// SPDX-License-Identifier: GPL-2.0
/*
* HT16K33 driver
*
* Author: Robin van der Gracht <[email protected]>
*
* 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/container_of.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 <linux/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_priv {
struct i2c_client *client;
struct delayed_work work;
struct led_classdev led;
struct ht16k33_keypad keypad;
union {
struct ht16k33_fbdev fbdev;
struct linedisp linedisp;
};
enum display_type type;
uint8_t blink;
};
#define ht16k33_work_to_priv(p) \
container_of(p, struct ht16k33_priv, work.work)
#define ht16k33_led_to_priv(p) \
container_of(p, struct ht16k33_priv, led)
#define ht16k33_linedisp_to_priv(p) \
container_of(p, struct ht16k33_priv, linedisp)
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 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 = ht16k33_led_to_priv(led_cdev);
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 = ht16k33_led_to_priv(led_cdev);
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 = ht16k33_work_to_priv(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)
{
const int brightness = backlight_get_brightness(bl);
struct ht16k33_priv *priv = bl_get_data(bl);
return ht16k33_brightness_set(priv, brightness);
}
static const struct backlight_ops ht16k33_bl_ops = {
.update_status = ht16k33_bl_update_status,
};
/*
* 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);
vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot);
return vm_map_pages_zero(vma, &pages, 1);
}
static const struct fb_ops ht16k33_fb_ops = {
.owner = THIS_MODULE,
__FB_DEFAULT_SYSMEM_OPS_RDWR,
.fb_blank = ht16k33_blank,
__FB_DEFAULT_SYSMEM_OPS_DRAW,
.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_seg7_update(struct work_struct *work)
{
struct ht16k33_priv *priv = ht16k33_work_to_priv(work);
struct linedisp_map *map = priv->linedisp.map;
char *s = priv->linedisp.buf;
uint8_t buf[9];
buf[0] = map_to_seg7(&map->map.seg7, *s++);
buf[1] = 0;
buf[2] = map_to_seg7(&map->map.seg7, *s++);
buf[3] = 0;
buf[4] = 0;
buf[5] = 0;
buf[6] = map_to_seg7(&map->map.seg7, *s++);
buf[7] = 0;
buf[8] = map_to_seg7(&map->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 = ht16k33_work_to_priv(work);
struct linedisp_map *map = priv->linedisp.map;
char *s = priv->linedisp.buf;
uint8_t buf[8];
put_unaligned_le16(map_to_seg14(&map->map.seg14, *s++), buf + 0);
put_unaligned_le16(map_to_seg14(&map->map.seg14, *s++), buf + 2);
put_unaligned_le16(map_to_seg14(&map->map.seg14, *s++), buf + 4);
put_unaligned_le16(map_to_seg14(&map->map.seg14, *s++), buf + 6);
i2c_smbus_write_i2c_block_data(priv->client, 0, ARRAY_SIZE(buf), buf);
}
static int ht16k33_linedisp_get_map_type(struct linedisp *linedisp)
{
struct ht16k33_priv *priv = ht16k33_linedisp_to_priv(linedisp);
switch (priv->type) {
case DISP_QUAD_7SEG:
INIT_DELAYED_WORK(&priv->work, ht16k33_seg7_update);
return LINEDISP_MAP_SEG7;
case DISP_QUAD_14SEG:
INIT_DELAYED_WORK(&priv->work, ht16k33_seg14_update);
return LINEDISP_MAP_SEG14;
default:
return -EINVAL;
}
}
static void ht16k33_linedisp_update(struct linedisp *linedisp)
{
struct ht16k33_priv *priv = ht16k33_linedisp_to_priv(linedisp);
schedule_delayed_work(&priv->work, 0);
}
static const struct linedisp_ops ht16k33_linedisp_ops = {
.get_map_type = ht16k33_linedisp_get_map_type,
.update = ht16k33_linedisp_update,
};
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);
fwnode_handle_put(init_data.fwnode);
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->flags |= FBINFO_VIRTFB;
fbdev->info->screen_buffer = 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->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 linedisp *linedisp = &priv->linedisp;
int err;
err = ht16k33_brightness_set(priv, brightness);
if (err)
return err;
return linedisp_register(linedisp, dev, 4, &ht16k33_linedisp_ops);
}
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;
default:
return -EINVAL;
}
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->linedisp);
break;
default:
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 = 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_IMPORT_NS(LINEDISP);
MODULE_AUTHOR("Robin van der Gracht <[email protected]>");
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