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
17 static const struct mfd_cell max77714_cells[] = {
18 { .name = "max77714-watchdog" },
19 { .name = "max77714-rtc" },
20 };
21
22 static 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
29 static 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
35 static 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
40 static 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
45 static 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
53 static 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
62 static 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 */
max77714_setup_xosc(struct device * dev,struct regmap * regmap)76 static 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
max77714_probe(struct i2c_client * client)104 static 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
135 static const struct of_device_id max77714_dt_match[] = {
136 { .compatible = "maxim,max77714" },
137 {},
138 };
139 MODULE_DEVICE_TABLE(of, max77714_dt_match);
140
141 static struct i2c_driver max77714_driver = {
142 .driver = {
143 .name = "max77714",
144 .of_match_table = max77714_dt_match,
145 },
146 .probe = max77714_probe,
147 };
148 module_i2c_driver(max77714_driver);
149
150 MODULE_DESCRIPTION("Maxim MAX77714 MFD core driver");
151 MODULE_AUTHOR("Luca Ceresoli <luca.ceresoli@bootlin.com>");
152 MODULE_LICENSE("GPL");
153
