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
 44struct max6959_priv {
 45	struct linedisp linedisp;
 46	struct delayed_work work;
 47	struct regmap *regmap;
 48};
 49
 50static 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
 67static 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
 75static 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
 82static const struct linedisp_ops max6959_linedisp_ops = {
 83	.get_map_type = max6959_linedisp_get_map_type,
 84	.update = max6959_linedisp_update,
 85};
 86
 87static 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
 95static void max6959_power_off(void *priv)
 96{
 97	max6959_enable(priv, false);
 98}
 99
100static 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
112static 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
120static 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
147static 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
155static int max6959_suspend(struct device *dev)
156{
157	return max6959_enable(dev_get_drvdata(dev), false);
158}
159
160static int max6959_resume(struct device *dev)
161{
162	return max6959_enable(dev_get_drvdata(dev), true);
163}
164
165static DEFINE_SIMPLE_DEV_PM_OPS(max6959_pm_ops, max6959_suspend, max6959_resume);
166
167static const struct i2c_device_id max6959_i2c_id[] = {
168	{ "max6959" },
169	{ }
170};
171MODULE_DEVICE_TABLE(i2c, max6959_i2c_id);
172
173static const struct of_device_id max6959_of_table[] = {
174	{ .compatible = "maxim,max6959" },
175	{ }
176};
177MODULE_DEVICE_TABLE(of, max6959_of_table);
178
179static 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};
189module_i2c_driver(max6959_i2c_driver);
190
191MODULE_DESCRIPTION("MAX6958/6959 7-segment LED controller");
192MODULE_AUTHOR("Andy Shevchenko <andriy.shevchenko@linux.intel.com>");
193MODULE_LICENSE("GPL");
194MODULE_IMPORT_NS("LINEDISP");