summaryrefslogtreecommitdiffstats
path: root/drivers/auxdisplay/seg-led-gpio.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/auxdisplay/seg-led-gpio.c')
-rw-r--r--drivers/auxdisplay/seg-led-gpio.c111
1 files changed, 111 insertions, 0 deletions
diff --git a/drivers/auxdisplay/seg-led-gpio.c b/drivers/auxdisplay/seg-led-gpio.c
new file mode 100644
index 0000000000..183ab3011c
--- /dev/null
+++ b/drivers/auxdisplay/seg-led-gpio.c
@@ -0,0 +1,111 @@
+// 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);