1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * Driver for a 7-segment LED display |
4 | * |
5 | * The decimal point LED present on some devices is currently not |
6 | * supported. |
7 | * |
8 | * Copyright (C) Allied Telesis Labs |
9 | */ |
10 | |
11 | #include <linux/bitmap.h> |
12 | #include <linux/container_of.h> |
13 | #include <linux/errno.h> |
14 | #include <linux/gpio/consumer.h> |
15 | #include <linux/map_to_7segment.h> |
16 | #include <linux/mod_devicetable.h> |
17 | #include <linux/module.h> |
18 | #include <linux/platform_device.h> |
19 | #include <linux/types.h> |
20 | #include <linux/workqueue.h> |
21 | |
22 | #include "line-display.h" |
23 | |
24 | struct seg_led_priv { |
25 | struct linedisp linedisp; |
26 | struct delayed_work work; |
27 | struct gpio_descs *segment_gpios; |
28 | }; |
29 | |
30 | static void seg_led_update(struct work_struct *work) |
31 | { |
32 | struct seg_led_priv *priv = container_of(work, struct seg_led_priv, work.work); |
33 | struct linedisp *linedisp = &priv->linedisp; |
34 | struct linedisp_map *map = linedisp->map; |
35 | DECLARE_BITMAP(values, 8) = { }; |
36 | |
37 | bitmap_set_value8(map: values, value: map_to_seg7(map: &map->map.seg7, c: linedisp->buf[0]), start: 0); |
38 | |
39 | gpiod_set_array_value_cansleep(array_size: priv->segment_gpios->ndescs, desc_array: priv->segment_gpios->desc, |
40 | array_info: priv->segment_gpios->info, value_bitmap: values); |
41 | } |
42 | |
43 | static int seg_led_linedisp_get_map_type(struct linedisp *linedisp) |
44 | { |
45 | struct seg_led_priv *priv = container_of(linedisp, struct seg_led_priv, linedisp); |
46 | |
47 | INIT_DELAYED_WORK(&priv->work, seg_led_update); |
48 | return LINEDISP_MAP_SEG7; |
49 | } |
50 | |
51 | static void seg_led_linedisp_update(struct linedisp *linedisp) |
52 | { |
53 | struct seg_led_priv *priv = container_of(linedisp, struct seg_led_priv, linedisp); |
54 | |
55 | schedule_delayed_work(dwork: &priv->work, delay: 0); |
56 | } |
57 | |
58 | static const struct linedisp_ops seg_led_linedisp_ops = { |
59 | .get_map_type = seg_led_linedisp_get_map_type, |
60 | .update = seg_led_linedisp_update, |
61 | }; |
62 | |
63 | static int seg_led_probe(struct platform_device *pdev) |
64 | { |
65 | struct seg_led_priv *priv; |
66 | struct device *dev = &pdev->dev; |
67 | |
68 | priv = devm_kzalloc(dev, size: sizeof(*priv), GFP_KERNEL); |
69 | if (!priv) |
70 | return -ENOMEM; |
71 | |
72 | platform_set_drvdata(pdev, data: priv); |
73 | |
74 | priv->segment_gpios = devm_gpiod_get_array(dev, con_id: "segment" , flags: GPIOD_OUT_LOW); |
75 | if (IS_ERR(ptr: priv->segment_gpios)) |
76 | return PTR_ERR(ptr: priv->segment_gpios); |
77 | |
78 | if (priv->segment_gpios->ndescs < 7 || priv->segment_gpios->ndescs > 8) |
79 | return -EINVAL; |
80 | |
81 | return linedisp_register(linedisp: &priv->linedisp, parent: dev, num_chars: 1, ops: &seg_led_linedisp_ops); |
82 | } |
83 | |
84 | static int seg_led_remove(struct platform_device *pdev) |
85 | { |
86 | struct seg_led_priv *priv = platform_get_drvdata(pdev); |
87 | |
88 | cancel_delayed_work_sync(dwork: &priv->work); |
89 | linedisp_unregister(linedisp: &priv->linedisp); |
90 | |
91 | return 0; |
92 | } |
93 | |
94 | static const struct of_device_id seg_led_of_match[] = { |
95 | { .compatible = "gpio-7-segment" }, |
96 | {} |
97 | }; |
98 | MODULE_DEVICE_TABLE(of, seg_led_of_match); |
99 | |
100 | static struct platform_driver seg_led_driver = { |
101 | .probe = seg_led_probe, |
102 | .remove = seg_led_remove, |
103 | .driver = { |
104 | .name = "seg-led-gpio" , |
105 | .of_match_table = seg_led_of_match, |
106 | }, |
107 | }; |
108 | module_platform_driver(seg_led_driver); |
109 | |
110 | MODULE_AUTHOR("Chris Packham <chris.packham@alliedtelesis.co.nz>" ); |
111 | MODULE_DESCRIPTION("7 segment LED driver" ); |
112 | MODULE_LICENSE("GPL" ); |
113 | MODULE_IMPORT_NS(LINEDISP); |
114 | |