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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Maxim MAX7360 Core Driver
4 *
5 * Copyright 2025 Bootlin
6 *
7 * Authors:
8 * Kamel Bouhara <[email protected]>
9 * Mathieu Dubois-Briand <[email protected]>
10 */
11
12#include <linux/array_size.h>
13#include <linux/bits.h>
14#include <linux/delay.h>
15#include <linux/device/devres.h>
16#include <linux/dev_printk.h>
17#include <linux/err.h>
18#include <linux/i2c.h>
19#include <linux/interrupt.h>
20#include <linux/mfd/core.h>
21#include <linux/mfd/max7360.h>
22#include <linux/module.h>
23#include <linux/regmap.h>
24#include <linux/types.h>
25
26static const struct mfd_cell max7360_cells[] = {
27 { .name = "max7360-pinctrl" },
28 { .name = "max7360-pwm" },
29 { .name = "max7360-keypad" },
30 { .name = "max7360-rotary" },
31 {
32 .name = "max7360-gpo",
33 .of_compatible = "maxim,max7360-gpo",
34 },
35 {
36 .name = "max7360-gpio",
37 .of_compatible = "maxim,max7360-gpio",
38 },
39};
40
41static const struct regmap_range max7360_volatile_ranges[] = {
42 regmap_reg_range(MAX7360_REG_KEYFIFO, MAX7360_REG_KEYFIFO),
43 regmap_reg_range(MAX7360_REG_I2C_TIMEOUT, MAX7360_REG_RTR_CNT),
44};
45
46static const struct regmap_access_table max7360_volatile_table = {
47 .yes_ranges = max7360_volatile_ranges,
48 .n_yes_ranges = ARRAY_SIZE(max7360_volatile_ranges),
49};
50
51static const struct regmap_config max7360_regmap_config = {
52 .reg_bits = 8,
53 .val_bits = 8,
54 .max_register = MAX7360_REG_PWMCFG(MAX7360_PORT_PWM_COUNT - 1),
55 .volatile_table = &max7360_volatile_table,
56 .cache_type = REGCACHE_MAPLE,
57};
58
59static int max7360_mask_irqs(struct regmap *regmap)
60{
61 struct device *dev = regmap_get_device(regmap);
62 unsigned int val;
63 int ret;
64
65 /*
66 * GPIO/PWM interrupts are not masked on reset: as the MAX7360 "INTI"
67 * interrupt line is shared between GPIOs and rotary encoder, this could
68 * result in repeated spurious interrupts on the rotary encoder driver
69 * if the GPIO driver is not loaded. Mask them now to avoid this
70 * situation.
71 */
72 for (unsigned int i = 0; i < MAX7360_PORT_PWM_COUNT; i++) {
73 ret = regmap_write_bits(regmap, MAX7360_REG_PWMCFG(i),
74 MAX7360_PORT_CFG_INTERRUPT_MASK,
75 MAX7360_PORT_CFG_INTERRUPT_MASK);
76 if (ret)
77 return dev_err_probe(dev, ret,
78 "Failed to write MAX7360 port configuration\n");
79 }
80
81 /* Read GPIO in register, to ACK any pending IRQ. */
82 ret = regmap_read(regmap, MAX7360_REG_GPIOIN, &val);
83 if (ret)
84 return dev_err_probe(dev, ret, "Failed to read GPIO values\n");
85
86 return 0;
87}
88
89static int max7360_reset(struct regmap *regmap)
90{
91 struct device *dev = regmap_get_device(regmap);
92 int ret;
93
94 ret = regmap_write(regmap, MAX7360_REG_GPIOCFG, MAX7360_GPIO_CFG_GPIO_RST);
95 if (ret) {
96 dev_err(dev, "Failed to reset GPIO configuration: %x\n", ret);
97 return ret;
98 }
99
100 ret = regcache_drop_region(regmap, MAX7360_REG_GPIOCFG, MAX7360_REG_GPIO_LAST);
101 if (ret) {
102 dev_err(dev, "Failed to drop regmap cache: %x\n", ret);
103 return ret;
104 }
105
106 ret = regmap_write(regmap, MAX7360_REG_SLEEP, 0);
107 if (ret) {
108 dev_err(dev, "Failed to reset autosleep configuration: %x\n", ret);
109 return ret;
110 }
111
112 ret = regmap_write(regmap, MAX7360_REG_DEBOUNCE, 0);
113 if (ret)
114 dev_err(dev, "Failed to reset GPO port count: %x\n", ret);
115
116 return ret;
117}
118
119static int max7360_probe(struct i2c_client *client)
120{
121 struct device *dev = &client->dev;
122 struct regmap *regmap;
123 int ret;
124
125 regmap = devm_regmap_init_i2c(client, &max7360_regmap_config);
126 if (IS_ERR(regmap))
127 return dev_err_probe(dev, PTR_ERR(regmap), "Failed to initialise regmap\n");
128
129 ret = max7360_reset(regmap);
130 if (ret)
131 return dev_err_probe(dev, ret, "Failed to reset device\n");
132
133 /* Get the device out of shutdown mode. */
134 ret = regmap_write_bits(regmap, MAX7360_REG_GPIOCFG,
135 MAX7360_GPIO_CFG_GPIO_EN,
136 MAX7360_GPIO_CFG_GPIO_EN);
137 if (ret)
138 return dev_err_probe(dev, ret, "Failed to enable GPIO and PWM module\n");
139
140 ret = max7360_mask_irqs(regmap);
141 if (ret)
142 return dev_err_probe(dev, ret, "Could not mask interrupts\n");
143
144 ret = devm_mfd_add_devices(dev, PLATFORM_DEVID_NONE,
145 max7360_cells, ARRAY_SIZE(max7360_cells),
146 NULL, 0, NULL);
147 if (ret)
148 return dev_err_probe(dev, ret, "Failed to register child devices\n");
149
150 return 0;
151}
152
153static const struct of_device_id max7360_dt_match[] = {
154 { .compatible = "maxim,max7360" },
155 {}
156};
157MODULE_DEVICE_TABLE(of, max7360_dt_match);
158
159static struct i2c_driver max7360_driver = {
160 .driver = {
161 .name = "max7360",
162 .of_match_table = max7360_dt_match,
163 },
164 .probe = max7360_probe,
165};
166module_i2c_driver(max7360_driver);
167
168MODULE_DESCRIPTION("Maxim MAX7360 I2C IO Expander core driver");
169MODULE_AUTHOR("Kamel Bouhara <[email protected]>");
170MODULE_LICENSE("GPL");