1 // SPDX-License-Identifier: GPL-2.0
2 // ChromeOS Embedded Controller extcon
3 //
4 // Copyright (C) 2017 Google, Inc.
5 // Author: Benson Leung <bleung@chromium.org>
6 
7 #include <linux/extcon-provider.h>
8 #include <linux/kernel.h>
9 #include <linux/mfd/cros_ec.h>
10 #include <linux/module.h>
11 #include <linux/notifier.h>
12 #include <linux/of.h>
13 #include <linux/platform_device.h>
14 #include <linux/slab.h>
15 #include <linux/sched.h>
16 
17 struct cros_ec_extcon_info {
18 	struct device *dev;
19 	struct extcon_dev *edev;
20 
21 	int port_id;
22 
23 	struct cros_ec_device *ec;
24 
25 	struct notifier_block notifier;
26 
27 	unsigned int dr; /* data role */
28 	bool pr; /* power role (true if VBUS enabled) */
29 	bool dp; /* DisplayPort enabled */
30 	bool mux; /* SuperSpeed (usb3) enabled */
31 	unsigned int power_type;
32 };
33 
34 static const unsigned int usb_type_c_cable[] = {
35 	EXTCON_USB,
36 	EXTCON_USB_HOST,
37 	EXTCON_DISP_DP,
38 	EXTCON_NONE,
39 };
40 
41 enum usb_data_roles {
42 	DR_NONE,
43 	DR_HOST,
44 	DR_DEVICE,
45 };
46 
47 /**
48  * cros_ec_pd_command() - Send a command to the EC.
49  * @info: pointer to struct cros_ec_extcon_info
50  * @command: EC command
51  * @version: EC command version
52  * @outdata: EC command output data
53  * @outsize: Size of outdata
54  * @indata: EC command input data
55  * @insize: Size of indata
56  *
57  * Return: 0 on success, <0 on failure.
58  */
59 static int cros_ec_pd_command(struct cros_ec_extcon_info *info,
60 			      unsigned int command,
61 			      unsigned int version,
62 			      void *outdata,
63 			      unsigned int outsize,
64 			      void *indata,
65 			      unsigned int insize)
66 {
67 	struct cros_ec_command *msg;
68 	int ret;
69 
70 	msg = kzalloc(sizeof(*msg) + max(outsize, insize), GFP_KERNEL);
71 	if (!msg)
72 		return -ENOMEM;
73 
74 	msg->version = version;
75 	msg->command = command;
76 	msg->outsize = outsize;
77 	msg->insize = insize;
78 
79 	if (outsize)
80 		memcpy(msg->data, outdata, outsize);
81 
82 	ret = cros_ec_cmd_xfer_status(info->ec, msg);
83 	if (ret >= 0 && insize)
84 		memcpy(indata, msg->data, insize);
85 
86 	kfree(msg);
87 	return ret;
88 }
89 
90 /**
91  * cros_ec_usb_get_power_type() - Get power type info about PD device attached
92  * to given port.
93  * @info: pointer to struct cros_ec_extcon_info
94  *
95  * Return: power type on success, <0 on failure.
96  */
97 static int cros_ec_usb_get_power_type(struct cros_ec_extcon_info *info)
98 {
99 	struct ec_params_usb_pd_power_info req;
100 	struct ec_response_usb_pd_power_info resp;
101 	int ret;
102 
103 	req.port = info->port_id;
104 	ret = cros_ec_pd_command(info, EC_CMD_USB_PD_POWER_INFO, 0,
105 				 &req, sizeof(req), &resp, sizeof(resp));
106 	if (ret < 0)
107 		return ret;
108 
109 	return resp.type;
110 }
111 
112 /**
113  * cros_ec_usb_get_pd_mux_state() - Get PD mux state for given port.
114  * @info: pointer to struct cros_ec_extcon_info
115  *
116  * Return: PD mux state on success, <0 on failure.
117  */
118 static int cros_ec_usb_get_pd_mux_state(struct cros_ec_extcon_info *info)
119 {
120 	struct ec_params_usb_pd_mux_info req;
121 	struct ec_response_usb_pd_mux_info resp;
122 	int ret;
123 
124 	req.port = info->port_id;
125 	ret = cros_ec_pd_command(info, EC_CMD_USB_PD_MUX_INFO, 0,
126 				 &req, sizeof(req),
127 				 &resp, sizeof(resp));
128 	if (ret < 0)
129 		return ret;
130 
131 	return resp.flags;
132 }
133 
134 /**
135  * cros_ec_usb_get_role() - Get role info about possible PD device attached to a
136  * given port.
137  * @info: pointer to struct cros_ec_extcon_info
138  * @polarity: pointer to cable polarity (return value)
139  *
140  * Return: role info on success, -ENOTCONN if no cable is connected, <0 on
141  * failure.
142  */
143 static int cros_ec_usb_get_role(struct cros_ec_extcon_info *info,
144 				bool *polarity)
145 {
146 	struct ec_params_usb_pd_control pd_control;
147 	struct ec_response_usb_pd_control_v1 resp;
148 	int ret;
149 
150 	pd_control.port = info->port_id;
151 	pd_control.role = USB_PD_CTRL_ROLE_NO_CHANGE;
152 	pd_control.mux = USB_PD_CTRL_MUX_NO_CHANGE;
153 	pd_control.swap = USB_PD_CTRL_SWAP_NONE;
154 	ret = cros_ec_pd_command(info, EC_CMD_USB_PD_CONTROL, 1,
155 				 &pd_control, sizeof(pd_control),
156 				 &resp, sizeof(resp));
157 	if (ret < 0)
158 		return ret;
159 
160 	if (!(resp.enabled & PD_CTRL_RESP_ENABLED_CONNECTED))
161 		return -ENOTCONN;
162 
163 	*polarity = resp.polarity;
164 
165 	return resp.role;
166 }
167 
168 /**
169  * cros_ec_pd_get_num_ports() - Get number of EC charge ports.
170  * @info: pointer to struct cros_ec_extcon_info
171  *
172  * Return: number of ports on success, <0 on failure.
173  */
174 static int cros_ec_pd_get_num_ports(struct cros_ec_extcon_info *info)
175 {
176 	struct ec_response_usb_pd_ports resp;
177 	int ret;
178 
179 	ret = cros_ec_pd_command(info, EC_CMD_USB_PD_PORTS,
180 				 0, NULL, 0, &resp, sizeof(resp));
181 	if (ret < 0)
182 		return ret;
183 
184 	return resp.num_ports;
185 }
186 
187 static const char *cros_ec_usb_role_string(unsigned int role)
188 {
189 	return role == DR_NONE ? "DISCONNECTED" :
190 		(role == DR_HOST ? "DFP" : "UFP");
191 }
192 
193 static const char *cros_ec_usb_power_type_string(unsigned int type)
194 {
195 	switch (type) {
196 	case USB_CHG_TYPE_NONE:
197 		return "USB_CHG_TYPE_NONE";
198 	case USB_CHG_TYPE_PD:
199 		return "USB_CHG_TYPE_PD";
200 	case USB_CHG_TYPE_PROPRIETARY:
201 		return "USB_CHG_TYPE_PROPRIETARY";
202 	case USB_CHG_TYPE_C:
203 		return "USB_CHG_TYPE_C";
204 	case USB_CHG_TYPE_BC12_DCP:
205 		return "USB_CHG_TYPE_BC12_DCP";
206 	case USB_CHG_TYPE_BC12_CDP:
207 		return "USB_CHG_TYPE_BC12_CDP";
208 	case USB_CHG_TYPE_BC12_SDP:
209 		return "USB_CHG_TYPE_BC12_SDP";
210 	case USB_CHG_TYPE_OTHER:
211 		return "USB_CHG_TYPE_OTHER";
212 	case USB_CHG_TYPE_VBUS:
213 		return "USB_CHG_TYPE_VBUS";
214 	case USB_CHG_TYPE_UNKNOWN:
215 		return "USB_CHG_TYPE_UNKNOWN";
216 	default:
217 		return "USB_CHG_TYPE_UNKNOWN";
218 	}
219 }
220 
221 static bool cros_ec_usb_power_type_is_wall_wart(unsigned int type,
222 						unsigned int role)
223 {
224 	switch (type) {
225 	/* FIXME : Guppy, Donnettes, and other chargers will be miscategorized
226 	 * because they identify with USB_CHG_TYPE_C, but we can't return true
227 	 * here from that code because that breaks Suzy-Q and other kinds of
228 	 * USB Type-C cables and peripherals.
229 	 */
230 	case USB_CHG_TYPE_PROPRIETARY:
231 	case USB_CHG_TYPE_BC12_DCP:
232 		return true;
233 	case USB_CHG_TYPE_PD:
234 	case USB_CHG_TYPE_C:
235 	case USB_CHG_TYPE_BC12_CDP:
236 	case USB_CHG_TYPE_BC12_SDP:
237 	case USB_CHG_TYPE_OTHER:
238 	case USB_CHG_TYPE_VBUS:
239 	case USB_CHG_TYPE_UNKNOWN:
240 	case USB_CHG_TYPE_NONE:
241 	default:
242 		return false;
243 	}
244 }
245 
246 static int extcon_cros_ec_detect_cable(struct cros_ec_extcon_info *info,
247 				       bool force)
248 {
249 	struct device *dev = info->dev;
250 	int role, power_type;
251 	unsigned int dr = DR_NONE;
252 	bool pr = false;
253 	bool polarity = false;
254 	bool dp = false;
255 	bool mux = false;
256 	bool hpd = false;
257 
258 	power_type = cros_ec_usb_get_power_type(info);
259 	if (power_type < 0) {
260 		dev_err(dev, "failed getting power type err = %d\n",
261 			power_type);
262 		return power_type;
263 	}
264 
265 	role = cros_ec_usb_get_role(info, &polarity);
266 	if (role < 0) {
267 		if (role != -ENOTCONN) {
268 			dev_err(dev, "failed getting role err = %d\n", role);
269 			return role;
270 		}
271 		dev_dbg(dev, "disconnected\n");
272 	} else {
273 		int pd_mux_state;
274 
275 		dr = (role & PD_CTRL_RESP_ROLE_DATA) ? DR_HOST : DR_DEVICE;
276 		pr = (role & PD_CTRL_RESP_ROLE_POWER);
277 		pd_mux_state = cros_ec_usb_get_pd_mux_state(info);
278 		if (pd_mux_state < 0)
279 			pd_mux_state = USB_PD_MUX_USB_ENABLED;
280 
281 		dp = pd_mux_state & USB_PD_MUX_DP_ENABLED;
282 		mux = pd_mux_state & USB_PD_MUX_USB_ENABLED;
283 		hpd = pd_mux_state & USB_PD_MUX_HPD_IRQ;
284 
285 		dev_dbg(dev,
286 			"connected role 0x%x pwr type %d dr %d pr %d pol %d mux %d dp %d hpd %d\n",
287 			role, power_type, dr, pr, polarity, mux, dp, hpd);
288 	}
289 
290 	/*
291 	 * When there is no USB host (e.g. USB PD charger),
292 	 * we are not really a UFP for the AP.
293 	 */
294 	if (dr == DR_DEVICE &&
295 	    cros_ec_usb_power_type_is_wall_wart(power_type, role))
296 		dr = DR_NONE;
297 
298 	if (force || info->dr != dr || info->pr != pr || info->dp != dp ||
299 	    info->mux != mux || info->power_type != power_type) {
300 		bool host_connected = false, device_connected = false;
301 
302 		dev_dbg(dev, "Type/Role switch! type = %s role = %s\n",
303 			cros_ec_usb_power_type_string(power_type),
304 			cros_ec_usb_role_string(dr));
305 		info->dr = dr;
306 		info->pr = pr;
307 		info->dp = dp;
308 		info->mux = mux;
309 		info->power_type = power_type;
310 
311 		if (dr == DR_DEVICE)
312 			device_connected = true;
313 		else if (dr == DR_HOST)
314 			host_connected = true;
315 
316 		extcon_set_state(info->edev, EXTCON_USB, device_connected);
317 		extcon_set_state(info->edev, EXTCON_USB_HOST, host_connected);
318 		extcon_set_state(info->edev, EXTCON_DISP_DP, dp);
319 		extcon_set_property(info->edev, EXTCON_USB,
320 				    EXTCON_PROP_USB_VBUS,
321 				    (union extcon_property_value)(int)pr);
322 		extcon_set_property(info->edev, EXTCON_USB_HOST,
323 				    EXTCON_PROP_USB_VBUS,
324 				    (union extcon_property_value)(int)pr);
325 		extcon_set_property(info->edev, EXTCON_USB,
326 				    EXTCON_PROP_USB_TYPEC_POLARITY,
327 				    (union extcon_property_value)(int)polarity);
328 		extcon_set_property(info->edev, EXTCON_USB_HOST,
329 				    EXTCON_PROP_USB_TYPEC_POLARITY,
330 				    (union extcon_property_value)(int)polarity);
331 		extcon_set_property(info->edev, EXTCON_DISP_DP,
332 				    EXTCON_PROP_USB_TYPEC_POLARITY,
333 				    (union extcon_property_value)(int)polarity);
334 		extcon_set_property(info->edev, EXTCON_USB,
335 				    EXTCON_PROP_USB_SS,
336 				    (union extcon_property_value)(int)mux);
337 		extcon_set_property(info->edev, EXTCON_USB_HOST,
338 				    EXTCON_PROP_USB_SS,
339 				    (union extcon_property_value)(int)mux);
340 		extcon_set_property(info->edev, EXTCON_DISP_DP,
341 				    EXTCON_PROP_USB_SS,
342 				    (union extcon_property_value)(int)mux);
343 		extcon_set_property(info->edev, EXTCON_DISP_DP,
344 				    EXTCON_PROP_DISP_HPD,
345 				    (union extcon_property_value)(int)hpd);
346 
347 		extcon_sync(info->edev, EXTCON_USB);
348 		extcon_sync(info->edev, EXTCON_USB_HOST);
349 		extcon_sync(info->edev, EXTCON_DISP_DP);
350 
351 	} else if (hpd) {
352 		extcon_set_property(info->edev, EXTCON_DISP_DP,
353 				    EXTCON_PROP_DISP_HPD,
354 				    (union extcon_property_value)(int)hpd);
355 		extcon_sync(info->edev, EXTCON_DISP_DP);
356 	}
357 
358 	return 0;
359 }
360 
361 static int extcon_cros_ec_event(struct notifier_block *nb,
362 				unsigned long queued_during_suspend,
363 				void *_notify)
364 {
365 	struct cros_ec_extcon_info *info;
366 	struct cros_ec_device *ec;
367 	u32 host_event;
368 
369 	info = container_of(nb, struct cros_ec_extcon_info, notifier);
370 	ec = info->ec;
371 
372 	host_event = cros_ec_get_host_event(ec);
373 	if (host_event & (EC_HOST_EVENT_MASK(EC_HOST_EVENT_PD_MCU) |
374 			  EC_HOST_EVENT_MASK(EC_HOST_EVENT_USB_MUX))) {
375 		extcon_cros_ec_detect_cable(info, false);
376 		return NOTIFY_OK;
377 	}
378 
379 	return NOTIFY_DONE;
380 }
381 
382 static int extcon_cros_ec_probe(struct platform_device *pdev)
383 {
384 	struct cros_ec_extcon_info *info;
385 	struct cros_ec_device *ec = dev_get_drvdata(pdev->dev.parent);
386 	struct device *dev = &pdev->dev;
387 	struct device_node *np = dev->of_node;
388 	int numports, ret;
389 
390 	info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
391 	if (!info)
392 		return -ENOMEM;
393 
394 	info->dev = dev;
395 	info->ec = ec;
396 
397 	if (np) {
398 		u32 port;
399 
400 		ret = of_property_read_u32(np, "google,usb-port-id", &port);
401 		if (ret < 0) {
402 			dev_err(dev, "Missing google,usb-port-id property\n");
403 			return ret;
404 		}
405 		info->port_id = port;
406 	} else {
407 		info->port_id = pdev->id;
408 	}
409 
410 	numports = cros_ec_pd_get_num_ports(info);
411 	if (numports < 0) {
412 		dev_err(dev, "failed getting number of ports! ret = %d\n",
413 			numports);
414 		return numports;
415 	}
416 
417 	if (info->port_id >= numports) {
418 		dev_err(dev, "This system only supports %d ports\n", numports);
419 		return -ENODEV;
420 	}
421 
422 	info->edev = devm_extcon_dev_allocate(dev, usb_type_c_cable);
423 	if (IS_ERR(info->edev)) {
424 		dev_err(dev, "failed to allocate extcon device\n");
425 		return -ENOMEM;
426 	}
427 
428 	ret = devm_extcon_dev_register(dev, info->edev);
429 	if (ret < 0) {
430 		dev_err(dev, "failed to register extcon device\n");
431 		return ret;
432 	}
433 
434 	extcon_set_property_capability(info->edev, EXTCON_USB,
435 				       EXTCON_PROP_USB_VBUS);
436 	extcon_set_property_capability(info->edev, EXTCON_USB_HOST,
437 				       EXTCON_PROP_USB_VBUS);
438 	extcon_set_property_capability(info->edev, EXTCON_USB,
439 				       EXTCON_PROP_USB_TYPEC_POLARITY);
440 	extcon_set_property_capability(info->edev, EXTCON_USB_HOST,
441 				       EXTCON_PROP_USB_TYPEC_POLARITY);
442 	extcon_set_property_capability(info->edev, EXTCON_DISP_DP,
443 				       EXTCON_PROP_USB_TYPEC_POLARITY);
444 	extcon_set_property_capability(info->edev, EXTCON_USB,
445 				       EXTCON_PROP_USB_SS);
446 	extcon_set_property_capability(info->edev, EXTCON_USB_HOST,
447 				       EXTCON_PROP_USB_SS);
448 	extcon_set_property_capability(info->edev, EXTCON_DISP_DP,
449 				       EXTCON_PROP_USB_SS);
450 	extcon_set_property_capability(info->edev, EXTCON_DISP_DP,
451 				       EXTCON_PROP_DISP_HPD);
452 
453 	info->dr = DR_NONE;
454 	info->pr = false;
455 
456 	platform_set_drvdata(pdev, info);
457 
458 	/* Get PD events from the EC */
459 	info->notifier.notifier_call = extcon_cros_ec_event;
460 	ret = blocking_notifier_chain_register(&info->ec->event_notifier,
461 					       &info->notifier);
462 	if (ret < 0) {
463 		dev_err(dev, "failed to register notifier\n");
464 		return ret;
465 	}
466 
467 	/* Perform initial detection */
468 	ret = extcon_cros_ec_detect_cable(info, true);
469 	if (ret < 0) {
470 		dev_err(dev, "failed to detect initial cable state\n");
471 		goto unregister_notifier;
472 	}
473 
474 	return 0;
475 
476 unregister_notifier:
477 	blocking_notifier_chain_unregister(&info->ec->event_notifier,
478 					   &info->notifier);
479 	return ret;
480 }
481 
482 static int extcon_cros_ec_remove(struct platform_device *pdev)
483 {
484 	struct cros_ec_extcon_info *info = platform_get_drvdata(pdev);
485 
486 	blocking_notifier_chain_unregister(&info->ec->event_notifier,
487 					   &info->notifier);
488 
489 	return 0;
490 }
491 
492 #ifdef CONFIG_PM_SLEEP
493 static int extcon_cros_ec_suspend(struct device *dev)
494 {
495 	return 0;
496 }
497 
498 static int extcon_cros_ec_resume(struct device *dev)
499 {
500 	int ret;
501 	struct cros_ec_extcon_info *info = dev_get_drvdata(dev);
502 
503 	ret = extcon_cros_ec_detect_cable(info, true);
504 	if (ret < 0)
505 		dev_err(dev, "failed to detect cable state on resume\n");
506 
507 	return 0;
508 }
509 
510 static const struct dev_pm_ops extcon_cros_ec_dev_pm_ops = {
511 	SET_SYSTEM_SLEEP_PM_OPS(extcon_cros_ec_suspend, extcon_cros_ec_resume)
512 };
513 
514 #define DEV_PM_OPS	(&extcon_cros_ec_dev_pm_ops)
515 #else
516 #define DEV_PM_OPS	NULL
517 #endif /* CONFIG_PM_SLEEP */
518 
519 #ifdef CONFIG_OF
520 static const struct of_device_id extcon_cros_ec_of_match[] = {
521 	{ .compatible = "google,extcon-usbc-cros-ec" },
522 	{ /* sentinel */ }
523 };
524 MODULE_DEVICE_TABLE(of, extcon_cros_ec_of_match);
525 #endif /* CONFIG_OF */
526 
527 static struct platform_driver extcon_cros_ec_driver = {
528 	.driver = {
529 		.name  = "extcon-usbc-cros-ec",
530 		.of_match_table = of_match_ptr(extcon_cros_ec_of_match),
531 		.pm = DEV_PM_OPS,
532 	},
533 	.remove  = extcon_cros_ec_remove,
534 	.probe   = extcon_cros_ec_probe,
535 };
536 
537 module_platform_driver(extcon_cros_ec_driver);
538 
539 MODULE_DESCRIPTION("ChromeOS Embedded Controller extcon driver");
540 MODULE_AUTHOR("Benson Leung <bleung@chromium.org>");
541 MODULE_LICENSE("GPL v2");
542