1 // SPDX-License-Identifier: GPL-2.0
5 * Author: Robin van der Gracht <robin@protonic.nl>
7 * Copyright: (C) 2016 Protonic Holland.
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12 #include <linux/interrupt.h>
13 #include <linux/i2c.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>
24 #define REG_SYSTEM_SETUP 0x20
25 #define REG_SYSTEM_SETUP_OSC_ON BIT(0)
27 #define REG_DISPLAY_SETUP 0x80
28 #define REG_DISPLAY_SETUP_ON BIT(0)
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)
34 #define REG_BRIGHTNESS 0xE0
37 #define DRIVER_NAME "ht16k33"
39 #define MIN_BRIGHTNESS 0x1
40 #define MAX_BRIGHTNESS 0x10
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
47 #define BYTES_PER_ROW (HT16K33_MATRIX_LED_MAX_ROWS / 8)
48 #define HT16K33_FB_SIZE (HT16K33_MATRIX_LED_MAX_COLS * BYTES_PER_ROW)
50 struct ht16k33_keypad {
51 struct i2c_client *client;
52 struct input_dev *dev;
57 uint16_t last_key_state[HT16K33_MATRIX_KEYPAD_MAX_COLS];
59 wait_queue_head_t wait;
63 struct ht16k33_fbdev {
65 uint32_t refresh_rate;
68 struct delayed_work work;
72 struct i2c_client *client;
73 struct ht16k33_keypad keypad;
74 struct ht16k33_fbdev fbdev;
77 static const struct fb_fix_screeninfo ht16k33_fb_fix = {
79 .type = FB_TYPE_PACKED_PIXELS,
80 .visual = FB_VISUAL_MONO10,
84 .line_length = HT16K33_MATRIX_LED_MAX_ROWS,
85 .accel = FB_ACCEL_NONE,
88 static 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,
101 .vmode = FB_VMODE_NONINTERLACED,
104 static int ht16k33_display_on(struct ht16k33_priv *priv)
106 uint8_t data = REG_DISPLAY_SETUP | REG_DISPLAY_SETUP_ON;
108 return i2c_smbus_write_byte(priv->client, data);
111 static int ht16k33_display_off(struct ht16k33_priv *priv)
113 return i2c_smbus_write_byte(priv->client, REG_DISPLAY_SETUP);
116 static void ht16k33_fb_queue(struct ht16k33_priv *priv)
118 struct ht16k33_fbdev *fbdev = &priv->fbdev;
120 schedule_delayed_work(&fbdev->work, HZ / fbdev->refresh_rate);
124 * This gets the fb data from cache and copies it to ht16k33 display RAM
126 static void ht16k33_fb_update(struct work_struct *work)
128 struct ht16k33_fbdev *fbdev =
129 container_of(work, struct ht16k33_fbdev, work.work);
130 struct ht16k33_priv *priv =
131 container_of(fbdev, struct ht16k33_priv, fbdev);
134 int len, pos = 0, first = -1;
139 /* Search for the first byte with changes */
140 while (pos < HT16K33_FB_SIZE && first < 0) {
141 if (*(p1++) - *(p2++))
146 /* No changes found */
150 len = HT16K33_FB_SIZE - first;
151 p1 = fbdev->cache + HT16K33_FB_SIZE - 1;
152 p2 = fbdev->buffer + HT16K33_FB_SIZE - 1;
154 /* Determine i2c transfer length */
156 if (*(p1--) - *(p2--))
161 p1 = fbdev->cache + first;
162 p2 = fbdev->buffer + first;
163 if (!i2c_smbus_write_i2c_block_data(priv->client, first, len, p2))
166 ht16k33_fb_queue(priv);
169 static int ht16k33_initialize(struct ht16k33_priv *priv)
173 uint8_t data[HT16K33_MATRIX_LED_MAX_COLS * 2];
175 /* Clear RAM (8 * 16 bits) */
176 memset(data, 0, sizeof(data));
177 err = i2c_smbus_write_block_data(priv->client, 0, sizeof(data), data);
181 /* Turn on internal oscillator */
182 byte = REG_SYSTEM_SETUP_OSC_ON | REG_SYSTEM_SETUP;
183 err = i2c_smbus_write_byte(priv->client, byte);
187 /* Configure INT pin */
188 byte = REG_ROWINT_SET | REG_ROWINT_SET_INT_ACT_HIGH;
189 if (priv->client->irq > 0)
190 byte |= REG_ROWINT_SET_INT_EN;
191 return i2c_smbus_write_byte(priv->client, byte);
194 static int ht16k33_bl_update_status(struct backlight_device *bl)
196 int brightness = bl->props.brightness;
197 struct ht16k33_priv *priv = bl_get_data(bl);
199 if (bl->props.power != FB_BLANK_UNBLANK ||
200 bl->props.fb_blank != FB_BLANK_UNBLANK ||
201 bl->props.state & BL_CORE_FBBLANK || brightness == 0) {
202 return ht16k33_display_off(priv);
205 ht16k33_display_on(priv);
206 return i2c_smbus_write_byte(priv->client,
207 REG_BRIGHTNESS | (brightness - 1));
210 static int ht16k33_bl_check_fb(struct backlight_device *bl, struct fb_info *fi)
212 struct ht16k33_priv *priv = bl_get_data(bl);
214 return (fi == NULL) || (fi->par == priv);
217 static const struct backlight_ops ht16k33_bl_ops = {
218 .update_status = ht16k33_bl_update_status,
219 .check_fb = ht16k33_bl_check_fb,
222 static int ht16k33_mmap(struct fb_info *info, struct vm_area_struct *vma)
224 struct ht16k33_priv *priv = info->par;
225 struct page *pages = virt_to_page(priv->fbdev.buffer);
227 return vm_map_pages_zero(vma, &pages, 1);
230 static const struct fb_ops ht16k33_fb_ops = {
231 .owner = THIS_MODULE,
232 .fb_read = fb_sys_read,
233 .fb_write = fb_sys_write,
234 .fb_fillrect = sys_fillrect,
235 .fb_copyarea = sys_copyarea,
236 .fb_imageblit = sys_imageblit,
237 .fb_mmap = ht16k33_mmap,
241 * This gets the keys from keypad and reports it to input subsystem.
242 * Returns true if a key is pressed.
244 static bool ht16k33_keypad_scan(struct ht16k33_keypad *keypad)
246 const unsigned short *keycodes = keypad->dev->keycode;
247 u16 new_state[HT16K33_MATRIX_KEYPAD_MAX_COLS];
248 __le16 data[HT16K33_MATRIX_KEYPAD_MAX_COLS];
249 unsigned long bits_changed;
252 bool pressed = false;
254 rc = i2c_smbus_read_i2c_block_data(keypad->client, 0x40,
255 sizeof(data), (u8 *)data);
256 if (rc != sizeof(data)) {
257 dev_err(&keypad->client->dev,
258 "Failed to read key data, rc=%d\n", rc);
262 for (col = 0; col < keypad->cols; col++) {
263 new_state[col] = le16_to_cpu(data[col]);
266 bits_changed = keypad->last_key_state[col] ^ new_state[col];
268 for_each_set_bit(row, &bits_changed, BITS_PER_LONG) {
269 code = MATRIX_SCAN_CODE(row, col, keypad->row_shift);
270 input_event(keypad->dev, EV_MSC, MSC_SCAN, code);
271 input_report_key(keypad->dev, keycodes[code],
272 new_state[col] & BIT(row));
275 input_sync(keypad->dev);
276 memcpy(keypad->last_key_state, new_state, sizeof(u16) * keypad->cols);
281 static irqreturn_t ht16k33_keypad_irq_thread(int irq, void *dev)
283 struct ht16k33_keypad *keypad = dev;
286 wait_event_timeout(keypad->wait, keypad->stopped,
287 msecs_to_jiffies(keypad->debounce_ms));
290 } while (ht16k33_keypad_scan(keypad));
295 static int ht16k33_keypad_start(struct input_dev *dev)
297 struct ht16k33_keypad *keypad = input_get_drvdata(dev);
299 keypad->stopped = false;
301 enable_irq(keypad->client->irq);
306 static void ht16k33_keypad_stop(struct input_dev *dev)
308 struct ht16k33_keypad *keypad = input_get_drvdata(dev);
310 keypad->stopped = true;
312 wake_up(&keypad->wait);
313 disable_irq(keypad->client->irq);
316 static int ht16k33_keypad_probe(struct i2c_client *client,
317 struct ht16k33_keypad *keypad)
319 struct device_node *node = client->dev.of_node;
320 u32 rows = HT16K33_MATRIX_KEYPAD_MAX_ROWS;
321 u32 cols = HT16K33_MATRIX_KEYPAD_MAX_COLS;
324 keypad->client = client;
325 init_waitqueue_head(&keypad->wait);
327 keypad->dev = devm_input_allocate_device(&client->dev);
331 input_set_drvdata(keypad->dev, keypad);
333 keypad->dev->name = DRIVER_NAME"-keypad";
334 keypad->dev->id.bustype = BUS_I2C;
335 keypad->dev->open = ht16k33_keypad_start;
336 keypad->dev->close = ht16k33_keypad_stop;
338 if (!of_get_property(node, "linux,no-autorepeat", NULL))
339 __set_bit(EV_REP, keypad->dev->evbit);
341 err = of_property_read_u32(node, "debounce-delay-ms",
342 &keypad->debounce_ms);
344 dev_err(&client->dev, "key debounce delay not specified\n");
348 err = matrix_keypad_parse_of_params(&client->dev, &rows, &cols);
351 if (rows > HT16K33_MATRIX_KEYPAD_MAX_ROWS ||
352 cols > HT16K33_MATRIX_KEYPAD_MAX_COLS) {
353 dev_err(&client->dev, "%u rows or %u cols out of range in DT\n",
360 keypad->row_shift = get_count_order(cols);
362 err = matrix_keypad_build_keymap(NULL, NULL, rows, cols, NULL,
365 dev_err(&client->dev, "failed to build keymap\n");
369 err = devm_request_threaded_irq(&client->dev, client->irq,
370 NULL, ht16k33_keypad_irq_thread,
371 IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
372 DRIVER_NAME, keypad);
374 dev_err(&client->dev, "irq request failed %d, error %d\n",
379 ht16k33_keypad_stop(keypad->dev);
381 err = input_register_device(keypad->dev);
388 static int ht16k33_probe(struct i2c_client *client,
389 const struct i2c_device_id *id)
392 uint32_t dft_brightness;
393 struct backlight_device *bl;
394 struct backlight_properties bl_props;
395 struct ht16k33_priv *priv;
396 struct ht16k33_fbdev *fbdev;
397 struct device_node *node = client->dev.of_node;
399 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
400 dev_err(&client->dev, "i2c_check_functionality error\n");
404 priv = devm_kzalloc(&client->dev, sizeof(*priv), GFP_KERNEL);
408 priv->client = client;
409 i2c_set_clientdata(client, priv);
410 fbdev = &priv->fbdev;
412 err = ht16k33_initialize(priv);
416 /* Framebuffer (2 bytes per column) */
417 BUILD_BUG_ON(PAGE_SIZE < HT16K33_FB_SIZE);
418 fbdev->buffer = (unsigned char *) get_zeroed_page(GFP_KERNEL);
422 fbdev->cache = devm_kmalloc(&client->dev, HT16K33_FB_SIZE, GFP_KERNEL);
425 goto err_fbdev_buffer;
428 fbdev->info = framebuffer_alloc(0, &client->dev);
431 goto err_fbdev_buffer;
434 err = of_property_read_u32(node, "refresh-rate-hz",
435 &fbdev->refresh_rate);
437 dev_err(&client->dev, "refresh rate not specified\n");
440 fb_bl_default_curve(fbdev->info, 0, MIN_BRIGHTNESS, MAX_BRIGHTNESS);
442 INIT_DELAYED_WORK(&fbdev->work, ht16k33_fb_update);
443 fbdev->info->fbops = &ht16k33_fb_ops;
444 fbdev->info->screen_base = (char __iomem *) fbdev->buffer;
445 fbdev->info->screen_size = HT16K33_FB_SIZE;
446 fbdev->info->fix = ht16k33_fb_fix;
447 fbdev->info->var = ht16k33_fb_var;
448 fbdev->info->pseudo_palette = NULL;
449 fbdev->info->flags = FBINFO_FLAG_DEFAULT;
450 fbdev->info->par = priv;
452 err = register_framebuffer(fbdev->info);
457 if (client->irq > 0) {
458 err = ht16k33_keypad_probe(client, &priv->keypad);
460 goto err_fbdev_unregister;
464 memset(&bl_props, 0, sizeof(struct backlight_properties));
465 bl_props.type = BACKLIGHT_RAW;
466 bl_props.max_brightness = MAX_BRIGHTNESS;
468 bl = devm_backlight_device_register(&client->dev, DRIVER_NAME"-bl",
470 &ht16k33_bl_ops, &bl_props);
472 dev_err(&client->dev, "failed to register backlight\n");
474 goto err_fbdev_unregister;
477 err = of_property_read_u32(node, "default-brightness-level",
480 dft_brightness = MAX_BRIGHTNESS;
481 } else if (dft_brightness > MAX_BRIGHTNESS) {
482 dev_warn(&client->dev,
483 "invalid default brightness level: %u, using %u\n",
484 dft_brightness, MAX_BRIGHTNESS);
485 dft_brightness = MAX_BRIGHTNESS;
488 bl->props.brightness = dft_brightness;
489 ht16k33_bl_update_status(bl);
491 ht16k33_fb_queue(priv);
494 err_fbdev_unregister:
495 unregister_framebuffer(fbdev->info);
497 framebuffer_release(fbdev->info);
499 free_page((unsigned long) fbdev->buffer);
504 static int ht16k33_remove(struct i2c_client *client)
506 struct ht16k33_priv *priv = i2c_get_clientdata(client);
507 struct ht16k33_fbdev *fbdev = &priv->fbdev;
509 cancel_delayed_work_sync(&fbdev->work);
510 unregister_framebuffer(fbdev->info);
511 framebuffer_release(fbdev->info);
512 free_page((unsigned long) fbdev->buffer);
517 static const struct i2c_device_id ht16k33_i2c_match[] = {
521 MODULE_DEVICE_TABLE(i2c, ht16k33_i2c_match);
523 static const struct of_device_id ht16k33_of_match[] = {
524 { .compatible = "holtek,ht16k33", },
527 MODULE_DEVICE_TABLE(of, ht16k33_of_match);
529 static struct i2c_driver ht16k33_driver = {
530 .probe = ht16k33_probe,
531 .remove = ht16k33_remove,
534 .of_match_table = of_match_ptr(ht16k33_of_match),
536 .id_table = ht16k33_i2c_match,
538 module_i2c_driver(ht16k33_driver);
540 MODULE_DESCRIPTION("Holtek HT16K33 driver");
541 MODULE_LICENSE("GPL");
542 MODULE_AUTHOR("Robin van der Gracht <robin@protonic.nl>");