1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Maxim MAX77714 Core Driver
4 *
5 * Copyright (C) 2022 Luca Ceresoli
6 * Author: Luca Ceresoli <luca.ceresoli@bootlin.com>
7 */
8
9#include <linux/i2c.h>
10#include <linux/interrupt.h>
11#include <linux/mfd/core.h>
12#include <linux/mfd/max77714.h>
13#include <linux/module.h>
14#include <linux/of.h>
15#include <linux/regmap.h>
16
17static const struct mfd_cell max77714_cells[] = {
18	{ .name = "max77714-watchdog" },
19	{ .name = "max77714-rtc" },
20};
21
22static const struct regmap_range max77714_readable_ranges[] = {
23	regmap_reg_range(MAX77714_INT_TOP,     MAX77714_INT_TOP),
24	regmap_reg_range(MAX77714_INT_TOPM,    MAX77714_INT_TOPM),
25	regmap_reg_range(MAX77714_32K_STATUS,  MAX77714_32K_CONFIG),
26	regmap_reg_range(MAX77714_CNFG_GLBL2,  MAX77714_CNFG2_ONOFF),
27};
28
29static const struct regmap_range max77714_writable_ranges[] = {
30	regmap_reg_range(MAX77714_INT_TOPM,    MAX77714_INT_TOPM),
31	regmap_reg_range(MAX77714_32K_CONFIG,  MAX77714_32K_CONFIG),
32	regmap_reg_range(MAX77714_CNFG_GLBL2,  MAX77714_CNFG2_ONOFF),
33};
34
35static const struct regmap_access_table max77714_readable_table = {
36	.yes_ranges = max77714_readable_ranges,
37	.n_yes_ranges = ARRAY_SIZE(max77714_readable_ranges),
38};
39
40static const struct regmap_access_table max77714_writable_table = {
41	.yes_ranges = max77714_writable_ranges,
42	.n_yes_ranges = ARRAY_SIZE(max77714_writable_ranges),
43};
44
45static const struct regmap_config max77714_regmap_config = {
46	.reg_bits = 8,
47	.val_bits = 8,
48	.max_register = MAX77714_CNFG2_ONOFF,
49	.rd_table = &max77714_readable_table,
50	.wr_table = &max77714_writable_table,
51};
52
53static const struct regmap_irq max77714_top_irqs[] = {
54	REGMAP_IRQ_REG(MAX77714_IRQ_TOP_ONOFF,   0, MAX77714_INT_TOP_ONOFF),
55	REGMAP_IRQ_REG(MAX77714_IRQ_TOP_RTC,     0, MAX77714_INT_TOP_RTC),
56	REGMAP_IRQ_REG(MAX77714_IRQ_TOP_GPIO,    0, MAX77714_INT_TOP_GPIO),
57	REGMAP_IRQ_REG(MAX77714_IRQ_TOP_LDO,     0, MAX77714_INT_TOP_LDO),
58	REGMAP_IRQ_REG(MAX77714_IRQ_TOP_SD,      0, MAX77714_INT_TOP_SD),
59	REGMAP_IRQ_REG(MAX77714_IRQ_TOP_GLBL,    0, MAX77714_INT_TOP_GLBL),
60};
61
62static const struct regmap_irq_chip max77714_irq_chip = {
63	.name			= "max77714-pmic",
64	.status_base		= MAX77714_INT_TOP,
65	.mask_base		= MAX77714_INT_TOPM,
66	.num_regs		= 1,
67	.irqs			= max77714_top_irqs,
68	.num_irqs		= ARRAY_SIZE(max77714_top_irqs),
69};
70
71/*
72 * MAX77714 initially uses the internal, low precision oscillator. Enable
73 * the external oscillator by setting the XOSC_RETRY bit. If the external
74 * oscillator is not OK (probably not installed) this has no effect.
75 */
76static int max77714_setup_xosc(struct device *dev, struct regmap *regmap)
77{
78	/* Internal Crystal Load Capacitance, indexed by value of 32KLOAD bits */
79	static const unsigned int load_cap[4] = {0, 10, 12, 22}; /* pF */
80	unsigned int load_cap_idx;
81	unsigned int status;
82	int err;
83
84	err = regmap_update_bits(regmap, MAX77714_32K_CONFIG,
85				 MAX77714_32K_CONFIG_XOSC_RETRY,
86				 MAX77714_32K_CONFIG_XOSC_RETRY);
87	if (err)
88		return dev_err_probe(dev, err, "Failed to configure the external oscillator\n");
89
90	err = regmap_read(regmap, MAX77714_32K_STATUS, &status);
91	if (err)
92		return dev_err_probe(dev, err, "Failed to read external oscillator status\n");
93
94	load_cap_idx = (status >> MAX77714_32K_STATUS_32KLOAD_SHF)
95		& MAX77714_32K_STATUS_32KLOAD_MSK;
96
97	dev_info(dev, "Using %s oscillator, %d pF load cap\n",
98		 status & MAX77714_32K_STATUS_32KSOURCE ? "internal" : "external",
99		 load_cap[load_cap_idx]);
100
101	return 0;
102}
103
104static int max77714_probe(struct i2c_client *client)
105{
106	struct device *dev = &client->dev;
107	struct regmap *regmap;
108	struct regmap_irq_chip_data *irq_data;
109	int err;
110
111	regmap = devm_regmap_init_i2c(client, &max77714_regmap_config);
112	if (IS_ERR(regmap))
113		return dev_err_probe(dev, PTR_ERR(regmap),
114				     "Failed to initialise regmap\n");
115
116	err = max77714_setup_xosc(dev, regmap);
117	if (err)
118		return err;
119
120	err = devm_regmap_add_irq_chip(dev, regmap, client->irq,
121				       IRQF_ONESHOT | IRQF_SHARED, 0,
122				       &max77714_irq_chip, &irq_data);
123	if (err)
124		return dev_err_probe(dev, err, "Failed to add PMIC IRQ chip\n");
125
126	err =  devm_mfd_add_devices(dev, PLATFORM_DEVID_NONE,
127				    max77714_cells, ARRAY_SIZE(max77714_cells),
128				    NULL, 0, NULL);
129	if (err)
130		return dev_err_probe(dev, err, "Failed to register child devices\n");
131
132	return 0;
133}
134
135static const struct of_device_id max77714_dt_match[] = {
136	{ .compatible = "maxim,max77714" },
137	{},
138};
139MODULE_DEVICE_TABLE(of, max77714_dt_match);
140
141static struct i2c_driver max77714_driver = {
142	.driver = {
143		.name = "max77714",
144		.of_match_table = max77714_dt_match,
145	},
146	.probe = max77714_probe,
147};
148module_i2c_driver(max77714_driver);
149
150MODULE_DESCRIPTION("Maxim MAX77714 MFD core driver");
151MODULE_AUTHOR("Luca Ceresoli <luca.ceresoli@bootlin.com>");
152MODULE_LICENSE("GPL");
153