xref: /linux/drivers/gpio/gpio-en7523.c (revision 6c7353836a91b1479e6b81791cdc163fb04b4834)
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  */
22 struct airoha_gpio_ctrl {
23 	struct gpio_chip gc;
24 	void __iomem *data;
25 	void __iomem *dir[2];
26 	void __iomem *output;
27 };
28 
29 static struct airoha_gpio_ctrl *gc_to_ctrl(struct gpio_chip *gc)
30 {
31 	return container_of(gc, struct airoha_gpio_ctrl, gc);
32 }
33 
34 static 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 
60 static int airoha_dir_out(struct gpio_chip *gc, unsigned int gpio,
61 			  int val)
62 {
63 	return airoha_dir_set(gc, gpio, val, 1);
64 }
65 
66 static int airoha_dir_in(struct gpio_chip *gc, unsigned int gpio)
67 {
68 	return airoha_dir_set(gc, gpio, 0, 0);
69 }
70 
71 static 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 
80 static 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, sizeof(*ctrl), GFP_KERNEL);
87 	if (!ctrl)
88 		return -ENOMEM;
89 
90 	ctrl->data = devm_platform_ioremap_resource(pdev, 0);
91 	if (IS_ERR(ctrl->data))
92 		return PTR_ERR(ctrl->data);
93 
94 	ctrl->dir[0] = devm_platform_ioremap_resource(pdev, 1);
95 	if (IS_ERR(ctrl->dir[0]))
96 		return PTR_ERR(ctrl->dir[0]);
97 
98 	ctrl->dir[1] = devm_platform_ioremap_resource(pdev, 2);
99 	if (IS_ERR(ctrl->dir[1]))
100 		return PTR_ERR(ctrl->dir[1]);
101 
102 	ctrl->output = devm_platform_ioremap_resource(pdev, 3);
103 	if (IS_ERR(ctrl->output))
104 		return PTR_ERR(ctrl->output);
105 
106 	err = bgpio_init(&ctrl->gc, dev, 4, ctrl->data, NULL,
107 			 NULL, NULL, NULL, 0);
108 	if (err)
109 		return dev_err_probe(dev, err, "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 
120 static const struct of_device_id airoha_gpio_of_match[] = {
121 	{ .compatible = "airoha,en7523-gpio" },
122 	{ }
123 };
124 MODULE_DEVICE_TABLE(of, airoha_gpio_of_match);
125 
126 static 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 };
133 module_platform_driver(airoha_gpio_driver);
134 
135 MODULE_DESCRIPTION("Airoha GPIO support");
136 MODULE_AUTHOR("John Crispin <john@phrozen.org>");
137 MODULE_LICENSE("GPL v2");
138