drivers/media/usb/au0828/au0828-i2c.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  Driver for the Auvitek AU0828 USB bridge
   4  *
   5  *  Copyright (c) 2008 Steven Toth <stoth@linuxtv.org>
   6  */
   7
   8 #include "au0828.h"
   9
  10 #include <linux/module.h>
  11 #include <linux/moduleparam.h>
  12 #include <linux/init.h>
  13 #include <linux/delay.h>
  14 #include <linux/io.h>
  15
  16 #include "media/tuner.h"
  17 #include <media/v4l2-common.h>
  18
  19 static int i2c_scan;
  20 module_param(i2c_scan, int, 0444);
  21 MODULE_PARM_DESC(i2c_scan, "scan i2c bus at insmod time");
  22
  23 #define I2C_WAIT_DELAY 25
  24 #define I2C_WAIT_RETRY 1000
  25
  26 static inline int i2c_slave_did_write_ack(struct i2c_adapter *i2c_adap)
  27 {
  28         struct au0828_dev *dev = i2c_adap->algo_data;
  29         return au0828_read(dev, AU0828_I2C_STATUS_201) &
  30                 AU0828_I2C_STATUS_NO_WRITE_ACK ? 0 : 1;
  31 }
  32
  33 static inline int i2c_slave_did_read_ack(struct i2c_adapter *i2c_adap)
  34 {
  35         struct au0828_dev *dev = i2c_adap->algo_data;
  36         return au0828_read(dev, AU0828_I2C_STATUS_201) &
  37                 AU0828_I2C_STATUS_NO_READ_ACK ? 0 : 1;
  38 }
  39
  40 static int i2c_wait_read_ack(struct i2c_adapter *i2c_adap)
  41 {
  42         int count;
  43
  44         for (count = 0; count < I2C_WAIT_RETRY; count++) {
  45                 if (!i2c_slave_did_read_ack(i2c_adap))
  46                         break;
  47                 udelay(I2C_WAIT_DELAY);
  48         }
  49
  50         if (I2C_WAIT_RETRY == count)
  51                 return 0;
  52
  53         return 1;
  54 }
  55
  56 static inline int i2c_is_read_busy(struct i2c_adapter *i2c_adap)
  57 {
  58         struct au0828_dev *dev = i2c_adap->algo_data;
  59         return au0828_read(dev, AU0828_I2C_STATUS_201) &
  60                 AU0828_I2C_STATUS_READ_DONE ? 0 : 1;
  61 }
  62
  63 static int i2c_wait_read_done(struct i2c_adapter *i2c_adap)
  64 {
  65         int count;
  66
  67         for (count = 0; count < I2C_WAIT_RETRY; count++) {
  68                 if (!i2c_is_read_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 inline int i2c_is_write_done(struct i2c_adapter *i2c_adap)
  80 {
  81         struct au0828_dev *dev = i2c_adap->algo_data;
  82         return au0828_read(dev, AU0828_I2C_STATUS_201) &
  83                 AU0828_I2C_STATUS_WRITE_DONE ? 1 : 0;
  84 }
  85
  86 static int i2c_wait_write_done(struct i2c_adapter *i2c_adap)
  87 {
  88         int count;
  89
  90         for (count = 0; count < I2C_WAIT_RETRY; count++) {
  91                 if (i2c_is_write_done(i2c_adap))
  92                         break;
  93                 udelay(I2C_WAIT_DELAY);
  94         }
  95
  96         if (I2C_WAIT_RETRY == count)
  97                 return 0;
  98
  99         return 1;
 100 }
 101
 102 static inline int i2c_is_busy(struct i2c_adapter *i2c_adap)
 103 {
 104         struct au0828_dev *dev = i2c_adap->algo_data;
 105         return au0828_read(dev, AU0828_I2C_STATUS_201) &
 106                 AU0828_I2C_STATUS_BUSY ? 1 : 0;
 107 }
 108
 109 static int i2c_wait_done(struct i2c_adapter *i2c_adap)
 110 {
 111         int count;
 112
 113         for (count = 0; count < I2C_WAIT_RETRY; count++) {
 114                 if (!i2c_is_busy(i2c_adap))
 115                         break;
 116                 udelay(I2C_WAIT_DELAY);
 117         }
 118
 119         if (I2C_WAIT_RETRY == count)
 120                 return 0;
 121
 122         return 1;
 123 }
 124
 125 /* FIXME: Implement join handling correctly */
 126 static int i2c_sendbytes(struct i2c_adapter *i2c_adap,
 127         const struct i2c_msg *msg, int joined_rlen)
 128 {
 129         int i, strobe = 0;
 130         struct au0828_dev *dev = i2c_adap->algo_data;
 131         u8 i2c_speed = dev->board.i2c_clk_divider;
 132
 133         dprintk(4, "%s()\n", __func__);
 134
 135         au0828_write(dev, AU0828_I2C_MULTIBYTE_MODE_2FF, 0x01);
 136
 137         if (((dev->board.tuner_type == TUNER_XC5000) ||
 138              (dev->board.tuner_type == TUNER_XC5000C)) &&
 139             (dev->board.tuner_addr == msg->addr)) {
 140                 /*
 141                  * Due to I2C clock stretch, we need to use a lower speed
 142                  * on xc5000 for commands. However, firmware transfer can
 143                  * speed up to 400 KHz.
 144                  */
 145                 if (msg->len == 64)
 146                         i2c_speed = AU0828_I2C_CLK_250KHZ;
 147                 else
 148                         i2c_speed = AU0828_I2C_CLK_20KHZ;
 149         }
 150         /* Set the I2C clock */
 151         au0828_write(dev, AU0828_I2C_CLK_DIVIDER_202, i2c_speed);
 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 */
 216 static 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         u8 i2c_speed = dev->board.i2c_clk_divider;
 221         int i;
 222
 223         dprintk(4, "%s()\n", __func__);
 224
 225         au0828_write(dev, AU0828_I2C_MULTIBYTE_MODE_2FF, 0x01);
 226
 227         /*
 228          * Due to xc5000c clock stretch, we cannot use full speed at
 229          * readings from xc5000, as otherwise they'll fail.
 230          */
 231         if (((dev->board.tuner_type == TUNER_XC5000) ||
 232              (dev->board.tuner_type == TUNER_XC5000C)) &&
 233             (dev->board.tuner_addr == msg->addr))
 234                 i2c_speed = AU0828_I2C_CLK_20KHZ;
 235
 236         /* Set the I2C clock */
 237         au0828_write(dev, AU0828_I2C_CLK_DIVIDER_202, i2c_speed);
 238
 239         /* Hardware needs 8 bit addresses */
 240         au0828_write(dev, AU0828_I2C_DEST_ADDR_203, msg->addr << 1);
 241
 242         dprintk(4, " RECV:\n");
 243
 244         /* Deal with i2c_scan */
 245         if (msg->len == 0) {
 246                 au0828_write(dev, AU0828_I2C_TRIGGER_200,
 247                              AU0828_I2C_TRIGGER_READ);
 248
 249                 if (i2c_wait_read_ack(i2c_adap))
 250                         return -EIO;
 251                 return 0;
 252         }
 253
 254         for (i = 0; i < msg->len;) {
 255
 256                 i++;
 257
 258                 if (i < msg->len)
 259                         au0828_write(dev, AU0828_I2C_TRIGGER_200,
 260                                      AU0828_I2C_TRIGGER_READ |
 261                                      AU0828_I2C_TRIGGER_HOLD);
 262                 else
 263                         au0828_write(dev, AU0828_I2C_TRIGGER_200,
 264                                      AU0828_I2C_TRIGGER_READ);
 265
 266                 if (!i2c_wait_read_done(i2c_adap))
 267                         return -EIO;
 268
 269                 msg->buf[i-1] = au0828_read(dev, AU0828_I2C_READ_FIFO_209) &
 270                         0xff;
 271
 272                 dprintk(4, " %02x\n", msg->buf[i-1]);
 273         }
 274         if (!i2c_wait_done(i2c_adap))
 275                 return -EIO;
 276
 277         dprintk(4, "\n");
 278
 279         return msg->len;
 280 }
 281
 282 static int i2c_xfer(struct i2c_adapter *i2c_adap,
 283                     struct i2c_msg *msgs, int num)
 284 {
 285         int i, retval = 0;
 286
 287         dprintk(4, "%s(num = %d)\n", __func__, num);
 288
 289         for (i = 0; i < num; i++) {
 290                 dprintk(4, "%s(num = %d) addr = 0x%02x  len = 0x%x\n",
 291                         __func__, num, msgs[i].addr, msgs[i].len);
 292                 if (msgs[i].flags & I2C_M_RD) {
 293                         /* read */
 294                         retval = i2c_readbytes(i2c_adap, &msgs[i], 0);
 295                 } else if (i + 1 < num && (msgs[i + 1].flags & I2C_M_RD) &&
 296                            msgs[i].addr == msgs[i + 1].addr) {
 297                         /* write then read from same address */
 298                         retval = i2c_sendbytes(i2c_adap, &msgs[i],
 299                                                msgs[i + 1].len);
 300                         if (retval < 0)
 301                                 goto err;
 302                         i++;
 303                         retval = i2c_readbytes(i2c_adap, &msgs[i], 1);
 304                 } else {
 305                         /* write */
 306                         retval = i2c_sendbytes(i2c_adap, &msgs[i], 0);
 307                 }
 308                 if (retval < 0)
 309                         goto err;
 310         }
 311         return num;
 312
 313 err:
 314         return retval;
 315 }
 316
 317 static u32 au0828_functionality(struct i2c_adapter *adap)
 318 {
 319         return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_I2C;
 320 }
 321
 322 static const struct i2c_algorithm au0828_i2c_algo_template = {
 323         .master_xfer    = i2c_xfer,
 324         .functionality  = au0828_functionality,
 325 };
 326
 327 /* ----------------------------------------------------------------------- */
 328
 329 static const struct i2c_adapter au0828_i2c_adap_template = {
 330         .name              = KBUILD_MODNAME,
 331         .owner             = THIS_MODULE,
 332         .algo              = &au0828_i2c_algo_template,
 333 };
 334
 335 static const struct i2c_client au0828_i2c_client_template = {
 336         .name   = "au0828 internal",
 337 };
 338
 339 static char *i2c_devs[128] = {
 340         [0x8e >> 1] = "au8522",
 341         [0xa0 >> 1] = "eeprom",
 342         [0xc2 >> 1] = "tuner/xc5000",
 343 };
 344
 345 static void do_i2c_scan(char *name, struct i2c_client *c)
 346 {
 347         unsigned char buf;
 348         int i, rc;
 349
 350         for (i = 0; i < 128; i++) {
 351                 c->addr = i;
 352                 rc = i2c_master_recv(c, &buf, 0);
 353                 if (rc < 0)
 354                         continue;
 355                 pr_info("%s: i2c scan: found device @ 0x%x  [%s]\n",
 356                        name, i << 1, i2c_devs[i] ? i2c_devs[i] : "???");
 357         }
 358 }
 359
 360 /* init + register i2c adapter */
 361 int au0828_i2c_register(struct au0828_dev *dev)
 362 {
 363         dprintk(1, "%s()\n", __func__);
 364
 365         dev->i2c_adap = au0828_i2c_adap_template;
 366         dev->i2c_algo = au0828_i2c_algo_template;
 367         dev->i2c_client = au0828_i2c_client_template;
 368
 369         dev->i2c_adap.dev.parent = &dev->usbdev->dev;
 370
 371         strscpy(dev->i2c_adap.name, KBUILD_MODNAME,
 372                 sizeof(dev->i2c_adap.name));
 373
 374         dev->i2c_adap.algo = &dev->i2c_algo;
 375         dev->i2c_adap.algo_data = dev;
 376 #ifdef CONFIG_VIDEO_AU0828_V4L2
 377         i2c_set_adapdata(&dev->i2c_adap, &dev->v4l2_dev);
 378 #else
 379         i2c_set_adapdata(&dev->i2c_adap, dev);
 380 #endif
 381         i2c_add_adapter(&dev->i2c_adap);
 382
 383         dev->i2c_client.adapter = &dev->i2c_adap;
 384
 385         if (0 == dev->i2c_rc) {
 386                 pr_info("i2c bus registered\n");
 387                 if (i2c_scan)
 388                         do_i2c_scan(KBUILD_MODNAME, &dev->i2c_client);
 389         } else
 390                 pr_info("i2c bus register FAILED\n");
 391
 392         return dev->i2c_rc;
 393 }
 394
 395 int au0828_i2c_unregister(struct au0828_dev *dev)
 396 {
 397         i2c_del_adapter(&dev->i2c_adap);
 398         return 0;
 399 }
 400