path: root/drivers/i2c/busses/i2c-pxa.c

/*
 *  i2c_adap_pxa.c
 *
 *  I2C adapter for the PXA I2C bus access.
 *
 *  Copyright (C) 2002 Intrinsyc Software Inc.
 *  Copyright (C) 2004-2005 Deep Blue Solutions Ltd.
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2 as
 *  published by the Free Software Foundation.
 *
 *  History:
 *    Apr 2002: Initial version [CS]
 *    Jun 2002: Properly seperated algo/adap [FB]
 *    Jan 2003: Fixed several bugs concerning interrupt handling [Kai-Uwe Bloem]
 *    Jan 2003: added limited signal handling [Kai-Uwe Bloem]
 *    Sep 2004: Major rework to ensure efficient bus handling [RMK]
 *    Dec 2004: Added support for PXA27x and slave device probing [Liam Girdwood]
 *    Feb 2005: Rework slave mode handling [RMK]
 */
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/i2c-id.h>
#include <linux/init.h>
#include <linux/time.h>
#include <linux/sched.h>
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/i2c-pxa.h>
#include <linux/platform_device.h>
#include <linux/err.h>
#include <linux/clk.h>

#include <asm/hardware.h>
#include <asm/irq.h>
#include <asm/io.h>
#include <asm/arch/i2c.h>
#include <asm/arch/pxa-regs.h>
#include <asm/arch/pxa2xx-gpio.h>

struct pxa_i2c {
	spinlock_t		lock;
	wait_queue_head_t	wait;
	struct i2c_msg		*msg;
	unsigned int		msg_num;
	unsigned int		msg_idx;
	unsigned int		msg_ptr;
	unsigned int		slave_addr;

	struct i2c_adapter	adap;
	struct clk		*clk;
#ifdef CONFIG_I2C_PXA_SLAVE
	struct i2c_slave_client *slave;
#endif

	unsigned int		irqlogidx;
	u32			isrlog[32];
	u32			icrlog[32];

	void __iomem		*reg_base;

	unsigned long		iobase;
	unsigned long		iosize;

	int			irq;
	int			use_pio;
};

#define _IBMR(i2c)	((i2c)->reg_base + 0)
#define _IDBR(i2c)	((i2c)->reg_base + 8)
#define _ICR(i2c)	((i2c)->reg_base + 0x10)
#define _ISR(i2c)	((i2c)->reg_base + 0x18)
#define _ISAR(i2c)	((i2c)->reg_base + 0x20)

/*
 * I2C Slave mode address
 */
#define I2C_PXA_SLAVE_ADDR      0x1

#ifdef DEBUG

struct bits {
	u32	mask;
	const char *set;
	const char *unset;
};
#define PXA_BIT(m, s, u)	{ .mask = m, .set = s, .unset = u }

static inline void
decode_bits(const char *prefix, const struct bits *bits, int num, u32 val)
{
	printk("%s %08x: ", prefix, val);
	while (num--) {
		const char *str = val & bits->mask ? bits->set : bits->unset;
		if (str)
			printk("%s ", str);
		bits++;
	}
}

static const struct bits isr_bits[] = {
	PXA_BIT(ISR_RWM,	"RX",		"TX"),
	PXA_BIT(ISR_ACKNAK,	"NAK",		"ACK"),
	PXA_BIT(ISR_UB,		"Bsy",		"Rdy"),
	PXA_BIT(ISR_IBB,	"BusBsy",	"BusRdy"),
	PXA_BIT(ISR_SSD,	"SlaveStop",	NULL),
	PXA_BIT(ISR_ALD,	"ALD",		NULL),
	PXA_BIT(ISR_ITE,	"TxEmpty",	NULL),
	PXA_BIT(ISR_IRF,	"RxFull",	NULL),
	PXA_BIT(ISR_GCAD,	"GenCall",	NULL),
	PXA_BIT(ISR_SAD,	"SlaveAddr",	NULL),
	PXA_BIT(ISR_BED,	"BusErr",	NULL),
};

static void decode_ISR(unsigned int val)
{
	decode_bits(KERN_DEBUG "ISR", isr_bits, ARRAY_SIZE(isr_bits), val);
	printk("\n");
}

static const struct bits icr_bits[] = {
	PXA_BIT(ICR_START,  "START",	NULL),
	PXA_BIT(ICR_STOP,   "STOP",	NULL),
	PXA_BIT(ICR_ACKNAK, "ACKNAK",	NULL),
	PXA_BIT(ICR_TB,     "TB",	NULL),
	PXA_BIT(ICR_MA,     "MA",	NULL),
	PXA_BIT(ICR_SCLE,   "SCLE",	"scle"),
	PXA_BIT(