drivers/media/pci/saa7164/saa7164-i2c.c

   1 /*
   2  *  Driver for the NXP SAA7164 PCIe bridge
   3  *
   4  *  Copyright (c) 2010-2015 Steven Toth <stoth@kernellabs.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
  18 #include <linux/module.h>
  19 #include <linux/moduleparam.h>
  20 #include <linux/init.h>
  21 #include <linux/delay.h>
  22 #include <linux/io.h>
  23
  24 #include "saa7164.h"
  25
  26 static int i2c_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs, int num)
  27 {
  28         struct saa7164_i2c *bus = i2c_adap->algo_data;
  29         struct saa7164_dev *dev = bus->dev;
  30         int i, retval = 0;
  31
  32         dprintk(DBGLVL_I2C, "%s(num = %d)\n", __func__, num);
  33
  34         for (i = 0 ; i < num; i++) {
  35                 dprintk(DBGLVL_I2C, "%s(num = %d) addr = 0x%02x  len = 0x%x\n",
  36                         __func__, num, msgs[i].addr, msgs[i].len);
  37                 if (msgs[i].flags & I2C_M_RD) {
  38                         retval = saa7164_api_i2c_read(bus,
  39                                 msgs[i].addr,
  40                                 0 /* reglen */,
  41                                 NULL /* reg */, msgs[i].len, msgs[i].buf);
  42                 } else if (i + 1 < num && (msgs[i + 1].flags & I2C_M_RD) &&
  43                            msgs[i].addr == msgs[i + 1].addr) {
  44                         /* write then read from same address */
  45
  46                         retval = saa7164_api_i2c_read(bus, msgs[i].addr,
  47                                 msgs[i].len, msgs[i].buf,
  48                                 msgs[i+1].len, msgs[i+1].buf
  49                                 );
  50
  51                         i++;
  52
  53                         if (retval < 0)
  54                                 goto err;
  55                 } else {
  56                         /* write */
  57                         retval = saa7164_api_i2c_write(bus, msgs[i].addr,
  58                                 msgs[i].len, msgs[i].buf);
  59                 }
  60                 if (retval < 0)
  61                         goto err;
  62         }
  63         return num;
  64
  65 err:
  66         return retval;
  67 }
  68
  69 static u32 saa7164_functionality(struct i2c_adapter *adap)
  70 {
  71         return I2C_FUNC_I2C;
  72 }
  73
  74 static const struct i2c_algorithm saa7164_i2c_algo_template = {
  75         .master_xfer    = i2c_xfer,
  76         .functionality  = saa7164_functionality,
  77 };
  78
  79 /* ----------------------------------------------------------------------- */
  80
  81 static const struct i2c_adapter saa7164_i2c_adap_template = {
  82         .name              = "saa7164",
  83         .owner             = THIS_MODULE,
  84         .algo              = &saa7164_i2c_algo_template,
  85 };
  86
  87 static const struct i2c_client saa7164_i2c_client_template = {
  88         .name   = "saa7164 internal",
  89 };
  90
  91 int saa7164_i2c_register(struct saa7164_i2c *bus)
  92 {
  93         struct saa7164_dev *dev = bus->dev;
  94
  95         dprintk(DBGLVL_I2C, "%s(bus = %d)\n", __func__, bus->nr);
  96
  97         bus->i2c_adap = saa7164_i2c_adap_template;
  98         bus->i2c_client = saa7164_i2c_client_template;
  99
 100         bus->i2c_adap.dev.parent = &dev->pci->dev;
 101
 102         strlcpy(bus->i2c_adap.name, bus->dev->name,
 103                 sizeof(bus->i2c_adap.name));
 104
 105         bus->i2c_adap.algo_data = bus;
 106         i2c_set_adapdata(&bus->i2c_adap, bus);
 107         i2c_add_adapter(&bus->i2c_adap);
 108
 109         bus->i2c_client.adapter = &bus->i2c_adap;
 110
 111         if (0 != bus->i2c_rc)
 112                 printk(KERN_ERR "%s: i2c bus %d register FAILED\n",
 113                         dev->name, bus->nr);
 114
 115         return bus->i2c_rc;
 116 }
 117
 118 int saa7164_i2c_unregister(struct saa7164_i2c *bus)
 119 {
 120         i2c_del_adapter(&bus->i2c_adap);
 121         return 0;
 122 }