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_read_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_READ_ACK ? 0 : 1;
  31 }
  32
  33 static int i2c_wait_read_ack(struct i2c_adapter *i2c_adap)
  34 {
  35         int count;
  36
  37         for (count = 0; count < I2C_WAIT_RETRY; count++) {
  38                 if (!i2c_slave_did_read_ack(i2c_adap))
  39                         break;
  40                 udelay(I2C_WAIT_DELAY);
  41         }
  42
  43         if (I2C_WAIT_RETRY == count)
  44                 return 0;
  45
  46         return 1;
  47 }
  48
  49 static inline int i2c_is_read_busy(struct i2c_adapter *i2c_adap)
  50 {
  51         struct au0828_dev *dev = i2c_adap->algo_data;
  52         return au0828_read(dev, AU0828_I2C_STATUS_201) &
  53                 AU0828_I2C_STATUS_READ_DONE ? 0 : 1;
  54 }
  55
  56 static int i2c_wait_read_done(struct i2c_adapter *i2c_adap)
  57 {
  58         int count;
  59
  60         for (count = 0; count < I2C_WAIT_RETRY; count++) {
  61                 if (!i2c_is_read_busy(i2c_adap))
  62                         break;
  63                 udelay(I2C_WAIT_DELAY);
  64         }
  65
  66         if (I2C_WAIT_RETRY == count)
  67                 return 0;
  68
  69         return 1;
  70 }
  71
  72 static inline int i2c_is_write_done(struct i2c_adapter *i2c_adap)
  73 {
  74         struct au0828_dev *dev = i2c_adap->algo_data;
  75         return au0828_read(dev, AU0828_I2C_STATUS_201) &
  76                 AU0828_I2C_STATUS_WRITE_DONE ? 1 : 0;
  77 }
  78
  79 static int i2c_wait_write_done(struct i2c_adapter *i2c_adap)
  80 {
  81         int count;
  82
  83         for (count = 0; count < I2C_WAIT_RETRY; count++) {
  84                 if (i2c_is_write_done(i2c_adap))
  85                         break;
  86                 udelay(I2C_WAIT_DELAY);
  87         }
  88
  89         if (I2C_WAIT_RETRY == count)
  90                 return 0;
  91
  92         return 1;
  93 }
  94
  95 static inline int i2c_is_busy(struct i2c_adapter *i2c_adap)
  96 {
  97         struct au0828_dev *dev = i2c_adap->algo_data;
  98         return au0828_read(dev, AU0828_I2C_STATUS_201) &
  99                 AU0828_I2C_STATUS_BUSY ? 1 : 0;
 100 }
 101
 102 static int i2c_wait_done(struct i2c_adapter *i2c_adap)
 103 {
 104         int count;
 105
 106         for (count = 0; count < I2C_WAIT_RETRY; count++) {
 107                 if (!i2c_is_busy(i2c_adap))
 108                         break;
 109                 udelay(I2C_WAIT_DELAY);
 110         }
 111
 112         if (I2C_WAIT_RETRY == count)
 113                 return 0;
 114
 115         return 1;
 116 }
 117
 118 /* FIXME: Implement join handling correctly */
 119 static int i2c_sendbytes(struct i2c_adapter *i2c_adap,
 120         const struct i2c_msg *msg, int joined_rlen)
 121 {
 122         int i, strobe = 0;
 123         struct au0828_dev *dev = i2c_adap->algo_data;
 124         u8 i2c_speed = dev->board.i2c_clk_divider;
 125
 126         dprintk(4, "%s()\n", __func__);
 127
 128         au0828_write(dev, AU0828_I2C_MULTIBYTE_MODE_2FF, 0x01);
 129
 130         if (((dev->board.tuner_type == TUNER_XC5000) ||
 131              (dev->board.tuner_type == TUNER_XC5000C)) &&
 132             (dev->board.tuner_addr == msg->addr)) {
 133                 /*
 134                  * Due to I2C clock stretch, we need to use a lower speed
 135                  * on xc5000 for commands. However, firmware transfer can
 136                  * speed up to 400 KHz.
 137                  */
 138                 if (msg->len == 64)
 139                         i2c_speed = AU0828_I2C_CLK_250KHZ;
 140                 else
 141                         i2c_speed = AU0828_I2C_CLK_20KHZ;
 142         }
 143         /* Set the I2C clock */
 144         au0828_write(dev, AU0828_I2C_CLK_DIVIDER_202, i2c_speed);
 145
 146         /* Hardware needs 8 bit addresses */
 147         au0828_write(dev, AU0828_I2C_DEST_ADDR_203, msg->addr << 1);
 148
 149         dprintk(4, "SEND: %02x\n", msg->addr);
 150
 151         /* Deal with i2c_scan */
 152         if (msg->len == 0) {
 153                 /* The analog tuner detection code makes use of the SMBUS_QUICK
 154                    message (which involves a zero length i2c write).  To avoid
 155                    checking the status register when we didn't strobe out any
 156                    actual bytes to the bus, just do a read check.  This is
 157                    consistent with how I saw i2c device checking done in the
 158                    USB trace of the Windows driver */
 159                 au0828_write(dev, AU0828_I2C_TRIGGER_200,
 160                              AU0828_I2C_TRIGGER_READ);
 161
 162                 if (!i2c_wait_done(i2c_adap))
 163                         return -EIO;
 164
 165                 if (i2c_wait_read_ack(i2c_adap))
 166                         return -EIO;
 167
 168                 return 0;
 169         }
 170
 171         for (i = 0; i < msg->len;) {
 172
 173                 dprintk(4, " %02x\n", msg->buf[i]);
 174
 175                 au0828_write(dev, AU0828_I2C_WRITE_FIFO_205, msg->buf[i]);
 176
 177                 strobe++;
 178                 i++;
 179
 180                 if ((strobe >= 4) || (i >= msg->len)) {
 181
 182                         /* Strobe the byte into the bus */
 183                         if (i < msg->len)
 184                                 au0828_write(dev, AU0828_I2C_TRIGGER_200,
 185                                              AU0828_I2C_TRIGGER_WRITE |
 186                                              AU0828_I2C_TRIGGER_HOLD);
 187                         else
 188                                 au0828_write(dev, AU0828_I2C_TRIGGER_200,
 189                                              AU0828_I2C_TRIGGER_WRITE);
 190
 191                         /* Reset strobe trigger */
 192                         strobe = 0;
 193
 194                         if (!i2c_wait_write_done(i2c_adap))
 195                                 return -EIO;
 196
 197                 }
 198
 199         }
 200         if (!i2c_wait_done(i2c_adap))
 201                 return -EIO;
 202
 203         dprintk(4, "\n");
 204
 205         return msg->len;
 206 }
 207
 208 /* FIXME: Implement join handling correctly */
 209 static int i2c_readbytes(struct i2c_adapter *i2c_adap,
 210         const struct i2c_msg *msg, int joined)
 211 {
 212         struct au0828_dev *dev = i2c_adap->algo_data;
 213         u8 i2c_speed = dev->board.i2c_clk_divider;
 214         int i;
 215
 216         dprintk(4, "%s()\n", __func__);
 217
 218         au0828_write(dev, AU0828_I2C_MULTIBYTE_MODE_2FF, 0x01);
 219
 220         /*
 221          * Due to xc5000c clock stretch, we cannot use full speed at
 222          * readings from xc5000, as otherwise they'll fail.
 223          */
 224         if (((dev->board.tuner_type == TUNER_XC5000) ||
 225              (dev->board.tuner_type == TUNER_XC5000C)) &&
 226             (dev->board.tuner_addr == msg->addr))
 227                 i2c_speed = AU0828_I2C_CLK_20KHZ;
 228
 229         /* Set the I2C clock */
 230         au0828_write(dev, AU0828_I2C_CLK_DIVIDER_202, i2c_speed);
 231
 232         /* Hardware needs 8 bit addresses */
 233         au0828_write(dev, AU0828_I2C_DEST_ADDR_203, msg->addr << 1);
 234
 235         dprintk(4, " RECV:\n");
 236
 237         /* Deal with i2c_scan */
 238         if (msg->len == 0) {
 239                 au0828_write(dev, AU0828_I2C_TRIGGER_200,
 240                              AU0828_I2C_TRIGGER_READ);
 241
 242                 if (i2c_wait_read_ack(i2c_adap))
 243                         return -EIO;
 244                 return 0;
 245         }
 246
 247         for (i = 0; i < msg->len;) {
 248
 249                 i++;
 250
 251                 if (i < msg->len)
 252                         au0828_write(dev, AU0828_I2C_TRIGGER_200,
 253                                      AU0828_I2C_TRIGGER_READ |
 254                                      AU0828_I2C_TRIGGER_HOLD);
 255                 else
 256                         au0828_write(dev, AU0828_I2C_TRIGGER_200,
 257                                      AU0828_I2C_TRIGGER_READ);
 258
 259                 if (!i2c_wait_read_done(i2c_adap))
 260                         return -EIO;
 261
 262                 msg->buf[i-1] = au0828_read(dev, AU0828_I2C_READ_FIFO_209) &
 263                         0xff;
 264
 265                 dprintk(4, " %02x\n", msg->buf[i-1]);
 266         }
 267         if (!i2c_wait_done(i2c_adap))
 268                 return -EIO;
 269
 270         dprintk(4, "\n");
 271
 272         return msg->len;
 273 }
 274
 275 static int i2c_xfer(struct i2c_adapter *i2c_adap,
 276                     struct i2c_msg *msgs, int num)
 277 {
 278         int i, retval = 0;
 279
 280         dprintk(4, "%s(num = %d)\n", __func__, num);
 281
 282         for (i = 0; i < num; i++) {
 283                 dprintk(4, "%s(num = %d) addr = 0x%02x  len = 0x%x\n",
 284                         __func__, num, msgs[i].addr, msgs[i].len);
 285                 if (msgs[i].flags & I2C_M_RD) {
 286                         /* read */
 287                         retval = i2c_readbytes(i2c_adap, &msgs[i], 0);
 288                 } else if (i + 1 < num && (msgs[i + 1].flags & I2C_M_RD) &&
 289                            msgs[i].addr == msgs[i + 1].addr) {
 290                         /* write then read from same address */
 291                         retval = i2c_sendbytes(i2c_adap, &msgs[i],
 292                                                msgs[i + 1].len);
 293                         if (retval < 0)
 294                                 goto err;
 295                         i++;
 296                         retval = i2c_readbytes(i2c_adap, &msgs[i], 1);
 297                 } else {
 298                         /* write */
 299                         retval = i2c_sendbytes(i2c_adap, &msgs[i], 0);
 300                 }
 301                 if (retval < 0)
 302                         goto err;
 303         }
 304         return num;
 305
 306 err:
 307         return retval;
 308 }
 309
 310 static u32 au0828_functionality(struct i2c_adapter *adap)
 311 {
 312         return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_I2C;
 313 }
 314
 315 static const struct i2c_algorithm au0828_i2c_algo_template = {
 316         .master_xfer    = i2c_xfer,
 317         .functionality  = au0828_functionality,
 318 };
 319
 320 /* ----------------------------------------------------------------------- */
 321
 322 static const struct i2c_adapter au0828_i2c_adap_template = {
 323         .name              = KBUILD_MODNAME,
 324         .owner             = THIS_MODULE,
 325         .algo              = &au0828_i2c_algo_template,
 326 };
 327
 328 static const struct i2c_client au0828_i2c_client_template = {
 329         .name   = "au0828 internal",
 330 };
 331
 332 static char *i2c_devs[128] = {
 333         [0x8e >> 1] = "au8522",
 334         [0xa0 >> 1] = "eeprom",
 335         [0xc2 >> 1] = "tuner/xc5000",
 336 };
 337
 338 static void do_i2c_scan(char *name, struct i2c_client *c)
 339 {
 340         unsigned char buf;
 341         int i, rc;
 342
 343         for (i = 0; i < 128; i++) {
 344                 c->addr = i;
 345                 rc = i2c_master_recv(c, &buf, 0);
 346                 if (rc < 0)
 347                         continue;
 348                 pr_info("%s: i2c scan: found device @ 0x%x  [%s]\n",
 349                        name, i << 1, i2c_devs[i] ? i2c_devs[i] : "???");
 350         }
 351 }
 352
 353 /* init + register i2c adapter */
 354 int au0828_i2c_register(struct au0828_dev *dev)
 355 {
 356         dprintk(1, "%s()\n", __func__);
 357
 358         dev->i2c_adap = au0828_i2c_adap_template;
 359         dev->i2c_algo = au0828_i2c_algo_template;
 360         dev->i2c_client = au0828_i2c_client_template;
 361
 362         dev->i2c_adap.dev.parent = &dev->usbdev->dev;
 363
 364         strscpy(dev->i2c_adap.name, KBUILD_MODNAME,
 365                 sizeof(dev->i2c_adap.name));
 366
 367         dev->i2c_adap.algo = &dev->i2c_algo;
 368         dev->i2c_adap.algo_data = dev;
 369 #ifdef CONFIG_VIDEO_AU0828_V4L2
 370         i2c_set_adapdata(&dev->i2c_adap, &dev->v4l2_dev);
 371 #else
 372         i2c_set_adapdata(&dev->i2c_adap, dev);
 373 #endif
 374         i2c_add_adapter(&dev->i2c_adap);
 375
 376         dev->i2c_client.adapter = &dev->i2c_adap;
 377
 378         if (0 == dev->i2c_rc) {
 379                 pr_info("i2c bus registered\n");
 380                 if (i2c_scan)
 381                         do_i2c_scan(KBUILD_MODNAME, &dev->i2c_client);
 382         } else
 383                 pr_info("i2c bus register FAILED\n");
 384
 385         return dev->i2c_rc;
 386 }
 387
 388 int au0828_i2c_unregister(struct au0828_dev *dev)
 389 {
 390         i2c_del_adapter(&dev->i2c_adap);
 391         return 0;
 392 }
 393