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
 27struct 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
 44static const unsigned int usb_type_c_cable[] = {
 45	EXTCON_USB,
 46	EXTCON_USB_HOST,
 47	EXTCON_DISP_DP,
 48	EXTCON_NONE,
 49};
 50
 51enum 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 */
 69static 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 */
107static 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 */
128static 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 */
153static 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 */
184static 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
197static 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
203static 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
231static 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
256static 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
371static 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
392static 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
486unregister_notifier:
487	blocking_notifier_chain_unregister(&info->ec->event_notifier,
488					   &info->notifier);
489	return ret;
490}
491
492static 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
503static int extcon_cros_ec_suspend(struct device *dev)
504{
505	return 0;
506}
507
508static 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
520static 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
530static const struct of_device_id extcon_cros_ec_of_match[] = {
531	{ .compatible = "google,extcon-usbc-cros-ec" },
532	{ /* sentinel */ }
533};
534MODULE_DEVICE_TABLE(of, extcon_cros_ec_of_match);
535#endif /* CONFIG_OF */
536
537static 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
547module_platform_driver(extcon_cros_ec_driver);
548
549MODULE_DESCRIPTION("ChromeOS Embedded Controller extcon driver");
550MODULE_AUTHOR("Benson Leung <bleung@chromium.org>");
551MODULE_LICENSE("GPL");