1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Driver for the Conexant CX25821 PCIe bridge 4 * 5 * Copyright (C) 2009 Conexant Systems Inc. 6 * Authors <shu.lin@conexant.com>, <hiep.huynh@conexant.com> 7 * Based on Steven Toth <stoth@linuxtv.org> cx23885 driver 8 */ 9 10 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 11 12 #include <linux/module.h> 13 #include <linux/i2c.h> 14 #include "cx25821.h" 15 16 static unsigned int i2c_debug; 17 module_param(i2c_debug, int, 0644); 18 MODULE_PARM_DESC(i2c_debug, "enable debug messages [i2c]"); 19 20 static unsigned int i2c_scan; 21 module_param(i2c_scan, int, 0444); 22 MODULE_PARM_DESC(i2c_scan, "scan i2c bus at insmod time"); 23 24 #define dprintk(level, fmt, arg...) \ 25 do { \ 26 if (i2c_debug >= level) \ 27 printk(KERN_DEBUG "%s/0: " fmt, dev->name, ##arg); \ 28 } while (0) 29 30 #define I2C_WAIT_DELAY 32 31 #define I2C_WAIT_RETRY 64 32 33 #define I2C_EXTEND (1 << 3) 34 #define I2C_NOSTOP (1 << 4) 35 36 static inline int i2c_slave_did_ack(struct i2c_adapter *i2c_adap) 37 { 38 struct cx25821_i2c *bus = i2c_adap->algo_data; 39 struct cx25821_dev *dev = bus->dev; 40 return cx_read(bus->reg_stat) & 0x01; 41 } 42 43 static inline int i2c_is_busy(struct i2c_adapter *i2c_adap) 44 { 45 struct cx25821_i2c *bus = i2c_adap->algo_data; 46 struct cx25821_dev *dev = bus->dev; 47 return cx_read(bus->reg_stat) & 0x02 ? 1 : 0; 48 } 49 50 static int i2c_wait_done(struct i2c_adapter *i2c_adap) 51 { 52 int count; 53 54 for (count = 0; count < I2C_WAIT_RETRY; count++) { 55 if (!i2c_is_busy(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 int i2c_sendbytes(struct i2c_adapter *i2c_adap, 67 const struct i2c_msg *msg, int joined_rlen) 68 { 69 struct cx25821_i2c *bus = i2c_adap->algo_data; 70 struct cx25821_dev *dev = bus->dev; 71 u32 wdata, addr, ctrl; 72 int retval, cnt; 73 74 if (joined_rlen) 75 dprintk(1, "%s(msg->wlen=%d, nextmsg->rlen=%d)\n", __func__, 76 msg->len, joined_rlen); 77 else 78 dprintk(1, "%s(msg->len=%d)\n", __func__, msg->len); 79 80 /* Deal with i2c probe functions with zero payload */ 81 if (msg->len == 0) { 82 cx_write(bus->reg_addr, msg->addr << 25); 83 cx_write(bus->reg_ctrl, bus->i2c_period | (1 << 2)); 84 85 if (!i2c_wait_done(i2c_adap)) 86 return -EIO; 87 88 if (!i2c_slave_did_ack(i2c_adap)) 89 return -EIO; 90 91 dprintk(1, "%s(): returns 0\n", __func__); 92 return 0; 93 } 94 95 /* dev, reg + first byte */ 96 addr = (msg->addr << 25) | msg->buf[0]; 97 wdata = msg->buf[0]; 98 99 ctrl = bus->i2c_period | (1 << 12) | (1 << 2); 100 101 if (msg->len > 1) 102 ctrl |= I2C_NOSTOP | I2C_EXTEND; 103 else if (joined_rlen) 104 ctrl |= I2C_NOSTOP; 105 106 cx_write(bus->reg_addr, addr); 107 cx_write(bus->reg_wdata, wdata); 108 cx_write(bus->reg_ctrl, ctrl); 109 110 retval = i2c_wait_done(i2c_adap); 111 if (retval < 0) 112 goto err; 113 114 if (retval == 0) 115 goto eio; 116 117 if (i2c_debug) { 118 if (!(ctrl & I2C_NOSTOP)) 119 printk(" >\n"); 120 } 121 122 for (cnt = 1; cnt < msg->len; cnt++) { 123 /* following bytes */ 124 wdata = msg->buf[cnt]; 125 ctrl = bus->i2c_period | (1 << 12) | (1 << 2); 126 127 if (cnt < msg->len - 1) 128 ctrl |= I2C_NOSTOP | I2C_EXTEND; 129 else if (joined_rlen) 130 ctrl |= I2C_NOSTOP; 131 132 cx_write(bus->reg_addr, addr); 133 cx_write(bus->reg_wdata, wdata); 134 cx_write(bus->reg_ctrl, ctrl); 135 136 retval = i2c_wait_done(i2c_adap); 137 if (retval < 0) 138 goto err; 139 140 if (retval == 0) 141 goto eio; 142 143 if (i2c_debug) { 144 dprintk(1, " %02x", msg->buf[cnt]); 145 if (!(ctrl & I2C_NOSTOP)) 146 dprintk(1, " >\n"); 147 } 148 } 149 150 return msg->len; 151 152 eio: 153 retval = -EIO; 154 err: 155 if (i2c_debug) 156 pr_err(" ERR: %d\n", retval); 157 return retval; 158 } 159 160 static int i2c_readbytes(struct i2c_adapter *i2c_adap, 161 const struct i2c_msg *msg, int joined) 162 { 163 struct cx25821_i2c *bus = i2c_adap->algo_data; 164 struct cx25821_dev *dev = bus->dev; 165 u32 ctrl, cnt; 166 int retval; 167 168 if (i2c_debug && !joined) 169 dprintk(1, "6-%s(msg->len=%d)\n", __func__, msg->len); 170 171 /* Deal with i2c probe functions with zero payload */ 172 if (msg->len == 0) { 173 cx_write(bus->reg_addr, msg->addr << 25); 174 cx_write(bus->reg_ctrl, bus->i2c_period | (1 << 2) | 1); 175 if (!i2c_wait_done(i2c_adap)) 176 return -EIO; 177 if (!i2c_slave_did_ack(i2c_adap)) 178 return -EIO; 179 180 dprintk(1, "%s(): returns 0\n", __func__); 181 return 0; 182 } 183 184 if (i2c_debug) { 185 if (joined) 186 dprintk(1, " R"); 187 else 188 dprintk(1, " <R %02x", (msg->addr << 1) + 1); 189 } 190 191 for (cnt = 0; cnt < msg->len; cnt++) { 192 193 ctrl = bus->i2c_period | (1 << 12) | (1 << 2) | 1; 194 195 if (cnt < msg->len - 1) 196 ctrl |= I2C_NOSTOP | I2C_EXTEND; 197 198 cx_write(bus->reg_addr, msg->addr << 25); 199 cx_write(bus->reg_ctrl, ctrl); 200 201 retval = i2c_wait_done(i2c_adap); 202 if (retval < 0) 203 goto err; 204 if (retval == 0) 205 goto eio; 206 msg->buf[cnt] = cx_read(bus->reg_rdata) & 0xff; 207 208 if (i2c_debug) { 209 dprintk(1, " %02x", msg->buf[cnt]); 210 if (!(ctrl & I2C_NOSTOP)) 211 dprintk(1, " >\n"); 212 } 213 } 214 215 return msg->len; 216 eio: 217 retval = -EIO; 218 err: 219 if (i2c_debug) 220 pr_err(" ERR: %d\n", retval); 221 return retval; 222 } 223 224 static int i2c_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs, int num) 225 { 226 struct cx25821_i2c *bus = i2c_adap->algo_data; 227 struct cx25821_dev *dev = bus->dev; 228 int i, retval = 0; 229 230 dprintk(1, "%s(num = %d)\n", __func__, num); 231 232 for (i = 0; i < num; i++) { 233 dprintk(1, "%s(num = %d) addr = 0x%02x len = 0x%x\n", 234 __func__, num, msgs[i].addr, msgs[i].len); 235 236 if (msgs[i].flags & I2C_M_RD) { 237 /* read */ 238 retval = i2c_readbytes(i2c_adap, &msgs[i], 0); 239 } else if (i + 1 < num && (msgs[i + 1].flags & I2C_M_RD) && 240 msgs[i].addr == msgs[i + 1].addr) { 241 /* write then read from same address */ 242 retval = i2c_sendbytes(i2c_adap, &msgs[i], 243 msgs[i + 1].len); 244 245 if (retval < 0) 246 goto err; 247 i++; 248 retval = i2c_readbytes(i2c_adap, &msgs[i], 1); 249 } else { 250 /* write */ 251 retval = i2c_sendbytes(i2c_adap, &msgs[i], 0); 252 } 253 254 if (retval < 0) 255 goto err; 256 } 257 return num; 258 259 err: 260 return retval; 261 } 262 263 264 static u32 cx25821_functionality(struct i2c_adapter *adap) 265 { 266 return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_I2C | I2C_FUNC_SMBUS_WORD_DATA | 267 I2C_FUNC_SMBUS_READ_WORD_DATA | I2C_FUNC_SMBUS_WRITE_WORD_DATA; 268 } 269 270 static const struct i2c_algorithm cx25821_i2c_algo_template = { 271 .master_xfer = i2c_xfer, 272 .functionality = cx25821_functionality, 273 #ifdef NEED_ALGO_CONTROL 274 .algo_control = dummy_algo_control, 275 #endif 276 }; 277 278 static const struct i2c_adapter cx25821_i2c_adap_template = { 279 .name = "cx25821", 280 .owner = THIS_MODULE, 281 .algo = &cx25821_i2c_algo_template, 282 }; 283 284 static const struct i2c_client cx25821_i2c_client_template = { 285 .name = "cx25821 internal", 286 }; 287 288 /* init + register i2c adapter */ 289 int cx25821_i2c_register(struct cx25821_i2c *bus) 290 { 291 struct cx25821_dev *dev = bus->dev; 292 293 dprintk(1, "%s(bus = %d)\n", __func__, bus->nr); 294 295 bus->i2c_adap = cx25821_i2c_adap_template; 296 bus->i2c_client = cx25821_i2c_client_template; 297 bus->i2c_adap.dev.parent = &dev->pci->dev; 298 299 strscpy(bus->i2c_adap.name, bus->dev->name, sizeof(bus->i2c_adap.name)); 300 301 bus->i2c_adap.algo_data = bus; 302 i2c_set_adapdata(&bus->i2c_adap, &dev->v4l2_dev); 303 i2c_add_adapter(&bus->i2c_adap); 304 305 bus->i2c_client.adapter = &bus->i2c_adap; 306 307 /* set up the I2c */ 308 bus->i2c_client.addr = (0x88 >> 1); 309 310 return bus->i2c_rc; 311 } 312 313 int cx25821_i2c_unregister(struct cx25821_i2c *bus) 314 { 315 i2c_del_adapter(&bus->i2c_adap); 316 return 0; 317 } 318 319 #if 0 /* Currently unused */ 320 static void cx25821_av_clk(struct cx25821_dev *dev, int enable) 321 { 322 /* write 0 to bus 2 addr 0x144 via i2x_xfer() */ 323 char buffer[3]; 324 struct i2c_msg msg; 325 dprintk(1, "%s(enabled = %d)\n", __func__, enable); 326 327 /* Register 0x144 */ 328 buffer[0] = 0x01; 329 buffer[1] = 0x44; 330 if (enable == 1) 331 buffer[2] = 0x05; 332 else 333 buffer[2] = 0x00; 334 335 msg.addr = 0x44; 336 msg.flags = I2C_M_TEN; 337 msg.len = 3; 338 msg.buf = buffer; 339 340 i2c_xfer(&dev->i2c_bus[0].i2c_adap, &msg, 1); 341 } 342 #endif 343 344 int cx25821_i2c_read(struct cx25821_i2c *bus, u16 reg_addr, int *value) 345 { 346 struct i2c_client *client = &bus->i2c_client; 347 int v = 0; 348 u8 addr[2] = { 0, 0 }; 349 u8 buf[4] = { 0, 0, 0, 0 }; 350 351 struct i2c_msg msgs[2] = { 352 { 353 .addr = client->addr, 354 .flags = 0, 355 .len = 2, 356 .buf = addr, 357 }, { 358 .addr = client->addr, 359 .flags = I2C_M_RD, 360 .len = 4, 361 .buf = buf, 362 } 363 }; 364 365 addr[0] = (reg_addr >> 8); 366 addr[1] = (reg_addr & 0xff); 367 msgs[0].addr = 0x44; 368 msgs[1].addr = 0x44; 369 370 i2c_xfer(client->adapter, msgs, 2); 371 372 v = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0]; 373 *value = v; 374 375 return v; 376 } 377 378 int cx25821_i2c_write(struct cx25821_i2c *bus, u16 reg_addr, int value) 379 { 380 struct i2c_client *client = &bus->i2c_client; 381 int retval = 0; 382 u8 buf[6] = { 0, 0, 0, 0, 0, 0 }; 383 384 struct i2c_msg msgs[1] = { 385 { 386 .addr = client->addr, 387 .flags = 0, 388 .len = 6, 389 .buf = buf, 390 } 391 }; 392 393 buf[0] = reg_addr >> 8; 394 buf[1] = reg_addr & 0xff; 395 buf[5] = (value >> 24) & 0xff; 396 buf[4] = (value >> 16) & 0xff; 397 buf[3] = (value >> 8) & 0xff; 398 buf[2] = value & 0xff; 399 client->flags = 0; 400 msgs[0].addr = 0x44; 401 402 retval = i2c_xfer(client->adapter, msgs, 1); 403 404 return retval; 405 } 406