drivers/auxdisplay/max6959.c

   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(priv->regmap, REG_DIGIT(0), 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(&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
  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
  95 static void max6959_power_off(void *priv)
  96 {
  97         max6959_enable(priv, false);
  98 }
  99
 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
 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
 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
 155 static int max6959_suspend(struct device *dev)
 156 {
 157         return max6959_enable(dev_get_drvdata(dev), false);
 158 }
 159
 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);