1#include <media/saa7146_vv.h> 2 3static u32 saa7146_i2c_func(struct i2c_adapter *adapter) 4{ 5//fm DEB_I2C(("'%s'.\n", adapter->name)); 6 7 return I2C_FUNC_I2C 8 | I2C_FUNC_SMBUS_QUICK 9 | I2C_FUNC_SMBUS_READ_BYTE | I2C_FUNC_SMBUS_WRITE_BYTE 10 | I2C_FUNC_SMBUS_READ_BYTE_DATA | I2C_FUNC_SMBUS_WRITE_BYTE_DATA; 11} 12 13/* this function returns the status-register of our i2c-device */ 14static inline u32 saa7146_i2c_status(struct saa7146_dev *dev) 15{ 16 u32 iicsta = saa7146_read(dev, I2C_STATUS); 17/* 18 DEB_I2C(("status: 0x%08x\n",iicsta)); 19*/ 20 return iicsta; 21} 22 23/* this function runs through the i2c-messages and prepares the data to be 24 sent through the saa7146. have a look at the specifications p. 122 ff 25 to understand this. it returns the number of u32s to send, or -1 26 in case of an error. */ 27static int saa7146_i2c_msg_prepare(const struct i2c_msg *m, int num, u32 *op) 28{ 29 int h1, h2; 30 int i, j, addr; 31 int mem = 0, op_count = 0; 32 33 /* first determine size of needed memory */ 34 for(i = 0; i < num; i++) { 35 mem += m[i].len + 1; 36 } 37 38 /* worst case: we need one u32 for three bytes to be send 39 plus one extra byte to address the device */ 40 mem = 1 + ((mem-1) / 3); 41 42 /* we assume that op points to a memory of at least SAA7146_I2C_MEM bytes 43 size. if we exceed this limit... */ 44 if ( (4*mem) > SAA7146_I2C_MEM ) { 45//fm DEB_I2C(("cannot prepare i2c-message.\n")); 46 return -ENOMEM; 47 } 48 49 /* be careful: clear out the i2c-mem first */ 50 memset(op,0,sizeof(u32)*mem); 51 52 /* loop through all messages */ 53 for(i = 0; i < num; i++) { 54 55 /* insert the address of the i2c-slave. 56 note: we get 7 bit i2c-addresses, 57 so we have to perform a translation */ 58 addr = (m[i].addr*2) + ( (0 != (m[i].flags & I2C_M_RD)) ? 1 : 0); 59 h1 = op_count/3; h2 = op_count%3; 60 op[h1] |= ( (u8)addr << ((3-h2)*8)); 61 op[h1] |= (SAA7146_I2C_START << ((3-h2)*2)); 62 op_count++; 63 64 /* loop through all bytes of message i */ 65 for(j = 0; j < m[i].len; j++) { 66 /* insert the data bytes */ 67 h1 = op_count/3; h2 = op_count%3; 68 op[h1] |= ( (u32)((u8)m[i].buf[j]) << ((3-h2)*8)); 69 op[h1] |= ( SAA7146_I2C_CONT << ((3-h2)*2)); 70 op_count++; 71 } 72 73 } 74 75 /* have a look at the last byte inserted: 76 if it was: ...CONT change it to ...STOP */ 77 h1 = (op_count-1)/3; h2 = (op_count-1)%3; 78 if ( SAA7146_I2C_CONT == (0x3 & (op[h1] >> ((3-h2)*2))) ) { 79 op[h1] &= ~(0x2 << ((3-h2)*2)); 80 op[h1] |= (SAA7146_I2C_STOP << ((3-h2)*2)); 81 } 82 83 /* return the number of u32s to send */ 84 return mem; 85} 86 87static int saa7146_i2c_msg_cleanup(const struct i2c_msg *m, int num, u32 *op) 88{ 89 int i, j; 90 int op_count = 0; 91 92 /* loop through all messages */ 93 for(i = 0; i < num; i++) { 94 95 op_count++; 96 97 /* loop throgh all bytes of message i */ 98 for(j = 0; j < m[i].len; j++) { 99 /* write back all bytes that could have been read */ 100 m[i].buf[j] = (op[op_count/3] >> ((3-(op_count%3))*8)); 101 op_count++; 102 } 103 } 104 105 return 0; 106} 107 108/* this functions resets the i2c-device and returns 0 if everything was fine, otherwise -1 */ 109static int saa7146_i2c_reset(struct saa7146_dev *dev) 110{ 111 /* get current status */ 112 u32 status = saa7146_i2c_status(dev); 113 114 /* clear registers for sure */ 115 saa7146_write(dev, I2C_STATUS, dev->i2c_bitrate); 116 saa7146_write(dev, I2C_TRANSFER, 0); 117 118 /* check if any operation is still in progress */ 119 if ( 0 != ( status & SAA7146_I2C_BUSY) ) { 120 121 /* yes, kill ongoing operation */ 122 DEB_I2C(("busy_state detected.\n")); 123 124 /* set "ABORT-OPERATION"-bit (bit 7)*/ 125 saa7146_write(dev, I2C_STATUS, (dev->i2c_bitrate | MASK_07)); 126 saa7146_write(dev, MC2, (MASK_00 | MASK_16)); 127 msleep(SAA7146_I2C_DELAY); 128 129 /* clear all error-bits pending; this is needed because p.123, note 1 */ 130 saa7146_write(dev, I2C_STATUS, dev->i2c_bitrate); 131 saa7146_write(dev, MC2, (MASK_00 | MASK_16)); 132 msleep(SAA7146_I2C_DELAY); 133 } 134 135 /* check if any error is (still) present. (this can be necessary because p.123, note 1) */ 136 status = saa7146_i2c_status(dev); 137 138 if ( dev->i2c_bitrate != status ) { 139 140 DEB_I2C(("error_state detected. status:0x%08x\n",status)); 141 142 /* Repeat the abort operation. This seems to be necessary 143 after serious protocol errors caused by e.g. the SAA7740 */ 144 saa7146_write(dev, I2C_STATUS, (dev->i2c_bitrate | MASK_07)); 145 saa7146_write(dev, MC2, (MASK_00 | MASK_16)); 146 msleep(SAA7146_I2C_DELAY); 147 148 /* clear all error-bits pending */ 149 saa7146_write(dev, I2C_STATUS, dev->i2c_bitrate); 150 saa7146_write(dev, MC2, (MASK_00 | MASK_16)); 151 msleep(SAA7146_I2C_DELAY); 152 153 /* the data sheet says it might be necessary to clear the status 154 twice after an abort */ 155 saa7146_write(dev, I2C_STATUS, dev->i2c_bitrate); 156 saa7146_write(dev, MC2, (MASK_00 | MASK_16)); 157 msleep(SAA7146_I2C_DELAY); 158 } 159 160 /* if any error is still present, a fatal error has occured ... */ 161 status = saa7146_i2c_status(dev); 162 if ( dev->i2c_bitrate != status ) { 163 DEB_I2C(("fatal error. status:0x%08x\n",status)); 164 return -1; 165 } 166 167 return 0; 168} 169 170/* this functions writes out the data-byte 'dword' to the i2c-device. 171 it returns 0 if ok, -1 if the transfer failed, -2 if the transfer 172 failed badly (e.g. address error) */ 173static int saa7146_i2c_writeout(struct saa7146_dev *dev, u32* dword, int short_delay) 174{ 175 u32 status = 0, mc2 = 0; 176 int trial = 0; 177 unsigned long timeout; 178 179 /* write out i2c-command */ 180 DEB_I2C(("before: 0x%08x (status: 0x%08x), %d\n",*dword,saa7146_read(dev, I2C_STATUS), dev->i2c_op)); 181 182 if( 0 != (SAA7146_USE_I2C_IRQ & dev->ext->flags)) { 183 184 saa7146_write(dev, I2C_STATUS, dev->i2c_bitrate); 185 saa7146_write(dev, I2C_TRANSFER, *dword); 186 187 dev->i2c_op = 1; 188 SAA7146_ISR_CLEAR(dev, MASK_16|MASK_17); 189 SAA7146_IER_ENABLE(dev, MASK_16|MASK_17); 190 saa7146_write(dev, MC2, (MASK_00 | MASK_16)); 191 192 timeout = HZ/100 + 1; /* 10ms */ 193 timeout = wait_event_interruptible_timeout(dev->i2c_wq, dev->i2c_op == 0, timeout); 194 if (timeout == -ERESTARTSYS || dev->i2c_op) { 195 SAA7146_IER_DISABLE(dev, MASK_16|MASK_17); 196 SAA7146_ISR_CLEAR(dev, MASK_16|MASK_17); 197 if (timeout == -ERESTARTSYS) 198 /* a signal arrived */ 199 return -ERESTARTSYS; 200 201 printk(KERN_WARNING "saa7146_i2c_writeout: timed out waiting for end of xfer\n"); 202 return -EIO; 203 } 204 status = saa7146_read(dev, I2C_STATUS); 205 } else { 206 saa7146_write(dev, I2C_STATUS, dev->i2c_bitrate); 207 saa7146_write(dev, I2C_TRANSFER, *dword); 208 saa7146_write(dev, MC2, (MASK_00 | MASK_16)); 209 210 /* do not poll for i2c-status before upload is complete */ 211 timeout = jiffies + HZ/100 + 1; /* 10ms */ 212 while(1) { 213 mc2 = (saa7146_read(dev, MC2) & 0x1); 214 if( 0 != mc2 ) { 215 break; 216 } 217 if (time_after(jiffies,timeout)) { 218 printk(KERN_WARNING "saa7146_i2c_writeout: timed out waiting for MC2\n"); 219 return -EIO; 220 } 221 } 222 /* wait until we get a transfer done or error */ 223 timeout = jiffies + HZ/100 + 1; /* 10ms */ 224 /* first read usually delivers bogus results... */ 225 saa7146_i2c_status(dev); 226 while(1) { 227 status = saa7146_i2c_status(dev); 228 if ((status & 0x3) != 1) 229 break; 230 if (time_after(jiffies,timeout)) { 231 /* this is normal when probing the bus 232 * (no answer from nonexisistant device...) 233 */ 234 DEB_I2C(("saa7146_i2c_writeout: timed out waiting for end of xfer\n")); 235 return -EIO; 236 } 237 if (++trial < 50 && short_delay) 238 udelay(10); 239 else 240 msleep(1); 241 } 242 } 243 244 /* give a detailed status report */ 245 if ( 0 != (status & SAA7146_I2C_ERR)) { 246 247 if( 0 != (status & SAA7146_I2C_SPERR) ) { 248 DEB_I2C(("error due to invalid start/stop condition.\n")); 249 } 250 if( 0 != (status & SAA7146_I2C_DTERR) ) { 251 DEB_I2C(("error in data transmission.\n")); 252 } 253 if( 0 != (status & SAA7146_I2C_DRERR) ) { 254 DEB_I2C(("error when receiving data.\n")); 255 } 256 if( 0 != (status & SAA7146_I2C_AL) ) { 257 DEB_I2C(("error because arbitration lost.\n")); 258 } 259 260 /* we handle address-errors here */ 261 if( 0 != (status & SAA7146_I2C_APERR) ) { 262 DEB_I2C(("error in address phase.\n")); 263 return -EREMOTEIO; 264 } 265 266 return -EIO; 267 } 268 269 /* read back data, just in case we were reading ... */ 270 *dword = saa7146_read(dev, I2C_TRANSFER); 271 272 DEB_I2C(("after: 0x%08x\n",*dword)); 273 return 0; 274} 275 276int saa7146_i2c_transfer(struct saa7146_dev *dev, const struct i2c_msg *msgs, int num, int retries) 277{ 278 int i = 0, count = 0; 279 u32* buffer = dev->d_i2c.cpu_addr; 280 int err = 0; 281 int address_err = 0; 282 int short_delay = 0; 283 284 if (mutex_lock_interruptible(&dev->i2c_lock)) 285 return -ERESTARTSYS; 286 287 for(i=0;i<num;i++) { 288 DEB_I2C(("msg:%d/%d\n",i+1,num)); 289 } 290 291 /* prepare the message(s), get number of u32s to transfer */ 292 count = saa7146_i2c_msg_prepare(msgs, num, buffer); 293 if ( 0 > count ) { 294 err = -1; 295 goto out; 296 } 297 298 if ( count > 3 || 0 != (SAA7146_I2C_SHORT_DELAY & dev->ext->flags) ) 299 short_delay = 1; 300 301 do { 302 /* reset the i2c-device if necessary */ 303 err = saa7146_i2c_reset(dev); 304 if ( 0 > err ) { 305 DEB_I2C(("could not reset i2c-device.\n")); 306 goto out; 307 } 308 309 /* write out the u32s one after another */ 310 for(i = 0; i < count; i++) { 311 err = saa7146_i2c_writeout(dev, &buffer[i], short_delay); 312 if ( 0 != err) { 313 /* this one is unsatisfying: some i2c slaves on some 314 dvb cards don't acknowledge correctly, so the saa7146 315 thinks that an address error occured. in that case, the 316 transaction should be retrying, even if an address error 317 occured. analog saa7146 based cards extensively rely on 318 i2c address probing, however, and address errors indicate that a 319 device is really *not* there. retrying in that case 320 increases the time the device needs to probe greatly, so 321 it should be avoided. because of the fact, that only 322 analog based cards use irq based i2c transactions (for dvb 323 cards, this screwes up other interrupt sources), we bail out 324 completely for analog cards after an address error and trust 325 the saa7146 address error detection. */ 326 if ( -EREMOTEIO == err ) { 327 if( 0 != (SAA7146_USE_I2C_IRQ & dev->ext->flags)) { 328 goto out; 329 } 330 address_err++; 331 } 332 DEB_I2C(("error while sending message(s). starting again.\n")); 333 break; 334 } 335 } 336 if( 0 == err ) { 337 err = num; 338 break; 339 } 340 341 /* delay a bit before retrying */ 342 msleep(10); 343 344 } while (err != num && retries--); 345 346 /* if every retry had an address error, exit right away */ 347 if (address_err == retries) { 348 goto out; 349 } 350 351 /* if any things had to be read, get the results */ 352 if ( 0 != saa7146_i2c_msg_cleanup(msgs, num, buffer)) { 353 DEB_I2C(("could not cleanup i2c-message.\n")); 354 err = -1; 355 goto out; 356 } 357 358 /* return the number of delivered messages */ 359 DEB_I2C(("transmission successful. (msg:%d).\n",err)); 360out: 361 /* another bug in revision 0: the i2c-registers get uploaded randomly by other 362 uploads, so we better clear them out before continueing */ 363 if( 0 == dev->revision ) { 364 u32 zero = 0; 365 saa7146_i2c_reset(dev); 366 if( 0 != saa7146_i2c_writeout(dev, &zero, short_delay)) { 367 INFO(("revision 0 error. this should never happen.\n")); 368 } 369 } 370 371 mutex_unlock(&dev->i2c_lock); 372 return err; 373} 374 375/* utility functions */ 376static int saa7146_i2c_xfer(struct i2c_adapter* adapter, struct i2c_msg *msg, int num) 377{ 378 struct saa7146_dev* dev = i2c_get_adapdata(adapter); 379 380 /* use helper function to transfer data */ 381 return saa7146_i2c_transfer(dev, msg, num, adapter->retries); 382} 383 384 385/*****************************************************************************/ 386/* i2c-adapter helper functions */ 387#include <linux/i2c-id.h> 388 389/* exported algorithm data */ 390static struct i2c_algorithm saa7146_algo = { 391 .master_xfer = saa7146_i2c_xfer, 392 .functionality = saa7146_i2c_func, 393}; 394 395int saa7146_i2c_adapter_prepare(struct saa7146_dev *dev, struct i2c_adapter *i2c_adapter, u32 bitrate) 396{ 397 DEB_EE(("bitrate: 0x%08x\n",bitrate)); 398 399 /* enable i2c-port pins */ 400 saa7146_write(dev, MC1, (MASK_08 | MASK_24)); 401 402 dev->i2c_bitrate = bitrate; 403 saa7146_i2c_reset(dev); 404 405 if( NULL != i2c_adapter ) { 406 BUG_ON(!i2c_adapter->class); 407 i2c_set_adapdata(i2c_adapter,dev); 408 i2c_adapter->dev.parent = &dev->pci->dev; 409 i2c_adapter->algo = &saa7146_algo; 410 i2c_adapter->algo_data = NULL; 411 i2c_adapter->id = I2C_HW_SAA7146; 412 i2c_adapter->timeout = SAA7146_I2C_TIMEOUT; 413 i2c_adapter->retries = SAA7146_I2C_RETRIES; 414 } 415 416 return 0; 417} 418