1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 *
4 * device driver for philips saa7134 based TV cards
5 * i2c interface support
6 *
7 * (c) 2001,02 Gerd Knorr <kraxel@bytesex.org> [SuSE Labs]
8 */
9
10 #include "saa7134.h"
11 #include "saa7134-reg.h"
12
13 #include <linux/init.h>
14 #include <linux/list.h>
15 #include <linux/module.h>
16 #include <linux/kernel.h>
17 #include <linux/delay.h>
18
19 #include <media/v4l2-common.h>
20
21 /* ----------------------------------------------------------- */
22
23 static unsigned int i2c_debug;
24 module_param(i2c_debug, int, 0644);
25 MODULE_PARM_DESC(i2c_debug,"enable debug messages [i2c]");
26
27 static unsigned int i2c_scan;
28 module_param(i2c_scan, int, 0444);
29 MODULE_PARM_DESC(i2c_scan,"scan i2c bus at insmod time");
30
31 #define i2c_dbg(level, fmt, arg...) do { \
32 if (i2c_debug == level) \
33 printk(KERN_DEBUG pr_fmt("i2c: " fmt), ## arg); \
34 } while (0)
35
36 #define i2c_cont(level, fmt, arg...) do { \
37 if (i2c_debug == level) \
38 pr_cont(fmt, ## arg); \
39 } while (0)
40
41 #define I2C_WAIT_DELAY 32
42 #define I2C_WAIT_RETRY 16
43
44 /* ----------------------------------------------------------- */
45
46 static char *str_i2c_status[] = {
47 "IDLE", "DONE_STOP", "BUSY", "TO_SCL", "TO_ARB", "DONE_WRITE",
48 "DONE_READ", "DONE_WRITE_TO", "DONE_READ_TO", "NO_DEVICE",
49 "NO_ACKN", "BUS_ERR", "ARB_LOST", "SEQ_ERR", "ST_ERR", "SW_ERR"
50 };
51
52 enum i2c_status {
53 IDLE = 0, // no I2C command pending
54 DONE_STOP = 1, // I2C command done and STOP executed
55 BUSY = 2, // executing I2C command
56 TO_SCL = 3, // executing I2C command, time out on clock stretching
57 TO_ARB = 4, // time out on arbitration trial, still trying
58 DONE_WRITE = 5, // I2C command done and awaiting next write command
59 DONE_READ = 6, // I2C command done and awaiting next read command
60 DONE_WRITE_TO = 7, // see 5, and time out on status echo
61 DONE_READ_TO = 8, // see 6, and time out on status echo
62 NO_DEVICE = 9, // no acknowledge on device slave address
63 NO_ACKN = 10, // no acknowledge after data byte transfer
64 BUS_ERR = 11, // bus error
65 ARB_LOST = 12, // arbitration lost during transfer
66 SEQ_ERR = 13, // erroneous programming sequence
67 ST_ERR = 14, // wrong status echoing
68 SW_ERR = 15 // software error
69 };
70
71 static char *str_i2c_attr[] = {
72 "NOP", "STOP", "CONTINUE", "START"
73 };
74
75 enum i2c_attr {
76 NOP = 0, // no operation on I2C bus
77 STOP = 1, // stop condition, no associated byte transfer
78 CONTINUE = 2, // continue with byte transfer
79 START = 3 // start condition with byte transfer
80 };
81
i2c_get_status(struct saa7134_dev * dev)82 static inline enum i2c_status i2c_get_status(struct saa7134_dev *dev)
83 {
84 enum i2c_status status;
85
86 status = saa_readb(SAA7134_I2C_ATTR_STATUS) & 0x0f;
87 i2c_dbg(2, "i2c stat <= %s\n", str_i2c_status[status]);
88 return status;
89 }
90
i2c_set_status(struct saa7134_dev * dev,enum i2c_status status)91 static inline void i2c_set_status(struct saa7134_dev *dev,
92 enum i2c_status status)
93 {
94 i2c_dbg(2, "i2c stat => %s\n", str_i2c_status[status]);
95 saa_andorb(SAA7134_I2C_ATTR_STATUS,0x0f,status);
96 }
97
i2c_set_attr(struct saa7134_dev * dev,enum i2c_attr attr)98 static inline void i2c_set_attr(struct saa7134_dev *dev, enum i2c_attr attr)
99 {
100 i2c_dbg(2, "i2c attr => %s\n", str_i2c_attr[attr]);
101 saa_andorb(SAA7134_I2C_ATTR_STATUS,0xc0,attr << 6);
102 }
103
i2c_is_error(enum i2c_status status)104 static inline int i2c_is_error(enum i2c_status status)
105 {
106 switch (status) {
107 case NO_DEVICE:
108 case NO_ACKN:
109 case BUS_ERR:
110 case ARB_LOST:
111 case SEQ_ERR:
112 case ST_ERR:
113 return true;
114 default:
115 return false;
116 }
117 }
118
i2c_is_idle(enum i2c_status status)119 static inline int i2c_is_idle(enum i2c_status status)
120 {
121 switch (status) {
122 case IDLE:
123 case DONE_STOP:
124 return true;
125 default:
126 return false;
127 }
128 }
129
i2c_is_busy(enum i2c_status status)130 static inline int i2c_is_busy(enum i2c_status status)
131 {
132 switch (status) {
133 case BUSY:
134 case TO_SCL:
135 case TO_ARB:
136 return true;
137 default:
138 return false;
139 }
140 }
141
i2c_is_busy_wait(struct saa7134_dev * dev)142 static int i2c_is_busy_wait(struct saa7134_dev *dev)
143 {
144 enum i2c_status status;
145 int count;
146
147 for (count = 0; count < I2C_WAIT_RETRY; count++) {
148 status = i2c_get_status(dev);
149 if (!i2c_is_busy(status))
150 break;
151 saa_wait(I2C_WAIT_DELAY);
152 }
153 if (I2C_WAIT_RETRY == count)
154 return false;
155 return true;
156 }
157
i2c_reset(struct saa7134_dev * dev)158 static int i2c_reset(struct saa7134_dev *dev)
159 {
160 enum i2c_status status;
161 int count;
162
163 i2c_dbg(2, "i2c reset\n");
164 status = i2c_get_status(dev);
165 if (!i2c_is_error(status))
166 return true;
167 i2c_set_status(dev,status);
168
169 for (count = 0; count < I2C_WAIT_RETRY; count++) {
170 status = i2c_get_status(dev);
171 if (!i2c_is_error(status))
172 break;
173 udelay(I2C_WAIT_DELAY);
174 }
175 if (I2C_WAIT_RETRY == count)
176 return false;
177
178 if (!i2c_is_idle(status))
179 return false;
180
181 i2c_set_attr(dev,NOP);
182 return true;
183 }
184
i2c_send_byte(struct saa7134_dev * dev,enum i2c_attr attr,unsigned char data)185 static inline int i2c_send_byte(struct saa7134_dev *dev,
186 enum i2c_attr attr,
187 unsigned char data)
188 {
189 enum i2c_status status;
190 __u32 dword;
191
192 /* have to write both attr + data in one 32bit word */
193 dword = saa_readl(SAA7134_I2C_ATTR_STATUS >> 2);
194 dword &= 0x0f;
195 dword |= (attr << 6);
196 dword |= ((__u32)data << 8);
197 dword |= 0x00 << 16; /* 100 kHz */
198 // dword |= 0x40 << 16; /* 400 kHz */
199 dword |= 0xf0 << 24;
200 saa_writel(SAA7134_I2C_ATTR_STATUS >> 2, dword);
201 i2c_dbg(2, "i2c data => 0x%x\n", data);
202
203 if (!i2c_is_busy_wait(dev))
204 return -EIO;
205 status = i2c_get_status(dev);
206 if (i2c_is_error(status))
207 return -EIO;
208 return 0;
209 }
210
i2c_recv_byte(struct saa7134_dev * dev)211 static inline int i2c_recv_byte(struct saa7134_dev *dev)
212 {
213 enum i2c_status status;
214 unsigned char data;
215
216 i2c_set_attr(dev,CONTINUE);
217 if (!i2c_is_busy_wait(dev))
218 return -EIO;
219 status = i2c_get_status(dev);
220 if (i2c_is_error(status))
221 return -EIO;
222 data = saa_readb(SAA7134_I2C_DATA);
223 i2c_dbg(2, "i2c data <= 0x%x\n", data);
224 return data;
225 }
226
saa7134_i2c_xfer(struct i2c_adapter * i2c_adap,struct i2c_msg * msgs,int num)227 static int saa7134_i2c_xfer(struct i2c_adapter *i2c_adap,
228 struct i2c_msg *msgs, int num)
229 {
230 struct saa7134_dev *dev = i2c_adap->algo_data;
231 enum i2c_status status;
232 unsigned char data;
233 int addr,rc,i,byte;
234
235 status = i2c_get_status(dev);
236 if (!i2c_is_idle(status))
237 if (!i2c_reset(dev))
238 return -EIO;
239
240 i2c_dbg(2, "start xfer\n");
241 i2c_dbg(1, "i2c xfer:");
242 for (i = 0; i < num; i++) {
243 if (!(msgs[i].flags & I2C_M_NOSTART) || 0 == i) {
244 /* send address */
245 i2c_dbg(2, "send address\n");
246 addr = msgs[i].addr << 1;
247 if (msgs[i].flags & I2C_M_RD)
248 addr |= 1;
249 if (i > 0 && msgs[i].flags &
250 I2C_M_RD && msgs[i].addr != 0x40 &&
251 msgs[i].addr != 0x41 &&
252 msgs[i].addr != 0x19) {
253 /* workaround for a saa7134 i2c bug
254 * needed to talk to the mt352 demux
255 * thanks to pinnacle for the hint */
256 int quirk = 0xfe;
257 i2c_cont(1, " [%02x quirk]", quirk);
258 i2c_send_byte(dev,START,quirk);
259 i2c_recv_byte(dev);
260 }
261 i2c_cont(1, " < %02x", addr);
262 rc = i2c_send_byte(dev,START,addr);
263 if (rc < 0)
264 goto err;
265 }
266 if (msgs[i].flags & I2C_M_RD) {
267 /* read bytes */
268 i2c_dbg(2, "read bytes\n");
269 for (byte = 0; byte < msgs[i].len; byte++) {
270 i2c_cont(1, " =");
271 rc = i2c_recv_byte(dev);
272 if (rc < 0)
273 goto err;
274 i2c_cont(1, "%02x", rc);
275 msgs[i].buf[byte] = rc;
276 }
277 /* discard mysterious extra byte when reading
278 from Samsung S5H1411. i2c bus gets error
279 if we do not. */
280 if (0x19 == msgs[i].addr) {
281 i2c_cont(1, " ?");
282 rc = i2c_recv_byte(dev);
283 if (rc < 0)
284 goto err;
285 i2c_cont(1, "%02x", rc);
286 }
287 } else {
288 /* write bytes */
289 i2c_dbg(2, "write bytes\n");
290 for (byte = 0; byte < msgs[i].len; byte++) {
291 data = msgs[i].buf[byte];
292 i2c_cont(1, " %02x", data);
293 rc = i2c_send_byte(dev,CONTINUE,data);
294 if (rc < 0)
295 goto err;
296 }
297 }
298 }
299 i2c_dbg(2, "xfer done\n");
300 i2c_cont(1, " >");
301 i2c_set_attr(dev,STOP);
302 rc = -EIO;
303 if (!i2c_is_busy_wait(dev))
304 goto err;
305 status = i2c_get_status(dev);
306 if (i2c_is_error(status))
307 goto err;
308 /* ensure that the bus is idle for at least one bit slot */
309 msleep(1);
310
311 i2c_cont(1, "\n");
312 return num;
313 err:
314 if (1 == i2c_debug) {
315 status = i2c_get_status(dev);
316 i2c_cont(1, " ERROR: %s\n", str_i2c_status[status]);
317 }
318 return rc;
319 }
320
321 /* ----------------------------------------------------------- */
322
functionality(struct i2c_adapter * adap)323 static u32 functionality(struct i2c_adapter *adap)
324 {
325 return I2C_FUNC_SMBUS_EMUL;
326 }
327
328 static const struct i2c_algorithm saa7134_algo = {
329 .master_xfer = saa7134_i2c_xfer,
330 .functionality = functionality,
331 };
332
333 static const struct i2c_adapter saa7134_adap_template = {
334 .owner = THIS_MODULE,
335 .name = "saa7134",
336 .algo = &saa7134_algo,
337 };
338
339 static const struct i2c_client saa7134_client_template = {
340 .name = "saa7134 internal",
341 };
342
343 /* ----------------------------------------------------------- */
344
345 /*
346 * On Medion 7134 reading the SAA7134 chip config EEPROM needs DVB-T
347 * demod i2c gate closed due to an address clash between this EEPROM
348 * and the demod one.
349 */
saa7134_i2c_eeprom_md7134_gate(struct saa7134_dev * dev)350 static void saa7134_i2c_eeprom_md7134_gate(struct saa7134_dev *dev)
351 {
352 u8 subaddr = 0x7, dmdregval;
353 u8 data[2];
354 int ret;
355 struct i2c_msg i2cgatemsg_r[] = { {.addr = 0x08, .flags = 0,
356 .buf = &subaddr, .len = 1},
357 {.addr = 0x08,
358 .flags = I2C_M_RD,
359 .buf = &dmdregval, .len = 1}
360 };
361 struct i2c_msg i2cgatemsg_w[] = { {.addr = 0x08, .flags = 0,
362 .buf = data, .len = 2} };
363
364 ret = i2c_transfer(&dev->i2c_adap, i2cgatemsg_r, 2);
365 if ((ret == 2) && (dmdregval & 0x2)) {
366 pr_debug("%s: DVB-T demod i2c gate was left open\n",
367 dev->name);
368
369 data[0] = subaddr;
370 data[1] = (dmdregval & ~0x2);
371 if (i2c_transfer(&dev->i2c_adap, i2cgatemsg_w, 1) != 1)
372 pr_err("%s: EEPROM i2c gate close failure\n",
373 dev->name);
374 }
375 }
376
377 static int
saa7134_i2c_eeprom(struct saa7134_dev * dev,unsigned char * eedata,int len)378 saa7134_i2c_eeprom(struct saa7134_dev *dev, unsigned char *eedata, int len)
379 {
380 unsigned char buf;
381 int i,err;
382
383 if (dev->board == SAA7134_BOARD_MD7134)
384 saa7134_i2c_eeprom_md7134_gate(dev);
385
386 dev->i2c_client.addr = 0xa0 >> 1;
387 buf = 0;
388 if (1 != (err = i2c_master_send(&dev->i2c_client,&buf,1))) {
389 pr_info("%s: Huh, no eeprom present (err=%d)?\n",
390 dev->name,err);
391 return -1;
392 }
393 if (len != (err = i2c_master_recv(&dev->i2c_client,eedata,len))) {
394 pr_warn("%s: i2c eeprom read error (err=%d)\n",
395 dev->name,err);
396 return -1;
397 }
398
399 for (i = 0; i < len; i += 16) {
400 int size = (len - i) > 16 ? 16 : len - i;
401
402 pr_info("i2c eeprom %02x: %*ph\n", i, size, &eedata[i]);
403 }
404
405 return 0;
406 }
407
408 static char *i2c_devs[128] = {
409 [ 0x20 ] = "mpeg encoder (saa6752hs)",
410 [ 0xa0 >> 1 ] = "eeprom",
411 [ 0xc0 >> 1 ] = "tuner (analog)",
412 [ 0x86 >> 1 ] = "tda9887",
413 [ 0x5a >> 1 ] = "remote control",
414 };
415
do_i2c_scan(struct i2c_client * c)416 static void do_i2c_scan(struct i2c_client *c)
417 {
418 unsigned char buf;
419 int i,rc;
420
421 for (i = 0; i < ARRAY_SIZE(i2c_devs); i++) {
422 c->addr = i;
423 rc = i2c_master_recv(c,&buf,0);
424 if (rc < 0)
425 continue;
426 pr_info("i2c scan: found device @ 0x%x [%s]\n",
427 i << 1, i2c_devs[i] ? i2c_devs[i] : "???");
428 }
429 }
430
saa7134_i2c_register(struct saa7134_dev * dev)431 int saa7134_i2c_register(struct saa7134_dev *dev)
432 {
433 dev->i2c_adap = saa7134_adap_template;
434 dev->i2c_adap.dev.parent = &dev->pci->dev;
435 strscpy(dev->i2c_adap.name, dev->name, sizeof(dev->i2c_adap.name));
436 dev->i2c_adap.algo_data = dev;
437 i2c_set_adapdata(&dev->i2c_adap, &dev->v4l2_dev);
438 i2c_add_adapter(&dev->i2c_adap);
439
440 dev->i2c_client = saa7134_client_template;
441 dev->i2c_client.adapter = &dev->i2c_adap;
442
443 saa7134_i2c_eeprom(dev,dev->eedata,sizeof(dev->eedata));
444 if (i2c_scan)
445 do_i2c_scan(&dev->i2c_client);
446
447 /* Instantiate the IR receiver device, if present */
448 saa7134_probe_i2c_ir(dev);
449 return 0;
450 }
451
saa7134_i2c_unregister(struct saa7134_dev * dev)452 int saa7134_i2c_unregister(struct saa7134_dev *dev)
453 {
454 i2c_del_adapter(&dev->i2c_adap);
455 return 0;
456 }
457