4 * Author: Robin van der Gracht <robin@protonic.nl>
6 * Copyright: (C) 2016 Protonic Holland.
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.
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.
18 #include <linux/kernel.h>
19 #include <linux/module.h>
20 #include <linux/interrupt.h>
21 #include <linux/i2c.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>
32 #define REG_SYSTEM_SETUP 0x20
33 #define REG_SYSTEM_SETUP_OSC_ON BIT(0)
35 #define REG_DISPLAY_SETUP 0x80
36 #define REG_DISPLAY_SETUP_ON BIT(0)
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)
42 #define REG_BRIGHTNESS 0xE0
45 #define DRIVER_NAME "ht16k33"
47 #define MIN_BRIGHTNESS 0x1
48 #define MAX_BRIGHTNESS 0x10
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
55 #define BYTES_PER_ROW (HT16K33_MATRIX_LED_MAX_ROWS / 8)
56 #define HT16K33_FB_SIZE (HT16K33_MATRIX_LED_MAX_COLS * BYTES_PER_ROW)
58 struct ht16k33_keypad {
59 struct i2c_client *client;
60 struct input_dev *dev;
65 uint16_t last_key_state[HT16K33_MATRIX_KEYPAD_MAX_COLS];
67 wait_queue_head_t wait;
71 struct ht16k33_fbdev {
73 uint32_t refresh_rate;
76 struct delayed_work work;
80 struct i2c_client *client;
81 struct ht16k33_keypad keypad;
82 struct ht16k33_fbdev fbdev;
85 static struct fb_fix_screeninfo ht16k33_fb_fix = {
87 .type = FB_TYPE_PACKED_PIXELS,
88 .visual = FB_VISUAL_MONO10,
92 .line_length = HT16K33_MATRIX_LED_MAX_ROWS,
93 .accel = FB_ACCEL_NONE,
96 static 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,
103 .green = { 0, 1, 0 },
109 .vmode = FB_VMODE_NONINTERLACED,
112 static int ht16k33_display_on(struct ht16k33_priv *priv)
114 uint8_t data = REG_DISPLAY_SETUP | REG_DISPLAY_SETUP_ON;
116 return i2c_smbus_write_byte(priv->client, data);
119 static int ht16k33_display_off(struct ht16k33_priv *priv)
121 return i2c_smbus_write_byte(priv->client, REG_DISPLAY_SETUP);
124 static void ht16k33_fb_queue(struct ht16k33_priv *priv)
126 struct ht16k33_fbdev *fbdev = &priv->fbdev;
128 schedule_delayed_work(&fbdev->work, HZ / fbdev->refresh_rate);
132 * This gets the fb data from cache and copies it to ht16k33 display RAM
134 static void ht16k33_fb_update(struct work_struct *work)
136 struct ht16k33_fbdev *fbdev =
137 container_of(work, struct ht16k33_fbdev, work.work);
138 struct ht16k33_priv *priv =
139 container_of(fbdev, struct ht16k33_priv, fbdev);
142 int len, pos = 0, first = -1;
147 /* Search for the first byte with changes */
148 while (pos < HT16K33_FB_SIZE && first < 0) {
149 if (*(p1++) - *(p2++))
154 /* No changes found */
158 len = HT16K33_FB_SIZE - first;
159 p1 = fbdev->cache + HT16K33_FB_SIZE - 1;
160 p2 = fbdev->buffer + HT16K33_FB_SIZE - 1;
162 /* Determine i2c transfer length */
164 if (*(p1--) - *(p2--))
169 p1 = fbdev->cache + first;
170 p2 = fbdev->buffer + first;
171 if (!i2c_smbus_write_i2c_block_data(priv->client, first, len, p2))
174 ht16k33_fb_queue(priv);
177 static int ht16k33_initialize(struct ht16k33_priv *priv)
181 uint8_t data[HT16K33_MATRIX_LED_MAX_COLS * 2];
183 /* Clear RAM (8 * 16 bits) */
184 memset(data, 0, sizeof(data));
185 err = i2c_smbus_write_block_data(priv->client, 0, sizeof(data), data);
189 /* Turn on internal oscillator */
190 byte = REG_SYSTEM_SETUP_OSC_ON | REG_SYSTEM_SETUP;
191 err = i2c_smbus_write_byte(priv->client, byte);
195 /* Configure INT pin */
196 byte = REG_ROWINT_SET | REG_ROWINT_SET_INT_ACT_HIGH;
197 if (priv->client->irq > 0)
198 byte |= REG_ROWINT_SET_INT_EN;
199 return i2c_smbus_write_byte(priv->client, byte);
202 static int ht16k33_bl_update_status(struct backlight_device *bl)
204 int brightness = bl->props.brightness;
205 struct ht16k33_priv *priv = bl_get_data(bl);
207 if (bl->props.power != FB_BLANK_UNBLANK ||
208 bl->props.fb_blank != FB_BLANK_UNBLANK ||
209 bl->props.state & BL_CORE_FBBLANK || brightness == 0) {
210 return ht16k33_display_off(priv);
213 ht16k33_display_on(priv);
214 return i2c_smbus_write_byte(priv->client,
215 REG_BRIGHTNESS | (brightness - 1));
218 static int ht16k33_bl_check_fb(struct backlight_device *bl, struct fb_info *fi)
220 struct ht16k33_priv *priv = bl_get_data(bl);
222 return (fi == NULL) || (fi->par == priv);
225 static const struct backlight_ops ht16k33_bl_ops = {
226 .update_status = ht16k33_bl_update_status,
227 .check_fb = ht16k33_bl_check_fb,
230 static int ht16k33_mmap(struct fb_info *info, struct vm_area_struct *vma)
232 struct ht16k33_priv *priv = info->par;
234 return vm_insert_page(vma, vma->vm_start,
235 virt_to_page(priv->fbdev.buffer));
238 static struct fb_ops ht16k33_fb_ops = {
239 .owner = THIS_MODULE,
240 .fb_read = fb_sys_read,
241 .fb_write = fb_sys_write,
242 .fb_fillrect = sys_fillrect,
243 .fb_copyarea = sys_copyarea,
244 .fb_imageblit = sys_imageblit,
245 .fb_mmap = ht16k33_mmap,
249 * This gets the keys from keypad and reports it to input subsystem.
250 * Returns true if a key is pressed.
252 static bool ht16k33_keypad_scan(struct ht16k33_keypad *keypad)
254 const unsigned short *keycodes = keypad->dev->keycode;
255 u16 new_state[HT16K33_MATRIX_KEYPAD_MAX_COLS];
256 __le16 data[HT16K33_MATRIX_KEYPAD_MAX_COLS];
257 unsigned long bits_changed;
260 bool pressed = false;
262 rc = i2c_smbus_read_i2c_block_data(keypad->client, 0x40,
263 sizeof(data), (u8 *)data);
264 if (rc != sizeof(data)) {
265 dev_err(&keypad->client->dev,
266 "Failed to read key data, rc=%d\n", rc);
270 for (col = 0; col < keypad->cols; col++) {
271 new_state[col] = le16_to_cpu(data[col]);
274 bits_changed = keypad->last_key_state[col] ^ new_state[col];
276 for_each_set_bit(row, &bits_changed, BITS_PER_LONG) {
277 code = MATRIX_SCAN_CODE(row, col, keypad->row_shift);
278 input_event(keypad->dev, EV_MSC, MSC_SCAN, code);
279 input_report_key(keypad->dev, keycodes[code],
280 new_state[col] & BIT(row));
283 input_sync(keypad->dev);
284 memcpy(keypad->last_key_state, new_state, sizeof(u16) * keypad->cols);
289 static irqreturn_t ht16k33_keypad_irq_thread(int irq, void *dev)
291 struct ht16k33_keypad *keypad = dev;
294 wait_event_timeout(keypad->wait, keypad->stopped,
295 msecs_to_jiffies(keypad->debounce_ms));
298 } while (ht16k33_keypad_scan(keypad));
303 static int ht16k33_keypad_start(struct input_dev *dev)
305 struct ht16k33_keypad *keypad = input_get_drvdata(dev);
307 keypad->stopped = false;
309 enable_irq(keypad->client->irq);
314 static void ht16k33_keypad_stop(struct input_dev *dev)
316 struct ht16k33_keypad *keypad = input_get_drvdata(dev);
318 keypad->stopped = true;
320 wake_up(&keypad->wait);
321 disable_irq(keypad->client->irq);
324 static int ht16k33_keypad_probe(struct i2c_client *client,
325 struct ht16k33_keypad *keypad)
327 struct device_node *node = client->dev.of_node;
328 u32 rows = HT16K33_MATRIX_KEYPAD_MAX_ROWS;
329 u32 cols = HT16K33_MATRIX_KEYPAD_MAX_COLS;
332 keypad->client = client;
333 init_waitqueue_head(&keypad->wait);
335 keypad->dev = devm_input_allocate_device(&client->dev);
339 input_set_drvdata(keypad->dev, keypad);
341 keypad->dev->name = DRIVER_NAME"-keypad";
342 keypad->dev->id.bustype = BUS_I2C;
343 keypad->dev->open = ht16k33_keypad_start;
344 keypad->dev->close = ht16k33_keypad_stop;
346 if (!of_get_property(node, "linux,no-autorepeat", NULL))
347 __set_bit(EV_REP, keypad->dev->evbit);
349 err = of_property_read_u32(node, "debounce-delay-ms",
350 &keypad->debounce_ms);
352 dev_err(&client->dev, "key debounce delay not specified\n");
356 err = matrix_keypad_parse_of_params(&client->dev, &rows, &cols);
359 if (rows > HT16K33_MATRIX_KEYPAD_MAX_ROWS ||
360 cols > HT16K33_MATRIX_KEYPAD_MAX_COLS) {
361 dev_err(&client->dev, "%u rows or %u cols out of range in DT\n",
368 keypad->row_shift = get_count_order(cols);
370 err = matrix_keypad_build_keymap(NULL, NULL, rows, cols, NULL,
373 dev_err(&client->dev, "failed to build keymap\n");
377 err = devm_request_threaded_irq(&client->dev, client->irq,
378 NULL, ht16k33_keypad_irq_thread,
379 IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
380 DRIVER_NAME, keypad);
382 dev_err(&client->dev, "irq request failed %d, error %d\n",
387 ht16k33_keypad_stop(keypad->dev);
389 err = input_register_device(keypad->dev);
396 static int ht16k33_probe(struct i2c_client *client,
397 const struct i2c_device_id *id)
400 uint32_t dft_brightness;
401 struct backlight_device *bl;
402 struct backlight_properties bl_props;
403 struct ht16k33_priv *priv;
404 struct ht16k33_fbdev *fbdev;
405 struct device_node *node = client->dev.of_node;
407 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
408 dev_err(&client->dev, "i2c_check_functionality error\n");
412 if (client->irq <= 0) {
413 dev_err(&client->dev, "No IRQ specified\n");
417 priv = devm_kzalloc(&client->dev, sizeof(*priv), GFP_KERNEL);
421 priv->client = client;
422 i2c_set_clientdata(client, priv);
423 fbdev = &priv->fbdev;
425 err = ht16k33_initialize(priv);
429 /* Framebuffer (2 bytes per column) */
430 BUILD_BUG_ON(PAGE_SIZE < HT16K33_FB_SIZE);
431 fbdev->buffer = (unsigned char *) get_zeroed_page(GFP_KERNEL);
435 fbdev->cache = devm_kmalloc(&client->dev, HT16K33_FB_SIZE, GFP_KERNEL);
438 goto err_fbdev_buffer;
441 fbdev->info = framebuffer_alloc(0, &client->dev);
444 goto err_fbdev_buffer;
447 err = of_property_read_u32(node, "refresh-rate-hz",
448 &fbdev->refresh_rate);
450 dev_err(&client->dev, "refresh rate not specified\n");
453 fb_bl_default_curve(fbdev->info, 0, MIN_BRIGHTNESS, MAX_BRIGHTNESS);
455 INIT_DELAYED_WORK(&fbdev->work, ht16k33_fb_update);
456 fbdev->info->fbops = &ht16k33_fb_ops;
457 fbdev->info->screen_base = (char __iomem *) fbdev->buffer;
458 fbdev->info->screen_size = HT16K33_FB_SIZE;
459 fbdev->info->fix = ht16k33_fb_fix;
460 fbdev->info->var = ht16k33_fb_var;
461 fbdev->info->pseudo_palette = NULL;
462 fbdev->info->flags = FBINFO_FLAG_DEFAULT;
463 fbdev->info->par = priv;
465 err = register_framebuffer(fbdev->info);
469 err = ht16k33_keypad_probe(client, &priv->keypad);
471 goto err_fbdev_unregister;
474 memset(&bl_props, 0, sizeof(struct backlight_properties));
475 bl_props.type = BACKLIGHT_RAW;
476 bl_props.max_brightness = MAX_BRIGHTNESS;
478 bl = devm_backlight_device_register(&client->dev, DRIVER_NAME"-bl",
480 &ht16k33_bl_ops, &bl_props);
482 dev_err(&client->dev, "failed to register backlight\n");
484 goto err_fbdev_unregister;
487 err = of_property_read_u32(node, "default-brightness-level",
490 dft_brightness = MAX_BRIGHTNESS;
491 } else if (dft_brightness > MAX_BRIGHTNESS) {
492 dev_warn(&client->dev,
493 "invalid default brightness level: %u, using %u\n",
494 dft_brightness, MAX_BRIGHTNESS);
495 dft_brightness = MAX_BRIGHTNESS;
498 bl->props.brightness = dft_brightness;
499 ht16k33_bl_update_status(bl);
501 ht16k33_fb_queue(priv);
504 err_fbdev_unregister:
505 unregister_framebuffer(fbdev->info);
507 framebuffer_release(fbdev->info);
509 free_page((unsigned long) fbdev->buffer);
514 static int ht16k33_remove(struct i2c_client *client)
516 struct ht16k33_priv *priv = i2c_get_clientdata(client);
517 struct ht16k33_fbdev *fbdev = &priv->fbdev;
519 cancel_delayed_work_sync(&fbdev->work);
520 unregister_framebuffer(fbdev->info);
521 framebuffer_release(fbdev->info);
522 free_page((unsigned long) fbdev->buffer);
527 static const struct i2c_device_id ht16k33_i2c_match[] = {
531 MODULE_DEVICE_TABLE(i2c, ht16k33_i2c_match);
533 static const struct of_device_id ht16k33_of_match[] = {
534 { .compatible = "holtek,ht16k33", },
537 MODULE_DEVICE_TABLE(of, ht16k33_of_match);
539 static struct i2c_driver ht16k33_driver = {
540 .probe = ht16k33_probe,
541 .remove = ht16k33_remove,
544 .of_match_table = of_match_ptr(ht16k33_of_match),
546 .id_table = ht16k33_i2c_match,
548 module_i2c_driver(ht16k33_driver);
550 MODULE_DESCRIPTION("Holtek HT16K33 driver");
551 MODULE_LICENSE("GPL");
552 MODULE_AUTHOR("Robin van der Gracht <robin@protonic.nl>");