/drivers/media/video/au0828/au0828-i2c.c
C | 390 lines | 263 code | 86 blank | 41 comment | 47 complexity | 2f7b794c2fd0d1e26cdb3e5cd25f07fe MD5 | raw file
Possible License(s): GPL-2.0, LGPL-2.0, AGPL-1.0
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 30#include <media/v4l2-common.h> 31 32static int i2c_scan; 33module_param(i2c_scan, int, 0444); 34MODULE_PARM_DESC(i2c_scan, "scan i2c bus at insmod time"); 35 36#define I2C_WAIT_DELAY 512 37#define I2C_WAIT_RETRY 64 38 39static 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 46static 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 53static 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 69static 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 76static 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 92static 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 99static 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 115static 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 122static 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 */ 139static 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; 144 145 dprintk(4, "%s()\n", __func__); 146 147 au0828_write(dev, AU0828_I2C_MULTIBYTE_MODE_2FF, 0x01); 148 149 /* Set the I2C clock */ 150 au0828_write(dev, AU0828_I2C_CLK_DIVIDER_202, 151 dev->board.i2c_clk_divider); 152 153 /* Hardware needs 8 bit addresses */ 154 au0828_write(dev, AU0828_I2C_DEST_ADDR_203, msg->addr << 1); 155 156 dprintk(4, "SEND: %02x\n", msg->addr); 157 158 /* Deal with i2c_scan */ 159 if (msg->len == 0) { 160 /* The analog tuner detection code makes use of the SMBUS_QUICK 161 message (which involves a zero length i2c write). To avoid 162 checking the status register when we didn't strobe out any 163 actual bytes to the bus, just do a read check. This is 164 consistent with how I saw i2c device checking done in the 165 USB trace of the Windows driver */ 166 au0828_write(dev, AU0828_I2C_TRIGGER_200, 167 AU0828_I2C_TRIGGER_READ); 168 169 if (!i2c_wait_done(i2c_adap)) 170 return -EIO; 171 172 if (i2c_wait_read_ack(i2c_adap)) 173 return -EIO; 174 175 return 0; 176 } 177 178 for (i = 0; i < msg->len;) { 179 180 dprintk(4, " %02x\n", msg->buf[i]); 181 182 au0828_write(dev, AU0828_I2C_WRITE_FIFO_205, msg->buf[i]); 183 184 strobe++; 185 i++; 186 187 if ((strobe >= 4) || (i >= msg->len)) { 188 189 /* Strobe the byte into the bus */ 190 if (i < msg->len) 191 au0828_write(dev, AU0828_I2C_TRIGGER_200, 192 AU0828_I2C_TRIGGER_WRITE | 193 AU0828_I2C_TRIGGER_HOLD); 194 else 195 au0828_write(dev, AU0828_I2C_TRIGGER_200, 196 AU0828_I2C_TRIGGER_WRITE); 197 198 /* Reset strobe trigger */ 199 strobe = 0; 200 201 if (!i2c_wait_write_done(i2c_adap)) 202 return -EIO; 203 204 } 205 206 } 207 if (!i2c_wait_done(i2c_adap)) 208 return -EIO; 209 210 dprintk(4, "\n"); 211 212 return msg->len; 213} 214 215/* FIXME: Implement join handling correctly */ 216static int i2c_readbytes(struct i2c_adapter *i2c_adap, 217 const struct i2c_msg *msg, int joined) 218{ 219 struct au0828_dev *dev = i2c_adap->algo_data; 220 int i; 221 222 dprintk(4, "%s()\n", __func__); 223 224 au0828_write(dev, AU0828_I2C_MULTIBYTE_MODE_2FF, 0x01); 225 226 /* Set the I2C clock */ 227 au0828_write(dev, AU0828_I2C_CLK_DIVIDER_202, 228 dev->board.i2c_clk_divider); 229 230 /* Hardware needs 8 bit addresses */ 231 au0828_write(dev, AU0828_I2C_DEST_ADDR_203, msg->addr << 1); 232 233 dprintk(4, " RECV:\n"); 234 235 /* Deal with i2c_scan */ 236 if (msg->len == 0) { 237 au0828_write(dev, AU0828_I2C_TRIGGER_200, 238 AU0828_I2C_TRIGGER_READ); 239 240 if (i2c_wait_read_ack(i2c_adap)) 241 return -EIO; 242 return 0; 243 } 244 245 for (i = 0; i < msg->len;) { 246 247 i++; 248 249 if (i < msg->len) 250 au0828_write(dev, AU0828_I2C_TRIGGER_200, 251 AU0828_I2C_TRIGGER_READ | 252 AU0828_I2C_TRIGGER_HOLD); 253 else 254 au0828_write(dev, AU0828_I2C_TRIGGER_200, 255 AU0828_I2C_TRIGGER_READ); 256 257 if (!i2c_wait_read_done(i2c_adap)) 258 return -EIO; 259 260 msg->buf[i-1] = au0828_read(dev, AU0828_I2C_READ_FIFO_209) & 261 0xff; 262 263 dprintk(4, " %02x\n", msg->buf[i-1]); 264 } 265 if (!i2c_wait_done(i2c_adap)) 266 return -EIO; 267 268 dprintk(4, "\n"); 269 270 return msg->len; 271} 272 273static int i2c_xfer(struct i2c_adapter *i2c_adap, 274 struct i2c_msg *msgs, int num) 275{ 276 int i, retval = 0; 277 278 dprintk(4, "%s(num = %d)\n", __func__, num); 279 280 for (i = 0; i < num; i++) { 281 dprintk(4, "%s(num = %d) addr = 0x%02x len = 0x%x\n", 282 __func__, num, msgs[i].addr, msgs[i].len); 283 if (msgs[i].flags & I2C_M_RD) { 284 /* read */ 285 retval = i2c_readbytes(i2c_adap, &msgs[i], 0); 286 } else if (i + 1 < num && (msgs[i + 1].flags & I2C_M_RD) && 287 msgs[i].addr == msgs[i + 1].addr) { 288 /* write then read from same address */ 289 retval = i2c_sendbytes(i2c_adap, &msgs[i], 290 msgs[i + 1].len); 291 if (retval < 0) 292 goto err; 293 i++; 294 retval = i2c_readbytes(i2c_adap, &msgs[i], 1); 295 } else { 296 /* write */ 297 retval = i2c_sendbytes(i2c_adap, &msgs[i], 0); 298 } 299 if (retval < 0) 300 goto err; 301 } 302 return num; 303 304err: 305 return retval; 306} 307 308static u32 au0828_functionality(struct i2c_adapter *adap) 309{ 310 return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_I2C; 311} 312 313static struct i2c_algorithm au0828_i2c_algo_template = { 314 .master_xfer = i2c_xfer, 315 .functionality = au0828_functionality, 316}; 317 318/* ----------------------------------------------------------------------- */ 319 320static struct i2c_adapter au0828_i2c_adap_template = { 321 .name = DRIVER_NAME, 322 .owner = THIS_MODULE, 323 .algo = &au0828_i2c_algo_template, 324}; 325 326static struct i2c_client au0828_i2c_client_template = { 327 .name = "au0828 internal", 328}; 329 330static char *i2c_devs[128] = { 331 [0x8e >> 1] = "au8522", 332 [0xa0 >> 1] = "eeprom", 333 [0xc2 >> 1] = "tuner/xc5000", 334}; 335 336static void do_i2c_scan(char *name, struct i2c_client *c) 337{ 338 unsigned char buf; 339 int i, rc; 340 341 for (i = 0; i < 128; i++) { 342 c->addr = i; 343 rc = i2c_master_recv(c, &buf, 0); 344 if (rc < 0) 345 continue; 346 printk(KERN_INFO "%s: i2c scan: found device @ 0x%x [%s]\n", 347 name, i << 1, i2c_devs[i] ? i2c_devs[i] : "???"); 348 } 349} 350 351/* init + register i2c algo-bit adapter */ 352int au0828_i2c_register(struct au0828_dev *dev) 353{ 354 dprintk(1, "%s()\n", __func__); 355 356 memcpy(&dev->i2c_adap, &au0828_i2c_adap_template, 357 sizeof(dev->i2c_adap)); 358 memcpy(&dev->i2c_algo, &au0828_i2c_algo_template, 359 sizeof(dev->i2c_algo)); 360 memcpy(&dev->i2c_client, &au0828_i2c_client_template, 361 sizeof(dev->i2c_client)); 362 363 dev->i2c_adap.dev.parent = &dev->usbdev->dev; 364 365 strlcpy(dev->i2c_adap.name, DRIVER_NAME, 366 sizeof(dev->i2c_adap.name)); 367 368 dev->i2c_adap.algo = &dev->i2c_algo; 369 dev->i2c_adap.algo_data = dev; 370 i2c_set_adapdata(&dev->i2c_adap, &dev->v4l2_dev); 371 i2c_add_adapter(&dev->i2c_adap); 372 373 dev->i2c_client.adapter = &dev->i2c_adap; 374 375 if (0 == dev->i2c_rc) { 376 printk(KERN_INFO "%s: i2c bus registered\n", DRIVER_NAME); 377 if (i2c_scan) 378 do_i2c_scan(DRIVER_NAME, &dev->i2c_client); 379 } else 380 printk(KERN_INFO "%s: i2c bus register FAILED\n", DRIVER_NAME); 381 382 return dev->i2c_rc; 383} 384 385int au0828_i2c_unregister(struct au0828_dev *dev) 386{ 387 i2c_del_adapter(&dev->i2c_adap); 388 return 0; 389} 390