1 // SPDX-License-Identifier: GPL-2.0
2 //
3 // Copyright (C) 2018 BayLibre SAS
4 // Author: Bartosz Golaszewski <bgolaszewski@baylibre.com>
5 //
6 // GPIO driver for MAXIM 77650/77651 charger/power-supply.
7
8 #include <linux/gpio/driver.h>
9 #include <linux/i2c.h>
10 #include <linux/mfd/max77650.h>
11 #include <linux/module.h>
12 #include <linux/platform_device.h>
13 #include <linux/regmap.h>
14
15 #define MAX77650_GPIO_DIR_MASK BIT(0)
16 #define MAX77650_GPIO_INVAL_MASK BIT(1)
17 #define MAX77650_GPIO_DRV_MASK BIT(2)
18 #define MAX77650_GPIO_OUTVAL_MASK BIT(3)
19 #define MAX77650_GPIO_DEBOUNCE_MASK BIT(4)
20
21 #define MAX77650_GPIO_DIR_OUT 0x00
22 #define MAX77650_GPIO_DIR_IN BIT(0)
23 #define MAX77650_GPIO_OUT_LOW 0x00
24 #define MAX77650_GPIO_OUT_HIGH BIT(3)
25 #define MAX77650_GPIO_DRV_OPEN_DRAIN 0x00
26 #define MAX77650_GPIO_DRV_PUSH_PULL BIT(2)
27 #define MAX77650_GPIO_DEBOUNCE BIT(4)
28
29 #define MAX77650_GPIO_DIR_BITS(_reg) \
30 ((_reg) & MAX77650_GPIO_DIR_MASK)
31 #define MAX77650_GPIO_INVAL_BITS(_reg) \
32 (((_reg) & MAX77650_GPIO_INVAL_MASK) >> 1)
33
34 struct max77650_gpio_chip {
35 struct regmap *map;
36 struct gpio_chip gc;
37 int irq;
38 };
39
max77650_gpio_direction_input(struct gpio_chip * gc,unsigned int offset)40 static int max77650_gpio_direction_input(struct gpio_chip *gc,
41 unsigned int offset)
42 {
43 struct max77650_gpio_chip *chip = gpiochip_get_data(gc);
44
45 return regmap_update_bits(chip->map,
46 MAX77650_REG_CNFG_GPIO,
47 MAX77650_GPIO_DIR_MASK,
48 MAX77650_GPIO_DIR_IN);
49 }
50
max77650_gpio_direction_output(struct gpio_chip * gc,unsigned int offset,int value)51 static int max77650_gpio_direction_output(struct gpio_chip *gc,
52 unsigned int offset, int value)
53 {
54 struct max77650_gpio_chip *chip = gpiochip_get_data(gc);
55 int mask, regval;
56
57 mask = MAX77650_GPIO_DIR_MASK | MAX77650_GPIO_OUTVAL_MASK;
58 regval = value ? MAX77650_GPIO_OUT_HIGH : MAX77650_GPIO_OUT_LOW;
59 regval |= MAX77650_GPIO_DIR_OUT;
60
61 return regmap_update_bits(chip->map,
62 MAX77650_REG_CNFG_GPIO, mask, regval);
63 }
64
max77650_gpio_set_value(struct gpio_chip * gc,unsigned int offset,int value)65 static int max77650_gpio_set_value(struct gpio_chip *gc,
66 unsigned int offset, int value)
67 {
68 struct max77650_gpio_chip *chip = gpiochip_get_data(gc);
69 int regval;
70
71 regval = value ? MAX77650_GPIO_OUT_HIGH : MAX77650_GPIO_OUT_LOW;
72
73 return regmap_update_bits(chip->map, MAX77650_REG_CNFG_GPIO,
74 MAX77650_GPIO_OUTVAL_MASK, regval);
75 }
76
max77650_gpio_get_value(struct gpio_chip * gc,unsigned int offset)77 static int max77650_gpio_get_value(struct gpio_chip *gc,
78 unsigned int offset)
79 {
80 struct max77650_gpio_chip *chip = gpiochip_get_data(gc);
81 unsigned int val;
82 int rv;
83
84 rv = regmap_read(chip->map, MAX77650_REG_CNFG_GPIO, &val);
85 if (rv)
86 return rv;
87
88 return MAX77650_GPIO_INVAL_BITS(val);
89 }
90
max77650_gpio_get_direction(struct gpio_chip * gc,unsigned int offset)91 static int max77650_gpio_get_direction(struct gpio_chip *gc,
92 unsigned int offset)
93 {
94 struct max77650_gpio_chip *chip = gpiochip_get_data(gc);
95 unsigned int val;
96 int rv;
97
98 rv = regmap_read(chip->map, MAX77650_REG_CNFG_GPIO, &val);
99 if (rv)
100 return rv;
101
102 return MAX77650_GPIO_DIR_BITS(val);
103 }
104
max77650_gpio_set_config(struct gpio_chip * gc,unsigned int offset,unsigned long cfg)105 static int max77650_gpio_set_config(struct gpio_chip *gc,
106 unsigned int offset, unsigned long cfg)
107 {
108 struct max77650_gpio_chip *chip = gpiochip_get_data(gc);
109
110 switch (pinconf_to_config_param(cfg)) {
111 case PIN_CONFIG_DRIVE_OPEN_DRAIN:
112 return regmap_update_bits(chip->map,
113 MAX77650_REG_CNFG_GPIO,
114 MAX77650_GPIO_DRV_MASK,
115 MAX77650_GPIO_DRV_OPEN_DRAIN);
116 case PIN_CONFIG_DRIVE_PUSH_PULL:
117 return regmap_update_bits(chip->map,
118 MAX77650_REG_CNFG_GPIO,
119 MAX77650_GPIO_DRV_MASK,
120 MAX77650_GPIO_DRV_PUSH_PULL);
121 case PIN_CONFIG_INPUT_DEBOUNCE:
122 return regmap_update_bits(chip->map,
123 MAX77650_REG_CNFG_GPIO,
124 MAX77650_GPIO_DEBOUNCE_MASK,
125 MAX77650_GPIO_DEBOUNCE);
126 default:
127 return -ENOTSUPP;
128 }
129 }
130
max77650_gpio_to_irq(struct gpio_chip * gc,unsigned int offset)131 static int max77650_gpio_to_irq(struct gpio_chip *gc, unsigned int offset)
132 {
133 struct max77650_gpio_chip *chip = gpiochip_get_data(gc);
134
135 return chip->irq;
136 }
137
max77650_gpio_probe(struct platform_device * pdev)138 static int max77650_gpio_probe(struct platform_device *pdev)
139 {
140 struct max77650_gpio_chip *chip;
141 struct device *dev, *parent;
142 struct i2c_client *i2c;
143
144 dev = &pdev->dev;
145 parent = dev->parent;
146 i2c = to_i2c_client(parent);
147
148 chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
149 if (!chip)
150 return -ENOMEM;
151
152 chip->map = dev_get_regmap(parent, NULL);
153 if (!chip->map)
154 return -ENODEV;
155
156 chip->irq = platform_get_irq_byname(pdev, "GPI");
157 if (chip->irq < 0)
158 return chip->irq;
159
160 chip->gc.base = -1;
161 chip->gc.ngpio = 1;
162 chip->gc.label = i2c->name;
163 chip->gc.parent = dev;
164 chip->gc.owner = THIS_MODULE;
165 chip->gc.can_sleep = true;
166
167 chip->gc.direction_input = max77650_gpio_direction_input;
168 chip->gc.direction_output = max77650_gpio_direction_output;
169 chip->gc.set_rv = max77650_gpio_set_value;
170 chip->gc.get = max77650_gpio_get_value;
171 chip->gc.get_direction = max77650_gpio_get_direction;
172 chip->gc.set_config = max77650_gpio_set_config;
173 chip->gc.to_irq = max77650_gpio_to_irq;
174
175 return devm_gpiochip_add_data(dev, &chip->gc, chip);
176 }
177
178 static struct platform_driver max77650_gpio_driver = {
179 .driver = {
180 .name = "max77650-gpio",
181 },
182 .probe = max77650_gpio_probe,
183 };
184 module_platform_driver(max77650_gpio_driver);
185
186 MODULE_DESCRIPTION("MAXIM 77650/77651 GPIO driver");
187 MODULE_AUTHOR("Bartosz Golaszewski <bgolaszewski@baylibre.com>");
188 MODULE_LICENSE("GPL v2");
189 MODULE_ALIAS("platform:max77650-gpio");
190