Commit a0428724 authored by Geert Uytterhoeven's avatar Geert Uytterhoeven Committed by Miguel Ojeda
Browse files

auxdisplay: ht16k33: Add support for segment displays 



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: default avatarGeert Uytterhoeven <geert@linux-m68k.org>
Acked-by: default avatarRobin van der Gracht <robin@protonic.nl>
Signed-off-by: default avatarMiguel Ojeda <ojeda@kernel.org>
parent fcbb3c35

drivers/auxdisplay/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -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.

drivers/auxdisplay/ht16k33.c

+189 −7
Original line number Diff line number Diff line
@@ -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;

	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;

	}



	switch (priv->type) {

	case DISP_MATRIX:

		/* Frame Buffer Display */

	return ht16k33_fbdev_probe(dev, priv, dft_brightness);

		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);



	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);