kernel-aes67/drivers/auxdisplay/seg-led-gpio.c

112 lines
2.9 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Driver for a 7-segment LED display
*
* The decimal point LED present on some devices is currently not
* supported.
*
* Copyright (C) Allied Telesis Labs
*/
#include <linux/bitmap.h>
#include <linux/container_of.h>
#include <linux/errno.h>
#include <linux/gpio/consumer.h>
#include <linux/map_to_7segment.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/types.h>
#include <linux/workqueue.h>
#include "line-display.h"
struct seg_led_priv {
struct linedisp linedisp;
struct delayed_work work;
struct gpio_descs *segment_gpios;
};
static void seg_led_update(struct work_struct *work)
{
struct seg_led_priv *priv = container_of(work, struct seg_led_priv, work.work);
struct linedisp *linedisp = &priv->linedisp;
struct linedisp_map *map = linedisp->map;
DECLARE_BITMAP(values, 8) = { };
bitmap_set_value8(values, map_to_seg7(&map->map.seg7, linedisp->buf[0]), 0);
gpiod_set_array_value_cansleep(priv->segment_gpios->ndescs, priv->segment_gpios->desc,
priv->segment_gpios->info, values);
}
static int seg_led_linedisp_get_map_type(struct linedisp *linedisp)
{
struct seg_led_priv *priv = container_of(linedisp, struct seg_led_priv, linedisp);
INIT_DELAYED_WORK(&priv->work, seg_led_update);
return LINEDISP_MAP_SEG7;
}
static void seg_led_linedisp_update(struct linedisp *linedisp)
{
struct seg_led_priv *priv = container_of(linedisp, struct seg_led_priv, linedisp);
schedule_delayed_work(&priv->work, 0);
}
static const struct linedisp_ops seg_led_linedisp_ops = {
.get_map_type = seg_led_linedisp_get_map_type,
.update = seg_led_linedisp_update,
};
static int seg_led_probe(struct platform_device *pdev)
{
struct seg_led_priv *priv;
struct device *dev = &pdev->dev;
priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
platform_set_drvdata(pdev, priv);
priv->segment_gpios = devm_gpiod_get_array(dev, "segment", GPIOD_OUT_LOW);
if (IS_ERR(priv->segment_gpios))
return PTR_ERR(priv->segment_gpios);
if (priv->segment_gpios->ndescs < 7 || priv->segment_gpios->ndescs > 8)
return -EINVAL;
return linedisp_register(&priv->linedisp, dev, 1, &seg_led_linedisp_ops);
}
static void seg_led_remove(struct platform_device *pdev)
{
struct seg_led_priv *priv = platform_get_drvdata(pdev);
cancel_delayed_work_sync(&priv->work);
linedisp_unregister(&priv->linedisp);
}
static const struct of_device_id seg_led_of_match[] = {
{ .compatible = "gpio-7-segment"},
{}
};
MODULE_DEVICE_TABLE(of, seg_led_of_match);
static struct platform_driver seg_led_driver = {
.probe = seg_led_probe,
.remove_new = seg_led_remove,
.driver = {
.name = "seg-led-gpio",
.of_match_table = seg_led_of_match,
},
};
module_platform_driver(seg_led_driver);
MODULE_AUTHOR("Chris Packham <chris.packham@alliedtelesis.co.nz>");
MODULE_DESCRIPTION("7 segment LED driver");
MODULE_LICENSE("GPL");
MODULE_IMPORT_NS(LINEDISP);