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

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  Driver for the Conexant CX23885 PCIe bridge
   4  *
   5  *  Copyright (c) 2006 Steven Toth <stoth@linuxtv.org>
   6  */
   7
   8 #include "cx23885.h"
   9
  10 #include <linux/module.h>
  11 #include <linux/init.h>
  12 #include <linux/delay.h>
  13 #include <asm/io.h>
  14
  15 #include <media/v4l2-common.h>
  16
  17 static unsigned int i2c_debug;
  18 module_param(i2c_debug, int, 0644);
  19 MODULE_PARM_DESC(i2c_debug, "enable debug messages [i2c]");
  20
  21 static unsigned int i2c_scan;
  22 module_param(i2c_scan, int, 0444);
  23 MODULE_PARM_DESC(i2c_scan, "scan i2c bus at insmod time");
  24
  25 #define dprintk(level, fmt, arg...)\
  26         do { if (i2c_debug >= level)\
  27                 printk(KERN_DEBUG pr_fmt("%s: i2c:" fmt), \
  28                         __func__, ##arg); \
  29         } while (0)
  30
  31 #define I2C_WAIT_DELAY 32
  32 #define I2C_WAIT_RETRY 64
  33
  34 #define I2C_EXTEND  (1 << 3)
  35 #define I2C_NOSTOP  (1 << 4)
  36
  37 static inline int i2c_slave_did_ack(struct i2c_adapter *i2c_adap)
  38 {
  39         struct cx23885_i2c *bus = i2c_adap->algo_data;
  40         struct cx23885_dev *dev = bus->dev;
  41         return cx_read(bus->reg_stat) & 0x01;
  42 }
  43
  44 static inline int i2c_is_busy(struct i2c_adapter *i2c_adap)
  45 {
  46         struct cx23885_i2c *bus = i2c_adap->algo_data;
  47         struct cx23885_dev *dev = bus->dev;
  48         return cx_read(bus->reg_stat) & 0x02 ? 1 : 0;
  49 }
  50
  51 static int i2c_wait_done(struct i2c_adapter *i2c_adap)
  52 {
  53         int count;
  54
  55         for (count = 0; count < I2C_WAIT_RETRY; count++) {
  56                 if (!i2c_is_busy(i2c_adap))
  57                         break;
  58                 udelay(I2C_WAIT_DELAY);
  59         }
  60
  61         if (I2C_WAIT_RETRY == count)
  62                 return 0;
  63
  64         return 1;
  65 }
  66
  67 static int i2c_sendbytes(struct i2c_adapter *i2c_adap,
  68                          const struct i2c_msg *msg, int joined_rlen)
  69 {
  70         struct cx23885_i2c *bus = i2c_adap->algo_data;
  71         struct cx23885_dev *dev = bus->dev;
  72         u32 wdata, addr, ctrl;
  73         int retval, cnt;
  74
  75         if (joined_rlen)
  76                 dprintk(1, "%s(msg->wlen=%d, nextmsg->rlen=%d)\n", __func__,
  77                         msg->len, joined_rlen);
  78         else
  79                 dprintk(1, "%s(msg->len=%d)\n", __func__, msg->len);
  80
  81         /* Deal with i2c probe functions with zero payload */
  82         if (msg->len == 0) {
  83                 cx_write(bus->reg_addr, msg->addr << 25);
  84                 cx_write(bus->reg_ctrl, bus->i2c_period | (1 << 2));
  85                 if (!i2c_wait_done(i2c_adap))
  86                         return -EIO;
  87                 if (!i2c_slave_did_ack(i2c_adap))
  88                         return -ENXIO;
  89
  90                 dprintk(1, "%s() returns 0\n", __func__);
  91                 return 0;
  92         }
  93
  94
  95         /* dev, reg + first byte */
  96         addr = (msg->addr << 25) | msg->buf[0];
  97         wdata = msg->buf[0];
  98         ctrl = bus->i2c_period | (1 << 12) | (1 << 2);
  99
 100         if (msg->len > 1)
 101                 ctrl |= I2C_NOSTOP | I2C_EXTEND;
 102         else if (joined_rlen)
 103                 ctrl |= I2C_NOSTOP;
 104
 105         cx_write(bus->reg_addr, addr);
 106         cx_write(bus->reg_wdata, wdata);
 107         cx_write(bus->reg_ctrl, ctrl);
 108
 109         if (!i2c_wait_done(i2c_adap))
 110                 goto eio;
 111         if (i2c_debug) {
 112                 printk(KERN_DEBUG " <W %02x %02x", msg->addr << 1, msg->buf[0]);
 113                 if (!(ctrl & I2C_NOSTOP))
 114                         pr_cont(" >\n");
 115         }
 116
 117         for (cnt = 1; cnt < msg->len; cnt++) {
 118                 /* following bytes */
 119                 wdata = msg->buf[cnt];
 120                 ctrl = bus->i2c_period | (1 << 12) | (1 << 2);
 121
 122                 if (cnt < msg->len - 1)
 123                         ctrl |= I2C_NOSTOP | I2C_EXTEND;
 124                 else if (joined_rlen)
 125                         ctrl |= I2C_NOSTOP;
 126
 127                 cx_write(bus->reg_addr, addr);
 128                 cx_write(bus->reg_wdata, wdata);
 129                 cx_write(bus->reg_ctrl, ctrl);
 130
 131                 if (!i2c_wait_done(i2c_adap))
 132                         goto eio;
 133                 if (i2c_debug) {
 134                         pr_cont(" %02x", msg->buf[cnt]);
 135                         if (!(ctrl & I2C_NOSTOP))
 136                                 pr_cont(" >\n");
 137                 }
 138         }
 139         return msg->len;
 140
 141  eio:
 142         retval = -EIO;
 143         if (i2c_debug)
 144                 pr_err(" ERR: %d\n", retval);
 145         return retval;
 146 }
 147
 148 static int i2c_readbytes(struct i2c_adapter *i2c_adap,
 149                          const struct i2c_msg *msg, int joined)
 150 {
 151         struct cx23885_i2c *bus = i2c_adap->algo_data;
 152         struct cx23885_dev *dev = bus->dev;
 153         u32 ctrl, cnt;
 154         int retval;
 155
 156
 157         if (i2c_debug && !joined)
 158                 dprintk(1, "%s(msg->len=%d)\n", __func__, msg->len);
 159
 160         /* Deal with i2c probe functions with zero payload */
 161         if (msg->len == 0) {
 162                 cx_write(bus->reg_addr, msg->addr << 25);
 163                 cx_write(bus->reg_ctrl, bus->i2c_period | (1 << 2) | 1);
 164                 if (!i2c_wait_done(i2c_adap))
 165                         return -EIO;
 166                 if (!i2c_slave_did_ack(i2c_adap))
 167                         return -ENXIO;
 168
 169
 170                 dprintk(1, "%s() returns 0\n", __func__);
 171                 return 0;
 172         }
 173
 174         if (i2c_debug) {
 175                 if (joined)
 176                         dprintk(1, " R");
 177                 else
 178                         dprintk(1, " <R %02x", (msg->addr << 1) + 1);
 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)
 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                 if (!i2c_wait_done(i2c_adap))
 192                         goto eio;
 193                 msg->buf[cnt] = cx_read(bus->reg_rdata) & 0xff;
 194                 if (i2c_debug) {
 195                         dprintk(1, " %02x", msg->buf[cnt]);
 196                         if (!(ctrl & I2C_NOSTOP))
 197                                 dprintk(1, " >\n");
 198                 }
 199         }
 200         return msg->len;
 201
 202  eio:
 203         retval = -EIO;
 204         if (i2c_debug)
 205                 pr_err(" ERR: %d\n", retval);
 206         return retval;
 207 }
 208
 209 static int i2c_xfer(struct i2c_adapter *i2c_adap,
 210                     struct i2c_msg *msgs, int num)
 211 {
 212         int i, retval = 0;
 213
 214         dprintk(1, "%s(num = %d)\n", __func__, num);
 215
 216         for (i = 0 ; i < num; i++) {
 217                 dprintk(1, "%s(num = %d) addr = 0x%02x  len = 0x%x\n",
 218                         __func__, num, msgs[i].addr, msgs[i].len);
 219                 if (msgs[i].flags & I2C_M_RD) {
 220                         /* read */
 221                         retval = i2c_readbytes(i2c_adap, &msgs[i], 0);
 222                 } else if (i + 1 < num && (msgs[i + 1].flags & I2C_M_RD) &&
 223                            msgs[i].addr == msgs[i + 1].addr) {
 224                         /* write then read from same address */
 225                         retval = i2c_sendbytes(i2c_adap, &msgs[i],
 226                                                msgs[i + 1].len);
 227                         if (retval < 0)
 228                                 goto err;
 229                         i++;
 230                         retval = i2c_readbytes(i2c_adap, &msgs[i], 1);
 231                 } else {
 232                         /* write */
 233                         retval = i2c_sendbytes(i2c_adap, &msgs[i], 0);
 234                 }
 235                 if (retval < 0)
 236                         goto err;
 237         }
 238         return num;
 239
 240  err:
 241         return retval;
 242 }
 243
 244 static u32 cx23885_functionality(struct i2c_adapter *adap)
 245 {
 246         return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_I2C;
 247 }
 248
 249 static const struct i2c_algorithm cx23885_i2c_algo_template = {
 250         .master_xfer    = i2c_xfer,
 251         .functionality  = cx23885_functionality,
 252 };
 253
 254 /* ----------------------------------------------------------------------- */
 255
 256 static const struct i2c_adapter cx23885_i2c_adap_template = {
 257         .name              = "cx23885",
 258         .owner             = THIS_MODULE,
 259         .algo              = &cx23885_i2c_algo_template,
 260 };
 261
 262 static const struct i2c_client cx23885_i2c_client_template = {
 263         .name   = "cx23885 internal",
 264 };
 265
 266 static char *i2c_devs[128] = {
 267         [0x10 >> 1] = "tda10048",
 268         [0x12 >> 1] = "dib7000pc",
 269         [0x1c >> 1] = "lgdt3303",
 270         [0x80 >> 1] = "cs3308",
 271         [0x82 >> 1] = "cs3308",
 272         [0x86 >> 1] = "tda9887",
 273         [0x32 >> 1] = "cx24227",
 274         [0x88 >> 1] = "cx25837",
 275         [0x84 >> 1] = "tda8295",
 276         [0x98 >> 1] = "flatiron",
 277         [0xa0 >> 1] = "eeprom",
 278         [0xc0 >> 1] = "tuner/mt2131/tda8275",
 279         [0xc2 >> 1] = "tuner/mt2131/tda8275/xc5000/xc3028",
 280         [0xc8 >> 1] = "tuner/xc3028L",
 281 };
 282
 283 static void do_i2c_scan(char *name, struct i2c_client *c)
 284 {
 285         unsigned char buf;
 286         int i, rc;
 287
 288         for (i = 0; i < 128; i++) {
 289                 c->addr = i;
 290                 rc = i2c_master_recv(c, &buf, 0);
 291                 if (rc < 0)
 292                         continue;
 293                 pr_info("%s: i2c scan: found device @ 0x%04x  [%s]\n",
 294                        name, i, i2c_devs[i] ? i2c_devs[i] : "???");
 295         }
 296 }
 297
 298 /* init + register i2c adapter */
 299 int cx23885_i2c_register(struct cx23885_i2c *bus)
 300 {
 301         struct cx23885_dev *dev = bus->dev;
 302
 303         dprintk(1, "%s(bus = %d)\n", __func__, bus->nr);
 304
 305         bus->i2c_adap = cx23885_i2c_adap_template;
 306         bus->i2c_client = cx23885_i2c_client_template;
 307         bus->i2c_adap.dev.parent = &dev->pci->dev;
 308
 309         strscpy(bus->i2c_adap.name, bus->dev->name,
 310                 sizeof(bus->i2c_adap.name));
 311
 312         bus->i2c_adap.algo_data = bus;
 313         i2c_set_adapdata(&bus->i2c_adap, &dev->v4l2_dev);
 314         i2c_add_adapter(&bus->i2c_adap);
 315
 316         bus->i2c_client.adapter = &bus->i2c_adap;
 317
 318         if (0 == bus->i2c_rc) {
 319                 dprintk(1, "%s: i2c bus %d registered\n", dev->name, bus->nr);
 320                 if (i2c_scan) {
 321                         pr_info("%s: scan bus %d:\n",
 322                                         dev->name, bus->nr);
 323                         do_i2c_scan(dev->name, &bus->i2c_client);
 324                 }
 325         } else
 326                 pr_warn("%s: i2c bus %d register FAILED\n",
 327                         dev->name, bus->nr);
 328
 329         /* Instantiate the IR receiver device, if present */
 330         if (0 == bus->i2c_rc) {
 331                 struct i2c_board_info info;
 332                 static const unsigned short addr_list[] = {
 333                         0x6b, I2C_CLIENT_END
 334                 };
 335
 336                 memset(&info, 0, sizeof(struct i2c_board_info));
 337                 strscpy(info.type, "ir_video", I2C_NAME_SIZE);
 338                 /* Use quick read command for probe, some IR chips don't
 339                  * support writes */
 340                 i2c_new_scanned_device(&bus->i2c_adap, &info, addr_list,
 341                                        i2c_probe_func_quick_read);
 342         }
 343
 344         return bus->i2c_rc;
 345 }
 346
 347 int cx23885_i2c_unregister(struct cx23885_i2c *bus)
 348 {
 349         i2c_del_adapter(&bus->i2c_adap);
 350         return 0;
 351 }
 352
 353 void cx23885_av_clk(struct cx23885_dev *dev, int enable)
 354 {
 355         /* write 0 to bus 2 addr 0x144 via i2x_xfer() */
 356         char buffer[3];
 357         struct i2c_msg msg;
 358         dprintk(1, "%s(enabled = %d)\n", __func__, enable);
 359
 360         /* Register 0x144 */
 361         buffer[0] = 0x01;
 362         buffer[1] = 0x44;
 363         if (enable == 1)
 364                 buffer[2] = 0x05;
 365         else
 366                 buffer[2] = 0x00;
 367
 368         msg.addr = 0x44;
 369         msg.flags = I2C_M_TEN;
 370         msg.len = 3;
 371         msg.buf = buffer;
 372
 373         i2c_xfer(&dev->i2c_bus[2].i2c_adap, &msg, 1);
 374 }