1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * CEC driver for ChromeOS Embedded Controller
4 *
5 * Copyright (c) 2018 BayLibre, SAS
6 * Author: Neil Armstrong <narmstrong@baylibre.com>
7 */
8
9#include <linux/kernel.h>
10#include <linux/module.h>
11#include <linux/platform_device.h>
12#include <linux/dmi.h>
13#include <linux/pci.h>
14#include <linux/cec.h>
15#include <linux/slab.h>
16#include <linux/interrupt.h>
17#include <linux/platform_data/cros_ec_commands.h>
18#include <linux/platform_data/cros_ec_proto.h>
19#include <media/cec.h>
20#include <media/cec-notifier.h>
21
22#define DRV_NAME	"cros-ec-cec"
23
24/**
25 * struct cros_ec_cec - Driver data for EC CEC
26 *
27 * @cros_ec: Pointer to EC device
28 * @notifier: Notifier info for responding to EC events
29 * @adap: CEC adapter
30 * @notify: CEC notifier pointer
31 * @rx_msg: storage for a received message
32 */
33struct cros_ec_cec {
34	struct cros_ec_device *cros_ec;
35	struct notifier_block notifier;
36	struct cec_adapter *adap;
37	struct cec_notifier *notify;
38	struct cec_msg rx_msg;
39};
40
41static void handle_cec_message(struct cros_ec_cec *cros_ec_cec)
42{
43	struct cros_ec_device *cros_ec = cros_ec_cec->cros_ec;
44	uint8_t *cec_message = cros_ec->event_data.data.cec_message;
45	unsigned int len = cros_ec->event_size;
46
47	if (len > CEC_MAX_MSG_SIZE)
48		len = CEC_MAX_MSG_SIZE;
49	cros_ec_cec->rx_msg.len = len;
50	memcpy(cros_ec_cec->rx_msg.msg, cec_message, len);
51
52	cec_received_msg(cros_ec_cec->adap, &cros_ec_cec->rx_msg);
53}
54
55static void handle_cec_event(struct cros_ec_cec *cros_ec_cec)
56{
57	struct cros_ec_device *cros_ec = cros_ec_cec->cros_ec;
58	uint32_t events = cros_ec->event_data.data.cec_events;
59
60	if (events & EC_MKBP_CEC_SEND_OK)
61		cec_transmit_attempt_done(cros_ec_cec->adap,
62					  CEC_TX_STATUS_OK);
63
64	/* FW takes care of all retries, tell core to avoid more retries */
65	if (events & EC_MKBP_CEC_SEND_FAILED)
66		cec_transmit_attempt_done(cros_ec_cec->adap,
67					  CEC_TX_STATUS_MAX_RETRIES |
68					  CEC_TX_STATUS_NACK);
69}
70
71static int cros_ec_cec_event(struct notifier_block *nb,
72			     unsigned long queued_during_suspend,
73			     void *_notify)
74{
75	struct cros_ec_cec *cros_ec_cec;
76	struct cros_ec_device *cros_ec;
77
78	cros_ec_cec = container_of(nb, struct cros_ec_cec, notifier);
79	cros_ec = cros_ec_cec->cros_ec;
80
81	if (cros_ec->event_data.event_type == EC_MKBP_EVENT_CEC_EVENT) {
82		handle_cec_event(cros_ec_cec);
83		return NOTIFY_OK;
84	}
85
86	if (cros_ec->event_data.event_type == EC_MKBP_EVENT_CEC_MESSAGE) {
87		handle_cec_message(cros_ec_cec);
88		return NOTIFY_OK;
89	}
90
91	return NOTIFY_DONE;
92}
93
94static int cros_ec_cec_set_log_addr(struct cec_adapter *adap, u8 logical_addr)
95{
96	struct cros_ec_cec *cros_ec_cec = adap->priv;
97	struct cros_ec_device *cros_ec = cros_ec_cec->cros_ec;
98	struct {
99		struct cros_ec_command msg;
100		struct ec_params_cec_set data;
101	} __packed msg = {};
102	int ret;
103
104	msg.msg.command = EC_CMD_CEC_SET;
105	msg.msg.outsize = sizeof(msg.data);
106	msg.data.cmd = CEC_CMD_LOGICAL_ADDRESS;
107	msg.data.val = logical_addr;
108
109	ret = cros_ec_cmd_xfer_status(cros_ec, &msg.msg);
110	if (ret < 0) {
111		dev_err(cros_ec->dev,
112			"error setting CEC logical address on EC: %d\n", ret);
113		return ret;
114	}
115
116	return 0;
117}
118
119static int cros_ec_cec_transmit(struct cec_adapter *adap, u8 attempts,
120				u32 signal_free_time, struct cec_msg *cec_msg)
121{
122	struct cros_ec_cec *cros_ec_cec = adap->priv;
123	struct cros_ec_device *cros_ec = cros_ec_cec->cros_ec;
124	struct {
125		struct cros_ec_command msg;
126		struct ec_params_cec_write data;
127	} __packed msg = {};
128	int ret;
129
130	msg.msg.command = EC_CMD_CEC_WRITE_MSG;
131	msg.msg.outsize = cec_msg->len;
132	memcpy(msg.data.msg, cec_msg->msg, cec_msg->len);
133
134	ret = cros_ec_cmd_xfer_status(cros_ec, &msg.msg);
135	if (ret < 0) {
136		dev_err(cros_ec->dev,
137			"error writing CEC msg on EC: %d\n", ret);
138		return ret;
139	}
140
141	return 0;
142}
143
144static int cros_ec_cec_adap_enable(struct cec_adapter *adap, bool enable)
145{
146	struct cros_ec_cec *cros_ec_cec = adap->priv;
147	struct cros_ec_device *cros_ec = cros_ec_cec->cros_ec;
148	struct {
149		struct cros_ec_command msg;
150		struct ec_params_cec_set data;
151	} __packed msg = {};
152	int ret;
153
154	msg.msg.command = EC_CMD_CEC_SET;
155	msg.msg.outsize = sizeof(msg.data);
156	msg.data.cmd = CEC_CMD_ENABLE;
157	msg.data.val = enable;
158
159	ret = cros_ec_cmd_xfer_status(cros_ec, &msg.msg);
160	if (ret < 0) {
161		dev_err(cros_ec->dev,
162			"error %sabling CEC on EC: %d\n",
163			(enable ? "en" : "dis"), ret);
164		return ret;
165	}
166
167	return 0;
168}
169
170static const struct cec_adap_ops cros_ec_cec_ops = {
171	.adap_enable = cros_ec_cec_adap_enable,
172	.adap_log_addr = cros_ec_cec_set_log_addr,
173	.adap_transmit = cros_ec_cec_transmit,
174};
175
176#ifdef CONFIG_PM_SLEEP
177static int cros_ec_cec_suspend(struct device *dev)
178{
179	struct platform_device *pdev = to_platform_device(dev);
180	struct cros_ec_cec *cros_ec_cec = dev_get_drvdata(&pdev->dev);
181
182	if (device_may_wakeup(dev))
183		enable_irq_wake(cros_ec_cec->cros_ec->irq);
184
185	return 0;
186}
187
188static int cros_ec_cec_resume(struct device *dev)
189{
190	struct platform_device *pdev = to_platform_device(dev);
191	struct cros_ec_cec *cros_ec_cec = dev_get_drvdata(&pdev->dev);
192
193	if (device_may_wakeup(dev))
194		disable_irq_wake(cros_ec_cec->cros_ec->irq);
195
196	return 0;
197}
198#endif
199
200static SIMPLE_DEV_PM_OPS(cros_ec_cec_pm_ops,
201	cros_ec_cec_suspend, cros_ec_cec_resume);
202
203#if IS_ENABLED(CONFIG_PCI) && IS_ENABLED(CONFIG_DMI)
204
205/*
206 * The Firmware only handles a single CEC interface tied to a single HDMI
207 * connector we specify along with the DRM device name handling the HDMI output
208 */
209
210struct cec_dmi_match {
211	const char *sys_vendor;
212	const char *product_name;
213	const char *devname;
214	const char *conn;
215};
216
217static const struct cec_dmi_match cec_dmi_match_table[] = {
218	/* Google Fizz */
219	{ "Google", "Fizz", "0000:00:02.0", "Port B" },
220};
221
222static struct device *cros_ec_cec_find_hdmi_dev(struct device *dev,
223						const char **conn)
224{
225	int i;
226
227	for (i = 0 ; i < ARRAY_SIZE(cec_dmi_match_table) ; ++i) {
228		const struct cec_dmi_match *m = &cec_dmi_match_table[i];
229
230		if (dmi_match(DMI_SYS_VENDOR, m->sys_vendor) &&
231		    dmi_match(DMI_PRODUCT_NAME, m->product_name)) {
232			struct device *d;
233
234			/* Find the device, bail out if not yet registered */
235			d = bus_find_device_by_name(&pci_bus_type, NULL,
236						    m->devname);
237			if (!d)
238				return ERR_PTR(-EPROBE_DEFER);
239			put_device(d);
240			*conn = m->conn;
241			return d;
242		}
243	}
244
245	/* Hardware support must be added in the cec_dmi_match_table */
246	dev_warn(dev, "CEC notifier not configured for this hardware\n");
247
248	return ERR_PTR(-ENODEV);
249}
250
251#else
252
253static struct device *cros_ec_cec_find_hdmi_dev(struct device *dev,
254						const char **conn)
255{
256	return ERR_PTR(-ENODEV);
257}
258
259#endif
260
261static int cros_ec_cec_probe(struct platform_device *pdev)
262{
263	struct cros_ec_dev *ec_dev = dev_get_drvdata(pdev->dev.parent);
264	struct cros_ec_device *cros_ec = ec_dev->ec_dev;
265	struct cros_ec_cec *cros_ec_cec;
266	struct device *hdmi_dev;
267	const char *conn = NULL;
268	int ret;
269
270	hdmi_dev = cros_ec_cec_find_hdmi_dev(&pdev->dev, &conn);
271	if (IS_ERR(hdmi_dev))
272		return PTR_ERR(hdmi_dev);
273
274	cros_ec_cec = devm_kzalloc(&pdev->dev, sizeof(*cros_ec_cec),
275				   GFP_KERNEL);
276	if (!cros_ec_cec)
277		return -ENOMEM;
278
279	platform_set_drvdata(pdev, cros_ec_cec);
280	cros_ec_cec->cros_ec = cros_ec;
281
282	device_init_wakeup(&pdev->dev, 1);
283
284	cros_ec_cec->adap = cec_allocate_adapter(&cros_ec_cec_ops, cros_ec_cec,
285						 DRV_NAME,
286						 CEC_CAP_DEFAULTS |
287						 CEC_CAP_CONNECTOR_INFO, 1);
288	if (IS_ERR(cros_ec_cec->adap))
289		return PTR_ERR(cros_ec_cec->adap);
290
291	cros_ec_cec->notify = cec_notifier_cec_adap_register(hdmi_dev, conn,
292							     cros_ec_cec->adap);
293	if (!cros_ec_cec->notify) {
294		ret = -ENOMEM;
295		goto out_probe_adapter;
296	}
297
298	/* Get CEC events from the EC. */
299	cros_ec_cec->notifier.notifier_call = cros_ec_cec_event;
300	ret = blocking_notifier_chain_register(&cros_ec->event_notifier,
301					       &cros_ec_cec->notifier);
302	if (ret) {
303		dev_err(&pdev->dev, "failed to register notifier\n");
304		goto out_probe_notify;
305	}
306
307	ret = cec_register_adapter(cros_ec_cec->adap, &pdev->dev);
308	if (ret < 0)
309		goto out_probe_notify;
310
311	return 0;
312
313out_probe_notify:
314	cec_notifier_cec_adap_unregister(cros_ec_cec->notify,
315					 cros_ec_cec->adap);
316out_probe_adapter:
317	cec_delete_adapter(cros_ec_cec->adap);
318	return ret;
319}
320
321static int cros_ec_cec_remove(struct platform_device *pdev)
322{
323	struct cros_ec_cec *cros_ec_cec = platform_get_drvdata(pdev);
324	struct device *dev = &pdev->dev;
325	int ret;
326
327	ret = blocking_notifier_chain_unregister(
328			&cros_ec_cec->cros_ec->event_notifier,
329			&cros_ec_cec->notifier);
330
331	if (ret) {
332		dev_err(dev, "failed to unregister notifier\n");
333		return ret;
334	}
335
336	cec_notifier_cec_adap_unregister(cros_ec_cec->notify,
337					 cros_ec_cec->adap);
338	cec_unregister_adapter(cros_ec_cec->adap);
339
340	return 0;
341}
342
343static struct platform_driver cros_ec_cec_driver = {
344	.probe = cros_ec_cec_probe,
345	.remove  = cros_ec_cec_remove,
346	.driver = {
347		.name = DRV_NAME,
348		.pm = &cros_ec_cec_pm_ops,
349	},
350};
351
352module_platform_driver(cros_ec_cec_driver);
353
354MODULE_DESCRIPTION("CEC driver for ChromeOS ECs");
355MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
356MODULE_LICENSE("GPL");
357MODULE_ALIAS("platform:" DRV_NAME);
358