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
23struct mmio_74xx_gpio_priv {
24	struct bgpio_chip	bgc;
25	unsigned		flags;
26};
27
28static 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};
79MODULE_DEVICE_TABLE(of, mmio_74xx_gpio_ids);
80
81static 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
88static 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
95static 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
102static 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
114static 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
151static 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
158static 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};
166module_platform_driver(mmio_74xx_gpio_driver);
167
168MODULE_LICENSE("GPL");
169MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
170MODULE_DESCRIPTION("74xx MMIO GPIO driver");
171