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auxdisplay: ht16k33: Add support for segment displays

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The Holtek HT16K33 LED controller is not only used for driving
dot-matrix displays, but also for driving segment displays.

Add support for 4-digit 7-segment and quad 14-segment alphanumeric
displays, like the Adafruit 7-segment and 14-segment display backpack
and FeatherWing expansion boards.  Use the character line display core
support to display a message, which will be scrolled if it doesn't fit.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Robin van der Gracht <robin@protonic.nl>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
This commit is contained in:
Geert Uytterhoeven 2021-10-19 16:45:17 +02:00 committed by Miguel Ojeda
parent fcbb3c356e
commit a0428724cf
2 changed files with 190 additions and 7 deletions
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1
drivers/auxdisplay/Kconfig
View file

@ -176,6 +176,7 @@ config HT16K33
select FB_SYS_IMAGEBLIT
select INPUT_MATRIXKMAP
select FB_BACKLIGHT
select LINEDISP
help
Say yes here to add support for Holtek HT16K33, RAM mapping 16*8
LED controller driver with keyscan.

196
drivers/auxdisplay/ht16k33.c
View file

@ -5,6 +5,7 @@
* Author: Robin van der Gracht <robin@protonic.nl>
*
* Copyright: (C) 2016 Protonic Holland.
* Copyright (C) 2021 Glider bv
*/
#include <linux/kernel.h>
@ -20,6 +21,13 @@
#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)
@ -47,6 +55,12 @@
#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;
@ -67,11 +81,25 @@ struct ht16k33_fbdev {
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 ht16k33_keypad keypad;
struct ht16k33_fbdev fbdev;
union {
struct ht16k33_fbdev fbdev;
struct ht16k33_seg seg;
};
enum display_type type;
};
static const struct fb_fix_screeninfo ht16k33_fb_fix = {
@ -101,6 +129,33 @@ static const struct fb_var_screeninfo ht16k33_fb_var = {
.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;
@ -335,6 +390,51 @@ static void ht16k33_keypad_stop(struct input_dev *dev)
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_keypad_probe(struct i2c_client *client,
struct ht16k33_keypad *keypad)
{
@ -479,9 +579,56 @@ static int ht16k33_fbdev_probe(struct device *dev, struct ht16k33_priv *priv,
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;
@ -496,6 +643,9 @@ static int ht16k33_probe(struct i2c_client *client)
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);
@ -520,8 +670,19 @@ static int ht16k33_probe(struct i2c_client *client)
return err;
}
/* Frame Buffer Display */
return ht16k33_fbdev_probe(dev, priv, dft_brightness);
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 int ht16k33_remove(struct i2c_client *client)
@ -530,9 +691,21 @@ static int ht16k33_remove(struct i2c_client *client)
struct ht16k33_fbdev *fbdev = &priv->fbdev;
cancel_delayed_work_sync(&priv->work);
unregister_framebuffer(fbdev->info);
framebuffer_release(fbdev->info);
free_page((unsigned long) fbdev->buffer);
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;
}
return 0;
}
@ -544,7 +717,16 @@ static const struct i2c_device_id ht16k33_i2c_match[] = {
MODULE_DEVICE_TABLE(i2c, ht16k33_i2c_match);
static const struct of_device_id ht16k33_of_match[] = {
{ .compatible = "holtek,ht16k33", },
{
/* 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);