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(dev: &pdev->dev, size: sizeof(*priv), GFP_KERNEL);
117 if (!priv)
118 return -ENOMEM;
119
120 priv->flags = (uintptr_t)device_get_match_data(dev: &pdev->dev);
121
122 dat = devm_platform_ioremap_resource(pdev, index: 0);
123 if (IS_ERR(ptr: dat))
124 return PTR_ERR(ptr: dat);
125
126 err = bgpio_init(gc: &priv->gc, dev: &pdev->dev,
127 DIV_ROUND_UP(MMIO_74XX_BIT_CNT(priv->flags), 8),
128 dat, NULL, NULL, NULL, NULL, flags: 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

source code of linux/drivers/gpio/gpio-74xx-mmio.c