drivers/media/video/cx23885/cx23885-i2c.c

   1 /*
   2  *  Driver for the Conexant CX23885 PCIe bridge
   3  *
   4  *  Copyright (c) 2006 Steven Toth <stoth@hauppauge.com>
   5  *
   6  *  This program is free software; you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation; either version 2 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  This program is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *
  15  *  GNU General Public License for more details.
  16  *
  17  *  You should have received a copy of the GNU General Public License
  18  *  along with this program; if not, write to the Free Software
  19  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20  */
  21
  22 #include <linux/module.h>
  23 #include <linux/moduleparam.h>
  24 #include <linux/init.h>
  25 #include <linux/delay.h>
  26 #include <asm/io.h>
  27
  28 #include "cx23885.h"
  29
  30 #include <media/v4l2-common.h>
  31
  32 static unsigned int i2c_debug = 0;
  33 module_param(i2c_debug, int, 0644);
  34 MODULE_PARM_DESC(i2c_debug, "enable debug messages [i2c]");
  35
  36 static unsigned int i2c_scan = 0;
  37 module_param(i2c_scan, int, 0444);
  38 MODULE_PARM_DESC(i2c_scan, "scan i2c bus at insmod time");
  39
  40 #define dprintk(level,fmt, arg...)      if (i2c_debug >= level) \
  41         printk(KERN_DEBUG "%s: " fmt, dev->name , ## arg)
  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 cx23885_i2c *bus = i2c_adap->algo_data;
  52         struct cx23885_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 cx23885_i2c *bus = i2c_adap->algo_data;
  59         struct cx23885_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 last)
  81 {
  82         struct cx23885_i2c *bus = i2c_adap->algo_data;
  83         struct cx23885_dev *dev = bus->dev;
  84         u32 wdata, addr, ctrl;
  85         int retval, cnt;
  86
  87         dprintk(1, "%s(msg->len=%d, last=%d)\n", __FUNCTION__, msg->len, last);
  88
  89         /* Deal with i2c probe functions with zero payload */
  90         if (msg->len == 0) {
  91                 cx_write(bus->reg_addr, msg->addr << 25);
  92                 cx_write(bus->reg_ctrl, bus->i2c_period | (1 << 2));
  93                 if (!i2c_wait_done(i2c_adap))
  94                         return -EIO;
  95                 if (!i2c_slave_did_ack(i2c_adap))
  96                         return -EIO;
  97
  98                 dprintk(1, "%s() returns 0\n", __FUNCTION__);
  99                 return 0;
 100         }
 101
 102
 103         /* dev, reg + first byte */
 104         addr = (msg->addr << 25) | msg->buf[0];
 105         wdata = msg->buf[0];
 106         ctrl = bus->i2c_period | (1 << 12) | (1 << 2);
 107
 108         if (msg->len > 1)
 109                 ctrl |= I2C_NOSTOP | I2C_EXTEND;
 110
 111         cx_write(bus->reg_addr, addr);
 112         cx_write(bus->reg_wdata, wdata);
 113         cx_write(bus->reg_ctrl, ctrl);
 114
 115         retval = i2c_wait_done(i2c_adap);
 116         if (retval < 0)
 117                 goto err;
 118         if (retval == 0)
 119                 goto eio;
 120         if (i2c_debug) {
 121                 printk(" <W %02x %02x", msg->addr << 1, msg->buf[0]);
 122                 if (!(ctrl & I2C_NOSTOP))
 123                         printk(" >\n");
 124         }
 125
 126         for (cnt = 1; cnt < msg->len; cnt++ ) {
 127                 /* following bytes */
 128                 wdata = msg->buf[cnt];
 129                 ctrl = bus->i2c_period | (1 << 12) | (1 << 2);
 130
 131                 if (cnt < msg->len - 1)
 132                         ctrl |= I2C_NOSTOP | I2C_EXTEND;
 133
 134                 cx_write(bus->reg_addr, addr);
 135                 cx_write(bus->reg_wdata, wdata);
 136                 cx_write(bus->reg_ctrl, ctrl);
 137
 138                 retval = i2c_wait_done(i2c_adap);
 139                 if (retval < 0)
 140                         goto err;
 141                 if (retval == 0)
 142                         goto eio;
 143                 if (i2c_debug) {
 144                         printk(" %02x", msg->buf[cnt]);
 145                         if (!(ctrl & I2C_NOSTOP))
 146                                 printk(" >\n");
 147                 }
 148         }
 149         return msg->len;
 150
 151  eio:
 152         retval = -EIO;
 153  err:
 154         printk(" ERR: %d\n", retval);
 155         return retval;
 156 }
 157
 158 static int i2c_readbytes(struct i2c_adapter *i2c_adap,
 159                          const struct i2c_msg *msg, int last)
 160 {
 161         struct cx23885_i2c *bus = i2c_adap->algo_data;
 162         struct cx23885_dev *dev = bus->dev;
 163         u32 ctrl, cnt;
 164         int retval;
 165
 166         dprintk(1, "%s(msg->len=%d, last=%d)\n", __FUNCTION__, msg->len, last);
 167
 168         /* Deal with i2c probe functions with zero payload */
 169         if (msg->len == 0) {
 170                 cx_write(bus->reg_addr, msg->addr << 25);
 171                 cx_write(bus->reg_ctrl, bus->i2c_period | (1 << 2) | 1);
 172                 if (!i2c_wait_done(i2c_adap))
 173                         return -EIO;
 174                 if (!i2c_slave_did_ack(i2c_adap))
 175                         return -EIO;
 176
 177
 178                 dprintk(1, "%s() returns 0\n", __FUNCTION__);
 179                 return 0;
 180         }
 181
 182         if (i2c_debug)
 183                 printk(" <R %02x", (msg->addr << 1) + 1);
 184
 185         for(cnt = 0; cnt < msg->len; cnt++) {
 186
 187                 ctrl = bus->i2c_period | (1 << 12) | (1 << 2) | 1;
 188
 189                 if (cnt < msg->len - 1)
 190                         ctrl |= I2C_NOSTOP | I2C_EXTEND;
 191
 192                 cx_write(bus->reg_addr, msg->addr << 25);
 193                 cx_write(bus->reg_ctrl, ctrl);
 194
 195                 retval = i2c_wait_done(i2c_adap);
 196                 if (retval < 0)
 197                         goto err;
 198                 if (retval == 0)
 199                         goto eio;
 200                 msg->buf[cnt] = cx_read(bus->reg_rdata) & 0xff;
 201                 if (i2c_debug) {
 202                         printk(" %02x", msg->buf[cnt]);
 203                         if (!(ctrl & I2C_NOSTOP))
 204                                 printk(" >\n");
 205                 }
 206         }
 207         return msg->len;
 208
 209  eio:
 210         retval = -EIO;
 211  err:
 212         printk(" ERR: %d\n", retval);
 213         return retval;
 214 }
 215
 216 static int i2c_xfer(struct i2c_adapter *i2c_adap,
 217                     struct i2c_msg *msgs, int num)
 218 {
 219         struct cx23885_i2c *bus = i2c_adap->algo_data;
 220         struct cx23885_dev *dev = bus->dev;
 221         int i, retval = 0;
 222
 223         dprintk(1, "%s(num = %d)\n", __FUNCTION__, num);
 224
 225         for (i = 0 ; i < num; i++) {
 226                 dprintk(1, "%s(num = %d) addr = 0x%02x  len = 0x%x\n",
 227                         __FUNCTION__, num, msgs[i].addr, msgs[i].len);
 228                 if (msgs[i].flags & I2C_M_RD) {
 229                         /* read */
 230                         retval = i2c_readbytes(i2c_adap, &msgs[i], i+1 == num);
 231                         if (retval < 0)
 232                                 goto err;
 233                 } else {
 234                         /* write */
 235                         retval = i2c_sendbytes(i2c_adap, &msgs[i], i+1 == num);
 236                         if (retval < 0)
 237                                 goto err;
 238                 }
 239         }
 240         return num;
 241
 242  err:
 243         return retval;
 244 }
 245
 246 static int attach_inform(struct i2c_client *client)
 247 {
 248         struct cx23885_dev *dev = i2c_get_adapdata(client->adapter);
 249
 250         dprintk(1, "%s i2c attach [addr=0x%x,client=%s]\n",
 251                 client->driver->driver.name, client->addr, client->name);
 252
 253         if (!client->driver->command)
 254                 return 0;
 255
 256         return 0;
 257 }
 258
 259 static int detach_inform(struct i2c_client *client)
 260 {
 261         struct cx23885_dev *dev = i2c_get_adapdata(client->adapter);
 262
 263         dprintk(1, "i2c detach [client=%s]\n", client->name);
 264
 265         return 0;
 266 }
 267
 268 void cx23885_call_i2c_clients(struct cx23885_i2c *bus,
 269                               unsigned int cmd, void *arg)
 270 {
 271         if (bus->i2c_rc != 0)
 272                 return;
 273
 274         i2c_clients_command(&bus->i2c_adap, cmd, arg);
 275 }
 276
 277 static u32 cx23885_functionality(struct i2c_adapter *adap)
 278 {
 279         return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_I2C;
 280 }
 281
 282 static struct i2c_algorithm cx23885_i2c_algo_template = {
 283         .master_xfer    = i2c_xfer,
 284         .functionality  = cx23885_functionality,
 285 };
 286
 287 /* ----------------------------------------------------------------------- */
 288
 289 static struct i2c_adapter cx23885_i2c_adap_template = {
 290         .name              = "cx23885",
 291         .owner             = THIS_MODULE,
 292         .id                = I2C_HW_B_CX23885,
 293         .algo              = &cx23885_i2c_algo_template,
 294         .client_register   = attach_inform,
 295         .client_unregister = detach_inform,
 296 };
 297
 298 static struct i2c_client cx23885_i2c_client_template = {
 299         .name   = "cx23885 internal",
 300 };
 301
 302 static char *i2c_devs[128] = {
 303         [ 0x1c >> 1 ] = "lgdt3303",
 304         [ 0x86 >> 1 ] = "tda9887",
 305         [ 0x32 >> 1 ] = "cx24227",
 306         [ 0x88 >> 1 ] = "cx25837",
 307         [ 0x84 >> 1 ] = "tda8295",
 308         [ 0xa0 >> 1 ] = "eeprom",
 309         [ 0xc0 >> 1 ] = "tuner/mt2131/tda8275",
 310         [ 0xc2 >> 1 ] = "tuner/mt2131/tda8275",
 311 };
 312
 313 static void do_i2c_scan(char *name, struct i2c_client *c)
 314 {
 315         unsigned char buf;
 316         int i, rc;
 317
 318         for (i = 0; i < 128; i++) {
 319                 c->addr = i;
 320                 rc = i2c_master_recv(c, &buf, 0);
 321                 if (rc < 0)
 322                         continue;
 323                 printk("%s: i2c scan: found device @ 0x%x  [%s]\n",
 324                        name, i << 1, i2c_devs[i] ? i2c_devs[i] : "???");
 325         }
 326 }
 327
 328 /* init + register i2c algo-bit adapter */
 329 int cx23885_i2c_register(struct cx23885_i2c *bus)
 330 {
 331         struct cx23885_dev *dev = bus->dev;
 332
 333         dprintk(1, "%s(bus = %d)\n", __FUNCTION__, bus->nr);
 334
 335         memcpy(&bus->i2c_adap, &cx23885_i2c_adap_template,
 336                sizeof(bus->i2c_adap));
 337         memcpy(&bus->i2c_algo, &cx23885_i2c_algo_template,
 338                sizeof(bus->i2c_algo));
 339         memcpy(&bus->i2c_client, &cx23885_i2c_client_template,
 340                sizeof(bus->i2c_client));
 341
 342         bus->i2c_adap.dev.parent = &dev->pci->dev;
 343
 344         strlcpy(bus->i2c_adap.name, bus->dev->name,
 345                 sizeof(bus->i2c_adap.name));
 346
 347         bus->i2c_algo.data = bus;
 348         bus->i2c_adap.algo_data = bus;
 349         i2c_add_adapter(&bus->i2c_adap);
 350
 351         bus->i2c_client.adapter = &bus->i2c_adap;
 352
 353         if (0 == bus->i2c_rc) {
 354                 printk("%s: i2c bus %d registered\n", dev->name, bus->nr);
 355                 if (i2c_scan)
 356                         do_i2c_scan(dev->name, &bus->i2c_client);
 357         } else
 358                 printk("%s: i2c bus %d register FAILED\n", dev->name, bus->nr);
 359
 360         return bus->i2c_rc;
 361 }
 362
 363 int cx23885_i2c_unregister(struct cx23885_i2c *bus)
 364 {
 365         i2c_del_adapter(&bus->i2c_adap);
 366         return 0;
 367 }
 368
 369 /* ----------------------------------------------------------------------- */
 370
 371 /*
 372  * Local variables:
 373  * c-basic-offset: 8
 374  * End:
 375  */