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/bits.h>
9#include <linux/err.h>
10#include <linux/gpio/driver.h>
11#include <linux/mod_devicetable.h>
12#include <linux/module.h>
13#include <linux/platform_device.h>
14#include <linux/property.h>
15
16#define MMIO_74XX_DIR_IN	BIT(8)
17#define MMIO_74XX_DIR_OUT	BIT(9)
18#define MMIO_74XX_BIT_CNT(x)	((x) & GENMASK(7, 0))
19
20struct mmio_74xx_gpio_priv {
21	struct gpio_chip	gc;
22	unsigned		flags;
23};
24
25static const struct of_device_id mmio_74xx_gpio_ids[] = {
26	{
27		.compatible	= "ti,741g125",
28		.data		= (const void *)(MMIO_74XX_DIR_IN | 1),
29	},
30	{
31		.compatible	= "ti,742g125",
32		.data		= (const void *)(MMIO_74XX_DIR_IN | 2),
33	},
34	{
35		.compatible	= "ti,74125",
36		.data		= (const void *)(MMIO_74XX_DIR_IN | 4),
37	},
38	{
39		.compatible	= "ti,74365",
40		.data		= (const void *)(MMIO_74XX_DIR_IN | 6),
41	},
42	{
43		.compatible	= "ti,74244",
44		.data		= (const void *)(MMIO_74XX_DIR_IN | 8),
45	},
46	{
47		.compatible	= "ti,741624",
48		.data		= (const void *)(MMIO_74XX_DIR_IN | 16),
49	},
50	{
51		.compatible	= "ti,741g74",
52		.data		= (const void *)(MMIO_74XX_DIR_OUT | 1),
53	},
54	{
55		.compatible	= "ti,7474",
56		.data		= (const void *)(MMIO_74XX_DIR_OUT | 2),
57	},
58	{
59		.compatible	= "ti,74175",
60		.data		= (const void *)(MMIO_74XX_DIR_OUT | 4),
61	},
62	{
63		.compatible	= "ti,74174",
64		.data		= (const void *)(MMIO_74XX_DIR_OUT | 6),
65	},
66	{
67		.compatible	= "ti,74273",
68		.data		= (const void *)(MMIO_74XX_DIR_OUT | 8),
69	},
70	{
71		.compatible	= "ti,7416374",
72		.data		= (const void *)(MMIO_74XX_DIR_OUT | 16),
73	},
74	{ }
75};
76MODULE_DEVICE_TABLE(of, mmio_74xx_gpio_ids);
77
78static int mmio_74xx_get_direction(struct gpio_chip *gc, unsigned offset)
79{
80	struct mmio_74xx_gpio_priv *priv = gpiochip_get_data(gc);
81
82	if (priv->flags & MMIO_74XX_DIR_OUT)
83		return GPIO_LINE_DIRECTION_OUT;
84
85	return  GPIO_LINE_DIRECTION_IN;
86}
87
88static int mmio_74xx_dir_in(struct gpio_chip *gc, unsigned int gpio)
89{
90	struct mmio_74xx_gpio_priv *priv = gpiochip_get_data(gc);
91
92	if (priv->flags & MMIO_74XX_DIR_IN)
93		return 0;
94
95	return -ENOTSUPP;
96}
97
98static int mmio_74xx_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
99{
100	struct mmio_74xx_gpio_priv *priv = gpiochip_get_data(gc);
101
102	if (priv->flags & MMIO_74XX_DIR_OUT) {
103		gc->set(gc, gpio, val);
104		return 0;
105	}
106
107	return -ENOTSUPP;
108}
109
110static int mmio_74xx_gpio_probe(struct platform_device *pdev)
111{
112	struct mmio_74xx_gpio_priv *priv;
113	void __iomem *dat;
114	int err;
115
116	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
117	if (!priv)
118		return -ENOMEM;
119
120	priv->flags = (uintptr_t)device_get_match_data(&pdev->dev);
121
122	dat = devm_platform_ioremap_resource(pdev, 0);
123	if (IS_ERR(dat))
124		return PTR_ERR(dat);
125
126	err = bgpio_init(&priv->gc, &pdev->dev,
127			 DIV_ROUND_UP(MMIO_74XX_BIT_CNT(priv->flags), 8),
128			 dat, NULL, NULL, NULL, NULL, 0);
129	if (err)
130		return err;
131
132	priv->gc.direction_input = mmio_74xx_dir_in;
133	priv->gc.direction_output = mmio_74xx_dir_out;
134	priv->gc.get_direction = mmio_74xx_get_direction;
135	priv->gc.ngpio = MMIO_74XX_BIT_CNT(priv->flags);
136	priv->gc.owner = THIS_MODULE;
137
138	return devm_gpiochip_add_data(&pdev->dev, &priv->gc, priv);
139}
140
141static struct platform_driver mmio_74xx_gpio_driver = {
142	.driver	= {
143		.name		= "74xx-mmio-gpio",
144		.of_match_table	= mmio_74xx_gpio_ids,
145	},
146	.probe	= mmio_74xx_gpio_probe,
147};
148module_platform_driver(mmio_74xx_gpio_driver);
149
150MODULE_LICENSE("GPL");
151MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
152MODULE_DESCRIPTION("74xx MMIO GPIO driver");
153