err.no Git - linux-2.6/blob - 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()\n", __FUNCTION__);
  88         /* Deal with i2c probe functions with zero payload */
  89         if (msg->len == 0) {
  90                 cx_write(bus->reg_addr, msg->addr << 25);
  91                 cx_write(bus->reg_ctrl, bus->i2c_period | (1 << 2));
  92                 if (!i2c_wait_done(i2c_adap))
  93                         return -EIO;
  94                 if (!i2c_slave_did_ack(i2c_adap))
  95                         return -EIO;
  96
  97                 dprintk(1, "%s() returns 0\n", __FUNCTION__);
  98                 return 0;
  99         }
 100
 101
 102         /* dev, reg + first byte */
 103         addr = (msg->addr << 25) | msg->buf[0];
 104         wdata = msg->buf[0];
 105         ctrl = bus->i2c_period | (1 << 12) | (1 << 2);
 106
 107         if (msg->len > 1)
 108                 ctrl |= I2C_NOSTOP | I2C_EXTEND;
 109
 110         cx_write(bus->reg_addr, addr);
 111         cx_write(bus->reg_wdata, wdata);
 112         cx_write(bus->reg_ctrl, ctrl);
 113
 114         retval = i2c_wait_done(i2c_adap);
 115         if (retval < 0)
 116                 goto err;
 117         if (retval == 0)
 118                 goto eio;
 119         if (i2c_debug) {
 120                 printk(" <W %02x %02x", msg->addr << 1, msg->buf[0]);
 121                 if (!(ctrl & I2C_NOSTOP))
 122                         printk(" >\n");
 123         }
 124
 125         for (cnt = 1; cnt < msg->len; cnt++ ) {
 126                 /* following bytes */
 127                 wdata = msg->buf[cnt];
 128                 ctrl = bus->i2c_period | (1 << 12) | (1 << 2);
 129
 130                 if (cnt < msg->len-1 || !last)
 131                         ctrl |= I2C_NOSTOP | I2C_EXTEND;
 132
 133                 cx_write(bus->reg_addr, addr);
 134                 cx_write(bus->reg_wdata, wdata);
 135                 cx_write(bus->reg_ctrl, ctrl);
 136
 137                 retval = i2c_wait_done(i2c_adap);
 138                 if (retval < 0)
 139                         goto err;
 140                 if (retval == 0)
 141                         goto eio;
 142                 if (i2c_debug) {
 143                         printk(" %02x", msg->buf[cnt]);
 144                         if (!(ctrl & I2C_NOSTOP))
 145                                 printk(" >\n");
 146                 }
 147         }
 148         return msg->len;
 149
 150  eio:
 151         retval = -EIO;
 152  err:
 153         printk(" ERR: %d\n", retval);
 154         return retval;
 155 }
 156
 157 static int i2c_readbytes(struct i2c_adapter *i2c_adap,
 158                          const struct i2c_msg *msg, int last)
 159 {
 160         struct cx23885_i2c *bus = i2c_adap->algo_data;
 161         struct cx23885_dev *dev = bus->dev;
 162         u32 ctrl, cnt;
 163         int retval;
 164
 165         dprintk(1, "%s()\n", __FUNCTION__);
 166
 167         /* Deal with i2c probe functions with zero payload */
 168         if (msg->len == 0) {
 169                 cx_write(bus->reg_addr, msg->addr << 25);
 170                 cx_write(bus->reg_ctrl, bus->i2c_period | (1 << 2) | 1);
 171                 if (!i2c_wait_done(i2c_adap))
 172                         return -EIO;
 173                 if (!i2c_slave_did_ack(i2c_adap))
 174                         return -EIO;
 175
 176
 177                 dprintk(1, "%s() returns 0\n", __FUNCTION__);
 178                 return 0;
 179         }
 180
 181         for(cnt = 0; cnt < msg->len; cnt++) {
 182
 183                 ctrl = bus->i2c_period | (1 << 12) | (1 << 2) | 1;
 184
 185                 if (cnt < msg->len-1 || !last)
 186                         ctrl |= I2C_NOSTOP | I2C_EXTEND;
 187
 188                 cx_write(bus->reg_addr, msg->addr << 25);
 189                 cx_write(bus->reg_ctrl, ctrl);
 190
 191                 retval = i2c_wait_done(i2c_adap);
 192                 if (retval < 0)
 193                         goto err;
 194                 if (retval == 0)
 195                         goto eio;
 196                 msg->buf[cnt] = cx_read(bus->reg_rdata) & 0xff;
 197                 if (i2c_debug) {
 198                         if (!(ctrl & I2C_NOSTOP))
 199                                 printk(" <R %02x", (msg->addr << 1) +1);
 200                         printk(" =%02x", msg->buf[cnt]);
 201                         if (!(ctrl & I2C_NOSTOP))
 202                                 printk(" >\n");
 203                 }
 204         }
 205         return msg->len;
 206
 207  eio:
 208         retval = -EIO;
 209  err:
 210         printk(" ERR: %d\n", retval);
 211         return retval;
 212 }
 213
 214 static int i2c_xfer(struct i2c_adapter *i2c_adap,
 215                     struct i2c_msg *msgs, int num)
 216 {
 217         struct cx23885_i2c *bus = i2c_adap->algo_data;
 218         struct cx23885_dev *dev = bus->dev;
 219         int i, retval = 0;
 220
 221         dprintk(1, "%s(num = %d)\n", __FUNCTION__, num);
 222
 223         for (i = 0 ; i < num; i++) {
 224                 dprintk(1, "%s(num = %d) addr = 0x%02x  len = 0x%x\n",
 225                         __FUNCTION__, num, msgs[i].addr, msgs[i].len);
 226                 if (msgs[i].flags & I2C_M_RD) {
 227                         /* read */
 228                         retval = i2c_readbytes(i2c_adap, &msgs[i], i+1 == num);
 229                         if (retval < 0)
 230                                 goto err;
 231                 } else {
 232                         /* write */
 233                         retval = i2c_sendbytes(i2c_adap, &msgs[i], i+1 == num);
 234                         if (retval < 0)
 235                                 goto err;
 236                 }
 237         }
 238         return num;
 239
 240  err:
 241         return retval;
 242 }
 243
 244 static int attach_inform(struct i2c_client *client)
 245 {
 246         struct cx23885_dev *dev = i2c_get_adapdata(client->adapter);
 247
 248         dprintk(1, "%s i2c attach [addr=0x%x,client=%s]\n",
 249                 client->driver->driver.name, client->addr, client->name);
 250
 251         if (!client->driver->command)
 252                 return 0;
 253
 254         return 0;
 255 }
 256
 257 static int detach_inform(struct i2c_client *client)
 258 {
 259         struct cx23885_dev *dev = i2c_get_adapdata(client->adapter);
 260
 261         dprintk(1, "i2c detach [client=%s]\n", client->name);
 262
 263         return 0;
 264 }
 265
 266 void cx23885_call_i2c_clients(struct cx23885_i2c *bus,
 267                               unsigned int cmd, void *arg)
 268 {
 269         if (bus->i2c_rc != 0)
 270                 return;
 271
 272         i2c_clients_command(&bus->i2c_adap, cmd, arg);
 273 }
 274
 275 static int cx23885_algo_control(struct i2c_adapter *adap,
 276                                 unsigned int cmd, unsigned long arg)
 277 {
 278         return 0;
 279 }
 280
 281 static u32 cx23885_functionality(struct i2c_adapter *adap)
 282 {
 283         return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_I2C;
 284 }
 285
 286 static struct i2c_algorithm cx23885_i2c_algo_template = {
 287         .master_xfer    = i2c_xfer,
 288         .algo_control   = cx23885_algo_control,
 289         .functionality  = cx23885_functionality,
 290 };
 291
 292 /* ----------------------------------------------------------------------- */
 293
 294 static struct i2c_adapter cx23885_i2c_adap_template = {
 295         .name              = "cx23885",
 296         .owner             = THIS_MODULE,
 297         .id                = I2C_HW_B_CX23885,
 298         .algo              = &cx23885_i2c_algo_template,
 299         .client_register   = attach_inform,
 300         .client_unregister = detach_inform,
 301 };
 302
 303 static struct i2c_client cx23885_i2c_client_template = {
 304         .name   = "cx23885 internal",
 305 };
 306
 307 static char *i2c_devs[128] = {
 308         [ 0x1c >> 1 ] = "lgdt3303",
 309         [ 0x86 >> 1 ] = "tda9887",
 310         [ 0x32 >> 1 ] = "cx24227",
 311         [ 0x88 >> 1 ] = "cx25837",
 312         [ 0x84 >> 1 ] = "tda8295",
 313         [ 0xa0 >> 1 ] = "eeprom",
 314         [ 0xc0 >> 1 ] = "tuner/mt2131/tda8275",
 315         [ 0xc2 >> 1 ] = "tuner/mt2131/tda8275",
 316 };
 317
 318 static void do_i2c_scan(char *name, struct i2c_client *c)
 319 {
 320         unsigned char buf;
 321         int i, rc;
 322
 323         for (i = 0; i < 128; i++) {
 324                 c->addr = i;
 325                 rc = i2c_master_recv(c, &buf, 0);
 326                 if (rc < 0)
 327                         continue;
 328                 printk("%s: i2c scan: found device @ 0x%x  [%s]\n",
 329                        name, i << 1, i2c_devs[i] ? i2c_devs[i] : "???");
 330         }
 331 }
 332
 333 /* init + register i2c algo-bit adapter */
 334 int cx23885_i2c_register(struct cx23885_i2c *bus)
 335 {
 336         struct cx23885_dev *dev = bus->dev;
 337
 338         dprintk(1, "%s(bus = %d)\n", __FUNCTION__, bus->nr);
 339
 340         memcpy(&bus->i2c_adap, &cx23885_i2c_adap_template,
 341                sizeof(bus->i2c_adap));
 342         memcpy(&bus->i2c_algo, &cx23885_i2c_algo_template,
 343                sizeof(bus->i2c_algo));
 344         memcpy(&bus->i2c_client, &cx23885_i2c_client_template,
 345                sizeof(bus->i2c_client));
 346
 347         bus->i2c_adap.dev.parent = &dev->pci->dev;
 348
 349         strlcpy(bus->i2c_adap.name, bus->dev->name,
 350                 sizeof(bus->i2c_adap.name));
 351
 352         bus->i2c_algo.data = bus;
 353         bus->i2c_adap.algo_data = bus;
 354         i2c_add_adapter(&bus->i2c_adap);
 355
 356         bus->i2c_client.adapter = &bus->i2c_adap;
 357
 358         if (0 == bus->i2c_rc) {
 359                 printk("%s: i2c bus %d registered\n", dev->name, bus->nr);
 360                 if (i2c_scan)
 361                         do_i2c_scan(dev->name, &bus->i2c_client);
 362         } else
 363                 printk("%s: i2c bus %d register FAILED\n", dev->name, bus->nr);
 364
 365         return bus->i2c_rc;
 366 }
 367
 368 int cx23885_i2c_unregister(struct cx23885_i2c *bus)
 369 {
 370         i2c_del_adapter(&bus->i2c_adap);
 371         return 0;
 372 }
 373
 374 /* ----------------------------------------------------------------------- */
 375
 376 EXPORT_SYMBOL(cx23885_call_i2c_clients);
 377
 378 /*
 379  * Local variables:
 380  * c-basic-offset: 8
 381  * End:
 382  */