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