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420 giacomo 1
/*
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   -------------------------------------------------------------------------
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   i2c-adap-ite.c i2c-hw access for the IIC peripheral on the ITE MIPS system
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   -------------------------------------------------------------------------
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   Hai-Pao Fan, MontaVista Software, Inc.
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   hpfan@mvista.com or source@mvista.com
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   Copyright 2001 MontaVista Software Inc.
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   ----------------------------------------------------------------------------
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   This file was highly leveraged from i2c-elektor.c, which was created
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   by Simon G. Vogl and Hans Berglund:
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     Copyright (C) 1995-97 Simon G. Vogl
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                   1998-99 Hans Berglund
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    This program is free software; you can redistribute it and/or modify
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    it under the terms of the GNU General Public License as published by
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    the Free Software Foundation; either version 2 of the License, or
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    (at your option) any later version.
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    This program is distributed in the hope that it will be useful,
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    but WITHOUT ANY WARRANTY; without even the implied warranty of
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    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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    GNU General Public License for more details.
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    You should have received a copy of the GNU General Public License
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    along with this program; if not, write to the Free Software
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    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.                */
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/* ------------------------------------------------------------------------- */
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/* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and even
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   Frodo Looijaard <frodol@dds.nl> */
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#include <linux/kernel.h>
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#include <linux/ioport.h>
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#include <linux/module.h>
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#include <linux/delay.h>
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#include <linux/slab.h>
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#include <linux/init.h>
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#include <asm/irq.h>
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#include <asm/io.h>
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#include <linux/i2c.h>
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#include <linux/i2c-algo-ite.h>
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#include <linux/i2c-adap-ite.h>
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#include "../i2c-ite.h"
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#define DEFAULT_BASE  0x14014030
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#define ITE_IIC_IO_SIZE 0x40
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#define DEFAULT_IRQ   0
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#define DEFAULT_CLOCK 0x1b0e    /* default 16MHz/(27+14) = 400KHz */
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#define DEFAULT_OWN   0x55
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static int base  = 0;
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static int irq   = 0;
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static int clock = 0;
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static int own   = 0;
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static int i2c_debug=0;
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static struct iic_ite gpi;
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static wait_queue_head_t iic_wait;
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static int iic_pending;
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/* ----- global defines ----------------------------------------------- */
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#define DEB(x)  if (i2c_debug>=1) x
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#define DEB2(x) if (i2c_debug>=2) x
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#define DEB3(x) if (i2c_debug>=3) x
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#define DEBE(x) x       /* error messages                               */
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/* ----- local functions ---------------------------------------------- */
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static void iic_ite_setiic(void *data, int ctl, short val)
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{
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        unsigned long j = jiffies + 10;
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        DEB3(printk(" Write 0x%02x to 0x%x\n",(unsigned short)val, ctl&0xff));
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        DEB3({while (time_before(jiffies, j)) schedule();})
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        outw(val,ctl);
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}
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static short iic_ite_getiic(void *data, int ctl)
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{
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        short val;
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        val = inw(ctl);
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        DEB3(printk("Read 0x%02x from 0x%x\n",(unsigned short)val, ctl&0xff));  
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        return (val);
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}
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/* Return our slave address.  This is the address
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 * put on the I2C bus when another master on the bus wants to address us
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 * as a slave
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 */
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static int iic_ite_getown(void *data)
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{
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        return (gpi.iic_own);
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}
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static int iic_ite_getclock(void *data)
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{
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        return (gpi.iic_clock);
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}
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#if 0
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static void iic_ite_sleep(unsigned long timeout)
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{
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        schedule_timeout( timeout * HZ);
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}
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#endif
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/* Put this process to sleep.  We will wake up when the
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 * IIC controller interrupts.
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 */
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static void iic_ite_waitforpin(void) {
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122
   int timeout = 2;
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   /* If interrupts are enabled (which they are), then put the process to
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    * sleep.  This process will be awakened by two events -- either the
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    * the IIC peripheral interrupts or the timeout expires.
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    * If interrupts are not enabled then delay for a reasonable amount
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    * of time and return.
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    */
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   if (gpi.iic_irq > 0) {
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        cli();
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        if (iic_pending == 0) {
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                interruptible_sleep_on_timeout(&iic_wait, timeout*HZ );
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        } else
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                iic_pending = 0;
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        sti();
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   } else {
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      udelay(100);
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   }
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}
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143
static void iic_ite_handler(int this_irq, void *dev_id, struct pt_regs *regs)
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{
145
 
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   iic_pending = 1;
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148
   DEB2(printk("iic_ite_handler: in interrupt handler\n"));
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   wake_up_interruptible(&iic_wait);
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}
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/* Lock the region of memory where I/O registers exist.  Request our
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 * interrupt line and register its associated handler.
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 */
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static int iic_hw_resrc_init(void)
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{
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        if (!request_region(gpi.iic_base, ITE_IIC_IO_SIZE, "i2c"))
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                return -ENODEV;
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        if (gpi.iic_irq <= 0)
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                return 0;
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        if (request_irq(gpi.iic_irq, iic_ite_handler, 0, "ITE IIC", 0) < 0)
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                gpi.iic_irq = 0;
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        else
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                enable_irq(gpi.iic_irq);
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        return 0;
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}
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173
static void iic_ite_release(void)
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{
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        if (gpi.iic_irq > 0) {
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                disable_irq(gpi.iic_irq);
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                free_irq(gpi.iic_irq, 0);
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        }
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        release_region(gpi.iic_base , 2);
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}
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/* ------------------------------------------------------------------------
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 * Encapsulate the above functions in the correct operations structure.
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 * This is only done when more than one hardware adapter is supported.
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 */
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static struct i2c_algo_iic_data iic_ite_data = {
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        NULL,
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        iic_ite_setiic,
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        iic_ite_getiic,
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        iic_ite_getown,
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        iic_ite_getclock,
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        iic_ite_waitforpin,
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        80, 80, 100,            /*      waits, timeout */
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};
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static struct i2c_adapter iic_ite_ops = {
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        .owner          = THIS_MODULE,
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        .id             = I2C_HW_I_IIC,
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        .algo_data      = &iic_ite_data,
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        .dev            = {
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                .name   = "ITE IIC adapter",
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        },
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};
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/* Called when the module is loaded.  This function starts the
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 * cascade of calls up through the hierarchy of i2c modules (i.e. up to the
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 *  algorithm layer and into to the core layer)
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 */
209
static int __init iic_ite_init(void)
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{
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212
        struct iic_ite *piic = &gpi;
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        printk(KERN_INFO "Initialize ITE IIC adapter module\n");
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        if (base == 0)
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                piic->iic_base = DEFAULT_BASE;
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        else
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                piic->iic_base = base;
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        if (irq == 0)
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                piic->iic_irq = DEFAULT_IRQ;
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        else
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                piic->iic_irq = irq;
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        if (clock == 0)
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                piic->iic_clock = DEFAULT_CLOCK;
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        else
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                piic->iic_clock = clock;
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        if (own == 0)
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                piic->iic_own = DEFAULT_OWN;
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        else
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                piic->iic_own = own;
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        iic_ite_data.data = (void *)piic;
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        init_waitqueue_head(&iic_wait);
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        if (iic_hw_resrc_init() == 0) {
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                if (i2c_iic_add_bus(&iic_ite_ops) < 0)
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                        return -ENODEV;
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        } else {
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                return -ENODEV;
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        }
243
        printk(KERN_INFO " found device at %#x irq %d.\n",
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                piic->iic_base, piic->iic_irq);
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        return 0;
246
}
247
 
248
 
249
static void iic_ite_exit(void)
250
{
251
        i2c_iic_del_bus(&iic_ite_ops);
252
        iic_ite_release();
253
}
254
 
255
/* If modules is NOT defined when this file is compiled, then the MODULE_*
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 * macros will resolve to nothing
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 */
258
MODULE_AUTHOR("MontaVista Software <www.mvista.com>");
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MODULE_DESCRIPTION("I2C-Bus adapter routines for ITE IIC bus adapter");
260
MODULE_LICENSE("GPL");
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262
MODULE_PARM(base, "i");
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MODULE_PARM(irq, "i");
264
MODULE_PARM(clock, "i");
265
MODULE_PARM(own, "i");
266
MODULE_PARM(i2c_debug,"i");
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268
 
269
/* Called when module is loaded or when kernel is initialized.
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 * If MODULES is defined when this file is compiled, then this function will
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 * resolve to init_module (the function called when insmod is invoked for a
272
 * module).  Otherwise, this function is called early in the boot, when the
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 * kernel is intialized.  Check out /include/init.h to see how this works.
274
 */
275
module_init(iic_ite_init);
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/* Resolves to module_cleanup when MODULES is defined. */
278
module_exit(iic_ite_exit);