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

   1/*
   2 *  Driver for the NXP SAA7164 PCIe bridge
   3 *
   4 *  Copyright (c) 2010 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 <linux/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
  68err:
  69        return retval;
  70}
  71
  72static u32 saa7164_functionality(struct i2c_adapter *adap)
  73{
  74        return I2C_FUNC_I2C;
  75}
  76
  77static struct i2c_algorithm saa7164_i2c_algo_template = {
  78        .master_xfer    = i2c_xfer,
  79        .functionality  = saa7164_functionality,
  80};
  81
  82/* ----------------------------------------------------------------------- */
  83
  84static struct i2c_adapter saa7164_i2c_adap_template = {
  85        .name              = "saa7164",
  86        .owner             = THIS_MODULE,
  87        .algo              = &saa7164_i2c_algo_template,
  88};
  89
  90static struct i2c_client saa7164_i2c_client_template = {
  91        .name   = "saa7164 internal",
  92};
  93
  94int saa7164_i2c_register(struct saa7164_i2c *bus)
  95{
  96        struct saa7164_dev *dev = bus->dev;
  97
  98        dprintk(DBGLVL_I2C, "%s(bus = %d)\n", __func__, bus->nr);
  99
 100        bus->i2c_adap = saa7164_i2c_adap_template;
 101        bus->i2c_client = saa7164_i2c_client_template;
 102
 103        bus->i2c_adap.dev.parent = &dev->pci->dev;
 104
 105        strlcpy(bus->i2c_adap.name, bus->dev->name,
 106                sizeof(bus->i2c_adap.name));
 107
 108        bus->i2c_adap.algo_data = bus;
 109        i2c_set_adapdata(&bus->i2c_adap, bus);
 110        i2c_add_adapter(&bus->i2c_adap);
 111
 112        bus->i2c_client.adapter = &bus->i2c_adap;
 113
 114        if (0 != bus->i2c_rc)
 115                printk(KERN_ERR "%s: i2c bus %d register FAILED\n",
 116                        dev->name, bus->nr);
 117
 118        return bus->i2c_rc;
 119}
 120
 121int saa7164_i2c_unregister(struct saa7164_i2c *bus)
 122{
 123        i2c_del_adapter(&bus->i2c_adap);
 124        return 0;
 125}
 126