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c352a04107
The .remove() callback for a platform driver returns an int which makes many driver authors wrongly assume it's possible to do error handling by returning an error code. However the value returned is ignored (apart from emitting a warning) and this typically results in resource leaks. To improve here there is a quest to make the remove callback return void. In the first step of this quest all drivers are converted to .remove_new(), which already returns void. Eventually after all drivers are converted, .remove_new() will be renamed to .remove(). Trivially convert this driver from always returning zero in the remove callback to the void returning variant. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
112 lines
2.9 KiB
C
112 lines
2.9 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Driver for a 7-segment LED display
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*
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* The decimal point LED present on some devices is currently not
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* supported.
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*
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* Copyright (C) Allied Telesis Labs
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*/
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#include <linux/bitmap.h>
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#include <linux/container_of.h>
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#include <linux/errno.h>
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#include <linux/gpio/consumer.h>
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#include <linux/map_to_7segment.h>
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#include <linux/mod_devicetable.h>
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#include <linux/module.h>
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#include <linux/platform_device.h>
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#include <linux/types.h>
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#include <linux/workqueue.h>
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#include "line-display.h"
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struct seg_led_priv {
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struct linedisp linedisp;
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struct delayed_work work;
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struct gpio_descs *segment_gpios;
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};
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static void seg_led_update(struct work_struct *work)
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{
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struct seg_led_priv *priv = container_of(work, struct seg_led_priv, work.work);
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struct linedisp *linedisp = &priv->linedisp;
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struct linedisp_map *map = linedisp->map;
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DECLARE_BITMAP(values, 8) = { };
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bitmap_set_value8(values, map_to_seg7(&map->map.seg7, linedisp->buf[0]), 0);
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gpiod_set_array_value_cansleep(priv->segment_gpios->ndescs, priv->segment_gpios->desc,
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priv->segment_gpios->info, values);
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}
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static int seg_led_linedisp_get_map_type(struct linedisp *linedisp)
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{
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struct seg_led_priv *priv = container_of(linedisp, struct seg_led_priv, linedisp);
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INIT_DELAYED_WORK(&priv->work, seg_led_update);
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return LINEDISP_MAP_SEG7;
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}
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static void seg_led_linedisp_update(struct linedisp *linedisp)
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{
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struct seg_led_priv *priv = container_of(linedisp, struct seg_led_priv, linedisp);
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schedule_delayed_work(&priv->work, 0);
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}
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static const struct linedisp_ops seg_led_linedisp_ops = {
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.get_map_type = seg_led_linedisp_get_map_type,
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.update = seg_led_linedisp_update,
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};
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static int seg_led_probe(struct platform_device *pdev)
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{
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struct seg_led_priv *priv;
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struct device *dev = &pdev->dev;
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priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
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if (!priv)
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return -ENOMEM;
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platform_set_drvdata(pdev, priv);
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priv->segment_gpios = devm_gpiod_get_array(dev, "segment", GPIOD_OUT_LOW);
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if (IS_ERR(priv->segment_gpios))
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return PTR_ERR(priv->segment_gpios);
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if (priv->segment_gpios->ndescs < 7 || priv->segment_gpios->ndescs > 8)
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return -EINVAL;
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return linedisp_register(&priv->linedisp, dev, 1, &seg_led_linedisp_ops);
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}
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static void seg_led_remove(struct platform_device *pdev)
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{
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struct seg_led_priv *priv = platform_get_drvdata(pdev);
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cancel_delayed_work_sync(&priv->work);
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linedisp_unregister(&priv->linedisp);
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}
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static const struct of_device_id seg_led_of_match[] = {
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{ .compatible = "gpio-7-segment"},
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{}
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};
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MODULE_DEVICE_TABLE(of, seg_led_of_match);
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static struct platform_driver seg_led_driver = {
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.probe = seg_led_probe,
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.remove_new = seg_led_remove,
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.driver = {
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.name = "seg-led-gpio",
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.of_match_table = seg_led_of_match,
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},
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};
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module_platform_driver(seg_led_driver);
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MODULE_AUTHOR("Chris Packham <chris.packham@alliedtelesis.co.nz>");
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MODULE_DESCRIPTION("7 segment LED driver");
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MODULE_LICENSE("GPL");
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MODULE_IMPORT_NS(LINEDISP);
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