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 "cx25821.h" 27 #include <linux/i2c.h> 28 29 static unsigned int i2c_debug; 30 module_param(i2c_debug, int, 0644); 31 MODULE_PARM_DESC(i2c_debug, "enable debug messages [i2c]"); 32 33 static unsigned int i2c_scan; 34 module_param(i2c_scan, int, 0444); 35 MODULE_PARM_DESC(i2c_scan, "scan i2c bus at insmod time"); 36 37 #define dprintk(level, fmt, arg...) \ 38 do { \ 39 if (i2c_debug >= level) \ 40 printk(KERN_DEBUG "%s/0: " fmt, dev->name, ##arg); \ 41 } while (0) 42 43 #define I2C_WAIT_DELAY 32 44 #define I2C_WAIT_RETRY 64 45 46 #define I2C_EXTEND (1 << 3) 47 #define I2C_NOSTOP (1 << 4) 48 49 static inline int i2c_slave_did_ack(struct i2c_adapter *i2c_adap) 50 { 51 struct cx25821_i2c *bus = i2c_adap->algo_data; 52 struct cx25821_dev *dev = bus->dev; 53 return cx_read(bus->reg_stat) & 0x01; 54 } 55 56 static inline int i2c_is_busy(struct i2c_adapter *i2c_adap) 57 { 58 struct cx25821_i2c *bus = i2c_adap->algo_data; 59 struct cx25821_dev *dev = bus->dev; 60 return cx_read(bus->reg_stat) & 0x02 ? 1 : 0; 61 } 62 63 static int i2c_wait_done(struct i2c_adapter *i2c_adap) 64 { 65 int count; 66 67 for (count = 0; count < I2C_WAIT_RETRY; count++) { 68 if (!i2c_is_busy(i2c_adap)) 69 break; 70 udelay(I2C_WAIT_DELAY); 71 } 72 73 if (I2C_WAIT_RETRY == count) 74 return 0; 75 76 return 1; 77 } 78 79 static int i2c_sendbytes(struct i2c_adapter *i2c_adap, 80 const struct i2c_msg *msg, int joined_rlen) 81 { 82 struct cx25821_i2c *bus = i2c_adap->algo_data; 83 struct cx25821_dev *dev = bus->dev; 84 u32 wdata, addr, ctrl; 85 int retval, cnt; 86 87 if (joined_rlen) 88 dprintk(1, "%s(msg->wlen=%d, nextmsg->rlen=%d)\n", __func__, 89 msg->len, joined_rlen); 90 else 91 dprintk(1, "%s(msg->len=%d)\n", __func__, msg->len); 92 93 /* Deal with i2c probe functions with zero payload */ 94 if (msg->len == 0) { 95 cx_write(bus->reg_addr, msg->addr << 25); 96 cx_write(bus->reg_ctrl, bus->i2c_period | (1 << 2)); 97 98 if (!i2c_wait_done(i2c_adap)) 99 return -EIO; 100 101 if (!i2c_slave_did_ack(i2c_adap)) 102 return -EIO; 103 104 dprintk(1, "%s(): returns 0\n", __func__); 105 return 0; 106 } 107 108 /* dev, reg + first byte */ 109 addr = (msg->addr << 25) | msg->buf[0]; 110 wdata = msg->buf[0]; 111 112 ctrl = bus->i2c_period | (1 << 12) | (1 << 2); 113 114 if (msg->len > 1) 115 ctrl |= I2C_NOSTOP | I2C_EXTEND; 116 else if (joined_rlen) 117 ctrl |= I2C_NOSTOP; 118 119 cx_write(bus->reg_addr, addr); 120 cx_write(bus->reg_wdata, wdata); 121 cx_write(bus->reg_ctrl, ctrl); 122 123 retval = i2c_wait_done(i2c_adap); 124 if (retval < 0) 125 goto err; 126 127 if (retval == 0) 128 goto eio; 129 130 if (i2c_debug) { 131 if (!(ctrl & I2C_NOSTOP)) 132 printk(" >\n"); 133 } 134 135 for (cnt = 1; cnt < msg->len; cnt++) { 136 /* following bytes */ 137 wdata = msg->buf[cnt]; 138 ctrl = bus->i2c_period | (1 << 12) | (1 << 2); 139 140 if (cnt < msg->len - 1) 141 ctrl |= I2C_NOSTOP | I2C_EXTEND; 142 else if (joined_rlen) 143 ctrl |= I2C_NOSTOP; 144 145 cx_write(bus->reg_addr, addr); 146 cx_write(bus->reg_wdata, wdata); 147 cx_write(bus->reg_ctrl, ctrl); 148 149 retval = i2c_wait_done(i2c_adap); 150 if (retval < 0) 151 goto err; 152 153 if (retval == 0) 154 goto eio; 155 156 if (i2c_debug) { 157 dprintk(1, " %02x", msg->buf[cnt]); 158 if (!(ctrl & I2C_NOSTOP)) 159 dprintk(1, " >\n"); 160 } 161 } 162 163 return msg->len; 164 165 eio: 166 retval = -EIO; 167 err: 168 if (i2c_debug) 169 pr_err(" ERR: %d\n", retval); 170 return retval; 171 } 172 173 static int i2c_readbytes(struct i2c_adapter *i2c_adap, 174 const struct i2c_msg *msg, int joined) 175 { 176 struct cx25821_i2c *bus = i2c_adap->algo_data; 177 struct cx25821_dev *dev = bus->dev; 178 u32 ctrl, cnt; 179 int retval; 180 181 if (i2c_debug && !joined) 182 dprintk(1, "6-%s(msg->len=%d)\n", __func__, msg->len); 183 184 /* Deal with i2c probe functions with zero payload */ 185 if (msg->len == 0) { 186 cx_write(bus->reg_addr, msg->addr << 25); 187 cx_write(bus->reg_ctrl, bus->i2c_period | (1 << 2) | 1); 188 if (!i2c_wait_done(i2c_adap)) 189 return -EIO; 190 if (!i2c_slave_did_ack(i2c_adap)) 191 return -EIO; 192 193 dprintk(1, "%s(): returns 0\n", __func__); 194 return 0; 195 } 196 197 if (i2c_debug) { 198 if (joined) 199 dprintk(1, " R"); 200 else 201 dprintk(1, " <R %02x", (msg->addr << 1) + 1); 202 } 203 204 for (cnt = 0; cnt < msg->len; cnt++) { 205 206 ctrl = bus->i2c_period | (1 << 12) | (1 << 2) | 1; 207 208 if (cnt < msg->len - 1) 209 ctrl |= I2C_NOSTOP | I2C_EXTEND; 210 211 cx_write(bus->reg_addr, msg->addr << 25); 212 cx_write(bus->reg_ctrl, ctrl); 213 214 retval = i2c_wait_done(i2c_adap); 215 if (retval < 0) 216 goto err; 217 if (retval == 0) 218 goto eio; 219 msg->buf[cnt] = cx_read(bus->reg_rdata) & 0xff; 220 221 if (i2c_debug) { 222 dprintk(1, " %02x", msg->buf[cnt]); 223 if (!(ctrl & I2C_NOSTOP)) 224 dprintk(1, " >\n"); 225 } 226 } 227 228 return msg->len; 229 eio: 230 retval = -EIO; 231 err: 232 if (i2c_debug) 233 pr_err(" ERR: %d\n", retval); 234 return retval; 235 } 236 237 static int i2c_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs, int num) 238 { 239 struct cx25821_i2c *bus = i2c_adap->algo_data; 240 struct cx25821_dev *dev = bus->dev; 241 int i, retval = 0; 242 243 dprintk(1, "%s(num = %d)\n", __func__, num); 244 245 for (i = 0; i < num; i++) { 246 dprintk(1, "%s(num = %d) addr = 0x%02x len = 0x%x\n", 247 __func__, num, msgs[i].addr, msgs[i].len); 248 249 if (msgs[i].flags & I2C_M_RD) { 250 /* read */ 251 retval = i2c_readbytes(i2c_adap, &msgs[i], 0); 252 } else if (i + 1 < num && (msgs[i + 1].flags & I2C_M_RD) && 253 msgs[i].addr == msgs[i + 1].addr) { 254 /* write then read from same address */ 255 retval = i2c_sendbytes(i2c_adap, &msgs[i], 256 msgs[i + 1].len); 257 258 if (retval < 0) 259 goto err; 260 i++; 261 retval = i2c_readbytes(i2c_adap, &msgs[i], 1); 262 } else { 263 /* write */ 264 retval = i2c_sendbytes(i2c_adap, &msgs[i], 0); 265 } 266 267 if (retval < 0) 268 goto err; 269 } 270 return num; 271 272 err: 273 return retval; 274 } 275 276 277 static u32 cx25821_functionality(struct i2c_adapter *adap) 278 { 279 return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_I2C | I2C_FUNC_SMBUS_WORD_DATA | 280 I2C_FUNC_SMBUS_READ_WORD_DATA | I2C_FUNC_SMBUS_WRITE_WORD_DATA; 281 } 282 283 static struct i2c_algorithm cx25821_i2c_algo_template = { 284 .master_xfer = i2c_xfer, 285 .functionality = cx25821_functionality, 286 #ifdef NEED_ALGO_CONTROL 287 .algo_control = dummy_algo_control, 288 #endif 289 }; 290 291 static struct i2c_adapter cx25821_i2c_adap_template = { 292 .name = "cx25821", 293 .owner = THIS_MODULE, 294 .algo = &cx25821_i2c_algo_template, 295 }; 296 297 static struct i2c_client cx25821_i2c_client_template = { 298 .name = "cx25821 internal", 299 }; 300 301 /* init + register i2c adapter */ 302 int cx25821_i2c_register(struct cx25821_i2c *bus) 303 { 304 struct cx25821_dev *dev = bus->dev; 305 306 dprintk(1, "%s(bus = %d)\n", __func__, bus->nr); 307 308 bus->i2c_adap = cx25821_i2c_adap_template; 309 bus->i2c_client = cx25821_i2c_client_template; 310 bus->i2c_adap.dev.parent = &dev->pci->dev; 311 312 strlcpy(bus->i2c_adap.name, bus->dev->name, sizeof(bus->i2c_adap.name)); 313 314 bus->i2c_adap.algo_data = bus; 315 i2c_set_adapdata(&bus->i2c_adap, &dev->v4l2_dev); 316 i2c_add_adapter(&bus->i2c_adap); 317 318 bus->i2c_client.adapter = &bus->i2c_adap; 319 320 /* set up the I2c */ 321 bus->i2c_client.addr = (0x88 >> 1); 322 323 return bus->i2c_rc; 324 } 325 326 int cx25821_i2c_unregister(struct cx25821_i2c *bus) 327 { 328 i2c_del_adapter(&bus->i2c_adap); 329 return 0; 330 } 331 332 #if 0 /* Currently unused */ 333 static void cx25821_av_clk(struct cx25821_dev *dev, int enable) 334 { 335 /* write 0 to bus 2 addr 0x144 via i2x_xfer() */ 336 char buffer[3]; 337 struct i2c_msg msg; 338 dprintk(1, "%s(enabled = %d)\n", __func__, enable); 339 340 /* Register 0x144 */ 341 buffer[0] = 0x01; 342 buffer[1] = 0x44; 343 if (enable == 1) 344 buffer[2] = 0x05; 345 else 346 buffer[2] = 0x00; 347 348 msg.addr = 0x44; 349 msg.flags = I2C_M_TEN; 350 msg.len = 3; 351 msg.buf = buffer; 352 353 i2c_xfer(&dev->i2c_bus[0].i2c_adap, &msg, 1); 354 } 355 #endif 356 357 int cx25821_i2c_read(struct cx25821_i2c *bus, u16 reg_addr, int *value) 358 { 359 struct i2c_client *client = &bus->i2c_client; 360 int v = 0; 361 u8 addr[2] = { 0, 0 }; 362 u8 buf[4] = { 0, 0, 0, 0 }; 363 364 struct i2c_msg msgs[2] = { 365 { 366 .addr = client->addr, 367 .flags = 0, 368 .len = 2, 369 .buf = addr, 370 }, { 371 .addr = client->addr, 372 .flags = I2C_M_RD, 373 .len = 4, 374 .buf = buf, 375 } 376 }; 377 378 addr[0] = (reg_addr >> 8); 379 addr[1] = (reg_addr & 0xff); 380 msgs[0].addr = 0x44; 381 msgs[1].addr = 0x44; 382 383 i2c_xfer(client->adapter, msgs, 2); 384 385 v = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0]; 386 *value = v; 387 388 return v; 389 } 390 391 int cx25821_i2c_write(struct cx25821_i2c *bus, u16 reg_addr, int value) 392 { 393 struct i2c_client *client = &bus->i2c_client; 394 int retval = 0; 395 u8 buf[6] = { 0, 0, 0, 0, 0, 0 }; 396 397 struct i2c_msg msgs[1] = { 398 { 399 .addr = client->addr, 400 .flags = 0, 401 .len = 6, 402 .buf = buf, 403 } 404 }; 405 406 buf[0] = reg_addr >> 8; 407 buf[1] = reg_addr & 0xff; 408 buf[5] = (value >> 24) & 0xff; 409 buf[4] = (value >> 16) & 0xff; 410 buf[3] = (value >> 8) & 0xff; 411 buf[2] = value & 0xff; 412 client->flags = 0; 413 msgs[0].addr = 0x44; 414 415 retval = i2c_xfer(client->adapter, msgs, 1); 416 417 return retval; 418 } 419