526 lines
12 KiB
C
Executable File
526 lines
12 KiB
C
Executable File
/* ------------------------------------------------------------------------- */
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/* i2c-iop3xx.c i2c driver algorithms for Intel XScale IOP3xx & IXP46x */
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/* ------------------------------------------------------------------------- */
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/* Copyright (C) 2003 Peter Milne, D-TACQ Solutions Ltd
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* <Peter dot Milne at D hyphen TACQ dot com>
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*
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* With acknowledgements to i2c-algo-ibm_ocp.c by
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* Ian DaSilva, MontaVista Software, Inc. idasilva@mvista.com
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*
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* And i2c-algo-pcf.c, which was created by Simon G. Vogl and Hans Berglund:
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*
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* Copyright (C) 1995-1997 Simon G. Vogl, 1998-2000 Hans Berglund
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*
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* And which acknowledged Kyösti Mälkki <kmalkki@cc.hut.fi>,
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* Frodo Looijaard <frodol@dds.nl>, Martin Bailey<mbailey@littlefeet-inc.com>
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*
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* Major cleanup by Deepak Saxena <dsaxena@plexity.net>, 01/2005:
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*
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* - Use driver model to pass per-chip info instead of hardcoding and #ifdefs
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* - Use ioremap/__raw_readl/__raw_writel instead of direct dereference
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* - Make it work with IXP46x chips
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* - Cleanup function names, coding style, etc
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*
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* - writing to slave address causes latchup on iop331.
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* fix: driver refuses to address self.
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*
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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, version 2.
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*/
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#include <linux/interrupt.h>
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#include <linux/kernel.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/errno.h>
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#include <linux/platform_device.h>
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#include <linux/i2c.h>
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#include <linux/io.h>
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#include <linux/gpio.h>
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#include "i2c-iop3xx.h"
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/* global unit counter */
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static int i2c_id;
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static inline unsigned char
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iic_cook_addr(struct i2c_msg *msg)
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{
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unsigned char addr;
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addr = i2c_8bit_addr_from_msg(msg);
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return addr;
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}
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static void
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iop3xx_i2c_reset(struct i2c_algo_iop3xx_data *iop3xx_adap)
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{
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/* Follows devman 9.3 */
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__raw_writel(IOP3XX_ICR_UNIT_RESET, iop3xx_adap->ioaddr + CR_OFFSET);
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__raw_writel(IOP3XX_ISR_CLEARBITS, iop3xx_adap->ioaddr + SR_OFFSET);
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__raw_writel(0, iop3xx_adap->ioaddr + CR_OFFSET);
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}
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static void
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iop3xx_i2c_enable(struct i2c_algo_iop3xx_data *iop3xx_adap)
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{
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u32 cr = IOP3XX_ICR_GCD | IOP3XX_ICR_SCLEN | IOP3XX_ICR_UE;
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/*
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* Every time unit enable is asserted, GPOD needs to be cleared
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* on IOP3XX to avoid data corruption on the bus.
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*/
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#if defined(CONFIG_ARCH_IOP32X) || defined(CONFIG_ARCH_IOP33X)
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if (iop3xx_adap->id == 0) {
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gpio_set_value(7, 0);
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gpio_set_value(6, 0);
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} else {
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gpio_set_value(5, 0);
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gpio_set_value(4, 0);
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}
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#endif
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/* NB SR bits not same position as CR IE bits :-( */
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iop3xx_adap->SR_enabled =
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IOP3XX_ISR_ALD | IOP3XX_ISR_BERRD |
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IOP3XX_ISR_RXFULL | IOP3XX_ISR_TXEMPTY;
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cr |= IOP3XX_ICR_ALD_IE | IOP3XX_ICR_BERR_IE |
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IOP3XX_ICR_RXFULL_IE | IOP3XX_ICR_TXEMPTY_IE;
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__raw_writel(cr, iop3xx_adap->ioaddr + CR_OFFSET);
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}
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static void
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iop3xx_i2c_transaction_cleanup(struct i2c_algo_iop3xx_data *iop3xx_adap)
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{
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unsigned long cr = __raw_readl(iop3xx_adap->ioaddr + CR_OFFSET);
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cr &= ~(IOP3XX_ICR_MSTART | IOP3XX_ICR_TBYTE |
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IOP3XX_ICR_MSTOP | IOP3XX_ICR_SCLEN);
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__raw_writel(cr, iop3xx_adap->ioaddr + CR_OFFSET);
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}
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/*
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* NB: the handler has to clear the source of the interrupt!
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* Then it passes the SR flags of interest to BH via adap data
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*/
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static irqreturn_t
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iop3xx_i2c_irq_handler(int this_irq, void *dev_id)
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{
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struct i2c_algo_iop3xx_data *iop3xx_adap = dev_id;
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u32 sr = __raw_readl(iop3xx_adap->ioaddr + SR_OFFSET);
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if ((sr &= iop3xx_adap->SR_enabled)) {
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__raw_writel(sr, iop3xx_adap->ioaddr + SR_OFFSET);
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iop3xx_adap->SR_received |= sr;
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wake_up_interruptible(&iop3xx_adap->waitq);
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}
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return IRQ_HANDLED;
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}
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/* check all error conditions, clear them , report most important */
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static int
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iop3xx_i2c_error(u32 sr)
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{
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int rc = 0;
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if ((sr & IOP3XX_ISR_BERRD)) {
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if ( !rc ) rc = -I2C_ERR_BERR;
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}
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if ((sr & IOP3XX_ISR_ALD)) {
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if ( !rc ) rc = -I2C_ERR_ALD;
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}
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return rc;
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}
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static inline u32
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iop3xx_i2c_get_srstat(struct i2c_algo_iop3xx_data *iop3xx_adap)
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{
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unsigned long flags;
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u32 sr;
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spin_lock_irqsave(&iop3xx_adap->lock, flags);
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sr = iop3xx_adap->SR_received;
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iop3xx_adap->SR_received = 0;
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spin_unlock_irqrestore(&iop3xx_adap->lock, flags);
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return sr;
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}
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/*
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* sleep until interrupted, then recover and analyse the SR
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* saved by handler
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*/
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typedef int (* compare_func)(unsigned test, unsigned mask);
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/* returns 1 on correct comparison */
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static int
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iop3xx_i2c_wait_event(struct i2c_algo_iop3xx_data *iop3xx_adap,
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unsigned flags, unsigned* status,
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compare_func compare)
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{
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unsigned sr = 0;
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int interrupted;
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int done;
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int rc = 0;
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do {
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interrupted = wait_event_interruptible_timeout (
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iop3xx_adap->waitq,
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(done = compare( sr = iop3xx_i2c_get_srstat(iop3xx_adap) ,flags )),
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1 * HZ
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);
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if ((rc = iop3xx_i2c_error(sr)) < 0) {
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*status = sr;
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return rc;
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} else if (!interrupted) {
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*status = sr;
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return -ETIMEDOUT;
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}
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} while(!done);
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*status = sr;
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return 0;
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}
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/*
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* Concrete compare_funcs
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*/
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static int
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all_bits_clear(unsigned test, unsigned mask)
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{
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return (test & mask) == 0;
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}
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static int
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any_bits_set(unsigned test, unsigned mask)
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{
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return (test & mask) != 0;
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}
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static int
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iop3xx_i2c_wait_tx_done(struct i2c_algo_iop3xx_data *iop3xx_adap, int *status)
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{
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return iop3xx_i2c_wait_event(
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iop3xx_adap,
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IOP3XX_ISR_TXEMPTY | IOP3XX_ISR_ALD | IOP3XX_ISR_BERRD,
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status, any_bits_set);
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}
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static int
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iop3xx_i2c_wait_rx_done(struct i2c_algo_iop3xx_data *iop3xx_adap, int *status)
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{
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return iop3xx_i2c_wait_event(
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iop3xx_adap,
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IOP3XX_ISR_RXFULL | IOP3XX_ISR_ALD | IOP3XX_ISR_BERRD,
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status, any_bits_set);
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}
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static int
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iop3xx_i2c_wait_idle(struct i2c_algo_iop3xx_data *iop3xx_adap, int *status)
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{
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return iop3xx_i2c_wait_event(
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iop3xx_adap, IOP3XX_ISR_UNITBUSY, status, all_bits_clear);
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}
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static int
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iop3xx_i2c_send_target_addr(struct i2c_algo_iop3xx_data *iop3xx_adap,
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struct i2c_msg* msg)
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{
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unsigned long cr = __raw_readl(iop3xx_adap->ioaddr + CR_OFFSET);
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int status;
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int rc;
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/* avoid writing to my slave address (hangs on 80331),
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* forbidden in Intel developer manual
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*/
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if (msg->addr == MYSAR) {
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return -EBUSY;
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}
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__raw_writel(iic_cook_addr(msg), iop3xx_adap->ioaddr + DBR_OFFSET);
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cr &= ~(IOP3XX_ICR_MSTOP | IOP3XX_ICR_NACK);
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cr |= IOP3XX_ICR_MSTART | IOP3XX_ICR_TBYTE;
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__raw_writel(cr, iop3xx_adap->ioaddr + CR_OFFSET);
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rc = iop3xx_i2c_wait_tx_done(iop3xx_adap, &status);
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return rc;
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}
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static int
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iop3xx_i2c_write_byte(struct i2c_algo_iop3xx_data *iop3xx_adap, char byte,
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int stop)
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{
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unsigned long cr = __raw_readl(iop3xx_adap->ioaddr + CR_OFFSET);
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int status;
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int rc = 0;
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__raw_writel(byte, iop3xx_adap->ioaddr + DBR_OFFSET);
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cr &= ~IOP3XX_ICR_MSTART;
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if (stop) {
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cr |= IOP3XX_ICR_MSTOP;
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} else {
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cr &= ~IOP3XX_ICR_MSTOP;
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}
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cr |= IOP3XX_ICR_TBYTE;
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__raw_writel(cr, iop3xx_adap->ioaddr + CR_OFFSET);
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rc = iop3xx_i2c_wait_tx_done(iop3xx_adap, &status);
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return rc;
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}
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static int
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iop3xx_i2c_read_byte(struct i2c_algo_iop3xx_data *iop3xx_adap, char* byte,
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int stop)
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{
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unsigned long cr = __raw_readl(iop3xx_adap->ioaddr + CR_OFFSET);
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int status;
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int rc = 0;
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cr &= ~IOP3XX_ICR_MSTART;
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if (stop) {
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cr |= IOP3XX_ICR_MSTOP | IOP3XX_ICR_NACK;
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} else {
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cr &= ~(IOP3XX_ICR_MSTOP | IOP3XX_ICR_NACK);
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}
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cr |= IOP3XX_ICR_TBYTE;
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__raw_writel(cr, iop3xx_adap->ioaddr + CR_OFFSET);
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rc = iop3xx_i2c_wait_rx_done(iop3xx_adap, &status);
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*byte = __raw_readl(iop3xx_adap->ioaddr + DBR_OFFSET);
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return rc;
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}
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static int
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iop3xx_i2c_writebytes(struct i2c_adapter *i2c_adap, const char *buf, int count)
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{
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struct i2c_algo_iop3xx_data *iop3xx_adap = i2c_adap->algo_data;
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int ii;
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int rc = 0;
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for (ii = 0; rc == 0 && ii != count; ++ii)
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rc = iop3xx_i2c_write_byte(iop3xx_adap, buf[ii], ii==count-1);
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return rc;
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}
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static int
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iop3xx_i2c_readbytes(struct i2c_adapter *i2c_adap, char *buf, int count)
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{
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struct i2c_algo_iop3xx_data *iop3xx_adap = i2c_adap->algo_data;
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int ii;
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int rc = 0;
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for (ii = 0; rc == 0 && ii != count; ++ii)
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rc = iop3xx_i2c_read_byte(iop3xx_adap, &buf[ii], ii==count-1);
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return rc;
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}
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/*
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* Description: This function implements combined transactions. Combined
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* transactions consist of combinations of reading and writing blocks of data.
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* FROM THE SAME ADDRESS
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* Each transfer (i.e. a read or a write) is separated by a repeated start
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* condition.
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*/
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static int
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iop3xx_i2c_handle_msg(struct i2c_adapter *i2c_adap, struct i2c_msg* pmsg)
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{
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struct i2c_algo_iop3xx_data *iop3xx_adap = i2c_adap->algo_data;
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int rc;
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rc = iop3xx_i2c_send_target_addr(iop3xx_adap, pmsg);
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if (rc < 0) {
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return rc;
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}
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if ((pmsg->flags&I2C_M_RD)) {
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return iop3xx_i2c_readbytes(i2c_adap, pmsg->buf, pmsg->len);
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} else {
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return iop3xx_i2c_writebytes(i2c_adap, pmsg->buf, pmsg->len);
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}
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}
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/*
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* master_xfer() - main read/write entry
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*/
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static int
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iop3xx_i2c_master_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs,
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int num)
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{
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struct i2c_algo_iop3xx_data *iop3xx_adap = i2c_adap->algo_data;
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int im = 0;
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int ret = 0;
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int status;
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iop3xx_i2c_wait_idle(iop3xx_adap, &status);
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iop3xx_i2c_reset(iop3xx_adap);
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iop3xx_i2c_enable(iop3xx_adap);
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for (im = 0; ret == 0 && im != num; im++) {
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ret = iop3xx_i2c_handle_msg(i2c_adap, &msgs[im]);
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}
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iop3xx_i2c_transaction_cleanup(iop3xx_adap);
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if(ret)
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return ret;
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return im;
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}
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static u32
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iop3xx_i2c_func(struct i2c_adapter *adap)
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{
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return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
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}
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static const struct i2c_algorithm iop3xx_i2c_algo = {
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.master_xfer = iop3xx_i2c_master_xfer,
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.functionality = iop3xx_i2c_func,
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};
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static int
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iop3xx_i2c_remove(struct platform_device *pdev)
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{
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struct i2c_adapter *padapter = platform_get_drvdata(pdev);
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struct i2c_algo_iop3xx_data *adapter_data =
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(struct i2c_algo_iop3xx_data *)padapter->algo_data;
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struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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unsigned long cr = __raw_readl(adapter_data->ioaddr + CR_OFFSET);
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/*
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* Disable the actual HW unit
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*/
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cr &= ~(IOP3XX_ICR_ALD_IE | IOP3XX_ICR_BERR_IE |
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IOP3XX_ICR_RXFULL_IE | IOP3XX_ICR_TXEMPTY_IE);
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__raw_writel(cr, adapter_data->ioaddr + CR_OFFSET);
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iounmap(adapter_data->ioaddr);
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release_mem_region(res->start, IOP3XX_I2C_IO_SIZE);
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kfree(adapter_data);
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kfree(padapter);
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return 0;
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}
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static int
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iop3xx_i2c_probe(struct platform_device *pdev)
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{
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struct resource *res;
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int ret, irq;
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struct i2c_adapter *new_adapter;
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struct i2c_algo_iop3xx_data *adapter_data;
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new_adapter = kzalloc(sizeof(struct i2c_adapter), GFP_KERNEL);
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if (!new_adapter) {
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ret = -ENOMEM;
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goto out;
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}
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adapter_data = kzalloc(sizeof(struct i2c_algo_iop3xx_data), GFP_KERNEL);
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if (!adapter_data) {
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ret = -ENOMEM;
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goto free_adapter;
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}
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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if (!res) {
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ret = -ENODEV;
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goto free_both;
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}
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if (!request_mem_region(res->start, IOP3XX_I2C_IO_SIZE, pdev->name)) {
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ret = -EBUSY;
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goto free_both;
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}
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/* set the adapter enumeration # */
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adapter_data->id = i2c_id++;
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adapter_data->ioaddr = ioremap(res->start, IOP3XX_I2C_IO_SIZE);
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if (!adapter_data->ioaddr) {
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ret = -ENOMEM;
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goto release_region;
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}
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irq = platform_get_irq(pdev, 0);
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if (irq < 0) {
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ret = -ENXIO;
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goto unmap;
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}
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ret = request_irq(irq, iop3xx_i2c_irq_handler, 0,
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pdev->name, adapter_data);
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if (ret) {
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ret = -EIO;
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goto unmap;
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}
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memcpy(new_adapter->name, pdev->name, strlen(pdev->name));
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new_adapter->owner = THIS_MODULE;
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new_adapter->class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
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new_adapter->dev.parent = &pdev->dev;
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new_adapter->nr = pdev->id;
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/*
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* Default values...should these come in from board code?
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*/
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new_adapter->timeout = HZ;
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new_adapter->algo = &iop3xx_i2c_algo;
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init_waitqueue_head(&adapter_data->waitq);
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spin_lock_init(&adapter_data->lock);
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iop3xx_i2c_reset(adapter_data);
|
|
iop3xx_i2c_enable(adapter_data);
|
|
|
|
platform_set_drvdata(pdev, new_adapter);
|
|
new_adapter->algo_data = adapter_data;
|
|
|
|
i2c_add_numbered_adapter(new_adapter);
|
|
|
|
return 0;
|
|
|
|
unmap:
|
|
iounmap(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 = {
|
|
.name = "IOP3xx-I2C",
|
|
},
|
|
};
|
|
|
|
module_platform_driver(iop3xx_i2c_driver);
|
|
|
|
MODULE_AUTHOR("D-TACQ Solutions Ltd <www.d-tacq.com>");
|
|
MODULE_DESCRIPTION("IOP3xx iic algorithm and driver");
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_ALIAS("platform:IOP3xx-I2C");
|