Linux Audio

Check our new training course

Embedded Linux Audio

Check our new training course
with Creative Commons CC-BY-SA
lecture materials

Bootlin logo

Elixir Cross Referencer

Loading...
  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
// SPDX-License-Identifier: GPL-2.0-only
/*
 *  TDA9950 Consumer Electronics Control driver
 *
 * The NXP TDA9950 implements the HDMI Consumer Electronics Control
 * interface.  The host interface is similar to a mailbox: the data
 * registers starting at REG_CDR0 are written to send a command to the
 * internal CPU, and replies are read from these registers.
 *
 * As the data registers represent a mailbox, they must be accessed
 * as a single I2C transaction.  See the TDA9950 data sheet for details.
 */
#include <linux/delay.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/platform_data/tda9950.h>
#include <linux/slab.h>
#include <drm/drm_edid.h>
#include <media/cec.h>
#include <media/cec-notifier.h>

enum {
	REG_CSR = 0x00,
	CSR_BUSY = BIT(7),
	CSR_INT  = BIT(6),
	CSR_ERR  = BIT(5),

	REG_CER = 0x01,

	REG_CVR = 0x02,

	REG_CCR = 0x03,
	CCR_RESET = BIT(7),
	CCR_ON    = BIT(6),

	REG_ACKH = 0x04,
	REG_ACKL = 0x05,

	REG_CCONR = 0x06,
	CCONR_ENABLE_ERROR = BIT(4),
	CCONR_RETRY_MASK = 7,

	REG_CDR0 = 0x07,

	CDR1_REQ = 0x00,
	CDR1_CNF = 0x01,
	CDR1_IND = 0x81,
	CDR1_ERR = 0x82,
	CDR1_IER = 0x83,

	CDR2_CNF_SUCCESS    = 0x00,
	CDR2_CNF_OFF_STATE  = 0x80,
	CDR2_CNF_BAD_REQ    = 0x81,
	CDR2_CNF_CEC_ACCESS = 0x82,
	CDR2_CNF_ARB_ERROR  = 0x83,
	CDR2_CNF_BAD_TIMING = 0x84,
	CDR2_CNF_NACK_ADDR  = 0x85,
	CDR2_CNF_NACK_DATA  = 0x86,
};

struct tda9950_priv {
	struct i2c_client *client;
	struct device *hdmi;
	struct cec_adapter *adap;
	struct tda9950_glue *glue;
	u16 addresses;
	struct cec_msg rx_msg;
	struct cec_notifier *notify;
	bool open;
};

static int tda9950_write_range(struct i2c_client *client, u8 addr, u8 *p, int cnt)
{
	struct i2c_msg msg;
	u8 buf[CEC_MAX_MSG_SIZE + 3];
	int ret;

	if (WARN_ON(cnt > sizeof(buf) - 1))
		return -EINVAL;

	buf[0] = addr;
	memcpy(buf + 1, p, cnt);

	msg.addr = client->addr;
	msg.flags = 0;
	msg.len = cnt + 1;
	msg.buf = buf;

	dev_dbg(&client->dev, "wr 0x%02x: %*ph\n", addr, cnt, p);

	ret = i2c_transfer(client->adapter, &msg, 1);
	if (ret < 0)
		dev_err(&client->dev, "Error %d writing to cec:0x%x\n", ret, addr);
	return ret < 0 ? ret : 0;
}

static void tda9950_write(struct i2c_client *client, u8 addr, u8 val)
{
	tda9950_write_range(client, addr, &val, 1);
}

static int tda9950_read_range(struct i2c_client *client, u8 addr, u8 *p, int cnt)
{
	struct i2c_msg msg[2];
	int ret;

	msg[0].addr = client->addr;
	msg[0].flags = 0;
	msg[0].len = 1;
	msg[0].buf = &addr;
	msg[1].addr = client->addr;
	msg[1].flags = I2C_M_RD;
	msg[1].len = cnt;
	msg[1].buf = p;

	ret = i2c_transfer(client->adapter, msg, 2);
	if (ret < 0)
		dev_err(&client->dev, "Error %d reading from cec:0x%x\n", ret, addr);

	dev_dbg(&client->dev, "rd 0x%02x: %*ph\n", addr, cnt, p);

	return ret;
}

static u8 tda9950_read(struct i2c_client *client, u8 addr)
{
	int ret;
	u8 val;

	ret = tda9950_read_range(client, addr, &val, 1);
	if (ret < 0)
		val = 0;

	return val;
}

static irqreturn_t tda9950_irq(int irq, void *data)
{
	struct tda9950_priv *priv = data;
	unsigned int tx_status;
	u8 csr, cconr, buf[19];
	u8 arb_lost_cnt, nack_cnt, err_cnt;

	if (!priv->open)
		return IRQ_NONE;

	csr = tda9950_read(priv->client, REG_CSR);
	if (!(csr & CSR_INT))
		return IRQ_NONE;

	cconr = tda9950_read(priv->client, REG_CCONR) & CCONR_RETRY_MASK;

	tda9950_read_range(priv->client, REG_CDR0, buf, sizeof(buf));

	/*
	 * This should never happen: the data sheet says that there will
	 * always be a valid message if the interrupt line is asserted.
	 */
	if (buf[0] == 0) {
		dev_warn(&priv->client->dev, "interrupt pending, but no message?\n");
		return IRQ_NONE;
	}

	switch (buf[1]) {
	case CDR1_CNF: /* transmit result */
		arb_lost_cnt = nack_cnt = err_cnt = 0;
		switch (buf[2]) {
		case CDR2_CNF_SUCCESS:
			tx_status = CEC_TX_STATUS_OK;
			break;

		case CDR2_CNF_ARB_ERROR:
			tx_status = CEC_TX_STATUS_ARB_LOST;
			arb_lost_cnt = cconr;
			break;

		case CDR2_CNF_NACK_ADDR:
			tx_status = CEC_TX_STATUS_NACK;
			nack_cnt = cconr;
			break;

		default: /* some other error, refer to TDA9950 docs */
			dev_err(&priv->client->dev, "CNF reply error 0x%02x\n",
				buf[2]);
			tx_status = CEC_TX_STATUS_ERROR;
			err_cnt = cconr;
			break;
		}
		/* TDA9950 executes all retries for us */
		if (tx_status != CEC_TX_STATUS_OK)
			tx_status |= CEC_TX_STATUS_MAX_RETRIES;
		cec_transmit_done(priv->adap, tx_status, arb_lost_cnt,
				  nack_cnt, 0, err_cnt);
		break;

	case CDR1_IND:
		priv->rx_msg.len = buf[0] - 2;
		if (priv->rx_msg.len > CEC_MAX_MSG_SIZE)
			priv->rx_msg.len = CEC_MAX_MSG_SIZE;

		memcpy(priv->rx_msg.msg, buf + 2, priv->rx_msg.len);
		cec_received_msg(priv->adap, &priv->rx_msg);
		break;

	default: /* unknown */
		dev_err(&priv->client->dev, "unknown service id 0x%02x\n",
			buf[1]);
		break;
	}

	return IRQ_HANDLED;
}

static int tda9950_cec_transmit(struct cec_adapter *adap, u8 attempts,
				u32 signal_free_time, struct cec_msg *msg)
{
	struct tda9950_priv *priv = adap->priv;
	u8 buf[CEC_MAX_MSG_SIZE + 2];

	buf[0] = 2 + msg->len;
	buf[1] = CDR1_REQ;
	memcpy(buf + 2, msg->msg, msg->len);

	if (attempts > 5)
		attempts = 5;

	tda9950_write(priv->client, REG_CCONR, attempts);

	return tda9950_write_range(priv->client, REG_CDR0, buf, 2 + msg->len);
}

static int tda9950_cec_adap_log_addr(struct cec_adapter *adap, u8 addr)
{
	struct tda9950_priv *priv = adap->priv;
	u16 addresses;
	u8 buf[2];

	if (addr == CEC_LOG_ADDR_INVALID)
		addresses = priv->addresses = 0;
	else
		addresses = priv->addresses |= BIT(addr);

	/* TDA9950 doesn't want address 15 set */
	addresses &= 0x7fff;
	buf[0] = addresses >> 8;
	buf[1] = addresses;

	return tda9950_write_range(priv->client, REG_ACKH, buf, 2);
}

/*
 * When operating as part of the TDA998x, we need additional handling
 * to initialise and shut down the TDA9950 part of the device.  These
 * two hooks are provided to allow the TDA998x code to perform those
 * activities.
 */
static int tda9950_glue_open(struct tda9950_priv *priv)
{
	int ret = 0;

	if (priv->glue && priv->glue->open)
		ret = priv->glue->open(priv->glue->data);

	priv->open = true;

	return ret;
}

static void tda9950_glue_release(struct tda9950_priv *priv)
{
	priv->open = false;

	if (priv->glue && priv->glue->release)
		priv->glue->release(priv->glue->data);
}

static int tda9950_open(struct tda9950_priv *priv)
{
	struct i2c_client *client = priv->client;
	int ret;

	ret = tda9950_glue_open(priv);
	if (ret)
		return ret;

	/* Reset the TDA9950, and wait 250ms for it to recover */
	tda9950_write(client, REG_CCR, CCR_RESET);
	msleep(250);

	tda9950_cec_adap_log_addr(priv->adap, CEC_LOG_ADDR_INVALID);

	/* Start the command processor */
	tda9950_write(client, REG_CCR, CCR_ON);

	return 0;
}

static void tda9950_release(struct tda9950_priv *priv)
{
	struct i2c_client *client = priv->client;
	int timeout = 50;
	u8 csr;

	/* Stop the command processor */
	tda9950_write(client, REG_CCR, 0);

	/* Wait up to .5s for it to signal non-busy */
	do {
		csr = tda9950_read(client, REG_CSR);
		if (!(csr & CSR_BUSY) || !--timeout)
			break;
		msleep(10);
	} while (1);

	/* Warn the user that their IRQ may die if it's shared. */
	if (csr & CSR_BUSY)
		dev_warn(&client->dev, "command processor failed to stop, irq%d may die (csr=0x%02x)\n",
			 client->irq, csr);

	tda9950_glue_release(priv);
}

static int tda9950_cec_adap_enable(struct cec_adapter *adap, bool enable)
{
	struct tda9950_priv *priv = adap->priv;

	if (!enable) {
		tda9950_release(priv);
		return 0;
	} else {
		return tda9950_open(priv);
	}
}

static const struct cec_adap_ops tda9950_cec_ops = {
	.adap_enable = tda9950_cec_adap_enable,
	.adap_log_addr = tda9950_cec_adap_log_addr,
	.adap_transmit = tda9950_cec_transmit,
};

/*
 * When operating as part of the TDA998x, we need to claim additional
 * resources.  These two hooks permit the management of those resources.
 */
static void tda9950_devm_glue_exit(void *data)
{
	struct tda9950_glue *glue = data;

	if (glue && glue->exit)
		glue->exit(glue->data);
}

static int tda9950_devm_glue_init(struct device *dev, struct tda9950_glue *glue)
{
	int ret;

	if (glue && glue->init) {
		ret = glue->init(glue->data);
		if (ret)
			return ret;
	}

	ret = devm_add_action(dev, tda9950_devm_glue_exit, glue);
	if (ret)
		tda9950_devm_glue_exit(glue);

	return ret;
}

static void tda9950_cec_del(void *data)
{
	struct tda9950_priv *priv = data;

	cec_delete_adapter(priv->adap);
}

static int tda9950_probe(struct i2c_client *client,
			 const struct i2c_device_id *id)
{
	struct tda9950_glue *glue = client->dev.platform_data;
	struct device *dev = &client->dev;
	struct tda9950_priv *priv;
	unsigned long irqflags;
	int ret;
	u8 cvr;

	/*
	 * We must have I2C functionality: our multi-byte accesses
	 * must be performed as a single contiguous transaction.
	 */
	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
		dev_err(&client->dev,
			"adapter does not support I2C functionality\n");
		return -ENXIO;
	}

	/* We must have an interrupt to be functional. */
	if (client->irq <= 0) {
		dev_err(&client->dev, "driver requires an interrupt\n");
		return -ENXIO;
	}

	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
	if (!priv)
		return -ENOMEM;

	priv->client = client;
	priv->glue = glue;

	i2c_set_clientdata(client, priv);

	/*
	 * If we're part of a TDA998x, we want the class devices to be
	 * associated with the HDMI Tx so we have a tight relationship
	 * between the HDMI interface and the CEC interface.
	 */
	priv->hdmi = dev;
	if (glue && glue->parent)
		priv->hdmi = glue->parent;

	priv->adap = cec_allocate_adapter(&tda9950_cec_ops, priv, "tda9950",
					  CEC_CAP_DEFAULTS,
					  CEC_MAX_LOG_ADDRS);
	if (IS_ERR(priv->adap))
		return PTR_ERR(priv->adap);

	ret = devm_add_action(dev, tda9950_cec_del, priv);
	if (ret) {
		cec_delete_adapter(priv->adap);
		return ret;
	}

	ret = tda9950_devm_glue_init(dev, glue);
	if (ret)
		return ret;

	ret = tda9950_glue_open(priv);
	if (ret)
		return ret;

	cvr = tda9950_read(client, REG_CVR);

	dev_info(&client->dev,
		 "TDA9950 CEC interface, hardware version %u.%u\n",
		 cvr >> 4, cvr & 15);

	tda9950_glue_release(priv);

	irqflags = IRQF_TRIGGER_FALLING;
	if (glue)
		irqflags = glue->irq_flags;

	ret = devm_request_threaded_irq(dev, client->irq, NULL, tda9950_irq,
					irqflags | IRQF_SHARED | IRQF_ONESHOT,
					dev_name(&client->dev), priv);
	if (ret < 0)
		return ret;

	priv->notify = cec_notifier_get(priv->hdmi);
	if (!priv->notify)
		return -ENOMEM;

	ret = cec_register_adapter(priv->adap, priv->hdmi);
	if (ret < 0) {
		cec_notifier_put(priv->notify);
		return ret;
	}

	/*
	 * CEC documentation says we must not call cec_delete_adapter
	 * after a successful call to cec_register_adapter().
	 */
	devm_remove_action(dev, tda9950_cec_del, priv);

	cec_register_cec_notifier(priv->adap, priv->notify);

	return 0;
}

static int tda9950_remove(struct i2c_client *client)
{
	struct tda9950_priv *priv = i2c_get_clientdata(client);

	cec_unregister_adapter(priv->adap);
	cec_notifier_put(priv->notify);

	return 0;
}

static struct i2c_device_id tda9950_ids[] = {
	{ "tda9950", 0 },
	{ },
};
MODULE_DEVICE_TABLE(i2c, tda9950_ids);

static struct i2c_driver tda9950_driver = {
	.probe = tda9950_probe,
	.remove = tda9950_remove,
	.driver = {
		.name = "tda9950",
	},
	.id_table = tda9950_ids,
};

module_i2c_driver(tda9950_driver);

MODULE_AUTHOR("Russell King <rmk+kernel@armlinux.org.uk>");
MODULE_DESCRIPTION("TDA9950/TDA998x Consumer Electronics Control Driver");
MODULE_LICENSE("GPL v2");