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 | |
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(map: priv->regmap, REG_DIGIT(0), val: buf, ARRAY_SIZE(buf)); |
65 | } |
66 | |
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 | |
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(dwork: &priv->work, delay: 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 | |
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(map: priv->regmap, REG_CONFIGURATION, mask, val: value); |
93 | } |
94 | |
95 | static void max6959_power_off(void *priv) |
96 | { |
97 | max6959_enable(priv, enable: false); |
98 | } |
99 | |
100 | static 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 | |
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 | |
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, 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 | |
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(dwork: &priv->work); |
152 | linedisp_unregister(linedisp: &priv->linedisp); |
153 | } |
154 | |
155 | static int max6959_suspend(struct device *dev) |
156 | { |
157 | return max6959_enable(priv: dev_get_drvdata(dev), enable: false); |
158 | } |
159 | |
160 | static int max6959_resume(struct device *dev) |
161 | { |
162 | return max6959_enable(priv: dev_get_drvdata(dev), enable: 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 | |