1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2022 Linaro Ltd.
4 */
5
6#include <linux/device.h>
7#include <linux/module.h>
8#include <linux/mutex.h>
9#include <linux/gpio/consumer.h>
10#include <linux/platform_device.h>
11#include <linux/usb/typec_dp.h>
12#include <linux/usb/typec_mux.h>
13
14struct gpio_sbu_mux {
15 struct gpio_desc *enable_gpio;
16 struct gpio_desc *select_gpio;
17
18 struct typec_switch_dev *sw;
19 struct typec_mux_dev *mux;
20
21 struct mutex lock; /* protect enabled and swapped */
22 bool enabled;
23 bool swapped;
24};
25
26static int gpio_sbu_switch_set(struct typec_switch_dev *sw,
27 enum typec_orientation orientation)
28{
29 struct gpio_sbu_mux *sbu_mux = typec_switch_get_drvdata(sw);
30 bool enabled;
31 bool swapped;
32
33 mutex_lock(&sbu_mux->lock);
34
35 enabled = sbu_mux->enabled;
36 swapped = sbu_mux->swapped;
37
38 switch (orientation) {
39 case TYPEC_ORIENTATION_NONE:
40 enabled = false;
41 break;
42 case TYPEC_ORIENTATION_NORMAL:
43 swapped = false;
44 break;
45 case TYPEC_ORIENTATION_REVERSE:
46 swapped = true;
47 break;
48 }
49
50 if (enabled != sbu_mux->enabled)
51 gpiod_set_value(desc: sbu_mux->enable_gpio, value: enabled);
52
53 if (swapped != sbu_mux->swapped)
54 gpiod_set_value(desc: sbu_mux->select_gpio, value: swapped);
55
56 sbu_mux->enabled = enabled;
57 sbu_mux->swapped = swapped;
58
59 mutex_unlock(lock: &sbu_mux->lock);
60
61 return 0;
62}
63
64static int gpio_sbu_mux_set(struct typec_mux_dev *mux,
65 struct typec_mux_state *state)
66{
67 struct gpio_sbu_mux *sbu_mux = typec_mux_get_drvdata(mux);
68
69 mutex_lock(&sbu_mux->lock);
70
71 switch (state->mode) {
72 case TYPEC_STATE_SAFE:
73 case TYPEC_STATE_USB:
74 sbu_mux->enabled = false;
75 break;
76 case TYPEC_DP_STATE_C:
77 case TYPEC_DP_STATE_D:
78 case TYPEC_DP_STATE_E:
79 sbu_mux->enabled = true;
80 break;
81 default:
82 break;
83 }
84
85 gpiod_set_value(desc: sbu_mux->enable_gpio, value: sbu_mux->enabled);
86
87 mutex_unlock(lock: &sbu_mux->lock);
88
89 return 0;
90}
91
92static int gpio_sbu_mux_probe(struct platform_device *pdev)
93{
94 struct typec_switch_desc sw_desc = { };
95 struct typec_mux_desc mux_desc = { };
96 struct device *dev = &pdev->dev;
97 struct gpio_sbu_mux *sbu_mux;
98
99 sbu_mux = devm_kzalloc(dev, size: sizeof(*sbu_mux), GFP_KERNEL);
100 if (!sbu_mux)
101 return -ENOMEM;
102
103 mutex_init(&sbu_mux->lock);
104
105 sbu_mux->enable_gpio = devm_gpiod_get(dev, con_id: "enable", flags: GPIOD_OUT_LOW);
106 if (IS_ERR(ptr: sbu_mux->enable_gpio))
107 return dev_err_probe(dev, err: PTR_ERR(ptr: sbu_mux->enable_gpio),
108 fmt: "unable to acquire enable gpio\n");
109
110 sbu_mux->select_gpio = devm_gpiod_get(dev, con_id: "select", flags: GPIOD_OUT_LOW);
111 if (IS_ERR(ptr: sbu_mux->select_gpio))
112 return dev_err_probe(dev, err: PTR_ERR(ptr: sbu_mux->select_gpio),
113 fmt: "unable to acquire select gpio\n");
114
115 sw_desc.drvdata = sbu_mux;
116 sw_desc.fwnode = dev_fwnode(dev);
117 sw_desc.set = gpio_sbu_switch_set;
118
119 sbu_mux->sw = typec_switch_register(parent: dev, desc: &sw_desc);
120 if (IS_ERR(ptr: sbu_mux->sw))
121 return dev_err_probe(dev, err: PTR_ERR(ptr: sbu_mux->sw),
122 fmt: "failed to register typec switch\n");
123
124 mux_desc.drvdata = sbu_mux;
125 mux_desc.fwnode = dev_fwnode(dev);
126 mux_desc.set = gpio_sbu_mux_set;
127
128 sbu_mux->mux = typec_mux_register(parent: dev, desc: &mux_desc);
129 if (IS_ERR(ptr: sbu_mux->mux)) {
130 typec_switch_unregister(sw: sbu_mux->sw);
131 return dev_err_probe(dev, err: PTR_ERR(ptr: sbu_mux->mux),
132 fmt: "failed to register typec mux\n");
133 }
134
135 platform_set_drvdata(pdev, data: sbu_mux);
136
137 return 0;
138}
139
140static void gpio_sbu_mux_remove(struct platform_device *pdev)
141{
142 struct gpio_sbu_mux *sbu_mux = platform_get_drvdata(pdev);
143
144 gpiod_set_value(desc: sbu_mux->enable_gpio, value: 0);
145
146 typec_mux_unregister(mux: sbu_mux->mux);
147 typec_switch_unregister(sw: sbu_mux->sw);
148}
149
150static const struct of_device_id gpio_sbu_mux_match[] = {
151 { .compatible = "gpio-sbu-mux", },
152 {}
153};
154MODULE_DEVICE_TABLE(of, gpio_sbu_mux_match);
155
156static struct platform_driver gpio_sbu_mux_driver = {
157 .probe = gpio_sbu_mux_probe,
158 .remove_new = gpio_sbu_mux_remove,
159 .driver = {
160 .name = "gpio_sbu_mux",
161 .of_match_table = gpio_sbu_mux_match,
162 },
163};
164module_platform_driver(gpio_sbu_mux_driver);
165
166MODULE_DESCRIPTION("GPIO based SBU mux driver");
167MODULE_LICENSE("GPL");
168

source code of linux/drivers/usb/typec/mux/gpio-sbu-mux.c