// SPDX-License-Identifier: GPL-2.0 /* * HT16K33 driver * * Author: Robin van der Gracht * * Copyright: (C) 2016 Protonic Holland. */ #include #include #include #include #include #include #include #include #include #include #include #include /* Registers */ #define REG_SYSTEM_SETUP 0x20 #define REG_SYSTEM_SETUP_OSC_ON BIT(0) #define REG_DISPLAY_SETUP 0x80 #define REG_DISPLAY_SETUP_ON BIT(0) #define REG_ROWINT_SET 0xA0 #define REG_ROWINT_SET_INT_EN BIT(0) #define REG_ROWINT_SET_INT_ACT_HIGH BIT(1) #define REG_BRIGHTNESS 0xE0 /* Defines */ #define DRIVER_NAME "ht16k33" #define MIN_BRIGHTNESS 0x1 #define MAX_BRIGHTNESS 0x10 #define HT16K33_MATRIX_LED_MAX_COLS 8 #define HT16K33_MATRIX_LED_MAX_ROWS 16 #define HT16K33_MATRIX_KEYPAD_MAX_COLS 3 #define HT16K33_MATRIX_KEYPAD_MAX_ROWS 12 #define BYTES_PER_ROW (HT16K33_MATRIX_LED_MAX_ROWS / 8) #define HT16K33_FB_SIZE (HT16K33_MATRIX_LED_MAX_COLS * BYTES_PER_ROW) struct ht16k33_keypad { struct i2c_client *client; struct input_dev *dev; uint32_t cols; uint32_t rows; uint32_t row_shift; uint32_t debounce_ms; uint16_t last_key_state[HT16K33_MATRIX_KEYPAD_MAX_COLS]; wait_queue_head_t wait; bool stopped; }; struct ht16k33_fbdev { struct fb_info *info; uint32_t refresh_rate; uint8_t *buffer; uint8_t *cache; struct delayed_work work; }; struct ht16k33_priv { struct i2c_client *client; struct ht16k33_keypad keypad; struct ht16k33_fbdev fbdev; }; static struct fb_fix_screeninfo ht16k33_fb_fix = { .id = DRIVER_NAME, .type = FB_TYPE_PACKED_PIXELS, .visual = FB_VISUAL_MONO10, .xpanstep = 0, .ypanstep = 0, .ywrapstep = 0, .line_length = HT16K33_MATRIX_LED_MAX_ROWS, .accel = FB_ACCEL_NONE, }; static struct fb_var_screeninfo ht16k33_fb_var = { .xres = HT16K33_MATRIX_LED_MAX_ROWS, .yres = HT16K33_MATRIX_LED_MAX_COLS, .xres_virtual = HT16K33_MATRIX_LED_MAX_ROWS, .yres_virtual = HT16K33_MATRIX_LED_MAX_COLS, .bits_per_pixel = 1, .red = { 0, 1, 0 }, .green = { 0, 1, 0 }, .blue = { 0, 1, 0 }, .left_margin = 0, .right_margin = 0, .upper_margin = 0, .lower_margin = 0, .vmode = FB_VMODE_NONINTERLACED, }; static int ht16k33_display_on(struct ht16k33_priv *priv) { uint8_t data = REG_DISPLAY_SETUP | REG_DISPLAY_SETUP_ON; return i2c_smbus_write_byte(priv->client, data); } static int ht16k33_display_off(struct ht16k33_priv *priv) { return i2c_smbus_write_byte(priv->client, REG_DISPLAY_SETUP); } static void ht16k33_fb_queue(struct ht16k33_priv *priv) { struct ht16k33_fbdev *fbdev = &priv->fbdev; schedule_delayed_work(&fbdev->work, HZ / fbdev->refresh_rate); } /* * This gets the fb data from cache and copies it to ht16k33 display RAM */ static void ht16k33_fb_update(struct work_struct *work) { struct ht16k33_fbdev *fbdev = container_of(work, struct ht16k33_fbdev, work.work); struct ht16k33_priv *priv = container_of(fbdev, struct ht16k33_priv, fbdev); uint8_t *p1, *p2; int len, pos = 0, first = -1; p1 = fbdev->cache; p2 = fbdev->buffer; /* Search for the first byte with changes */ while (pos < HT16K33_FB_SIZE && first < 0) { if (*(p1++) - *(p2++)) first = pos; pos++; } /* No changes found */ if (first < 0) goto requeue; len = HT16K33_FB_SIZE - first; p1 = fbdev->cache + HT16K33_FB_SIZE - 1; p2 = fbdev->buffer + HT16K33_FB_SIZE - 1; /* Determine i2c transfer length */ while (len > 1) { if (*(p1--) - *(p2--)) break; len--; } p1 = fbdev->cache + first; p2 = fbdev->buffer + first; if (!i2c_smbus_write_i2c_block_data(priv->client, first, len, p2)) memcpy(p1, p2, len); requeue: ht16k33_fb_queue(priv); } static int ht16k33_initialize(struct ht16k33_priv *priv) { uint8_t byte; int err; uint8_t data[HT16K33_MATRIX_LED_MAX_COLS * 2]; /* Clear RAM (8 * 16 bits) */ memset(data, 0, sizeof(data)); err = i2c_smbus_write_block_data(priv->client, 0, sizeof(data), data); if (err) return err; /* Turn on internal oscillator */ byte = REG_SYSTEM_SETUP_OSC_ON | REG_SYSTEM_SETUP; err = i2c_smbus_write_byte(priv->client, byte); if (err) return err; /* Configure INT pin */ byte = REG_ROWINT_SET | REG_ROWINT_SET_INT_ACT_HIGH; if (priv->client->irq > 0) byte |= REG_ROWINT_SET_INT_EN; return i2c_smbus_write_byte(priv->client, byte); } static int ht16k33_bl_update_status(struct backlight_device *bl) { int brightness = bl->props.brightness; struct ht16k33_priv *priv = bl_get_data(bl); if (bl->props.power != FB_BLANK_UNBLANK || bl->props.fb_blank != FB_BLANK_UNBLANK || bl->props.state & BL_CORE_FBBLANK || brightness == 0) { return ht16k33_display_off(priv); } ht16k33_display_on(priv); return i2c_smbus_write_byte(priv->client, REG_BRIGHTNESS | (brightness - 1)); } static int ht16k33_bl_check_fb(struct backlight_device *bl, struct fb_info *fi) { struct ht16k33_priv *priv = bl_get_data(bl); return (fi == NULL) || (fi->par == priv); } static const struct backlight_ops ht16k33_bl_ops = { .update_status = ht16k33_bl_update_status, .check_fb = ht16k33_bl_check_fb, }; static int ht16k33_mmap(struct fb_info *info, struct vm_area_struct *vma) { struct ht16k33_priv *priv = info->par; return vm_insert_page(vma, vma->vm_start, virt_to_page(priv->fbdev.buffer)); } static struct fb_ops ht16k33_fb_ops = { .owner = THIS_MODULE, .fb_read = fb_sys_read, .fb_write = fb_sys_write, .fb_fillrect = sys_fillrect, .fb_copyarea = sys_copyarea, .fb_imageblit = sys_imageblit, .fb_mmap = ht16k33_mmap, }; /* * This gets the keys from keypad and reports it to input subsystem. * Returns true if a key is pressed. */ static bool ht16k33_keypad_scan(struct ht16k33_keypad *keypad) { const unsigned short *keycodes = keypad->dev->keycode; u16 new_state[HT16K33_MATRIX_KEYPAD_MAX_COLS]; __le16 data[HT16K33_MATRIX_KEYPAD_MAX_COLS]; unsigned long bits_changed; int row, col, code; int rc; bool pressed = false; rc = i2c_smbus_read_i2c_block_data(keypad->client, 0x40, sizeof(data), (u8 *)data); if (rc != sizeof(data)) { dev_err(&keypad->client->dev, "Failed to read key data, rc=%d\n", rc); return false; } for (col = 0; col < keypad->cols; col++) { new_state[col] = le16_to_cpu(data[col]); if (new_state[col]) pressed = true; bits_changed = keypad->last_key_state[col] ^ new_state[col]; for_each_set_bit(row, &bits_changed, BITS_PER_LONG) { code = MATRIX_SCAN_CODE(row, col, keypad->row_shift); input_event(keypad->dev, EV_MSC, MSC_SCAN, code); input_report_key(keypad->dev, keycodes[code], new_state[col] & BIT(row)); } } input_sync(keypad->dev); memcpy(keypad->last_key_state, new_state, sizeof(u16) * keypad->cols); return pressed; } static irqreturn_t ht16k33_keypad_irq_thread(int irq, void *dev) { struct ht16k33_keypad *keypad = dev; do { wait_event_timeout(keypad->wait, keypad->stopped, msecs_to_jiffies(keypad->debounce_ms)); if (keypad->stopped) break; } while (ht16k33_keypad_scan(keypad)); return IRQ_HANDLED; } static int ht16k33_keypad_start(struct input_dev *dev) { struct ht16k33_keypad *keypad = input_get_drvdata(dev); keypad->stopped = false; mb(); enable_irq(keypad->client->irq); return 0; } static void ht16k33_keypad_stop(struct input_dev *dev) { struct ht16k33_keypad *keypad = input_get_drvdata(dev); keypad->stopped = true; mb(); wake_up(&keypad->wait); disable_irq(keypad->client->irq); } static int ht16k33_keypad_probe(struct i2c_client *client, struct ht16k33_keypad *keypad) { struct device_node *node = client->dev.of_node; u32 rows = HT16K33_MATRIX_KEYPAD_MAX_ROWS; u32 cols = HT16K33_MATRIX_KEYPAD_MAX_COLS; int err; keypad->client = client; init_waitqueue_head(&keypad->wait); keypad->dev = devm_input_allocate_device(&client->dev); if (!keypad->dev) return -ENOMEM; input_set_drvdata(keypad->dev, keypad); keypad->dev->name = DRIVER_NAME"-keypad"; keypad->dev->id.bustype = BUS_I2C; keypad->dev->open = ht16k33_keypad_start; keypad->dev->close = ht16k33_keypad_stop; if (!of_get_property(node, "linux,no-autorepeat", NULL)) __set_bit(EV_REP, keypad->dev->evbit); err = of_property_read_u32(node, "debounce-delay-ms", &keypad->debounce_ms); if (err) { dev_err(&client->dev, "key debounce delay not specified\n"); return err; } err = matrix_keypad_parse_of_params(&client->dev, &rows, &cols); if (err) return err; if (rows > HT16K33_MATRIX_KEYPAD_MAX_ROWS || cols > HT16K33_MATRIX_KEYPAD_MAX_COLS) { dev_err(&client->dev, "%u rows or %u cols out of range in DT\n", rows, cols); return -ERANGE; } keypad->rows = rows; keypad->cols = cols; keypad->row_shift = get_count_order(cols); err = matrix_keypad_build_keymap(NULL, NULL, rows, cols, NULL, keypad->dev); if (err) { dev_err(&client->dev, "failed to build keymap\n"); return err; } err = devm_request_threaded_irq(&client->dev, client->irq, NULL, ht16k33_keypad_irq_thread, IRQF_TRIGGER_HIGH | IRQF_ONESHOT, DRIVER_NAME, keypad); if (err) { dev_err(&client->dev, "irq request failed %d, error %d\n", client->irq, err); return err; } ht16k33_keypad_stop(keypad->dev); err = input_register_device(keypad->dev); if (err) return err; return 0; } static int ht16k33_probe(struct i2c_client *client, const struct i2c_device_id *id) { int err; uint32_t dft_brightness; struct backlight_device *bl; struct backlight_properties bl_props; struct ht16k33_priv *priv; struct ht16k33_fbdev *fbdev; struct device_node *node = client->dev.of_node; if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { dev_err(&client->dev, "i2c_check_functionality error\n"); return -EIO; } if (client->irq <= 0) { dev_err(&client->dev, "No IRQ specified\n"); return -EINVAL; } priv = devm_kzalloc(&client->dev, sizeof(*priv), GFP_KERNEL); if (!priv) return -ENOMEM; priv->client = client; i2c_set_clientdata(client, priv); fbdev = &priv->fbdev; err = ht16k33_initialize(priv); if (err) return err; /* Framebuffer (2 bytes per column) */ BUILD_BUG_ON(PAGE_SIZE < HT16K33_FB_SIZE); fbdev->buffer = (unsigned char *) get_zeroed_page(GFP_KERNEL); if (!fbdev->buffer) return -ENOMEM; fbdev->cache = devm_kmalloc(&client->dev, HT16K33_FB_SIZE, GFP_KERNEL); if (!fbdev->cache) { err = -ENOMEM; goto err_fbdev_buffer; } fbdev->info = framebuffer_alloc(0, &client->dev); if (!fbdev->info) { err = -ENOMEM; goto err_fbdev_buffer; } err = of_property_read_u32(node, "refresh-rate-hz", &fbdev->refresh_rate); if (err) { dev_err(&client->dev, "refresh rate not specified\n"); goto err_fbdev_info; } fb_bl_default_curve(fbdev->info, 0, MIN_BRIGHTNESS, MAX_BRIGHTNESS); INIT_DELAYED_WORK(&fbdev->work, ht16k33_fb_update); fbdev->info->fbops = &ht16k33_fb_ops; fbdev->info->screen_base = (char __iomem *) fbdev->buffer; fbdev->info->screen_size = HT16K33_FB_SIZE; fbdev->info->fix = ht16k33_fb_fix; fbdev->info->var = ht16k33_fb_var; fbdev->info->pseudo_palette = NULL; fbdev->info->flags = FBINFO_FLAG_DEFAULT; fbdev->info->par = priv; err = register_framebuffer(fbdev->info); if (err) goto err_fbdev_info; err = ht16k33_keypad_probe(client, &priv->keypad); if (err) goto err_fbdev_unregister; /* Backlight */ memset(&bl_props, 0, sizeof(struct backlight_properties)); bl_props.type = BACKLIGHT_RAW; bl_props.max_brightness = MAX_BRIGHTNESS; bl = devm_backlight_device_register(&client->dev, DRIVER_NAME"-bl", &client->dev, priv, &ht16k33_bl_ops, &bl_props); if (IS_ERR(bl)) { dev_err(&client->dev, "failed to register backlight\n"); err = PTR_ERR(bl); goto err_fbdev_unregister; } err = of_property_read_u32(node, "default-brightness-level", &dft_brightness); if (err) { dft_brightness = MAX_BRIGHTNESS; } else if (dft_brightness > MAX_BRIGHTNESS) { dev_warn(&client->dev, "invalid default brightness level: %u, using %u\n", dft_brightness, MAX_BRIGHTNESS); dft_brightness = MAX_BRIGHTNESS; } bl->props.brightness = dft_brightness; ht16k33_bl_update_status(bl); ht16k33_fb_queue(priv); return 0; err_fbdev_unregister: unregister_framebuffer(fbdev->info); err_fbdev_info: framebuffer_release(fbdev->info); err_fbdev_buffer: free_page((unsigned long) fbdev->buffer); return err; } static int ht16k33_remove(struct i2c_client *client) { struct ht16k33_priv *priv = i2c_get_clientdata(client); struct ht16k33_fbdev *fbdev = &priv->fbdev; cancel_delayed_work_sync(&fbdev->work); unregister_framebuffer(fbdev->info); framebuffer_release(fbdev->info); free_page((unsigned long) fbdev->buffer); return 0; } static const struct i2c_device_id ht16k33_i2c_match[] = { { "ht16k33", 0 }, { } }; MODULE_DEVICE_TABLE(i2c, ht16k33_i2c_match); static const struct of_device_id ht16k33_of_match[] = { { .compatible = "holtek,ht16k33", }, { } }; MODULE_DEVICE_TABLE(of, ht16k33_of_match); static struct i2c_driver ht16k33_driver = { .probe = ht16k33_probe, .remove = ht16k33_remove, .driver = { .name = DRIVER_NAME, .of_match_table = of_match_ptr(ht16k33_of_match), }, .id_table = ht16k33_i2c_match, }; module_i2c_driver(ht16k33_driver); MODULE_DESCRIPTION("Holtek HT16K33 driver"); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Robin van der Gracht ");