drivers/gpu/drm/i2c/tda9950.c

   1 /*
   2  *  TDA9950 Consumer Electronics Control driver
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  *
   8  * The NXP TDA9950 implements the HDMI Consumer Electronics Control
   9  * interface.  The host interface is similar to a mailbox: the data
  10  * registers starting at REG_CDR0 are written to send a command to the
  11  * internal CPU, and replies are read from these registers.
  12  *
  13  * As the data registers represent a mailbox, they must be accessed
  14  * as a single I2C transaction.  See the TDA9950 data sheet for details.
  15  */
  16 #include <linux/delay.h>
  17 #include <linux/i2c.h>
  18 #include <linux/interrupt.h>
  19 #include <linux/module.h>
  20 #include <linux/platform_data/tda9950.h>
  21 #include <linux/slab.h>
  22 #include <drm/drm_edid.h>
  23 #include <media/cec.h>
  24 #include <media/cec-notifier.h>
  25
  26 enum {
  27         REG_CSR = 0x00,
  28         CSR_BUSY = BIT(7),
  29         CSR_INT  = BIT(6),
  30         CSR_ERR  = BIT(5),
  31
  32         REG_CER = 0x01,
  33
  34         REG_CVR = 0x02,
  35
  36         REG_CCR = 0x03,
  37         CCR_RESET = BIT(7),
  38         CCR_ON    = BIT(6),
  39
  40         REG_ACKH = 0x04,
  41         REG_ACKL = 0x05,
  42
  43         REG_CCONR = 0x06,
  44         CCONR_ENABLE_ERROR = BIT(4),
  45         CCONR_RETRY_MASK = 7,
  46
  47         REG_CDR0 = 0x07,
  48
  49         CDR1_REQ = 0x00,
  50         CDR1_CNF = 0x01,
  51         CDR1_IND = 0x81,
  52         CDR1_ERR = 0x82,
  53         CDR1_IER = 0x83,
  54
  55         CDR2_CNF_SUCCESS    = 0x00,
  56         CDR2_CNF_OFF_STATE  = 0x80,
  57         CDR2_CNF_BAD_REQ    = 0x81,
  58         CDR2_CNF_CEC_ACCESS = 0x82,
  59         CDR2_CNF_ARB_ERROR  = 0x83,
  60         CDR2_CNF_BAD_TIMING = 0x84,
  61         CDR2_CNF_NACK_ADDR  = 0x85,
  62         CDR2_CNF_NACK_DATA  = 0x86,
  63 };
  64
  65 struct tda9950_priv {
  66         struct i2c_client *client;
  67         struct device *hdmi;
  68         struct cec_adapter *adap;
  69         struct tda9950_glue *glue;
  70         u16 addresses;
  71         struct cec_msg rx_msg;
  72         struct cec_notifier *notify;
  73         bool open;
  74 };
  75
  76 static int tda9950_write_range(struct i2c_client *client, u8 addr, u8 *p, int cnt)
  77 {
  78         struct i2c_msg msg;
  79         u8 buf[CEC_MAX_MSG_SIZE + 3];
  80         int ret;
  81
  82         if (WARN_ON(cnt > sizeof(buf) - 1))
  83                 return -EINVAL;
  84
  85         buf[0] = addr;
  86         memcpy(buf + 1, p, cnt);
  87
  88         msg.addr = client->addr;
  89         msg.flags = 0;
  90         msg.len = cnt + 1;
  91         msg.buf = buf;
  92
  93         dev_dbg(&client->dev, "wr 0x%02x: %*ph\n", addr, cnt, p);
  94
  95         ret = i2c_transfer(client->adapter, &msg, 1);
  96         if (ret < 0)
  97                 dev_err(&client->dev, "Error %d writing to cec:0x%x\n", ret, addr);
  98         return ret < 0 ? ret : 0;
  99 }
 100
 101 static void tda9950_write(struct i2c_client *client, u8 addr, u8 val)
 102 {
 103         tda9950_write_range(client, addr, &val, 1);
 104 }
 105
 106 static int tda9950_read_range(struct i2c_client *client, u8 addr, u8 *p, int cnt)
 107 {
 108         struct i2c_msg msg[2];
 109         int ret;
 110
 111         msg[0].addr = client->addr;
 112         msg[0].flags = 0;
 113         msg[0].len = 1;
 114         msg[0].buf = &addr;
 115         msg[1].addr = client->addr;
 116         msg[1].flags = I2C_M_RD;
 117         msg[1].len = cnt;
 118         msg[1].buf = p;
 119
 120         ret = i2c_transfer(client->adapter, msg, 2);
 121         if (ret < 0)
 122                 dev_err(&client->dev, "Error %d reading from cec:0x%x\n", ret, addr);
 123
 124         dev_dbg(&client->dev, "rd 0x%02x: %*ph\n", addr, cnt, p);
 125
 126         return ret;
 127 }
 128
 129 static u8 tda9950_read(struct i2c_client *client, u8 addr)
 130 {
 131         int ret;
 132         u8 val;
 133
 134         ret = tda9950_read_range(client, addr, &val, 1);
 135         if (ret < 0)
 136                 val = 0;
 137
 138         return val;
 139 }
 140
 141 static irqreturn_t tda9950_irq(int irq, void *data)
 142 {
 143         struct tda9950_priv *priv = data;
 144         unsigned int tx_status;
 145         u8 csr, cconr, buf[19];
 146         u8 arb_lost_cnt, nack_cnt, err_cnt;
 147
 148         if (!priv->open)
 149                 return IRQ_NONE;
 150
 151         csr = tda9950_read(priv->client, REG_CSR);
 152         if (!(csr & CSR_INT))
 153                 return IRQ_NONE;
 154
 155         cconr = tda9950_read(priv->client, REG_CCONR) & CCONR_RETRY_MASK;
 156
 157         tda9950_read_range(priv->client, REG_CDR0, buf, sizeof(buf));
 158
 159         /*
 160          * This should never happen: the data sheet says that there will
 161          * always be a valid message if the interrupt line is asserted.
 162          */
 163         if (buf[0] == 0) {
 164                 dev_warn(&priv->client->dev, "interrupt pending, but no message?\n");
 165                 return IRQ_NONE;
 166         }
 167
 168         switch (buf[1]) {
 169         case CDR1_CNF: /* transmit result */
 170                 arb_lost_cnt = nack_cnt = err_cnt = 0;
 171                 switch (buf[2]) {
 172                 case CDR2_CNF_SUCCESS:
 173                         tx_status = CEC_TX_STATUS_OK;
 174                         break;
 175
 176                 case CDR2_CNF_ARB_ERROR:
 177                         tx_status = CEC_TX_STATUS_ARB_LOST;
 178                         arb_lost_cnt = cconr;
 179                         break;
 180
 181                 case CDR2_CNF_NACK_ADDR:
 182                         tx_status = CEC_TX_STATUS_NACK;
 183                         nack_cnt = cconr;
 184                         break;
 185
 186                 default: /* some other error, refer to TDA9950 docs */
 187                         dev_err(&priv->client->dev, "CNF reply error 0x%02x\n",
 188                                 buf[2]);
 189                         tx_status = CEC_TX_STATUS_ERROR;
 190                         err_cnt = cconr;
 191                         break;
 192                 }
 193                 /* TDA9950 executes all retries for us */
 194                 if (tx_status != CEC_TX_STATUS_OK)
 195                         tx_status |= CEC_TX_STATUS_MAX_RETRIES;
 196                 cec_transmit_done(priv->adap, tx_status, arb_lost_cnt,
 197                                   nack_cnt, 0, err_cnt);
 198                 break;
 199
 200         case CDR1_IND:
 201                 priv->rx_msg.len = buf[0] - 2;
 202                 if (priv->rx_msg.len > CEC_MAX_MSG_SIZE)
 203                         priv->rx_msg.len = CEC_MAX_MSG_SIZE;
 204
 205                 memcpy(priv->rx_msg.msg, buf + 2, priv->rx_msg.len);
 206                 cec_received_msg(priv->adap, &priv->rx_msg);
 207                 break;
 208
 209         default: /* unknown */
 210                 dev_err(&priv->client->dev, "unknown service id 0x%02x\n",
 211                         buf[1]);
 212                 break;
 213         }
 214
 215         return IRQ_HANDLED;
 216 }
 217
 218 static int tda9950_cec_transmit(struct cec_adapter *adap, u8 attempts,
 219                                 u32 signal_free_time, struct cec_msg *msg)
 220 {
 221         struct tda9950_priv *priv = adap->priv;
 222         u8 buf[CEC_MAX_MSG_SIZE + 2];
 223
 224         buf[0] = 2 + msg->len;
 225         buf[1] = CDR1_REQ;
 226         memcpy(buf + 2, msg->msg, msg->len);
 227
 228         if (attempts > 5)
 229                 attempts = 5;
 230
 231         tda9950_write(priv->client, REG_CCONR, attempts);
 232
 233         return tda9950_write_range(priv->client, REG_CDR0, buf, 2 + msg->len);
 234 }
 235
 236 static int tda9950_cec_adap_log_addr(struct cec_adapter *adap, u8 addr)
 237 {
 238         struct tda9950_priv *priv = adap->priv;
 239         u16 addresses;
 240         u8 buf[2];
 241
 242         if (addr == CEC_LOG_ADDR_INVALID)
 243                 addresses = priv->addresses = 0;
 244         else
 245                 addresses = priv->addresses |= BIT(addr);
 246
 247         /* TDA9950 doesn't want address 15 set */
 248         addresses &= 0x7fff;
 249         buf[0] = addresses >> 8;
 250         buf[1] = addresses;
 251
 252         return tda9950_write_range(priv->client, REG_ACKH, buf, 2);
 253 }
 254
 255 /*
 256  * When operating as part of the TDA998x, we need additional handling
 257  * to initialise and shut down the TDA9950 part of the device.  These
 258  * two hooks are provided to allow the TDA998x code to perform those
 259  * activities.
 260  */
 261 static int tda9950_glue_open(struct tda9950_priv *priv)
 262 {
 263         int ret = 0;
 264
 265         if (priv->glue && priv->glue->open)
 266                 ret = priv->glue->open(priv->glue->data);
 267
 268         priv->open = true;
 269
 270         return ret;
 271 }
 272
 273 static void tda9950_glue_release(struct tda9950_priv *priv)
 274 {
 275         priv->open = false;
 276
 277         if (priv->glue && priv->glue->release)
 278                 priv->glue->release(priv->glue->data);
 279 }
 280
 281 static int tda9950_open(struct tda9950_priv *priv)
 282 {
 283         struct i2c_client *client = priv->client;
 284         int ret;
 285
 286         ret = tda9950_glue_open(priv);
 287         if (ret)
 288                 return ret;
 289
 290         /* Reset the TDA9950, and wait 250ms for it to recover */
 291         tda9950_write(client, REG_CCR, CCR_RESET);
 292         msleep(250);
 293
 294         tda9950_cec_adap_log_addr(priv->adap, CEC_LOG_ADDR_INVALID);
 295
 296         /* Start the command processor */
 297         tda9950_write(client, REG_CCR, CCR_ON);
 298
 299         return 0;
 300 }
 301
 302 static void tda9950_release(struct tda9950_priv *priv)
 303 {
 304         struct i2c_client *client = priv->client;
 305         int timeout = 50;
 306         u8 csr;
 307
 308         /* Stop the command processor */
 309         tda9950_write(client, REG_CCR, 0);
 310
 311         /* Wait up to .5s for it to signal non-busy */
 312         do {
 313                 csr = tda9950_read(client, REG_CSR);
 314                 if (!(csr & CSR_BUSY) || !--timeout)
 315                         break;
 316                 msleep(10);
 317         } while (1);
 318
 319         /* Warn the user that their IRQ may die if it's shared. */
 320         if (csr & CSR_BUSY)
 321                 dev_warn(&client->dev, "command processor failed to stop, irq%d may die (csr=0x%02x)\n",
 322                          client->irq, csr);
 323
 324         tda9950_glue_release(priv);
 325 }
 326
 327 static int tda9950_cec_adap_enable(struct cec_adapter *adap, bool enable)
 328 {
 329         struct tda9950_priv *priv = adap->priv;
 330
 331         if (!enable) {
 332                 tda9950_release(priv);
 333                 return 0;
 334         } else {
 335                 return tda9950_open(priv);
 336         }
 337 }
 338
 339 static const struct cec_adap_ops tda9950_cec_ops = {
 340         .adap_enable = tda9950_cec_adap_enable,
 341         .adap_log_addr = tda9950_cec_adap_log_addr,
 342         .adap_transmit = tda9950_cec_transmit,
 343 };
 344
 345 /*
 346  * When operating as part of the TDA998x, we need to claim additional
 347  * resources.  These two hooks permit the management of those resources.
 348  */
 349 static void tda9950_devm_glue_exit(void *data)
 350 {
 351         struct tda9950_glue *glue = data;
 352
 353         if (glue && glue->exit)
 354                 glue->exit(glue->data);
 355 }
 356
 357 static int tda9950_devm_glue_init(struct device *dev, struct tda9950_glue *glue)
 358 {
 359         int ret;
 360
 361         if (glue && glue->init) {
 362                 ret = glue->init(glue->data);
 363                 if (ret)
 364                         return ret;
 365         }
 366
 367         ret = devm_add_action(dev, tda9950_devm_glue_exit, glue);
 368         if (ret)
 369                 tda9950_devm_glue_exit(glue);
 370
 371         return ret;
 372 }
 373
 374 static void tda9950_cec_del(void *data)
 375 {
 376         struct tda9950_priv *priv = data;
 377
 378         cec_delete_adapter(priv->adap);
 379 }
 380
 381 static int tda9950_probe(struct i2c_client *client,
 382                          const struct i2c_device_id *id)
 383 {
 384         struct tda9950_glue *glue = client->dev.platform_data;
 385         struct device *dev = &client->dev;
 386         struct tda9950_priv *priv;
 387         unsigned long irqflags;
 388         int ret;
 389         u8 cvr;
 390
 391         /*
 392          * We must have I2C functionality: our multi-byte accesses
 393          * must be performed as a single contiguous transaction.
 394          */
 395         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
 396                 dev_err(&client->dev,
 397                         "adapter does not support I2C functionality\n");
 398                 return -ENXIO;
 399         }
 400
 401         /* We must have an interrupt to be functional. */
 402         if (client->irq <= 0) {
 403                 dev_err(&client->dev, "driver requires an interrupt\n");
 404                 return -ENXIO;
 405         }
 406
 407         priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
 408         if (!priv)
 409                 return -ENOMEM;
 410
 411         priv->client = client;
 412         priv->glue = glue;
 413
 414         i2c_set_clientdata(client, priv);
 415
 416         /*
 417          * If we're part of a TDA998x, we want the class devices to be
 418          * associated with the HDMI Tx so we have a tight relationship
 419          * between the HDMI interface and the CEC interface.
 420          */
 421         priv->hdmi = dev;
 422         if (glue && glue->parent)
 423                 priv->hdmi = glue->parent;
 424
 425         priv->adap = cec_allocate_adapter(&tda9950_cec_ops, priv, "tda9950",
 426                                           CEC_CAP_DEFAULTS,
 427                                           CEC_MAX_LOG_ADDRS);
 428         if (IS_ERR(priv->adap))
 429                 return PTR_ERR(priv->adap);
 430
 431         ret = devm_add_action(dev, tda9950_cec_del, priv);
 432         if (ret) {
 433                 cec_delete_adapter(priv->adap);
 434                 return ret;
 435         }
 436
 437         ret = tda9950_devm_glue_init(dev, glue);
 438         if (ret)
 439                 return ret;
 440
 441         ret = tda9950_glue_open(priv);
 442         if (ret)
 443                 return ret;
 444
 445         cvr = tda9950_read(client, REG_CVR);
 446
 447         dev_info(&client->dev,
 448                  "TDA9950 CEC interface, hardware version %u.%u\n",
 449                  cvr >> 4, cvr & 15);
 450
 451         tda9950_glue_release(priv);
 452
 453         irqflags = IRQF_TRIGGER_FALLING;
 454         if (glue)
 455                 irqflags = glue->irq_flags;
 456
 457         ret = devm_request_threaded_irq(dev, client->irq, NULL, tda9950_irq,
 458                                         irqflags | IRQF_SHARED | IRQF_ONESHOT,
 459                                         dev_name(&client->dev), priv);
 460         if (ret < 0)
 461                 return ret;
 462
 463         priv->notify = cec_notifier_get(priv->hdmi);
 464         if (!priv->notify)
 465                 return -ENOMEM;
 466
 467         ret = cec_register_adapter(priv->adap, priv->hdmi);
 468         if (ret < 0) {
 469                 cec_notifier_put(priv->notify);
 470                 return ret;
 471         }
 472
 473         /*
 474          * CEC documentation says we must not call cec_delete_adapter
 475          * after a successful call to cec_register_adapter().
 476          */
 477         devm_remove_action(dev, tda9950_cec_del, priv);
 478
 479         cec_register_cec_notifier(priv->adap, priv->notify);
 480
 481         return 0;
 482 }
 483
 484 static int tda9950_remove(struct i2c_client *client)
 485 {
 486         struct tda9950_priv *priv = i2c_get_clientdata(client);
 487
 488         cec_unregister_adapter(priv->adap);
 489         cec_notifier_put(priv->notify);
 490
 491         return 0;
 492 }
 493
 494 static struct i2c_device_id tda9950_ids[] = {
 495         { "tda9950", 0 },
 496         { },
 497 };
 498 MODULE_DEVICE_TABLE(i2c, tda9950_ids);
 499
 500 static struct i2c_driver tda9950_driver = {
 501         .probe = tda9950_probe,
 502         .remove = tda9950_remove,
 503         .driver = {
 504                 .name = "tda9950",
 505         },
 506         .id_table = tda9950_ids,
 507 };
 508
 509 module_i2c_driver(tda9950_driver);
 510
 511 MODULE_AUTHOR("Russell King <rmk+kernel@armlinux.org.uk>");
 512 MODULE_DESCRIPTION("TDA9950/TDA998x Consumer Electronics Control Driver");
 513 MODULE_LICENSE("GPL v2");