1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * TDA9950 Consumer Electronics Control driver |
4 | * |
5 | * The NXP TDA9950 implements the HDMI Consumer Electronics Control |
6 | * interface. The host interface is similar to a mailbox: the data |
7 | * registers starting at REG_CDR0 are written to send a command to the |
8 | * internal CPU, and replies are read from these registers. |
9 | * |
10 | * As the data registers represent a mailbox, they must be accessed |
11 | * as a single I2C transaction. See the TDA9950 data sheet for details. |
12 | */ |
13 | #include <linux/delay.h> |
14 | #include <linux/i2c.h> |
15 | #include <linux/interrupt.h> |
16 | #include <linux/module.h> |
17 | #include <linux/platform_data/tda9950.h> |
18 | #include <linux/slab.h> |
19 | #include <drm/drm_edid.h> |
20 | #include <media/cec.h> |
21 | #include <media/cec-notifier.h> |
22 | |
23 | enum { |
24 | REG_CSR = 0x00, |
25 | CSR_BUSY = BIT(7), |
26 | CSR_INT = BIT(6), |
27 | CSR_ERR = BIT(5), |
28 | |
29 | REG_CER = 0x01, |
30 | |
31 | REG_CVR = 0x02, |
32 | |
33 | REG_CCR = 0x03, |
34 | CCR_RESET = BIT(7), |
35 | CCR_ON = BIT(6), |
36 | |
37 | REG_ACKH = 0x04, |
38 | REG_ACKL = 0x05, |
39 | |
40 | REG_CCONR = 0x06, |
41 | CCONR_ENABLE_ERROR = BIT(4), |
42 | CCONR_RETRY_MASK = 7, |
43 | |
44 | REG_CDR0 = 0x07, |
45 | |
46 | CDR1_REQ = 0x00, |
47 | CDR1_CNF = 0x01, |
48 | CDR1_IND = 0x81, |
49 | CDR1_ERR = 0x82, |
50 | CDR1_IER = 0x83, |
51 | |
52 | CDR2_CNF_SUCCESS = 0x00, |
53 | CDR2_CNF_OFF_STATE = 0x80, |
54 | CDR2_CNF_BAD_REQ = 0x81, |
55 | CDR2_CNF_CEC_ACCESS = 0x82, |
56 | CDR2_CNF_ARB_ERROR = 0x83, |
57 | CDR2_CNF_BAD_TIMING = 0x84, |
58 | CDR2_CNF_NACK_ADDR = 0x85, |
59 | CDR2_CNF_NACK_DATA = 0x86, |
60 | }; |
61 | |
62 | struct tda9950_priv { |
63 | struct i2c_client *client; |
64 | struct device *hdmi; |
65 | struct cec_adapter *adap; |
66 | struct tda9950_glue *glue; |
67 | u16 addresses; |
68 | struct cec_msg rx_msg; |
69 | struct cec_notifier *notify; |
70 | bool open; |
71 | }; |
72 | |
73 | static int tda9950_write_range(struct i2c_client *client, u8 addr, u8 *p, int cnt) |
74 | { |
75 | struct i2c_msg msg; |
76 | u8 buf[CEC_MAX_MSG_SIZE + 3]; |
77 | int ret; |
78 | |
79 | if (WARN_ON(cnt > sizeof(buf) - 1)) |
80 | return -EINVAL; |
81 | |
82 | buf[0] = addr; |
83 | memcpy(buf + 1, p, cnt); |
84 | |
85 | msg.addr = client->addr; |
86 | msg.flags = 0; |
87 | msg.len = cnt + 1; |
88 | msg.buf = buf; |
89 | |
90 | dev_dbg(&client->dev, "wr 0x%02x: %*ph\n" , addr, cnt, p); |
91 | |
92 | ret = i2c_transfer(adap: client->adapter, msgs: &msg, num: 1); |
93 | if (ret < 0) |
94 | dev_err(&client->dev, "Error %d writing to cec:0x%x\n" , ret, addr); |
95 | return ret < 0 ? ret : 0; |
96 | } |
97 | |
98 | static void tda9950_write(struct i2c_client *client, u8 addr, u8 val) |
99 | { |
100 | tda9950_write_range(client, addr, p: &val, cnt: 1); |
101 | } |
102 | |
103 | static int tda9950_read_range(struct i2c_client *client, u8 addr, u8 *p, int cnt) |
104 | { |
105 | struct i2c_msg msg[2]; |
106 | int ret; |
107 | |
108 | msg[0].addr = client->addr; |
109 | msg[0].flags = 0; |
110 | msg[0].len = 1; |
111 | msg[0].buf = &addr; |
112 | msg[1].addr = client->addr; |
113 | msg[1].flags = I2C_M_RD; |
114 | msg[1].len = cnt; |
115 | msg[1].buf = p; |
116 | |
117 | ret = i2c_transfer(adap: client->adapter, msgs: msg, num: 2); |
118 | if (ret < 0) |
119 | dev_err(&client->dev, "Error %d reading from cec:0x%x\n" , ret, addr); |
120 | |
121 | dev_dbg(&client->dev, "rd 0x%02x: %*ph\n" , addr, cnt, p); |
122 | |
123 | return ret; |
124 | } |
125 | |
126 | static u8 tda9950_read(struct i2c_client *client, u8 addr) |
127 | { |
128 | int ret; |
129 | u8 val; |
130 | |
131 | ret = tda9950_read_range(client, addr, p: &val, cnt: 1); |
132 | if (ret < 0) |
133 | val = 0; |
134 | |
135 | return val; |
136 | } |
137 | |
138 | static irqreturn_t tda9950_irq(int irq, void *data) |
139 | { |
140 | struct tda9950_priv *priv = data; |
141 | unsigned int tx_status; |
142 | u8 csr, cconr, buf[19]; |
143 | u8 arb_lost_cnt, nack_cnt, err_cnt; |
144 | |
145 | if (!priv->open) |
146 | return IRQ_NONE; |
147 | |
148 | csr = tda9950_read(client: priv->client, addr: REG_CSR); |
149 | if (!(csr & CSR_INT)) |
150 | return IRQ_NONE; |
151 | |
152 | cconr = tda9950_read(client: priv->client, addr: REG_CCONR) & CCONR_RETRY_MASK; |
153 | |
154 | tda9950_read_range(client: priv->client, addr: REG_CDR0, p: buf, cnt: sizeof(buf)); |
155 | |
156 | /* |
157 | * This should never happen: the data sheet says that there will |
158 | * always be a valid message if the interrupt line is asserted. |
159 | */ |
160 | if (buf[0] == 0) { |
161 | dev_warn(&priv->client->dev, "interrupt pending, but no message?\n" ); |
162 | return IRQ_NONE; |
163 | } |
164 | |
165 | switch (buf[1]) { |
166 | case CDR1_CNF: /* transmit result */ |
167 | arb_lost_cnt = nack_cnt = err_cnt = 0; |
168 | switch (buf[2]) { |
169 | case CDR2_CNF_SUCCESS: |
170 | tx_status = CEC_TX_STATUS_OK; |
171 | break; |
172 | |
173 | case CDR2_CNF_ARB_ERROR: |
174 | tx_status = CEC_TX_STATUS_ARB_LOST; |
175 | arb_lost_cnt = cconr; |
176 | break; |
177 | |
178 | case CDR2_CNF_NACK_ADDR: |
179 | tx_status = CEC_TX_STATUS_NACK; |
180 | nack_cnt = cconr; |
181 | break; |
182 | |
183 | default: /* some other error, refer to TDA9950 docs */ |
184 | dev_err(&priv->client->dev, "CNF reply error 0x%02x\n" , |
185 | buf[2]); |
186 | tx_status = CEC_TX_STATUS_ERROR; |
187 | err_cnt = cconr; |
188 | break; |
189 | } |
190 | /* TDA9950 executes all retries for us */ |
191 | if (tx_status != CEC_TX_STATUS_OK) |
192 | tx_status |= CEC_TX_STATUS_MAX_RETRIES; |
193 | cec_transmit_done(adap: priv->adap, status: tx_status, arb_lost_cnt, |
194 | nack_cnt, low_drive_cnt: 0, error_cnt: err_cnt); |
195 | break; |
196 | |
197 | case CDR1_IND: |
198 | priv->rx_msg.len = buf[0] - 2; |
199 | if (priv->rx_msg.len > CEC_MAX_MSG_SIZE) |
200 | priv->rx_msg.len = CEC_MAX_MSG_SIZE; |
201 | |
202 | memcpy(priv->rx_msg.msg, buf + 2, priv->rx_msg.len); |
203 | cec_received_msg(adap: priv->adap, msg: &priv->rx_msg); |
204 | break; |
205 | |
206 | default: /* unknown */ |
207 | dev_err(&priv->client->dev, "unknown service id 0x%02x\n" , |
208 | buf[1]); |
209 | break; |
210 | } |
211 | |
212 | return IRQ_HANDLED; |
213 | } |
214 | |
215 | static int tda9950_cec_transmit(struct cec_adapter *adap, u8 attempts, |
216 | u32 signal_free_time, struct cec_msg *msg) |
217 | { |
218 | struct tda9950_priv *priv = adap->priv; |
219 | u8 buf[CEC_MAX_MSG_SIZE + 2]; |
220 | |
221 | buf[0] = 2 + msg->len; |
222 | buf[1] = CDR1_REQ; |
223 | memcpy(buf + 2, msg->msg, msg->len); |
224 | |
225 | if (attempts > 5) |
226 | attempts = 5; |
227 | |
228 | tda9950_write(client: priv->client, addr: REG_CCONR, val: attempts); |
229 | |
230 | return tda9950_write_range(client: priv->client, addr: REG_CDR0, p: buf, cnt: 2 + msg->len); |
231 | } |
232 | |
233 | static int tda9950_cec_adap_log_addr(struct cec_adapter *adap, u8 addr) |
234 | { |
235 | struct tda9950_priv *priv = adap->priv; |
236 | u16 addresses; |
237 | u8 buf[2]; |
238 | |
239 | if (addr == CEC_LOG_ADDR_INVALID) |
240 | addresses = priv->addresses = 0; |
241 | else |
242 | addresses = priv->addresses |= BIT(addr); |
243 | |
244 | /* TDA9950 doesn't want address 15 set */ |
245 | addresses &= 0x7fff; |
246 | buf[0] = addresses >> 8; |
247 | buf[1] = addresses; |
248 | |
249 | return tda9950_write_range(client: priv->client, addr: REG_ACKH, p: buf, cnt: 2); |
250 | } |
251 | |
252 | /* |
253 | * When operating as part of the TDA998x, we need additional handling |
254 | * to initialise and shut down the TDA9950 part of the device. These |
255 | * two hooks are provided to allow the TDA998x code to perform those |
256 | * activities. |
257 | */ |
258 | static int tda9950_glue_open(struct tda9950_priv *priv) |
259 | { |
260 | int ret = 0; |
261 | |
262 | if (priv->glue && priv->glue->open) |
263 | ret = priv->glue->open(priv->glue->data); |
264 | |
265 | priv->open = true; |
266 | |
267 | return ret; |
268 | } |
269 | |
270 | static void tda9950_glue_release(struct tda9950_priv *priv) |
271 | { |
272 | priv->open = false; |
273 | |
274 | if (priv->glue && priv->glue->release) |
275 | priv->glue->release(priv->glue->data); |
276 | } |
277 | |
278 | static int tda9950_open(struct tda9950_priv *priv) |
279 | { |
280 | struct i2c_client *client = priv->client; |
281 | int ret; |
282 | |
283 | ret = tda9950_glue_open(priv); |
284 | if (ret) |
285 | return ret; |
286 | |
287 | /* Reset the TDA9950, and wait 250ms for it to recover */ |
288 | tda9950_write(client, addr: REG_CCR, val: CCR_RESET); |
289 | msleep(msecs: 250); |
290 | |
291 | tda9950_cec_adap_log_addr(adap: priv->adap, CEC_LOG_ADDR_INVALID); |
292 | |
293 | /* Start the command processor */ |
294 | tda9950_write(client, addr: REG_CCR, val: CCR_ON); |
295 | |
296 | return 0; |
297 | } |
298 | |
299 | static void tda9950_release(struct tda9950_priv *priv) |
300 | { |
301 | struct i2c_client *client = priv->client; |
302 | int timeout = 50; |
303 | u8 csr; |
304 | |
305 | /* Stop the command processor */ |
306 | tda9950_write(client, addr: REG_CCR, val: 0); |
307 | |
308 | /* Wait up to .5s for it to signal non-busy */ |
309 | do { |
310 | csr = tda9950_read(client, addr: REG_CSR); |
311 | if (!(csr & CSR_BUSY) || !--timeout) |
312 | break; |
313 | msleep(msecs: 10); |
314 | } while (1); |
315 | |
316 | /* Warn the user that their IRQ may die if it's shared. */ |
317 | if (csr & CSR_BUSY) |
318 | dev_warn(&client->dev, "command processor failed to stop, irq%d may die (csr=0x%02x)\n" , |
319 | client->irq, csr); |
320 | |
321 | tda9950_glue_release(priv); |
322 | } |
323 | |
324 | static int tda9950_cec_adap_enable(struct cec_adapter *adap, bool enable) |
325 | { |
326 | struct tda9950_priv *priv = adap->priv; |
327 | |
328 | if (!enable) { |
329 | tda9950_release(priv); |
330 | return 0; |
331 | } else { |
332 | return tda9950_open(priv); |
333 | } |
334 | } |
335 | |
336 | static const struct cec_adap_ops tda9950_cec_ops = { |
337 | .adap_enable = tda9950_cec_adap_enable, |
338 | .adap_log_addr = tda9950_cec_adap_log_addr, |
339 | .adap_transmit = tda9950_cec_transmit, |
340 | }; |
341 | |
342 | /* |
343 | * When operating as part of the TDA998x, we need to claim additional |
344 | * resources. These two hooks permit the management of those resources. |
345 | */ |
346 | static void tda9950_devm_glue_exit(void *data) |
347 | { |
348 | struct tda9950_glue *glue = data; |
349 | |
350 | if (glue && glue->exit) |
351 | glue->exit(glue->data); |
352 | } |
353 | |
354 | static int tda9950_devm_glue_init(struct device *dev, struct tda9950_glue *glue) |
355 | { |
356 | int ret; |
357 | |
358 | if (glue && glue->init) { |
359 | ret = glue->init(glue->data); |
360 | if (ret) |
361 | return ret; |
362 | } |
363 | |
364 | ret = devm_add_action(dev, tda9950_devm_glue_exit, glue); |
365 | if (ret) |
366 | tda9950_devm_glue_exit(data: glue); |
367 | |
368 | return ret; |
369 | } |
370 | |
371 | static void tda9950_cec_del(void *data) |
372 | { |
373 | struct tda9950_priv *priv = data; |
374 | |
375 | cec_delete_adapter(adap: priv->adap); |
376 | } |
377 | |
378 | static int tda9950_probe(struct i2c_client *client) |
379 | { |
380 | struct tda9950_glue *glue = client->dev.platform_data; |
381 | struct device *dev = &client->dev; |
382 | struct tda9950_priv *priv; |
383 | unsigned long irqflags; |
384 | int ret; |
385 | u8 cvr; |
386 | |
387 | /* |
388 | * We must have I2C functionality: our multi-byte accesses |
389 | * must be performed as a single contiguous transaction. |
390 | */ |
391 | if (!i2c_check_functionality(adap: client->adapter, I2C_FUNC_I2C)) { |
392 | dev_err(&client->dev, |
393 | "adapter does not support I2C functionality\n" ); |
394 | return -ENXIO; |
395 | } |
396 | |
397 | /* We must have an interrupt to be functional. */ |
398 | if (client->irq <= 0) { |
399 | dev_err(&client->dev, "driver requires an interrupt\n" ); |
400 | return -ENXIO; |
401 | } |
402 | |
403 | priv = devm_kzalloc(dev, size: sizeof(*priv), GFP_KERNEL); |
404 | if (!priv) |
405 | return -ENOMEM; |
406 | |
407 | priv->client = client; |
408 | priv->glue = glue; |
409 | |
410 | i2c_set_clientdata(client, data: priv); |
411 | |
412 | /* |
413 | * If we're part of a TDA998x, we want the class devices to be |
414 | * associated with the HDMI Tx so we have a tight relationship |
415 | * between the HDMI interface and the CEC interface. |
416 | */ |
417 | priv->hdmi = dev; |
418 | if (glue && glue->parent) |
419 | priv->hdmi = glue->parent; |
420 | |
421 | priv->adap = cec_allocate_adapter(ops: &tda9950_cec_ops, priv, name: "tda9950" , |
422 | CEC_CAP_DEFAULTS | |
423 | CEC_CAP_CONNECTOR_INFO, |
424 | CEC_MAX_LOG_ADDRS); |
425 | if (IS_ERR(ptr: priv->adap)) |
426 | return PTR_ERR(ptr: priv->adap); |
427 | |
428 | ret = devm_add_action(dev, tda9950_cec_del, priv); |
429 | if (ret) { |
430 | cec_delete_adapter(adap: priv->adap); |
431 | return ret; |
432 | } |
433 | |
434 | ret = tda9950_devm_glue_init(dev, glue); |
435 | if (ret) |
436 | return ret; |
437 | |
438 | ret = tda9950_glue_open(priv); |
439 | if (ret) |
440 | return ret; |
441 | |
442 | cvr = tda9950_read(client, addr: REG_CVR); |
443 | |
444 | dev_info(&client->dev, |
445 | "TDA9950 CEC interface, hardware version %u.%u\n" , |
446 | cvr >> 4, cvr & 15); |
447 | |
448 | tda9950_glue_release(priv); |
449 | |
450 | irqflags = IRQF_TRIGGER_FALLING; |
451 | if (glue) |
452 | irqflags = glue->irq_flags; |
453 | |
454 | ret = devm_request_threaded_irq(dev, irq: client->irq, NULL, thread_fn: tda9950_irq, |
455 | irqflags: irqflags | IRQF_SHARED | IRQF_ONESHOT, |
456 | devname: dev_name(dev: &client->dev), dev_id: priv); |
457 | if (ret < 0) |
458 | return ret; |
459 | |
460 | priv->notify = cec_notifier_cec_adap_register(hdmi_dev: priv->hdmi, NULL, |
461 | adap: priv->adap); |
462 | if (!priv->notify) |
463 | return -ENOMEM; |
464 | |
465 | ret = cec_register_adapter(adap: priv->adap, parent: priv->hdmi); |
466 | if (ret < 0) { |
467 | cec_notifier_cec_adap_unregister(n: priv->notify, adap: priv->adap); |
468 | return ret; |
469 | } |
470 | |
471 | /* |
472 | * CEC documentation says we must not call cec_delete_adapter |
473 | * after a successful call to cec_register_adapter(). |
474 | */ |
475 | devm_remove_action(dev, action: tda9950_cec_del, data: priv); |
476 | |
477 | return 0; |
478 | } |
479 | |
480 | static void tda9950_remove(struct i2c_client *client) |
481 | { |
482 | struct tda9950_priv *priv = i2c_get_clientdata(client); |
483 | |
484 | cec_notifier_cec_adap_unregister(n: priv->notify, adap: priv->adap); |
485 | cec_unregister_adapter(adap: priv->adap); |
486 | } |
487 | |
488 | static struct i2c_device_id tda9950_ids[] = { |
489 | { "tda9950" , 0 }, |
490 | { }, |
491 | }; |
492 | MODULE_DEVICE_TABLE(i2c, tda9950_ids); |
493 | |
494 | static struct i2c_driver tda9950_driver = { |
495 | .probe = tda9950_probe, |
496 | .remove = tda9950_remove, |
497 | .driver = { |
498 | .name = "tda9950" , |
499 | }, |
500 | .id_table = tda9950_ids, |
501 | }; |
502 | |
503 | module_i2c_driver(tda9950_driver); |
504 | |
505 | MODULE_AUTHOR("Russell King <rmk+kernel@armlinux.org.uk>" ); |
506 | MODULE_DESCRIPTION("TDA9950/TDA998x Consumer Electronics Control Driver" ); |
507 | MODULE_LICENSE("GPL v2" ); |
508 | |