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                 //printk("addr = 0x%08x  wdata = 0x%08x  ctrl = 0x%08x\n", addr, wdata, ctrl);
 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()\n", __FUNCTION__);
 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         for(cnt = 0; cnt < msg->len; cnt++) {
 183
 184                 ctrl = bus->i2c_period | (1 << 12) | (1 << 2) | 1;
 185
 186                 if (cnt < msg->len-1 || !last)
 187                         ctrl |= I2C_NOSTOP | I2C_EXTEND;
 188
 189                 cx_write(bus->reg_addr, msg->addr << 25);
 190                 cx_write(bus->reg_ctrl, ctrl);
 191
 192                 retval = i2c_wait_done(i2c_adap);
 193                 if (retval < 0)
 194                         goto err;
 195                 if (retval == 0)
 196                         goto eio;
 197                 msg->buf[cnt] = cx_read(bus->reg_rdata) & 0xff;
 198                 if (i2c_debug) {
 199                         if (!(ctrl & I2C_NOSTOP))
 200                                 printk(" <R %02x", (msg->addr << 1) +1);
 201                         printk(" =%02x", msg->buf[cnt]);
 202                         if (!(ctrl & I2C_NOSTOP))
 203                                 printk(" >\n");
 204                 }
 205         }
 206         return msg->len;
 207
 208  eio:
 209         retval = -EIO;
 210  err:
 211         printk(" ERR: %d\n", retval);
 212         return retval;
 213 }
 214
 215 static int i2c_xfer(struct i2c_adapter *i2c_adap,
 216                     struct i2c_msg *msgs, int num)
 217 {
 218         struct cx23885_i2c *bus = i2c_adap->algo_data;
 219         struct cx23885_dev *dev = bus->dev;
 220         int i, retval = 0;
 221
 222         dprintk(1, "%s(num = %d)\n", __FUNCTION__, num);
 223
 224         for (i = 0 ; i < num; i++) {
 225                 dprintk(1, "%s(num = %d) addr = 0x%02x  len = 0x%x\n",
 226                         __FUNCTION__, num, msgs[i].addr, msgs[i].len);
 227                 if (msgs[i].flags & I2C_M_RD) {
 228                         /* read */
 229                         retval = i2c_readbytes(i2c_adap, &msgs[i], i+1 == num);
 230                         if (retval < 0)
 231                                 goto err;
 232                 } else {
 233                         /* write */
 234                         retval = i2c_sendbytes(i2c_adap, &msgs[i], i+1 == num);
 235                         if (retval < 0)
 236                                 goto err;
 237                 }
 238         }
 239         return num;
 240
 241  err:
 242         return retval;
 243 }
 244
 245 static int attach_inform(struct i2c_client *client)
 246 {
 247         struct cx23885_dev *dev = i2c_get_adapdata(client->adapter);
 248
 249         dprintk(1, "%s i2c attach [addr=0x%x,client=%s]\n",
 250                 client->driver->driver.name, client->addr, client->name);
 251
 252         if (!client->driver->command)
 253                 return 0;
 254
 255         return 0;
 256 }
 257
 258 static int detach_inform(struct i2c_client *client)
 259 {
 260         struct cx23885_dev *dev = i2c_get_adapdata(client->adapter);
 261
 262         dprintk(1, "i2c detach [client=%s]\n", client->name);
 263
 264         return 0;
 265 }
 266
 267 void cx23885_call_i2c_clients(struct cx23885_i2c *bus,
 268                               unsigned int cmd, void *arg)
 269 {
 270         if (bus->i2c_rc != 0)
 271                 return;
 272
 273         i2c_clients_command(&bus->i2c_adap, cmd, arg);
 274 }
 275
 276 static int cx23885_algo_control(struct i2c_adapter *adap,
 277                                 unsigned int cmd, unsigned long arg)
 278 {
 279         return 0;
 280 }
 281
 282 static u32 cx23885_functionality(struct i2c_adapter *adap)
 283 {
 284         return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_I2C;
 285 }
 286
 287 static struct i2c_algorithm cx23885_i2c_algo_template = {
 288         .master_xfer    = i2c_xfer,
 289         .algo_control   = cx23885_algo_control,
 290         .functionality  = cx23885_functionality,
 291 };
 292
 293 /* ----------------------------------------------------------------------- */
 294
 295 static struct i2c_adapter cx23885_i2c_adap_template = {
 296         .name              = "cx23885",
 297         .owner             = THIS_MODULE,
 298         .id                = I2C_HW_B_CX23885,
 299         .algo              = &cx23885_i2c_algo_template,
 300 //      .class             = I2C_CLASS_TV_ANALOG,
 301         .client_register   = attach_inform,
 302         .client_unregister = detach_inform,
 303 };
 304
 305 static struct i2c_client cx23885_i2c_client_template = {
 306         .name   = "cx23885 internal",
 307 };
 308
 309 static char *i2c_devs[128] = {
 310         [ 0x32 >> 1 ] = "cx24227",
 311         [ 0x88 >> 1 ] = "cx25837",
 312         [ 0x84 >> 1 ] = "tda8295",
 313         [ 0xa0 >> 1 ] = "eeprom",
 314         [ 0xc0 >> 1 ] = "mt2131/tda8275",
 315         [ 0xc2 >> 1 ] = "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         bus->i2c_algo.data = bus;
 352         bus->i2c_adap.algo_data = bus;
 353         i2c_add_adapter(&bus->i2c_adap);
 354
 355         bus->i2c_client.adapter = &bus->i2c_adap;
 356
 357         if (0 == bus->i2c_rc) {
 358                 printk("%s: i2c bus %d registered\n", dev->name, bus->nr);
 359                 if (i2c_scan)
 360                         do_i2c_scan(dev->name, &bus->i2c_client);
 361         } else
 362                 printk("%s: i2c bus %d register FAILED\n", dev->name, bus->nr);
 363
 364         return bus->i2c_rc;
 365 }
 366
 367 int cx23885_i2c_unregister(struct cx23885_i2c *bus)
 368 {
 369         i2c_del_adapter(&bus->i2c_adap);
 370         return 0;
 371 }
 372
 373 /* ----------------------------------------------------------------------- */
 374
 375 EXPORT_SYMBOL(cx23885_call_i2c_clients);
 376
 377 /*
 378  * Local variables:
 379  * c-basic-offset: 8
 380  * End:
 381  */