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(sbu_mux->enable_gpio, enabled);
52
53	if (swapped != sbu_mux->swapped)
54		gpiod_set_value(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
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(sbu_mux->enable_gpio, sbu_mux->enabled);
86
87	mutex_unlock(&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, 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, "enable", GPIOD_OUT_LOW);
106	if (IS_ERR(sbu_mux->enable_gpio))
107		return dev_err_probe(dev, PTR_ERR(sbu_mux->enable_gpio),
108				     "unable to acquire enable gpio\n");
109
110	sbu_mux->select_gpio = devm_gpiod_get(dev, "select", GPIOD_OUT_LOW);
111	if (IS_ERR(sbu_mux->select_gpio))
112		return dev_err_probe(dev, PTR_ERR(sbu_mux->select_gpio),
113				     "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(dev, &sw_desc);
120	if (IS_ERR(sbu_mux->sw))
121		return dev_err_probe(dev, PTR_ERR(sbu_mux->sw),
122				     "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(dev, &mux_desc);
129	if (IS_ERR(sbu_mux->mux)) {
130		typec_switch_unregister(sbu_mux->sw);
131		return dev_err_probe(dev, PTR_ERR(sbu_mux->mux),
132				     "failed to register typec mux\n");
133	}
134
135	platform_set_drvdata(pdev, 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(sbu_mux->enable_gpio, 0);
145
146	typec_mux_unregister(sbu_mux->mux);
147	typec_switch_unregister(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