1// SPDX-License-Identifier: GPL-2.0-only
2
3#include <linux/types.h>
4#include <linux/io.h>
5#include <linux/bits.h>
6#include <linux/gpio/driver.h>
7#include <linux/mod_devicetable.h>
8#include <linux/module.h>
9#include <linux/platform_device.h>
10#include <linux/property.h>
11
12#define AIROHA_GPIO_MAX 32
13
14/**
15 * struct airoha_gpio_ctrl - Airoha GPIO driver data
16 * @gc: Associated gpio_chip instance.
17 * @data: The data register.
18 * @dir: [0] The direction register for the lower 16 pins.
19 * [1]: The direction register for the higher 16 pins.
20 * @output: The output enable register.
21 */
22struct airoha_gpio_ctrl {
23 struct gpio_chip gc;
24 void __iomem *data;
25 void __iomem *dir[2];
26 void __iomem *output;
27};
28
29static struct airoha_gpio_ctrl *gc_to_ctrl(struct gpio_chip *gc)
30{
31 return container_of(gc, struct airoha_gpio_ctrl, gc);
32}
33
34static int airoha_dir_set(struct gpio_chip *gc, unsigned int gpio,
35 int val, int out)
36{
37 struct airoha_gpio_ctrl *ctrl = gc_to_ctrl(gc);
38 u32 dir = ioread32(ctrl->dir[gpio / 16]);
39 u32 output = ioread32(ctrl->output);
40 u32 mask = BIT((gpio % 16) * 2);
41
42 if (out) {
43 dir |= mask;
44 output |= BIT(gpio);
45 } else {
46 dir &= ~mask;
47 output &= ~BIT(gpio);
48 }
49
50 iowrite32(dir, ctrl->dir[gpio / 16]);
51
52 if (out)
53 gc->set(gc, gpio, val);
54
55 iowrite32(output, ctrl->output);
56
57 return 0;
58}
59
60static int airoha_dir_out(struct gpio_chip *gc, unsigned int gpio,
61 int val)
62{
63 return airoha_dir_set(gc, gpio, val, out: 1);
64}
65
66static int airoha_dir_in(struct gpio_chip *gc, unsigned int gpio)
67{
68 return airoha_dir_set(gc, gpio, val: 0, out: 0);
69}
70
71static int airoha_get_dir(struct gpio_chip *gc, unsigned int gpio)
72{
73 struct airoha_gpio_ctrl *ctrl = gc_to_ctrl(gc);
74 u32 dir = ioread32(ctrl->dir[gpio / 16]);
75 u32 mask = BIT((gpio % 16) * 2);
76
77 return (dir & mask) ? GPIO_LINE_DIRECTION_OUT : GPIO_LINE_DIRECTION_IN;
78}
79
80static int airoha_gpio_probe(struct platform_device *pdev)
81{
82 struct device *dev = &pdev->dev;
83 struct airoha_gpio_ctrl *ctrl;
84 int err;
85
86 ctrl = devm_kzalloc(dev, size: sizeof(*ctrl), GFP_KERNEL);
87 if (!ctrl)
88 return -ENOMEM;
89
90 ctrl->data = devm_platform_ioremap_resource(pdev, index: 0);
91 if (IS_ERR(ptr: ctrl->data))
92 return PTR_ERR(ptr: ctrl->data);
93
94 ctrl->dir[0] = devm_platform_ioremap_resource(pdev, index: 1);
95 if (IS_ERR(ptr: ctrl->dir[0]))
96 return PTR_ERR(ptr: ctrl->dir[0]);
97
98 ctrl->dir[1] = devm_platform_ioremap_resource(pdev, index: 2);
99 if (IS_ERR(ptr: ctrl->dir[1]))
100 return PTR_ERR(ptr: ctrl->dir[1]);
101
102 ctrl->output = devm_platform_ioremap_resource(pdev, index: 3);
103 if (IS_ERR(ptr: ctrl->output))
104 return PTR_ERR(ptr: ctrl->output);
105
106 err = bgpio_init(gc: &ctrl->gc, dev, sz: 4, dat: ctrl->data, NULL,
107 NULL, NULL, NULL, flags: 0);
108 if (err)
109 return dev_err_probe(dev, err, fmt: "unable to init generic GPIO");
110
111 ctrl->gc.ngpio = AIROHA_GPIO_MAX;
112 ctrl->gc.owner = THIS_MODULE;
113 ctrl->gc.direction_output = airoha_dir_out;
114 ctrl->gc.direction_input = airoha_dir_in;
115 ctrl->gc.get_direction = airoha_get_dir;
116
117 return devm_gpiochip_add_data(dev, &ctrl->gc, ctrl);
118}
119
120static const struct of_device_id airoha_gpio_of_match[] = {
121 { .compatible = "airoha,en7523-gpio" },
122 { }
123};
124MODULE_DEVICE_TABLE(of, airoha_gpio_of_match);
125
126static struct platform_driver airoha_gpio_driver = {
127 .driver = {
128 .name = "airoha-gpio",
129 .of_match_table = airoha_gpio_of_match,
130 },
131 .probe = airoha_gpio_probe,
132};
133module_platform_driver(airoha_gpio_driver);
134
135MODULE_DESCRIPTION("Airoha GPIO support");
136MODULE_AUTHOR("John Crispin <john@phrozen.org>");
137MODULE_LICENSE("GPL v2");
138

source code of linux/drivers/gpio/gpio-en7523.c