auxdisplay: ht16k33: Driver for LED controller

Added a driver for the Holtek HT16K33 LED controller with keyscan.

Signed-off-by: Robin van der Gracht <robin@protonic.nl>
CC: Miguel Ojeda Sandonis <miguel.ojeda.sandonis@gmail.com>
Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

4 files changed, 615 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/display/ht16k33.txt b/Documentation/devicetree/bindings/display/ht16k33.txt
new file mode 100644
index 000000000000..8e5b30b87754
--- /dev/null
+++ b/Documentation/devicetree/bindings/display/ht16k33.txt
@@ -0,0 +1,42 @@
+Holtek ht16k33 RAM mapping 16*8 LED controller driver with keyscan
+-------------------------------------------------------------------------------
+
+Required properties:
+- compatible:           "holtek,ht16k33"
+- reg:                  I2C slave address of the chip.
+- interrupt-parent:     A phandle pointing to the interrupt controller
+                        serving the interrupt for this chip.
+- interrupts:           Interrupt specification for the key pressed interrupt.
+- refresh-rate-hz:      Display update interval in HZ.
+- debounce-delay-ms:    Debouncing interval time in milliseconds.
+- linux,keymap:         The keymap for keys as described in the binding
+                        document (devicetree/bindings/input/matrix-keymap.txt).
+
+Optional properties:
+- linux,no-autorepeat:  Disable keyrepeat.
+- default-brightness-level: Initial brightness level [0-15] (default: 15).
+
+Example:
+
+&i2c1 {
+        ht16k33: ht16k33@70 {
+                compatible = "holtek,ht16k33";
+                reg = <0x70>;
+                refresh-rate-hz = <20>;
+                debounce-delay-ms = <50>;
+                interrupt-parent = <&gpio4>;
+                interrupts = <5 (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_EDGE_RISING)>;
+                linux,keymap = <
+                        MATRIX_KEY(2, 0, KEY_F6)
+                        MATRIX_KEY(3, 0, KEY_F8)
+                        MATRIX_KEY(4, 0, KEY_F10)
+                        MATRIX_KEY(5, 0, KEY_F4)
+                        MATRIX_KEY(6, 0, KEY_F2)
+                        MATRIX_KEY(2, 1, KEY_F5)
+                        MATRIX_KEY(3, 1, KEY_F7)
+                        MATRIX_KEY(4, 1, KEY_F9)
+                        MATRIX_KEY(5, 1, KEY_F3)
+                        MATRIX_KEY(6, 1, KEY_F1)
+                >;
+        };
+};
diff --git a/drivers/auxdisplay/Kconfig b/drivers/auxdisplay/Kconfig
index 10e1b9eee10e..a230ea797b92 100644
--- a/drivers/auxdisplay/Kconfig
+++ b/drivers/auxdisplay/Kconfig
@@ -128,4 +128,13 @@ config IMG_ASCII_LCD
           development boards such as the MIPS Boston, MIPS Malta & MIPS SEAD3
           from Imagination Technologies.
 
+config HT16K33
+        tristate "Holtek Ht16K33 LED controller with keyscan"
+        depends on FB && OF && I2C && INPUT
+        select INPUT_MATRIXKMAP
+        select FB_BACKLIGHT
+        help
+          Say yes here to add support for Holtek HT16K33, RAM mapping 16*8
+          LED controller driver with keyscan.
+
 endif # AUXDISPLAY
diff --git a/drivers/auxdisplay/Makefile b/drivers/auxdisplay/Makefile
index 3127175c89df..cb3dd847713b 100644
--- a/drivers/auxdisplay/Makefile
+++ b/drivers/auxdisplay/Makefile
@@ -5,3 +5,4 @@
 obj-$(CONFIG_KS0108)            += ks0108.o
 obj-$(CONFIG_CFAG12864B)        += cfag12864b.o cfag12864bfb.o
 obj-$(CONFIG_IMG_ASCII_LCD)     += img-ascii-lcd.o
+obj-$(CONFIG_HT16K33)           += ht16k33.o
diff --git a/drivers/auxdisplay/ht16k33.c b/drivers/auxdisplay/ht16k33.c
new file mode 100644
index 000000000000..eeb323f56c07
--- /dev/null
+++ b/drivers/auxdisplay/ht16k33.c
@@ -0,0 +1,563 @@
+/*
+ * HT16K33 driver
+ *
+ * Author: Robin van der Gracht <robin@protonic.nl>
+ *
+ * Copyright: (C) 2016 Protonic Holland.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/i2c.h>
+#include <linux/of.h>
+#include <linux/fb.h>
+#include <linux/slab.h>
+#include <linux/backlight.h>
+#include <linux/input.h>
+#include <linux/input/matrix_keypad.h>
+#include <linux/workqueue.h>
+#include <linux/mm.h>
+
+/* 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 input_dev *dev;
+        spinlock_t lock;
+        struct delayed_work work;
+        uint32_t cols;
+        uint32_t rows;
+        uint32_t row_shift;
+        uint32_t debounce_ms;
+        uint16_t last_key_state[HT16K33_MATRIX_KEYPAD_MAX_COLS];
+};
+
+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;
+        struct workqueue_struct *workqueue;
+};
+
+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;
+
+        queue_delayed_work(priv->workqueue, &fbdev->work,
+                msecs_to_jiffies(HZ / fbdev->refresh_rate));
+}
+
+static void ht16k33_keypad_queue(struct ht16k33_priv *priv)
+{
+        struct ht16k33_keypad *keypad = &priv->keypad;
+
+        queue_delayed_work(priv->workqueue, &keypad->work,
+                msecs_to_jiffies(keypad->debounce_ms));
+}
+
+/*
+ * 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_keypad_start(struct input_dev *dev)
+{
+        struct ht16k33_priv *priv = input_get_drvdata(dev);
+        struct ht16k33_keypad *keypad = &priv->keypad;
+
+        /*
+         * Schedule an immediate key scan to capture current key state;
+         * columns will be activated and IRQs be enabled after the scan.
+         */
+        queue_delayed_work(priv->workqueue, &keypad->work, 0);
+        return 0;
+}
+
+static void ht16k33_keypad_stop(struct input_dev *dev)
+{
+        struct ht16k33_priv *priv = input_get_drvdata(dev);
+        struct ht16k33_keypad *keypad = &priv->keypad;
+
+        cancel_delayed_work(&keypad->work);
+        /*
+         * ht16k33_keypad_scan() will leave IRQs enabled;
+         * we should disable them now.
+         */
+        disable_irq_nosync(priv->client->irq);
+}
+
+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);
+}
+
+/*
+ * This gets the keys from keypad and reports it to input subsystem
+ */
+static void ht16k33_keypad_scan(struct work_struct *work)
+{
+        struct ht16k33_keypad *keypad =
+                container_of(work, struct ht16k33_keypad, work.work);
+        struct ht16k33_priv *priv =
+                container_of(keypad, struct ht16k33_priv, keypad);
+        const unsigned short *keycodes = keypad->dev->keycode;
+        uint16_t bits_changed, new_state[HT16K33_MATRIX_KEYPAD_MAX_COLS];
+        uint8_t data[HT16K33_MATRIX_KEYPAD_MAX_COLS * 2];
+        int row, col, code;
+        bool reschedule = false;
+
+        if (i2c_smbus_read_i2c_block_data(priv->client, 0x40, 6, data) != 6) {
+                dev_err(&priv->client->dev, "Failed to read key data\n");
+                goto end;
+        }
+
+        for (col = 0; col < keypad->cols; col++) {
+                new_state[col] = (data[col * 2 + 1] << 8) | data[col * 2];
+                if (new_state[col])
+                        reschedule = true;
+                bits_changed = keypad->last_key_state[col] ^ new_state[col];
+
+                while (bits_changed) {
+                        row = ffs(bits_changed) - 1;
+                        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));
+                        bits_changed &= ~BIT(row);
+                }
+        }
+        input_sync(keypad->dev);
+        memcpy(keypad->last_key_state, new_state, sizeof(new_state));
+
+end:
+        if (reschedule)
+                ht16k33_keypad_queue(priv);
+        else
+                enable_irq(priv->client->irq);
+}
+
+static irqreturn_t ht16k33_irq_thread(int irq, void *dev)
+{
+        struct ht16k33_priv *priv = dev;
+
+        disable_irq_nosync(priv->client->irq);
+        ht16k33_keypad_queue(priv);
+
+        return IRQ_HANDLED;
+}
+
+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,
+};
+
+static int ht16k33_probe(struct i2c_client *client,
+                                  const struct i2c_device_id *id)
+{
+        int err;
+        uint32_t rows, cols, dft_brightness;
+        struct backlight_device *bl;
+        struct backlight_properties bl_props;
+        struct ht16k33_priv *priv;
+        struct ht16k33_keypad *keypad;
+        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;
+        keypad = &priv->keypad;
+
+        priv->workqueue = create_singlethread_workqueue(DRIVER_NAME "-wq");
+        if (priv->workqueue == NULL)
+                return -ENOMEM;
+
+        err = ht16k33_initialize(priv);
+        if (err)
+                goto err_destroy_wq;
+
+        /* 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) {
+                err = -ENOMEM;
+                goto err_free_fbdev;
+        }
+
+        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;
+
+        /* Keypad */
+        keypad->dev = devm_input_allocate_device(&client->dev);
+        if (!keypad->dev) {
+                err = -ENOMEM;
+                goto err_fbdev_unregister;
+        }
+
+        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");
+                goto err_fbdev_unregister;
+        }
+
+        err = devm_request_threaded_irq(&client->dev, client->irq, NULL,
+                                        ht16k33_irq_thread,
+                                        IRQF_TRIGGER_RISING | IRQF_ONESHOT,
+                                        DRIVER_NAME, priv);
+        if (err) {
+                dev_err(&client->dev, "irq request failed %d, error %d\n",
+                        client->irq, err);
+                goto err_fbdev_unregister;
+        }
+
+        disable_irq_nosync(client->irq);
+        rows = HT16K33_MATRIX_KEYPAD_MAX_ROWS;
+        cols = HT16K33_MATRIX_KEYPAD_MAX_COLS;
+        err = matrix_keypad_parse_of_params(&client->dev, &rows, &cols);
+        if (err)
+                goto err_fbdev_unregister;
+
+        err = matrix_keypad_build_keymap(NULL, NULL, rows, cols, NULL,
+                                         keypad->dev);
+        if (err) {
+                dev_err(&client->dev, "failed to build keymap\n");
+                goto err_fbdev_unregister;
+        }
+
+        input_set_drvdata(keypad->dev, priv);
+        keypad->rows = rows;
+        keypad->cols = cols;
+        keypad->row_shift = get_count_order(cols);
+        INIT_DELAYED_WORK(&keypad->work, ht16k33_keypad_scan);
+
+        err = input_register_device(keypad->dev);
+        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_keypad_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_keypad_unregister:
+        input_unregister_device(keypad->dev);
+err_fbdev_unregister:
+        unregister_framebuffer(fbdev->info);
+err_fbdev_info:
+        framebuffer_release(fbdev->info);
+err_fbdev_buffer:
+        free_page((unsigned long) fbdev->buffer);
+err_free_fbdev:
+        kfree(fbdev);
+err_destroy_wq:
+        destroy_workqueue(priv->workqueue);
+
+        return err;
+}
+
+static int ht16k33_remove(struct i2c_client *client)
+{
+        struct ht16k33_priv *priv = i2c_get_clientdata(client);
+        struct ht16k33_keypad *keypad = &priv->keypad;
+        struct ht16k33_fbdev *fbdev = &priv->fbdev;
+
+        ht16k33_keypad_stop(keypad->dev);
+
+        cancel_delayed_work(&fbdev->work);
+        unregister_framebuffer(fbdev->info);
+        framebuffer_release(fbdev->info);
+        free_page((unsigned long) fbdev->buffer);
+
+        destroy_workqueue(priv->workqueue);
+        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 <robin@protonic.nl>");