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