Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 835 insertions, 0 deletions

diff --git a/drivers/auxdisplay/ht16k33.c b/drivers/auxdisplay/ht16k33.c
new file mode 100644
index 000000000..02425991c
--- /dev/null
+++ b/drivers/auxdisplay/ht16k33.c
@@ -0,0 +1,835 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * HT16K33 driver
+ *
+ * Author: Robin van der Gracht <robin@protonic.nl>
+ *
+ * Copyright: (C) 2016 Protonic Holland.
+ * Copyright (C) 2021 Glider bv
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/i2c.h>
+#include <linux/property.h>
+#include <linux/fb.h>
+#include <linux/backlight.h>
+#include <linux/input.h>
+#include <linux/input/matrix_keypad.h>
+#include <linux/leds.h>
+#include <linux/workqueue.h>
+#include <linux/mm.h>
+
+#include <linux/map_to_7segment.h>
+#include <linux/map_to_14segment.h>
+
+#include <asm/unaligned.h>
+
+#include "line-display.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_DISPLAY_SETUP_BLINK_OFF	(0 << 1)
+#define REG_DISPLAY_SETUP_BLINK_2HZ	(1 << 1)
+#define REG_DISPLAY_SETUP_BLINK_1HZ	(2 << 1)
+#define REG_DISPLAY_SETUP_BLINK_0HZ5	(3 << 1)
+
+#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)
+
+enum display_type {
+	DISP_MATRIX = 0,
+	DISP_QUAD_7SEG,
+	DISP_QUAD_14SEG,
+};
+
+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 ht16k33_seg {
+	struct linedisp linedisp;
+	union {
+		struct seg7_conversion_map seg7;
+		struct seg14_conversion_map seg14;
+	} map;
+	unsigned int map_size;
+	char curr[4];
+};
+
+struct ht16k33_priv {
+	struct i2c_client *client;
+	struct delayed_work work;
+	struct led_classdev led;
+	struct ht16k33_keypad keypad;
+	union {
+		struct ht16k33_fbdev fbdev;
+		struct ht16k33_seg seg;
+	};
+	enum display_type type;
+	uint8_t blink;
+};
+
+static const 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 const 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 const SEG7_DEFAULT_MAP(initial_map_seg7);
+static const SEG14_DEFAULT_MAP(initial_map_seg14);
+
+static ssize_t map_seg_show(struct device *dev, struct device_attribute *attr,
+			    char *buf)
+{
+	struct ht16k33_priv *priv = dev_get_drvdata(dev);
+
+	memcpy(buf, &priv->seg.map, priv->seg.map_size);
+	return priv->seg.map_size;
+}
+
+static ssize_t map_seg_store(struct device *dev, struct device_attribute *attr,
+			     const char *buf, size_t cnt)
+{
+	struct ht16k33_priv *priv = dev_get_drvdata(dev);
+
+	if (cnt != priv->seg.map_size)
+		return -EINVAL;
+
+	memcpy(&priv->seg.map, buf, cnt);
+	return cnt;
+}
+
+static DEVICE_ATTR(map_seg7, 0644, map_seg_show, map_seg_store);
+static DEVICE_ATTR(map_seg14, 0644, map_seg_show, map_seg_store);
+
+static int ht16k33_display_on(struct ht16k33_priv *priv)
+{
+	uint8_t data = REG_DISPLAY_SETUP | REG_DISPLAY_SETUP_ON | priv->blink;
+
+	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 int ht16k33_brightness_set(struct ht16k33_priv *priv,
+				  unsigned int brightness)
+{
+	int err;
+
+	if (brightness == 0) {
+		priv->blink = REG_DISPLAY_SETUP_BLINK_OFF;
+		return ht16k33_display_off(priv);
+	}
+
+	err = ht16k33_display_on(priv);
+	if (err)
+		return err;
+
+	return i2c_smbus_write_byte(priv->client,
+				    REG_BRIGHTNESS | (brightness - 1));
+}
+
+static int ht16k33_brightness_set_blocking(struct led_classdev *led_cdev,
+					   enum led_brightness brightness)
+{
+	struct ht16k33_priv *priv = container_of(led_cdev, struct ht16k33_priv,
+						 led);
+
+	return ht16k33_brightness_set(priv, brightness);
+}
+
+static int ht16k33_blink_set(struct led_classdev *led_cdev,
+			     unsigned long *delay_on, unsigned long *delay_off)
+{
+	struct ht16k33_priv *priv = container_of(led_cdev, struct ht16k33_priv,
+						 led);
+	unsigned int delay;
+	uint8_t blink;
+	int err;
+
+	if (!*delay_on && !*delay_off) {
+		blink = REG_DISPLAY_SETUP_BLINK_1HZ;
+		delay = 1000;
+	} else if (*delay_on <= 750) {
+		blink = REG_DISPLAY_SETUP_BLINK_2HZ;
+		delay = 500;
+	} else if (*delay_on <= 1500) {
+		blink = REG_DISPLAY_SETUP_BLINK_1HZ;
+		delay = 1000;
+	} else {
+		blink = REG_DISPLAY_SETUP_BLINK_0HZ5;
+		delay = 2000;
+	}
+
+	err = i2c_smbus_write_byte(priv->client,
+				   REG_DISPLAY_SETUP | REG_DISPLAY_SETUP_ON |
+				   blink);
+	if (err)
+		return err;
+
+	priv->blink = blink;
+	*delay_on = *delay_off = delay;
+	return 0;
+}
+
+static void ht16k33_fb_queue(struct ht16k33_priv *priv)
+{
+	struct ht16k33_fbdev *fbdev = &priv->fbdev;
+
+	schedule_delayed_work(&priv->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_priv *priv = container_of(work, struct ht16k33_priv,
+						 work.work);
+	struct ht16k33_fbdev *fbdev = &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 data[HT16K33_FB_SIZE];
+	uint8_t byte;
+	int err;
+
+	/* 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_brightness_set(priv, brightness);
+}
+
+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,
+};
+
+/*
+ * Blank events will be passed to the actual device handling the backlight when
+ * we return zero here.
+ */
+static int ht16k33_blank(int blank, struct fb_info *info)
+{
+	return 0;
+}
+
+static int ht16k33_mmap(struct fb_info *info, struct vm_area_struct *vma)
+{
+	struct ht16k33_priv *priv = info->par;
+	struct page *pages = virt_to_page(priv->fbdev.buffer);
+
+	return vm_map_pages_zero(vma, &pages, 1);
+}
+
+static const struct fb_ops ht16k33_fb_ops = {
+	.owner = THIS_MODULE,
+	.fb_read = fb_sys_read,
+	.fb_write = fb_sys_write,
+	.fb_blank = ht16k33_blank,
+	.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 void ht16k33_linedisp_update(struct linedisp *linedisp)
+{
+	struct ht16k33_priv *priv = container_of(linedisp, struct ht16k33_priv,
+						 seg.linedisp);
+
+	schedule_delayed_work(&priv->work, 0);
+}
+
+static void ht16k33_seg7_update(struct work_struct *work)
+{
+	struct ht16k33_priv *priv = container_of(work, struct ht16k33_priv,
+						 work.work);
+	struct ht16k33_seg *seg = &priv->seg;
+	char *s = seg->curr;
+	uint8_t buf[9];
+
+	buf[0] = map_to_seg7(&seg->map.seg7, *s++);
+	buf[1] = 0;
+	buf[2] = map_to_seg7(&seg->map.seg7, *s++);
+	buf[3] = 0;
+	buf[4] = 0;
+	buf[5] = 0;
+	buf[6] = map_to_seg7(&seg->map.seg7, *s++);
+	buf[7] = 0;
+	buf[8] = map_to_seg7(&seg->map.seg7, *s++);
+
+	i2c_smbus_write_i2c_block_data(priv->client, 0, ARRAY_SIZE(buf), buf);
+}
+
+static void ht16k33_seg14_update(struct work_struct *work)
+{
+	struct ht16k33_priv *priv = container_of(work, struct ht16k33_priv,
+						 work.work);
+	struct ht16k33_seg *seg = &priv->seg;
+	char *s = seg->curr;
+	uint8_t buf[8];
+
+	put_unaligned_le16(map_to_seg14(&seg->map.seg14, *s++), buf);
+	put_unaligned_le16(map_to_seg14(&seg->map.seg14, *s++), buf + 2);
+	put_unaligned_le16(map_to_seg14(&seg->map.seg14, *s++), buf + 4);
+	put_unaligned_le16(map_to_seg14(&seg->map.seg14, *s++), buf + 6);
+
+	i2c_smbus_write_i2c_block_data(priv->client, 0, ARRAY_SIZE(buf), buf);
+}
+
+static int ht16k33_led_probe(struct device *dev, struct led_classdev *led,
+			     unsigned int brightness)
+{
+	struct led_init_data init_data = {};
+	int err;
+
+	/* The LED is optional */
+	init_data.fwnode = device_get_named_child_node(dev, "led");
+	if (!init_data.fwnode)
+		return 0;
+
+	init_data.devicename = "auxdisplay";
+	init_data.devname_mandatory = true;
+
+	led->brightness_set_blocking = ht16k33_brightness_set_blocking;
+	led->blink_set = ht16k33_blink_set;
+	led->flags = LED_CORE_SUSPENDRESUME;
+	led->brightness = brightness;
+	led->max_brightness = MAX_BRIGHTNESS;
+
+	err = devm_led_classdev_register_ext(dev, led, &init_data);
+	if (err)
+		dev_err(dev, "Failed to register LED\n");
+
+	return err;
+}
+
+static int ht16k33_keypad_probe(struct i2c_client *client,
+				struct ht16k33_keypad *keypad)
+{
+	struct device *dev = &client->dev;
+	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(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 (!device_property_read_bool(dev, "linux,no-autorepeat"))
+		__set_bit(EV_REP, keypad->dev->evbit);
+
+	err = device_property_read_u32(dev, "debounce-delay-ms",
+				       &keypad->debounce_ms);
+	if (err) {
+		dev_err(dev, "key debounce delay not specified\n");
+		return err;
+	}
+
+	err = matrix_keypad_parse_properties(dev, &rows, &cols);
+	if (err)
+		return err;
+	if (rows > HT16K33_MATRIX_KEYPAD_MAX_ROWS ||
+	    cols > HT16K33_MATRIX_KEYPAD_MAX_COLS) {
+		dev_err(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(dev, "failed to build keymap\n");
+		return err;
+	}
+
+	err = devm_request_threaded_irq(dev, client->irq, NULL,
+					ht16k33_keypad_irq_thread,
+					IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
+					DRIVER_NAME, keypad);
+	if (err) {
+		dev_err(dev, "irq request failed %d, error %d\n", client->irq,
+			err);
+		return err;
+	}
+
+	ht16k33_keypad_stop(keypad->dev);
+
+	return input_register_device(keypad->dev);
+}
+
+static int ht16k33_fbdev_probe(struct device *dev, struct ht16k33_priv *priv,
+			       uint32_t brightness)
+{
+	struct ht16k33_fbdev *fbdev = &priv->fbdev;
+	struct backlight_device *bl = NULL;
+	int err;
+
+	if (priv->led.dev) {
+		err = ht16k33_brightness_set(priv, brightness);
+		if (err)
+			return err;
+	} else {
+		/* backwards compatibility with DT lacking an led subnode */
+		struct backlight_properties bl_props;
+
+		memset(&bl_props, 0, sizeof(struct backlight_properties));
+		bl_props.type = BACKLIGHT_RAW;
+		bl_props.max_brightness = MAX_BRIGHTNESS;
+
+		bl = devm_backlight_device_register(dev, DRIVER_NAME"-bl", dev,
+						    priv, &ht16k33_bl_ops,
+						    &bl_props);
+		if (IS_ERR(bl)) {
+			dev_err(dev, "failed to register backlight\n");
+			return PTR_ERR(bl);
+		}
+
+		bl->props.brightness = brightness;
+		ht16k33_bl_update_status(bl);
+	}
+
+	/* 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(dev, HT16K33_FB_SIZE, GFP_KERNEL);
+	if (!fbdev->cache) {
+		err = -ENOMEM;
+		goto err_fbdev_buffer;
+	}
+
+	fbdev->info = framebuffer_alloc(0, dev);
+	if (!fbdev->info) {
+		err = -ENOMEM;
+		goto err_fbdev_buffer;
+	}
+
+	err = device_property_read_u32(dev, "refresh-rate-hz",
+				       &fbdev->refresh_rate);
+	if (err) {
+		dev_err(dev, "refresh rate not specified\n");
+		goto err_fbdev_info;
+	}
+	fb_bl_default_curve(fbdev->info, 0, MIN_BRIGHTNESS, MAX_BRIGHTNESS);
+
+	INIT_DELAYED_WORK(&priv->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->bl_dev = bl;
+	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;
+
+	ht16k33_fb_queue(priv);
+	return 0;
+
+err_fbdev_info:
+	framebuffer_release(fbdev->info);
+err_fbdev_buffer:
+	free_page((unsigned long) fbdev->buffer);
+
+	return err;
+}
+
+static int ht16k33_seg_probe(struct device *dev, struct ht16k33_priv *priv,
+			     uint32_t brightness)
+{
+	struct ht16k33_seg *seg = &priv->seg;
+	int err;
+
+	err = ht16k33_brightness_set(priv, brightness);
+	if (err)
+		return err;
+
+	switch (priv->type) {
+	case DISP_MATRIX:
+		/* not handled here */
+		err = -EINVAL;
+		break;
+
+	case DISP_QUAD_7SEG:
+		INIT_DELAYED_WORK(&priv->work, ht16k33_seg7_update);
+		seg->map.seg7 = initial_map_seg7;
+		seg->map_size = sizeof(seg->map.seg7);
+		err = device_create_file(dev, &dev_attr_map_seg7);
+		break;
+
+	case DISP_QUAD_14SEG:
+		INIT_DELAYED_WORK(&priv->work, ht16k33_seg14_update);
+		seg->map.seg14 = initial_map_seg14;
+		seg->map_size = sizeof(seg->map.seg14);
+		err = device_create_file(dev, &dev_attr_map_seg14);
+		break;
+	}
+	if (err)
+		return err;
+
+	err = linedisp_register(&seg->linedisp, dev, 4, seg->curr,
+				ht16k33_linedisp_update);
+	if (err)
+		goto err_remove_map_file;
+
+	return 0;
+
+err_remove_map_file:
+	device_remove_file(dev, &dev_attr_map_seg7);
+	device_remove_file(dev, &dev_attr_map_seg14);
+	return err;
+}
+
+static int ht16k33_probe(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	const struct of_device_id *id;
+	struct ht16k33_priv *priv;
+	uint32_t dft_brightness;
+	int err;
+
+	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
+		dev_err(dev, "i2c_check_functionality error\n");
+		return -EIO;
+	}
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->client = client;
+	id = i2c_of_match_device(dev->driver->of_match_table, client);
+	if (id)
+		priv->type = (uintptr_t)id->data;
+	i2c_set_clientdata(client, priv);
+
+	err = ht16k33_initialize(priv);
+	if (err)
+		return err;
+
+	err = device_property_read_u32(dev, "default-brightness-level",
+				       &dft_brightness);
+	if (err) {
+		dft_brightness = MAX_BRIGHTNESS;
+	} else if (dft_brightness > MAX_BRIGHTNESS) {
+		dev_warn(dev,
+			 "invalid default brightness level: %u, using %u\n",
+			 dft_brightness, MAX_BRIGHTNESS);
+		dft_brightness = MAX_BRIGHTNESS;
+	}
+
+	/* LED */
+	err = ht16k33_led_probe(dev, &priv->led, dft_brightness);
+	if (err)
+		return err;
+
+	/* Keypad */
+	if (client->irq > 0) {
+		err = ht16k33_keypad_probe(client, &priv->keypad);
+		if (err)
+			return err;
+	}
+
+	switch (priv->type) {
+	case DISP_MATRIX:
+		/* Frame Buffer Display */
+		err = ht16k33_fbdev_probe(dev, priv, dft_brightness);
+		break;
+
+	case DISP_QUAD_7SEG:
+	case DISP_QUAD_14SEG:
+		/* Segment Display */
+		err = ht16k33_seg_probe(dev, priv, dft_brightness);
+		break;
+	}
+	return err;
+}
+
+static void ht16k33_remove(struct i2c_client *client)
+{
+	struct ht16k33_priv *priv = i2c_get_clientdata(client);
+	struct ht16k33_fbdev *fbdev = &priv->fbdev;
+
+	cancel_delayed_work_sync(&priv->work);
+
+	switch (priv->type) {
+	case DISP_MATRIX:
+		unregister_framebuffer(fbdev->info);
+		framebuffer_release(fbdev->info);
+		free_page((unsigned long)fbdev->buffer);
+		break;
+
+	case DISP_QUAD_7SEG:
+	case DISP_QUAD_14SEG:
+		linedisp_unregister(&priv->seg.linedisp);
+		device_remove_file(&client->dev, &dev_attr_map_seg7);
+		device_remove_file(&client->dev, &dev_attr_map_seg14);
+		break;
+	}
+}
+
+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[] = {
+	{
+		/* 0.56" 4-Digit 7-Segment FeatherWing Display (Red) */
+		.compatible = "adafruit,3108", .data = (void *)DISP_QUAD_7SEG,
+	}, {
+		/* 0.54" Quad Alphanumeric FeatherWing Display (Red) */
+		.compatible = "adafruit,3130", .data = (void *)DISP_QUAD_14SEG,
+	}, {
+		/* Generic, assumed Dot-Matrix Display */
+		.compatible = "holtek,ht16k33", .data = (void *)DISP_MATRIX,
+	},
+	{ }
+};
+MODULE_DEVICE_TABLE(of, ht16k33_of_match);
+
+static struct i2c_driver ht16k33_driver = {
+	.probe_new	= ht16k33_probe,
+	.remove		= ht16k33_remove,
+	.driver		= {
+		.name		= DRIVER_NAME,
+		.of_match_table	= 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>");