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
14 struct 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
gpio_sbu_switch_set(struct typec_switch_dev * sw,enum typec_orientation orientation)26 static 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_cansleep(sbu_mux->enable_gpio, enabled);
52
53 if (swapped != sbu_mux->swapped)
54 gpiod_set_value_cansleep(sbu_mux->select_gpio, swapped);
55
56 sbu_mux->enabled = enabled;
57 sbu_mux->swapped = swapped;
58
59 mutex_unlock(&sbu_mux->lock);
60
61 return 0;
62 }
63
gpio_sbu_mux_set(struct typec_mux_dev * mux,struct typec_mux_state * state)64 static 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 if (!sbu_mux->enable_gpio)
70 return -EOPNOTSUPP;
71
72 mutex_lock(&sbu_mux->lock);
73
74 switch (state->mode) {
75 case TYPEC_STATE_SAFE:
76 case TYPEC_STATE_USB:
77 sbu_mux->enabled = false;
78 break;
79 case TYPEC_DP_STATE_C:
80 case TYPEC_DP_STATE_D:
81 case TYPEC_DP_STATE_E:
82 sbu_mux->enabled = true;
83 break;
84 default:
85 break;
86 }
87
88 gpiod_set_value_cansleep(sbu_mux->enable_gpio, sbu_mux->enabled);
89
90 mutex_unlock(&sbu_mux->lock);
91
92 return 0;
93 }
94
gpio_sbu_mux_probe(struct platform_device * pdev)95 static int gpio_sbu_mux_probe(struct platform_device *pdev)
96 {
97 struct typec_switch_desc sw_desc = { };
98 struct typec_mux_desc mux_desc = { };
99 struct device *dev = &pdev->dev;
100 struct gpio_sbu_mux *sbu_mux;
101
102 sbu_mux = devm_kzalloc(dev, sizeof(*sbu_mux), GFP_KERNEL);
103 if (!sbu_mux)
104 return -ENOMEM;
105
106 mutex_init(&sbu_mux->lock);
107
108 sbu_mux->enable_gpio = devm_gpiod_get_optional(dev, "enable",
109 GPIOD_OUT_LOW);
110 if (IS_ERR(sbu_mux->enable_gpio))
111 return dev_err_probe(dev, PTR_ERR(sbu_mux->enable_gpio),
112 "unable to acquire enable gpio\n");
113
114 sbu_mux->select_gpio = devm_gpiod_get(dev, "select", GPIOD_OUT_LOW);
115 if (IS_ERR(sbu_mux->select_gpio))
116 return dev_err_probe(dev, PTR_ERR(sbu_mux->select_gpio),
117 "unable to acquire select gpio\n");
118
119 sw_desc.drvdata = sbu_mux;
120 sw_desc.fwnode = dev_fwnode(dev);
121 sw_desc.set = gpio_sbu_switch_set;
122
123 sbu_mux->sw = typec_switch_register(dev, &sw_desc);
124 if (IS_ERR(sbu_mux->sw))
125 return dev_err_probe(dev, PTR_ERR(sbu_mux->sw),
126 "failed to register typec switch\n");
127
128 mux_desc.drvdata = sbu_mux;
129 mux_desc.fwnode = dev_fwnode(dev);
130 mux_desc.set = gpio_sbu_mux_set;
131
132 sbu_mux->mux = typec_mux_register(dev, &mux_desc);
133 if (IS_ERR(sbu_mux->mux)) {
134 typec_switch_unregister(sbu_mux->sw);
135 return dev_err_probe(dev, PTR_ERR(sbu_mux->mux),
136 "failed to register typec mux\n");
137 }
138
139 platform_set_drvdata(pdev, sbu_mux);
140
141 return 0;
142 }
143
gpio_sbu_mux_remove(struct platform_device * pdev)144 static void gpio_sbu_mux_remove(struct platform_device *pdev)
145 {
146 struct gpio_sbu_mux *sbu_mux = platform_get_drvdata(pdev);
147
148 gpiod_set_value_cansleep(sbu_mux->enable_gpio, 0);
149
150 typec_mux_unregister(sbu_mux->mux);
151 typec_switch_unregister(sbu_mux->sw);
152 }
153
154 static const struct of_device_id gpio_sbu_mux_match[] = {
155 { .compatible = "gpio-sbu-mux", },
156 {}
157 };
158 MODULE_DEVICE_TABLE(of, gpio_sbu_mux_match);
159
160 static struct platform_driver gpio_sbu_mux_driver = {
161 .probe = gpio_sbu_mux_probe,
162 .remove_new = gpio_sbu_mux_remove,
163 .driver = {
164 .name = "gpio_sbu_mux",
165 .of_match_table = gpio_sbu_mux_match,
166 },
167 };
168 module_platform_driver(gpio_sbu_mux_driver);
169
170 MODULE_DESCRIPTION("GPIO based SBU mux driver");
171 MODULE_LICENSE("GPL");
172