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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 <kamel.bouhara@bootlin.com>
9 * Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>
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/mod_devicetable.h>
23#include <linux/module.h>
24#include <linux/regmap.h>
25#include <linux/types.h>
26
27static const struct mfd_cell max7360_cells[] = {
28 { .name = "max7360-pinctrl" },
29 { .name = "max7360-pwm" },
30 { .name = "max7360-keypad" },
31 { .name = "max7360-rotary" },
32 {
33 .name = "max7360-gpo",
34 .of_compatible = "maxim,max7360-gpo",
35 },
36 {
37 .name = "max7360-gpio",
38 .of_compatible = "maxim,max7360-gpio",
39 },
40};
41
42static const struct regmap_range max7360_volatile_ranges[] = {
43 regmap_reg_range(MAX7360_REG_KEYFIFO, MAX7360_REG_KEYFIFO),
44 regmap_reg_range(MAX7360_REG_I2C_TIMEOUT, MAX7360_REG_RTR_CNT),
45};
46
47static const struct regmap_access_table max7360_volatile_table = {
48 .yes_ranges = max7360_volatile_ranges,
49 .n_yes_ranges = ARRAY_SIZE(max7360_volatile_ranges),
50};
51
52static const struct regmap_config max7360_regmap_config = {
53 .reg_bits = 8,
54 .val_bits = 8,
55 .max_register = MAX7360_REG_PWMCFG(MAX7360_PORT_PWM_COUNT - 1),
56 .volatile_table = &max7360_volatile_table,
57 .cache_type = REGCACHE_MAPLE,
58};
59
60static int max7360_mask_irqs(struct regmap *regmap)
61{
62 struct device *dev = regmap_get_device(regmap);
63 unsigned int val;
64 int ret;
65
66 /*
67 * GPIO/PWM interrupts are not masked on reset: as the MAX7360 "INTI"
68 * interrupt line is shared between GPIOs and rotary encoder, this could
69 * result in repeated spurious interrupts on the rotary encoder driver
70 * if the GPIO driver is not loaded. Mask them now to avoid this
71 * situation.
72 */
73 for (unsigned int i = 0; i < MAX7360_PORT_PWM_COUNT; i++) {
74 ret = regmap_write_bits(regmap, MAX7360_REG_PWMCFG(i),
75 MAX7360_PORT_CFG_INTERRUPT_MASK,
76 MAX7360_PORT_CFG_INTERRUPT_MASK);
77 if (ret)
78 return dev_err_probe(dev, ret,
79 "Failed to write MAX7360 port configuration\n");
80 }
81
82 /* Read GPIO in register, to ACK any pending IRQ. */
83 ret = regmap_read(regmap, MAX7360_REG_GPIOIN, &val);
84 if (ret)
85 return dev_err_probe(dev, ret, "Failed to read GPIO values\n");
86
87 return 0;
88}
89
90static int max7360_reset(struct regmap *regmap)
91{
92 struct device *dev = regmap_get_device(regmap);
93 int ret;
94
95 ret = regmap_write(regmap, MAX7360_REG_GPIOCFG, MAX7360_GPIO_CFG_GPIO_RST);
96 if (ret) {
97 dev_err(dev, "Failed to reset GPIO configuration: %x\n", ret);
98 return ret;
99 }
100
101 ret = regcache_drop_region(regmap, MAX7360_REG_GPIOCFG, MAX7360_REG_GPIO_LAST);
102 if (ret) {
103 dev_err(dev, "Failed to drop regmap cache: %x\n", ret);
104 return ret;
105 }
106
107 ret = regmap_write(regmap, MAX7360_REG_SLEEP, 0);
108 if (ret) {
109 dev_err(dev, "Failed to reset autosleep configuration: %x\n", ret);
110 return ret;
111 }
112
113 ret = regmap_write(regmap, MAX7360_REG_DEBOUNCE, 0);
114 if (ret)
115 dev_err(dev, "Failed to reset GPO port count: %x\n", ret);
116
117 return ret;
118}
119
120static int max7360_probe(struct i2c_client *client)
121{
122 struct device *dev = &client->dev;
123 struct regmap *regmap;
124 int ret;
125
126 regmap = devm_regmap_init_i2c(client, &max7360_regmap_config);
127 if (IS_ERR(regmap))
128 return dev_err_probe(dev, PTR_ERR(regmap), "Failed to initialise regmap\n");
129
130 ret = max7360_reset(regmap);
131 if (ret)
132 return dev_err_probe(dev, ret, "Failed to reset device\n");
133
134 /* Get the device out of shutdown mode. */
135 ret = regmap_write_bits(regmap, MAX7360_REG_GPIOCFG,
136 MAX7360_GPIO_CFG_GPIO_EN,
137 MAX7360_GPIO_CFG_GPIO_EN);
138 if (ret)
139 return dev_err_probe(dev, ret, "Failed to enable GPIO and PWM module\n");
140
141 ret = max7360_mask_irqs(regmap);
142 if (ret)
143 return dev_err_probe(dev, ret, "Could not mask interrupts\n");
144
145 ret = devm_mfd_add_devices(dev, PLATFORM_DEVID_NONE,
146 max7360_cells, ARRAY_SIZE(max7360_cells),
147 NULL, 0, NULL);
148 if (ret)
149 return dev_err_probe(dev, ret, "Failed to register child devices\n");
150
151 return 0;
152}
153
154static const struct of_device_id max7360_dt_match[] = {
155 { .compatible = "maxim,max7360" },
156 {}
157};
158MODULE_DEVICE_TABLE(of, max7360_dt_match);
159
160static struct i2c_driver max7360_driver = {
161 .driver = {
162 .name = "max7360",
163 .of_match_table = max7360_dt_match,
164 },
165 .probe = max7360_probe,
166};
167module_i2c_driver(max7360_driver);
168
169MODULE_DESCRIPTION("Maxim MAX7360 I2C IO Expander core driver");
170MODULE_AUTHOR("Kamel Bouhara <kamel.bouhara@bootlin.com>");
171MODULE_LICENSE("GPL");