i2c: New Philips PNX bus driver

New I2C bus driver for Philips ARM boards (Philips IP3204 I2C IP
block). This I2C controller can be found on (at least) PNX010x,
PNX52xx and PNX4008 Philips boards.

Signed-off-by: Vitaly Wool <vitalywool@gmail.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

1 files changed, 708 insertions, 0 deletions

diff --git a/drivers/i2c/busses/i2c-pnx.c b/drivers/i2c/busses/i2c-pnx.c
new file mode 100644
index 00000000000..de0bca77e92
--- /dev/null
+++ b/drivers/i2c/busses/i2c-pnx.c
@@ -0,0 +1,708 @@
+/*
+ * Provides I2C support for Philips PNX010x/PNX4008 boards.
+ *
+ * Authors: Dennis Kovalev <dkovalev@ru.mvista.com>
+ *	    Vitaly Wool <vwool@ru.mvista.com>
+ *
+ * 2004-2006 (c) MontaVista Software, Inc. This file is licensed under
+ * the terms of the GNU General Public License version 2. This program
+ * is licensed "as is" without any warranty of any kind, whether express
+ * or implied.
+ */
+
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/ioport.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/timer.h>
+#include <linux/completion.h>
+#include <linux/platform_device.h>
+#include <linux/i2c-pnx.h>
+#include <asm/hardware.h>
+#include <asm/irq.h>
+#include <asm/uaccess.h>
+
+#define I2C_PNX_TIMEOUT		10 /* msec */
+#define I2C_PNX_SPEED_KHZ	100
+#define I2C_PNX_REGION_SIZE	0x100
+#define PNX_DEFAULT_FREQ	13 /* MHz */
+
+static inline int wait_timeout(long timeout, struct i2c_pnx_algo_data *data)
+{
+	while (timeout > 0 &&
+			(ioread32(I2C_REG_STS(data)) & mstatus_active)) {
+		mdelay(1);
+		timeout--;
+	}
+	return (timeout <= 0);
+}
+
+static inline int wait_reset(long timeout, struct i2c_pnx_algo_data *data)
+{
+	while (timeout > 0 &&
+			(ioread32(I2C_REG_CTL(data)) & mcntrl_reset)) {
+		mdelay(1);
+		timeout--;
+	}
+	return (timeout <= 0);
+}
+
+static inline void i2c_pnx_arm_timer(struct i2c_adapter *adap)
+{
+	struct i2c_pnx_algo_data *data = adap->algo_data;
+	struct timer_list *timer = &data->mif.timer;
+	int expires = I2C_PNX_TIMEOUT / (1000 / HZ);
+
+	del_timer_sync(timer);
+
+	dev_dbg(&adap->dev, "Timer armed at %lu plus %u jiffies.\n",
+		jiffies, expires);
+
+	timer->expires = jiffies + expires;
+	timer->data = (unsigned long)adap;
+
+	add_timer(timer);
+}
+
+/**
+ * i2c_pnx_start - start a device
+ * @slave_addr:		slave address
+ * @adap:		pointer to adapter structure
+ *
+ * Generate a START signal in the desired mode.
+ */
+static int i2c_pnx_start(unsigned char slave_addr, struct i2c_adapter *adap)
+{
+	struct i2c_pnx_algo_data *alg_data = adap->algo_data;
+
+	dev_dbg(&adap->dev, "%s(): addr 0x%x mode %d\n", __FUNCTION__,
+		slave_addr, alg_data->mif.mode);
+
+	/* Check for 7 bit slave addresses only */
+	if (slave_addr & ~0x7f) {
+		dev_err(&adap->dev, "%s: Invalid slave address %x. "
+		       "Only 7-bit addresses are supported\n",
+		       adap->name, slave_addr);
+		return -EINVAL;
+	}
+
+	/* First, make sure bus is idle */
+	if (wait_timeout(I2C_PNX_TIMEOUT, alg_data)) {
+		/* Somebody else is monopolizing the bus */
+		dev_err(&adap->dev, "%s: Bus busy. Slave addr = %02x, "
+		       "cntrl = %x, stat = %x\n",
+		       adap->name, slave_addr,
+		       ioread32(I2C_REG_CTL(alg_data)),
+		       ioread32(I2C_REG_STS(alg_data)));
+		return -EBUSY;
+	} else if (ioread32(I2C_REG_STS(alg_data)) & mstatus_afi) {
+		/* Sorry, we lost the bus */
+		dev_err(&adap->dev, "%s: Arbitration failure. "
+		       "Slave addr = %02x\n", adap->name, slave_addr);
+		return -EIO;
+	}
+
+	/*
+	 * OK, I2C is enabled and we have the bus.
+	 * Clear the current TDI and AFI status flags.
+	 */
+	iowrite32(ioread32(I2C_REG_STS(alg_data)) | mstatus_tdi | mstatus_afi,
+		  I2C_REG_STS(alg_data));
+
+	dev_dbg(&adap->dev, "%s(): sending %#x\n", __FUNCTION__,
+		(slave_addr << 1) | start_bit | alg_data->mif.mode);
+
+	/* Write the slave address, START bit and R/W bit */
+	iowrite32((slave_addr << 1) | start_bit | alg_data->mif.mode,
+		  I2C_REG_TX(alg_data));
+
+	dev_dbg(&adap->dev, "%s(): exit\n", __FUNCTION__);
+
+	return 0;
+}
+
+/**
+ * i2c_pnx_stop - stop a device
+ * @adap:		pointer to I2C adapter structure
+ *
+ * Generate a STOP signal to terminate the master transaction.
+ */
+static void i2c_pnx_stop(struct i2c_adapter *adap)
+{
+	struct i2c_pnx_algo_data *alg_data = adap->algo_data;
+	/* Only 1 msec max timeout due to interrupt context */
+	long timeout = 1000;
+
+	dev_dbg(&adap->dev, "%s(): entering: stat = %04x.\n",
+		__FUNCTION__, ioread32(I2C_REG_STS(alg_data)));
+
+	/* Write a STOP bit to TX FIFO */
+	iowrite32(0xff | stop_bit, I2C_REG_TX(alg_data));
+
+	/* Wait until the STOP is seen. */
+	while (timeout > 0 &&
+	       (ioread32(I2C_REG_STS(alg_data)) & mstatus_active)) {
+		/* may be called from interrupt context */
+		udelay(1);
+		timeout--;
+	}
+
+	dev_dbg(&adap->dev, "%s(): exiting: stat = %04x.\n",
+		__FUNCTION__, ioread32(I2C_REG_STS(alg_data)));
+}
+
+/**
+ * i2c_pnx_master_xmit - transmit data to slave
+ * @adap:		pointer to I2C adapter structure
+ *
+ * Sends one byte of data to the slave
+ */
+static int i2c_pnx_master_xmit(struct i2c_adapter *adap)
+{
+	struct i2c_pnx_algo_data *alg_data = adap->algo_data;
+	u32 val;
+
+	dev_dbg(&adap->dev, "%s(): entering: stat = %04x.\n",
+		__FUNCTION__, ioread32(I2C_REG_STS(alg_data)));
+
+	if (alg_data->mif.len > 0) {
+		/* We still have something to talk about... */
+		val = *alg_data->mif.buf++;
+
+		if (alg_data->mif.len == 1) {
+			val |= stop_bit;
+			if (!alg_data->last)
+				val |= start_bit;
+		}
+
+		alg_data->mif.len--;
+		iowrite32(val, I2C_REG_TX(alg_data));
+
+		dev_dbg(&adap->dev, "%s(): xmit %#x [%d]\n", __FUNCTION__,
+			val, alg_data->mif.len + 1);
+
+		if (alg_data->mif.len == 0) {
+			if (alg_data->last) {
+				/* Wait until the STOP is seen. */
+				if (wait_timeout(I2C_PNX_TIMEOUT, alg_data))
+					dev_err(&adap->dev, "The bus is still "
+						"active after timeout\n");
+			}
+			/* Disable master interrupts */
+			iowrite32(ioread32(I2C_REG_CTL(alg_data)) &
+				~(mcntrl_afie | mcntrl_naie | mcntrl_drmie),
+				  I2C_REG_CTL(alg_data));
+
+			del_timer_sync(&alg_data->mif.timer);
+
+			dev_dbg(&adap->dev, "%s(): Waking up xfer routine.\n",
+				__FUNCTION__);
+
+			complete(&alg_data->mif.complete);
+		}
+	} else if (alg_data->mif.len == 0) {
+		/* zero-sized transfer */
+		i2c_pnx_stop(adap);
+
+		/* Disable master interrupts. */
+		iowrite32(ioread32(I2C_REG_CTL(alg_data)) &
+			~(mcntrl_afie | mcntrl_naie | mcntrl_drmie),
+			  I2C_REG_CTL(alg_data));
+
+		/* Stop timer. */
+		del_timer_sync(&alg_data->mif.timer);
+		dev_dbg(&adap->dev, "%s(): Waking up xfer routine after "
+			"zero-xfer.\n", __FUNCTION__);
+
+		complete(&alg_data->mif.complete);
+	}
+
+	dev_dbg(&adap->dev, "%s(): exiting: stat = %04x.\n",
+		__FUNCTION__, ioread32(I2C_REG_STS(alg_data)));
+
+	return 0;
+}
+
+/**
+ * i2c_pnx_master_rcv - receive data from slave
+ * @adap:		pointer to I2C adapter structure
+ *
+ * Reads one byte data from the slave
+ */
+static int i2c_pnx_master_rcv(struct i2c_adapter *adap)
+{
+	struct i2c_pnx_algo_data *alg_data = adap->algo_data;
+	unsigned int val = 0;
+	u32 ctl = 0;
+
+	dev_dbg(&adap->dev, "%s(): entering: stat = %04x.\n",
+		__FUNCTION__, ioread32(I2C_REG_STS(alg_data)));
+
+	/* Check, whether there is already data,
+	 * or we didn't 'ask' for it yet.
+	 */
+	if (ioread32(I2C_REG_STS(alg_data)) & mstatus_rfe) {
+		dev_dbg(&adap->dev, "%s(): Write dummy data to fill "
+			"Rx-fifo...\n", __FUNCTION__);
+
+		if (alg_data->mif.len == 1) {
+			/* Last byte, do not acknowledge next rcv. */
+			val |= stop_bit;
+			if (!alg_data->last)
+				val |= start_bit;
+
+			/*
+			 * Enable interrupt RFDAIE (data in Rx fifo),
+			 * and disable DRMIE (need data for Tx)
+			 */
+			ctl = ioread32(I2C_REG_CTL(alg_data));
+			ctl |= mcntrl_rffie | mcntrl_daie;
+			ctl &= ~mcntrl_drmie;
+			iowrite32(ctl, I2C_REG_CTL(alg_data));
+		}
+
+		/*
+		 * Now we'll 'ask' for data:
+		 * For each byte we want to receive, we must
+		 * write a (dummy) byte to the Tx-FIFO.
+		 */
+		iowrite32(val, I2C_REG_TX(alg_data));
+
+		return 0;
+	}
+
+	/* Handle data. */
+	if (alg_data->mif.len > 0) {
+		val = ioread32(I2C_REG_RX(alg_data));
+		*alg_data->mif.buf++ = (u8) (val & 0xff);
+		dev_dbg(&adap->dev, "%s(): rcv 0x%x [%d]\n", __FUNCTION__, val,
+			alg_data->mif.len);
+
+		alg_data->mif.len--;
+		if (alg_data->mif.len == 0) {
+			if (alg_data->last)
+				/* Wait until the STOP is seen. */
+				if (wait_timeout(I2C_PNX_TIMEOUT, alg_data))
+					dev_err(&adap->dev, "The bus is still "
+						"active after timeout\n");
+
+			/* Disable master interrupts */
+			ctl = ioread32(I2C_REG_CTL(alg_data));
+			ctl &= ~(mcntrl_afie | mcntrl_naie | mcntrl_rffie |
+				 mcntrl_drmie | mcntrl_daie);
+			iowrite32(ctl, I2C_REG_CTL(alg_data));
+
+			/* Kill timer. */
+			del_timer_sync(&alg_data->mif.timer);
+			complete(&alg_data->mif.complete);
+		}
+	}
+
+	dev_dbg(&adap->dev, "%s(): exiting: stat = %04x.\n",
+		__FUNCTION__, ioread32(I2C_REG_STS(alg_data)));
+
+	return 0;
+}
+
+static irqreturn_t
+i2c_pnx_interrupt(int irq, void *dev_id, struct pt_regs *regs)
+{
+	u32 stat, ctl;
+	struct i2c_adapter *adap = dev_id;
+	struct i2c_pnx_algo_data *alg_data = adap->algo_data;
+
+	dev_dbg(&adap->dev, "%s(): mstat = %x mctrl = %x, mode = %d\n",
+		__FUNCTION__,
+		ioread32(I2C_REG_STS(alg_data)),
+		ioread32(I2C_REG_CTL(alg_data)),
+		alg_data->mif.mode);
+	stat = ioread32(I2C_REG_STS(alg_data));
+
+	/* let's see what kind of event this is */
+	if (stat & mstatus_afi) {
+		/* We lost arbitration in the midst of a transfer */
+		alg_data->mif.ret = -EIO;
+
+		/* Disable master interrupts. */
+		ctl = ioread32(I2C_REG_CTL(alg_data));
+		ctl &= ~(mcntrl_afie | mcntrl_naie | mcntrl_rffie |
+			 mcntrl_drmie);
+		iowrite32(ctl, I2C_REG_CTL(alg_data));
+
+		/* Stop timer, to prevent timeout. */
+		del_timer_sync(&alg_data->mif.timer);
+		complete(&alg_data->mif.complete);
+	} else if (stat & mstatus_nai) {
+		/* Slave did not acknowledge, generate a STOP */
+		dev_dbg(&adap->dev, "%s(): "
+			"Slave did not acknowledge, generating a STOP.\n",
+			__FUNCTION__);
+		i2c_pnx_stop(adap);
+
+		/* Disable master interrupts. */
+		ctl = ioread32(I2C_REG_CTL(alg_data));
+		ctl &= ~(mcntrl_afie | mcntrl_naie | mcntrl_rffie |
+			 mcntrl_drmie);
+		iowrite32(ctl, I2C_REG_CTL(alg_data));
+
+		/* Our return value. */
+		alg_data->mif.ret = -EIO;
+
+		/* Stop timer, to prevent timeout. */
+		del_timer_sync(&alg_data->mif.timer);
+		complete(&alg_data->mif.complete);
+	} else {
+		/*
+		 * Two options:
+		 * - Master Tx needs data.
+		 * - There is data in the Rx-fifo
+		 * The latter is only the case if we have requested for data,
+		 * via a dummy write. (See 'i2c_pnx_master_rcv'.)
+		 * We therefore check, as a sanity check, whether that interrupt
+		 * has been enabled.
+		 */
+		if ((stat & mstatus_drmi) || !(stat & mstatus_rfe)) {
+			if (alg_data->mif.mode == I2C_SMBUS_WRITE) {
+				i2c_pnx_master_xmit(adap);
+			} else if (alg_data->mif.mode == I2C_SMBUS_READ) {
+				i2c_pnx_master_rcv(adap);
+			}
+		}
+	}
+
+	/* Clear TDI and AFI bits */
+	stat = ioread32(I2C_REG_STS(alg_data));
+	iowrite32(stat | mstatus_tdi | mstatus_afi, I2C_REG_STS(alg_data));
+
+	dev_dbg(&adap->dev, "%s(): exiting, stat = %x ctrl = %x.\n",
+		 __FUNCTION__, ioread32(I2C_REG_STS(alg_data)),
+		 ioread32(I2C_REG_CTL(alg_data)));
+
+	return IRQ_HANDLED;
+}
+
+static void i2c_pnx_timeout(unsigned long data)
+{
+	struct i2c_adapter *adap = (struct i2c_adapter *)data;
+	struct i2c_pnx_algo_data *alg_data = adap->algo_data;
+	u32 ctl;
+
+	dev_err(&adap->dev, "Master timed out. stat = %04x, cntrl = %04x. "
+	       "Resetting master...\n",
+	       ioread32(I2C_REG_STS(alg_data)),
+	       ioread32(I2C_REG_CTL(alg_data)));
+
+	/* Reset master and disable interrupts */
+	ctl = ioread32(I2C_REG_CTL(alg_data));
+	ctl &= ~(mcntrl_afie | mcntrl_naie | mcntrl_rffie | mcntrl_drmie);
+	iowrite32(ctl, I2C_REG_CTL(alg_data));
+
+	ctl |= mcntrl_reset;
+	iowrite32(ctl, I2C_REG_CTL(alg_data));
+	wait_reset(I2C_PNX_TIMEOUT, alg_data);
+	alg_data->mif.ret = -EIO;
+	complete(&alg_data->mif.complete);
+}
+
+static inline void bus_reset_if_active(struct i2c_adapter *adap)
+{
+	struct i2c_pnx_algo_data *alg_data = adap->algo_data;
+	u32 stat;
+
+	if ((stat = ioread32(I2C_REG_STS(alg_data))) & mstatus_active) {
+		dev_err(&adap->dev,
+			"%s: Bus is still active after xfer. Reset it...\n",
+		       adap->name);
+		iowrite32(ioread32(I2C_REG_CTL(alg_data)) | mcntrl_reset,
+			  I2C_REG_CTL(alg_data));
+		wait_reset(I2C_PNX_TIMEOUT, alg_data);
+	} else if (!(stat & mstatus_rfe) || !(stat & mstatus_tfe)) {
+		/* If there is data in the fifo's after transfer,
+		 * flush fifo's by reset.
+		 */
+		iowrite32(ioread32(I2C_REG_CTL(alg_data)) | mcntrl_reset,
+			  I2C_REG_CTL(alg_data));
+		wait_reset(I2C_PNX_TIMEOUT, alg_data);
+	} else if (stat & mstatus_nai) {
+		iowrite32(ioread32(I2C_REG_CTL(alg_data)) | mcntrl_reset,
+			  I2C_REG_CTL(alg_data));
+		wait_reset(I2C_PNX_TIMEOUT, alg_data);
+	}
+}
+
+/**
+ * i2c_pnx_xfer - generic transfer entry point
+ * @adap:		pointer to I2C adapter structure
+ * @msgs:		array of messages
+ * @num:		number of messages
+ *
+ * Initiates the transfer
+ */
+static int
+i2c_pnx_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
+{
+	struct i2c_msg *pmsg;
+	int rc = 0, completed = 0, i;
+	struct i2c_pnx_algo_data *alg_data = adap->algo_data;
+	u32 stat = ioread32(I2C_REG_STS(alg_data));
+
+	dev_dbg(&adap->dev, "%s(): entering: %d messages, stat = %04x.\n",
+		__FUNCTION__, num, ioread32(I2C_REG_STS(alg_data)));
+
+	bus_reset_if_active(adap);
+
+	/* Process transactions in a loop. */
+	for (i = 0; rc >= 0 && i < num; i++) {
+		u8 addr;
+
+		pmsg = &msgs[i];
+		addr = pmsg->addr;
+
+		if (pmsg->flags & I2C_M_TEN) {
+			dev_err(&adap->dev,
+				"%s: 10 bits addr not supported!\n",
+				adap->name);
+			rc = -EINVAL;
+			break;
+		}
+
+		alg_data->mif.buf = pmsg->buf;
+		alg_data->mif.len = pmsg->len;
+		alg_data->mif.mode = (pmsg->flags & I2C_M_RD) ?
+			I2C_SMBUS_READ : I2C_SMBUS_WRITE;
+		alg_data->mif.ret = 0;
+		alg_data->last = (i == num - 1);
+
+		dev_dbg(&adap->dev, "%s(): mode %d, %d bytes\n", __FUNCTION__,
+			alg_data->mif.mode,
+			alg_data->mif.len);
+
+		i2c_pnx_arm_timer(adap);
+
+		/* initialize the completion var */
+		init_completion(&alg_data->mif.complete);
+
+		/* Enable master interrupt */
+		iowrite32(ioread32(I2C_REG_CTL(alg_data)) | mcntrl_afie |
+				mcntrl_naie | mcntrl_drmie,
+			  I2C_REG_CTL(alg_data));
+
+		/* Put start-code and slave-address on the bus. */
+		rc = i2c_pnx_start(addr, adap);
+		if (rc < 0)
+			break;
+
+		/* Wait for completion */
+		wait_for_completion(&alg_data->mif.complete);
+
+		if (!(rc = alg_data->mif.ret))
+			completed++;
+		dev_dbg(&adap->dev, "%s(): Complete, return code = %d.\n",
+			__FUNCTION__, rc);
+
+		/* Clear TDI and AFI bits in case they are set. */
+		if ((stat = ioread32(I2C_REG_STS(alg_data))) & mstatus_tdi) {
+			dev_dbg(&adap->dev,
+				"%s: TDI still set... clearing now.\n",
+			       adap->name);
+			iowrite32(stat, I2C_REG_STS(alg_data));
+		}
+		if ((stat = ioread32(I2C_REG_STS(alg_data))) & mstatus_afi) {
+			dev_dbg(&adap->dev,
+				"%s: AFI still set... clearing now.\n",
+			       adap->name);
+			iowrite32(stat, I2C_REG_STS(alg_data));
+		}
+	}
+
+	bus_reset_if_active(adap);
+
+	/* Cleanup to be sure... */
+	alg_data->mif.buf = NULL;
+	alg_data->mif.len = 0;
+
+	dev_dbg(&adap->dev, "%s(): exiting, stat = %x\n",
+		__FUNCTION__, ioread32(I2C_REG_STS(alg_data)));
+
+	if (completed != num)
+		return ((rc < 0) ? rc : -EREMOTEIO);
+
+	return num;
+}
+
+static u32 i2c_pnx_func(struct i2c_adapter *adapter)
+{
+	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+}
+
+static struct i2c_algorithm pnx_algorithm = {
+	.master_xfer = i2c_pnx_xfer,
+	.functionality = i2c_pnx_func,
+};
+
+static int i2c_pnx_controller_suspend(struct platform_device *pdev,
+				      pm_message_t state)
+{
+	struct i2c_pnx_data *i2c_pnx = platform_get_drvdata(pdev);
+	return i2c_pnx->suspend(pdev, state);
+}
+
+static int i2c_pnx_controller_resume(struct platform_device *pdev)
+{
+	struct i2c_pnx_data *i2c_pnx = platform_get_drvdata(pdev);
+	return i2c_pnx->resume(pdev);
+}
+
+static int __devinit i2c_pnx_probe(struct platform_device *pdev)
+{
+	unsigned long tmp;
+	int ret = 0;
+	struct i2c_pnx_algo_data *alg_data;
+	int freq_mhz;
+	struct i2c_pnx_data *i2c_pnx = pdev->dev.platform_data;
+
+	if (!i2c_pnx || !i2c_pnx->adapter) {
+		dev_err(&pdev->dev, "%s: no platform data supplied\n",
+		       __FUNCTION__);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	platform_set_drvdata(pdev, i2c_pnx);
+
+	if (i2c_pnx->calculate_input_freq)
+		freq_mhz = i2c_pnx->calculate_input_freq(pdev);
+	else {
+		freq_mhz = PNX_DEFAULT_FREQ;
+		dev_info(&pdev->dev, "Setting bus frequency to default value: "
+		       "%d MHz", freq_mhz);
+	}
+
+	i2c_pnx->adapter->algo = &pnx_algorithm;
+
+	alg_data = i2c_pnx->adapter->algo_data;
+	init_timer(&alg_data->mif.timer);
+	alg_data->mif.timer.function = i2c_pnx_timeout;
+	alg_data->mif.timer.data = (unsigned long)i2c_pnx->adapter;
+
+	/* Register I/O resource */
+	if (!request_region(alg_data->base, I2C_PNX_REGION_SIZE, pdev->name)) {
+		dev_err(&pdev->dev,
+		       "I/O region 0x%08x for I2C already in use.\n",
+		       alg_data->base);
+		ret = -ENODEV;
+		goto out_drvdata;
+	}
+
+	if (!(alg_data->ioaddr =
+			(u32)ioremap(alg_data->base, I2C_PNX_REGION_SIZE))) {
+		dev_err(&pdev->dev, "Couldn't ioremap I2C I/O region\n");
+		ret = -ENOMEM;
+		goto out_release;
+	}
+
+	i2c_pnx->set_clock_run(pdev);
+
+	/*
+	 * Clock Divisor High This value is the number of system clocks
+	 * the serial clock (SCL) will be high.
+	 * For example, if the system clock period is 50 ns and the maximum
+	 * desired serial period is 10000 ns (100 kHz), then CLKHI would be
+	 * set to 0.5*(f_sys/f_i2c)-2=0.5*(20e6/100e3)-2=98. The actual value
+	 * programmed into CLKHI will vary from this slightly due to
+	 * variations in the output pad's rise and fall times as well as
+	 * the deglitching filter length.
+	 */
+
+	tmp = ((freq_mhz * 1000) / I2C_PNX_SPEED_KHZ) / 2 - 2;
+	iowrite32(tmp, I2C_REG_CKH(alg_data));
+	iowrite32(tmp, I2C_REG_CKL(alg_data));
+
+	iowrite32(mcntrl_reset, I2C_REG_CTL(alg_data));
+	if (wait_reset(I2C_PNX_TIMEOUT, alg_data)) {
+		ret = -ENODEV;
+		goto out_unmap;
+	}
+	init_completion(&alg_data->mif.complete);
+
+	ret = request_irq(alg_data->irq, i2c_pnx_interrupt,
+			0, pdev->name, i2c_pnx->adapter);
+	if (ret)
+		goto out_clock;
+
+	/* Register this adapter with the I2C subsystem */
+	i2c_pnx->adapter->dev.parent = &pdev->dev;
+	ret = i2c_add_adapter(i2c_pnx->adapter);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "I2C: Failed to add bus\n");
+		goto out_irq;
+	}
+
+	dev_dbg(&pdev->dev, "%s: Master at %#8x, irq %d.\n",
+	       i2c_pnx->adapter->name, alg_data->base, alg_data->irq);
+
+	return 0;
+
+out_irq:
+	free_irq(alg_data->irq, alg_data);
+out_clock:
+	i2c_pnx->set_clock_stop(pdev);
+out_unmap:
+	iounmap((void *)alg_data->ioaddr);
+out_release:
+	release_region(alg_data->base, I2C_PNX_REGION_SIZE);
+out_drvdata:
+	platform_set_drvdata(pdev, NULL);
+out:
+	return ret;
+}
+
+static int __devexit i2c_pnx_remove(struct platform_device *pdev)
+{
+	struct i2c_pnx_data *i2c_pnx = platform_get_drvdata(pdev);
+	struct i2c_adapter *adap = i2c_pnx->adapter;
+	struct i2c_pnx_algo_data *alg_data = adap->algo_data;
+
+	free_irq(alg_data->irq, alg_data);
+	i2c_del_adapter(adap);
+	i2c_pnx->set_clock_stop(pdev);
+	iounmap((void *)alg_data->ioaddr);
+	release_region(alg_data->base, I2C_PNX_REGION_SIZE);
+	platform_set_drvdata(pdev, NULL);
+
+	return 0;
+}
+
+static struct platform_driver i2c_pnx_driver = {
+	.driver = {
+		.name = "pnx-i2c",
+		.owner = THIS_MODULE,
+	},
+	.probe = i2c_pnx_probe,
+	.remove = __devexit_p(i2c_pnx_remove),
+	.suspend = i2c_pnx_controller_suspend,
+	.resume = i2c_pnx_controller_resume,
+};
+
+static int __init i2c_adap_pnx_init(void)
+{
+	return platform_driver_register(&i2c_pnx_driver);
+}
+
+static void __exit i2c_adap_pnx_exit(void)
+{
+	platform_driver_unregister(&i2c_pnx_driver);
+}
+
+MODULE_AUTHOR("Vitaly Wool, Dennis Kovalev <source@mvista.com>");
+MODULE_DESCRIPTION("I2C driver for Philips IP3204-based I2C busses");
+MODULE_LICENSE("GPL");
+
+#ifdef CONFIG_I2C_PNX_EARLY
+/* We need to make sure I2C is initialized before USB */
+subsys_initcall(i2c_adap_pnx_init);
+#else
+mudule_init(i2c_adap_pnx_init);
+#endif
+module_exit(i2c_adap_pnx_exit);