drm/i2c: tda9950: set MAX_RETRIES for errors only
[sfrench/cifs-2.6.git] / 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[cnt + 1];
80         int ret;
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_MAX_LOG_ADDRS);
425         if (IS_ERR(priv->adap))
426                 return PTR_ERR(priv->adap);
427
428         ret = devm_add_action(dev, tda9950_cec_del, priv);
429         if (ret) {
430                 cec_delete_adapter(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, 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, client->irq, NULL, tda9950_irq,
455                                         irqflags | IRQF_SHARED | IRQF_ONESHOT,
456                                         dev_name(&client->dev), priv);
457         if (ret < 0)
458                 return ret;
459
460         priv->notify = cec_notifier_get(priv->hdmi);
461         if (!priv->notify)
462                 return -ENOMEM;
463
464         ret = cec_register_adapter(priv->adap, priv->hdmi);
465         if (ret < 0) {
466                 cec_notifier_put(priv->notify);
467                 return ret;
468         }
469
470         /*
471          * CEC documentation says we must not call cec_delete_adapter
472          * after a successful call to cec_register_adapter().
473          */
474         devm_remove_action(dev, tda9950_cec_del, priv);
475
476         cec_register_cec_notifier(priv->adap, priv->notify);
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_unregister_adapter(priv->adap);
486         cec_notifier_put(priv->notify);
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");