1// SPDX-License-Identifier: GPL-2.0
2/*
3 * MAX6958/6959 7-segment LED display controller
4 * Datasheet:
5 * https://www.analog.com/media/en/technical-documentation/data-sheets/MAX6958-MAX6959.pdf
6 *
7 * Copyright (c) 2024, Intel Corporation.
8 * Author: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
9 */
10#include <linux/array_size.h>
11#include <linux/bitrev.h>
12#include <linux/bits.h>
13#include <linux/container_of.h>
14#include <linux/err.h>
15#include <linux/i2c.h>
16#include <linux/mod_devicetable.h>
17#include <linux/module.h>
18#include <linux/pm.h>
19#include <linux/regmap.h>
20#include <linux/slab.h>
21#include <linux/types.h>
22#include <linux/workqueue.h>
23
24#include <linux/map_to_7segment.h>
25
26#include "line-display.h"
27
28/* Registers */
29#define REG_DECODE_MODE 0x01
30#define REG_INTENSITY 0x02
31#define REG_SCAN_LIMIT 0x03
32#define REG_CONFIGURATION 0x04
33#define REG_CONFIGURATION_S_BIT BIT(0)
34
35#define REG_DIGIT(x) (0x20 + (x))
36#define REG_DIGIT0 0x20
37#define REG_DIGIT1 0x21
38#define REG_DIGIT2 0x22
39#define REG_DIGIT3 0x23
40
41#define REG_SEGMENTS 0x24
42#define REG_MAX REG_SEGMENTS
43
44struct max6959_priv {
45 struct linedisp linedisp;
46 struct delayed_work work;
47 struct regmap *regmap;
48};
49
50static void max6959_disp_update(struct work_struct *work)
51{
52 struct max6959_priv *priv = container_of(work, struct max6959_priv, work.work);
53 struct linedisp *linedisp = &priv->linedisp;
54 struct linedisp_map *map = linedisp->map;
55 char *s = linedisp->buf;
56 u8 buf[4];
57
58 /* Map segments according to datasheet */
59 buf[0] = bitrev8(map_to_seg7(&map->map.seg7, *s++)) >> 1;
60 buf[1] = bitrev8(map_to_seg7(&map->map.seg7, *s++)) >> 1;
61 buf[2] = bitrev8(map_to_seg7(&map->map.seg7, *s++)) >> 1;
62 buf[3] = bitrev8(map_to_seg7(&map->map.seg7, *s++)) >> 1;
63
64 regmap_bulk_write(map: priv->regmap, REG_DIGIT(0), val: buf, ARRAY_SIZE(buf));
65}
66
67static int max6959_linedisp_get_map_type(struct linedisp *linedisp)
68{
69 struct max6959_priv *priv = container_of(linedisp, struct max6959_priv, linedisp);
70
71 INIT_DELAYED_WORK(&priv->work, max6959_disp_update);
72 return LINEDISP_MAP_SEG7;
73}
74
75static void max6959_linedisp_update(struct linedisp *linedisp)
76{
77 struct max6959_priv *priv = container_of(linedisp, struct max6959_priv, linedisp);
78
79 schedule_delayed_work(dwork: &priv->work, delay: 0);
80}
81
82static const struct linedisp_ops max6959_linedisp_ops = {
83 .get_map_type = max6959_linedisp_get_map_type,
84 .update = max6959_linedisp_update,
85};
86
87static int max6959_enable(struct max6959_priv *priv, bool enable)
88{
89 u8 mask = REG_CONFIGURATION_S_BIT;
90 u8 value = enable ? mask : 0;
91
92 return regmap_update_bits(map: priv->regmap, REG_CONFIGURATION, mask, val: value);
93}
94
95static void max6959_power_off(void *priv)
96{
97 max6959_enable(priv, enable: false);
98}
99
100static int max6959_power_on(struct max6959_priv *priv)
101{
102 struct device *dev = regmap_get_device(map: priv->regmap);
103 int ret;
104
105 ret = max6959_enable(priv, enable: true);
106 if (ret)
107 return ret;
108
109 return devm_add_action_or_reset(dev, max6959_power_off, priv);
110}
111
112static const struct regmap_config max6959_regmap_config = {
113 .reg_bits = 8,
114 .val_bits = 8,
115
116 .max_register = REG_MAX,
117 .cache_type = REGCACHE_MAPLE,
118};
119
120static int max6959_i2c_probe(struct i2c_client *client)
121{
122 struct device *dev = &client->dev;
123 struct max6959_priv *priv;
124 int ret;
125
126 priv = devm_kzalloc(dev, size: sizeof(*priv), GFP_KERNEL);
127 if (!priv)
128 return -ENOMEM;
129
130 priv->regmap = devm_regmap_init_i2c(client, &max6959_regmap_config);
131 if (IS_ERR(ptr: priv->regmap))
132 return PTR_ERR(ptr: priv->regmap);
133
134 ret = max6959_power_on(priv);
135 if (ret)
136 return ret;
137
138 ret = linedisp_register(linedisp: &priv->linedisp, parent: dev, num_chars: 4, ops: &max6959_linedisp_ops);
139 if (ret)
140 return ret;
141
142 i2c_set_clientdata(client, data: priv);
143
144 return 0;
145}
146
147static void max6959_i2c_remove(struct i2c_client *client)
148{
149 struct max6959_priv *priv = i2c_get_clientdata(client);
150
151 cancel_delayed_work_sync(dwork: &priv->work);
152 linedisp_unregister(linedisp: &priv->linedisp);
153}
154
155static int max6959_suspend(struct device *dev)
156{
157 return max6959_enable(priv: dev_get_drvdata(dev), enable: false);
158}
159
160static int max6959_resume(struct device *dev)
161{
162 return max6959_enable(priv: dev_get_drvdata(dev), enable: true);
163}
164
165static DEFINE_SIMPLE_DEV_PM_OPS(max6959_pm_ops, max6959_suspend, max6959_resume);
166
167static const struct i2c_device_id max6959_i2c_id[] = {
168 { "max6959" },
169 { }
170};
171MODULE_DEVICE_TABLE(i2c, max6959_i2c_id);
172
173static const struct of_device_id max6959_of_table[] = {
174 { .compatible = "maxim,max6959" },
175 { }
176};
177MODULE_DEVICE_TABLE(of, max6959_of_table);
178
179static struct i2c_driver max6959_i2c_driver = {
180 .driver = {
181 .name = "max6959",
182 .pm = pm_sleep_ptr(&max6959_pm_ops),
183 .of_match_table = max6959_of_table,
184 },
185 .probe = max6959_i2c_probe,
186 .remove = max6959_i2c_remove,
187 .id_table = max6959_i2c_id,
188};
189module_i2c_driver(max6959_i2c_driver);
190
191MODULE_DESCRIPTION("MAX6958/6959 7-segment LED controller");
192MODULE_AUTHOR("Andy Shevchenko <andriy.shevchenko@linux.intel.com>");
193MODULE_LICENSE("GPL");
194MODULE_IMPORT_NS(LINEDISP);
195

source code of linux/drivers/auxdisplay/max6959.c