Merge tag 'drm-intel-fixes-2018-10-03' of git://anongit.freedesktop.org/drm/drm-intel...
[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[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                 tx_status |= CEC_TX_STATUS_MAX_RETRIES;
195                 cec_transmit_done(priv->adap, tx_status, arb_lost_cnt,
196                                   nack_cnt, 0, err_cnt);
197                 break;
198
199         case CDR1_IND:
200                 priv->rx_msg.len = buf[0] - 2;
201                 if (priv->rx_msg.len > CEC_MAX_MSG_SIZE)
202                         priv->rx_msg.len = CEC_MAX_MSG_SIZE;
203
204                 memcpy(priv->rx_msg.msg, buf + 2, priv->rx_msg.len);
205                 cec_received_msg(priv->adap, &priv->rx_msg);
206                 break;
207
208         default: /* unknown */
209                 dev_err(&priv->client->dev, "unknown service id 0x%02x\n",
210                         buf[1]);
211                 break;
212         }
213
214         return IRQ_HANDLED;
215 }
216
217 static int tda9950_cec_transmit(struct cec_adapter *adap, u8 attempts,
218                                 u32 signal_free_time, struct cec_msg *msg)
219 {
220         struct tda9950_priv *priv = adap->priv;
221         u8 buf[CEC_MAX_MSG_SIZE + 2];
222
223         buf[0] = 2 + msg->len;
224         buf[1] = CDR1_REQ;
225         memcpy(buf + 2, msg->msg, msg->len);
226
227         if (attempts > 5)
228                 attempts = 5;
229
230         tda9950_write(priv->client, REG_CCONR, attempts);
231
232         return tda9950_write_range(priv->client, REG_CDR0, buf, 2 + msg->len);
233 }
234
235 static int tda9950_cec_adap_log_addr(struct cec_adapter *adap, u8 addr)
236 {
237         struct tda9950_priv *priv = adap->priv;
238         u16 addresses;
239         u8 buf[2];
240
241         if (addr == CEC_LOG_ADDR_INVALID)
242                 addresses = priv->addresses = 0;
243         else
244                 addresses = priv->addresses |= BIT(addr);
245
246         /* TDA9950 doesn't want address 15 set */
247         addresses &= 0x7fff;
248         buf[0] = addresses >> 8;
249         buf[1] = addresses;
250
251         return tda9950_write_range(priv->client, REG_ACKH, buf, 2);
252 }
253
254 /*
255  * When operating as part of the TDA998x, we need additional handling
256  * to initialise and shut down the TDA9950 part of the device.  These
257  * two hooks are provided to allow the TDA998x code to perform those
258  * activities.
259  */
260 static int tda9950_glue_open(struct tda9950_priv *priv)
261 {
262         int ret = 0;
263
264         if (priv->glue && priv->glue->open)
265                 ret = priv->glue->open(priv->glue->data);
266
267         priv->open = true;
268
269         return ret;
270 }
271
272 static void tda9950_glue_release(struct tda9950_priv *priv)
273 {
274         priv->open = false;
275
276         if (priv->glue && priv->glue->release)
277                 priv->glue->release(priv->glue->data);
278 }
279
280 static int tda9950_open(struct tda9950_priv *priv)
281 {
282         struct i2c_client *client = priv->client;
283         int ret;
284
285         ret = tda9950_glue_open(priv);
286         if (ret)
287                 return ret;
288
289         /* Reset the TDA9950, and wait 250ms for it to recover */
290         tda9950_write(client, REG_CCR, CCR_RESET);
291         msleep(250);
292
293         tda9950_cec_adap_log_addr(priv->adap, CEC_LOG_ADDR_INVALID);
294
295         /* Start the command processor */
296         tda9950_write(client, REG_CCR, CCR_ON);
297
298         return 0;
299 }
300
301 static void tda9950_release(struct tda9950_priv *priv)
302 {
303         struct i2c_client *client = priv->client;
304         int timeout = 50;
305         u8 csr;
306
307         /* Stop the command processor */
308         tda9950_write(client, REG_CCR, 0);
309
310         /* Wait up to .5s for it to signal non-busy */
311         do {
312                 csr = tda9950_read(client, REG_CSR);
313                 if (!(csr & CSR_BUSY) || --timeout)
314                         break;
315                 msleep(10);
316         } while (1);
317
318         /* Warn the user that their IRQ may die if it's shared. */
319         if (csr & CSR_BUSY)
320                 dev_warn(&client->dev, "command processor failed to stop, irq%d may die (csr=0x%02x)\n",
321                          client->irq, csr);
322
323         tda9950_glue_release(priv);
324 }
325
326 static int tda9950_cec_adap_enable(struct cec_adapter *adap, bool enable)
327 {
328         struct tda9950_priv *priv = adap->priv;
329
330         if (!enable) {
331                 tda9950_release(priv);
332                 return 0;
333         } else {
334                 return tda9950_open(priv);
335         }
336 }
337
338 static const struct cec_adap_ops tda9950_cec_ops = {
339         .adap_enable = tda9950_cec_adap_enable,
340         .adap_log_addr = tda9950_cec_adap_log_addr,
341         .adap_transmit = tda9950_cec_transmit,
342 };
343
344 /*
345  * When operating as part of the TDA998x, we need to claim additional
346  * resources.  These two hooks permit the management of those resources.
347  */
348 static void tda9950_devm_glue_exit(void *data)
349 {
350         struct tda9950_glue *glue = data;
351
352         if (glue && glue->exit)
353                 glue->exit(glue->data);
354 }
355
356 static int tda9950_devm_glue_init(struct device *dev, struct tda9950_glue *glue)
357 {
358         int ret;
359
360         if (glue && glue->init) {
361                 ret = glue->init(glue->data);
362                 if (ret)
363                         return ret;
364         }
365
366         ret = devm_add_action(dev, tda9950_devm_glue_exit, glue);
367         if (ret)
368                 tda9950_devm_glue_exit(glue);
369
370         return ret;
371 }
372
373 static void tda9950_cec_del(void *data)
374 {
375         struct tda9950_priv *priv = data;
376
377         cec_delete_adapter(priv->adap);
378 }
379
380 static int tda9950_probe(struct i2c_client *client,
381                          const struct i2c_device_id *id)
382 {
383         struct tda9950_glue *glue = client->dev.platform_data;
384         struct device *dev = &client->dev;
385         struct tda9950_priv *priv;
386         unsigned long irqflags;
387         int ret;
388         u8 cvr;
389
390         /*
391          * We must have I2C functionality: our multi-byte accesses
392          * must be performed as a single contiguous transaction.
393          */
394         if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
395                 dev_err(&client->dev,
396                         "adapter does not support I2C functionality\n");
397                 return -ENXIO;
398         }
399
400         /* We must have an interrupt to be functional. */
401         if (client->irq <= 0) {
402                 dev_err(&client->dev, "driver requires an interrupt\n");
403                 return -ENXIO;
404         }
405
406         priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
407         if (!priv)
408                 return -ENOMEM;
409
410         priv->client = client;
411         priv->glue = glue;
412
413         i2c_set_clientdata(client, priv);
414
415         /*
416          * If we're part of a TDA998x, we want the class devices to be
417          * associated with the HDMI Tx so we have a tight relationship
418          * between the HDMI interface and the CEC interface.
419          */
420         priv->hdmi = dev;
421         if (glue && glue->parent)
422                 priv->hdmi = glue->parent;
423
424         priv->adap = cec_allocate_adapter(&tda9950_cec_ops, priv, "tda9950",
425                                           CEC_CAP_DEFAULTS,
426                                           CEC_MAX_LOG_ADDRS);
427         if (IS_ERR(priv->adap))
428                 return PTR_ERR(priv->adap);
429
430         ret = devm_add_action(dev, tda9950_cec_del, priv);
431         if (ret) {
432                 cec_delete_adapter(priv->adap);
433                 return ret;
434         }
435
436         ret = tda9950_devm_glue_init(dev, glue);
437         if (ret)
438                 return ret;
439
440         ret = tda9950_glue_open(priv);
441         if (ret)
442                 return ret;
443
444         cvr = tda9950_read(client, REG_CVR);
445
446         dev_info(&client->dev,
447                  "TDA9950 CEC interface, hardware version %u.%u\n",
448                  cvr >> 4, cvr & 15);
449
450         tda9950_glue_release(priv);
451
452         irqflags = IRQF_TRIGGER_FALLING;
453         if (glue)
454                 irqflags = glue->irq_flags;
455
456         ret = devm_request_threaded_irq(dev, client->irq, NULL, tda9950_irq,
457                                         irqflags | IRQF_SHARED | IRQF_ONESHOT,
458                                         dev_name(&client->dev), priv);
459         if (ret < 0)
460                 return ret;
461
462         priv->notify = cec_notifier_get(priv->hdmi);
463         if (!priv->notify)
464                 return -ENOMEM;
465
466         ret = cec_register_adapter(priv->adap, priv->hdmi);
467         if (ret < 0) {
468                 cec_notifier_put(priv->notify);
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         cec_register_cec_notifier(priv->adap, priv->notify);
479
480         return 0;
481 }
482
483 static int tda9950_remove(struct i2c_client *client)
484 {
485         struct tda9950_priv *priv = i2c_get_clientdata(client);
486
487         cec_unregister_adapter(priv->adap);
488         cec_notifier_put(priv->notify);
489
490         return 0;
491 }
492
493 static struct i2c_device_id tda9950_ids[] = {
494         { "tda9950", 0 },
495         { },
496 };
497 MODULE_DEVICE_TABLE(i2c, tda9950_ids);
498
499 static struct i2c_driver tda9950_driver = {
500         .probe = tda9950_probe,
501         .remove = tda9950_remove,
502         .driver = {
503                 .name = "tda9950",
504         },
505         .id_table = tda9950_ids,
506 };
507
508 module_i2c_driver(tda9950_driver);
509
510 MODULE_AUTHOR("Russell King <rmk+kernel@armlinux.org.uk>");
511 MODULE_DESCRIPTION("TDA9950/TDA998x Consumer Electronics Control Driver");
512 MODULE_LICENSE("GPL v2");