xref: /linux/drivers/gpio/gpio-74xx-mmio.c (revision e0bf6c5ca2d3281f231c5f0c9bf145e9513644de)
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/gpio.h>
14 #include <linux/module.h>
15 #include <linux/of_device.h>
16 #include <linux/basic_mmio_gpio.h>
17 #include <linux/platform_device.h>
18 
19 #define MMIO_74XX_DIR_IN	(0 << 8)
20 #define MMIO_74XX_DIR_OUT	(1 << 8)
21 #define MMIO_74XX_BIT_CNT(x)	((x) & 0xff)
22 
23 struct mmio_74xx_gpio_priv {
24 	struct bgpio_chip	bgc;
25 	unsigned		flags;
26 };
27 
28 static const struct of_device_id mmio_74xx_gpio_ids[] = {
29 	{
30 		.compatible	= "ti,741g125",
31 		.data		= (const void *)(MMIO_74XX_DIR_IN | 1),
32 	},
33 	{
34 		.compatible	= "ti,742g125",
35 		.data		= (const void *)(MMIO_74XX_DIR_IN | 2),
36 	},
37 	{
38 		.compatible	= "ti,74125",
39 		.data		= (const void *)(MMIO_74XX_DIR_IN | 4),
40 	},
41 	{
42 		.compatible	= "ti,74365",
43 		.data		= (const void *)(MMIO_74XX_DIR_IN | 6),
44 	},
45 	{
46 		.compatible	= "ti,74244",
47 		.data		= (const void *)(MMIO_74XX_DIR_IN | 8),
48 	},
49 	{
50 		.compatible	= "ti,741624",
51 		.data		= (const void *)(MMIO_74XX_DIR_IN | 16),
52 	},
53 	{
54 		.compatible	= "ti,741g74",
55 		.data		= (const void *)(MMIO_74XX_DIR_OUT | 1),
56 	},
57 	{
58 		.compatible	= "ti,7474",
59 		.data		= (const void *)(MMIO_74XX_DIR_OUT | 2),
60 	},
61 	{
62 		.compatible	= "ti,74175",
63 		.data		= (const void *)(MMIO_74XX_DIR_OUT | 4),
64 	},
65 	{
66 		.compatible	= "ti,74174",
67 		.data		= (const void *)(MMIO_74XX_DIR_OUT | 6),
68 	},
69 	{
70 		.compatible	= "ti,74273",
71 		.data		= (const void *)(MMIO_74XX_DIR_OUT | 8),
72 	},
73 	{
74 		.compatible	= "ti,7416374",
75 		.data		= (const void *)(MMIO_74XX_DIR_OUT | 16),
76 	},
77 	{ }
78 };
79 MODULE_DEVICE_TABLE(of, mmio_74xx_gpio_ids);
80 
81 static inline struct mmio_74xx_gpio_priv *to_74xx_gpio(struct gpio_chip *gc)
82 {
83 	struct bgpio_chip *bgc = to_bgpio_chip(gc);
84 
85 	return container_of(bgc, struct mmio_74xx_gpio_priv, bgc);
86 }
87 
88 static int mmio_74xx_get_direction(struct gpio_chip *gc, unsigned offset)
89 {
90 	struct mmio_74xx_gpio_priv *priv = to_74xx_gpio(gc);
91 
92 	return (priv->flags & MMIO_74XX_DIR_OUT) ? GPIOF_DIR_OUT : GPIOF_DIR_IN;
93 }
94 
95 static int mmio_74xx_dir_in(struct gpio_chip *gc, unsigned int gpio)
96 {
97 	struct mmio_74xx_gpio_priv *priv = to_74xx_gpio(gc);
98 
99 	return (priv->flags & MMIO_74XX_DIR_OUT) ? -ENOTSUPP : 0;
100 }
101 
102 static int mmio_74xx_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
103 {
104 	struct mmio_74xx_gpio_priv *priv = to_74xx_gpio(gc);
105 
106 	if (priv->flags & MMIO_74XX_DIR_OUT) {
107 		gc->set(gc, gpio, val);
108 		return 0;
109 	}
110 
111 	return -ENOTSUPP;
112 }
113 
114 static int mmio_74xx_gpio_probe(struct platform_device *pdev)
115 {
116 	const struct of_device_id *of_id =
117 		of_match_device(mmio_74xx_gpio_ids, &pdev->dev);
118 	struct mmio_74xx_gpio_priv *priv;
119 	struct resource *res;
120 	void __iomem *dat;
121 	int err;
122 
123 	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
124 	if (!priv)
125 		return -ENOMEM;
126 
127 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
128 	dat = devm_ioremap_resource(&pdev->dev, res);
129 	if (IS_ERR(dat))
130 		return PTR_ERR(dat);
131 
132 	priv->flags = (unsigned)of_id->data;
133 
134 	err = bgpio_init(&priv->bgc, &pdev->dev,
135 			 DIV_ROUND_UP(MMIO_74XX_BIT_CNT(priv->flags), 8),
136 			 dat, NULL, NULL, NULL, NULL, 0);
137 	if (err)
138 		return err;
139 
140 	priv->bgc.gc.direction_input = mmio_74xx_dir_in;
141 	priv->bgc.gc.direction_output = mmio_74xx_dir_out;
142 	priv->bgc.gc.get_direction = mmio_74xx_get_direction;
143 	priv->bgc.gc.ngpio = MMIO_74XX_BIT_CNT(priv->flags);
144 	priv->bgc.gc.owner = THIS_MODULE;
145 
146 	platform_set_drvdata(pdev, priv);
147 
148 	return gpiochip_add(&priv->bgc.gc);
149 }
150 
151 static int mmio_74xx_gpio_remove(struct platform_device *pdev)
152 {
153 	struct mmio_74xx_gpio_priv *priv = platform_get_drvdata(pdev);
154 
155 	return bgpio_remove(&priv->bgc);
156 }
157 
158 static struct platform_driver mmio_74xx_gpio_driver = {
159 	.driver	= {
160 		.name		= "74xx-mmio-gpio",
161 		.of_match_table	= mmio_74xx_gpio_ids,
162 	},
163 	.probe	= mmio_74xx_gpio_probe,
164 	.remove	= mmio_74xx_gpio_remove,
165 };
166 module_platform_driver(mmio_74xx_gpio_driver);
167 
168 MODULE_LICENSE("GPL");
169 MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
170 MODULE_DESCRIPTION("74xx MMIO GPIO driver");
171