[PATCH v4 2/2] auxdisplay: ht16k33: Driver for LED controller
From: Robin van der Gracht
Date: Wed Mar 16 2016 - 11:54:09 EST
This is a driver for the Holtek HT16K33 RAM mapping LED controller with keyscan.
Signed-off-by: Robin van der Gracht <robin@xxxxxxxxxxx>
---
Changes in v4:
- Removed trailing dot from patch title
- Removed unused defines
- Fixed brightness range (0 was presumed to be off but its 1/16 duty cycle)
- No longer checking 'reschedule' before setting it in ht16k33_keypad_scan()
- Use more efficient ffs() to find changed rows in ht16k33_keypad_scan()
- Use BIT macro in ht16k33_keypad_scan()
- Removed extra space in return line from ht16k33_bl_check_fb()
- Removed redundant 'Out of Memory' prints from ht16k33_probe()
- Changed bustype from BUS_HOST to BUS_I2C
.../devicetree/bindings/display/ht16k33.txt | 42 ++
drivers/auxdisplay/Kconfig | 9 +
drivers/auxdisplay/Makefile | 1 +
drivers/auxdisplay/ht16k33.c | 563 +++++++++++++++++++++
4 files changed, 615 insertions(+)
create mode 100644 Documentation/devicetree/bindings/display/ht16k33.txt
create mode 100644 drivers/auxdisplay/ht16k33.c
diff --git a/Documentation/devicetree/bindings/display/ht16k33.txt b/Documentation/devicetree/bindings/display/ht16k33.txt
new file mode 100644
index 0000000..20ef996
--- /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: "ht,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 microseconds.
+- 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 = "ht,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_F0)
+ 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 c07e725..75ad4f5 100644
--- a/drivers/auxdisplay/Kconfig
+++ b/drivers/auxdisplay/Kconfig
@@ -119,4 +119,13 @@ config CFAG12864B_RATE
If you compile this as a module, you can still override this
value using the module parameters.
+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 8a8936a..d7c9ef5 100644
--- a/drivers/auxdisplay/Makefile
+++ b/drivers/auxdisplay/Makefile
@@ -4,3 +4,4 @@
obj-$(CONFIG_KS0108) += ks0108.o
obj-$(CONFIG_CFAG12864B) += cfag12864b.o cfag12864bfb.o
+obj-$(CONFIG_HT16K33) += ht16k33.o
diff --git a/drivers/auxdisplay/ht16k33.c b/drivers/auxdisplay/ht16k33.c
new file mode 100644
index 0000000..3d61b19
--- /dev/null
+++ b/drivers/auxdisplay/ht16k33.c
@@ -0,0 +1,563 @@
+/*
+ * HT16K33 driver
+ *
+ * Author: Robin van der Gracht <robin@xxxxxxxxxxx>
+ *
+ * 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 HT16K33_FB_SIZE (HT16K33_MATRIX_LED_MAX_COLS * 2)
+#define BYTES_PER_ROW (HT16K33_MATRIX_LED_MAX_ROWS / 8)
+
+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 = "ht,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@xxxxxxxxxxx>");
--
2.5.0