LXR linux/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
  19static int i2c_scan;
  20module_param(i2c_scan, int, 0444);
  21MODULE_PARM_DESC(i2c_scan, "scan i2c bus at insmod time");
  22
  23#define I2C_WAIT_DELAY 25
  24#define I2C_WAIT_RETRY 1000
  25
  26static 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
  33static 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
  40static 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
  56static 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
  63static 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
  79static 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
  86static 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
 102static 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
 109static 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 */
 126static 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 */
 216static 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
 282static 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
 313err:
 314        return retval;
 315}
 316
 317static u32 au0828_functionality(struct i2c_adapter *adap)
 318{
 319        return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_I2C;
 320}
 321
 322static const struct i2c_algorithm au0828_i2c_algo_template = {
 323        .master_xfer    = i2c_xfer,
 324        .functionality  = au0828_functionality,
 325};
 326
 327/* ----------------------------------------------------------------------- */
 328
 329static const struct i2c_adapter au0828_i2c_adap_template = {
 330        .name              = KBUILD_MODNAME,
 331        .owner             = THIS_MODULE,
 332        .algo              = &au0828_i2c_algo_template,
 333};
 334
 335static const struct i2c_client au0828_i2c_client_template = {
 336        .name   = "au0828 internal",
 337};
 338
 339static char *i2c_devs[128] = {
 340        [0x8e >> 1] = "au8522",
 341        [0xa0 >> 1] = "eeprom",
 342        [0xc2 >> 1] = "tuner/xc5000",
 343};
 344
 345static 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 */
 361int 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
 395int au0828_i2c_unregister(struct au0828_dev *dev)
 396{
 397        i2c_del_adapter(&dev->i2c_adap);
 398        return 0;
 399}
 400
 401