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/module.h>
10 #include <linux/notifier.h>
11 #include <linux/of.h>
12 #include <linux/platform_data/cros_ec_commands.h>
13 #include <linux/platform_data/cros_ec_proto.h>
14 #include <linux/platform_device.h>
15 #include <linux/slab.h>
16 #include <linux/sched.h>
17 
18 struct cros_ec_extcon_info {
19 	struct device *dev;
20 	struct extcon_dev *edev;
21 
22 	int port_id;
23 
24 	struct cros_ec_device *ec;
25 
26 	struct notifier_block notifier;
27 
28 	unsigned int dr; /* data role */
29 	bool pr; /* power role (true if VBUS enabled) */
30 	bool dp; /* DisplayPort enabled */
31 	bool mux; /* SuperSpeed (usb3) enabled */
32 	unsigned int power_type;
33 };
34 
35 static const unsigned int usb_type_c_cable[] = {
36 	EXTCON_USB,
37 	EXTCON_USB_HOST,
38 	EXTCON_DISP_DP,
39 	EXTCON_NONE,
40 };
41 
42 enum usb_data_roles {
43 	DR_NONE,
44 	DR_HOST,
45 	DR_DEVICE,
46 };
47 
48 /**
49  * cros_ec_pd_command() - Send a command to the EC.
50  * @info: pointer to struct cros_ec_extcon_info
51  * @command: EC command
52  * @version: EC command version
53  * @outdata: EC command output data
54  * @outsize: Size of outdata
55  * @indata: EC command input data
56  * @insize: Size of indata
57  *
58  * Return: 0 on success, <0 on failure.
59  */
60 static int cros_ec_pd_command(struct cros_ec_extcon_info *info,
61 			      unsigned int command,
62 			      unsigned int version,
63 			      void *outdata,
64 			      unsigned int outsize,
65 			      void *indata,
66 			      unsigned int insize)
67 {
68 	struct cros_ec_command *msg;
69 	int ret;
70 
71 	msg = kzalloc(struct_size(msg, data, max(outsize, insize)), GFP_KERNEL);
72 	if (!msg)
73 		return -ENOMEM;
74 
75 	msg->version = version;
76 	msg->command = command;
77 	msg->outsize = outsize;
78 	msg->insize = insize;
79 
80 	if (outsize)
81 		memcpy(msg->data, outdata, outsize);
82 
83 	ret = cros_ec_cmd_xfer_status(info->ec, msg);
84 	if (ret >= 0 && insize)
85 		memcpy(indata, msg->data, insize);
86 
87 	kfree(msg);
88 	return ret;
89 }
90 
91 /**
92  * cros_ec_usb_get_power_type() - Get power type info about PD device attached
93  * to given port.
94  * @info: pointer to struct cros_ec_extcon_info
95  *
96  * Return: power type on success, <0 on failure.
97  */
98 static int cros_ec_usb_get_power_type(struct cros_ec_extcon_info *info)
99 {
100 	struct ec_params_usb_pd_power_info req;
101 	struct ec_response_usb_pd_power_info resp;
102 	int ret;
103 
104 	req.port = info->port_id;
105 	ret = cros_ec_pd_command(info, EC_CMD_USB_PD_POWER_INFO, 0,
106 				 &req, sizeof(req), &resp, sizeof(resp));
107 	if (ret < 0)
108 		return ret;
109 
110 	return resp.type;
111 }
112 
113 /**
114  * cros_ec_usb_get_pd_mux_state() - Get PD mux state for given port.
115  * @info: pointer to struct cros_ec_extcon_info
116  *
117  * Return: PD mux state on success, <0 on failure.
118  */
119 static int cros_ec_usb_get_pd_mux_state(struct cros_ec_extcon_info *info)
120 {
121 	struct ec_params_usb_pd_mux_info req;
122 	struct ec_response_usb_pd_mux_info resp;
123 	int ret;
124 
125 	req.port = info->port_id;
126 	ret = cros_ec_pd_command(info, EC_CMD_USB_PD_MUX_INFO, 0,
127 				 &req, sizeof(req),
128 				 &resp, sizeof(resp));
129 	if (ret < 0)
130 		return ret;
131 
132 	return resp.flags;
133 }
134 
135 /**
136  * cros_ec_usb_get_role() - Get role info about possible PD device attached to a
137  * given port.
138  * @info: pointer to struct cros_ec_extcon_info
139  * @polarity: pointer to cable polarity (return value)
140  *
141  * Return: role info on success, -ENOTCONN if no cable is connected, <0 on
142  * failure.
143  */
144 static int cros_ec_usb_get_role(struct cros_ec_extcon_info *info,
145 				bool *polarity)
146 {
147 	struct ec_params_usb_pd_control pd_control;
148 	struct ec_response_usb_pd_control_v1 resp;
149 	int ret;
150 
151 	pd_control.port = info->port_id;
152 	pd_control.role = USB_PD_CTRL_ROLE_NO_CHANGE;
153 	pd_control.mux = USB_PD_CTRL_MUX_NO_CHANGE;
154 	pd_control.swap = USB_PD_CTRL_SWAP_NONE;
155 	ret = cros_ec_pd_command(info, EC_CMD_USB_PD_CONTROL, 1,
156 				 &pd_control, sizeof(pd_control),
157 				 &resp, sizeof(resp));
158 	if (ret < 0)
159 		return ret;
160 
161 	if (!(resp.enabled & PD_CTRL_RESP_ENABLED_CONNECTED))
162 		return -ENOTCONN;
163 
164 	*polarity = resp.polarity;
165 
166 	return resp.role;
167 }
168 
169 /**
170  * cros_ec_pd_get_num_ports() - Get number of EC charge ports.
171  * @info: pointer to struct cros_ec_extcon_info
172  *
173  * Return: number of ports on success, <0 on failure.
174  */
175 static int cros_ec_pd_get_num_ports(struct cros_ec_extcon_info *info)
176 {
177 	struct ec_response_usb_pd_ports resp;
178 	int ret;
179 
180 	ret = cros_ec_pd_command(info, EC_CMD_USB_PD_PORTS,
181 				 0, NULL, 0, &resp, sizeof(resp));
182 	if (ret < 0)
183 		return ret;
184 
185 	return resp.num_ports;
186 }
187 
188 static const char *cros_ec_usb_role_string(unsigned int role)
189 {
190 	return role == DR_NONE ? "DISCONNECTED" :
191 		(role == DR_HOST ? "DFP" : "UFP");
192 }
193 
194 static const char *cros_ec_usb_power_type_string(unsigned int type)
195 {
196 	switch (type) {
197 	case USB_CHG_TYPE_NONE:
198 		return "USB_CHG_TYPE_NONE";
199 	case USB_CHG_TYPE_PD:
200 		return "USB_CHG_TYPE_PD";
201 	case USB_CHG_TYPE_PROPRIETARY:
202 		return "USB_CHG_TYPE_PROPRIETARY";
203 	case USB_CHG_TYPE_C:
204 		return "USB_CHG_TYPE_C";
205 	case USB_CHG_TYPE_BC12_DCP:
206 		return "USB_CHG_TYPE_BC12_DCP";
207 	case USB_CHG_TYPE_BC12_CDP:
208 		return "USB_CHG_TYPE_BC12_CDP";
209 	case USB_CHG_TYPE_BC12_SDP:
210 		return "USB_CHG_TYPE_BC12_SDP";
211 	case USB_CHG_TYPE_OTHER:
212 		return "USB_CHG_TYPE_OTHER";
213 	case USB_CHG_TYPE_VBUS:
214 		return "USB_CHG_TYPE_VBUS";
215 	case USB_CHG_TYPE_UNKNOWN:
216 		return "USB_CHG_TYPE_UNKNOWN";
217 	default:
218 		return "USB_CHG_TYPE_UNKNOWN";
219 	}
220 }
221 
222 static bool cros_ec_usb_power_type_is_wall_wart(unsigned int type,
223 						unsigned int role)
224 {
225 	switch (type) {
226 	/* FIXME : Guppy, Donnettes, and other chargers will be miscategorized
227 	 * because they identify with USB_CHG_TYPE_C, but we can't return true
228 	 * here from that code because that breaks Suzy-Q and other kinds of
229 	 * USB Type-C cables and peripherals.
230 	 */
231 	case USB_CHG_TYPE_PROPRIETARY:
232 	case USB_CHG_TYPE_BC12_DCP:
233 		return true;
234 	case USB_CHG_TYPE_PD:
235 	case USB_CHG_TYPE_C:
236 	case USB_CHG_TYPE_BC12_CDP:
237 	case USB_CHG_TYPE_BC12_SDP:
238 	case USB_CHG_TYPE_OTHER:
239 	case USB_CHG_TYPE_VBUS:
240 	case USB_CHG_TYPE_UNKNOWN:
241 	case USB_CHG_TYPE_NONE:
242 	default:
243 		return false;
244 	}
245 }
246 
247 static int extcon_cros_ec_detect_cable(struct cros_ec_extcon_info *info,
248 				       bool force)
249 {
250 	struct device *dev = info->dev;
251 	int role, power_type;
252 	unsigned int dr = DR_NONE;
253 	bool pr = false;
254 	bool polarity = false;
255 	bool dp = false;
256 	bool mux = false;
257 	bool hpd = false;
258 
259 	power_type = cros_ec_usb_get_power_type(info);
260 	if (power_type < 0) {
261 		dev_err(dev, "failed getting power type err = %d\n",
262 			power_type);
263 		return power_type;
264 	}
265 
266 	role = cros_ec_usb_get_role(info, &polarity);
267 	if (role < 0) {
268 		if (role != -ENOTCONN) {
269 			dev_err(dev, "failed getting role err = %d\n", role);
270 			return role;
271 		}
272 		dev_dbg(dev, "disconnected\n");
273 	} else {
274 		int pd_mux_state;
275 
276 		dr = (role & PD_CTRL_RESP_ROLE_DATA) ? DR_HOST : DR_DEVICE;
277 		pr = (role & PD_CTRL_RESP_ROLE_POWER);
278 		pd_mux_state = cros_ec_usb_get_pd_mux_state(info);
279 		if (pd_mux_state < 0)
280 			pd_mux_state = USB_PD_MUX_USB_ENABLED;
281 
282 		dp = pd_mux_state & USB_PD_MUX_DP_ENABLED;
283 		mux = pd_mux_state & USB_PD_MUX_USB_ENABLED;
284 		hpd = pd_mux_state & USB_PD_MUX_HPD_IRQ;
285 
286 		dev_dbg(dev,
287 			"connected role 0x%x pwr type %d dr %d pr %d pol %d mux %d dp %d hpd %d\n",
288 			role, power_type, dr, pr, polarity, mux, dp, hpd);
289 	}
290 
291 	/*
292 	 * When there is no USB host (e.g. USB PD charger),
293 	 * we are not really a UFP for the AP.
294 	 */
295 	if (dr == DR_DEVICE &&
296 	    cros_ec_usb_power_type_is_wall_wart(power_type, role))
297 		dr = DR_NONE;
298 
299 	if (force || info->dr != dr || info->pr != pr || info->dp != dp ||
300 	    info->mux != mux || info->power_type != power_type) {
301 		bool host_connected = false, device_connected = false;
302 
303 		dev_dbg(dev, "Type/Role switch! type = %s role = %s\n",
304 			cros_ec_usb_power_type_string(power_type),
305 			cros_ec_usb_role_string(dr));
306 		info->dr = dr;
307 		info->pr = pr;
308 		info->dp = dp;
309 		info->mux = mux;
310 		info->power_type = power_type;
311 
312 		if (dr == DR_DEVICE)
313 			device_connected = true;
314 		else if (dr == DR_HOST)
315 			host_connected = true;
316 
317 		extcon_set_state(info->edev, EXTCON_USB, device_connected);
318 		extcon_set_state(info->edev, EXTCON_USB_HOST, host_connected);
319 		extcon_set_state(info->edev, EXTCON_DISP_DP, dp);
320 		extcon_set_property(info->edev, EXTCON_USB,
321 				    EXTCON_PROP_USB_VBUS,
322 				    (union extcon_property_value)(int)pr);
323 		extcon_set_property(info->edev, EXTCON_USB_HOST,
324 				    EXTCON_PROP_USB_VBUS,
325 				    (union extcon_property_value)(int)pr);
326 		extcon_set_property(info->edev, EXTCON_USB,
327 				    EXTCON_PROP_USB_TYPEC_POLARITY,
328 				    (union extcon_property_value)(int)polarity);
329 		extcon_set_property(info->edev, EXTCON_USB_HOST,
330 				    EXTCON_PROP_USB_TYPEC_POLARITY,
331 				    (union extcon_property_value)(int)polarity);
332 		extcon_set_property(info->edev, EXTCON_DISP_DP,
333 				    EXTCON_PROP_USB_TYPEC_POLARITY,
334 				    (union extcon_property_value)(int)polarity);
335 		extcon_set_property(info->edev, EXTCON_USB,
336 				    EXTCON_PROP_USB_SS,
337 				    (union extcon_property_value)(int)mux);
338 		extcon_set_property(info->edev, EXTCON_USB_HOST,
339 				    EXTCON_PROP_USB_SS,
340 				    (union extcon_property_value)(int)mux);
341 		extcon_set_property(info->edev, EXTCON_DISP_DP,
342 				    EXTCON_PROP_USB_SS,
343 				    (union extcon_property_value)(int)mux);
344 		extcon_set_property(info->edev, EXTCON_DISP_DP,
345 				    EXTCON_PROP_DISP_HPD,
346 				    (union extcon_property_value)(int)hpd);
347 
348 		extcon_sync(info->edev, EXTCON_USB);
349 		extcon_sync(info->edev, EXTCON_USB_HOST);
350 		extcon_sync(info->edev, EXTCON_DISP_DP);
351 
352 	} else if (hpd) {
353 		extcon_set_property(info->edev, EXTCON_DISP_DP,
354 				    EXTCON_PROP_DISP_HPD,
355 				    (union extcon_property_value)(int)hpd);
356 		extcon_sync(info->edev, EXTCON_DISP_DP);
357 	}
358 
359 	return 0;
360 }
361 
362 static int extcon_cros_ec_event(struct notifier_block *nb,
363 				unsigned long queued_during_suspend,
364 				void *_notify)
365 {
366 	struct cros_ec_extcon_info *info;
367 	struct cros_ec_device *ec;
368 	u32 host_event;
369 
370 	info = container_of(nb, struct cros_ec_extcon_info, notifier);
371 	ec = info->ec;
372 
373 	host_event = cros_ec_get_host_event(ec);
374 	if (host_event & (EC_HOST_EVENT_MASK(EC_HOST_EVENT_PD_MCU) |
375 			  EC_HOST_EVENT_MASK(EC_HOST_EVENT_USB_MUX))) {
376 		extcon_cros_ec_detect_cable(info, false);
377 		return NOTIFY_OK;
378 	}
379 
380 	return NOTIFY_DONE;
381 }
382 
383 static int extcon_cros_ec_probe(struct platform_device *pdev)
384 {
385 	struct cros_ec_extcon_info *info;
386 	struct cros_ec_device *ec = dev_get_drvdata(pdev->dev.parent);
387 	struct device *dev = &pdev->dev;
388 	struct device_node *np = dev->of_node;
389 	int numports, ret;
390 
391 	info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
392 	if (!info)
393 		return -ENOMEM;
394 
395 	info->dev = dev;
396 	info->ec = ec;
397 
398 	if (np) {
399 		u32 port;
400 
401 		ret = of_property_read_u32(np, "google,usb-port-id", &port);
402 		if (ret < 0) {
403 			dev_err(dev, "Missing google,usb-port-id property\n");
404 			return ret;
405 		}
406 		info->port_id = port;
407 	} else {
408 		info->port_id = pdev->id;
409 	}
410 
411 	numports = cros_ec_pd_get_num_ports(info);
412 	if (numports < 0) {
413 		dev_err(dev, "failed getting number of ports! ret = %d\n",
414 			numports);
415 		return numports;
416 	}
417 
418 	if (info->port_id >= numports) {
419 		dev_err(dev, "This system only supports %d ports\n", numports);
420 		return -ENODEV;
421 	}
422 
423 	info->edev = devm_extcon_dev_allocate(dev, usb_type_c_cable);
424 	if (IS_ERR(info->edev)) {
425 		dev_err(dev, "failed to allocate extcon device\n");
426 		return -ENOMEM;
427 	}
428 
429 	ret = devm_extcon_dev_register(dev, info->edev);
430 	if (ret < 0) {
431 		dev_err(dev, "failed to register extcon device\n");
432 		return ret;
433 	}
434 
435 	extcon_set_property_capability(info->edev, EXTCON_USB,
436 				       EXTCON_PROP_USB_VBUS);
437 	extcon_set_property_capability(info->edev, EXTCON_USB_HOST,
438 				       EXTCON_PROP_USB_VBUS);
439 	extcon_set_property_capability(info->edev, EXTCON_USB,
440 				       EXTCON_PROP_USB_TYPEC_POLARITY);
441 	extcon_set_property_capability(info->edev, EXTCON_USB_HOST,
442 				       EXTCON_PROP_USB_TYPEC_POLARITY);
443 	extcon_set_property_capability(info->edev, EXTCON_DISP_DP,
444 				       EXTCON_PROP_USB_TYPEC_POLARITY);
445 	extcon_set_property_capability(info->edev, EXTCON_USB,
446 				       EXTCON_PROP_USB_SS);
447 	extcon_set_property_capability(info->edev, EXTCON_USB_HOST,
448 				       EXTCON_PROP_USB_SS);
449 	extcon_set_property_capability(info->edev, EXTCON_DISP_DP,
450 				       EXTCON_PROP_USB_SS);
451 	extcon_set_property_capability(info->edev, EXTCON_DISP_DP,
452 				       EXTCON_PROP_DISP_HPD);
453 
454 	info->dr = DR_NONE;
455 	info->pr = false;
456 
457 	platform_set_drvdata(pdev, info);
458 
459 	/* Get PD events from the EC */
460 	info->notifier.notifier_call = extcon_cros_ec_event;
461 	ret = blocking_notifier_chain_register(&info->ec->event_notifier,
462 					       &info->notifier);
463 	if (ret < 0) {
464 		dev_err(dev, "failed to register notifier\n");
465 		return ret;
466 	}
467 
468 	/* Perform initial detection */
469 	ret = extcon_cros_ec_detect_cable(info, true);
470 	if (ret < 0) {
471 		dev_err(dev, "failed to detect initial cable state\n");
472 		goto unregister_notifier;
473 	}
474 
475 	return 0;
476 
477 unregister_notifier:
478 	blocking_notifier_chain_unregister(&info->ec->event_notifier,
479 					   &info->notifier);
480 	return ret;
481 }
482 
483 static int extcon_cros_ec_remove(struct platform_device *pdev)
484 {
485 	struct cros_ec_extcon_info *info = platform_get_drvdata(pdev);
486 
487 	blocking_notifier_chain_unregister(&info->ec->event_notifier,
488 					   &info->notifier);
489 
490 	return 0;
491 }
492 
493 #ifdef CONFIG_PM_SLEEP
494 static int extcon_cros_ec_suspend(struct device *dev)
495 {
496 	return 0;
497 }
498 
499 static int extcon_cros_ec_resume(struct device *dev)
500 {
501 	int ret;
502 	struct cros_ec_extcon_info *info = dev_get_drvdata(dev);
503 
504 	ret = extcon_cros_ec_detect_cable(info, true);
505 	if (ret < 0)
506 		dev_err(dev, "failed to detect cable state on resume\n");
507 
508 	return 0;
509 }
510 
511 static const struct dev_pm_ops extcon_cros_ec_dev_pm_ops = {
512 	SET_SYSTEM_SLEEP_PM_OPS(extcon_cros_ec_suspend, extcon_cros_ec_resume)
513 };
514 
515 #define DEV_PM_OPS	(&extcon_cros_ec_dev_pm_ops)
516 #else
517 #define DEV_PM_OPS	NULL
518 #endif /* CONFIG_PM_SLEEP */
519 
520 #ifdef CONFIG_OF
521 static const struct of_device_id extcon_cros_ec_of_match[] = {
522 	{ .compatible = "google,extcon-usbc-cros-ec" },
523 	{ /* sentinel */ }
524 };
525 MODULE_DEVICE_TABLE(of, extcon_cros_ec_of_match);
526 #endif /* CONFIG_OF */
527 
528 static struct platform_driver extcon_cros_ec_driver = {
529 	.driver = {
530 		.name  = "extcon-usbc-cros-ec",
531 		.of_match_table = of_match_ptr(extcon_cros_ec_of_match),
532 		.pm = DEV_PM_OPS,
533 	},
534 	.remove  = extcon_cros_ec_remove,
535 	.probe   = extcon_cros_ec_probe,
536 };
537 
538 module_platform_driver(extcon_cros_ec_driver);
539 
540 MODULE_DESCRIPTION("ChromeOS Embedded Controller extcon driver");
541 MODULE_AUTHOR("Benson Leung <bleung@chromium.org>");
542 MODULE_LICENSE("GPL v2");
543