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
18struct 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
35static const unsigned int usb_type_c_cable[] = {
36	EXTCON_USB,
37	EXTCON_USB_HOST,
38	EXTCON_DISP_DP,
39	EXTCON_NONE,
40};
41
42enum 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 */
60static 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 */
98static 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 */
119static 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 */
144static 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 */
175static 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
188static 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
194static 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
222static 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
247static 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
362static 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
383static 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
477unregister_notifier:
478	blocking_notifier_chain_unregister(&info->ec->event_notifier,
479					   &info->notifier);
480	return ret;
481}
482
483static 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
494static int extcon_cros_ec_suspend(struct device *dev)
495{
496	return 0;
497}
498
499static 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
511static 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
521static const struct of_device_id extcon_cros_ec_of_match[] = {
522	{ .compatible = "google,extcon-usbc-cros-ec" },
523	{ /* sentinel */ }
524};
525MODULE_DEVICE_TABLE(of, extcon_cros_ec_of_match);
526#endif /* CONFIG_OF */
527
528static 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
538module_platform_driver(extcon_cros_ec_driver);
539
540MODULE_DESCRIPTION("ChromeOS Embedded Controller extcon driver");
541MODULE_AUTHOR("Benson Leung <bleung@chromium.org>");
542MODULE_LICENSE("GPL v2");
543