summaryrefslogtreecommitdiff
path: root/drivers/gpio/gpio-tps65219.c
blob: 7b38aa36011284ff735296257692fe29d0d3452e (plain) (blame)
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
// SPDX-License-Identifier: GPL-2.0
/*
 * GPIO driver for TI TPS65219 PMICs
 *
 * Copyright (C) 2022 Texas Instruments Incorporated - http://www.ti.com/
 */

#include <linux/bits.h>
#include <linux/gpio/driver.h>
#include <linux/mfd/tps65219.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>

#define TPS65219_GPIO0_DIR_MASK		BIT(3)
#define TPS65219_GPIO0_OFFSET		2
#define TPS65219_GPIO0_IDX		0
#define TPS65219_GPIO_DIR_IN		1
#define TPS65219_GPIO_DIR_OUT		0

struct tps65219_gpio {
	struct gpio_chip gpio_chip;
	struct tps65219 *tps;
};

static int tps65219_gpio_get_direction(struct gpio_chip *gc, unsigned int offset)
{
	struct tps65219_gpio *gpio = gpiochip_get_data(gc);
	int ret, val;

	if (offset != TPS65219_GPIO0_IDX)
		return GPIO_LINE_DIRECTION_OUT;

	ret = regmap_read(gpio->tps->regmap, TPS65219_REG_MFP_1_CONFIG, &val);
	if (ret)
		return ret;

	return !!(val & TPS65219_GPIO0_DIR_MASK);
}

static int tps65219_gpio_get(struct gpio_chip *gc, unsigned int offset)
{
	struct tps65219_gpio *gpio = gpiochip_get_data(gc);
	struct device *dev = gpio->tps->dev;
	int ret, val;

	if (offset != TPS65219_GPIO0_IDX) {
		dev_err(dev, "GPIO%d is output only, cannot get\n", offset);
		return -ENOTSUPP;
	}

	ret = regmap_read(gpio->tps->regmap, TPS65219_REG_MFP_CTRL, &val);
	if (ret)
		return ret;

	ret = !!(val & BIT(TPS65219_MFP_GPIO_STATUS_MASK));
	dev_warn(dev, "GPIO%d = %d, MULTI_DEVICE_ENABLE, not a standard GPIO\n", offset, ret);

	/*
	 * Depending on NVM config, return an error if direction is output, otherwise the GPIO0
	 * status bit.
	 */

	if (tps65219_gpio_get_direction(gc, offset) == TPS65219_GPIO_DIR_OUT)
		return -ENOTSUPP;

	return ret;
}

static void tps65219_gpio_set(struct gpio_chip *gc, unsigned int offset, int value)
{
	struct tps65219_gpio *gpio = gpiochip_get_data(gc);
	struct device *dev = gpio->tps->dev;
	int v, mask, bit;

	bit = (offset == TPS65219_GPIO0_IDX) ? TPS65219_GPIO0_OFFSET : offset - 1;

	mask = BIT(bit);
	v = value ? mask : 0;

	if (regmap_update_bits(gpio->tps->regmap, TPS65219_REG_GENERAL_CONFIG, mask, v))
		dev_err(dev, "GPIO%d, set to value %d failed.\n", offset, value);
}

static int tps65219_gpio_change_direction(struct gpio_chip *gc, unsigned int offset,
					  unsigned int direction)
{
	struct tps65219_gpio *gpio = gpiochip_get_data(gc);
	struct device *dev = gpio->tps->dev;

	/*
	 * Documentation is stating that GPIO0 direction must not be changed in Linux:
	 * Table 8-34. MFP_1_CONFIG(3): MULTI_DEVICE_ENABLE, should only be changed in INITIALIZE
	 * state (prior to ON Request).
	 * Set statically by NVM, changing direction in application can cause a hang.
	 * Below can be used for test purpose only.
	 */

	if (IS_ENABLED(CONFIG_DEBUG_GPIO)) {
		int ret = regmap_update_bits(gpio->tps->regmap, TPS65219_REG_MFP_1_CONFIG,
					     TPS65219_GPIO0_DIR_MASK, direction);
		if (ret) {
			dev_err(dev,
				"GPIO DEBUG enabled: Fail to change direction to %u for GPIO%d.\n",
				direction, offset);
			return ret;
		}
	}

	dev_err(dev,
		"GPIO%d direction set by NVM, change to %u failed, not allowed by specification\n",
		 offset, direction);

	return -ENOTSUPP;
}

static int tps65219_gpio_direction_input(struct gpio_chip *gc, unsigned int offset)
{
	struct tps65219_gpio *gpio = gpiochip_get_data(gc);
	struct device *dev = gpio->tps->dev;

	if (offset != TPS65219_GPIO0_IDX) {
		dev_err(dev, "GPIO%d is output only, cannot change to input\n", offset);
		return -ENOTSUPP;
	}

	if (tps65219_gpio_get_direction(gc, offset) == TPS65219_GPIO_DIR_IN)
		return 0;

	return tps65219_gpio_change_direction(gc, offset, TPS65219_GPIO_DIR_IN);
}

static int tps65219_gpio_direction_output(struct gpio_chip *gc, unsigned int offset, int value)
{
	tps65219_gpio_set(gc, offset, value);
	if (offset != TPS65219_GPIO0_IDX)
		return 0;

	if (tps65219_gpio_get_direction(gc, offset) == TPS65219_GPIO_DIR_OUT)
		return 0;

	return tps65219_gpio_change_direction(gc, offset, TPS65219_GPIO_DIR_OUT);
}

static const struct gpio_chip tps65219_template_chip = {
	.label			= "tps65219-gpio",
	.owner			= THIS_MODULE,
	.get_direction		= tps65219_gpio_get_direction,
	.direction_input	= tps65219_gpio_direction_input,
	.direction_output	= tps65219_gpio_direction_output,
	.get			= tps65219_gpio_get,
	.set			= tps65219_gpio_set,
	.base			= -1,
	.ngpio			= 3,
	.can_sleep		= true,
};

static int tps65219_gpio_probe(struct platform_device *pdev)
{
	struct tps65219 *tps = dev_get_drvdata(pdev->dev.parent);
	struct tps65219_gpio *gpio;

	gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
	if (!gpio)
		return -ENOMEM;

	gpio->tps = tps;
	gpio->gpio_chip = tps65219_template_chip;
	gpio->gpio_chip.parent = tps->dev;

	return devm_gpiochip_add_data(&pdev->dev, &gpio->gpio_chip, gpio);
}

static struct platform_driver tps65219_gpio_driver = {
	.driver = {
		.name = "tps65219-gpio",
	},
	.probe = tps65219_gpio_probe,
};
module_platform_driver(tps65219_gpio_driver);

MODULE_ALIAS("platform:tps65219-gpio");
MODULE_AUTHOR("Jonathan Cormier <jcormier@criticallink.com>");
MODULE_DESCRIPTION("TPS65219 GPIO driver");
MODULE_LICENSE("GPL");