[deliverable/linux.git] / drivers / i2c / busses / i2c-omap.c

/*
 * TI OMAP I2C master mode driver
 *
 * Copyright (C) 2003 MontaVista Software, Inc.
 * Copyright (C) 2004 Texas Instruments.
 *
 * Updated to work with multiple I2C interfaces on 24xx by
 * Tony Lindgren <tony@atomide.com> and Imre Deak <imre.deak@nokia.com>
 * Copyright (C) 2005 Nokia Corporation
 *
 * Cleaned up by Juha Yrjölä <juha.yrjola@nokia.com>
 *
 * 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.
 */

#include <linux/module.h>
#include <linux/delay.h>
#include <linux/i2c.h>
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/completion.h>
#include <linux/platform_device.h>
#include <linux/clk.h>

#include <asm/io.h>

/* timeout waiting for the controller to respond */
#define OMAP_I2C_TIMEOUT (msecs_to_jiffies(1000))

#define OMAP_I2C_REV_REG		0x00
#define OMAP_I2C_IE_REG			0x04
#define OMAP_I2C_STAT_REG		0x08
#define OMAP_I2C_IV_REG			0x0c
#define OMAP_I2C_SYSS_REG		0x10
#define OMAP_I2C_BUF_REG		0x14
#define OMAP_I2C_CNT_REG		0x18
#define OMAP_I2C_DATA_REG		0x1c
#define OMAP_I2C_SYSC_REG		0x20
#define OMAP_I2C_CON_REG		0x24
#define OMAP_I2C_OA_REG			0x28
#define OMAP_I2C_SA_REG			0x2c
#define OMAP_I2C_PSC_REG		0x30
#define OMAP_I2C_SCLL_REG		0x34
#define OMAP_I2C_SCLH_REG		0x38
#define OMAP_I2C_SYSTEST_REG		0x3c

/* I2C Interrupt Enable Register (OMAP_I2C_IE): */
#define OMAP_I2C_IE_XRDY	(1 << 4)	/* TX data ready int enable */
#define OMAP_I2C_IE_RRDY	(1 << 3)	/* RX data ready int enable */
#define OMAP_I2C_IE_ARDY	(1 << 2)	/* Access ready int enable */
#define OMAP_I2C_IE_NACK	(1 << 1)	/* No ack interrupt enable */
#define OMAP_I2C_IE_AL		(1 << 0)	/* Arbitration lost int ena */

/* I2C Status Register (OMAP_I2C_STAT): */
#define OMAP_I2C_STAT_SBD	(1 << 15)	/* Single byte data */
#define OMAP_I2C_STAT_BB	(1 << 12)	/* Bus busy */
#define OMAP_I2C_STAT_ROVR	(1 << 11)	/* Receive overrun */
#define OMAP_I2C_STAT_XUDF	(1 << 10)	/* Transmit underflow */
#define OMAP_I2C_STAT_AAS	(1 << 9)	/* Address as slave */
#define OMAP_I2C_STAT_AD0	(1 << 8)	/* Address zero */
#define OMAP_I2C_STAT_XRDY	(1 << 4)	/* Transmit data ready */
#define OMAP_I2C_STAT_RRDY	(1 << 3)	/* Receive data ready */
#define OMAP_I2C_STAT_ARDY	(1 << 2)	/* Register access ready */
#define OMAP_I2C_STAT_NACK	(1 << 1)	/* No ack interrupt enable */
#define OMAP_I2C_STAT_AL	(1 << 0)	/* Arbitration lost int ena */

/* I2C Buffer Configuration Register (OMAP_I2C_BUF): */
#define OMAP_I2C_BUF_RDMA_EN	(1 << 15)	/* RX DMA channel enable */
#define OMAP_I2C_BUF_XDMA_EN	(1 << 7)	/* TX DMA channel enable */

/* I2C Configuration Register (OMAP_I2C_CON): */
#define OMAP_I2C_CON_EN		(1 << 15)	/* I2C module enable */
#define OMAP_I2C_CON_BE		(1 << 14)	/* Big endian mode */
#define OMAP_I2C_CON_STB	(1 << 11)	/* Start byte mode (master) */
#define OMAP_I2C_CON_MST	(1 << 10)	/* Master/slave mode */
#define OMAP_I2C_CON_TRX	(1 << 9)	/* TX/RX mode (master only) */
#define OMAP_I2C_CON_XA		(1 << 8)	/* Expand address */
#define OMAP_I2C_CON_RM		(1 << 2)	/* Repeat mode (master only) */
#define OMAP_I2C_CON_STP	(1 << 1)	/* Stop cond (master only) */
#define OMAP_I2C_CON_STT	(1 << 0)	/* Start condition (master) */

/* I2C System Test Register (OMAP_I2C_SYSTEST): */
#ifdef DEBUG
#define OMAP_I2C_SYSTEST_ST_EN		(1 << 15)	/* System test enable */
#define OMAP_I2C_SYSTEST_FREE		(1 << 14)	/* Free running mode */
#define OMAP_I2C_SYSTEST_TMODE_MASK	(3 << 12)	/* Test mode select */
#define OMAP_I2C_SYSTEST_TMODE_SHIFT	(12)		/* Test mode select */
#define OMAP_I2C_SYSTEST_SCL_I		(1 << 3)	/* SCL line sense in */
#define OMAP_I2C_SYSTEST_SCL_O		(1 << 2)	/* SCL line drive out */
#define OMAP_I2C_SYSTEST_SDA_I		(1 << 1)	/* SDA line sense in */
#define OMAP_I2C_SYSTEST_SDA_O		(1 << 0)	/* SDA line drive out */
#endif

/* I2C System Status register (OMAP_I2C_SYSS): */
#define OMAP_I2C_SYSS_RDONE		(1 << 0)	/* Reset Done */

/* I2C System Configuration Register (OMAP_I2C_SYSC): */
#define OMAP_I2C_SYSC_SRST		(1 << 1)	/* Soft Reset */

/* REVISIT: Use platform_data instead of module parameters */
/* Fast Mode = 400 kHz, Standard = 100 kHz */
static int clock = 100; /* Default: 100 kHz */
module_param(clock, int, 0);
MODULE_PARM_DESC(clock, "Set I2C clock in kHz: 400=fast mode (default == 100)");

struct omap_i2c_dev {
	struct device		*dev;
	void __iomem		*base;		/* virtual */
	int			irq;
	struct clk		*iclk;		/* Interface clock */
	struct clk		*fclk;		/* Functional clock */
	struct completion	cmd_complete;
	struct resource		*ioarea;
	u16			cmd_err;
	u8			*buf;
	size_t			buf_len;
	struct i2c_adapter	adapter;
	unsigned		rev1:1;
	unsigned		idle:1;
	u16			iestate;	/* Saved interrupt register */
};

static inline void omap_i2c_write_reg(struct omap_i2c_dev *i2c_dev,
				      int reg, u16 val)
{
	__raw_writew(val, i2c_dev->base + reg);
}

static inline u16 omap_i2c_read_reg(struct omap_i2c_dev *i2c_dev, int reg)
{
	return __raw_readw(i2c_dev->base + reg);
}

static int omap_i2c_get_clocks(struct omap_i2c_dev *dev)
{
	if (cpu_is_omap16xx() || cpu_is_omap24xx()) {
		dev->iclk = clk_get(dev->dev, "i2c_ick");
		if (IS_ERR(dev->iclk)) {
			dev->iclk = NULL;
			return -ENODEV;
		}
	}

	dev->fclk = clk_get(dev->dev, "i2c_fck");
	if (IS_ERR(dev->fclk)) {
		if (dev->iclk != NULL) {
			clk_put(dev->iclk);
			dev->iclk = NULL;
		}
		dev->fclk = NULL;
		return -ENODEV;
	}

	return 0;
}

static void omap_i2c_put_clocks(struct omap_i2c_dev *dev)
{
	clk_put(dev->fclk);
	dev->fclk = NULL;
	if (dev->iclk != NULL) {
		clk_put(dev->iclk);
		dev->iclk = NULL;
	}
}

static void omap_i2c_unidle(struct omap_i2c_dev *dev)
{
	if (dev->iclk != NULL)
		clk_enable(dev->iclk);
	clk_enable(dev->fclk);
	dev->idle = 0;
	if (dev->iestate)
		omap_i2c_write_reg(dev, OMAP_I2C_IE_REG, dev->iestate);
}

static void omap_i2c_idle(struct omap_i2c_dev *dev)
{
	u16 iv;

	dev->iestate = omap_i2c_read_reg(dev, OMAP_I2C_IE_REG);
	omap_i2c_write_reg(dev, OMAP_I2C_IE_REG, 0);
	if (dev->rev1) {
		iv = omap_i2c_read_reg(dev, OMAP_I2C_IV_REG);	/* Read clears */
	} else {
		omap_i2c_write_reg(dev, OMAP_I2C_STAT_REG, dev->iestate);

		/* Flush posted write before the dev->idle store occurs */
		omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG);
	}
	dev->idle = 1;
	clk_disable(dev->fclk);
	if (dev->iclk != NULL)
		clk_disable(dev->iclk);
}

static int omap_i2c_init(struct omap_i2c_dev *dev)
{
	u16 psc = 0;
	unsigned long fclk_rate = 12000000;
	unsigned long timeout;

	if (!dev->rev1) {
		omap_i2c_write_reg(dev, OMAP_I2C_SYSC_REG, OMAP_I2C_SYSC_SRST);
		/* For some reason we need to set the EN bit before the
		 * reset done bit gets set. */
		timeout = jiffies + OMAP_I2C_TIMEOUT;
		omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
		while (!(omap_i2c_read_reg(dev, OMAP_I2C_SYSS_REG) &
			 OMAP_I2C_SYSS_RDONE)) {
			if (time_after(jiffies, timeout)) {
				dev_warn(dev->dev, "timeout waiting "
						"for controller reset\n");
				return -ETIMEDOUT;
			}
			msleep(1);
		}
	}
	omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);

	if (cpu_class_is_omap1()) {
		struct clk *armxor_ck;

		armxor_ck = clk_get(NULL, "armxor_ck");
		if (IS_ERR(armxor_ck))
			dev_warn(dev->dev, "Could not get armxor_ck\n");
		else {
			fclk_rate = clk_get_rate(armxor_ck);
			clk_put(armxor_ck);
		}
		/* TRM for 5912 says the I2C clock must be prescaled to be
		 * between 7 - 12 MHz. The XOR input clock is typically
		 * 12, 13 or 19.2 MHz. So we should have code that produces:
		 *
		 * XOR MHz	Divider		Prescaler
		 * 12		1		0
		 * 13		2		1
		 * 19.2		2		1
		 */
		if (fclk_rate > 12000000)
			psc = fclk_rate / 12000000;
	}

	/* Setup clock prescaler to obtain approx 12MHz I2C module clock: */
	omap_i2c_write_reg(dev, OMAP_I2C_PSC_REG, psc);

	/* Program desired operating rate */
	fclk_rate /= (psc + 1) * 1000;
	if (psc > 2)
		psc = 2;

	omap_i2c_write_reg(dev, OMAP_I2C_SCLL_REG,
			   fclk_rate / (clock * 2) - 7 + psc);
	omap_i2c_write_reg(dev, OMAP_I2C_SCLH_REG,
			   fclk_rate / (clock * 2) - 7 + psc);

	/* Take the I2C module out of reset: */
	omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);

	/* Enable interrupts */
	omap_i2c_write_reg(dev, OMAP_I2C_IE_REG,
			   (OMAP_I2C_IE_XRDY | OMAP_I2C_IE_RRDY |
			    OMAP_I2C_IE_ARDY | OMAP_I2C_IE_NACK |
			    OMAP_I2C_IE_AL));
	return 0;
}

/*
 * Waiting on Bus Busy
 */
static int omap_i2c_wait_for_bb(struct omap_i2c_dev *dev)
{
	unsigned long timeout;

	timeout = jiffies + OMAP_I2C_TIMEOUT;
	while (omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG) & OMAP_I2C_STAT_BB) {
		if (time_after(jiffies, timeout)) {
			dev_warn(dev->dev, "timeout waiting for bus ready\n");
			return -ETIMEDOUT;
		}
		msleep(1);
	}

	return 0;
}

/*
 * Low level master read/write transaction.
 */
static int omap_i2c_xfer_msg(struct i2c_adapter *adap,
			     struct i2c_msg *msg, int stop)
{
	struct omap_i2c_dev *dev = i2c_get_adapdata(adap);
	int r;
	u16 w;

	dev_dbg(dev->dev, "addr: 0x%04x, len: %d, flags: 0x%x, stop: %d\n",
		msg->addr, msg->len, msg->flags, stop);

	if (msg->len == 0)
		return -EINVAL;

	omap_i2c_write_reg(dev, OMAP_I2C_SA_REG, msg->addr);

	/* REVISIT: Could the STB bit of I2C_CON be used with probing? */
	dev->buf = msg->buf;
	dev->buf_len = msg->len;

	omap_i2c_write_reg(dev, OMAP_I2C_CNT_REG, dev->buf_len);

	init_completion(&dev->cmd_complete);
	dev->cmd_err = 0;

	w = OMAP_I2C_CON_EN | OMAP_I2C_CON_MST | OMAP_I2C_CON_STT;
	if (msg->flags & I2C_M_TEN)
		w |= OMAP_I2C_CON_XA;
	if (!(msg->flags & I2C_M_RD))
		w |= OMAP_I2C_CON_TRX;
	if (stop)
		w |= OMAP_I2C_CON_STP;
	omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, w);

	/*
	 * REVISIT: We should abort the transfer on signals, but the bus goes
	 * into arbitration and we're currently unable to recover from it.
	 */
	r = wait_for_completion_timeout(&dev->cmd_complete,
					OMAP_I2C_TIMEOUT);
	dev->buf_len = 0;
	if (r < 0)
		return r;
	if (r == 0) {
		dev_err(dev->dev, "controller timed out\n");
		omap_i2c_init(dev);
		return -ETIMEDOUT;
	}

	if (likely(!dev->cmd_err))
		return 0;

	/* We have an error */
	if (dev->cmd_err & (OMAP_I2C_STAT_AL | OMAP_I2C_STAT_ROVR |
			    OMAP_I2C_STAT_XUDF)) {
		omap_i2c_init(dev);
		return -EIO;
	}

	if (dev->cmd_err & OMAP_I2C_STAT_NACK) {
		if (msg->flags & I2C_M_IGNORE_NAK)
			return 0;
		if (stop) {
			w = omap_i2c_read_reg(dev, OMAP_I2C_CON_REG);
			w |= OMAP_I2C_CON_STP;
			omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, w);
		}
		return -EREMOTEIO;
	}
	return -EIO;
}


/*
 * Prepare controller for a transaction and call omap_i2c_xfer_msg
 * to do the work during IRQ processing.
 */
static int
omap_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
{
	struct omap_i2c_dev *dev = i2c_get_adapdata(adap);
	int i;
	int r;

	omap_i2c_unidle(dev);

	if ((r = omap_i2c_wait_for_bb(dev)) < 0)
		goto out;

	for (i = 0; i < num; i++) {
		r = omap_i2c_xfer_msg(adap, &msgs[i], (i == (num - 1)));
		if (r != 0)
			break;
	}

	if (r == 0)
		r = num;
out:
	omap_i2c_idle(dev);
	return r;
}

static u32
omap_i2c_func(struct i2c_adapter *adap)
{
	return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
}

static inline void
omap_i2c_complete_cmd(struct omap_i2c_dev *dev, u16 err)
{
	dev->cmd_err |= err;
	complete(&dev->cmd_complete);
}

static inline void
omap_i2c_ack_stat(struct omap_i2c_dev *dev, u16 stat)
{
	omap_i2c_write_reg(dev, OMAP_I2C_STAT_REG, stat);
}

static irqreturn_t
omap_i2c_rev1_isr(int this_irq, void *dev_id)
{
	struct omap_i2c_dev *dev = dev_id;
	u16 iv, w;

	if (dev->idle)
		return IRQ_NONE;

	iv = omap_i2c_read_reg(dev, OMAP_I2C_IV_REG);
	switch (iv) {
	case 0x00:	/* None */
		break;
	case 0x01:	/* Arbitration lost */
		dev_err(dev->dev, "Arbitration lost\n");
		omap_i2c_complete_cmd(dev, OMAP_I2C_STAT_AL);
		break;
	case 0x02:	/* No acknowledgement */
		omap_i2c_complete_cmd(dev, OMAP_I2C_STAT_NACK);
		omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_STP);
		break;
	case 0x03:	/* Register access ready */
		omap_i2c_complete_cmd(dev, 0);
		break;
	case 0x04:	/* Receive data ready */
		if (dev->buf_len) {
			w = omap_i2c_read_reg(dev, OMAP_I2C_DATA_REG);
			*dev->buf++ = w;
			dev->buf_len--;
			if (dev->buf_len) {
				*dev->buf++ = w >> 8;
				dev->buf_len--;
			}
		} else
			dev_err(dev->dev, "RRDY IRQ while no data requested\n");
		break;
	case 0x05:	/* Transmit data ready */
		if (dev->buf_len) {
			w = *dev->buf++;
			dev->buf_len--;
			if (dev->buf_len) {
				w |= *dev->buf++ << 8;
				dev->buf_len--;
			}
			omap_i2c_write_reg(dev, OMAP_I2C_DATA_REG, w);
		} else
			dev_err(dev->dev, "XRDY IRQ while no data to send\n");
		break;
	default:
		return IRQ_NONE;
	}

	return IRQ_HANDLED;
}

static irqreturn_t
omap_i2c_isr(int this_irq, void *dev_id)
{
	struct omap_i2c_dev *dev = dev_id;
	u16 bits;
	u16 stat, w;
	int count = 0;

	if (dev->idle)
		return IRQ_NONE;

	bits = omap_i2c_read_reg(dev, OMAP_I2C_IE_REG);
	while ((stat = (omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG))) & bits) {
		dev_dbg(dev->dev, "IRQ (ISR = 0x%04x)\n", stat);
		if (count++ == 100) {
			dev_warn(dev->dev, "Too much work in one IRQ\n");
			break;
		}

		omap_i2c_write_reg(dev, OMAP_I2C_STAT_REG, stat);

		if (stat & OMAP_I2C_STAT_ARDY) {
			omap_i2c_complete_cmd(dev, 0);
			continue;
		}
		if (stat & OMAP_I2C_STAT_RRDY) {
			w = omap_i2c_read_reg(dev, OMAP_I2C_DATA_REG);
			if (dev->buf_len) {
				*dev->buf++ = w;
				dev->buf_len--;
				if (dev->buf_len) {
					*dev->buf++ = w >> 8;
					dev->buf_len--;
				}
			} else
				dev_err(dev->dev, "RRDY IRQ while no data "
						"requested\n");
			omap_i2c_ack_stat(dev, OMAP_I2C_STAT_RRDY);
			continue;
		}
		if (stat & OMAP_I2C_STAT_XRDY) {
			w = 0;
			if (dev->buf_len) {
				w = *dev->buf++;
				dev->buf_len--;
				if (dev->buf_len) {
					w |= *dev->buf++ << 8;
					dev->buf_len--;
				}
			} else
				dev_err(dev->dev, "XRDY IRQ while no "
					"data to send\n");
			omap_i2c_write_reg(dev, OMAP_I2C_DATA_REG, w);
			omap_i2c_ack_stat(dev, OMAP_I2C_STAT_XRDY);
			continue;
		}
		if (stat & OMAP_I2C_STAT_ROVR) {
			dev_err(dev->dev, "Receive overrun\n");
			dev->cmd_err |= OMAP_I2C_STAT_ROVR;
		}
		if (stat & OMAP_I2C_STAT_XUDF) {
			dev_err(dev->dev, "Transmit overflow\n");
			dev->cmd_err |= OMAP_I2C_STAT_XUDF;
		}
		if (stat & OMAP_I2C_STAT_NACK) {
			omap_i2c_complete_cmd(dev, OMAP_I2C_STAT_NACK);
			omap_i2c_write_reg(dev, OMAP_I2C_CON_REG,
					   OMAP_I2C_CON_STP);
		}
		if (stat & OMAP_I2C_STAT_AL) {
			dev_err(dev->dev, "Arbitration lost\n");
			omap_i2c_complete_cmd(dev, OMAP_I2C_STAT_AL);
		}
	}

	return count ? IRQ_HANDLED : IRQ_NONE;
}

static const struct i2c_algorithm omap_i2c_algo = {
	.master_xfer	= omap_i2c_xfer,
	.functionality	= omap_i2c_func,
};

static int
omap_i2c_probe(struct platform_device *pdev)
{
	struct omap_i2c_dev	*dev;
	struct i2c_adapter	*adap;
	struct resource		*mem, *irq, *ioarea;
	int r;

	/* NOTE: driver uses the static register mapping */
	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!mem) {
		dev_err(&pdev->dev, "no mem resource?\n");
		return -ENODEV;
	}
	irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
	if (!irq) {
		dev_err(&pdev->dev, "no irq resource?\n");
		return -ENODEV;
	}

	ioarea = request_mem_region(mem->start, (mem->end - mem->start) + 1,
			pdev->name);
	if (!ioarea) {
		dev_err(&pdev->dev, "I2C region already claimed\n");
		return -EBUSY;
	}

	if (clock > 200)
		clock = 400;	/* Fast mode */
	else
		clock = 100;	/* Standard mode */

	dev = kzalloc(sizeof(struct omap_i2c_dev), GFP_KERNEL);
	if (!dev) {
		r = -ENOMEM;
		goto err_release_region;
	}

	dev->dev = &pdev->dev;
	dev->irq = irq->start;
	dev->base = ioremap(mem->start, mem->end - mem->start + 1);
	if (!dev->base) {
		r = -ENOMEM;
		goto err_free_mem;
	}

	platform_set_drvdata(pdev, dev);

	if ((r = omap_i2c_get_clocks(dev)) != 0)
		goto err_iounmap;

	omap_i2c_unidle(dev);

	if (cpu_is_omap15xx())
		dev->rev1 = omap_i2c_read_reg(dev, OMAP_I2C_REV_REG) < 0x20;

	/* reset ASAP, clearing any IRQs */
	omap_i2c_init(dev);

	r = request_irq(dev->irq, dev->rev1 ? omap_i2c_rev1_isr : omap_i2c_isr,
			0, pdev->name, dev);

	if (r) {
		dev_err(dev->dev, "failure requesting irq %i\n", dev->irq);
		goto err_unuse_clocks;
	}
	r = omap_i2c_read_reg(dev, OMAP_I2C_REV_REG) & 0xff;
	dev_info(dev->dev, "bus %d rev%d.%d at %d kHz\n",
		 pdev->id, r >> 4, r & 0xf, clock);

	adap = &dev->adapter;
	i2c_set_adapdata(adap, dev);
	adap->owner = THIS_MODULE;
	adap->class = I2C_CLASS_HWMON;
	strncpy(adap->name, "OMAP I2C adapter", sizeof(adap->name));
	adap->algo = &omap_i2c_algo;
	adap->dev.parent = &pdev->dev;

	/* i2c device drivers may be active on return from add_adapter() */
	adap->nr = pdev->id;
	r = i2c_add_numbered_adapter(adap);
	if (r) {
		dev_err(dev->dev, "failure adding adapter\n");
		goto err_free_irq;
	}

	omap_i2c_idle(dev);

	return 0;

err_free_irq:
	free_irq(dev->irq, dev);
err_unuse_clocks:
	omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
	omap_i2c_idle(dev);
	omap_i2c_put_clocks(dev);
err_iounmap:
	iounmap(dev->base);
err_free_mem:
	platform_set_drvdata(pdev, NULL);
	kfree(dev);
err_release_region:
	release_mem_region(mem->start, (mem->end - mem->start) + 1);

	return r;
}

static int
omap_i2c_remove(struct platform_device *pdev)
{
	struct omap_i2c_dev	*dev = platform_get_drvdata(pdev);
	struct resource		*mem;

	platform_set_drvdata(pdev, NULL);

	free_irq(dev->irq, dev);
	i2c_del_adapter(&dev->adapter);
	omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
	omap_i2c_put_clocks(dev);
	iounmap(dev->base);
	kfree(dev);
	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	release_mem_region(mem->start, (mem->end - mem->start) + 1);
	return 0;
}

static struct platform_driver omap_i2c_driver = {
	.probe		= omap_i2c_probe,
	.remove		= omap_i2c_remove,
	.driver		= {
		.name	= "i2c_omap",
		.owner	= THIS_MODULE,
	},
};

/* I2C may be needed to bring up other drivers */
static int __init
omap_i2c_init_driver(void)
{
	return platform_driver_register(&omap_i2c_driver);
}
subsys_initcall(omap_i2c_init_driver);

static void __exit omap_i2c_exit_driver(void)
{
	platform_driver_unregister(&omap_i2c_driver);
}
module_exit(omap_i2c_exit_driver);

MODULE_AUTHOR("MontaVista Software, Inc. (and others)");
MODULE_DESCRIPTION("TI OMAP I2C bus adapter");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:i2c_omap");
Commit	Line	Data
010d442c KS	1	/*
	2	* TI OMAP I2C master mode driver
	3	*
	4	* Copyright (C) 2003 MontaVista Software, Inc.
	5	* Copyright (C) 2004 Texas Instruments.
	6	*
	7	* Updated to work with multiple I2C interfaces on 24xx by
	8	* Tony Lindgren <tony@atomide.com> and Imre Deak <imre.deak@nokia.com>
	9	* Copyright (C) 2005 Nokia Corporation
	10	*
96de0e25	11	* Cleaned up by Juha Yrjölä <juha.yrjola@nokia.com>
010d442c KS	12	*
	13	* This program is free software; you can redistribute it and/or modify
	14	* it under the terms of the GNU General Public License as published by
	15	* the Free Software Foundation; either version 2 of the License, or
	16	* (at your option) any later version.
	17	*
	18	* This program is distributed in the hope that it will be useful,
	19	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	20	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	21	* GNU General Public License for more details.
	22	*
	23	* You should have received a copy of the GNU General Public License
	24	* along with this program; if not, write to the Free Software
	25	* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
	26	*/
	27
	28	#include <linux/module.h>
	29	#include <linux/delay.h>
	30	#include <linux/i2c.h>
	31	#include <linux/err.h>
	32	#include <linux/interrupt.h>
	33	#include <linux/completion.h>
	34	#include <linux/platform_device.h>
	35	#include <linux/clk.h>
	36
	37	#include <asm/io.h>
	38
	39	/* timeout waiting for the controller to respond */
	40	#define OMAP_I2C_TIMEOUT (msecs_to_jiffies(1000))
	41
	42	#define OMAP_I2C_REV_REG 0x00
	43	#define OMAP_I2C_IE_REG 0x04
	44	#define OMAP_I2C_STAT_REG 0x08
	45	#define OMAP_I2C_IV_REG 0x0c
	46	#define OMAP_I2C_SYSS_REG 0x10
	47	#define OMAP_I2C_BUF_REG 0x14
	48	#define OMAP_I2C_CNT_REG 0x18
	49	#define OMAP_I2C_DATA_REG 0x1c
	50	#define OMAP_I2C_SYSC_REG 0x20
	51	#define OMAP_I2C_CON_REG 0x24
	52	#define OMAP_I2C_OA_REG 0x28
	53	#define OMAP_I2C_SA_REG 0x2c
	54	#define OMAP_I2C_PSC_REG 0x30
	55	#define OMAP_I2C_SCLL_REG 0x34
	56	#define OMAP_I2C_SCLH_REG 0x38
	57	#define OMAP_I2C_SYSTEST_REG 0x3c
	58
	59	/* I2C Interrupt Enable Register (OMAP_I2C_IE): */
	60	#define OMAP_I2C_IE_XRDY (1 << 4) /* TX data ready int enable */
	61	#define OMAP_I2C_IE_RRDY (1 << 3) /* RX data ready int enable */
	62	#define OMAP_I2C_IE_ARDY (1 << 2) /* Access ready int enable */
	63	#define OMAP_I2C_IE_NACK (1 << 1) /* No ack interrupt enable */
	64	#define OMAP_I2C_IE_AL (1 << 0) /* Arbitration lost int ena */
	65
	66	/* I2C Status Register (OMAP_I2C_STAT): */
	67	#define OMAP_I2C_STAT_SBD (1 << 15) /* Single byte data */
	68	#define OMAP_I2C_STAT_BB (1 << 12) /* Bus busy */
	69	#define OMAP_I2C_STAT_ROVR (1 << 11) /* Receive overrun */
	70	#define OMAP_I2C_STAT_XUDF (1 << 10) /* Transmit underflow */
	71	#define OMAP_I2C_STAT_AAS (1 << 9) /* Address as slave */
	72	#define OMAP_I2C_STAT_AD0 (1 << 8) /* Address zero */
	73	#define OMAP_I2C_STAT_XRDY (1 << 4) /* Transmit data ready */
	74	#define OMAP_I2C_STAT_RRDY (1 << 3) /* Receive data ready */
	75	#define OMAP_I2C_STAT_ARDY (1 << 2) /* Register access ready */
76	#define OMAP_I2C_STAT_NACK (1 << 1) /* No ack interrupt enable */
77	#define OMAP_I2C_STAT_AL (1 << 0) /* Arbitration lost int ena */
78
79	/* I2C Buffer Configuration Register (OMAP_I2C_BUF): */
80	#define OMAP_I2C_BUF_RDMA_EN (1 << 15) /* RX DMA channel enable */
81	#define OMAP_I2C_BUF_XDMA_EN (1 << 7) /* TX DMA channel enable */
82
83	/* I2C Configuration Register (OMAP_I2C_CON): */
84	#define OMAP_I2C_CON_EN (1 << 15) /* I2C module enable */
85	#define OMAP_I2C_CON_BE (1 << 14) /* Big endian mode */
86	#define OMAP_I2C_CON_STB (1 << 11) /* Start byte mode (master) */
87	#define OMAP_I2C_CON_MST (1 << 10) /* Master/slave mode */
88	#define OMAP_I2C_CON_TRX (1 << 9) /* TX/RX mode (master only) */
89	#define OMAP_I2C_CON_XA (1 << 8) /* Expand address */
90	#define OMAP_I2C_CON_RM (1 << 2) /* Repeat mode (master only) */
91	#define OMAP_I2C_CON_STP (1 << 1) /* Stop cond (master only) */
92	#define OMAP_I2C_CON_STT (1 << 0) /* Start condition (master) */
93
94	/* I2C System Test Register (OMAP_I2C_SYSTEST): */
95	#ifdef DEBUG
96	#define OMAP_I2C_SYSTEST_ST_EN (1 << 15) /* System test enable */
97	#define OMAP_I2C_SYSTEST_FREE (1 << 14) /* Free running mode */
98	#define OMAP_I2C_SYSTEST_TMODE_MASK (3 << 12) /* Test mode select */
99	#define OMAP_I2C_SYSTEST_TMODE_SHIFT (12) /* Test mode select */
100	#define OMAP_I2C_SYSTEST_SCL_I (1 << 3) /* SCL line sense in */
101	#define OMAP_I2C_SYSTEST_SCL_O (1 << 2) /* SCL line drive out */
102	#define OMAP_I2C_SYSTEST_SDA_I (1 << 1) /* SDA line sense in */
103	#define OMAP_I2C_SYSTEST_SDA_O (1 << 0) /* SDA line drive out */
104	#endif
105
106	/* I2C System Status register (OMAP_I2C_SYSS): */
107	#define OMAP_I2C_SYSS_RDONE (1 << 0) /* Reset Done */
108
109	/* I2C System Configuration Register (OMAP_I2C_SYSC): */
110	#define OMAP_I2C_SYSC_SRST (1 << 1) /* Soft Reset */
111
112	/* REVISIT: Use platform_data instead of module parameters */
113	/* Fast Mode = 400 kHz, Standard = 100 kHz */
114	static int clock = 100; /* Default: 100 kHz */
115	module_param(clock, int, 0);
116	MODULE_PARM_DESC(clock, "Set I2C clock in kHz: 400=fast mode (default == 100)");
117
118	struct omap_i2c_dev {
119	struct device *dev;
120	void __iomem base; / virtual */
121	int irq;
122	struct clk iclk; / Interface clock */
123	struct clk fclk; / Functional clock */
124	struct completion cmd_complete;
125	struct resource *ioarea;
126	u16 cmd_err;
127	u8 *buf;
128	size_t buf_len;
129	struct i2c_adapter adapter;
130	unsigned rev1:1;
f08ac4e7 TL	131	unsigned idle:1;
f08ac4e7 TL	132	u16 iestate; /* Saved interrupt register */
010d442c KS	133	};
	134
	135	static inline void omap_i2c_write_reg(struct omap_i2c_dev *i2c_dev,
	136	int reg, u16 val)
	137	{
	138	__raw_writew(val, i2c_dev->base + reg);
	139	}
	140
	141	static inline u16 omap_i2c_read_reg(struct omap_i2c_dev *i2c_dev, int reg)
	142	{
	143	return __raw_readw(i2c_dev->base + reg);
	144	}
	145
	146	static int omap_i2c_get_clocks(struct omap_i2c_dev *dev)
	147	{
	148	if (cpu_is_omap16xx() \|\| cpu_is_omap24xx()) {
	149	dev->iclk = clk_get(dev->dev, "i2c_ick");
	150	if (IS_ERR(dev->iclk)) {
	151	dev->iclk = NULL;
	152	return -ENODEV;
	153	}
	154	}
	155
	156	dev->fclk = clk_get(dev->dev, "i2c_fck");
	157	if (IS_ERR(dev->fclk)) {
	158	if (dev->iclk != NULL) {
	159	clk_put(dev->iclk);
	160	dev->iclk = NULL;
	161	}
	162	dev->fclk = NULL;
	163	return -ENODEV;
	164	}
	165
	166	return 0;
	167	}
	168
	169	static void omap_i2c_put_clocks(struct omap_i2c_dev *dev)
	170	{
	171	clk_put(dev->fclk);
	172	dev->fclk = NULL;
	173	if (dev->iclk != NULL) {
	174	clk_put(dev->iclk);
	175	dev->iclk = NULL;
	176	}
	177	}
	178
f08ac4e7	179	static void omap_i2c_unidle(struct omap_i2c_dev *dev)
010d442c KS	180	{
	181	if (dev->iclk != NULL)
	182	clk_enable(dev->iclk);
	183	clk_enable(dev->fclk);
0cbbcffd	184	dev->idle = 0;
f08ac4e7 TL	185	if (dev->iestate)
f08ac4e7 TL	186	omap_i2c_write_reg(dev, OMAP_I2C_IE_REG, dev->iestate);
010d442c KS	187	}
010d442c KS	188
f08ac4e7	189	static void omap_i2c_idle(struct omap_i2c_dev *dev)
010d442c	190	{
f08ac4e7 TL	191	u16 iv;
f08ac4e7 TL	192
f08ac4e7 TL	193	dev->iestate = omap_i2c_read_reg(dev, OMAP_I2C_IE_REG);
f08ac4e7 TL	194	omap_i2c_write_reg(dev, OMAP_I2C_IE_REG, 0);
0cbbcffd	195	if (dev->rev1) {
f08ac4e7	196	iv = omap_i2c_read_reg(dev, OMAP_I2C_IV_REG); /* Read clears */
0cbbcffd	197	} else {
f08ac4e7	198	omap_i2c_write_reg(dev, OMAP_I2C_STAT_REG, dev->iestate);
0cbbcffd PW	199
	200	/* Flush posted write before the dev->idle store occurs */
	201	omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG);
	202	}
	203	dev->idle = 1;
f08ac4e7	204	clk_disable(dev->fclk);
010d442c KS	205	if (dev->iclk != NULL)
010d442c KS	206	clk_disable(dev->iclk);
010d442c KS	207	}
	208
	209	static int omap_i2c_init(struct omap_i2c_dev *dev)
	210	{
	211	u16 psc = 0;
	212	unsigned long fclk_rate = 12000000;
	213	unsigned long timeout;
	214
	215	if (!dev->rev1) {
	216	omap_i2c_write_reg(dev, OMAP_I2C_SYSC_REG, OMAP_I2C_SYSC_SRST);
	217	/* For some reason we need to set the EN bit before the
	218	* reset done bit gets set. */
	219	timeout = jiffies + OMAP_I2C_TIMEOUT;
	220	omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
	221	while (!(omap_i2c_read_reg(dev, OMAP_I2C_SYSS_REG) &
	222	OMAP_I2C_SYSS_RDONE)) {
	223	if (time_after(jiffies, timeout)) {
fce3ff03	224	dev_warn(dev->dev, "timeout waiting "
010d442c KS	225	"for controller reset\n");
	226	return -ETIMEDOUT;
	227	}
	228	msleep(1);
	229	}
	230	}
	231	omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
	232
	233	if (cpu_class_is_omap1()) {
	234	struct clk *armxor_ck;
	235
	236	armxor_ck = clk_get(NULL, "armxor_ck");
	237	if (IS_ERR(armxor_ck))
	238	dev_warn(dev->dev, "Could not get armxor_ck\n");
	239	else {
	240	fclk_rate = clk_get_rate(armxor_ck);
	241	clk_put(armxor_ck);
	242	}
	243	/* TRM for 5912 says the I2C clock must be prescaled to be
	244	* between 7 - 12 MHz. The XOR input clock is typically
	245	* 12, 13 or 19.2 MHz. So we should have code that produces:
	246	*
	247	* XOR MHz Divider Prescaler
	248	* 12 1 0
	249	* 13 2 1
	250	* 19.2 2 1
	251	*/
d7aef138 JD	252	if (fclk_rate > 12000000)
d7aef138 JD	253	psc = fclk_rate / 12000000;
010d442c KS	254	}
	255
	256	/* Setup clock prescaler to obtain approx 12MHz I2C module clock: */
	257	omap_i2c_write_reg(dev, OMAP_I2C_PSC_REG, psc);
	258
	259	/* Program desired operating rate */
	260	fclk_rate /= (psc + 1) * 1000;
	261	if (psc > 2)
	262	psc = 2;
	263
	264	omap_i2c_write_reg(dev, OMAP_I2C_SCLL_REG,
	265	fclk_rate / (clock * 2) - 7 + psc);
	266	omap_i2c_write_reg(dev, OMAP_I2C_SCLH_REG,
	267	fclk_rate / (clock * 2) - 7 + psc);
	268
	269	/* Take the I2C module out of reset: */
	270	omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
	271
	272	/* Enable interrupts */
	273	omap_i2c_write_reg(dev, OMAP_I2C_IE_REG,
	274	(OMAP_I2C_IE_XRDY \| OMAP_I2C_IE_RRDY \|
	275	OMAP_I2C_IE_ARDY \| OMAP_I2C_IE_NACK \|
	276	OMAP_I2C_IE_AL));
	277	return 0;
	278	}
	279
	280	/*
	281	* Waiting on Bus Busy
	282	*/
	283	static int omap_i2c_wait_for_bb(struct omap_i2c_dev *dev)
	284	{
	285	unsigned long timeout;
	286
	287	timeout = jiffies + OMAP_I2C_TIMEOUT;
	288	while (omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG) & OMAP_I2C_STAT_BB) {
	289	if (time_after(jiffies, timeout)) {
	290	dev_warn(dev->dev, "timeout waiting for bus ready\n");
	291	return -ETIMEDOUT;
	292	}
	293	msleep(1);
	294	}
	295
	296	return 0;
	297	}
	298
	299	/*
	300	* Low level master read/write transaction.
	301	*/
	302	static int omap_i2c_xfer_msg(struct i2c_adapter *adap,
	303	struct i2c_msg *msg, int stop)
	304	{
	305	struct omap_i2c_dev *dev = i2c_get_adapdata(adap);
	306	int r;
	307	u16 w;
	308
	309	dev_dbg(dev->dev, "addr: 0x%04x, len: %d, flags: 0x%x, stop: %d\n",
	310	msg->addr, msg->len, msg->flags, stop);
	311
	312	if (msg->len == 0)
	313	return -EINVAL;
	314
	315	omap_i2c_write_reg(dev, OMAP_I2C_SA_REG, msg->addr);
	316
	317	/* REVISIT: Could the STB bit of I2C_CON be used with probing? */
318	dev->buf = msg->buf;
319	dev->buf_len = msg->len;
320
321	omap_i2c_write_reg(dev, OMAP_I2C_CNT_REG, dev->buf_len);
322
323	init_completion(&dev->cmd_complete);
324	dev->cmd_err = 0;
325
326	w = OMAP_I2C_CON_EN \| OMAP_I2C_CON_MST \| OMAP_I2C_CON_STT;
327	if (msg->flags & I2C_M_TEN)
328	w \|= OMAP_I2C_CON_XA;
329	if (!(msg->flags & I2C_M_RD))
330	w \|= OMAP_I2C_CON_TRX;
331	if (stop)
332	w \|= OMAP_I2C_CON_STP;
333	omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, w);
334
b7af349b JN	335	/*
	336	* REVISIT: We should abort the transfer on signals, but the bus goes
	337	* into arbitration and we're currently unable to recover from it.
	338	*/
	339	r = wait_for_completion_timeout(&dev->cmd_complete,
	340	OMAP_I2C_TIMEOUT);
010d442c KS	341	dev->buf_len = 0;
	342	if (r < 0)
	343	return r;
	344	if (r == 0) {
	345	dev_err(dev->dev, "controller timed out\n");
	346	omap_i2c_init(dev);
	347	return -ETIMEDOUT;
	348	}
	349
	350	if (likely(!dev->cmd_err))
	351	return 0;
	352
	353	/* We have an error */
	354	if (dev->cmd_err & (OMAP_I2C_STAT_AL \| OMAP_I2C_STAT_ROVR \|
	355	OMAP_I2C_STAT_XUDF)) {
	356	omap_i2c_init(dev);
	357	return -EIO;
	358	}
	359
	360	if (dev->cmd_err & OMAP_I2C_STAT_NACK) {
	361	if (msg->flags & I2C_M_IGNORE_NAK)
	362	return 0;
	363	if (stop) {
	364	w = omap_i2c_read_reg(dev, OMAP_I2C_CON_REG);
	365	w \|= OMAP_I2C_CON_STP;
	366	omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, w);
	367	}
	368	return -EREMOTEIO;
	369	}
	370	return -EIO;
	371	}
	372
	373
	374	/*
	375	* Prepare controller for a transaction and call omap_i2c_xfer_msg
	376	* to do the work during IRQ processing.
	377	*/
	378	static int
	379	omap_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
	380	{
	381	struct omap_i2c_dev *dev = i2c_get_adapdata(adap);
	382	int i;
	383	int r;
	384
f08ac4e7	385	omap_i2c_unidle(dev);
010d442c	386
010d442c KS	387	if ((r = omap_i2c_wait_for_bb(dev)) < 0)
	388	goto out;
	389
	390	for (i = 0; i < num; i++) {
	391	r = omap_i2c_xfer_msg(adap, &msgs[i], (i == (num - 1)));
	392	if (r != 0)
	393	break;
	394	}
	395
	396	if (r == 0)
	397	r = num;
	398	out:
f08ac4e7	399	omap_i2c_idle(dev);
010d442c KS	400	return r;
	401	}
	402
	403	static u32
	404	omap_i2c_func(struct i2c_adapter *adap)
	405	{
	406	return I2C_FUNC_I2C \| (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
	407	}
	408
	409	static inline void
	410	omap_i2c_complete_cmd(struct omap_i2c_dev *dev, u16 err)
	411	{
	412	dev->cmd_err \|= err;
	413	complete(&dev->cmd_complete);
	414	}
	415
	416	static inline void
	417	omap_i2c_ack_stat(struct omap_i2c_dev *dev, u16 stat)
	418	{
	419	omap_i2c_write_reg(dev, OMAP_I2C_STAT_REG, stat);
	420	}
	421
	422	static irqreturn_t
7d12e780	423	omap_i2c_rev1_isr(int this_irq, void *dev_id)
010d442c KS	424	{
	425	struct omap_i2c_dev *dev = dev_id;
	426	u16 iv, w;
	427
f08ac4e7 TL	428	if (dev->idle)
	429	return IRQ_NONE;
	430
010d442c KS	431	iv = omap_i2c_read_reg(dev, OMAP_I2C_IV_REG);
	432	switch (iv) {
	433	case 0x00: /* None */
	434	break;
	435	case 0x01: /* Arbitration lost */
	436	dev_err(dev->dev, "Arbitration lost\n");
	437	omap_i2c_complete_cmd(dev, OMAP_I2C_STAT_AL);
	438	break;
	439	case 0x02: /* No acknowledgement */
	440	omap_i2c_complete_cmd(dev, OMAP_I2C_STAT_NACK);
	441	omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_STP);
	442	break;
	443	case 0x03: /* Register access ready */
	444	omap_i2c_complete_cmd(dev, 0);
	445	break;
	446	case 0x04: /* Receive data ready */
	447	if (dev->buf_len) {
	448	w = omap_i2c_read_reg(dev, OMAP_I2C_DATA_REG);
	449	*dev->buf++ = w;
	450	dev->buf_len--;
	451	if (dev->buf_len) {
	452	*dev->buf++ = w >> 8;
	453	dev->buf_len--;
	454	}
	455	} else
	456	dev_err(dev->dev, "RRDY IRQ while no data requested\n");
	457	break;
	458	case 0x05: /* Transmit data ready */
	459	if (dev->buf_len) {
	460	w = *dev->buf++;
	461	dev->buf_len--;
	462	if (dev->buf_len) {
	463	w \|= *dev->buf++ << 8;
	464	dev->buf_len--;
	465	}
	466	omap_i2c_write_reg(dev, OMAP_I2C_DATA_REG, w);
	467	} else
	468	dev_err(dev->dev, "XRDY IRQ while no data to send\n");
	469	break;
	470	default:
	471	return IRQ_NONE;
	472	}
	473
	474	return IRQ_HANDLED;
	475	}
	476
	477	static irqreturn_t
7d12e780	478	omap_i2c_isr(int this_irq, void *dev_id)
010d442c KS	479	{
	480	struct omap_i2c_dev *dev = dev_id;
	481	u16 bits;
	482	u16 stat, w;
	483	int count = 0;
	484
f08ac4e7 TL	485	if (dev->idle)
	486	return IRQ_NONE;
	487
010d442c KS	488	bits = omap_i2c_read_reg(dev, OMAP_I2C_IE_REG);
	489	while ((stat = (omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG))) & bits) {
	490	dev_dbg(dev->dev, "IRQ (ISR = 0x%04x)\n", stat);
	491	if (count++ == 100) {
	492	dev_warn(dev->dev, "Too much work in one IRQ\n");
	493	break;
	494	}
	495
	496	omap_i2c_write_reg(dev, OMAP_I2C_STAT_REG, stat);
	497
	498	if (stat & OMAP_I2C_STAT_ARDY) {
	499	omap_i2c_complete_cmd(dev, 0);
	500	continue;
	501	}
	502	if (stat & OMAP_I2C_STAT_RRDY) {
	503	w = omap_i2c_read_reg(dev, OMAP_I2C_DATA_REG);
	504	if (dev->buf_len) {
	505	*dev->buf++ = w;
	506	dev->buf_len--;
	507	if (dev->buf_len) {
	508	*dev->buf++ = w >> 8;
	509	dev->buf_len--;
	510	}
	511	} else
fce3ff03	512	dev_err(dev->dev, "RRDY IRQ while no data "
010d442c KS	513	"requested\n");
	514	omap_i2c_ack_stat(dev, OMAP_I2C_STAT_RRDY);
	515	continue;
	516	}
	517	if (stat & OMAP_I2C_STAT_XRDY) {
	518	w = 0;
	519	if (dev->buf_len) {
	520	w = *dev->buf++;
	521	dev->buf_len--;
	522	if (dev->buf_len) {
	523	w \|= *dev->buf++ << 8;
	524	dev->buf_len--;
	525	}
	526	} else
fce3ff03	527	dev_err(dev->dev, "XRDY IRQ while no "
010d442c KS	528	"data to send\n");
	529	omap_i2c_write_reg(dev, OMAP_I2C_DATA_REG, w);
	530	omap_i2c_ack_stat(dev, OMAP_I2C_STAT_XRDY);
	531	continue;
	532	}
	533	if (stat & OMAP_I2C_STAT_ROVR) {
	534	dev_err(dev->dev, "Receive overrun\n");
	535	dev->cmd_err \|= OMAP_I2C_STAT_ROVR;
	536	}
	537	if (stat & OMAP_I2C_STAT_XUDF) {
	538	dev_err(dev->dev, "Transmit overflow\n");
	539	dev->cmd_err \|= OMAP_I2C_STAT_XUDF;
	540	}
	541	if (stat & OMAP_I2C_STAT_NACK) {
	542	omap_i2c_complete_cmd(dev, OMAP_I2C_STAT_NACK);
	543	omap_i2c_write_reg(dev, OMAP_I2C_CON_REG,
	544	OMAP_I2C_CON_STP);
	545	}
	546	if (stat & OMAP_I2C_STAT_AL) {
	547	dev_err(dev->dev, "Arbitration lost\n");
	548	omap_i2c_complete_cmd(dev, OMAP_I2C_STAT_AL);
	549	}
	550	}
	551
	552	return count ? IRQ_HANDLED : IRQ_NONE;
	553	}
	554
8f9082c5	555	static const struct i2c_algorithm omap_i2c_algo = {
010d442c KS	556	.master_xfer = omap_i2c_xfer,
	557	.functionality = omap_i2c_func,
	558	};
	559
	560	static int
	561	omap_i2c_probe(struct platform_device *pdev)
	562	{
	563	struct omap_i2c_dev *dev;
	564	struct i2c_adapter *adap;
	565	struct resource mem, irq, *ioarea;
	566	int r;
	567
	568	/* NOTE: driver uses the static register mapping */
	569	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	570	if (!mem) {
	571	dev_err(&pdev->dev, "no mem resource?\n");
	572	return -ENODEV;
	573	}
	574	irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
	575	if (!irq) {
	576	dev_err(&pdev->dev, "no irq resource?\n");
	577	return -ENODEV;
	578	}
	579
	580	ioarea = request_mem_region(mem->start, (mem->end - mem->start) + 1,
	581	pdev->name);
	582	if (!ioarea) {
	583	dev_err(&pdev->dev, "I2C region already claimed\n");
	584	return -EBUSY;
	585	}
	586
	587	if (clock > 200)
	588	clock = 400; /* Fast mode */
	589	else
	590	clock = 100; /* Standard mode */
	591
	592	dev = kzalloc(sizeof(struct omap_i2c_dev), GFP_KERNEL);
	593	if (!dev) {
	594	r = -ENOMEM;
	595	goto err_release_region;
	596	}
	597
	598	dev->dev = &pdev->dev;
	599	dev->irq = irq->start;
55c381e4 RK	600	dev->base = ioremap(mem->start, mem->end - mem->start + 1);
	601	if (!dev->base) {
	602	r = -ENOMEM;
	603	goto err_free_mem;
	604	}
	605
010d442c KS	606	platform_set_drvdata(pdev, dev);
	607
	608	if ((r = omap_i2c_get_clocks(dev)) != 0)
55c381e4	609	goto err_iounmap;
010d442c	610
f08ac4e7	611	omap_i2c_unidle(dev);
010d442c KS	612
	613	if (cpu_is_omap15xx())
	614	dev->rev1 = omap_i2c_read_reg(dev, OMAP_I2C_REV_REG) < 0x20;
	615
	616	/* reset ASAP, clearing any IRQs */
	617	omap_i2c_init(dev);
	618
	619	r = request_irq(dev->irq, dev->rev1 ? omap_i2c_rev1_isr : omap_i2c_isr,
	620	0, pdev->name, dev);
	621
	622	if (r) {
	623	dev_err(dev->dev, "failure requesting irq %i\n", dev->irq);
	624	goto err_unuse_clocks;
	625	}
	626	r = omap_i2c_read_reg(dev, OMAP_I2C_REV_REG) & 0xff;
	627	dev_info(dev->dev, "bus %d rev%d.%d at %d kHz\n",
	628	pdev->id, r >> 4, r & 0xf, clock);
	629
	630	adap = &dev->adapter;
	631	i2c_set_adapdata(adap, dev);
	632	adap->owner = THIS_MODULE;
	633	adap->class = I2C_CLASS_HWMON;
	634	strncpy(adap->name, "OMAP I2C adapter", sizeof(adap->name));
	635	adap->algo = &omap_i2c_algo;
	636	adap->dev.parent = &pdev->dev;
	637
	638	/* i2c device drivers may be active on return from add_adapter() */
7c175499 DB	639	adap->nr = pdev->id;
7c175499 DB	640	r = i2c_add_numbered_adapter(adap);
010d442c KS	641	if (r) {
	642	dev_err(dev->dev, "failure adding adapter\n");
	643	goto err_free_irq;
	644	}
	645
f08ac4e7	646	omap_i2c_idle(dev);
010d442c KS	647
	648	return 0;
	649
	650	err_free_irq:
	651	free_irq(dev->irq, dev);
	652	err_unuse_clocks:
3e39752d	653	omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
f08ac4e7	654	omap_i2c_idle(dev);
010d442c	655	omap_i2c_put_clocks(dev);
55c381e4 RK	656	err_iounmap:
55c381e4 RK	657	iounmap(dev->base);
010d442c KS	658	err_free_mem:
	659	platform_set_drvdata(pdev, NULL);
	660	kfree(dev);
	661	err_release_region:
010d442c KS	662	release_mem_region(mem->start, (mem->end - mem->start) + 1);
	663
	664	return r;
	665	}
	666
	667	static int
	668	omap_i2c_remove(struct platform_device *pdev)
	669	{
	670	struct omap_i2c_dev *dev = platform_get_drvdata(pdev);
	671	struct resource *mem;
	672
	673	platform_set_drvdata(pdev, NULL);
	674
	675	free_irq(dev->irq, dev);
	676	i2c_del_adapter(&dev->adapter);
	677	omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
	678	omap_i2c_put_clocks(dev);
55c381e4	679	iounmap(dev->base);
010d442c KS	680	kfree(dev);
	681	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	682	release_mem_region(mem->start, (mem->end - mem->start) + 1);
	683	return 0;
	684	}
	685
	686	static struct platform_driver omap_i2c_driver = {
	687	.probe = omap_i2c_probe,
	688	.remove = omap_i2c_remove,
	689	.driver = {
	690	.name = "i2c_omap",
	691	.owner = THIS_MODULE,
	692	},
	693	};
	694
	695	/* I2C may be needed to bring up other drivers */
	696	static int __init
	697	omap_i2c_init_driver(void)
	698	{
	699	return platform_driver_register(&omap_i2c_driver);
	700	}
	701	subsys_initcall(omap_i2c_init_driver);
	702
	703	static void __exit omap_i2c_exit_driver(void)
	704	{
	705	platform_driver_unregister(&omap_i2c_driver);
	706	}
	707	module_exit(omap_i2c_exit_driver);
	708
	709	MODULE_AUTHOR("MontaVista Software, Inc. (and others)");
	710	MODULE_DESCRIPTION("TI OMAP I2C bus adapter");
	711	MODULE_LICENSE("GPL");
add8eda7	712	MODULE_ALIAS("platform:i2c_omap");