drivers/i2c/busses/i2c-ite.c - kernel/msm-5.4 - Gitiles

 /*
    -------------------------------------------------------------------------
    i2c-adap-ite.c i2c-hw access for the IIC peripheral on the ITE MIPS system
    -------------------------------------------------------------------------
    Hai-Pao Fan, MontaVista Software, Inc.
    hpfan@mvista.com or source@mvista.com

    Copyright 2001 MontaVista Software Inc.

    ----------------------------------------------------------------------------
    This file was highly leveraged from i2c-elektor.c, which was created
    by Simon G. Vogl and Hans Berglund:


      Copyright (C) 1995-97 Simon G. Vogl
                    1998-99 Hans Berglund

     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
     the Free Software Foundation; either version 2 of the License, or
     (at your option) any later version.

     This program is distributed in the hope that it will be useful,
     but WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     GNU General Public License for more details.

     You should have received a copy of the GNU General Public License
     along with this program; if not, write to the Free Software
     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.		     */
 /* ------------------------------------------------------------------------- */

 /* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and even
    Frodo Looijaard <frodol@dds.nl> */

 #include <linux/kernel.h>
 #include <linux/ioport.h>
 #include <linux/module.h>
 #include <linux/delay.h>
 #include <linux/slab.h>
 #include <linux/init.h>
 #include <linux/wait.h>
 #include <asm/irq.h>
 #include <asm/io.h>

 #include <linux/i2c.h>
 #include <linux/i2c-algo-ite.h>
 #include <linux/i2c-adap-ite.h>
 #include "../i2c-ite.h"

 #define DEFAULT_BASE  0x14014030
 #define ITE_IIC_IO_SIZE	0x40
 #define DEFAULT_IRQ   0
 #define DEFAULT_CLOCK 0x1b0e	/* default 16MHz/(27+14) = 400KHz */
 #define DEFAULT_OWN   0x55

 static int base;
 static int irq;
 static int clock;
 static int own;

 static struct iic_ite gpi;
 static wait_queue_head_t iic_wait;
 static int iic_pending;
 static spinlock_t lock;

 /* ----- local functions ----------------------------------------------	*/

 static void iic_ite_setiic(void *data, int ctl, short val)
 {
         unsigned long j = jiffies + 10;

 	pr_debug(" Write 0x%02x to 0x%x\n",(unsigned short)val, ctl&0xff);
 #ifdef DEBUG
 	while (time_before(jiffies, j))
 		schedule();
 #endif
 	outw(val,ctl);
 }

 static short iic_ite_getiic(void *data, int ctl)
 {
 	short val;

 	val = inw(ctl);
 	pr_debug("Read 0x%02x from 0x%x\n",(unsigned short)val, ctl&0xff);
 	return (val);
 }

 /* Return our slave address.  This is the address
  * put on the I2C bus when another master on the bus wants to address us
  * as a slave
  */
 static int iic_ite_getown(void *data)
 {
 	return (gpi.iic_own);
 }


 static int iic_ite_getclock(void *data)
 {
 	return (gpi.iic_clock);
 }


 /* Put this process to sleep.  We will wake up when the
  * IIC controller interrupts.
  */
 static void iic_ite_waitforpin(void) {
    DEFINE_WAIT(wait);
    int timeout = 2;
    unsigned long flags;

    /* If interrupts are enabled (which they are), then put the process to
     * sleep.  This process will be awakened by two events -- either the
     * the IIC peripheral interrupts or the timeout expires.
     * If interrupts are not enabled then delay for a reasonable amount
     * of time and return.
     */
    if (gpi.iic_irq > 0) {
 	spin_lock_irqsave(&lock, flags);
 	if (iic_pending == 0) {
 		spin_unlock_irqrestore(&lock, flags);
 		prepare_to_wait(&iic_wait, &wait, TASK_INTERRUPTIBLE);
 		if (schedule_timeout(timeout*HZ)) {
 			spin_lock_irqsave(&lock, flags);
 			if (iic_pending == 1) {
 				iic_pending = 0;
 			}
 			spin_unlock_irqrestore(&lock, flags);
 		}
 		finish_wait(&iic_wait, &wait);
 	} else {
 		iic_pending = 0;
 		spin_unlock_irqrestore(&lock, flags);
 	}
    } else {
       udelay(100);
    }
 }


 static irqreturn_t iic_ite_handler(int this_irq, void *dev_id,
 							struct pt_regs *regs)
 {
 	spin_lock(&lock);
 	iic_pending = 1;
 	spin_unlock(&lock);

 	wake_up_interruptible(&iic_wait);

 	return IRQ_HANDLED;
 }


 /* Lock the region of memory where I/O registers exist.  Request our
  * interrupt line and register its associated handler.
  */
 static int iic_hw_resrc_init(void)
 {
 	if (!request_region(gpi.iic_base, ITE_IIC_IO_SIZE, "i2c"))
 		return -ENODEV;

 	if (gpi.iic_irq <= 0)
 		return 0;

 	if (request_irq(gpi.iic_irq, iic_ite_handler, 0, "ITE IIC", 0) < 0)
 		gpi.iic_irq = 0;
 	else
 		enable_irq(gpi.iic_irq);

 	return 0;
 }


 static void iic_ite_release(void)
 {
 	if (gpi.iic_irq > 0) {
 		disable_irq(gpi.iic_irq);
 		free_irq(gpi.iic_irq, 0);
 	}
 	release_region(gpi.iic_base , 2);
 }

 /* ------------------------------------------------------------------------
  * Encapsulate the above functions in the correct operations structure.
  * This is only done when more than one hardware adapter is supported.
  */
 static struct i2c_algo_iic_data iic_ite_data = {
 	NULL,
 	iic_ite_setiic,
 	iic_ite_getiic,
 	iic_ite_getown,
 	iic_ite_getclock,
 	iic_ite_waitforpin,
 	80, 80, 100,		/*	waits, timeout */
 };

 static struct i2c_adapter iic_ite_ops = {
 	.owner		= THIS_MODULE,
 	.id		= I2C_HW_I_IIC,
 	.algo_data	= &iic_ite_data,
 	.name		= "ITE IIC adapter",
 };

 /* Called when the module is loaded.  This function starts the
  * cascade of calls up through the hierarchy of i2c modules (i.e. up to the
  *  algorithm layer and into to the core layer)
  */
 static int __init iic_ite_init(void)
 {

 	struct iic_ite *piic = &gpi;

 	printk(KERN_INFO "Initialize ITE IIC adapter module\n");
 	if (base == 0)
 		piic->iic_base = DEFAULT_BASE;
 	else
 		piic->iic_base = base;

 	if (irq == 0)
 		piic->iic_irq = DEFAULT_IRQ;
 	else
 		piic->iic_irq = irq;

 	if (clock == 0)
 		piic->iic_clock = DEFAULT_CLOCK;
 	else
 		piic->iic_clock = clock;

 	if (own == 0)
 		piic->iic_own = DEFAULT_OWN;
 	else
 		piic->iic_own = own;

 	iic_ite_data.data = (void *)piic;
 	init_waitqueue_head(&iic_wait);
 	spin_lock_init(&lock);
 	if (iic_hw_resrc_init() == 0) {
 		if (i2c_iic_add_bus(&iic_ite_ops) < 0)
 			return -ENODEV;
 	} else {
 		return -ENODEV;
 	}
 	printk(KERN_INFO " found device at %#x irq %d.\n",
 		piic->iic_base, piic->iic_irq);
 	return 0;
 }


 static void iic_ite_exit(void)
 {
 	i2c_iic_del_bus(&iic_ite_ops);
         iic_ite_release();
 }

 /* If modules is NOT defined when this file is compiled, then the MODULE_*
  * macros will resolve to nothing
  */
 MODULE_AUTHOR("MontaVista Software <www.mvista.com>");
 MODULE_DESCRIPTION("I2C-Bus adapter routines for ITE IIC bus adapter");
 MODULE_LICENSE("GPL");

 module_param(base, int, 0);
 module_param(irq, int, 0);
 module_param(clock, int, 0);
 module_param(own, int, 0);


 /* Called when module is loaded or when kernel is initialized.
  * If MODULES is defined when this file is compiled, then this function will
  * resolve to init_module (the function called when insmod is invoked for a
  * module).  Otherwise, this function is called early in the boot, when the
  * kernel is intialized.  Check out /include/init.h to see how this works.
  */
 module_init(iic_ite_init);

 /* Resolves to module_cleanup when MODULES is defined. */
 module_exit(iic_ite_exit);
	/*
	-------------------------------------------------------------------------
	i2c-adap-ite.c i2c-hw access for the IIC peripheral on the ITE MIPS system
	-------------------------------------------------------------------------
	Hai-Pao Fan, MontaVista Software, Inc.
	hpfan@mvista.com or source@mvista.com

	Copyright 2001 MontaVista Software Inc.

	----------------------------------------------------------------------------
	This file was highly leveraged from i2c-elektor.c, which was created
	by Simon G. Vogl and Hans Berglund:


	Copyright (C) 1995-97 Simon G. Vogl
	1998-99 Hans Berglund

	This program is free software; you can redistribute it and/or modify
	it under the terms of the GNU General Public License as published by
	the Free Software Foundation; either version 2 of the License, or
	(at your option) any later version.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	GNU General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with this program; if not, write to the Free Software
	Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
	/* ------------------------------------------------------------------------- */

	/* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and even
	Frodo Looijaard <frodol@dds.nl> */

	#include <linux/kernel.h>
	#include <linux/ioport.h>
	#include <linux/module.h>
	#include <linux/delay.h>
	#include <linux/slab.h>
	#include <linux/init.h>
	#include <linux/wait.h>
	#include <asm/irq.h>
	#include <asm/io.h>

	#include <linux/i2c.h>
	#include <linux/i2c-algo-ite.h>
	#include <linux/i2c-adap-ite.h>
	#include "../i2c-ite.h"

	#define DEFAULT_BASE 0x14014030
	#define ITE_IIC_IO_SIZE 0x40
	#define DEFAULT_IRQ 0
	#define DEFAULT_CLOCK 0x1b0e /* default 16MHz/(27+14) = 400KHz */
	#define DEFAULT_OWN 0x55

	static int base;
	static int irq;
	static int clock;
	static int own;

	static struct iic_ite gpi;
	static wait_queue_head_t iic_wait;
	static int iic_pending;
	static spinlock_t lock;

	/* ----- local functions ---------------------------------------------- */

	static void iic_ite_setiic(void *data, int ctl, short val)
	{
	unsigned long j = jiffies + 10;

	pr_debug(" Write 0x%02x to 0x%x\n",(unsigned short)val, ctl&0xff);
	#ifdef DEBUG
	while (time_before(jiffies, j))
	schedule();
	#endif
	outw(val,ctl);
	}

	static short iic_ite_getiic(void *data, int ctl)
	{
	short val;

	val = inw(ctl);
	pr_debug("Read 0x%02x from 0x%x\n",(unsigned short)val, ctl&0xff);
	return (val);
	}

	/* Return our slave address. This is the address
	* put on the I2C bus when another master on the bus wants to address us
	* as a slave
	*/
	static int iic_ite_getown(void *data)
	{
	return (gpi.iic_own);
	}


	static int iic_ite_getclock(void *data)
	{
	return (gpi.iic_clock);
	}


	/* Put this process to sleep. We will wake up when the
	* IIC controller interrupts.
	*/
	static void iic_ite_waitforpin(void) {
	DEFINE_WAIT(wait);
	int timeout = 2;
	unsigned long flags;

	/* If interrupts are enabled (which they are), then put the process to
	* sleep. This process will be awakened by two events -- either the
	* the IIC peripheral interrupts or the timeout expires.
	* If interrupts are not enabled then delay for a reasonable amount
	* of time and return.
	*/
	if (gpi.iic_irq > 0) {
	spin_lock_irqsave(&lock, flags);
	if (iic_pending == 0) {
	spin_unlock_irqrestore(&lock, flags);
	prepare_to_wait(&iic_wait, &wait, TASK_INTERRUPTIBLE);
	if (schedule_timeout(timeout*HZ)) {
	spin_lock_irqsave(&lock, flags);
	if (iic_pending == 1) {
	iic_pending = 0;
	}
	spin_unlock_irqrestore(&lock, flags);
	}
	finish_wait(&iic_wait, &wait);
	} else {
	iic_pending = 0;
	spin_unlock_irqrestore(&lock, flags);
	}
	} else {
	udelay(100);
	}
	}


	static irqreturn_t iic_ite_handler(int this_irq, void *dev_id,
	struct pt_regs *regs)
	{
	spin_lock(&lock);
	iic_pending = 1;
	spin_unlock(&lock);

	wake_up_interruptible(&iic_wait);

	return IRQ_HANDLED;
	}


	/* Lock the region of memory where I/O registers exist. Request our
	* interrupt line and register its associated handler.
	*/
	static int iic_hw_resrc_init(void)
	{
	if (!request_region(gpi.iic_base, ITE_IIC_IO_SIZE, "i2c"))
	return -ENODEV;

	if (gpi.iic_irq <= 0)
	return 0;

	if (request_irq(gpi.iic_irq, iic_ite_handler, 0, "ITE IIC", 0) < 0)
	gpi.iic_irq = 0;
	else
	enable_irq(gpi.iic_irq);

	return 0;
	}


	static void iic_ite_release(void)
	{
	if (gpi.iic_irq > 0) {
	disable_irq(gpi.iic_irq);
	free_irq(gpi.iic_irq, 0);
	}
	release_region(gpi.iic_base , 2);
	}

	/* ------------------------------------------------------------------------
	* Encapsulate the above functions in the correct operations structure.
	* This is only done when more than one hardware adapter is supported.
	*/
	static struct i2c_algo_iic_data iic_ite_data = {
	NULL,
	iic_ite_setiic,
	iic_ite_getiic,
	iic_ite_getown,
	iic_ite_getclock,
	iic_ite_waitforpin,
	80, 80, 100, /* waits, timeout */
	};

	static struct i2c_adapter iic_ite_ops = {
	.owner = THIS_MODULE,
	.id = I2C_HW_I_IIC,
	.algo_data = &iic_ite_data,
	.name = "ITE IIC adapter",
	};

	/* Called when the module is loaded. This function starts the
	* cascade of calls up through the hierarchy of i2c modules (i.e. up to the
	* algorithm layer and into to the core layer)
	*/
	static int __init iic_ite_init(void)
	{

	struct iic_ite *piic = &gpi;

	printk(KERN_INFO "Initialize ITE IIC adapter module\n");
	if (base == 0)
	piic->iic_base = DEFAULT_BASE;
	else
	piic->iic_base = base;

	if (irq == 0)
	piic->iic_irq = DEFAULT_IRQ;
	else
	piic->iic_irq = irq;

	if (clock == 0)
	piic->iic_clock = DEFAULT_CLOCK;
	else
	piic->iic_clock = clock;

	if (own == 0)
	piic->iic_own = DEFAULT_OWN;
	else
	piic->iic_own = own;

	iic_ite_data.data = (void *)piic;
	init_waitqueue_head(&iic_wait);
	spin_lock_init(&lock);
	if (iic_hw_resrc_init() == 0) {
	if (i2c_iic_add_bus(&iic_ite_ops) < 0)
	return -ENODEV;
	} else {
	return -ENODEV;
	}
	printk(KERN_INFO " found device at %#x irq %d.\n",
	piic->iic_base, piic->iic_irq);
	return 0;
	}


	static void iic_ite_exit(void)
	{
	i2c_iic_del_bus(&iic_ite_ops);
	iic_ite_release();
	}

	/* If modules is NOT defined when this file is compiled, then the MODULE_*
	* macros will resolve to nothing
	*/
	MODULE_AUTHOR("MontaVista Software <www.mvista.com>");
	MODULE_DESCRIPTION("I2C-Bus adapter routines for ITE IIC bus adapter");
	MODULE_LICENSE("GPL");

	module_param(base, int, 0);
	module_param(irq, int, 0);
	module_param(clock, int, 0);
	module_param(own, int, 0);


	/* Called when module is loaded or when kernel is initialized.
	* If MODULES is defined when this file is compiled, then this function will
	* resolve to init_module (the function called when insmod is invoked for a
	* module). Otherwise, this function is called early in the boot, when the
	* kernel is intialized. Check out /include/init.h to see how this works.
	*/
	module_init(iic_ite_init);

	/* Resolves to module_cleanup when MODULES is defined. */
	module_exit(iic_ite_exit);