[PATCH v5 17/19] auxdisplay: ht16k33: Add support for segment displays

From: Geert Uytterhoeven
Date: Wed Aug 11 2021 - 05:59:27 EST

Next message: Michael Tretter: "Re: [PATCH v2] media: vivid: drop CONFIG_FB dependency"
Previous message: Geert Uytterhoeven: "[PATCH v5 12/19] auxdisplay: ht16k33: Convert to simple i2c probe function"
In reply to: Geert Uytterhoeven: "[PATCH v5 12/19] auxdisplay: ht16k33: Convert to simple i2c probe function"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

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@xxxxxxxxxxxxxx>
---
The 7-segment support is based on schematics, and untested on actual
hardware.

v5:
- No changes,

v4:
- No changes,

v3:
- Pass "dev" instead of "client" to ht16k33_seg_probe(),
- Remove unneeded inclusion of <linux/leds.h> and <linux/of_device.h>,

v2:
- Move "select LINEDISP" to this patch,
- Set "err = -EINVAL" in switch() case that cannot happen.
---
drivers/auxdisplay/Kconfig | 1 +
drivers/auxdisplay/ht16k33.c | 196 +++++++++++++++++++++++++++++++++--
2 files changed, 190 insertions(+), 7 deletions(-)

diff --git a/drivers/auxdisplay/Kconfig b/drivers/auxdisplay/Kconfig
index b41fdc5f7bf72a1b..42fc7b155de09dbc 100644
--- a/drivers/auxdisplay/Kconfig
+++ b/drivers/auxdisplay/Kconfig
@@ -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.
diff --git a/drivers/auxdisplay/ht16k33.c b/drivers/auxdisplay/ht16k33.c
index 27ac167dae74bd82..3b555e119e326cec 100644
--- a/drivers/auxdisplay/ht16k33.c
+++ b/drivers/auxdisplay/ht16k33.c
@@ -5,6 +5,7 @@
* Author: Robin van der Gracht <robin@xxxxxxxxxxx>
*
* 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;
@@ -325,6 +380,51 @@ 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)
{
@@ -469,9 +569,56 @@ 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, MAX_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;
@@ -486,6 +633,9 @@ 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);
@@ -510,8 +660,19 @@ 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)
@@ -520,9 +681,21 @@ 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;
}
@@ -534,7 +707,16 @@ 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);
--
2.25.1

Next message: Michael Tretter: "Re: [PATCH v2] media: vivid: drop CONFIG_FB dependency"
Previous message: Geert Uytterhoeven: "[PATCH v5 12/19] auxdisplay: ht16k33: Convert to simple i2c probe function"
In reply to: Geert Uytterhoeven: "[PATCH v5 12/19] auxdisplay: ht16k33: Convert to simple i2c probe function"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]