[net-next-2.6.git] / drivers / i2c / busses / i2c-iop3xx.c

/* ------------------------------------------------------------------------- */
/* i2c-iop3xx.c i2c driver algorithms for Intel XScale IOP3xx & IXP46x       */
/* ------------------------------------------------------------------------- */
/* Copyright (C) 2003 Peter Milne, D-TACQ Solutions Ltd
 *                    <Peter dot Milne at D hyphen TACQ dot com>
 *
 * With acknowledgements to i2c-algo-ibm_ocp.c by 
 * Ian DaSilva, MontaVista Software, Inc. idasilva@mvista.com
 *
 * And i2c-algo-pcf.c, which was created by Simon G. Vogl and Hans Berglund:
 *
 * Copyright (C) 1995-1997 Simon G. Vogl, 1998-2000 Hans Berglund
 *  
 * And which acknowledged Kyösti Mälkki <kmalkki@cc.hut.fi>,
 * Frodo Looijaard <frodol@dds.nl>, Martin Bailey<mbailey@littlefeet-inc.com>
 *
 * Major cleanup by Deepak Saxena <dsaxena@plexity.net>, 01/2005:
 *
 * - Use driver model to pass per-chip info instead of hardcoding and #ifdefs
 * - Use ioremap/__raw_readl/__raw_writel instead of direct dereference
 * - Make it work with IXP46x chips
 * - Cleanup function names, coding style, etc
 *
 * - writing to slave address causes latchup on iop331.
 *	fix: driver refuses to address self.
 *
 * 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, version 2.
 */

#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/platform_device.h>
#include <linux/i2c.h>

#include <asm/io.h>

#include "i2c-iop3xx.h"

/* global unit counter */
static int i2c_id;

static inline unsigned char 
iic_cook_addr(struct i2c_msg *msg) 
{
	unsigned char addr;

	addr = (msg->addr << 1);

	if (msg->flags & I2C_M_RD)
		addr |= 1;

	/*
	 * Read or Write?
	 */
	if (msg->flags & I2C_M_REV_DIR_ADDR)
		addr ^= 1;

	return addr;   
}

static void 
iop3xx_i2c_reset(struct i2c_algo_iop3xx_data *iop3xx_adap)
{
	/* Follows devman 9.3 */
	__raw_writel(IOP3XX_ICR_UNIT_RESET, iop3xx_adap->ioaddr + CR_OFFSET);
	__raw_writel(IOP3XX_ISR_CLEARBITS, iop3xx_adap->ioaddr + SR_OFFSET);
	__raw_writel(0, iop3xx_adap->ioaddr + CR_OFFSET);
} 

static void 
iop3xx_i2c_enable(struct i2c_algo_iop3xx_data *iop3xx_adap)
{
	u32 cr = IOP3XX_ICR_GCD | IOP3XX_ICR_SCLEN | IOP3XX_ICR_UE;

	/* 
	 * Every time unit enable is asserted, GPOD needs to be cleared
	 * on IOP3XX to avoid data corruption on the bus.
	 */
#ifdef CONFIG_PLAT_IOP
	if (iop3xx_adap->id == 0) {
		gpio_line_set(IOP3XX_GPIO_LINE(7), GPIO_LOW);
		gpio_line_set(IOP3XX_GPIO_LINE(6), GPIO_LOW);
	} else {
		gpio_line_set(IOP3XX_GPIO_LINE(5), GPIO_LOW);
		gpio_line_set(IOP3XX_GPIO_LINE(4), GPIO_LOW);
	}
#endif
	/* NB SR bits not same position as CR IE bits :-( */
	iop3xx_adap->SR_enabled = 
		IOP3XX_ISR_ALD | IOP3XX_ISR_BERRD |
		IOP3XX_ISR_RXFULL | IOP3XX_ISR_TXEMPTY;

	cr |= IOP3XX_ICR_ALD_IE | IOP3XX_ICR_BERR_IE |
		IOP3XX_ICR_RXFULL_IE | IOP3XX_ICR_TXEMPTY_IE;

	__raw_writel(cr, iop3xx_adap->ioaddr + CR_OFFSET);
}

static void 
iop3xx_i2c_transaction_cleanup(struct i2c_algo_iop3xx_data *iop3xx_adap)
{
	unsigned long cr = __raw_readl(iop3xx_adap->ioaddr + CR_OFFSET);
	
	cr &= ~(IOP3XX_ICR_MSTART | IOP3XX_ICR_TBYTE | 
		IOP3XX_ICR_MSTOP | IOP3XX_ICR_SCLEN);

	__raw_writel(cr, iop3xx_adap->ioaddr + CR_OFFSET);
}

/* 
 * NB: the handler has to clear the source of the interrupt! 
 * Then it passes the SR flags of interest to BH via adap data
 */
static irqreturn_t 
iop3xx_i2c_irq_handler(int this_irq, void *dev_id) 
{
	struct i2c_algo_iop3xx_data *iop3xx_adap = dev_id;
	u32 sr = __raw_readl(iop3xx_adap->ioaddr + SR_OFFSET);

	if ((sr &= iop3xx_adap->SR_enabled)) {
		__raw_writel(sr, iop3xx_adap->ioaddr + SR_OFFSET);
		iop3xx_adap->SR_received |= sr;
		wake_up_interruptible(&iop3xx_adap->waitq);
	}
	return IRQ_HANDLED;
}

/* check all error conditions, clear them , report most important */
static int 
iop3xx_i2c_error(u32 sr)
{
	int rc = 0;

	if ((sr & IOP3XX_ISR_BERRD)) {
		if ( !rc ) rc = -I2C_ERR_BERR;
	}
	if ((sr & IOP3XX_ISR_ALD)) {
		if ( !rc ) rc = -I2C_ERR_ALD;		
	}
	return rc;	
}

static inline u32 
iop3xx_i2c_get_srstat(struct i2c_algo_iop3xx_data *iop3xx_adap)
{
	unsigned long flags;
	u32 sr;

	spin_lock_irqsave(&iop3xx_adap->lock, flags);
	sr = iop3xx_adap->SR_received;
	iop3xx_adap->SR_received = 0;
	spin_unlock_irqrestore(&iop3xx_adap->lock, flags);

	return sr;
}

/*
 * sleep until interrupted, then recover and analyse the SR
 * saved by handler
 */
typedef int (* compare_func)(unsigned test, unsigned mask);
/* returns 1 on correct comparison */

static int 
iop3xx_i2c_wait_event(struct i2c_algo_iop3xx_data *iop3xx_adap, 
			  unsigned flags, unsigned* status,
			  compare_func compare)
{
	unsigned sr = 0;
	int interrupted;
	int done;
	int rc = 0;

	do {
		interrupted = wait_event_interruptible_timeout (
			iop3xx_adap->waitq,
			(done = compare( sr = iop3xx_i2c_get_srstat(iop3xx_adap) ,flags )),
			1 * HZ;
			);
		if ((rc = iop3xx_i2c_error(sr)) < 0) {
			*status = sr;
			return rc;
		} else if (!interrupted) {
			*status = sr;
			return -ETIMEDOUT;
		}
	} while(!done);

	*status = sr;

	return 0;
}

/*
 * Concrete compare_funcs 
 */
static int 
all_bits_clear(unsigned test, unsigned mask)
{
	return (test & mask) == 0;
}

static int 
any_bits_set(unsigned test, unsigned mask)
{
	return (test & mask) != 0;
}

static int 
iop3xx_i2c_wait_tx_done(struct i2c_algo_iop3xx_data *iop3xx_adap, int *status)
{
	return iop3xx_i2c_wait_event( 
		iop3xx_adap, 
	        IOP3XX_ISR_TXEMPTY | IOP3XX_ISR_ALD | IOP3XX_ISR_BERRD,
		status, any_bits_set);
}

static int 
iop3xx_i2c_wait_rx_done(struct i2c_algo_iop3xx_data *iop3xx_adap, int *status)
{
	return iop3xx_i2c_wait_event( 
		iop3xx_adap, 
		IOP3XX_ISR_RXFULL | IOP3XX_ISR_ALD | IOP3XX_ISR_BERRD,
		status,	any_bits_set);
}

static int 
iop3xx_i2c_wait_idle(struct i2c_algo_iop3xx_data *iop3xx_adap, int *status)
{
	return iop3xx_i2c_wait_event( 
		iop3xx_adap, IOP3XX_ISR_UNITBUSY, status, all_bits_clear);
}

static int 
iop3xx_i2c_send_target_addr(struct i2c_algo_iop3xx_data *iop3xx_adap, 
				struct i2c_msg* msg)
{
	unsigned long cr = __raw_readl(iop3xx_adap->ioaddr + CR_OFFSET);
	int status;
	int rc;

	/* avoid writing to my slave address (hangs on 80331),
	 * forbidden in Intel developer manual
	 */
	if (msg->addr == MYSAR) {
		return -EBUSY;
	}

	__raw_writel(iic_cook_addr(msg), iop3xx_adap->ioaddr + DBR_OFFSET);
	
	cr &= ~(IOP3XX_ICR_MSTOP | IOP3XX_ICR_NACK);
	cr |= IOP3XX_ICR_MSTART | IOP3XX_ICR_TBYTE;

	__raw_writel(cr, iop3xx_adap->ioaddr + CR_OFFSET);
	rc = iop3xx_i2c_wait_tx_done(iop3xx_adap, &status);

	return rc;
}

static int 
iop3xx_i2c_write_byte(struct i2c_algo_iop3xx_data *iop3xx_adap, char byte, 
				int stop)
{
	unsigned long cr = __raw_readl(iop3xx_adap->ioaddr + CR_OFFSET);
	int status;
	int rc = 0;

	__raw_writel(byte, iop3xx_adap->ioaddr + DBR_OFFSET);
	cr &= ~IOP3XX_ICR_MSTART;
	if (stop) {
		cr |= IOP3XX_ICR_MSTOP;
	} else {
		cr &= ~IOP3XX_ICR_MSTOP;
	}
	cr |= IOP3XX_ICR_TBYTE;
	__raw_writel(cr, iop3xx_adap->ioaddr + CR_OFFSET);
	rc = iop3xx_i2c_wait_tx_done(iop3xx_adap, &status);

	return rc;
} 

static int 
iop3xx_i2c_read_byte(struct i2c_algo_iop3xx_data *iop3xx_adap, char* byte, 
				int stop)
{
	unsigned long cr = __raw_readl(iop3xx_adap->ioaddr + CR_OFFSET);
	int status;
	int rc = 0;

	cr &= ~IOP3XX_ICR_MSTART;

	if (stop) {
		cr |= IOP3XX_ICR_MSTOP | IOP3XX_ICR_NACK;
	} else {
		cr &= ~(IOP3XX_ICR_MSTOP | IOP3XX_ICR_NACK);
	}
	cr |= IOP3XX_ICR_TBYTE;
	__raw_writel(cr, iop3xx_adap->ioaddr + CR_OFFSET);

	rc = iop3xx_i2c_wait_rx_done(iop3xx_adap, &status);

	*byte = __raw_readl(iop3xx_adap->ioaddr + DBR_OFFSET);

	return rc;
}

static int 
iop3xx_i2c_writebytes(struct i2c_adapter *i2c_adap, const char *buf, int count)
{
	struct i2c_algo_iop3xx_data *iop3xx_adap = i2c_adap->algo_data;
	int ii;
	int rc = 0;

	for (ii = 0; rc == 0 && ii != count; ++ii) 
		rc = iop3xx_i2c_write_byte(iop3xx_adap, buf[ii], ii==count-1);
	return rc;
}

static int 
iop3xx_i2c_readbytes(struct i2c_adapter *i2c_adap, char *buf, int count)
{
	struct i2c_algo_iop3xx_data *iop3xx_adap = i2c_adap->algo_data;
	int ii;
	int rc = 0;

	for (ii = 0; rc == 0 && ii != count; ++ii)
		rc = iop3xx_i2c_read_byte(iop3xx_adap, &buf[ii], ii==count-1);
	
	return rc;
}

/*
 * Description:  This function implements combined transactions.  Combined
 * transactions consist of combinations of reading and writing blocks of data.
 * FROM THE SAME ADDRESS
 * Each transfer (i.e. a read or a write) is separated by a repeated start
 * condition.
 */
static int 
iop3xx_i2c_handle_msg(struct i2c_adapter *i2c_adap, struct i2c_msg* pmsg) 
{
	struct i2c_algo_iop3xx_data *iop3xx_adap = i2c_adap->algo_data;
	int rc;

	rc = iop3xx_i2c_send_target_addr(iop3xx_adap, pmsg);
	if (rc < 0) {
		return rc;
	}

	if ((pmsg->flags&I2C_M_RD)) {
		return iop3xx_i2c_readbytes(i2c_adap, pmsg->buf, pmsg->len);
	} else {
		return iop3xx_i2c_writebytes(i2c_adap, pmsg->buf, pmsg->len);
	}
}

/*
 * master_xfer() - main read/write entry
 */
static int 
iop3xx_i2c_master_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs, 
				int num)
{
	struct i2c_algo_iop3xx_data *iop3xx_adap = i2c_adap->algo_data;
	int im = 0;
	int ret = 0;
	int status;

	iop3xx_i2c_wait_idle(iop3xx_adap, &status);
	iop3xx_i2c_reset(iop3xx_adap);
	iop3xx_i2c_enable(iop3xx_adap);

	for (im = 0; ret == 0 && im != num; im++) {
		ret = iop3xx_i2c_handle_msg(i2c_adap, &msgs[im]);
	}

	iop3xx_i2c_transaction_cleanup(iop3xx_adap);
	
	if(ret)
		return ret;

	return im;   
}

static int 
iop3xx_i2c_algo_control(struct i2c_adapter *adapter, unsigned int cmd,
			unsigned long arg)
{
	return 0;
}

static u32 
iop3xx_i2c_func(struct i2c_adapter *adap)
{
	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
}

static const struct i2c_algorithm iop3xx_i2c_algo = {
	.master_xfer	= iop3xx_i2c_master_xfer,
	.algo_control	= iop3xx_i2c_algo_control,
	.functionality	= iop3xx_i2c_func,
};

static int 
iop3xx_i2c_remove(struct platform_device *pdev)
{
	struct i2c_adapter *padapter = platform_get_drvdata(pdev);
	struct i2c_algo_iop3xx_data *adapter_data = 
		(struct i2c_algo_iop3xx_data *)padapter->algo_data;
	struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	unsigned long cr = __raw_readl(adapter_data->ioaddr + CR_OFFSET);

	/*
	 * Disable the actual HW unit
	 */
	cr &= ~(IOP3XX_ICR_ALD_IE | IOP3XX_ICR_BERR_IE |
		IOP3XX_ICR_RXFULL_IE | IOP3XX_ICR_TXEMPTY_IE);
	__raw_writel(cr, adapter_data->ioaddr + CR_OFFSET);

	iounmap((void __iomem*)adapter_data->ioaddr);
	release_mem_region(res->start, IOP3XX_I2C_IO_SIZE);
	kfree(adapter_data);
	kfree(padapter);

	platform_set_drvdata(pdev, NULL);

	return 0;
}

static int 
iop3xx_i2c_probe(struct platform_device *pdev)
{
	struct resource *res;
	int ret, irq;
	struct i2c_adapter *new_adapter;
	struct i2c_algo_iop3xx_data *adapter_data;

	new_adapter = kzalloc(sizeof(struct i2c_adapter), GFP_KERNEL);
	if (!new_adapter) {
		ret = -ENOMEM;
		goto out;
	}

	adapter_data = kzalloc(sizeof(struct i2c_algo_iop3xx_data), GFP_KERNEL);
	if (!adapter_data) {
		ret = -ENOMEM;
		goto free_adapter;
	}

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!res) {
		ret = -ENODEV;
		goto free_both;
	}

	if (!request_mem_region(res->start, IOP3XX_I2C_IO_SIZE, pdev->name)) {
		ret = -EBUSY;
		goto free_both;
	}

	/* set the adapter enumeration # */
	adapter_data->id = i2c_id++;

	adapter_data->ioaddr = (u32)ioremap(res->start, IOP3XX_I2C_IO_SIZE);
	if (!adapter_data->ioaddr) {
		ret = -ENOMEM;
		goto release_region;
	}

	irq = platform_get_irq(pdev, 0);
	if (irq < 0) {
		ret = -ENXIO;
		goto unmap;
	}
	ret = request_irq(irq, iop3xx_i2c_irq_handler, 0,
				pdev->name, adapter_data);

	if (ret) {
		ret = -EIO;
		goto unmap;
	}

	memcpy(new_adapter->name, pdev->name, strlen(pdev->name));
	new_adapter->id = I2C_HW_IOP3XX;
	new_adapter->owner = THIS_MODULE;
	new_adapter->dev.parent = &pdev->dev;

	/*
	 * Default values...should these come in from board code?
	 */
	new_adapter->timeout = 100;	
	new_adapter->retries = 3;
	new_adapter->algo = &iop3xx_i2c_algo;

	init_waitqueue_head(&adapter_data->waitq);
	spin_lock_init(&adapter_data->lock);

	iop3xx_i2c_reset(adapter_data);
	iop3xx_i2c_enable(adapter_data);

	platform_set_drvdata(pdev, new_adapter);
	new_adapter->algo_data = adapter_data;

	i2c_add_adapter(new_adapter);

	return 0;

unmap:
	iounmap((void __iomem*)adapter_data->ioaddr);

release_region:
	release_mem_region(res->start, IOP3XX_I2C_IO_SIZE);

free_both:
	kfree(adapter_data);

free_adapter:
	kfree(new_adapter);

out:
	return ret;
}


static struct platform_driver iop3xx_i2c_driver = {
	.probe		= iop3xx_i2c_probe,
	.remove		= iop3xx_i2c_remove,
	.driver		= {
		.owner	= THIS_MODULE,
		.name	= "IOP3xx-I2C",
	},
};

static int __init 
i2c_iop3xx_init (void)
{
	return platform_driver_register(&iop3xx_i2c_driver);
}

static void __exit 
i2c_iop3xx_exit (void)
{
	platform_driver_unregister(&iop3xx_i2c_driver);
	return;
}

module_init (i2c_iop3xx_init);
module_exit (i2c_iop3xx_exit);

MODULE_AUTHOR("D-TACQ Solutions Ltd <www.d-tacq.com>");
MODULE_DESCRIPTION("IOP3xx iic algorithm and driver");
MODULE_LICENSE("GPL");
Commit	Line	Data
1da177e4 LT	1	/* ------------------------------------------------------------------------- */
	2	/* i2c-iop3xx.c i2c driver algorithms for Intel XScale IOP3xx & IXP46x */
	3	/* ------------------------------------------------------------------------- */
	4	/* Copyright (C) 2003 Peter Milne, D-TACQ Solutions Ltd
	5	* <Peter dot Milne at D hyphen TACQ dot com>
	6	*
	7	* With acknowledgements to i2c-algo-ibm_ocp.c by
	8	* Ian DaSilva, MontaVista Software, Inc. idasilva@mvista.com
	9	*
	10	* And i2c-algo-pcf.c, which was created by Simon G. Vogl and Hans Berglund:
	11	*
	12	* Copyright (C) 1995-1997 Simon G. Vogl, 1998-2000 Hans Berglund
	13	*
fbd9a6d7	14	* And which acknowledged Kyösti Mälkki <kmalkki@cc.hut.fi>,
1da177e4 LT	15	* Frodo Looijaard <frodol@dds.nl>, Martin Bailey<mbailey@littlefeet-inc.com>
	16	*
	17	* Major cleanup by Deepak Saxena <dsaxena@plexity.net>, 01/2005:
	18	*
	19	* - Use driver model to pass per-chip info instead of hardcoding and #ifdefs
	20	* - Use ioremap/__raw_readl/__raw_writel instead of direct dereference
	21	* - Make it work with IXP46x chips
	22	* - Cleanup function names, coding style, etc
	23	*
39288e1a PM	24	* - writing to slave address causes latchup on iop331.
	25	* fix: driver refuses to address self.
	26	*
1da177e4 LT	27	* This program is free software; you can redistribute it and/or modify
	28	* it under the terms of the GNU General Public License as published by
	29	* the Free Software Foundation, version 2.
	30	*/
	31
1da177e4 LT	32	#include <linux/interrupt.h>
	33	#include <linux/kernel.h>
	34	#include <linux/module.h>
	35	#include <linux/delay.h>
	36	#include <linux/slab.h>
	37	#include <linux/init.h>
	38	#include <linux/errno.h>
d052d1be	39	#include <linux/platform_device.h>
1da177e4 LT	40	#include <linux/i2c.h>
	41
	42	#include <asm/io.h>
	43
	44	#include "i2c-iop3xx.h"
	45
	46	/* global unit counter */
60507095	47	static int i2c_id;
1da177e4 LT	48
	49	static inline unsigned char
	50	iic_cook_addr(struct i2c_msg *msg)
	51	{
	52	unsigned char addr;
	53
	54	addr = (msg->addr << 1);
	55
	56	if (msg->flags & I2C_M_RD)
	57	addr \|= 1;
	58
	59	/*
	60	* Read or Write?
	61	*/
	62	if (msg->flags & I2C_M_REV_DIR_ADDR)
	63	addr ^= 1;
	64
	65	return addr;
	66	}
	67
	68	static void
	69	iop3xx_i2c_reset(struct i2c_algo_iop3xx_data *iop3xx_adap)
	70	{
	71	/* Follows devman 9.3 */
	72	__raw_writel(IOP3XX_ICR_UNIT_RESET, iop3xx_adap->ioaddr + CR_OFFSET);
	73	__raw_writel(IOP3XX_ISR_CLEARBITS, iop3xx_adap->ioaddr + SR_OFFSET);
	74	__raw_writel(0, iop3xx_adap->ioaddr + CR_OFFSET);
	75	}
	76
1da177e4 LT	77	static void
	78	iop3xx_i2c_enable(struct i2c_algo_iop3xx_data *iop3xx_adap)
	79	{
	80	u32 cr = IOP3XX_ICR_GCD \| IOP3XX_ICR_SCLEN \| IOP3XX_ICR_UE;
	81
	82	/*
44bbe87e	83	* Every time unit enable is asserted, GPOD needs to be cleared
72edd84a	84	* on IOP3XX to avoid data corruption on the bus.
1da177e4	85	*/
72edd84a LB	86	#ifdef CONFIG_PLAT_IOP
	87	if (iop3xx_adap->id == 0) {
	88	gpio_line_set(IOP3XX_GPIO_LINE(7), GPIO_LOW);
	89	gpio_line_set(IOP3XX_GPIO_LINE(6), GPIO_LOW);
	90	} else {
	91	gpio_line_set(IOP3XX_GPIO_LINE(5), GPIO_LOW);
	92	gpio_line_set(IOP3XX_GPIO_LINE(4), GPIO_LOW);
	93	}
1da177e4 LT	94	#endif
	95	/* NB SR bits not same position as CR IE bits :-( */
	96	iop3xx_adap->SR_enabled =
	97	IOP3XX_ISR_ALD \| IOP3XX_ISR_BERRD \|
	98	IOP3XX_ISR_RXFULL \| IOP3XX_ISR_TXEMPTY;
	99
	100	cr \|= IOP3XX_ICR_ALD_IE \| IOP3XX_ICR_BERR_IE \|
	101	IOP3XX_ICR_RXFULL_IE \| IOP3XX_ICR_TXEMPTY_IE;
	102
	103	__raw_writel(cr, iop3xx_adap->ioaddr + CR_OFFSET);
	104	}
	105
	106	static void
	107	iop3xx_i2c_transaction_cleanup(struct i2c_algo_iop3xx_data *iop3xx_adap)
	108	{
	109	unsigned long cr = __raw_readl(iop3xx_adap->ioaddr + CR_OFFSET);
	110
	111	cr &= ~(IOP3XX_ICR_MSTART \| IOP3XX_ICR_TBYTE \|
	112	IOP3XX_ICR_MSTOP \| IOP3XX_ICR_SCLEN);
	113
	114	__raw_writel(cr, iop3xx_adap->ioaddr + CR_OFFSET);
	115	}
	116
	117	/*
	118	* NB: the handler has to clear the source of the interrupt!
	119	* Then it passes the SR flags of interest to BH via adap data
	120	*/
	121	static irqreturn_t
7d12e780	122	iop3xx_i2c_irq_handler(int this_irq, void *dev_id)
1da177e4 LT	123	{
	124	struct i2c_algo_iop3xx_data *iop3xx_adap = dev_id;
	125	u32 sr = __raw_readl(iop3xx_adap->ioaddr + SR_OFFSET);
	126
	127	if ((sr &= iop3xx_adap->SR_enabled)) {
	128	__raw_writel(sr, iop3xx_adap->ioaddr + SR_OFFSET);
	129	iop3xx_adap->SR_received \|= sr;
	130	wake_up_interruptible(&iop3xx_adap->waitq);
	131	}
	132	return IRQ_HANDLED;
	133	}
	134
	135	/* check all error conditions, clear them , report most important */
	136	static int
	137	iop3xx_i2c_error(u32 sr)
	138	{
	139	int rc = 0;
	140
	141	if ((sr & IOP3XX_ISR_BERRD)) {
	142	if ( !rc ) rc = -I2C_ERR_BERR;
	143	}
	144	if ((sr & IOP3XX_ISR_ALD)) {
	145	if ( !rc ) rc = -I2C_ERR_ALD;
	146	}
	147	return rc;
	148	}
	149
	150	static inline u32
	151	iop3xx_i2c_get_srstat(struct i2c_algo_iop3xx_data *iop3xx_adap)
	152	{
	153	unsigned long flags;
	154	u32 sr;
	155
	156	spin_lock_irqsave(&iop3xx_adap->lock, flags);
	157	sr = iop3xx_adap->SR_received;
	158	iop3xx_adap->SR_received = 0;
	159	spin_unlock_irqrestore(&iop3xx_adap->lock, flags);
	160
	161	return sr;
	162	}
	163
	164	/*
	165	* sleep until interrupted, then recover and analyse the SR
	166	* saved by handler
	167	*/
	168	typedef int (* compare_func)(unsigned test, unsigned mask);
	169	/* returns 1 on correct comparison */
	170
	171	static int
	172	iop3xx_i2c_wait_event(struct i2c_algo_iop3xx_data *iop3xx_adap,
	173	unsigned flags, unsigned* status,
	174	compare_func compare)
	175	{
	176	unsigned sr = 0;
	177	int interrupted;
	178	int done;
	179	int rc = 0;
	180
	181	do {
	182	interrupted = wait_event_interruptible_timeout (
	183	iop3xx_adap->waitq,
fbd9a6d7	184	(done = compare( sr = iop3xx_i2c_get_srstat(iop3xx_adap) ,flags )),
1da177e4 LT	185	1 * HZ;
	186	);
	187	if ((rc = iop3xx_i2c_error(sr)) < 0) {
	188	*status = sr;
	189	return rc;
	190	} else if (!interrupted) {
	191	*status = sr;
	192	return -ETIMEDOUT;
	193	}
	194	} while(!done);
	195
	196	*status = sr;
	197
	198	return 0;
	199	}
	200
	201	/*
	202	* Concrete compare_funcs
	203	*/
	204	static int
	205	all_bits_clear(unsigned test, unsigned mask)
	206	{
	207	return (test & mask) == 0;
	208	}
	209
	210	static int
	211	any_bits_set(unsigned test, unsigned mask)
	212	{
	213	return (test & mask) != 0;
	214	}
	215
	216	static int
	217	iop3xx_i2c_wait_tx_done(struct i2c_algo_iop3xx_data iop3xx_adap, int status)
	218	{
	219	return iop3xx_i2c_wait_event(
	220	iop3xx_adap,
	221	IOP3XX_ISR_TXEMPTY \| IOP3XX_ISR_ALD \| IOP3XX_ISR_BERRD,
	222	status, any_bits_set);
	223	}
	224
	225	static int
	226	iop3xx_i2c_wait_rx_done(struct i2c_algo_iop3xx_data iop3xx_adap, int status)
	227	{
	228	return iop3xx_i2c_wait_event(
	229	iop3xx_adap,
	230	IOP3XX_ISR_RXFULL \| IOP3XX_ISR_ALD \| IOP3XX_ISR_BERRD,
	231	status, any_bits_set);
	232	}
	233
	234	static int
	235	iop3xx_i2c_wait_idle(struct i2c_algo_iop3xx_data iop3xx_adap, int status)
	236	{
	237	return iop3xx_i2c_wait_event(
	238	iop3xx_adap, IOP3XX_ISR_UNITBUSY, status, all_bits_clear);
	239	}
	240
	241	static int
	242	iop3xx_i2c_send_target_addr(struct i2c_algo_iop3xx_data *iop3xx_adap,
	243	struct i2c_msg* msg)
	244	{
	245	unsigned long cr = __raw_readl(iop3xx_adap->ioaddr + CR_OFFSET);
	246	int status;
	247	int rc;
	248
39288e1a PM	249	/* avoid writing to my slave address (hangs on 80331),
	250	* forbidden in Intel developer manual
	251	*/
	252	if (msg->addr == MYSAR) {
	253	return -EBUSY;
	254	}
	255
1da177e4 LT	256	__raw_writel(iic_cook_addr(msg), iop3xx_adap->ioaddr + DBR_OFFSET);
	257
	258	cr &= ~(IOP3XX_ICR_MSTOP \| IOP3XX_ICR_NACK);
	259	cr \|= IOP3XX_ICR_MSTART \| IOP3XX_ICR_TBYTE;
	260
	261	__raw_writel(cr, iop3xx_adap->ioaddr + CR_OFFSET);
	262	rc = iop3xx_i2c_wait_tx_done(iop3xx_adap, &status);
	263
	264	return rc;
	265	}
	266
	267	static int
	268	iop3xx_i2c_write_byte(struct i2c_algo_iop3xx_data *iop3xx_adap, char byte,
	269	int stop)
	270	{
	271	unsigned long cr = __raw_readl(iop3xx_adap->ioaddr + CR_OFFSET);
	272	int status;
	273	int rc = 0;
	274
	275	__raw_writel(byte, iop3xx_adap->ioaddr + DBR_OFFSET);
	276	cr &= ~IOP3XX_ICR_MSTART;
	277	if (stop) {
	278	cr \|= IOP3XX_ICR_MSTOP;
	279	} else {
	280	cr &= ~IOP3XX_ICR_MSTOP;
	281	}
	282	cr \|= IOP3XX_ICR_TBYTE;
	283	__raw_writel(cr, iop3xx_adap->ioaddr + CR_OFFSET);
	284	rc = iop3xx_i2c_wait_tx_done(iop3xx_adap, &status);
	285
	286	return rc;
	287	}
	288
	289	static int
	290	iop3xx_i2c_read_byte(struct i2c_algo_iop3xx_data iop3xx_adap, char byte,
	291	int stop)
	292	{
	293	unsigned long cr = __raw_readl(iop3xx_adap->ioaddr + CR_OFFSET);
	294	int status;
	295	int rc = 0;
	296
	297	cr &= ~IOP3XX_ICR_MSTART;
	298
	299	if (stop) {
	300	cr \|= IOP3XX_ICR_MSTOP \| IOP3XX_ICR_NACK;
	301	} else {
	302	cr &= ~(IOP3XX_ICR_MSTOP \| IOP3XX_ICR_NACK);
	303	}
	304	cr \|= IOP3XX_ICR_TBYTE;
	305	__raw_writel(cr, iop3xx_adap->ioaddr + CR_OFFSET);
	306
	307	rc = iop3xx_i2c_wait_rx_done(iop3xx_adap, &status);
	308
	309	*byte = __raw_readl(iop3xx_adap->ioaddr + DBR_OFFSET);
	310
	311	return rc;
	312	}
	313
	314	static int
	315	iop3xx_i2c_writebytes(struct i2c_adapter i2c_adap, const char buf, int count)
	316	{
	317	struct i2c_algo_iop3xx_data *iop3xx_adap = i2c_adap->algo_data;
	318	int ii;
	319	int rc = 0;
320
321	for (ii = 0; rc == 0 && ii != count; ++ii)
322	rc = iop3xx_i2c_write_byte(iop3xx_adap, buf[ii], ii==count-1);
323	return rc;
324	}
325
326	static int
327	iop3xx_i2c_readbytes(struct i2c_adapter i2c_adap, char buf, int count)
328	{
329	struct i2c_algo_iop3xx_data *iop3xx_adap = i2c_adap->algo_data;
330	int ii;
331	int rc = 0;
332
333	for (ii = 0; rc == 0 && ii != count; ++ii)
334	rc = iop3xx_i2c_read_byte(iop3xx_adap, &buf[ii], ii==count-1);
335
336	return rc;
337	}
338
339	/*
340	* Description: This function implements combined transactions. Combined
341	* transactions consist of combinations of reading and writing blocks of data.
342	* FROM THE SAME ADDRESS
343	* Each transfer (i.e. a read or a write) is separated by a repeated start
344	* condition.
345	*/
346	static int
347	iop3xx_i2c_handle_msg(struct i2c_adapter i2c_adap, struct i2c_msg pmsg)
348	{
349	struct i2c_algo_iop3xx_data *iop3xx_adap = i2c_adap->algo_data;
350	int rc;
351
352	rc = iop3xx_i2c_send_target_addr(iop3xx_adap, pmsg);
353	if (rc < 0) {
354	return rc;
355	}
356
357	if ((pmsg->flags&I2C_M_RD)) {
358	return iop3xx_i2c_readbytes(i2c_adap, pmsg->buf, pmsg->len);
359	} else {
360	return iop3xx_i2c_writebytes(i2c_adap, pmsg->buf, pmsg->len);
361	}
362	}
363
364	/*
365	* master_xfer() - main read/write entry
366	*/
367	static int
368	iop3xx_i2c_master_xfer(struct i2c_adapter i2c_adap, struct i2c_msg msgs,
369	int num)
370	{
371	struct i2c_algo_iop3xx_data *iop3xx_adap = i2c_adap->algo_data;
372	int im = 0;
373	int ret = 0;
374	int status;
375
376	iop3xx_i2c_wait_idle(iop3xx_adap, &status);
377	iop3xx_i2c_reset(iop3xx_adap);
378	iop3xx_i2c_enable(iop3xx_adap);
379
380	for (im = 0; ret == 0 && im != num; im++) {
381	ret = iop3xx_i2c_handle_msg(i2c_adap, &msgs[im]);
382	}
383
384	iop3xx_i2c_transaction_cleanup(iop3xx_adap);
385
386	if(ret)
387	return ret;
388
389	return im;
390	}
391
392	static int
393	iop3xx_i2c_algo_control(struct i2c_adapter *adapter, unsigned int cmd,
394	unsigned long arg)
395	{
396	return 0;
397	}
398
399	static u32
400	iop3xx_i2c_func(struct i2c_adapter *adap)
401	{
402	return I2C_FUNC_I2C \| I2C_FUNC_SMBUS_EMUL;
403	}
404
8f9082c5	405	static const struct i2c_algorithm iop3xx_i2c_algo = {
1da177e4 LT	406	.master_xfer = iop3xx_i2c_master_xfer,
	407	.algo_control = iop3xx_i2c_algo_control,
	408	.functionality = iop3xx_i2c_func,
	409	};
	410
	411	static int
3ae5eaec	412	iop3xx_i2c_remove(struct platform_device *pdev)
1da177e4	413	{
3ae5eaec	414	struct i2c_adapter *padapter = platform_get_drvdata(pdev);
1da177e4 LT	415	struct i2c_algo_iop3xx_data *adapter_data =
	416	(struct i2c_algo_iop3xx_data *)padapter->algo_data;
	417	struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	418	unsigned long cr = __raw_readl(adapter_data->ioaddr + CR_OFFSET);
	419
	420	/*
	421	* Disable the actual HW unit
	422	*/
	423	cr &= ~(IOP3XX_ICR_ALD_IE \| IOP3XX_ICR_BERR_IE \|
	424	IOP3XX_ICR_RXFULL_IE \| IOP3XX_ICR_TXEMPTY_IE);
	425	__raw_writel(cr, adapter_data->ioaddr + CR_OFFSET);
	426
	427	iounmap((void __iomem*)adapter_data->ioaddr);
	428	release_mem_region(res->start, IOP3XX_I2C_IO_SIZE);
	429	kfree(adapter_data);
	430	kfree(padapter);
	431
3ae5eaec	432	platform_set_drvdata(pdev, NULL);
1da177e4 LT	433
	434	return 0;
	435	}
	436
	437	static int
3ae5eaec	438	iop3xx_i2c_probe(struct platform_device *pdev)
1da177e4	439	{
1da177e4	440	struct resource *res;
48944738	441	int ret, irq;
1da177e4 LT	442	struct i2c_adapter *new_adapter;
	443	struct i2c_algo_iop3xx_data *adapter_data;
	444
5263ebb5	445	new_adapter = kzalloc(sizeof(struct i2c_adapter), GFP_KERNEL);
1da177e4 LT	446	if (!new_adapter) {
	447	ret = -ENOMEM;
	448	goto out;
	449	}
1da177e4	450
5263ebb5	451	adapter_data = kzalloc(sizeof(struct i2c_algo_iop3xx_data), GFP_KERNEL);
1da177e4 LT	452	if (!adapter_data) {
	453	ret = -ENOMEM;
	454	goto free_adapter;
	455	}
1da177e4 LT	456
	457	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	458	if (!res) {
	459	ret = -ENODEV;
	460	goto free_both;
	461	}
	462
	463	if (!request_mem_region(res->start, IOP3XX_I2C_IO_SIZE, pdev->name)) {
	464	ret = -EBUSY;
	465	goto free_both;
	466	}
	467
	468	/* set the adapter enumeration # */
	469	adapter_data->id = i2c_id++;
	470
	471	adapter_data->ioaddr = (u32)ioremap(res->start, IOP3XX_I2C_IO_SIZE);
	472	if (!adapter_data->ioaddr) {
	473	ret = -ENOMEM;
	474	goto release_region;
	475	}
	476
48944738 DV	477	irq = platform_get_irq(pdev, 0);
	478	if (irq < 0) {
	479	ret = -ENXIO;
	480	goto unmap;
	481	}
	482	ret = request_irq(irq, iop3xx_i2c_irq_handler, 0,
1da177e4	483	pdev->name, adapter_data);
fbd9a6d7 DW	484
fbd9a6d7 DW	485	if (ret) {
1da177e4 LT	486	ret = -EIO;
	487	goto unmap;
	488	}
	489
	490	memcpy(new_adapter->name, pdev->name, strlen(pdev->name));
	491	new_adapter->id = I2C_HW_IOP3XX;
	492	new_adapter->owner = THIS_MODULE;
	493	new_adapter->dev.parent = &pdev->dev;
	494
	495	/*
	496	* Default values...should these come in from board code?
	497	*/
	498	new_adapter->timeout = 100;
	499	new_adapter->retries = 3;
	500	new_adapter->algo = &iop3xx_i2c_algo;
	501
	502	init_waitqueue_head(&adapter_data->waitq);
	503	spin_lock_init(&adapter_data->lock);
	504
	505	iop3xx_i2c_reset(adapter_data);
1da177e4 LT	506	iop3xx_i2c_enable(adapter_data);
1da177e4 LT	507
3ae5eaec	508	platform_set_drvdata(pdev, new_adapter);
1da177e4 LT	509	new_adapter->algo_data = adapter_data;
	510
	511	i2c_add_adapter(new_adapter);
	512
	513	return 0;
	514
	515	unmap:
	516	iounmap((void __iomem*)adapter_data->ioaddr);
	517
	518	release_region:
	519	release_mem_region(res->start, IOP3XX_I2C_IO_SIZE);
	520
	521	free_both:
	522	kfree(adapter_data);
	523
	524	free_adapter:
	525	kfree(new_adapter);
	526
	527	out:
	528	return ret;
	529	}
	530
	531
3ae5eaec	532	static struct platform_driver iop3xx_i2c_driver = {
1da177e4	533	.probe = iop3xx_i2c_probe,
3ae5eaec RK	534	.remove = iop3xx_i2c_remove,
	535	.driver = {
	536	.owner = THIS_MODULE,
	537	.name = "IOP3xx-I2C",
	538	},
1da177e4 LT	539	};
	540
	541	static int __init
	542	i2c_iop3xx_init (void)
	543	{
3ae5eaec	544	return platform_driver_register(&iop3xx_i2c_driver);
1da177e4 LT	545	}
	546
	547	static void __exit
	548	i2c_iop3xx_exit (void)
	549	{
3ae5eaec	550	platform_driver_unregister(&iop3xx_i2c_driver);
1da177e4 LT	551	return;
	552	}
	553
	554	module_init (i2c_iop3xx_init);
	555	module_exit (i2c_iop3xx_exit);
	556
	557	MODULE_AUTHOR("D-TACQ Solutions Ltd <www.d-tacq.com>");
	558	MODULE_DESCRIPTION("IOP3xx iic algorithm and driver");
	559	MODULE_LICENSE("GPL");