1 /* 2 * Driver for the Conexant CX25821 PCIe bridge 3 * 4 * Copyright (C) 2009 Conexant Systems Inc. 5 * Authors <shu.lin@conexant.com>, <hiep.huynh@conexant.com> 6 * Based on Steven Toth <stoth@linuxtv.org> cx23885 driver 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License as published by 10 * the Free Software Foundation; either version 2 of the License, or 11 * (at your option) any later version. 12 * 13 * This program is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 * 17 * GNU General Public License for more details. 18 * 19 * You should have received a copy of the GNU General Public License 20 * along with this program; if not, write to the Free Software 21 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 22 */ 23 24 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 25 26 #include <linux/module.h> 27 #include <linux/i2c.h> 28 #include "cx25821.h" 29 30 static unsigned int i2c_debug; 31 module_param(i2c_debug, int, 0644); 32 MODULE_PARM_DESC(i2c_debug, "enable debug messages [i2c]"); 33 34 static unsigned int i2c_scan; 35 module_param(i2c_scan, int, 0444); 36 MODULE_PARM_DESC(i2c_scan, "scan i2c bus at insmod time"); 37 38 #define dprintk(level, fmt, arg...) \ 39 do { \ 40 if (i2c_debug >= level) \ 41 printk(KERN_DEBUG "%s/0: " fmt, dev->name, ##arg); \ 42 } while (0) 43 44 #define I2C_WAIT_DELAY 32 45 #define I2C_WAIT_RETRY 64 46 47 #define I2C_EXTEND (1 << 3) 48 #define I2C_NOSTOP (1 << 4) 49 50 static inline int i2c_slave_did_ack(struct i2c_adapter *i2c_adap) 51 { 52 struct cx25821_i2c *bus = i2c_adap->algo_data; 53 struct cx25821_dev *dev = bus->dev; 54 return cx_read(bus->reg_stat) & 0x01; 55 } 56 57 static inline int i2c_is_busy(struct i2c_adapter *i2c_adap) 58 { 59 struct cx25821_i2c *bus = i2c_adap->algo_data; 60 struct cx25821_dev *dev = bus->dev; 61 return cx_read(bus->reg_stat) & 0x02 ? 1 : 0; 62 } 63 64 static int i2c_wait_done(struct i2c_adapter *i2c_adap) 65 { 66 int count; 67 68 for (count = 0; count < I2C_WAIT_RETRY; count++) { 69 if (!i2c_is_busy(i2c_adap)) 70 break; 71 udelay(I2C_WAIT_DELAY); 72 } 73 74 if (I2C_WAIT_RETRY == count) 75 return 0; 76 77 return 1; 78 } 79 80 static int i2c_sendbytes(struct i2c_adapter *i2c_adap, 81 const struct i2c_msg *msg, int joined_rlen) 82 { 83 struct cx25821_i2c *bus = i2c_adap->algo_data; 84 struct cx25821_dev *dev = bus->dev; 85 u32 wdata, addr, ctrl; 86 int retval, cnt; 87 88 if (joined_rlen) 89 dprintk(1, "%s(msg->wlen=%d, nextmsg->rlen=%d)\n", __func__, 90 msg->len, joined_rlen); 91 else 92 dprintk(1, "%s(msg->len=%d)\n", __func__, msg->len); 93 94 /* Deal with i2c probe functions with zero payload */ 95 if (msg->len == 0) { 96 cx_write(bus->reg_addr, msg->addr << 25); 97 cx_write(bus->reg_ctrl, bus->i2c_period | (1 << 2)); 98 99 if (!i2c_wait_done(i2c_adap)) 100 return -EIO; 101 102 if (!i2c_slave_did_ack(i2c_adap)) 103 return -EIO; 104 105 dprintk(1, "%s(): returns 0\n", __func__); 106 return 0; 107 } 108 109 /* dev, reg + first byte */ 110 addr = (msg->addr << 25) | msg->buf[0]; 111 wdata = msg->buf[0]; 112 113 ctrl = bus->i2c_period | (1 << 12) | (1 << 2); 114 115 if (msg->len > 1) 116 ctrl |= I2C_NOSTOP | I2C_EXTEND; 117 else if (joined_rlen) 118 ctrl |= I2C_NOSTOP; 119 120 cx_write(bus->reg_addr, addr); 121 cx_write(bus->reg_wdata, wdata); 122 cx_write(bus->reg_ctrl, ctrl); 123 124 retval = i2c_wait_done(i2c_adap); 125 if (retval < 0) 126 goto err; 127 128 if (retval == 0) 129 goto eio; 130 131 if (i2c_debug) { 132 if (!(ctrl & I2C_NOSTOP)) 133 printk(" >\n"); 134 } 135 136 for (cnt = 1; cnt < msg->len; cnt++) { 137 /* following bytes */ 138 wdata = msg->buf[cnt]; 139 ctrl = bus->i2c_period | (1 << 12) | (1 << 2); 140 141 if (cnt < msg->len - 1) 142 ctrl |= I2C_NOSTOP | I2C_EXTEND; 143 else if (joined_rlen) 144 ctrl |= I2C_NOSTOP; 145 146 cx_write(bus->reg_addr, addr); 147 cx_write(bus->reg_wdata, wdata); 148 cx_write(bus->reg_ctrl, ctrl); 149 150 retval = i2c_wait_done(i2c_adap); 151 if (retval < 0) 152 goto err; 153 154 if (retval == 0) 155 goto eio; 156 157 if (i2c_debug) { 158 dprintk(1, " %02x", msg->buf[cnt]); 159 if (!(ctrl & I2C_NOSTOP)) 160 dprintk(1, " >\n"); 161 } 162 } 163 164 return msg->len; 165 166 eio: 167 retval = -EIO; 168 err: 169 if (i2c_debug) 170 pr_err(" ERR: %d\n", retval); 171 return retval; 172 } 173 174 static int i2c_readbytes(struct i2c_adapter *i2c_adap, 175 const struct i2c_msg *msg, int joined) 176 { 177 struct cx25821_i2c *bus = i2c_adap->algo_data; 178 struct cx25821_dev *dev = bus->dev; 179 u32 ctrl, cnt; 180 int retval; 181 182 if (i2c_debug && !joined) 183 dprintk(1, "6-%s(msg->len=%d)\n", __func__, msg->len); 184 185 /* Deal with i2c probe functions with zero payload */ 186 if (msg->len == 0) { 187 cx_write(bus->reg_addr, msg->addr << 25); 188 cx_write(bus->reg_ctrl, bus->i2c_period | (1 << 2) | 1); 189 if (!i2c_wait_done(i2c_adap)) 190 return -EIO; 191 if (!i2c_slave_did_ack(i2c_adap)) 192 return -EIO; 193 194 dprintk(1, "%s(): returns 0\n", __func__); 195 return 0; 196 } 197 198 if (i2c_debug) { 199 if (joined) 200 dprintk(1, " R"); 201 else 202 dprintk(1, " <R %02x", (msg->addr << 1) + 1); 203 } 204 205 for (cnt = 0; cnt < msg->len; cnt++) { 206 207 ctrl = bus->i2c_period | (1 << 12) | (1 << 2) | 1; 208 209 if (cnt < msg->len - 1) 210 ctrl |= I2C_NOSTOP | I2C_EXTEND; 211 212 cx_write(bus->reg_addr, msg->addr << 25); 213 cx_write(bus->reg_ctrl, ctrl); 214 215 retval = i2c_wait_done(i2c_adap); 216 if (retval < 0) 217 goto err; 218 if (retval == 0) 219 goto eio; 220 msg->buf[cnt] = cx_read(bus->reg_rdata) & 0xff; 221 222 if (i2c_debug) { 223 dprintk(1, " %02x", msg->buf[cnt]); 224 if (!(ctrl & I2C_NOSTOP)) 225 dprintk(1, " >\n"); 226 } 227 } 228 229 return msg->len; 230 eio: 231 retval = -EIO; 232 err: 233 if (i2c_debug) 234 pr_err(" ERR: %d\n", retval); 235 return retval; 236 } 237 238 static int i2c_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs, int num) 239 { 240 struct cx25821_i2c *bus = i2c_adap->algo_data; 241 struct cx25821_dev *dev = bus->dev; 242 int i, retval = 0; 243 244 dprintk(1, "%s(num = %d)\n", __func__, num); 245 246 for (i = 0; i < num; i++) { 247 dprintk(1, "%s(num = %d) addr = 0x%02x len = 0x%x\n", 248 __func__, num, msgs[i].addr, msgs[i].len); 249 250 if (msgs[i].flags & I2C_M_RD) { 251 /* read */ 252 retval = i2c_readbytes(i2c_adap, &msgs[i], 0); 253 } else if (i + 1 < num && (msgs[i + 1].flags & I2C_M_RD) && 254 msgs[i].addr == msgs[i + 1].addr) { 255 /* write then read from same address */ 256 retval = i2c_sendbytes(i2c_adap, &msgs[i], 257 msgs[i + 1].len); 258 259 if (retval < 0) 260 goto err; 261 i++; 262 retval = i2c_readbytes(i2c_adap, &msgs[i], 1); 263 } else { 264 /* write */ 265 retval = i2c_sendbytes(i2c_adap, &msgs[i], 0); 266 } 267 268 if (retval < 0) 269 goto err; 270 } 271 return num; 272 273 err: 274 return retval; 275 } 276 277 278 static u32 cx25821_functionality(struct i2c_adapter *adap) 279 { 280 return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_I2C | I2C_FUNC_SMBUS_WORD_DATA | 281 I2C_FUNC_SMBUS_READ_WORD_DATA | I2C_FUNC_SMBUS_WRITE_WORD_DATA; 282 } 283 284 static struct i2c_algorithm cx25821_i2c_algo_template = { 285 .master_xfer = i2c_xfer, 286 .functionality = cx25821_functionality, 287 #ifdef NEED_ALGO_CONTROL 288 .algo_control = dummy_algo_control, 289 #endif 290 }; 291 292 static struct i2c_adapter cx25821_i2c_adap_template = { 293 .name = "cx25821", 294 .owner = THIS_MODULE, 295 .algo = &cx25821_i2c_algo_template, 296 }; 297 298 static struct i2c_client cx25821_i2c_client_template = { 299 .name = "cx25821 internal", 300 }; 301 302 /* init + register i2c adapter */ 303 int cx25821_i2c_register(struct cx25821_i2c *bus) 304 { 305 struct cx25821_dev *dev = bus->dev; 306 307 dprintk(1, "%s(bus = %d)\n", __func__, bus->nr); 308 309 bus->i2c_adap = cx25821_i2c_adap_template; 310 bus->i2c_client = cx25821_i2c_client_template; 311 bus->i2c_adap.dev.parent = &dev->pci->dev; 312 313 strlcpy(bus->i2c_adap.name, bus->dev->name, sizeof(bus->i2c_adap.name)); 314 315 bus->i2c_adap.algo_data = bus; 316 i2c_set_adapdata(&bus->i2c_adap, &dev->v4l2_dev); 317 i2c_add_adapter(&bus->i2c_adap); 318 319 bus->i2c_client.adapter = &bus->i2c_adap; 320 321 /* set up the I2c */ 322 bus->i2c_client.addr = (0x88 >> 1); 323 324 return bus->i2c_rc; 325 } 326 327 int cx25821_i2c_unregister(struct cx25821_i2c *bus) 328 { 329 i2c_del_adapter(&bus->i2c_adap); 330 return 0; 331 } 332 333 #if 0 /* Currently unused */ 334 static void cx25821_av_clk(struct cx25821_dev *dev, int enable) 335 { 336 /* write 0 to bus 2 addr 0x144 via i2x_xfer() */ 337 char buffer[3]; 338 struct i2c_msg msg; 339 dprintk(1, "%s(enabled = %d)\n", __func__, enable); 340 341 /* Register 0x144 */ 342 buffer[0] = 0x01; 343 buffer[1] = 0x44; 344 if (enable == 1) 345 buffer[2] = 0x05; 346 else 347 buffer[2] = 0x00; 348 349 msg.addr = 0x44; 350 msg.flags = I2C_M_TEN; 351 msg.len = 3; 352 msg.buf = buffer; 353 354 i2c_xfer(&dev->i2c_bus[0].i2c_adap, &msg, 1); 355 } 356 #endif 357 358 int cx25821_i2c_read(struct cx25821_i2c *bus, u16 reg_addr, int *value) 359 { 360 struct i2c_client *client = &bus->i2c_client; 361 int v = 0; 362 u8 addr[2] = { 0, 0 }; 363 u8 buf[4] = { 0, 0, 0, 0 }; 364 365 struct i2c_msg msgs[2] = { 366 { 367 .addr = client->addr, 368 .flags = 0, 369 .len = 2, 370 .buf = addr, 371 }, { 372 .addr = client->addr, 373 .flags = I2C_M_RD, 374 .len = 4, 375 .buf = buf, 376 } 377 }; 378 379 addr[0] = (reg_addr >> 8); 380 addr[1] = (reg_addr & 0xff); 381 msgs[0].addr = 0x44; 382 msgs[1].addr = 0x44; 383 384 i2c_xfer(client->adapter, msgs, 2); 385 386 v = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0]; 387 *value = v; 388 389 return v; 390 } 391 392 int cx25821_i2c_write(struct cx25821_i2c *bus, u16 reg_addr, int value) 393 { 394 struct i2c_client *client = &bus->i2c_client; 395 int retval = 0; 396 u8 buf[6] = { 0, 0, 0, 0, 0, 0 }; 397 398 struct i2c_msg msgs[1] = { 399 { 400 .addr = client->addr, 401 .flags = 0, 402 .len = 6, 403 .buf = buf, 404 } 405 }; 406 407 buf[0] = reg_addr >> 8; 408 buf[1] = reg_addr & 0xff; 409 buf[5] = (value >> 24) & 0xff; 410 buf[4] = (value >> 16) & 0xff; 411 buf[3] = (value >> 8) & 0xff; 412 buf[2] = value & 0xff; 413 client->flags = 0; 414 msgs[0].addr = 0x44; 415 416 retval = i2c_xfer(client->adapter, msgs, 1); 417 418 return retval; 419 } 420