1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * 74xx MMIO GPIO driver
4 *
5 *  Copyright (C) 2014 Alexander Shiyan <shc_work@mail.ru>
6 */
7
8#include <linux/err.h>
9#include <linux/module.h>
10#include <linux/of_device.h>
11#include <linux/gpio/driver.h>
12#include <linux/platform_device.h>
13
14#define MMIO_74XX_DIR_IN	(0 << 8)
15#define MMIO_74XX_DIR_OUT	(1 << 8)
16#define MMIO_74XX_BIT_CNT(x)	((x) & 0xff)
17
18struct mmio_74xx_gpio_priv {
19	struct gpio_chip	gc;
20	unsigned		flags;
21};
22
23static const struct of_device_id mmio_74xx_gpio_ids[] = {
24	{
25		.compatible	= "ti,741g125",
26		.data		= (const void *)(MMIO_74XX_DIR_IN | 1),
27	},
28	{
29		.compatible	= "ti,742g125",
30		.data		= (const void *)(MMIO_74XX_DIR_IN | 2),
31	},
32	{
33		.compatible	= "ti,74125",
34		.data		= (const void *)(MMIO_74XX_DIR_IN | 4),
35	},
36	{
37		.compatible	= "ti,74365",
38		.data		= (const void *)(MMIO_74XX_DIR_IN | 6),
39	},
40	{
41		.compatible	= "ti,74244",
42		.data		= (const void *)(MMIO_74XX_DIR_IN | 8),
43	},
44	{
45		.compatible	= "ti,741624",
46		.data		= (const void *)(MMIO_74XX_DIR_IN | 16),
47	},
48	{
49		.compatible	= "ti,741g74",
50		.data		= (const void *)(MMIO_74XX_DIR_OUT | 1),
51	},
52	{
53		.compatible	= "ti,7474",
54		.data		= (const void *)(MMIO_74XX_DIR_OUT | 2),
55	},
56	{
57		.compatible	= "ti,74175",
58		.data		= (const void *)(MMIO_74XX_DIR_OUT | 4),
59	},
60	{
61		.compatible	= "ti,74174",
62		.data		= (const void *)(MMIO_74XX_DIR_OUT | 6),
63	},
64	{
65		.compatible	= "ti,74273",
66		.data		= (const void *)(MMIO_74XX_DIR_OUT | 8),
67	},
68	{
69		.compatible	= "ti,7416374",
70		.data		= (const void *)(MMIO_74XX_DIR_OUT | 16),
71	},
72	{ }
73};
74MODULE_DEVICE_TABLE(of, mmio_74xx_gpio_ids);
75
76static int mmio_74xx_get_direction(struct gpio_chip *gc, unsigned offset)
77{
78	struct mmio_74xx_gpio_priv *priv = gpiochip_get_data(gc);
79
80	if (priv->flags & MMIO_74XX_DIR_OUT)
81		return GPIO_LINE_DIRECTION_OUT;
82
83	return  GPIO_LINE_DIRECTION_IN;
84}
85
86static int mmio_74xx_dir_in(struct gpio_chip *gc, unsigned int gpio)
87{
88	struct mmio_74xx_gpio_priv *priv = gpiochip_get_data(gc);
89
90	return (priv->flags & MMIO_74XX_DIR_OUT) ? -ENOTSUPP : 0;
91}
92
93static int mmio_74xx_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
94{
95	struct mmio_74xx_gpio_priv *priv = gpiochip_get_data(gc);
96
97	if (priv->flags & MMIO_74XX_DIR_OUT) {
98		gc->set(gc, gpio, val);
99		return 0;
100	}
101
102	return -ENOTSUPP;
103}
104
105static int mmio_74xx_gpio_probe(struct platform_device *pdev)
106{
107	struct mmio_74xx_gpio_priv *priv;
108	void __iomem *dat;
109	int err;
110
111	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
112	if (!priv)
113		return -ENOMEM;
114
115	priv->flags = (uintptr_t)of_device_get_match_data(&pdev->dev);
116
117	dat = devm_platform_ioremap_resource(pdev, 0);
118	if (IS_ERR(dat))
119		return PTR_ERR(dat);
120
121	err = bgpio_init(&priv->gc, &pdev->dev,
122			 DIV_ROUND_UP(MMIO_74XX_BIT_CNT(priv->flags), 8),
123			 dat, NULL, NULL, NULL, NULL, 0);
124	if (err)
125		return err;
126
127	priv->gc.direction_input = mmio_74xx_dir_in;
128	priv->gc.direction_output = mmio_74xx_dir_out;
129	priv->gc.get_direction = mmio_74xx_get_direction;
130	priv->gc.ngpio = MMIO_74XX_BIT_CNT(priv->flags);
131	priv->gc.owner = THIS_MODULE;
132
133	platform_set_drvdata(pdev, priv);
134
135	return devm_gpiochip_add_data(&pdev->dev, &priv->gc, priv);
136}
137
138static struct platform_driver mmio_74xx_gpio_driver = {
139	.driver	= {
140		.name		= "74xx-mmio-gpio",
141		.of_match_table	= mmio_74xx_gpio_ids,
142	},
143	.probe	= mmio_74xx_gpio_probe,
144};
145module_platform_driver(mmio_74xx_gpio_driver);
146
147MODULE_LICENSE("GPL");
148MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
149MODULE_DESCRIPTION("74xx MMIO GPIO driver");
150