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