xref: /openbmc/linux/drivers/gpio/gpio-74xx-mmio.c (revision 151f4e2b)
1 /*
2  * 74xx MMIO GPIO driver
3  *
4  *  Copyright (C) 2014 Alexander Shiyan <shc_work@mail.ru>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  */
11 
12 #include <linux/err.h>
13 #include <linux/module.h>
14 #include <linux/of_device.h>
15 #include <linux/gpio/driver.h>
16 #include <linux/platform_device.h>
17 
18 #define MMIO_74XX_DIR_IN	(0 << 8)
19 #define MMIO_74XX_DIR_OUT	(1 << 8)
20 #define MMIO_74XX_BIT_CNT(x)	((x) & 0xff)
21 
22 struct mmio_74xx_gpio_priv {
23 	struct gpio_chip	gc;
24 	unsigned		flags;
25 };
26 
27 static const struct of_device_id mmio_74xx_gpio_ids[] = {
28 	{
29 		.compatible	= "ti,741g125",
30 		.data		= (const void *)(MMIO_74XX_DIR_IN | 1),
31 	},
32 	{
33 		.compatible	= "ti,742g125",
34 		.data		= (const void *)(MMIO_74XX_DIR_IN | 2),
35 	},
36 	{
37 		.compatible	= "ti,74125",
38 		.data		= (const void *)(MMIO_74XX_DIR_IN | 4),
39 	},
40 	{
41 		.compatible	= "ti,74365",
42 		.data		= (const void *)(MMIO_74XX_DIR_IN | 6),
43 	},
44 	{
45 		.compatible	= "ti,74244",
46 		.data		= (const void *)(MMIO_74XX_DIR_IN | 8),
47 	},
48 	{
49 		.compatible	= "ti,741624",
50 		.data		= (const void *)(MMIO_74XX_DIR_IN | 16),
51 	},
52 	{
53 		.compatible	= "ti,741g74",
54 		.data		= (const void *)(MMIO_74XX_DIR_OUT | 1),
55 	},
56 	{
57 		.compatible	= "ti,7474",
58 		.data		= (const void *)(MMIO_74XX_DIR_OUT | 2),
59 	},
60 	{
61 		.compatible	= "ti,74175",
62 		.data		= (const void *)(MMIO_74XX_DIR_OUT | 4),
63 	},
64 	{
65 		.compatible	= "ti,74174",
66 		.data		= (const void *)(MMIO_74XX_DIR_OUT | 6),
67 	},
68 	{
69 		.compatible	= "ti,74273",
70 		.data		= (const void *)(MMIO_74XX_DIR_OUT | 8),
71 	},
72 	{
73 		.compatible	= "ti,7416374",
74 		.data		= (const void *)(MMIO_74XX_DIR_OUT | 16),
75 	},
76 	{ }
77 };
78 MODULE_DEVICE_TABLE(of, mmio_74xx_gpio_ids);
79 
80 static int mmio_74xx_get_direction(struct gpio_chip *gc, unsigned offset)
81 {
82 	struct mmio_74xx_gpio_priv *priv = gpiochip_get_data(gc);
83 
84 	return !(priv->flags & MMIO_74XX_DIR_OUT);
85 }
86 
87 static int mmio_74xx_dir_in(struct gpio_chip *gc, unsigned int gpio)
88 {
89 	struct mmio_74xx_gpio_priv *priv = gpiochip_get_data(gc);
90 
91 	return (priv->flags & MMIO_74XX_DIR_OUT) ? -ENOTSUPP : 0;
92 }
93 
94 static int mmio_74xx_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
95 {
96 	struct mmio_74xx_gpio_priv *priv = gpiochip_get_data(gc);
97 
98 	if (priv->flags & MMIO_74XX_DIR_OUT) {
99 		gc->set(gc, gpio, val);
100 		return 0;
101 	}
102 
103 	return -ENOTSUPP;
104 }
105 
106 static int mmio_74xx_gpio_probe(struct platform_device *pdev)
107 {
108 	struct mmio_74xx_gpio_priv *priv;
109 	void __iomem *dat;
110 	int err;
111 
112 	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
113 	if (!priv)
114 		return -ENOMEM;
115 
116 	priv->flags = (uintptr_t)of_device_get_match_data(&pdev->dev);
117 
118 	dat = devm_platform_ioremap_resource(pdev, 0);
119 	if (IS_ERR(dat))
120 		return PTR_ERR(dat);
121 
122 	err = bgpio_init(&priv->gc, &pdev->dev,
123 			 DIV_ROUND_UP(MMIO_74XX_BIT_CNT(priv->flags), 8),
124 			 dat, NULL, NULL, NULL, NULL, 0);
125 	if (err)
126 		return err;
127 
128 	priv->gc.direction_input = mmio_74xx_dir_in;
129 	priv->gc.direction_output = mmio_74xx_dir_out;
130 	priv->gc.get_direction = mmio_74xx_get_direction;
131 	priv->gc.ngpio = MMIO_74XX_BIT_CNT(priv->flags);
132 	priv->gc.owner = THIS_MODULE;
133 
134 	platform_set_drvdata(pdev, priv);
135 
136 	return devm_gpiochip_add_data(&pdev->dev, &priv->gc, priv);
137 }
138 
139 static struct platform_driver mmio_74xx_gpio_driver = {
140 	.driver	= {
141 		.name		= "74xx-mmio-gpio",
142 		.of_match_table	= mmio_74xx_gpio_ids,
143 	},
144 	.probe	= mmio_74xx_gpio_probe,
145 };
146 module_platform_driver(mmio_74xx_gpio_driver);
147 
148 MODULE_LICENSE("GPL");
149 MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
150 MODULE_DESCRIPTION("74xx MMIO GPIO driver");
151