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/gpio/generic.h>
12 #include <linux/mod_devicetable.h>
13 #include <linux/module.h>
14 #include <linux/platform_device.h>
15 #include <linux/property.h>
16
17 #define MMIO_74XX_DIR_IN BIT(8)
18 #define MMIO_74XX_DIR_OUT BIT(9)
19 #define MMIO_74XX_BIT_CNT(x) ((x) & GENMASK(7, 0))
20
21 struct mmio_74xx_gpio_priv {
22 struct gpio_generic_chip gen_gc;
23 unsigned int flags;
24 };
25
26 static const struct of_device_id mmio_74xx_gpio_ids[] = {
27 {
28 .compatible = "ti,741g125",
29 .data = (const void *)(MMIO_74XX_DIR_IN | 1),
30 },
31 {
32 .compatible = "ti,742g125",
33 .data = (const void *)(MMIO_74XX_DIR_IN | 2),
34 },
35 {
36 .compatible = "ti,74125",
37 .data = (const void *)(MMIO_74XX_DIR_IN | 4),
38 },
39 {
40 .compatible = "ti,74365",
41 .data = (const void *)(MMIO_74XX_DIR_IN | 6),
42 },
43 {
44 .compatible = "ti,74244",
45 .data = (const void *)(MMIO_74XX_DIR_IN | 8),
46 },
47 {
48 .compatible = "ti,741624",
49 .data = (const void *)(MMIO_74XX_DIR_IN | 16),
50 },
51 {
52 .compatible = "ti,741g74",
53 .data = (const void *)(MMIO_74XX_DIR_OUT | 1),
54 },
55 {
56 .compatible = "ti,7474",
57 .data = (const void *)(MMIO_74XX_DIR_OUT | 2),
58 },
59 {
60 .compatible = "ti,74175",
61 .data = (const void *)(MMIO_74XX_DIR_OUT | 4),
62 },
63 {
64 .compatible = "ti,74174",
65 .data = (const void *)(MMIO_74XX_DIR_OUT | 6),
66 },
67 {
68 .compatible = "ti,74273",
69 .data = (const void *)(MMIO_74XX_DIR_OUT | 8),
70 },
71 {
72 .compatible = "ti,7416374",
73 .data = (const void *)(MMIO_74XX_DIR_OUT | 16),
74 },
75 { }
76 };
77 MODULE_DEVICE_TABLE(of, mmio_74xx_gpio_ids);
78
mmio_74xx_get_direction(struct gpio_chip * gc,unsigned offset)79 static int mmio_74xx_get_direction(struct gpio_chip *gc, unsigned offset)
80 {
81 struct mmio_74xx_gpio_priv *priv = gpiochip_get_data(gc);
82
83 if (priv->flags & MMIO_74XX_DIR_OUT)
84 return GPIO_LINE_DIRECTION_OUT;
85
86 return GPIO_LINE_DIRECTION_IN;
87 }
88
mmio_74xx_dir_in(struct gpio_chip * gc,unsigned int gpio)89 static int mmio_74xx_dir_in(struct gpio_chip *gc, unsigned int gpio)
90 {
91 struct mmio_74xx_gpio_priv *priv = gpiochip_get_data(gc);
92
93 if (priv->flags & MMIO_74XX_DIR_IN)
94 return 0;
95
96 return -ENOTSUPP;
97 }
98
mmio_74xx_dir_out(struct gpio_chip * gc,unsigned int gpio,int val)99 static int mmio_74xx_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
100 {
101 struct mmio_74xx_gpio_priv *priv = gpiochip_get_data(gc);
102
103 if (priv->flags & MMIO_74XX_DIR_OUT)
104 return gpio_generic_chip_set(&priv->gen_gc, gpio, val);
105
106 return -ENOTSUPP;
107 }
108
mmio_74xx_gpio_probe(struct platform_device * pdev)109 static int mmio_74xx_gpio_probe(struct platform_device *pdev)
110 {
111 struct gpio_generic_chip_config config = { };
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 config.dev = &pdev->dev;
127 config.sz = DIV_ROUND_UP(MMIO_74XX_BIT_CNT(priv->flags), 8);
128 config.dat = dat;
129
130 err = gpio_generic_chip_init(&priv->gen_gc, &config);
131 if (err)
132 return err;
133
134 priv->gen_gc.gc.direction_input = mmio_74xx_dir_in;
135 priv->gen_gc.gc.direction_output = mmio_74xx_dir_out;
136 priv->gen_gc.gc.get_direction = mmio_74xx_get_direction;
137 priv->gen_gc.gc.ngpio = MMIO_74XX_BIT_CNT(priv->flags);
138 priv->gen_gc.gc.owner = THIS_MODULE;
139
140 return devm_gpiochip_add_data(&pdev->dev, &priv->gen_gc.gc, priv);
141 }
142
143 static struct platform_driver mmio_74xx_gpio_driver = {
144 .driver = {
145 .name = "74xx-mmio-gpio",
146 .of_match_table = mmio_74xx_gpio_ids,
147 },
148 .probe = mmio_74xx_gpio_probe,
149 };
150 module_platform_driver(mmio_74xx_gpio_driver);
151
152 MODULE_LICENSE("GPL");
153 MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
154 MODULE_DESCRIPTION("74xx MMIO GPIO driver");
155