1da177e4c3
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
283 lines
7.1 KiB
C
283 lines
7.1 KiB
C
/*
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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/config.h>
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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 <linux/wait.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;
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static int irq;
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static int clock;
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static int own;
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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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static spinlock_t lock;
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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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pr_debug(" Write 0x%02x to 0x%x\n",(unsigned short)val, ctl&0xff);
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#ifdef DEBUG
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while (time_before(jiffies, j))
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schedule();
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#endif
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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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pr_debug("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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/* 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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DEFINE_WAIT(wait);
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int timeout = 2;
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long flags;
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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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spin_lock_irqsave(&lock, flags);
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if (iic_pending == 0) {
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spin_unlock_irqrestore(&lock, flags);
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prepare_to_wait(&iic_wait, &wait, TASK_INTERRUPTIBLE);
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if (schedule_timeout(timeout*HZ)) {
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spin_lock_irqsave(&lock, flags);
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if (iic_pending == 1) {
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iic_pending = 0;
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}
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spin_unlock_irqrestore(&lock, flags);
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}
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finish_wait(&iic_wait, &wait);
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} else {
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iic_pending = 0;
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spin_unlock_irqrestore(&lock, flags);
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}
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} else {
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udelay(100);
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}
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}
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static irqreturn_t iic_ite_handler(int this_irq, void *dev_id,
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struct pt_regs *regs)
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{
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spin_lock(&lock);
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iic_pending = 1;
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spin_unlock(&lock);
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wake_up_interruptible(&iic_wait);
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return IRQ_HANDLED;
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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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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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*/
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static int __init iic_ite_init(void)
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{
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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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spin_lock_init(&lock);
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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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}
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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;
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}
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static void iic_ite_exit(void)
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{
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i2c_iic_del_bus(&iic_ite_ops);
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iic_ite_release();
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}
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/* 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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*/
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MODULE_AUTHOR("MontaVista Software <www.mvista.com>");
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MODULE_DESCRIPTION("I2C-Bus adapter routines for ITE IIC bus adapter");
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MODULE_LICENSE("GPL");
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module_param(base, int, 0);
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module_param(irq, int, 0);
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module_param(clock, int, 0);
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module_param(own, int, 0);
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/* 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
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* 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.
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*/
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module_init(iic_ite_init);
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/* Resolves to module_cleanup when MODULES is defined. */
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module_exit(iic_ite_exit);
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