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(client->adapter, &msg, 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, &val, 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(client->adapter, msg, 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, &val, 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(priv->client, REG_CSR); 149 if (!(csr & CSR_INT)) 150 return IRQ_NONE; 151 152 cconr = tda9950_read(priv->client, REG_CCONR) & CCONR_RETRY_MASK; 153 154 tda9950_read_range(priv->client, REG_CDR0, buf, 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(priv->adap, tx_status, arb_lost_cnt, 194 nack_cnt, 0, 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(priv->adap, &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(priv->client, REG_CCONR, attempts); 229 230 return tda9950_write_range(priv->client, REG_CDR0, buf, 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(priv->client, REG_ACKH, buf, 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, REG_CCR, CCR_RESET); 289 msleep(250); 290 291 tda9950_cec_adap_log_addr(priv->adap, CEC_LOG_ADDR_INVALID); 292 293 /* Start the command processor */ 294 tda9950_write(client, REG_CCR, 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, REG_CCR, 0); 307 308 /* Wait up to .5s for it to signal non-busy */ 309 do { 310 csr = tda9950_read(client, REG_CSR); 311 if (!(csr & CSR_BUSY) || !--timeout) 312 break; 313 msleep(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(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(priv->adap); 376 } 377 378 static int tda9950_probe(struct i2c_client *client, 379 const struct i2c_device_id *id) 380 { 381 struct tda9950_glue *glue = client->dev.platform_data; 382 struct device *dev = &client->dev; 383 struct tda9950_priv *priv; 384 unsigned long irqflags; 385 int ret; 386 u8 cvr; 387 388 /* 389 * We must have I2C functionality: our multi-byte accesses 390 * must be performed as a single contiguous transaction. 391 */ 392 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { 393 dev_err(&client->dev, 394 "adapter does not support I2C functionality\n"); 395 return -ENXIO; 396 } 397 398 /* We must have an interrupt to be functional. */ 399 if (client->irq <= 0) { 400 dev_err(&client->dev, "driver requires an interrupt\n"); 401 return -ENXIO; 402 } 403 404 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); 405 if (!priv) 406 return -ENOMEM; 407 408 priv->client = client; 409 priv->glue = glue; 410 411 i2c_set_clientdata(client, priv); 412 413 /* 414 * If we're part of a TDA998x, we want the class devices to be 415 * associated with the HDMI Tx so we have a tight relationship 416 * between the HDMI interface and the CEC interface. 417 */ 418 priv->hdmi = dev; 419 if (glue && glue->parent) 420 priv->hdmi = glue->parent; 421 422 priv->adap = cec_allocate_adapter(&tda9950_cec_ops, priv, "tda9950", 423 CEC_CAP_DEFAULTS | 424 CEC_CAP_CONNECTOR_INFO, 425 CEC_MAX_LOG_ADDRS); 426 if (IS_ERR(priv->adap)) 427 return PTR_ERR(priv->adap); 428 429 ret = devm_add_action(dev, tda9950_cec_del, priv); 430 if (ret) { 431 cec_delete_adapter(priv->adap); 432 return ret; 433 } 434 435 ret = tda9950_devm_glue_init(dev, glue); 436 if (ret) 437 return ret; 438 439 ret = tda9950_glue_open(priv); 440 if (ret) 441 return ret; 442 443 cvr = tda9950_read(client, REG_CVR); 444 445 dev_info(&client->dev, 446 "TDA9950 CEC interface, hardware version %u.%u\n", 447 cvr >> 4, cvr & 15); 448 449 tda9950_glue_release(priv); 450 451 irqflags = IRQF_TRIGGER_FALLING; 452 if (glue) 453 irqflags = glue->irq_flags; 454 455 ret = devm_request_threaded_irq(dev, client->irq, NULL, tda9950_irq, 456 irqflags | IRQF_SHARED | IRQF_ONESHOT, 457 dev_name(&client->dev), priv); 458 if (ret < 0) 459 return ret; 460 461 priv->notify = cec_notifier_cec_adap_register(priv->hdmi, NULL, 462 priv->adap); 463 if (!priv->notify) 464 return -ENOMEM; 465 466 ret = cec_register_adapter(priv->adap, priv->hdmi); 467 if (ret < 0) { 468 cec_notifier_cec_adap_unregister(priv->notify, priv->adap); 469 return ret; 470 } 471 472 /* 473 * CEC documentation says we must not call cec_delete_adapter 474 * after a successful call to cec_register_adapter(). 475 */ 476 devm_remove_action(dev, tda9950_cec_del, priv); 477 478 return 0; 479 } 480 481 static int tda9950_remove(struct i2c_client *client) 482 { 483 struct tda9950_priv *priv = i2c_get_clientdata(client); 484 485 cec_notifier_cec_adap_unregister(priv->notify, priv->adap); 486 cec_unregister_adapter(priv->adap); 487 488 return 0; 489 } 490 491 static struct i2c_device_id tda9950_ids[] = { 492 { "tda9950", 0 }, 493 { }, 494 }; 495 MODULE_DEVICE_TABLE(i2c, tda9950_ids); 496 497 static struct i2c_driver tda9950_driver = { 498 .probe = tda9950_probe, 499 .remove = tda9950_remove, 500 .driver = { 501 .name = "tda9950", 502 }, 503 .id_table = tda9950_ids, 504 }; 505 506 module_i2c_driver(tda9950_driver); 507 508 MODULE_AUTHOR("Russell King <rmk+kernel@armlinux.org.uk>"); 509 MODULE_DESCRIPTION("TDA9950/TDA998x Consumer Electronics Control Driver"); 510 MODULE_LICENSE("GPL v2"); 511