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
44 struct max6959_priv {
45 struct linedisp linedisp;
46 struct delayed_work work;
47 struct regmap *regmap;
48 };
49
max6959_disp_update(struct work_struct * work)50 static 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(priv->regmap, REG_DIGIT(0), buf, ARRAY_SIZE(buf));
65 }
66
max6959_linedisp_get_map_type(struct linedisp * linedisp)67 static 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
max6959_linedisp_update(struct linedisp * linedisp)75 static 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(&priv->work, 0);
80 }
81
82 static const struct linedisp_ops max6959_linedisp_ops = {
83 .get_map_type = max6959_linedisp_get_map_type,
84 .update = max6959_linedisp_update,
85 };
86
max6959_enable(struct max6959_priv * priv,bool enable)87 static 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(priv->regmap, REG_CONFIGURATION, mask, value);
93 }
94
max6959_power_off(void * priv)95 static void max6959_power_off(void *priv)
96 {
97 max6959_enable(priv, false);
98 }
99
max6959_power_on(struct max6959_priv * priv)100 static int max6959_power_on(struct max6959_priv *priv)
101 {
102 struct device *dev = regmap_get_device(priv->regmap);
103 int ret;
104
105 ret = max6959_enable(priv, true);
106 if (ret)
107 return ret;
108
109 return devm_add_action_or_reset(dev, max6959_power_off, priv);
110 }
111
112 static 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
max6959_i2c_probe(struct i2c_client * client)120 static 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, 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(priv->regmap))
132 return PTR_ERR(priv->regmap);
133
134 ret = max6959_power_on(priv);
135 if (ret)
136 return ret;
137
138 ret = linedisp_register(&priv->linedisp, dev, 4, &max6959_linedisp_ops);
139 if (ret)
140 return ret;
141
142 i2c_set_clientdata(client, priv);
143
144 return 0;
145 }
146
max6959_i2c_remove(struct i2c_client * client)147 static void max6959_i2c_remove(struct i2c_client *client)
148 {
149 struct max6959_priv *priv = i2c_get_clientdata(client);
150
151 cancel_delayed_work_sync(&priv->work);
152 linedisp_unregister(&priv->linedisp);
153 }
154
max6959_suspend(struct device * dev)155 static int max6959_suspend(struct device *dev)
156 {
157 return max6959_enable(dev_get_drvdata(dev), false);
158 }
159
max6959_resume(struct device * dev)160 static int max6959_resume(struct device *dev)
161 {
162 return max6959_enable(dev_get_drvdata(dev), true);
163 }
164
165 static DEFINE_SIMPLE_DEV_PM_OPS(max6959_pm_ops, max6959_suspend, max6959_resume);
166
167 static const struct i2c_device_id max6959_i2c_id[] = {
168 { "max6959" },
169 { }
170 };
171 MODULE_DEVICE_TABLE(i2c, max6959_i2c_id);
172
173 static const struct of_device_id max6959_of_table[] = {
174 { .compatible = "maxim,max6959" },
175 { }
176 };
177 MODULE_DEVICE_TABLE(of, max6959_of_table);
178
179 static 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 };
189 module_i2c_driver(max6959_i2c_driver);
190
191 MODULE_DESCRIPTION("MAX6958/6959 7-segment LED controller");
192 MODULE_AUTHOR("Andy Shevchenko <andriy.shevchenko@linux.intel.com>");
193 MODULE_LICENSE("GPL");
194 MODULE_IMPORT_NS(LINEDISP);
195