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/mod_devicetable.h>
18 #include <linux/module.h>
19 #include <linux/pm.h>
20 #include <linux/regmap.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 return regmap_assign_bits(priv->regmap, REG_CONFIGURATION, REG_CONFIGURATION_S_BIT, enable);
90 }
91
max6959_power_off(void * priv)92 static void max6959_power_off(void *priv)
93 {
94 max6959_enable(priv, false);
95 }
96
max6959_power_on(struct max6959_priv * priv)97 static int max6959_power_on(struct max6959_priv *priv)
98 {
99 struct device *dev = regmap_get_device(priv->regmap);
100 int ret;
101
102 ret = max6959_enable(priv, true);
103 if (ret)
104 return ret;
105
106 return devm_add_action_or_reset(dev, max6959_power_off, priv);
107 }
108
109 static const struct regmap_config max6959_regmap_config = {
110 .reg_bits = 8,
111 .val_bits = 8,
112
113 .max_register = REG_MAX,
114 .cache_type = REGCACHE_MAPLE,
115 };
116
max6959_i2c_probe(struct i2c_client * client)117 static int max6959_i2c_probe(struct i2c_client *client)
118 {
119 struct device *dev = &client->dev;
120 struct max6959_priv *priv;
121 int ret;
122
123 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
124 if (!priv)
125 return -ENOMEM;
126
127 priv->regmap = devm_regmap_init_i2c(client, &max6959_regmap_config);
128 if (IS_ERR(priv->regmap))
129 return PTR_ERR(priv->regmap);
130
131 ret = max6959_power_on(priv);
132 if (ret)
133 return ret;
134
135 ret = linedisp_register(&priv->linedisp, dev, 4, &max6959_linedisp_ops);
136 if (ret)
137 return ret;
138
139 i2c_set_clientdata(client, priv);
140
141 return 0;
142 }
143
max6959_i2c_remove(struct i2c_client * client)144 static void max6959_i2c_remove(struct i2c_client *client)
145 {
146 struct max6959_priv *priv = i2c_get_clientdata(client);
147
148 cancel_delayed_work_sync(&priv->work);
149 linedisp_unregister(&priv->linedisp);
150 }
151
max6959_suspend(struct device * dev)152 static int max6959_suspend(struct device *dev)
153 {
154 return max6959_enable(dev_get_drvdata(dev), false);
155 }
156
max6959_resume(struct device * dev)157 static int max6959_resume(struct device *dev)
158 {
159 return max6959_enable(dev_get_drvdata(dev), true);
160 }
161
162 static DEFINE_SIMPLE_DEV_PM_OPS(max6959_pm_ops, max6959_suspend, max6959_resume);
163
164 static const struct i2c_device_id max6959_i2c_id[] = {
165 { "max6959" },
166 { }
167 };
168 MODULE_DEVICE_TABLE(i2c, max6959_i2c_id);
169
170 static const struct of_device_id max6959_of_table[] = {
171 { .compatible = "maxim,max6959" },
172 { }
173 };
174 MODULE_DEVICE_TABLE(of, max6959_of_table);
175
176 static struct i2c_driver max6959_i2c_driver = {
177 .driver = {
178 .name = "max6959",
179 .pm = pm_sleep_ptr(&max6959_pm_ops),
180 .of_match_table = max6959_of_table,
181 },
182 .probe = max6959_i2c_probe,
183 .remove = max6959_i2c_remove,
184 .id_table = max6959_i2c_id,
185 };
186 module_i2c_driver(max6959_i2c_driver);
187
188 MODULE_DESCRIPTION("MAX6958/6959 7-segment LED controller");
189 MODULE_AUTHOR("Andy Shevchenko <andriy.shevchenko@linux.intel.com>");
190 MODULE_LICENSE("GPL");
191 MODULE_IMPORT_NS("LINEDISP");
192