File: gpio-74xx-mmio.c

package info (click to toggle)
linux 4.19.20-1
  • links: PTS, VCS
  • area: main
  • in suites: buster
  • size: 954,852 kB
  • sloc: ansic: 16,749,828; asm: 271,286; makefile: 38,257; sh: 32,808; perl: 27,671; python: 21,022; cpp: 5,063; yacc: 4,648; lex: 2,585; awk: 1,385; ruby: 25; sed: 5
file content (152 lines) | stat: -rw-r--r-- 3,720 bytes parent folder | download | duplicates (7)
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
/*
 * 74xx MMIO GPIO driver
 *
 *  Copyright (C) 2014 Alexander Shiyan <shc_work@mail.ru>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */

#include <linux/err.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/gpio/driver.h>
#include <linux/platform_device.h>

#define MMIO_74XX_DIR_IN	(0 << 8)
#define MMIO_74XX_DIR_OUT	(1 << 8)
#define MMIO_74XX_BIT_CNT(x)	((x) & 0xff)

struct mmio_74xx_gpio_priv {
	struct gpio_chip	gc;
	unsigned		flags;
};

static const struct of_device_id mmio_74xx_gpio_ids[] = {
	{
		.compatible	= "ti,741g125",
		.data		= (const void *)(MMIO_74XX_DIR_IN | 1),
	},
	{
		.compatible	= "ti,742g125",
		.data		= (const void *)(MMIO_74XX_DIR_IN | 2),
	},
	{
		.compatible	= "ti,74125",
		.data		= (const void *)(MMIO_74XX_DIR_IN | 4),
	},
	{
		.compatible	= "ti,74365",
		.data		= (const void *)(MMIO_74XX_DIR_IN | 6),
	},
	{
		.compatible	= "ti,74244",
		.data		= (const void *)(MMIO_74XX_DIR_IN | 8),
	},
	{
		.compatible	= "ti,741624",
		.data		= (const void *)(MMIO_74XX_DIR_IN | 16),
	},
	{
		.compatible	= "ti,741g74",
		.data		= (const void *)(MMIO_74XX_DIR_OUT | 1),
	},
	{
		.compatible	= "ti,7474",
		.data		= (const void *)(MMIO_74XX_DIR_OUT | 2),
	},
	{
		.compatible	= "ti,74175",
		.data		= (const void *)(MMIO_74XX_DIR_OUT | 4),
	},
	{
		.compatible	= "ti,74174",
		.data		= (const void *)(MMIO_74XX_DIR_OUT | 6),
	},
	{
		.compatible	= "ti,74273",
		.data		= (const void *)(MMIO_74XX_DIR_OUT | 8),
	},
	{
		.compatible	= "ti,7416374",
		.data		= (const void *)(MMIO_74XX_DIR_OUT | 16),
	},
	{ }
};
MODULE_DEVICE_TABLE(of, mmio_74xx_gpio_ids);

static int mmio_74xx_get_direction(struct gpio_chip *gc, unsigned offset)
{
	struct mmio_74xx_gpio_priv *priv = gpiochip_get_data(gc);

	return !(priv->flags & MMIO_74XX_DIR_OUT);
}

static int mmio_74xx_dir_in(struct gpio_chip *gc, unsigned int gpio)
{
	struct mmio_74xx_gpio_priv *priv = gpiochip_get_data(gc);

	return (priv->flags & MMIO_74XX_DIR_OUT) ? -ENOTSUPP : 0;
}

static int mmio_74xx_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
{
	struct mmio_74xx_gpio_priv *priv = gpiochip_get_data(gc);

	if (priv->flags & MMIO_74XX_DIR_OUT) {
		gc->set(gc, gpio, val);
		return 0;
	}

	return -ENOTSUPP;
}

static int mmio_74xx_gpio_probe(struct platform_device *pdev)
{
	struct mmio_74xx_gpio_priv *priv;
	struct resource *res;
	void __iomem *dat;
	int err;

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

	priv->flags = (uintptr_t)of_device_get_match_data(&pdev->dev);

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	dat = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(dat))
		return PTR_ERR(dat);

	err = bgpio_init(&priv->gc, &pdev->dev,
			 DIV_ROUND_UP(MMIO_74XX_BIT_CNT(priv->flags), 8),
			 dat, NULL, NULL, NULL, NULL, 0);
	if (err)
		return err;

	priv->gc.direction_input = mmio_74xx_dir_in;
	priv->gc.direction_output = mmio_74xx_dir_out;
	priv->gc.get_direction = mmio_74xx_get_direction;
	priv->gc.ngpio = MMIO_74XX_BIT_CNT(priv->flags);
	priv->gc.owner = THIS_MODULE;

	platform_set_drvdata(pdev, priv);

	return devm_gpiochip_add_data(&pdev->dev, &priv->gc, priv);
}

static struct platform_driver mmio_74xx_gpio_driver = {
	.driver	= {
		.name		= "74xx-mmio-gpio",
		.of_match_table	= mmio_74xx_gpio_ids,
	},
	.probe	= mmio_74xx_gpio_probe,
};
module_platform_driver(mmio_74xx_gpio_driver);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
MODULE_DESCRIPTION("74xx MMIO GPIO driver");