ucsi_yoga_c630.c

  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Copyright (c) 2022-2024, Linaro Ltd
  4 * Authors:
  5 *  Bjorn Andersson
  6 *  Dmitry Baryshkov
  7 */
  8#include <linux/auxiliary_bus.h>
  9#include <linux/bitops.h>
 10#include <linux/bitfield.h>
 11#include <linux/completion.h>
 12#include <linux/container_of.h>
 13#include <linux/module.h>
 14#include <linux/notifier.h>
 15#include <linux/of.h>
 16#include <linux/property.h>
 17#include <linux/string.h>
 18#include <linux/platform_data/lenovo-yoga-c630.h>
 19#include <linux/usb/typec_dp.h>
 20
 21#include <drm/bridge/aux-bridge.h>
 22
 23#include "ucsi.h"
 24
 25#define LENOVO_EC_USB_MUX	0x08
 26
 27#define USB_MUX_MUXC	GENMASK(1, 0)
 28#define USB_MUX_CCST	GENMASK(3, 2)
 29#define USB_MUX_DPPN	GENMASK(7, 4)
 30#define USB_MUX_HPDS	BIT(8)
 31#define USB_MUX_HSFL	GENMASK(11, 9)
 32
 33struct yoga_c630_ucsi {
 34	struct yoga_c630_ec *ec;
 35	struct ucsi *ucsi;
 36	struct auxiliary_device *bridge;
 37	struct notifier_block nb;
 38	u16 version;
 39};
 40
 41static int yoga_c630_ucsi_read_version(struct ucsi *ucsi, u16 *version)
 42{
 43	struct yoga_c630_ucsi *uec = ucsi_get_drvdata(ucsi);
 44
 45	*version = uec->version;
 46
 47	return 0;
 48}
 49
 50static int yoga_c630_ucsi_read_cci(struct ucsi *ucsi, u32 *cci)
 51{
 52	struct yoga_c630_ucsi *uec = ucsi_get_drvdata(ucsi);
 53	u8 buf[YOGA_C630_UCSI_READ_SIZE];
 54	int ret;
 55
 56	ret = yoga_c630_ec_ucsi_read(uec->ec, buf);
 57	if (ret)
 58		return ret;
 59
 60	memcpy(cci, buf, sizeof(*cci));
 61
 62	return 0;
 63}
 64
 65static int yoga_c630_ucsi_read_message_in(struct ucsi *ucsi,
 66					  void *val, size_t val_len)
 67{
 68	struct yoga_c630_ucsi *uec = ucsi_get_drvdata(ucsi);
 69	u8 buf[YOGA_C630_UCSI_READ_SIZE];
 70	int ret;
 71
 72	ret = yoga_c630_ec_ucsi_read(uec->ec, buf);
 73	if (ret)
 74		return ret;
 75
 76	memcpy(val, buf + YOGA_C630_UCSI_CCI_SIZE,
 77	       min(val_len, YOGA_C630_UCSI_DATA_SIZE));
 78
 79	return 0;
 80}
 81
 82static int yoga_c630_ucsi_async_control(struct ucsi *ucsi, u64 command)
 83{
 84	struct yoga_c630_ucsi *uec = ucsi_get_drvdata(ucsi);
 85
 86	return yoga_c630_ec_ucsi_write(uec->ec, (u8*)&command);
 87}
 88
 89static int yoga_c630_ucsi_sync_control(struct ucsi *ucsi,
 90				       u64 command,
 91				       u32 *cci,
 92				       void *data, size_t size)
 93{
 94	int ret;
 95
 96	/*
 97	 * EC doesn't return connector's DP mode even though it is supported.
 98	 * Fake it.
 99	 */
100	if (UCSI_COMMAND(command) == UCSI_GET_ALTERNATE_MODES &&
101	    UCSI_GET_ALTMODE_GET_CONNECTOR_NUMBER(command) == 1 &&
102	    UCSI_ALTMODE_RECIPIENT(command) == UCSI_RECIPIENT_CON &&
103	    UCSI_ALTMODE_OFFSET(command) == 0) {
104		static const struct ucsi_altmode alt = {
105			.svid = USB_TYPEC_DP_SID,
106			.mid = USB_TYPEC_DP_MODE,
107		};
108
109		dev_dbg(ucsi->dev, "faking DP altmode for con1\n");
110		memset(data, 0, size);
111		memcpy(data, &alt, min(sizeof(alt), size));
112		*cci = UCSI_CCI_COMMAND_COMPLETE | UCSI_SET_CCI_LENGTH(sizeof(alt));
113		return 0;
114	}
115
116	/*
117	 * EC can return AltModes present on CON1 (port0, right) for CON2
118	 * (port1, left) too. Ignore all requests going to CON2 (it doesn't
119	 * support DP anyway).
120	 */
121	if (UCSI_COMMAND(command) == UCSI_GET_ALTERNATE_MODES &&
122	    UCSI_GET_ALTMODE_GET_CONNECTOR_NUMBER(command) == 2) {
123		dev_dbg(ucsi->dev, "ignoring altmodes for con2\n");
124		memset(data, 0, size);
125		*cci = UCSI_CCI_COMMAND_COMPLETE;
126		return 0;
127	}
128
129	ret = ucsi_sync_control_common(ucsi, command, cci, data, size);
130	if (ret < 0)
131		return ret;
132
133	/* UCSI_GET_CURRENT_CAM is off-by-one on all ports */
134	if (UCSI_COMMAND(command) == UCSI_GET_CURRENT_CAM && data)
135		((u8 *)data)[0]--;
136
137	return ret;
138}
139
140static bool yoga_c630_ucsi_update_altmodes(struct ucsi *ucsi,
141					   u8 recipient,
142					   struct ucsi_altmode *orig,
143					   struct ucsi_altmode *updated)
144{
145	int i;
146
147	if (orig[0].svid == 0 || recipient != UCSI_RECIPIENT_SOP)
148		return false;
149
150	/* EC is nice and repeats altmodes again and again. Ignore copies. */
151	for (i = 1; i < UCSI_MAX_ALTMODES; i++) {
152		if (orig[i].svid == orig[0].svid) {
153			dev_dbg(ucsi->dev, "Found duplicate altmodes, starting from %d\n", i);
154			memset(&orig[i], 0, (UCSI_MAX_ALTMODES - i) * sizeof(*orig));
155			break;
156		}
157	}
158
159	return false;
160}
161
162static void yoga_c630_ucsi_update_connector(struct ucsi_connector *con)
163{
164	if (con->num == 1)
165		con->typec_cap.orientation_aware = true;
166}
167
168static const struct ucsi_operations yoga_c630_ucsi_ops = {
169	.read_version = yoga_c630_ucsi_read_version,
170	.read_cci = yoga_c630_ucsi_read_cci,
171	.poll_cci = yoga_c630_ucsi_read_cci,
172	.read_message_in = yoga_c630_ucsi_read_message_in,
173	.sync_control = yoga_c630_ucsi_sync_control,
174	.async_control = yoga_c630_ucsi_async_control,
175	.update_altmodes = yoga_c630_ucsi_update_altmodes,
176	.update_connector = yoga_c630_ucsi_update_connector,
177};
178
179static void yoga_c630_ucsi_read_port0_status(struct yoga_c630_ucsi *uec)
180{
181	int val;
182	unsigned int muxc, ccst, dppn, hpds, hsfl;
183
184	val = yoga_c630_ec_read16(uec->ec, LENOVO_EC_USB_MUX);
185
186	muxc = FIELD_GET(USB_MUX_MUXC, val);
187	ccst = FIELD_GET(USB_MUX_CCST, val);
188	dppn = FIELD_GET(USB_MUX_DPPN, val);
189	hpds = FIELD_GET(USB_MUX_HPDS, val);
190	hsfl = FIELD_GET(USB_MUX_HSFL, val);
191
192	dev_dbg(uec->ucsi->dev, " mux %04x (muxc %d ccst %d dppn %d hpds %d hsfl %d)\n",
193		val,
194		muxc, ccst, dppn, hpds, hsfl);
195
196	if (uec->ucsi->connector && uec->ucsi->connector[0].port)
197		typec_set_orientation(uec->ucsi->connector[0].port,
198				      ccst == 1 ?
199				      TYPEC_ORIENTATION_REVERSE :
200				      TYPEC_ORIENTATION_NORMAL);
201
202	if (uec->bridge)
203		drm_aux_hpd_bridge_notify(&uec->bridge->dev,
204					  dppn != 0 ?
205					  connector_status_connected :
206					  connector_status_disconnected);
207
208}
209
210static int yoga_c630_ucsi_notify(struct notifier_block *nb,
211				 unsigned long action, void *data)
212{
213	struct yoga_c630_ucsi *uec = container_of(nb, struct yoga_c630_ucsi, nb);
214	u32 cci;
215	int ret;
216
217	switch (action) {
218	case LENOVO_EC_EVENT_USB:
219	case LENOVO_EC_EVENT_HPD:
220		yoga_c630_ucsi_read_port0_status(uec);
221		ucsi_connector_change(uec->ucsi, 1);
222		return NOTIFY_OK;
223
224	case LENOVO_EC_EVENT_UCSI:
225		ret = uec->ucsi->ops->read_cci(uec->ucsi, &cci);
226		if (ret)
227			return NOTIFY_DONE;
228
229		ucsi_notify_common(uec->ucsi, cci);
230
231		return NOTIFY_OK;
232
233	default:
234		return NOTIFY_DONE;
235	}
236}
237
238static int yoga_c630_ucsi_probe(struct auxiliary_device *adev,
239				const struct auxiliary_device_id *id)
240{
241	struct yoga_c630_ec *ec = adev->dev.platform_data;
242	struct yoga_c630_ucsi *uec;
243	int ret;
244
245	uec = devm_kzalloc(&adev->dev, sizeof(*uec), GFP_KERNEL);
246	if (!uec)
247		return -ENOMEM;
248
249	uec->ec = ec;
250	uec->nb.notifier_call = yoga_c630_ucsi_notify;
251
252	device_for_each_child_node_scoped(&adev->dev, fwnode) {
253		u32 port;
254
255		ret = fwnode_property_read_u32(fwnode, "reg", &port);
256		if (ret < 0) {
257			dev_err(&adev->dev, "missing reg property of %pfwP\n", fwnode);
258			return ret;
259		}
260
261		/* DP is only on port0 */
262		if (port != 0)
263			continue;
264
265		uec->bridge = devm_drm_dp_hpd_bridge_alloc(&adev->dev, to_of_node(fwnode));
266		if (IS_ERR(uec->bridge))
267			return PTR_ERR(uec->bridge);
268	}
269
270	uec->ucsi = ucsi_create(&adev->dev, &yoga_c630_ucsi_ops);
271	if (IS_ERR(uec->ucsi))
272		return PTR_ERR(uec->ucsi);
273
274	ucsi_set_drvdata(uec->ucsi, uec);
275
276	uec->version = yoga_c630_ec_ucsi_get_version(uec->ec);
277
278	auxiliary_set_drvdata(adev, uec);
279
280	ret = yoga_c630_ec_register_notify(ec, &uec->nb);
281	if (ret)
282		goto err_destroy;
283
284	ret = ucsi_register(uec->ucsi);
285	if (ret)
286		goto err_unregister;
287
288	if (uec->bridge) {
289		ret = devm_drm_dp_hpd_bridge_add(&adev->dev, uec->bridge);
290		if (ret)
291			goto err_ucsi_unregister;
292	}
293
294	return 0;
295
296err_ucsi_unregister:
297	ucsi_unregister(uec->ucsi);
298
299err_unregister:
300	yoga_c630_ec_unregister_notify(uec->ec, &uec->nb);
301
302err_destroy:
303	ucsi_destroy(uec->ucsi);
304
305	return ret;
306}
307
308static void yoga_c630_ucsi_remove(struct auxiliary_device *adev)
309{
310	struct yoga_c630_ucsi *uec = auxiliary_get_drvdata(adev);
311
312	ucsi_unregister(uec->ucsi);
313	yoga_c630_ec_unregister_notify(uec->ec, &uec->nb);
314	ucsi_destroy(uec->ucsi);
315}
316
317static const struct auxiliary_device_id yoga_c630_ucsi_id_table[] = {
318	{ .name = YOGA_C630_MOD_NAME "." YOGA_C630_DEV_UCSI, },
319	{}
320};
321MODULE_DEVICE_TABLE(auxiliary, yoga_c630_ucsi_id_table);
322
323static struct auxiliary_driver yoga_c630_ucsi_driver = {
324	.name = YOGA_C630_DEV_UCSI,
325	.id_table = yoga_c630_ucsi_id_table,
326	.probe = yoga_c630_ucsi_probe,
327	.remove = yoga_c630_ucsi_remove,
328};
329
330module_auxiliary_driver(yoga_c630_ucsi_driver);
331
332MODULE_DESCRIPTION("Lenovo Yoga C630 UCSI");
333MODULE_LICENSE("GPL");