1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * USB GPIO Based Connection Detection Driver |
4 | * |
5 | * Copyright (C) 2019 MediaTek Inc. |
6 | * |
7 | * Author: Chunfeng Yun <chunfeng.yun@mediatek.com> |
8 | * |
9 | * Some code borrowed from drivers/extcon/extcon-usb-gpio.c |
10 | */ |
11 | |
12 | #include <linux/device.h> |
13 | #include <linux/gpio/consumer.h> |
14 | #include <linux/interrupt.h> |
15 | #include <linux/irq.h> |
16 | #include <linux/module.h> |
17 | #include <linux/of.h> |
18 | #include <linux/pinctrl/consumer.h> |
19 | #include <linux/platform_device.h> |
20 | #include <linux/power_supply.h> |
21 | #include <linux/regulator/consumer.h> |
22 | #include <linux/usb/role.h> |
23 | |
24 | #define USB_GPIO_DEB_MS 20 /* ms */ |
25 | #define USB_GPIO_DEB_US ((USB_GPIO_DEB_MS) * 1000) /* us */ |
26 | |
27 | #define USB_CONN_IRQF \ |
28 | (IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | IRQF_ONESHOT) |
29 | |
30 | struct usb_conn_info { |
31 | struct device *dev; |
32 | struct usb_role_switch *role_sw; |
33 | enum usb_role last_role; |
34 | struct regulator *vbus; |
35 | struct delayed_work dw_det; |
36 | unsigned long debounce_jiffies; |
37 | |
38 | struct gpio_desc *id_gpiod; |
39 | struct gpio_desc *vbus_gpiod; |
40 | int id_irq; |
41 | int vbus_irq; |
42 | |
43 | struct power_supply_desc desc; |
44 | struct power_supply *charger; |
45 | bool initial_detection; |
46 | }; |
47 | |
48 | /* |
49 | * "DEVICE" = VBUS and "HOST" = !ID, so we have: |
50 | * Both "DEVICE" and "HOST" can't be set as active at the same time |
51 | * so if "HOST" is active (i.e. ID is 0) we keep "DEVICE" inactive |
52 | * even if VBUS is on. |
53 | * |
54 | * Role | ID | VBUS |
55 | * ------------------------------------ |
56 | * [1] DEVICE | H | H |
57 | * [2] NONE | H | L |
58 | * [3] HOST | L | H |
59 | * [4] HOST | L | L |
60 | * |
61 | * In case we have only one of these signals: |
62 | * - VBUS only - we want to distinguish between [1] and [2], so ID is always 1 |
63 | * - ID only - we want to distinguish between [1] and [4], so VBUS = ID |
64 | */ |
65 | static void usb_conn_detect_cable(struct work_struct *work) |
66 | { |
67 | struct usb_conn_info *info; |
68 | enum usb_role role; |
69 | int id, vbus, ret; |
70 | |
71 | info = container_of(to_delayed_work(work), |
72 | struct usb_conn_info, dw_det); |
73 | |
74 | /* check ID and VBUS */ |
75 | id = info->id_gpiod ? |
76 | gpiod_get_value_cansleep(desc: info->id_gpiod) : 1; |
77 | vbus = info->vbus_gpiod ? |
78 | gpiod_get_value_cansleep(desc: info->vbus_gpiod) : id; |
79 | |
80 | if (!id) |
81 | role = USB_ROLE_HOST; |
82 | else if (vbus) |
83 | role = USB_ROLE_DEVICE; |
84 | else |
85 | role = USB_ROLE_NONE; |
86 | |
87 | dev_dbg(info->dev, "role %s -> %s, gpios: id %d, vbus %d\n" , |
88 | usb_role_string(info->last_role), usb_role_string(role), id, vbus); |
89 | |
90 | if (!info->initial_detection && info->last_role == role) { |
91 | dev_warn(info->dev, "repeated role: %s\n" , usb_role_string(role)); |
92 | return; |
93 | } |
94 | |
95 | info->initial_detection = false; |
96 | |
97 | if (info->last_role == USB_ROLE_HOST && info->vbus) |
98 | regulator_disable(regulator: info->vbus); |
99 | |
100 | ret = usb_role_switch_set_role(sw: info->role_sw, role); |
101 | if (ret) |
102 | dev_err(info->dev, "failed to set role: %d\n" , ret); |
103 | |
104 | if (role == USB_ROLE_HOST && info->vbus) { |
105 | ret = regulator_enable(regulator: info->vbus); |
106 | if (ret) |
107 | dev_err(info->dev, "enable vbus regulator failed\n" ); |
108 | } |
109 | |
110 | info->last_role = role; |
111 | |
112 | if (info->vbus) |
113 | dev_dbg(info->dev, "vbus regulator is %s\n" , |
114 | regulator_is_enabled(info->vbus) ? "enabled" : "disabled" ); |
115 | |
116 | power_supply_changed(psy: info->charger); |
117 | } |
118 | |
119 | static void usb_conn_queue_dwork(struct usb_conn_info *info, |
120 | unsigned long delay) |
121 | { |
122 | queue_delayed_work(wq: system_power_efficient_wq, dwork: &info->dw_det, delay); |
123 | } |
124 | |
125 | static irqreturn_t usb_conn_isr(int irq, void *dev_id) |
126 | { |
127 | struct usb_conn_info *info = dev_id; |
128 | |
129 | usb_conn_queue_dwork(info, delay: info->debounce_jiffies); |
130 | |
131 | return IRQ_HANDLED; |
132 | } |
133 | |
134 | static enum power_supply_property usb_charger_properties[] = { |
135 | POWER_SUPPLY_PROP_ONLINE, |
136 | }; |
137 | |
138 | static int usb_charger_get_property(struct power_supply *psy, |
139 | enum power_supply_property psp, |
140 | union power_supply_propval *val) |
141 | { |
142 | struct usb_conn_info *info = power_supply_get_drvdata(psy); |
143 | |
144 | switch (psp) { |
145 | case POWER_SUPPLY_PROP_ONLINE: |
146 | val->intval = info->last_role == USB_ROLE_DEVICE; |
147 | break; |
148 | default: |
149 | return -EINVAL; |
150 | } |
151 | |
152 | return 0; |
153 | } |
154 | |
155 | static int usb_conn_psy_register(struct usb_conn_info *info) |
156 | { |
157 | struct device *dev = info->dev; |
158 | struct power_supply_desc *desc = &info->desc; |
159 | struct power_supply_config cfg = { |
160 | .of_node = dev->of_node, |
161 | }; |
162 | |
163 | desc->name = "usb-charger" ; |
164 | desc->properties = usb_charger_properties; |
165 | desc->num_properties = ARRAY_SIZE(usb_charger_properties); |
166 | desc->get_property = usb_charger_get_property; |
167 | desc->type = POWER_SUPPLY_TYPE_USB; |
168 | cfg.drv_data = info; |
169 | |
170 | info->charger = devm_power_supply_register(parent: dev, desc, cfg: &cfg); |
171 | if (IS_ERR(ptr: info->charger)) |
172 | dev_err(dev, "Unable to register charger\n" ); |
173 | |
174 | return PTR_ERR_OR_ZERO(ptr: info->charger); |
175 | } |
176 | |
177 | static int usb_conn_probe(struct platform_device *pdev) |
178 | { |
179 | struct device *dev = &pdev->dev; |
180 | struct usb_conn_info *info; |
181 | int ret = 0; |
182 | |
183 | info = devm_kzalloc(dev, size: sizeof(*info), GFP_KERNEL); |
184 | if (!info) |
185 | return -ENOMEM; |
186 | |
187 | info->dev = dev; |
188 | info->id_gpiod = devm_gpiod_get_optional(dev, con_id: "id" , flags: GPIOD_IN); |
189 | if (IS_ERR(ptr: info->id_gpiod)) |
190 | return PTR_ERR(ptr: info->id_gpiod); |
191 | |
192 | info->vbus_gpiod = devm_gpiod_get_optional(dev, con_id: "vbus" , flags: GPIOD_IN); |
193 | if (IS_ERR(ptr: info->vbus_gpiod)) |
194 | return PTR_ERR(ptr: info->vbus_gpiod); |
195 | |
196 | if (!info->id_gpiod && !info->vbus_gpiod) { |
197 | dev_err(dev, "failed to get gpios\n" ); |
198 | return -ENODEV; |
199 | } |
200 | |
201 | if (info->id_gpiod) |
202 | ret = gpiod_set_debounce(desc: info->id_gpiod, USB_GPIO_DEB_US); |
203 | if (!ret && info->vbus_gpiod) |
204 | ret = gpiod_set_debounce(desc: info->vbus_gpiod, USB_GPIO_DEB_US); |
205 | if (ret < 0) |
206 | info->debounce_jiffies = msecs_to_jiffies(USB_GPIO_DEB_MS); |
207 | |
208 | INIT_DELAYED_WORK(&info->dw_det, usb_conn_detect_cable); |
209 | |
210 | info->vbus = devm_regulator_get_optional(dev, id: "vbus" ); |
211 | if (PTR_ERR(ptr: info->vbus) == -ENODEV) |
212 | info->vbus = NULL; |
213 | |
214 | if (IS_ERR(ptr: info->vbus)) |
215 | return dev_err_probe(dev, err: PTR_ERR(ptr: info->vbus), fmt: "failed to get vbus\n" ); |
216 | |
217 | info->role_sw = usb_role_switch_get(dev); |
218 | if (IS_ERR(ptr: info->role_sw)) |
219 | return dev_err_probe(dev, err: PTR_ERR(ptr: info->role_sw), |
220 | fmt: "failed to get role switch\n" ); |
221 | |
222 | ret = usb_conn_psy_register(info); |
223 | if (ret) |
224 | goto put_role_sw; |
225 | |
226 | if (info->id_gpiod) { |
227 | info->id_irq = gpiod_to_irq(desc: info->id_gpiod); |
228 | if (info->id_irq < 0) { |
229 | dev_err(dev, "failed to get ID IRQ\n" ); |
230 | ret = info->id_irq; |
231 | goto put_role_sw; |
232 | } |
233 | |
234 | ret = devm_request_threaded_irq(dev, irq: info->id_irq, NULL, |
235 | thread_fn: usb_conn_isr, USB_CONN_IRQF, |
236 | devname: pdev->name, dev_id: info); |
237 | if (ret < 0) { |
238 | dev_err(dev, "failed to request ID IRQ\n" ); |
239 | goto put_role_sw; |
240 | } |
241 | } |
242 | |
243 | if (info->vbus_gpiod) { |
244 | info->vbus_irq = gpiod_to_irq(desc: info->vbus_gpiod); |
245 | if (info->vbus_irq < 0) { |
246 | dev_err(dev, "failed to get VBUS IRQ\n" ); |
247 | ret = info->vbus_irq; |
248 | goto put_role_sw; |
249 | } |
250 | |
251 | ret = devm_request_threaded_irq(dev, irq: info->vbus_irq, NULL, |
252 | thread_fn: usb_conn_isr, USB_CONN_IRQF, |
253 | devname: pdev->name, dev_id: info); |
254 | if (ret < 0) { |
255 | dev_err(dev, "failed to request VBUS IRQ\n" ); |
256 | goto put_role_sw; |
257 | } |
258 | } |
259 | |
260 | platform_set_drvdata(pdev, data: info); |
261 | device_set_wakeup_capable(dev: &pdev->dev, capable: true); |
262 | |
263 | /* Perform initial detection */ |
264 | info->initial_detection = true; |
265 | usb_conn_queue_dwork(info, delay: 0); |
266 | |
267 | return 0; |
268 | |
269 | put_role_sw: |
270 | usb_role_switch_put(sw: info->role_sw); |
271 | return ret; |
272 | } |
273 | |
274 | static void usb_conn_remove(struct platform_device *pdev) |
275 | { |
276 | struct usb_conn_info *info = platform_get_drvdata(pdev); |
277 | |
278 | cancel_delayed_work_sync(dwork: &info->dw_det); |
279 | |
280 | if (info->last_role == USB_ROLE_HOST && info->vbus) |
281 | regulator_disable(regulator: info->vbus); |
282 | |
283 | usb_role_switch_put(sw: info->role_sw); |
284 | } |
285 | |
286 | static int __maybe_unused usb_conn_suspend(struct device *dev) |
287 | { |
288 | struct usb_conn_info *info = dev_get_drvdata(dev); |
289 | |
290 | if (device_may_wakeup(dev)) { |
291 | if (info->id_gpiod) |
292 | enable_irq_wake(irq: info->id_irq); |
293 | if (info->vbus_gpiod) |
294 | enable_irq_wake(irq: info->vbus_irq); |
295 | return 0; |
296 | } |
297 | |
298 | if (info->id_gpiod) |
299 | disable_irq(irq: info->id_irq); |
300 | if (info->vbus_gpiod) |
301 | disable_irq(irq: info->vbus_irq); |
302 | |
303 | pinctrl_pm_select_sleep_state(dev); |
304 | |
305 | return 0; |
306 | } |
307 | |
308 | static int __maybe_unused usb_conn_resume(struct device *dev) |
309 | { |
310 | struct usb_conn_info *info = dev_get_drvdata(dev); |
311 | |
312 | if (device_may_wakeup(dev)) { |
313 | if (info->id_gpiod) |
314 | disable_irq_wake(irq: info->id_irq); |
315 | if (info->vbus_gpiod) |
316 | disable_irq_wake(irq: info->vbus_irq); |
317 | return 0; |
318 | } |
319 | |
320 | pinctrl_pm_select_default_state(dev); |
321 | |
322 | if (info->id_gpiod) |
323 | enable_irq(irq: info->id_irq); |
324 | if (info->vbus_gpiod) |
325 | enable_irq(irq: info->vbus_irq); |
326 | |
327 | usb_conn_queue_dwork(info, delay: 0); |
328 | |
329 | return 0; |
330 | } |
331 | |
332 | static SIMPLE_DEV_PM_OPS(usb_conn_pm_ops, |
333 | usb_conn_suspend, usb_conn_resume); |
334 | |
335 | static const struct of_device_id usb_conn_dt_match[] = { |
336 | { .compatible = "gpio-usb-b-connector" , }, |
337 | { } |
338 | }; |
339 | MODULE_DEVICE_TABLE(of, usb_conn_dt_match); |
340 | |
341 | static struct platform_driver usb_conn_driver = { |
342 | .probe = usb_conn_probe, |
343 | .remove_new = usb_conn_remove, |
344 | .driver = { |
345 | .name = "usb-conn-gpio" , |
346 | .pm = &usb_conn_pm_ops, |
347 | .of_match_table = usb_conn_dt_match, |
348 | }, |
349 | }; |
350 | |
351 | module_platform_driver(usb_conn_driver); |
352 | |
353 | MODULE_AUTHOR("Chunfeng Yun <chunfeng.yun@mediatek.com>" ); |
354 | MODULE_DESCRIPTION("USB GPIO based connection detection driver" ); |
355 | MODULE_LICENSE("GPL v2" ); |
356 | |