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/gpio/generic.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 * @gen_gc: Associated gpio_generic_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_generic_chip gen_gc;
24 void __iomem *data;
25 void __iomem *dir[2];
26 void __iomem *output;
27 };
28
airoha_dir_set(struct gpio_chip * gc,unsigned int gpio,int val,int out)29 static int airoha_dir_set(struct gpio_chip *gc, unsigned int gpio,
30 int val, int out)
31 {
32 struct airoha_gpio_ctrl *ctrl = gpiochip_get_data(gc);
33 u32 dir = ioread32(ctrl->dir[gpio / 16]);
34 u32 output = ioread32(ctrl->output);
35 u32 mask = BIT((gpio % 16) * 2);
36
37 if (out) {
38 dir |= mask;
39 output |= BIT(gpio);
40 } else {
41 dir &= ~mask;
42 output &= ~BIT(gpio);
43 }
44
45 iowrite32(dir, ctrl->dir[gpio / 16]);
46
47 if (out)
48 gpio_generic_chip_set(&ctrl->gen_gc, gpio, val);
49
50 iowrite32(output, ctrl->output);
51
52 return 0;
53 }
54
airoha_dir_out(struct gpio_chip * gc,unsigned int gpio,int val)55 static int airoha_dir_out(struct gpio_chip *gc, unsigned int gpio,
56 int val)
57 {
58 return airoha_dir_set(gc, gpio, val, 1);
59 }
60
airoha_dir_in(struct gpio_chip * gc,unsigned int gpio)61 static int airoha_dir_in(struct gpio_chip *gc, unsigned int gpio)
62 {
63 return airoha_dir_set(gc, gpio, 0, 0);
64 }
65
airoha_get_dir(struct gpio_chip * gc,unsigned int gpio)66 static int airoha_get_dir(struct gpio_chip *gc, unsigned int gpio)
67 {
68 struct airoha_gpio_ctrl *ctrl = gpiochip_get_data(gc);
69 u32 dir = ioread32(ctrl->dir[gpio / 16]);
70 u32 mask = BIT((gpio % 16) * 2);
71
72 return (dir & mask) ? GPIO_LINE_DIRECTION_OUT : GPIO_LINE_DIRECTION_IN;
73 }
74
airoha_gpio_probe(struct platform_device * pdev)75 static int airoha_gpio_probe(struct platform_device *pdev)
76 {
77 struct gpio_generic_chip_config config = { };
78 struct device *dev = &pdev->dev;
79 struct airoha_gpio_ctrl *ctrl;
80 int err;
81
82 ctrl = devm_kzalloc(dev, sizeof(*ctrl), GFP_KERNEL);
83 if (!ctrl)
84 return -ENOMEM;
85
86 ctrl->data = devm_platform_ioremap_resource(pdev, 0);
87 if (IS_ERR(ctrl->data))
88 return PTR_ERR(ctrl->data);
89
90 ctrl->dir[0] = devm_platform_ioremap_resource(pdev, 1);
91 if (IS_ERR(ctrl->dir[0]))
92 return PTR_ERR(ctrl->dir[0]);
93
94 ctrl->dir[1] = devm_platform_ioremap_resource(pdev, 2);
95 if (IS_ERR(ctrl->dir[1]))
96 return PTR_ERR(ctrl->dir[1]);
97
98 ctrl->output = devm_platform_ioremap_resource(pdev, 3);
99 if (IS_ERR(ctrl->output))
100 return PTR_ERR(ctrl->output);
101
102 config.dev = dev;
103 config.sz = 4;
104 config.dat = ctrl->data;
105
106 err = gpio_generic_chip_init(&ctrl->gen_gc, &config);
107 if (err)
108 return dev_err_probe(dev, err, "unable to init generic GPIO");
109
110 ctrl->gen_gc.gc.ngpio = AIROHA_GPIO_MAX;
111 ctrl->gen_gc.gc.owner = THIS_MODULE;
112 ctrl->gen_gc.gc.direction_output = airoha_dir_out;
113 ctrl->gen_gc.gc.direction_input = airoha_dir_in;
114 ctrl->gen_gc.gc.get_direction = airoha_get_dir;
115
116 return devm_gpiochip_add_data(dev, &ctrl->gen_gc.gc, ctrl);
117 }
118
119 static const struct of_device_id airoha_gpio_of_match[] = {
120 { .compatible = "airoha,en7523-gpio" },
121 { }
122 };
123 MODULE_DEVICE_TABLE(of, airoha_gpio_of_match);
124
125 static struct platform_driver airoha_gpio_driver = {
126 .driver = {
127 .name = "airoha-gpio",
128 .of_match_table = airoha_gpio_of_match,
129 },
130 .probe = airoha_gpio_probe,
131 };
132 module_platform_driver(airoha_gpio_driver);
133
134 MODULE_DESCRIPTION("Airoha GPIO support");
135 MODULE_AUTHOR("John Crispin <john@phrozen.org>");
136 MODULE_LICENSE("GPL v2");
137