aboutsummaryrefslogtreecommitdiff
path: root/drivers/gpio/gpio-bd70528.c
blob: 397a50d6bc654049e7c81cf8110c72c1397da3d2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2018 ROHM Semiconductors
// gpio-bd70528.c ROHM BD70528MWV gpio driver

#include <linux/gpio/driver.h>
#include <linux/mfd/rohm-bd70528.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>

#define GPIO_IN_REG(offset) (BD70528_REG_GPIO1_IN + (offset) * 2)
#define GPIO_OUT_REG(offset) (BD70528_REG_GPIO1_OUT + (offset) * 2)

struct bd70528_gpio {
	struct regmap *regmap;
	struct device *dev;
	struct gpio_chip gpio;
};

static int bd70528_set_debounce(struct bd70528_gpio *bdgpio,
				unsigned int offset, unsigned int debounce)
{
	u8 val;

	switch (debounce) {
	case 0:
		val = BD70528_DEBOUNCE_DISABLE;
		break;
	case 1 ... 15000:
		val = BD70528_DEBOUNCE_15MS;
		break;
	case 15001 ... 30000:
		val = BD70528_DEBOUNCE_30MS;
		break;
	case 30001 ... 50000:
		val = BD70528_DEBOUNCE_50MS;
		break;
	default:
		dev_err(bdgpio->dev,
			"Invalid debounce value %u\n", debounce);
		return -EINVAL;
	}
	return regmap_update_bits(bdgpio->regmap, GPIO_IN_REG(offset),
				 BD70528_DEBOUNCE_MASK, val);
}

static int bd70528_get_direction(struct gpio_chip *chip, unsigned int offset)
{
	struct bd70528_gpio *bdgpio = gpiochip_get_data(chip);
	int val, ret;

	/* Do we need to do something to IRQs here? */
	ret = regmap_read(bdgpio->regmap, GPIO_OUT_REG(offset), &val);
	if (ret) {
		dev_err(bdgpio->dev, "Could not read gpio direction\n");
		return ret;
	}
	if (val & BD70528_GPIO_OUT_EN_MASK)
		return GPIO_LINE_DIRECTION_OUT;

	return GPIO_LINE_DIRECTION_IN;
}

static int bd70528_gpio_set_config(struct gpio_chip *chip, unsigned int offset,
				   unsigned long config)
{
	struct bd70528_gpio *bdgpio = gpiochip_get_data(chip);

	switch (pinconf_to_config_param(config)) {
	case PIN_CONFIG_DRIVE_OPEN_DRAIN:
		return regmap_update_bits(bdgpio->regmap,
					  GPIO_OUT_REG(offset),
					  BD70528_GPIO_DRIVE_MASK,
					  BD70528_GPIO_OPEN_DRAIN);
		break;
	case PIN_CONFIG_DRIVE_PUSH_PULL:
		return regmap_update_bits(bdgpio->regmap,
					  GPIO_OUT_REG(offset),
					  BD70528_GPIO_DRIVE_MASK,
					  BD70528_GPIO_PUSH_PULL);
		break;
	case PIN_CONFIG_INPUT_DEBOUNCE:
		return bd70528_set_debounce(bdgpio, offset,
					    pinconf_to_config_argument(config));
		break;
	default:
		break;
	}
	return -ENOTSUPP;
}

static int bd70528_direction_input(struct gpio_chip *chip, unsigned int offset)
{
	struct bd70528_gpio *bdgpio = gpiochip_get_data(chip);

	/* Do we need to do something to IRQs here? */
	return regmap_update_bits(bdgpio->regmap, GPIO_OUT_REG(offset),
				 BD70528_GPIO_OUT_EN_MASK,
				 BD70528_GPIO_OUT_DISABLE);
}

static void bd70528_gpio_set(struct gpio_chip *chip, unsigned int offset,
			     int value)
{
	int ret;
	struct bd70528_gpio *bdgpio = gpiochip_get_data(chip);
	u8 val = (value) ? BD70528_GPIO_OUT_HI : BD70528_GPIO_OUT_LO;

	ret = regmap_update_bits(bdgpio->regmap, GPIO_OUT_REG(offset),
				 BD70528_GPIO_OUT_MASK, val);
	if (ret)
		dev_err(bdgpio->dev, "Could not set gpio to %d\n", value);
}

static int bd70528_direction_output(struct gpio_chip *chip, unsigned int offset,
				    int value)
{
	struct bd70528_gpio *bdgpio = gpiochip_get_data(chip);

	bd70528_gpio_set(chip, offset, value);
	return regmap_update_bits(bdgpio->regmap, GPIO_OUT_REG(offset),
				 BD70528_GPIO_OUT_EN_MASK,
				 BD70528_GPIO_OUT_ENABLE);
}

#define GPIO_IN_STATE_MASK(offset) (BD70528_GPIO_IN_STATE_BASE << (offset))

static int bd70528_gpio_get_o(struct bd70528_gpio *bdgpio, unsigned int offset)
{
	int ret;
	unsigned int val;

	ret = regmap_read(bdgpio->regmap, GPIO_OUT_REG(offset), &val);
	if (!ret)
		ret = !!(val & BD70528_GPIO_OUT_MASK);
	else
		dev_err(bdgpio->dev, "GPIO (out) state read failed\n");

	return ret;
}

static int bd70528_gpio_get_i(struct bd70528_gpio *bdgpio, unsigned int offset)
{
	unsigned int val;
	int ret;

	ret = regmap_read(bdgpio->regmap, BD70528_REG_GPIO_STATE, &val);

	if (!ret)
		ret = !(val & GPIO_IN_STATE_MASK(offset));
	else
		dev_err(bdgpio->dev, "GPIO (in) state read failed\n");

	return ret;
}

static int bd70528_gpio_get(struct gpio_chip *chip, unsigned int offset)
{
	int ret;
	struct bd70528_gpio *bdgpio = gpiochip_get_data(chip);

	/*
	 * There is a race condition where someone might be changing the
	 * GPIO direction after we get it but before we read the value. But
	 * application design where GPIO direction may be changed just when
	 * we read GPIO value would be pointless as reader could not know
	 * whether the returned high/low state is caused by input or output.
	 * Or then there must be other ways to mitigate the issue. Thus
	 * locking would make no sense.
	 */
	ret = bd70528_get_direction(chip, offset);
	if (ret == GPIO_LINE_DIRECTION_OUT)
		ret = bd70528_gpio_get_o(bdgpio, offset);
	else if (ret == GPIO_LINE_DIRECTION_IN)
		ret = bd70528_gpio_get_i(bdgpio, offset);
	else
		dev_err(bdgpio->dev, "failed to read GPIO direction\n");

	return ret;
}

static int bd70528_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct bd70528_gpio *bdgpio;
	int ret;

	bdgpio = devm_kzalloc(dev, sizeof(*bdgpio), GFP_KERNEL);
	if (!bdgpio)
		return -ENOMEM;
	bdgpio->dev = dev;
	bdgpio->gpio.parent = dev->parent;
	bdgpio->gpio.label = "bd70528-gpio";
	bdgpio->gpio.owner = THIS_MODULE;
	bdgpio->gpio.get_direction = bd70528_get_direction;
	bdgpio->gpio.direction_input = bd70528_direction_input;
	bdgpio->gpio.direction_output = bd70528_direction_output;
	bdgpio->gpio.set_config = bd70528_gpio_set_config;
	bdgpio->gpio.can_sleep = true;
	bdgpio->gpio.get = bd70528_gpio_get;
	bdgpio->gpio.set = bd70528_gpio_set;
	bdgpio->gpio.ngpio = 4;
	bdgpio->gpio.base = -1;
#ifdef CONFIG_OF_GPIO
	bdgpio->gpio.of_node = dev->parent->of_node;
#endif
	bdgpio->regmap = dev_get_regmap(dev->parent, NULL);
	if (!bdgpio->regmap)
		return -ENODEV;

	ret = devm_gpiochip_add_data(dev, &bdgpio->gpio, bdgpio);
	if (ret)
		dev_err(dev, "gpio_init: Failed to add bd70528-gpio\n");

	return ret;
}

static struct platform_driver bd70528_gpio = {
	.driver = {
		.name = "bd70528-gpio"
	},
	.probe = bd70528_probe,
};

module_platform_driver(bd70528_gpio);

MODULE_AUTHOR("Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>");
MODULE_DESCRIPTION("BD70528 voltage regulator driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:bd70528-gpio");