linux/drivers/media/video/saa7164/saa7164-i2c.c
<<
>>
Prefs
   1/*
   2 *  Driver for the NXP SAA7164 PCIe bridge
   3 *
   4 *  Copyright (c) 2009 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 *  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 "saa7164.h"
  29
  30static int i2c_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs, int num)
  31{
  32        struct saa7164_i2c *bus = i2c_adap->algo_data;
  33        struct saa7164_dev *dev = bus->dev;
  34        int i, retval = 0;
  35
  36        dprintk(DBGLVL_I2C, "%s(num = %d)\n", __func__, num);
  37
  38        for (i = 0 ; i < num; i++) {
  39                dprintk(DBGLVL_I2C, "%s(num = %d) addr = 0x%02x  len = 0x%x\n",
  40                        __func__, num, msgs[i].addr, msgs[i].len);
  41                if (msgs[i].flags & I2C_M_RD) {
  42                        /* Unsupported - Yet*/
  43                        printk(KERN_ERR "%s() Unsupported - Yet\n", __func__);
  44                        continue;
  45                } else if (i + 1 < num && (msgs[i + 1].flags & I2C_M_RD) &&
  46                           msgs[i].addr == msgs[i + 1].addr) {
  47                        /* write then read from same address */
  48
  49                        retval = saa7164_api_i2c_read(bus, msgs[i].addr,
  50                                msgs[i].len, msgs[i].buf,
  51                                msgs[i+1].len, msgs[i+1].buf
  52                                );
  53
  54                        i++;
  55
  56                        if (retval < 0)
  57                                goto err;
  58                } else {
  59                        /* write */
  60                        retval = saa7164_api_i2c_write(bus, msgs[i].addr,
  61                                msgs[i].len, msgs[i].buf);
  62                }
  63                if (retval < 0)
  64                        goto err;
  65        }
  66        return num;
  67
  68 err:
  69        return retval;
  70}
  71
  72void saa7164_call_i2c_clients(struct saa7164_i2c *bus, unsigned int cmd,
  73        void *arg)
  74{
  75        if (bus->i2c_rc != 0)
  76                return;
  77
  78        i2c_clients_command(&bus->i2c_adap, cmd, arg);
  79}
  80
  81static u32 saa7164_functionality(struct i2c_adapter *adap)
  82{
  83        return I2C_FUNC_I2C;
  84}
  85
  86static struct i2c_algorithm saa7164_i2c_algo_template = {
  87        .master_xfer    = i2c_xfer,
  88        .functionality  = saa7164_functionality,
  89};
  90
  91/* ----------------------------------------------------------------------- */
  92
  93static struct i2c_adapter saa7164_i2c_adap_template = {
  94        .name              = "saa7164",
  95        .owner             = THIS_MODULE,
  96        .algo              = &saa7164_i2c_algo_template,
  97};
  98
  99static struct i2c_client saa7164_i2c_client_template = {
 100        .name   = "saa7164 internal",
 101};
 102
 103int saa7164_i2c_register(struct saa7164_i2c *bus)
 104{
 105        struct saa7164_dev *dev = bus->dev;
 106
 107        dprintk(DBGLVL_I2C, "%s(bus = %d)\n", __func__, bus->nr);
 108
 109        memcpy(&bus->i2c_adap, &saa7164_i2c_adap_template,
 110               sizeof(bus->i2c_adap));
 111
 112        memcpy(&bus->i2c_algo, &saa7164_i2c_algo_template,
 113               sizeof(bus->i2c_algo));
 114
 115        memcpy(&bus->i2c_client, &saa7164_i2c_client_template,
 116               sizeof(bus->i2c_client));
 117
 118        bus->i2c_adap.dev.parent = &dev->pci->dev;
 119
 120        strlcpy(bus->i2c_adap.name, bus->dev->name,
 121                sizeof(bus->i2c_adap.name));
 122
 123        bus->i2c_algo.data = bus;
 124        bus->i2c_adap.algo_data = bus;
 125        i2c_set_adapdata(&bus->i2c_adap, bus);
 126        i2c_add_adapter(&bus->i2c_adap);
 127
 128        bus->i2c_client.adapter = &bus->i2c_adap;
 129
 130        if (0 != bus->i2c_rc)
 131                printk(KERN_ERR "%s: i2c bus %d register FAILED\n",
 132                        dev->name, bus->nr);
 133
 134        return bus->i2c_rc;
 135}
 136
 137int saa7164_i2c_unregister(struct saa7164_i2c *bus)
 138{
 139        i2c_del_adapter(&bus->i2c_adap);
 140        return 0;
 141}
 142