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
22struct mmio_74xx_gpio_priv {
23 struct gpio_chip gc;
24 unsigned flags;
25};
26
27static 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};
78MODULE_DEVICE_TABLE(of, mmio_74xx_gpio_ids);
79
80static 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
87static 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
94static 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
106static int mmio_74xx_gpio_probe(struct platform_device *pdev)
107{
108 struct mmio_74xx_gpio_priv *priv;
109 struct resource *res;
110 void __iomem *dat;
111 int err;
112
113 priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
114 if (!priv)
115 return -ENOMEM;
116
117 priv->flags = (uintptr_t)of_device_get_match_data(&pdev->dev);
118
119 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
120 dat = devm_ioremap_resource(&pdev->dev, res);
121 if (IS_ERR(dat))
122 return PTR_ERR(dat);
123
124 err = bgpio_init(&priv->gc, &pdev->dev,
125 DIV_ROUND_UP(MMIO_74XX_BIT_CNT(priv->flags), 8),
126 dat, NULL, NULL, NULL, NULL, 0);
127 if (err)
128 return err;
129
130 priv->gc.direction_input = mmio_74xx_dir_in;
131 priv->gc.direction_output = mmio_74xx_dir_out;
132 priv->gc.get_direction = mmio_74xx_get_direction;
133 priv->gc.ngpio = MMIO_74XX_BIT_CNT(priv->flags);
134 priv->gc.owner = THIS_MODULE;
135
136 platform_set_drvdata(pdev, priv);
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