xref: /linux/drivers/extcon/extcon-usbc-cros-ec.c (revision 3ad0876554cafa368f574d4d408468510543e9ff)
1 /**
2  * drivers/extcon/extcon-usbc-cros-ec - ChromeOS Embedded Controller extcon
3  *
4  * Copyright (C) 2017 Google, Inc
5  * Author: Benson Leung <bleung@chromium.org>
6  *
7  * This software is licensed under the terms of the GNU General Public
8  * License version 2, as published by the Free Software Foundation, and
9  * may be copied, distributed, and modified under those terms.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  */
16 
17 #include <linux/extcon-provider.h>
18 #include <linux/kernel.h>
19 #include <linux/mfd/cros_ec.h>
20 #include <linux/module.h>
21 #include <linux/notifier.h>
22 #include <linux/of.h>
23 #include <linux/platform_device.h>
24 #include <linux/slab.h>
25 #include <linux/sched.h>
26 
27 struct cros_ec_extcon_info {
28 	struct device *dev;
29 	struct extcon_dev *edev;
30 
31 	int port_id;
32 
33 	struct cros_ec_device *ec;
34 
35 	struct notifier_block notifier;
36 
37 	unsigned int dr; /* data role */
38 	bool pr; /* power role (true if VBUS enabled) */
39 	bool dp; /* DisplayPort enabled */
40 	bool mux; /* SuperSpeed (usb3) enabled */
41 	unsigned int power_type;
42 };
43 
44 static const unsigned int usb_type_c_cable[] = {
45 	EXTCON_USB,
46 	EXTCON_USB_HOST,
47 	EXTCON_DISP_DP,
48 	EXTCON_NONE,
49 };
50 
51 enum usb_data_roles {
52 	DR_NONE,
53 	DR_HOST,
54 	DR_DEVICE,
55 };
56 
57 /**
58  * cros_ec_pd_command() - Send a command to the EC.
59  * @info: pointer to struct cros_ec_extcon_info
60  * @command: EC command
61  * @version: EC command version
62  * @outdata: EC command output data
63  * @outsize: Size of outdata
64  * @indata: EC command input data
65  * @insize: Size of indata
66  *
67  * Return: 0 on success, <0 on failure.
68  */
69 static int cros_ec_pd_command(struct cros_ec_extcon_info *info,
70 			      unsigned int command,
71 			      unsigned int version,
72 			      void *outdata,
73 			      unsigned int outsize,
74 			      void *indata,
75 			      unsigned int insize)
76 {
77 	struct cros_ec_command *msg;
78 	int ret;
79 
80 	msg = kzalloc(sizeof(*msg) + max(outsize, insize), GFP_KERNEL);
81 	if (!msg)
82 		return -ENOMEM;
83 
84 	msg->version = version;
85 	msg->command = command;
86 	msg->outsize = outsize;
87 	msg->insize = insize;
88 
89 	if (outsize)
90 		memcpy(msg->data, outdata, outsize);
91 
92 	ret = cros_ec_cmd_xfer_status(info->ec, msg);
93 	if (ret >= 0 && insize)
94 		memcpy(indata, msg->data, insize);
95 
96 	kfree(msg);
97 	return ret;
98 }
99 
100 /**
101  * cros_ec_usb_get_power_type() - Get power type info about PD device attached
102  * to given port.
103  * @info: pointer to struct cros_ec_extcon_info
104  *
105  * Return: power type on success, <0 on failure.
106  */
107 static int cros_ec_usb_get_power_type(struct cros_ec_extcon_info *info)
108 {
109 	struct ec_params_usb_pd_power_info req;
110 	struct ec_response_usb_pd_power_info resp;
111 	int ret;
112 
113 	req.port = info->port_id;
114 	ret = cros_ec_pd_command(info, EC_CMD_USB_PD_POWER_INFO, 0,
115 				 &req, sizeof(req), &resp, sizeof(resp));
116 	if (ret < 0)
117 		return ret;
118 
119 	return resp.type;
120 }
121 
122 /**
123  * cros_ec_usb_get_pd_mux_state() - Get PD mux state for given port.
124  * @info: pointer to struct cros_ec_extcon_info
125  *
126  * Return: PD mux state on success, <0 on failure.
127  */
128 static int cros_ec_usb_get_pd_mux_state(struct cros_ec_extcon_info *info)
129 {
130 	struct ec_params_usb_pd_mux_info req;
131 	struct ec_response_usb_pd_mux_info resp;
132 	int ret;
133 
134 	req.port = info->port_id;
135 	ret = cros_ec_pd_command(info, EC_CMD_USB_PD_MUX_INFO, 0,
136 				 &req, sizeof(req),
137 				 &resp, sizeof(resp));
138 	if (ret < 0)
139 		return ret;
140 
141 	return resp.flags;
142 }
143 
144 /**
145  * cros_ec_usb_get_role() - Get role info about possible PD device attached to a
146  * given port.
147  * @info: pointer to struct cros_ec_extcon_info
148  * @polarity: pointer to cable polarity (return value)
149  *
150  * Return: role info on success, -ENOTCONN if no cable is connected, <0 on
151  * failure.
152  */
153 static int cros_ec_usb_get_role(struct cros_ec_extcon_info *info,
154 				bool *polarity)
155 {
156 	struct ec_params_usb_pd_control pd_control;
157 	struct ec_response_usb_pd_control_v1 resp;
158 	int ret;
159 
160 	pd_control.port = info->port_id;
161 	pd_control.role = USB_PD_CTRL_ROLE_NO_CHANGE;
162 	pd_control.mux = USB_PD_CTRL_MUX_NO_CHANGE;
163 	pd_control.swap = USB_PD_CTRL_SWAP_NONE;
164 	ret = cros_ec_pd_command(info, EC_CMD_USB_PD_CONTROL, 1,
165 				 &pd_control, sizeof(pd_control),
166 				 &resp, sizeof(resp));
167 	if (ret < 0)
168 		return ret;
169 
170 	if (!(resp.enabled & PD_CTRL_RESP_ENABLED_CONNECTED))
171 		return -ENOTCONN;
172 
173 	*polarity = resp.polarity;
174 
175 	return resp.role;
176 }
177 
178 /**
179  * cros_ec_pd_get_num_ports() - Get number of EC charge ports.
180  * @info: pointer to struct cros_ec_extcon_info
181  *
182  * Return: number of ports on success, <0 on failure.
183  */
184 static int cros_ec_pd_get_num_ports(struct cros_ec_extcon_info *info)
185 {
186 	struct ec_response_usb_pd_ports resp;
187 	int ret;
188 
189 	ret = cros_ec_pd_command(info, EC_CMD_USB_PD_PORTS,
190 				 0, NULL, 0, &resp, sizeof(resp));
191 	if (ret < 0)
192 		return ret;
193 
194 	return resp.num_ports;
195 }
196 
197 static const char *cros_ec_usb_role_string(unsigned int role)
198 {
199 	return role == DR_NONE ? "DISCONNECTED" :
200 		(role == DR_HOST ? "DFP" : "UFP");
201 }
202 
203 static const char *cros_ec_usb_power_type_string(unsigned int type)
204 {
205 	switch (type) {
206 	case USB_CHG_TYPE_NONE:
207 		return "USB_CHG_TYPE_NONE";
208 	case USB_CHG_TYPE_PD:
209 		return "USB_CHG_TYPE_PD";
210 	case USB_CHG_TYPE_PROPRIETARY:
211 		return "USB_CHG_TYPE_PROPRIETARY";
212 	case USB_CHG_TYPE_C:
213 		return "USB_CHG_TYPE_C";
214 	case USB_CHG_TYPE_BC12_DCP:
215 		return "USB_CHG_TYPE_BC12_DCP";
216 	case USB_CHG_TYPE_BC12_CDP:
217 		return "USB_CHG_TYPE_BC12_CDP";
218 	case USB_CHG_TYPE_BC12_SDP:
219 		return "USB_CHG_TYPE_BC12_SDP";
220 	case USB_CHG_TYPE_OTHER:
221 		return "USB_CHG_TYPE_OTHER";
222 	case USB_CHG_TYPE_VBUS:
223 		return "USB_CHG_TYPE_VBUS";
224 	case USB_CHG_TYPE_UNKNOWN:
225 		return "USB_CHG_TYPE_UNKNOWN";
226 	default:
227 		return "USB_CHG_TYPE_UNKNOWN";
228 	}
229 }
230 
231 static bool cros_ec_usb_power_type_is_wall_wart(unsigned int type,
232 						unsigned int role)
233 {
234 	switch (type) {
235 	/* FIXME : Guppy, Donnettes, and other chargers will be miscategorized
236 	 * because they identify with USB_CHG_TYPE_C, but we can't return true
237 	 * here from that code because that breaks Suzy-Q and other kinds of
238 	 * USB Type-C cables and peripherals.
239 	 */
240 	case USB_CHG_TYPE_PROPRIETARY:
241 	case USB_CHG_TYPE_BC12_DCP:
242 		return true;
243 	case USB_CHG_TYPE_PD:
244 	case USB_CHG_TYPE_C:
245 	case USB_CHG_TYPE_BC12_CDP:
246 	case USB_CHG_TYPE_BC12_SDP:
247 	case USB_CHG_TYPE_OTHER:
248 	case USB_CHG_TYPE_VBUS:
249 	case USB_CHG_TYPE_UNKNOWN:
250 	case USB_CHG_TYPE_NONE:
251 	default:
252 		return false;
253 	}
254 }
255 
256 static int extcon_cros_ec_detect_cable(struct cros_ec_extcon_info *info,
257 				       bool force)
258 {
259 	struct device *dev = info->dev;
260 	int role, power_type;
261 	unsigned int dr = DR_NONE;
262 	bool pr = false;
263 	bool polarity = false;
264 	bool dp = false;
265 	bool mux = false;
266 	bool hpd = false;
267 
268 	power_type = cros_ec_usb_get_power_type(info);
269 	if (power_type < 0) {
270 		dev_err(dev, "failed getting power type err = %d\n",
271 			power_type);
272 		return power_type;
273 	}
274 
275 	role = cros_ec_usb_get_role(info, &polarity);
276 	if (role < 0) {
277 		if (role != -ENOTCONN) {
278 			dev_err(dev, "failed getting role err = %d\n", role);
279 			return role;
280 		}
281 		dev_dbg(dev, "disconnected\n");
282 	} else {
283 		int pd_mux_state;
284 
285 		dr = (role & PD_CTRL_RESP_ROLE_DATA) ? DR_HOST : DR_DEVICE;
286 		pr = (role & PD_CTRL_RESP_ROLE_POWER);
287 		pd_mux_state = cros_ec_usb_get_pd_mux_state(info);
288 		if (pd_mux_state < 0)
289 			pd_mux_state = USB_PD_MUX_USB_ENABLED;
290 
291 		dp = pd_mux_state & USB_PD_MUX_DP_ENABLED;
292 		mux = pd_mux_state & USB_PD_MUX_USB_ENABLED;
293 		hpd = pd_mux_state & USB_PD_MUX_HPD_IRQ;
294 
295 		dev_dbg(dev,
296 			"connected role 0x%x pwr type %d dr %d pr %d pol %d mux %d dp %d hpd %d\n",
297 			role, power_type, dr, pr, polarity, mux, dp, hpd);
298 	}
299 
300 	/*
301 	 * When there is no USB host (e.g. USB PD charger),
302 	 * we are not really a UFP for the AP.
303 	 */
304 	if (dr == DR_DEVICE &&
305 	    cros_ec_usb_power_type_is_wall_wart(power_type, role))
306 		dr = DR_NONE;
307 
308 	if (force || info->dr != dr || info->pr != pr || info->dp != dp ||
309 	    info->mux != mux || info->power_type != power_type) {
310 		bool host_connected = false, device_connected = false;
311 
312 		dev_dbg(dev, "Type/Role switch! type = %s role = %s\n",
313 			cros_ec_usb_power_type_string(power_type),
314 			cros_ec_usb_role_string(dr));
315 		info->dr = dr;
316 		info->pr = pr;
317 		info->dp = dp;
318 		info->mux = mux;
319 		info->power_type = power_type;
320 
321 		if (dr == DR_DEVICE)
322 			device_connected = true;
323 		else if (dr == DR_HOST)
324 			host_connected = true;
325 
326 		extcon_set_state(info->edev, EXTCON_USB, device_connected);
327 		extcon_set_state(info->edev, EXTCON_USB_HOST, host_connected);
328 		extcon_set_state(info->edev, EXTCON_DISP_DP, dp);
329 		extcon_set_property(info->edev, EXTCON_USB,
330 				    EXTCON_PROP_USB_VBUS,
331 				    (union extcon_property_value)(int)pr);
332 		extcon_set_property(info->edev, EXTCON_USB_HOST,
333 				    EXTCON_PROP_USB_VBUS,
334 				    (union extcon_property_value)(int)pr);
335 		extcon_set_property(info->edev, EXTCON_USB,
336 				    EXTCON_PROP_USB_TYPEC_POLARITY,
337 				    (union extcon_property_value)(int)polarity);
338 		extcon_set_property(info->edev, EXTCON_USB_HOST,
339 				    EXTCON_PROP_USB_TYPEC_POLARITY,
340 				    (union extcon_property_value)(int)polarity);
341 		extcon_set_property(info->edev, EXTCON_DISP_DP,
342 				    EXTCON_PROP_USB_TYPEC_POLARITY,
343 				    (union extcon_property_value)(int)polarity);
344 		extcon_set_property(info->edev, EXTCON_USB,
345 				    EXTCON_PROP_USB_SS,
346 				    (union extcon_property_value)(int)mux);
347 		extcon_set_property(info->edev, EXTCON_USB_HOST,
348 				    EXTCON_PROP_USB_SS,
349 				    (union extcon_property_value)(int)mux);
350 		extcon_set_property(info->edev, EXTCON_DISP_DP,
351 				    EXTCON_PROP_USB_SS,
352 				    (union extcon_property_value)(int)mux);
353 		extcon_set_property(info->edev, EXTCON_DISP_DP,
354 				    EXTCON_PROP_DISP_HPD,
355 				    (union extcon_property_value)(int)hpd);
356 
357 		extcon_sync(info->edev, EXTCON_USB);
358 		extcon_sync(info->edev, EXTCON_USB_HOST);
359 		extcon_sync(info->edev, EXTCON_DISP_DP);
360 
361 	} else if (hpd) {
362 		extcon_set_property(info->edev, EXTCON_DISP_DP,
363 				    EXTCON_PROP_DISP_HPD,
364 				    (union extcon_property_value)(int)hpd);
365 		extcon_sync(info->edev, EXTCON_DISP_DP);
366 	}
367 
368 	return 0;
369 }
370 
371 static int extcon_cros_ec_event(struct notifier_block *nb,
372 				unsigned long queued_during_suspend,
373 				void *_notify)
374 {
375 	struct cros_ec_extcon_info *info;
376 	struct cros_ec_device *ec;
377 	u32 host_event;
378 
379 	info = container_of(nb, struct cros_ec_extcon_info, notifier);
380 	ec = info->ec;
381 
382 	host_event = cros_ec_get_host_event(ec);
383 	if (host_event & (EC_HOST_EVENT_MASK(EC_HOST_EVENT_PD_MCU) |
384 			  EC_HOST_EVENT_MASK(EC_HOST_EVENT_USB_MUX))) {
385 		extcon_cros_ec_detect_cable(info, false);
386 		return NOTIFY_OK;
387 	}
388 
389 	return NOTIFY_DONE;
390 }
391 
392 static int extcon_cros_ec_probe(struct platform_device *pdev)
393 {
394 	struct cros_ec_extcon_info *info;
395 	struct cros_ec_device *ec = dev_get_drvdata(pdev->dev.parent);
396 	struct device *dev = &pdev->dev;
397 	struct device_node *np = dev->of_node;
398 	int numports, ret;
399 
400 	info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
401 	if (!info)
402 		return -ENOMEM;
403 
404 	info->dev = dev;
405 	info->ec = ec;
406 
407 	if (np) {
408 		u32 port;
409 
410 		ret = of_property_read_u32(np, "google,usb-port-id", &port);
411 		if (ret < 0) {
412 			dev_err(dev, "Missing google,usb-port-id property\n");
413 			return ret;
414 		}
415 		info->port_id = port;
416 	} else {
417 		info->port_id = pdev->id;
418 	}
419 
420 	numports = cros_ec_pd_get_num_ports(info);
421 	if (numports < 0) {
422 		dev_err(dev, "failed getting number of ports! ret = %d\n",
423 			numports);
424 		return numports;
425 	}
426 
427 	if (info->port_id >= numports) {
428 		dev_err(dev, "This system only supports %d ports\n", numports);
429 		return -ENODEV;
430 	}
431 
432 	info->edev = devm_extcon_dev_allocate(dev, usb_type_c_cable);
433 	if (IS_ERR(info->edev)) {
434 		dev_err(dev, "failed to allocate extcon device\n");
435 		return -ENOMEM;
436 	}
437 
438 	ret = devm_extcon_dev_register(dev, info->edev);
439 	if (ret < 0) {
440 		dev_err(dev, "failed to register extcon device\n");
441 		return ret;
442 	}
443 
444 	extcon_set_property_capability(info->edev, EXTCON_USB,
445 				       EXTCON_PROP_USB_VBUS);
446 	extcon_set_property_capability(info->edev, EXTCON_USB_HOST,
447 				       EXTCON_PROP_USB_VBUS);
448 	extcon_set_property_capability(info->edev, EXTCON_USB,
449 				       EXTCON_PROP_USB_TYPEC_POLARITY);
450 	extcon_set_property_capability(info->edev, EXTCON_USB_HOST,
451 				       EXTCON_PROP_USB_TYPEC_POLARITY);
452 	extcon_set_property_capability(info->edev, EXTCON_DISP_DP,
453 				       EXTCON_PROP_USB_TYPEC_POLARITY);
454 	extcon_set_property_capability(info->edev, EXTCON_USB,
455 				       EXTCON_PROP_USB_SS);
456 	extcon_set_property_capability(info->edev, EXTCON_USB_HOST,
457 				       EXTCON_PROP_USB_SS);
458 	extcon_set_property_capability(info->edev, EXTCON_DISP_DP,
459 				       EXTCON_PROP_USB_SS);
460 	extcon_set_property_capability(info->edev, EXTCON_DISP_DP,
461 				       EXTCON_PROP_DISP_HPD);
462 
463 	info->dr = DR_NONE;
464 	info->pr = false;
465 
466 	platform_set_drvdata(pdev, info);
467 
468 	/* Get PD events from the EC */
469 	info->notifier.notifier_call = extcon_cros_ec_event;
470 	ret = blocking_notifier_chain_register(&info->ec->event_notifier,
471 					       &info->notifier);
472 	if (ret < 0) {
473 		dev_err(dev, "failed to register notifier\n");
474 		return ret;
475 	}
476 
477 	/* Perform initial detection */
478 	ret = extcon_cros_ec_detect_cable(info, true);
479 	if (ret < 0) {
480 		dev_err(dev, "failed to detect initial cable state\n");
481 		goto unregister_notifier;
482 	}
483 
484 	return 0;
485 
486 unregister_notifier:
487 	blocking_notifier_chain_unregister(&info->ec->event_notifier,
488 					   &info->notifier);
489 	return ret;
490 }
491 
492 static int extcon_cros_ec_remove(struct platform_device *pdev)
493 {
494 	struct cros_ec_extcon_info *info = platform_get_drvdata(pdev);
495 
496 	blocking_notifier_chain_unregister(&info->ec->event_notifier,
497 					   &info->notifier);
498 
499 	return 0;
500 }
501 
502 #ifdef CONFIG_PM_SLEEP
503 static int extcon_cros_ec_suspend(struct device *dev)
504 {
505 	return 0;
506 }
507 
508 static int extcon_cros_ec_resume(struct device *dev)
509 {
510 	int ret;
511 	struct cros_ec_extcon_info *info = dev_get_drvdata(dev);
512 
513 	ret = extcon_cros_ec_detect_cable(info, true);
514 	if (ret < 0)
515 		dev_err(dev, "failed to detect cable state on resume\n");
516 
517 	return 0;
518 }
519 
520 static const struct dev_pm_ops extcon_cros_ec_dev_pm_ops = {
521 	SET_SYSTEM_SLEEP_PM_OPS(extcon_cros_ec_suspend, extcon_cros_ec_resume)
522 };
523 
524 #define DEV_PM_OPS	(&extcon_cros_ec_dev_pm_ops)
525 #else
526 #define DEV_PM_OPS	NULL
527 #endif /* CONFIG_PM_SLEEP */
528 
529 #ifdef CONFIG_OF
530 static const struct of_device_id extcon_cros_ec_of_match[] = {
531 	{ .compatible = "google,extcon-usbc-cros-ec" },
532 	{ /* sentinel */ }
533 };
534 MODULE_DEVICE_TABLE(of, extcon_cros_ec_of_match);
535 #endif /* CONFIG_OF */
536 
537 static struct platform_driver extcon_cros_ec_driver = {
538 	.driver = {
539 		.name  = "extcon-usbc-cros-ec",
540 		.of_match_table = of_match_ptr(extcon_cros_ec_of_match),
541 		.pm = DEV_PM_OPS,
542 	},
543 	.remove  = extcon_cros_ec_remove,
544 	.probe   = extcon_cros_ec_probe,
545 };
546 
547 module_platform_driver(extcon_cros_ec_driver);
548 
549 MODULE_DESCRIPTION("ChromeOS Embedded Controller extcon driver");
550 MODULE_AUTHOR("Benson Leung <bleung@chromium.org>");
551 MODULE_LICENSE("GPL");
552