad->dev->evbit);
341
342 err = of_property_read_u32(node, "debounce-delay-ms",
343 &keypad->debounce_ms);
344 if (err) {
345 dev_err(&client->dev, "key debounce delay not specified\n");
346 return err;
347 }
348
349 err = matrix_keypad_parse_of_params(&client->dev, &rows, &cols);
350 if (err)
351 return err;
352 if (rows > HT16K33_MATRIX_KEYPAD_MAX_ROWS ||
353 cols > HT16K33_MATRIX_KEYPAD_MAX_COLS) {
354 dev_err(&client->dev, "%u rows or %u cols out of range in DT\n",
355 rows, cols);
356 return -ERANGE;
357 }
358
359 keypad->rows = rows;
360 keypad->cols = cols;
361 keypad->row_shift = get_count_order(cols);
362
363 err = matrix_keypad_build_keymap(NULL, NULL, rows, cols, NULL,
364 keypad->dev);
365 if (err) {
366 dev_err(&client->dev, "failed to build keymap\n");
367 return err;
368 }
369
370 err = devm_request_threaded_irq(&client->dev, client->irq,
371 NULL, ht16k33_keypad_irq_thread,
372 IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
373 DRIVER_NAME, keypad);
374 if (err) {
375 dev_err(&client->dev, "irq request failed %d, error %d\n",
376 client->irq, err);
377 return err;
378 }
379
380 ht16k33_keypad_stop(keypad->dev);
381
382 err = input_register_device(keypad->dev);
383 if (err)
384 return err;
385
386 return 0;
387}
388
389static int ht16k33_probe(struct i2c_client *client,
390 const struct i2c_device_id *id)
391{
392 int err;
393 uint32_t dft_brightness;
394 struct backlight_device *bl;
395 struct backlight_properties bl_props;
396 struct ht16k33_priv *priv;
397 struct ht16k33_fbdev *fbdev;
398 struct device_node *node = client->dev.of_node;
399
400 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
401 dev_err(&client->dev, "i2c_check_functionality error\n");
402 return -EIO;
403 }
404
405 if (client->irq <= 0) {
406 dev_err(&client->dev, "No IRQ specified\n");
407 return -EINVAL;
408 }
409
410 priv = devm_kzalloc(&client->dev, sizeof(*priv), GFP_KERNEL);
411 if (!priv)
412 return -ENOMEM;
413
414 priv->client = client;
415 i2c_set_clientdata(client, priv);
416 fbdev = &priv->fbdev;
417
418 err = ht16k33_initialize(priv);
419 if (err)
420 return err;
421
422 /* Framebuffer (2 bytes per column) */
423 BUILD_BUG_ON(PAGE_SIZE < HT16K33_FB_SIZE);
424 fbdev->buffer = (unsigned char *) get_zeroed_page(GFP_KERNEL);
425 if (!fbdev->buffer)
426 return -ENOMEM;
427
428 fbdev->cache = devm_kmalloc(&client->dev, HT16K33_FB_SIZE, GFP_KERNEL);
429 if (!fbdev->cache) {
430 err = -ENOMEM;
431 goto err_fbdev_buffer;
432 }
433
434 fbdev->info = framebuffer_alloc(0, &client->dev);
435 if (!fbdev->info) {
436 err = -ENOMEM;
437 goto err_fbdev_buffer;
438 }
439
440 err = of_property_read_u32(node, "refresh-rate-hz",
441 &fbdev->refresh_rate);
442 if (err) {
443 dev_err(&client->dev, "refresh rate not specified\n");
444 goto err_fbdev_info;
445 }
446 fb_bl_default_curve(fbdev->info, 0, MIN_BRIGHTNESS, MAX_BRIGHTNESS);
447
448 INIT_DELAYED_WORK(&fbdev->work, ht16k33_fb_update);
449 fbdev->info->fbops = &ht16k33_fb_ops;
450 fbdev->info->screen_base = (char __iomem *) fbdev->buffer;
451 fbdev->info->screen_size = HT16K33_FB_SIZE;
452 fbdev->info->fix = ht16k33_fb_fix;
453 fbdev->info->var = ht16k33_fb_var;
454 fbdev->info->pseudo_palette = NULL;
455 fbdev->info->flags = FBINFO_FLAG_DEFAULT;
456 fbdev->info->par = priv;
457
458 err = register_framebuffer(fbdev->info);
459 if (err)
460 goto err_fbdev_info;
461
462 err = ht16k33_keypad_probe(client, &priv->keypad);
463 if (err)
464 goto err_fbdev_unregister;
465
466 /* Backlight */
467 memset(&bl_props, 0, sizeof(struct backlight_properties));
468 bl_props.type = BACKLIGHT_RAW;
469 bl_props.max_brightness = MAX_BRIGHTNESS;
470
471 bl = devm_backlight_device_register(&client->dev, DRIVER_NAME"-bl",
472 &client->dev, priv,
473 &ht16k33_bl_ops, &bl_props);
474 if (IS_ERR(bl)) {
475 dev_err(&client->dev, "failed to register backlight\n");
476 err = PTR_ERR(bl);
477 goto err_fbdev_unregister;
478 }
479
480 err = of_property_read_u32(node, "default-brightness-level",
481 &dft_brightness);
482 if (err) {
483 dft_brightness = MAX_BRIGHTNESS;
484 } else if (dft_brightness > MAX_BRIGHTNESS) {
485 dev_warn(&client->dev,
486 "invalid default brightness level: %u, using %u\n",
487 dft_brightness, MAX_BRIGHTNESS);
488 dft_brightness = MAX_BRIGHTNESS;
489 }
490
491 bl->props.brightness = dft_brightness;
492 ht16k33_bl_update_status(bl);
493
494 ht16k33_fb_queue(priv);
495 return 0;
496
497err_fbdev_unregister:
498 unregister_framebuffer(fbdev->info);
499err_fbdev_info:
500 framebuffer_release(fbdev->info);
501err_fbdev_buffer:
502 free_page((unsigned long) fbdev->buffer);
503
504 return err;
505}
506
507static int ht16k33_remove(struct i2c_client *client)
508{
509 struct ht16k33_priv *priv = i2c_get_clientdata(client);
510 struct ht16k33_fbdev *fbdev = &priv->fbdev;
511
512 cancel_delayed_work_sync(&fbdev->work);
513 unregister_framebuffer(fbdev->info);
514 framebuffer_release(fbdev->info);
515 free_page((unsigned long) fbdev->buffer);
516
517 return 0;
518}
519
520static const struct i2c_device_id ht16k33_i2c_match[] = {
521 { "ht16k33", 0 },
522 { }
523};
524MODULE_DEVICE_TABLE(i2c, ht16k33_i2c_match);
525
526static const struct of_device_id ht16k33_of_match[] = {
527 { .compatible = "holtek,ht16k33", },
528 { }
529};
530MODULE_DEVICE_TABLE(of, ht16k33_of_match);
531
532static struct i2c_driver ht16k33_driver = {
533 .probe = ht16k33_probe,
534 .remove = ht16k33_remove,
535 .driver = {
536 .name = DRIVER_NAME,
537 .of_match_table = of_match_ptr(ht16k33_of_match),
538 },
539 .id_table = ht16k33_i2c_match,
540};
541module_i2c_driver(ht16k33_driver);
542
543MODULE_DESCRIPTION("Holtek HT16K33 driver");
544MODULE_LICENSE("GPL");
545MODULE_AUTHOR("Robin van der Gracht <robin@protonic.nl>");
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 input_dev *dev;
60 spinlock_t lock;
61 struct delayed_work work;
62 uint32_t cols;
63 uint32_t rows;
64 uint32_t row_shift;
65 uint32_t debounce_ms;
66 uint16_t last_key_state[HT16K33_MATRIX_KEYPAD_MAX_COLS];
67};
68
69struct ht16k33_fbdev {
70 struct fb_info *info;
71 uint32_t refresh_rate;
72 uint8_t *buffer;
73 uint8_t *cache;
74 struct delayed_work work;
75};
76
77struct ht16k33_priv {
78 struct i2c_client *client;
79 struct ht16k33_keypad keypad;
80 struct ht16k33_fbdev fbdev;
81 struct workqueue_struct *workqueue;
82};
83
84static struct fb_fix_screeninfo ht16k33_fb_fix = {
85 .id = DRIVER_NAME,
86 .type = FB_TYPE_PACKED_PIXELS,
87 .visual = FB_VISUAL_MONO10,
88 .xpanstep = 0,
89 .ypanstep = 0,
90 .ywrapstep = 0,
91 .line_length = HT16K33_MATRIX_LED_MAX_ROWS,
92 .accel = FB_ACCEL_NONE,
93};
94
95static struct fb_var_screeninfo ht16k33_fb_var = {
96 .xres = HT16K33_MATRIX_LED_MAX_ROWS,
97 .yres = HT16K33_MATRIX_LED_MAX_COLS,
98 .xres_virtual = HT16K33_MATRIX_LED_MAX_ROWS,
99 .yres_virtual = HT16K33_MATRIX_LED_MAX_COLS,
100 .bits_per_pixel = 1,
101 .red = { 0, 1, 0 },
102 .green = { 0, 1, 0 },
103 .blue = { 0, 1, 0 },
104 .left_margin = 0,
105 .right_margin = 0,
106 .upper_margin = 0,
107 .lower_margin = 0,
108 .vmode = FB_VMODE_NONINTERLACED,
109};
110
111static int ht16k33_display_on(struct ht16k33_priv *priv)
112{
113 uint8_t data = REG_DISPLAY_SETUP | REG_DISPLAY_SETUP_ON;
114
115 return i2c_smbus_write_byte(priv->client, data);
116}
117
118static int ht16k33_display_off(struct ht16k33_priv *priv)
119{
120 return i2c_smbus_write_byte(priv->client, REG_DISPLAY_SETUP);
121}
122
123static void ht16k33_fb_queue(struct ht16k33_priv *priv)
124{
125 struct ht16k33_fbdev *fbdev = &priv->fbdev;
126
127 queue_delayed_work(priv->workqueue, &fbdev->work,
128 msecs_to_jiffies(HZ / fbdev->refresh_rate));
129}
130
131static void ht16k33_keypad_queue(struct ht16k33_priv *priv)
132{
133 struct ht16k33_keypad *keypad = &priv->keypad;
134
135 queue_delayed_work(priv->workqueue, &keypad->work,
136 msecs_to_jiffies(keypad->debounce_ms));
137}
138
139/*
140 * This gets the fb data from cache and copies it to ht16k33 display RAM
141 */
142static void ht16k33_fb_update(struct work_struct *work)
143{
144 struct ht16k33_fbdev *fbdev =
145 container_of(work, struct ht16k33_fbdev, work.work);
146 struct ht16k33_priv *priv =
147 container_of(fbdev, struct ht16k33_priv, fbdev);
148
149 uint8_t *p1, *p2;
150 int len, pos = 0, first = -1;
151
152 p1 = fbdev->cache;
153 p2 = fbdev->buffer;
154
155 /* Search for the first byte with changes */
156 while (pos < HT16K33_FB_SIZE && first < 0) {
157 if (*(p1++) - *(p2++))
158 first = pos;
159 pos++;
160 }
161
162 /* No changes found */
163 if (first < 0)
164 goto requeue;
165
166 len = HT16K33_FB_SIZE - first;
167 p1 = fbdev->cache + HT16K33_FB_SIZE - 1;
168 p2 = fbdev->buffer + HT16K33_FB_SIZE - 1;
169
170 /* Determine i2c transfer length */
171 while (len > 1) {
172 if (*(p1--) - *(p2--))
173 break;
174 len--;
175 }
176
177 p1 = fbdev->cache + first;
178 p2 = fbdev->buffer + first;
179 if (!i2c_smbus_write_i2c_block_data(priv->client, first, len, p2))
180 memcpy(p1, p2, len);
181requeue:
182 ht16k33_fb_queue(priv);
183}
184
185static int ht16k33_keypad_start(struct input_dev *dev)
186{
187 struct ht16k33_priv *priv = input_get_drvdata(dev);
188 struct ht16k33_keypad *keypad = &priv->keypad;
189
190 /*
191 * Schedule an immediate key scan to capture current key state;
192 * columns will be activated and IRQs be enabled after the scan.
193 */
194 queue_delayed_work(priv->workqueue, &keypad->work, 0);
195 return 0;
196}
197
198static void ht16k33_keypad_stop(struct input_dev *dev)
199{
200 struct ht16k33_priv *priv = input_get_drvdata(dev);
201 struct ht16k33_keypad *keypad = &priv->keypad;
202
203 cancel_delayed_work(&keypad->work);
204 /*
205 * ht16k33_keypad_scan() will leave IRQs enabled;
206 * we should disable them now.
207 */
208 disable_irq_nosync(priv->client->irq);
209}
210
211static int ht16k33_initialize(struct ht16k33_priv *priv)
212{
213 uint8_t byte;
214 int err;
215 uint8_t data[HT16K33_MATRIX_LED_MAX_COLS * 2];
216
217 /* Clear RAM (8 * 16 bits) */
218 memset(data, 0, sizeof(data));
219 err = i2c_smbus_write_block_data(priv->client, 0, sizeof(data), data);
220 if (err)
221 return err;
222
223 /* Turn on internal oscillator */
224 byte = REG_SYSTEM_SETUP_OSC_ON | REG_SYSTEM_SETUP;
225 err = i2c_smbus_write_byte(priv->client, byte);
226 if (err)
227 return err;
228
229 /* Configure INT pin */
230 byte = REG_ROWINT_SET | REG_ROWINT_SET_INT_ACT_HIGH;
231 if (priv->client->irq > 0)
232 byte |= REG_ROWINT_SET_INT_EN;
233 return i2c_smbus_write_byte(priv->client, byte);
234}
235
236/*
237 * This gets the keys from keypad and reports it to input subsystem
238 */
239static void ht16k33_keypad_scan(struct work_struct *work)
240{
241 struct ht16k33_keypad *keypad =
242 container_of(work, struct ht16k33_keypad, work.work);
243 struct ht16k33_priv *priv =
244 container_of(keypad, struct ht16k33_priv, keypad);
245 const unsigned short *keycodes = keypad->dev->keycode;
246 uint16_t bits_changed, new_state[HT16K33_MATRIX_KEYPAD_MAX_COLS];
247 uint8_t data[HT16K33_MATRIX_KEYPAD_MAX_COLS * 2];
248 int row, col, code;
249 bool reschedule = false;
250
251 if (i2c_smbus_read_i2c_block_data(priv->client, 0x40, 6, data) != 6) {
252 dev_err(&priv->client->dev, "Failed to read key data\n");
253 goto end;
254 }
255
256 for (col = 0; col < keypad->cols; col++) {
257 new_state[col] = (data[col * 2 + 1] << 8) | data[col * 2];
258 if (new_state[col])
259 reschedule = true;
260 bits_changed = keypad->last_key_state[col] ^ new_state[col];
261
262 while (bits_changed) {
263 row = ffs(bits_changed) - 1;
264 code = MATRIX_SCAN_CODE(row, col, keypad->row_shift);
265 input_event(keypad->dev, EV_MSC, MSC_SCAN, code);
266 input_report_key(keypad->dev, keycodes[code],
267 new_state[col] & BIT(row));
268 bits_changed &= ~BIT(row);
269 }
270 }
271 input_sync(keypad->dev);
272 memcpy(keypad->last_key_state, new_state, sizeof(new_state));
273
274end:
275 if (reschedule)
276 ht16k33_keypad_queue(priv);
277 else
278 enable_irq(priv->client->irq);
279}
280
281static irqreturn_t ht16k33_irq_thread(int irq, void *dev)
282{
283 struct ht16k33_priv *priv = dev;
284
285 disable_irq_nosync(priv->client->irq);
286 ht16k33_keypad_queue(priv);
287
288 return IRQ_HANDLED;
289}
290
291static int ht16k33_bl_update_status(struct backlight_device *bl)
292{
293 int brightness = bl->props.brightness;
294 struct ht16k33_priv *priv = bl_get_data(bl);
295
296 if (bl->props.power != FB_BLANK_UNBLANK ||
297 bl->props.fb_blank != FB_BLANK_UNBLANK ||
298 bl->props.state & BL_CORE_FBBLANK || brightness == 0) {
299 return ht16k33_display_off(priv);
300 }
301
302 ht16k33_display_on(priv);
303 return i2c_smbus_write_byte(priv->client,
304 REG_BRIGHTNESS | (brightness - 1));
305}
306
307static int ht16k33_bl_check_fb(struct backlight_device *bl, struct fb_info *fi)
308{
309 struct ht16k33_priv *priv = bl_get_data(bl);
310
311 return (fi == NULL) || (fi->par == priv);
312}
313
314static const struct backlight_ops ht16k33_bl_ops = {
315 .update_status = ht16k33_bl_update_status,
316 .check_fb = ht16k33_bl_check_fb,
317};
318
319static int ht16k33_mmap(struct fb_info *info, struct vm_area_struct *vma)
320{
321 struct ht16k33_priv *priv = info->par;
322
323 return vm_insert_page(vma, vma->vm_start,
324 virt_to_page(priv->fbdev.buffer));
325}
326
327static struct fb_ops ht16k33_fb_ops = {
328 .owner = THIS_MODULE,
329 .fb_read = fb_sys_read,
330 .fb_write = fb_sys_write,
331 .fb_fillrect = sys_fillrect,
332 .fb_copyarea = sys_copyarea,
333 .fb_imageblit = sys_imageblit,
334 .fb_mmap = ht16k33_mmap,
335};
336
337static int ht16k33_probe(struct i2c_client *client,
338 const struct i2c_device_id *id)
339{
340 int err;
341 uint32_t rows, cols, dft_brightness;
342 struct backlight_device *bl;
343 struct backlight_properties bl_props;
344 struct ht16k33_priv *priv;
345 struct ht16k33_keypad *keypad;
346 struct ht16k33_fbdev *fbdev;
347 struct device_node *node = client->dev.of_node;
348
349 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
350 dev_err(&client->dev, "i2c_check_functionality error\n");
351 return -EIO;
352 }
353
354 if (client->irq <= 0) {
355 dev_err(&client->dev, "No IRQ specified\n");
356 return -EINVAL;
357 }
358
359 priv = devm_kzalloc(&client->dev, sizeof(*priv), GFP_KERNEL);
360 if (!priv)
361 return -ENOMEM;
362
363 priv->client = client;
364 i2c_set_clientdata(client, priv);
365 fbdev = &priv->fbdev;
366 keypad = &priv->keypad;
367
368 priv->workqueue = create_singlethread_workqueue(DRIVER_NAME "-wq");
369 if (priv->workqueue == NULL)
370 return -ENOMEM;
371
372 err = ht16k33_initialize(priv);
373 if (err)
374 goto err_destroy_wq;
375
376 /* Framebuffer (2 bytes per column) */
377 BUILD_BUG_ON(PAGE_SIZE < HT16K33_FB_SIZE);
378 fbdev->buffer = (unsigned char *) get_zeroed_page(GFP_KERNEL);
379 if (!fbdev->buffer) {
380 err = -ENOMEM;
381 goto err_free_fbdev;
382 }
383
384 fbdev->cache = devm_kmalloc(&client->dev, HT16K33_FB_SIZE, GFP_KERNEL);
385 if (!fbdev->cache) {
386 err = -ENOMEM;
387 goto err_fbdev_buffer;
388 }
389
390 fbdev->info = framebuffer_alloc(0, &client->dev);
391 if (!fbdev->info) {
392 err = -ENOMEM;
393 goto err_fbdev_buffer;
394 }
395
396 err = of_property_read_u32(node, "refresh-rate-hz",
397 &fbdev->refresh_rate);
398 if (err) {
399 dev_err(&client->dev, "refresh rate not specified\n");
400 goto err_fbdev_info;
401 }
402 fb_bl_default_curve(fbdev->info, 0, MIN_BRIGHTNESS, MAX_BRIGHTNESS);
403
404 INIT_DELAYED_WORK(&fbdev->work, ht16k33_fb_update);
405 fbdev->info->fbops = &ht16k33_fb_ops;
406 fbdev->info->screen_base = (char __iomem *) fbdev->buffer;
407 fbdev->info->screen_size = HT16K33_FB_SIZE;
408 fbdev->info->fix = ht16k33_fb_fix;
409 fbdev->info->var = ht16k33_fb_var;
410 fbdev->info->pseudo_palette = NULL;
411 fbdev->info->flags = FBINFO_FLAG_DEFAULT;
412 fbdev->info->par = priv;
413
414 err = register_framebuffer(fbdev->info);
415 if (err)
416 goto err_fbdev_info;
417
418 /* Keypad */
419 keypad->dev = devm_input_allocate_device(&client->dev);
420 if (!keypad->dev) {
421 err = -ENOMEM;
422 goto err_fbdev_unregister;
423 }
424
425 keypad->dev->name = DRIVER_NAME"-keypad";
426 keypad->dev->id.bustype = BUS_I2C;
427 keypad->dev->open = ht16k33_keypad_start;
428 keypad->dev->close = ht16k33_keypad_stop;
429
430 if (!of_get_property(node, "linux,no-autorepeat", NULL))
431 __set_bit(EV_REP, keypad->dev->evbit);
432
433 err = of_property_read_u32(node, "debounce-delay-ms",
434 &keypad->debounce_ms);
435 if (err) {
436 dev_err(&client->dev, "key debounce delay not specified\n");
437 goto err_fbdev_unregister;
438 }
439
440 err = devm_request_threaded_irq(&client->dev, client->irq, NULL,
441 ht16k33_irq_thread,
442 IRQF_TRIGGER_RISING | IRQF_ONESHOT,
443 DRIVER_NAME, priv);
444 if (err) {
445 dev_err(&client->dev, "irq request failed %d, error %d\n",
446 client->irq, err);
447 goto err_fbdev_unregister;
448 }
449
450 disable_irq_nosync(client->irq);
451 rows = HT16K33_MATRIX_KEYPAD_MAX_ROWS;
452 cols = HT16K33_MATRIX_KEYPAD_MAX_COLS;
453 err = matrix_keypad_parse_of_params(&client->dev, &rows, &cols);
454 if (err)
455 goto err_fbdev_unregister;
456
457 err = matrix_keypad_build_keymap(NULL, NULL, rows, cols, NULL,
458 keypad->dev);
459 if (err) {
460 dev_err(&client->dev, "failed to build keymap\n");
461 goto err_fbdev_unregister;
462 }
463
464 input_set_drvdata(keypad->dev, priv);
465 keypad->rows = rows;
466 keypad->cols = cols;
467 keypad->row_shift = get_count_order(cols);
468 INIT_DELAYED_WORK(&keypad->work, ht16k33_keypad_scan);
469
470 err = input_register_device(keypad->dev);
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_keypad_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_keypad_unregister:
506 input_unregister_device(keypad->dev);
507err_fbdev_unregister:
508 unregister_framebuffer(fbdev->info);
509err_fbdev_info:
510 framebuffer_release(fbdev->info);
511err_fbdev_buffer:
512 free_page((unsigned long) fbdev->buffer);
513err_free_fbdev:
514 kfree(fbdev);
515err_destroy_wq:
516 destroy_workqueue(priv->workqueue);
517
518 return err;
519}
520
521static int ht16k33_remove(struct i2c_client *client)
522{
523 struct ht16k33_priv *priv = i2c_get_clientdata(client);
524 struct ht16k33_keypad *keypad = &priv->keypad;
525 struct ht16k33_fbdev *fbdev = &priv->fbdev;
526
527 ht16k33_keypad_stop(keypad->dev);
528
529 cancel_delayed_work(&fbdev->work);
530 unregister_framebuffer(fbdev->info);
531 framebuffer_release(fbdev->info);
532 free_page((unsigned long) fbdev->buffer);
533
534 destroy_workqueue(priv->workqueue);
535 return 0;
536}
537
538static const struct i2c_device_id ht16k33_i2c_match[] = {
539 { "ht16k33", 0 },
540 { }
541};
542MODULE_DEVICE_TABLE(i2c, ht16k33_i2c_match);
543
544static const struct of_device_id ht16k33_of_match[] = {
545 { .compatible = "holtek,ht16k33", },
546 { }
547};
548MODULE_DEVICE_TABLE(of, ht16k33_of_match);
549
550static struct i2c_driver ht16k33_driver = {
551 .probe = ht16k33_probe,
552 .remove = ht16k33_remove,
553 .driver = {
554 .name = DRIVER_NAME,
555 .of_match_table = of_match_ptr(ht16k33_of_match),
556 },
557 .id_table = ht16k33_i2c_match,
558};
559module_i2c_driver(ht16k33_driver);
560
561MODULE_DESCRIPTION("Holtek HT16K33 driver");
562MODULE_LICENSE("GPL");
563MODULE_AUTHOR("Robin van der Gracht <robin@protonic.nl>");