1 /* 2 * Driver for the Auvitek AU0828 USB bridge 3 * 4 * Copyright (c) 2008 Steven Toth <stoth@linuxtv.org> 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation; either version 2 of the License, or 9 * (at your option) any later version. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * 15 * GNU General Public License for more details. 16 * 17 * You should have received a copy of the GNU General Public License 18 * along with this program; if not, write to the Free Software 19 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 20 */ 21 22 #include <linux/module.h> 23 #include <linux/moduleparam.h> 24 #include <linux/init.h> 25 #include <linux/delay.h> 26 #include <linux/io.h> 27 28 #include "au0828.h" 29 #include "media/tuner.h" 30 #include <media/v4l2-common.h> 31 32 static int i2c_scan; 33 module_param(i2c_scan, int, 0444); 34 MODULE_PARM_DESC(i2c_scan, "scan i2c bus at insmod time"); 35 36 #define I2C_WAIT_DELAY 25 37 #define I2C_WAIT_RETRY 1000 38 39 static inline int i2c_slave_did_write_ack(struct i2c_adapter *i2c_adap) 40 { 41 struct au0828_dev *dev = i2c_adap->algo_data; 42 return au0828_read(dev, AU0828_I2C_STATUS_201) & 43 AU0828_I2C_STATUS_NO_WRITE_ACK ? 0 : 1; 44 } 45 46 static inline int i2c_slave_did_read_ack(struct i2c_adapter *i2c_adap) 47 { 48 struct au0828_dev *dev = i2c_adap->algo_data; 49 return au0828_read(dev, AU0828_I2C_STATUS_201) & 50 AU0828_I2C_STATUS_NO_READ_ACK ? 0 : 1; 51 } 52 53 static int i2c_wait_read_ack(struct i2c_adapter *i2c_adap) 54 { 55 int count; 56 57 for (count = 0; count < I2C_WAIT_RETRY; count++) { 58 if (!i2c_slave_did_read_ack(i2c_adap)) 59 break; 60 udelay(I2C_WAIT_DELAY); 61 } 62 63 if (I2C_WAIT_RETRY == count) 64 return 0; 65 66 return 1; 67 } 68 69 static inline int i2c_is_read_busy(struct i2c_adapter *i2c_adap) 70 { 71 struct au0828_dev *dev = i2c_adap->algo_data; 72 return au0828_read(dev, AU0828_I2C_STATUS_201) & 73 AU0828_I2C_STATUS_READ_DONE ? 0 : 1; 74 } 75 76 static int i2c_wait_read_done(struct i2c_adapter *i2c_adap) 77 { 78 int count; 79 80 for (count = 0; count < I2C_WAIT_RETRY; count++) { 81 if (!i2c_is_read_busy(i2c_adap)) 82 break; 83 udelay(I2C_WAIT_DELAY); 84 } 85 86 if (I2C_WAIT_RETRY == count) 87 return 0; 88 89 return 1; 90 } 91 92 static inline int i2c_is_write_done(struct i2c_adapter *i2c_adap) 93 { 94 struct au0828_dev *dev = i2c_adap->algo_data; 95 return au0828_read(dev, AU0828_I2C_STATUS_201) & 96 AU0828_I2C_STATUS_WRITE_DONE ? 1 : 0; 97 } 98 99 static int i2c_wait_write_done(struct i2c_adapter *i2c_adap) 100 { 101 int count; 102 103 for (count = 0; count < I2C_WAIT_RETRY; count++) { 104 if (i2c_is_write_done(i2c_adap)) 105 break; 106 udelay(I2C_WAIT_DELAY); 107 } 108 109 if (I2C_WAIT_RETRY == count) 110 return 0; 111 112 return 1; 113 } 114 115 static inline int i2c_is_busy(struct i2c_adapter *i2c_adap) 116 { 117 struct au0828_dev *dev = i2c_adap->algo_data; 118 return au0828_read(dev, AU0828_I2C_STATUS_201) & 119 AU0828_I2C_STATUS_BUSY ? 1 : 0; 120 } 121 122 static int i2c_wait_done(struct i2c_adapter *i2c_adap) 123 { 124 int count; 125 126 for (count = 0; count < I2C_WAIT_RETRY; count++) { 127 if (!i2c_is_busy(i2c_adap)) 128 break; 129 udelay(I2C_WAIT_DELAY); 130 } 131 132 if (I2C_WAIT_RETRY == count) 133 return 0; 134 135 return 1; 136 } 137 138 /* FIXME: Implement join handling correctly */ 139 static int i2c_sendbytes(struct i2c_adapter *i2c_adap, 140 const struct i2c_msg *msg, int joined_rlen) 141 { 142 int i, strobe = 0; 143 struct au0828_dev *dev = i2c_adap->algo_data; 144 u8 i2c_speed = dev->board.i2c_clk_divider; 145 146 dprintk(4, "%s()\n", __func__); 147 148 au0828_write(dev, AU0828_I2C_MULTIBYTE_MODE_2FF, 0x01); 149 150 if (((dev->board.tuner_type == TUNER_XC5000) || 151 (dev->board.tuner_type == TUNER_XC5000C)) && 152 (dev->board.tuner_addr == msg->addr)) { 153 /* 154 * Due to I2C clock stretch, we need to use a lower speed 155 * on xc5000 for commands. However, firmware transfer can 156 * speed up to 400 KHz. 157 */ 158 if (msg->len == 64) 159 i2c_speed = AU0828_I2C_CLK_250KHZ; 160 else 161 i2c_speed = AU0828_I2C_CLK_20KHZ; 162 } 163 /* Set the I2C clock */ 164 au0828_write(dev, AU0828_I2C_CLK_DIVIDER_202, i2c_speed); 165 166 /* Hardware needs 8 bit addresses */ 167 au0828_write(dev, AU0828_I2C_DEST_ADDR_203, msg->addr << 1); 168 169 dprintk(4, "SEND: %02x\n", msg->addr); 170 171 /* Deal with i2c_scan */ 172 if (msg->len == 0) { 173 /* The analog tuner detection code makes use of the SMBUS_QUICK 174 message (which involves a zero length i2c write). To avoid 175 checking the status register when we didn't strobe out any 176 actual bytes to the bus, just do a read check. This is 177 consistent with how I saw i2c device checking done in the 178 USB trace of the Windows driver */ 179 au0828_write(dev, AU0828_I2C_TRIGGER_200, 180 AU0828_I2C_TRIGGER_READ); 181 182 if (!i2c_wait_done(i2c_adap)) 183 return -EIO; 184 185 if (i2c_wait_read_ack(i2c_adap)) 186 return -EIO; 187 188 return 0; 189 } 190 191 for (i = 0; i < msg->len;) { 192 193 dprintk(4, " %02x\n", msg->buf[i]); 194 195 au0828_write(dev, AU0828_I2C_WRITE_FIFO_205, msg->buf[i]); 196 197 strobe++; 198 i++; 199 200 if ((strobe >= 4) || (i >= msg->len)) { 201 202 /* Strobe the byte into the bus */ 203 if (i < msg->len) 204 au0828_write(dev, AU0828_I2C_TRIGGER_200, 205 AU0828_I2C_TRIGGER_WRITE | 206 AU0828_I2C_TRIGGER_HOLD); 207 else 208 au0828_write(dev, AU0828_I2C_TRIGGER_200, 209 AU0828_I2C_TRIGGER_WRITE); 210 211 /* Reset strobe trigger */ 212 strobe = 0; 213 214 if (!i2c_wait_write_done(i2c_adap)) 215 return -EIO; 216 217 } 218 219 } 220 if (!i2c_wait_done(i2c_adap)) 221 return -EIO; 222 223 dprintk(4, "\n"); 224 225 return msg->len; 226 } 227 228 /* FIXME: Implement join handling correctly */ 229 static int i2c_readbytes(struct i2c_adapter *i2c_adap, 230 const struct i2c_msg *msg, int joined) 231 { 232 struct au0828_dev *dev = i2c_adap->algo_data; 233 u8 i2c_speed = dev->board.i2c_clk_divider; 234 int i; 235 236 dprintk(4, "%s()\n", __func__); 237 238 au0828_write(dev, AU0828_I2C_MULTIBYTE_MODE_2FF, 0x01); 239 240 /* 241 * Due to xc5000c clock stretch, we cannot use full speed at 242 * readings from xc5000, as otherwise they'll fail. 243 */ 244 if (((dev->board.tuner_type == TUNER_XC5000) || 245 (dev->board.tuner_type == TUNER_XC5000C)) && 246 (dev->board.tuner_addr == msg->addr)) 247 i2c_speed = AU0828_I2C_CLK_20KHZ; 248 249 /* Set the I2C clock */ 250 au0828_write(dev, AU0828_I2C_CLK_DIVIDER_202, i2c_speed); 251 252 /* Hardware needs 8 bit addresses */ 253 au0828_write(dev, AU0828_I2C_DEST_ADDR_203, msg->addr << 1); 254 255 dprintk(4, " RECV:\n"); 256 257 /* Deal with i2c_scan */ 258 if (msg->len == 0) { 259 au0828_write(dev, AU0828_I2C_TRIGGER_200, 260 AU0828_I2C_TRIGGER_READ); 261 262 if (i2c_wait_read_ack(i2c_adap)) 263 return -EIO; 264 return 0; 265 } 266 267 for (i = 0; i < msg->len;) { 268 269 i++; 270 271 if (i < msg->len) 272 au0828_write(dev, AU0828_I2C_TRIGGER_200, 273 AU0828_I2C_TRIGGER_READ | 274 AU0828_I2C_TRIGGER_HOLD); 275 else 276 au0828_write(dev, AU0828_I2C_TRIGGER_200, 277 AU0828_I2C_TRIGGER_READ); 278 279 if (!i2c_wait_read_done(i2c_adap)) 280 return -EIO; 281 282 msg->buf[i-1] = au0828_read(dev, AU0828_I2C_READ_FIFO_209) & 283 0xff; 284 285 dprintk(4, " %02x\n", msg->buf[i-1]); 286 } 287 if (!i2c_wait_done(i2c_adap)) 288 return -EIO; 289 290 dprintk(4, "\n"); 291 292 return msg->len; 293 } 294 295 static int i2c_xfer(struct i2c_adapter *i2c_adap, 296 struct i2c_msg *msgs, int num) 297 { 298 int i, retval = 0; 299 300 dprintk(4, "%s(num = %d)\n", __func__, num); 301 302 for (i = 0; i < num; i++) { 303 dprintk(4, "%s(num = %d) addr = 0x%02x len = 0x%x\n", 304 __func__, num, msgs[i].addr, msgs[i].len); 305 if (msgs[i].flags & I2C_M_RD) { 306 /* read */ 307 retval = i2c_readbytes(i2c_adap, &msgs[i], 0); 308 } else if (i + 1 < num && (msgs[i + 1].flags & I2C_M_RD) && 309 msgs[i].addr == msgs[i + 1].addr) { 310 /* write then read from same address */ 311 retval = i2c_sendbytes(i2c_adap, &msgs[i], 312 msgs[i + 1].len); 313 if (retval < 0) 314 goto err; 315 i++; 316 retval = i2c_readbytes(i2c_adap, &msgs[i], 1); 317 } else { 318 /* write */ 319 retval = i2c_sendbytes(i2c_adap, &msgs[i], 0); 320 } 321 if (retval < 0) 322 goto err; 323 } 324 return num; 325 326 err: 327 return retval; 328 } 329 330 static u32 au0828_functionality(struct i2c_adapter *adap) 331 { 332 return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_I2C; 333 } 334 335 static struct i2c_algorithm au0828_i2c_algo_template = { 336 .master_xfer = i2c_xfer, 337 .functionality = au0828_functionality, 338 }; 339 340 /* ----------------------------------------------------------------------- */ 341 342 static struct i2c_adapter au0828_i2c_adap_template = { 343 .name = DRIVER_NAME, 344 .owner = THIS_MODULE, 345 .algo = &au0828_i2c_algo_template, 346 }; 347 348 static struct i2c_client au0828_i2c_client_template = { 349 .name = "au0828 internal", 350 }; 351 352 static char *i2c_devs[128] = { 353 [0x8e >> 1] = "au8522", 354 [0xa0 >> 1] = "eeprom", 355 [0xc2 >> 1] = "tuner/xc5000", 356 }; 357 358 static void do_i2c_scan(char *name, struct i2c_client *c) 359 { 360 unsigned char buf; 361 int i, rc; 362 363 for (i = 0; i < 128; i++) { 364 c->addr = i; 365 rc = i2c_master_recv(c, &buf, 0); 366 if (rc < 0) 367 continue; 368 printk(KERN_INFO "%s: i2c scan: found device @ 0x%x [%s]\n", 369 name, i << 1, i2c_devs[i] ? i2c_devs[i] : "???"); 370 } 371 } 372 373 /* init + register i2c adapter */ 374 int au0828_i2c_register(struct au0828_dev *dev) 375 { 376 dprintk(1, "%s()\n", __func__); 377 378 dev->i2c_adap = au0828_i2c_adap_template; 379 dev->i2c_algo = au0828_i2c_algo_template; 380 dev->i2c_client = au0828_i2c_client_template; 381 382 dev->i2c_adap.dev.parent = &dev->usbdev->dev; 383 384 strlcpy(dev->i2c_adap.name, DRIVER_NAME, 385 sizeof(dev->i2c_adap.name)); 386 387 dev->i2c_adap.algo = &dev->i2c_algo; 388 dev->i2c_adap.algo_data = dev; 389 #ifdef CONFIG_VIDEO_AU0828_V4L2 390 i2c_set_adapdata(&dev->i2c_adap, &dev->v4l2_dev); 391 #else 392 i2c_set_adapdata(&dev->i2c_adap, dev); 393 #endif 394 i2c_add_adapter(&dev->i2c_adap); 395 396 dev->i2c_client.adapter = &dev->i2c_adap; 397 398 if (0 == dev->i2c_rc) { 399 printk(KERN_INFO "%s: i2c bus registered\n", DRIVER_NAME); 400 if (i2c_scan) 401 do_i2c_scan(DRIVER_NAME, &dev->i2c_client); 402 } else 403 printk(KERN_INFO "%s: i2c bus register FAILED\n", DRIVER_NAME); 404 405 return dev->i2c_rc; 406 } 407 408 int au0828_i2c_unregister(struct au0828_dev *dev) 409 { 410 i2c_del_adapter(&dev->i2c_adap); 411 return 0; 412 } 413 414