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 | |
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(desc: sbu_mux->enable_gpio, value: enabled); |
52 | |
53 | if (swapped != sbu_mux->swapped) |
54 | gpiod_set_value_cansleep(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 | |
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(desc: sbu_mux->enable_gpio, value: sbu_mux->enabled); |
89 | |
90 | mutex_unlock(lock: &sbu_mux->lock); |
91 | |
92 | return 0; |
93 | } |
94 | |
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, size: 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, con_id: "enable" , |
109 | flags: GPIOD_OUT_LOW); |
110 | if (IS_ERR(ptr: sbu_mux->enable_gpio)) |
111 | return dev_err_probe(dev, err: PTR_ERR(ptr: sbu_mux->enable_gpio), |
112 | fmt: "unable to acquire enable gpio\n" ); |
113 | |
114 | sbu_mux->select_gpio = devm_gpiod_get(dev, con_id: "select" , flags: GPIOD_OUT_LOW); |
115 | if (IS_ERR(ptr: sbu_mux->select_gpio)) |
116 | return dev_err_probe(dev, err: PTR_ERR(ptr: sbu_mux->select_gpio), |
117 | fmt: "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(parent: dev, desc: &sw_desc); |
124 | if (IS_ERR(ptr: sbu_mux->sw)) |
125 | return dev_err_probe(dev, err: PTR_ERR(ptr: sbu_mux->sw), |
126 | fmt: "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(parent: dev, desc: &mux_desc); |
133 | if (IS_ERR(ptr: sbu_mux->mux)) { |
134 | typec_switch_unregister(sw: sbu_mux->sw); |
135 | return dev_err_probe(dev, err: PTR_ERR(ptr: sbu_mux->mux), |
136 | fmt: "failed to register typec mux\n" ); |
137 | } |
138 | |
139 | platform_set_drvdata(pdev, data: sbu_mux); |
140 | |
141 | return 0; |
142 | } |
143 | |
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(desc: sbu_mux->enable_gpio, value: 0); |
149 | |
150 | typec_mux_unregister(mux: sbu_mux->mux); |
151 | typec_switch_unregister(sw: 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 = 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 | |