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
34struct max77650_gpio_chip {
35	struct regmap *map;
36	struct gpio_chip gc;
37	int irq;
38};
39
40static 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
51static 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
65static void 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 rv, regval;
70
71	regval = value ? MAX77650_GPIO_OUT_HIGH : MAX77650_GPIO_OUT_LOW;
72
73	rv = regmap_update_bits(chip->map, MAX77650_REG_CNFG_GPIO,
74				MAX77650_GPIO_OUTVAL_MASK, regval);
75	if (rv)
76		dev_err(gc->parent, "cannot set GPIO value: %d\n", rv);
77}
78
79static int max77650_gpio_get_value(struct gpio_chip *gc,
80				   unsigned int offset)
81{
82	struct max77650_gpio_chip *chip = gpiochip_get_data(gc);
83	unsigned int val;
84	int rv;
85
86	rv = regmap_read(chip->map, MAX77650_REG_CNFG_GPIO, &val);
87	if (rv)
88		return rv;
89
90	return MAX77650_GPIO_INVAL_BITS(val);
91}
92
93static int max77650_gpio_get_direction(struct gpio_chip *gc,
94				       unsigned int offset)
95{
96	struct max77650_gpio_chip *chip = gpiochip_get_data(gc);
97	unsigned int val;
98	int rv;
99
100	rv = regmap_read(chip->map, MAX77650_REG_CNFG_GPIO, &val);
101	if (rv)
102		return rv;
103
104	return MAX77650_GPIO_DIR_BITS(val);
105}
106
107static int max77650_gpio_set_config(struct gpio_chip *gc,
108				    unsigned int offset, unsigned long cfg)
109{
110	struct max77650_gpio_chip *chip = gpiochip_get_data(gc);
111
112	switch (pinconf_to_config_param(cfg)) {
113	case PIN_CONFIG_DRIVE_OPEN_DRAIN:
114		return regmap_update_bits(chip->map,
115					  MAX77650_REG_CNFG_GPIO,
116					  MAX77650_GPIO_DRV_MASK,
117					  MAX77650_GPIO_DRV_OPEN_DRAIN);
118	case PIN_CONFIG_DRIVE_PUSH_PULL:
119		return regmap_update_bits(chip->map,
120					  MAX77650_REG_CNFG_GPIO,
121					  MAX77650_GPIO_DRV_MASK,
122					  MAX77650_GPIO_DRV_PUSH_PULL);
123	case PIN_CONFIG_INPUT_DEBOUNCE:
124		return regmap_update_bits(chip->map,
125					  MAX77650_REG_CNFG_GPIO,
126					  MAX77650_GPIO_DEBOUNCE_MASK,
127					  MAX77650_GPIO_DEBOUNCE);
128	default:
129		return -ENOTSUPP;
130	}
131}
132
133static int max77650_gpio_to_irq(struct gpio_chip *gc, unsigned int offset)
134{
135	struct max77650_gpio_chip *chip = gpiochip_get_data(gc);
136
137	return chip->irq;
138}
139
140static int max77650_gpio_probe(struct platform_device *pdev)
141{
142	struct max77650_gpio_chip *chip;
143	struct device *dev, *parent;
144	struct i2c_client *i2c;
145
146	dev = &pdev->dev;
147	parent = dev->parent;
148	i2c = to_i2c_client(parent);
149
150	chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
151	if (!chip)
152		return -ENOMEM;
153
154	chip->map = dev_get_regmap(parent, NULL);
155	if (!chip->map)
156		return -ENODEV;
157
158	chip->irq = platform_get_irq_byname(pdev, "GPI");
159	if (chip->irq < 0)
160		return chip->irq;
161
162	chip->gc.base = -1;
163	chip->gc.ngpio = 1;
164	chip->gc.label = i2c->name;
165	chip->gc.parent = dev;
166	chip->gc.owner = THIS_MODULE;
167	chip->gc.can_sleep = true;
168
169	chip->gc.direction_input = max77650_gpio_direction_input;
170	chip->gc.direction_output = max77650_gpio_direction_output;
171	chip->gc.set = max77650_gpio_set_value;
172	chip->gc.get = max77650_gpio_get_value;
173	chip->gc.get_direction = max77650_gpio_get_direction;
174	chip->gc.set_config = max77650_gpio_set_config;
175	chip->gc.to_irq = max77650_gpio_to_irq;
176
177	return devm_gpiochip_add_data(dev, &chip->gc, chip);
178}
179
180static struct platform_driver max77650_gpio_driver = {
181	.driver = {
182		.name = "max77650-gpio",
183	},
184	.probe = max77650_gpio_probe,
185};
186module_platform_driver(max77650_gpio_driver);
187
188MODULE_DESCRIPTION("MAXIM 77650/77651 GPIO driver");
189MODULE_AUTHOR("Bartosz Golaszewski <bgolaszewski@baylibre.com>");
190MODULE_LICENSE("GPL v2");
191MODULE_ALIAS("platform:max77650-gpio");
192