drivers/i2c/lpc32xx_i2c.c - github/trini/u-boot - Gitiles

 // SPDX-License-Identifier: GPL-2.0+
 /*
  * LPC32xx I2C interface driver
  *
  * (C) Copyright 2014-2015  DENX Software Engineering GmbH
  * Written-by: Albert ARIBAUD - 3ADEV <albert.aribaud@3adev.fr>
  */

 #include <common.h>
 #include <log.h>
 #include <asm/io.h>
 #include <i2c.h>
 #include <linux/errno.h>
 #include <asm/arch/clk.h>
 #include <asm/arch/i2c.h>
 #include <dm.h>
 #include <mapmem.h>

 /*
  * Provide default speed and slave if target did not
  */

 #if !defined(CONFIG_SYS_I2C_LPC32XX_SPEED)
 #define CONFIG_SYS_I2C_LPC32XX_SPEED 350000
 #endif

 #if !defined(CONFIG_SYS_I2C_LPC32XX_SLAVE)
 #define CONFIG_SYS_I2C_LPC32XX_SLAVE 0
 #endif

 /* TX register fields */
 #define LPC32XX_I2C_TX_START		0x00000100
 #define LPC32XX_I2C_TX_STOP		0x00000200

 /* Control register values */
 #define LPC32XX_I2C_SOFT_RESET		0x00000100

 /* Status register values */
 #define LPC32XX_I2C_STAT_TFF		0x00000400
 #define LPC32XX_I2C_STAT_RFE		0x00000200
 #define LPC32XX_I2C_STAT_DRMI		0x00000008
 #define LPC32XX_I2C_STAT_NAI		0x00000004
 #define LPC32XX_I2C_STAT_TDI		0x00000001

 #ifndef CONFIG_DM_I2C
 static struct lpc32xx_i2c_base *lpc32xx_i2c[] = {
 	(struct lpc32xx_i2c_base *)I2C1_BASE,
 	(struct lpc32xx_i2c_base *)I2C2_BASE,
 	(struct lpc32xx_i2c_base *)(USB_BASE + 0x300)
 };
 #endif

 /* Set I2C bus speed */
 static unsigned int __i2c_set_bus_speed(struct lpc32xx_i2c_base *base,
 					unsigned int speed, unsigned int chip)
 {
 	int half_period;

 	if (speed == 0)
 		return -EINVAL;

 	/* OTG I2C clock source and CLK registers are different */
 	if (chip == 2) {
 		half_period = (get_periph_clk_rate() / speed) / 2;
 		if (half_period > 0xFF)
 			return -EINVAL;
 	} else {
 		half_period = (get_hclk_clk_rate() / speed) / 2;
 		if (half_period > 0x3FF)
 			return -EINVAL;
 	}

 	writel(half_period, &base->clk_hi);
 	writel(half_period, &base->clk_lo);
 	return 0;
 }

 /* I2C init called by cmd_i2c when doing 'i2c reset'. */
 static void __i2c_init(struct lpc32xx_i2c_base *base,
 		       int requested_speed, int slaveadd, unsigned int chip)
 {
 	/* soft reset (auto-clears) */
 	writel(LPC32XX_I2C_SOFT_RESET, &base->ctrl);
 	/* set HI and LO periods for half of the default speed */
 	__i2c_set_bus_speed(base, requested_speed, chip);
 }

 /* I2C probe called by cmd_i2c when doing 'i2c probe'. */
 static int __i2c_probe_chip(struct lpc32xx_i2c_base *base, u8 dev)
 {
 	int stat;

 	/* Soft-reset the controller */
 	writel(LPC32XX_I2C_SOFT_RESET, &base->ctrl);
 	while (readl(&base->ctrl) & LPC32XX_I2C_SOFT_RESET)
 		;
 	/* Addre slave for write with start before and stop after */
 	writel((dev<<1) | LPC32XX_I2C_TX_START | LPC32XX_I2C_TX_STOP,
 	       &base->tx);
 	/* wait for end of transation */
 	while (!((stat = readl(&base->stat)) & LPC32XX_I2C_STAT_TDI))
 		;
 	/* was there no acknowledge? */
 	return (stat & LPC32XX_I2C_STAT_NAI) ? -1 : 0;
 }

 /*
  * I2C read called by cmd_i2c when doing 'i2c read' and by cmd_eeprom.c
  * Begin write, send address byte(s), begin read, receive data bytes, end.
  */
 static int __i2c_read(struct lpc32xx_i2c_base *base, u8 dev, uint addr,
 		      int alen, u8 *data, int length)
 {
 	int stat, wlen;

 	/* Soft-reset the controller */
 	writel(LPC32XX_I2C_SOFT_RESET, &base->ctrl);
 	while (readl(&base->ctrl) & LPC32XX_I2C_SOFT_RESET)
 		;
 	/* do we need to write an address at all? */
 	if (alen) {
 		/* Address slave in write mode */
 		writel((dev<<1) | LPC32XX_I2C_TX_START, &base->tx);
 		/* write address bytes */
 		while (alen--) {
 			/* compute address byte + stop for the last one */
 			int a = (addr >> (8 * alen)) & 0xff;
 			if (!alen)
 				a |= LPC32XX_I2C_TX_STOP;
 			/* Send address byte */
 			writel(a, &base->tx);
 		}
 		/* wait for end of transation */
 		while (!((stat = readl(&base->stat)) & LPC32XX_I2C_STAT_TDI))
 			;
 		/* clear end-of-transaction flag */
 		writel(1, &base->stat);
 	}
 	/* do we have to read data at all? */
 	if (length) {
 		/* Address slave in read mode */
 		writel(1 | (dev<<1) | LPC32XX_I2C_TX_START, &base->tx);
 		wlen = length;
 		/* get data */
 		while (length | wlen) {
 			/* read status for TFF and RFE */
 			stat = readl(&base->stat);
 			/* must we, can we write a trigger byte? */
 			if ((wlen > 0)
 			   & (!(stat & LPC32XX_I2C_STAT_TFF))) {
 				wlen--;
 				/* write trigger byte + stop if last */
 				writel(wlen ? 0 :
 				LPC32XX_I2C_TX_STOP, &base->tx);
 			}
 			/* must we, can we read a data byte? */
 			if ((length > 0)
 			   & (!(stat & LPC32XX_I2C_STAT_RFE))) {
 				length--;
 				/* read byte */
 				*(data++) = readl(&base->rx);
 			}
 		}
 		/* wait for end of transation */
 		while (!((stat = readl(&base->stat)) & LPC32XX_I2C_STAT_TDI))
 			;
 		/* clear end-of-transaction flag */
 		writel(1, &base->stat);
 	}
 	/* success */
 	return 0;
 }

 /*
  * I2C write called by cmd_i2c when doing 'i2c write' and by cmd_eeprom.c
  * Begin write, send address byte(s), send data bytes, end.
  */
 static int __i2c_write(struct lpc32xx_i2c_base *base, u8 dev, uint addr,
 		       int alen, u8 *data, int length)
 {
 	int stat;

 	/* Soft-reset the controller */
 	writel(LPC32XX_I2C_SOFT_RESET, &base->ctrl);
 	while (readl(&base->ctrl) & LPC32XX_I2C_SOFT_RESET)
 		;
 	/* do we need to write anything at all? */
 	if (alen | length)
 		/* Address slave in write mode */
 		writel((dev<<1) | LPC32XX_I2C_TX_START, &base->tx);
 	else
 		return 0;
 	/* write address bytes */
 	while (alen) {
 		/* wait for transmit fifo not full */
 		stat = readl(&base->stat);
 		if (!(stat & LPC32XX_I2C_STAT_TFF)) {
 			alen--;
 			int a = (addr >> (8 * alen)) & 0xff;
 			if (!(alen | length))
 				a |= LPC32XX_I2C_TX_STOP;
 			/* Send address byte */
 			writel(a, &base->tx);
 		}
 	}
 	while (length) {
 		/* wait for transmit fifo not full */
 		stat = readl(&base->stat);
 		if (!(stat & LPC32XX_I2C_STAT_TFF)) {
 			/* compute data byte, add stop if length==0 */
 			length--;
 			int d = *(data++);
 			if (!length)
 				d |= LPC32XX_I2C_TX_STOP;
 			/* Send data byte */
 			writel(d, &base->tx);
 		}
 	}
 	/* wait for end of transation */
 	while (!((stat = readl(&base->stat)) & LPC32XX_I2C_STAT_TDI))
 		;
 	/* clear end-of-transaction flag */
 	writel(1, &base->stat);
 	return 0;
 }

 #ifndef CONFIG_DM_I2C
 static void lpc32xx_i2c_init(struct i2c_adapter *adap,
 			     int requested_speed, int slaveadd)
 {
 	__i2c_init(lpc32xx_i2c[adap->hwadapnr], requested_speed, slaveadd,
 		   adap->hwadapnr);
 }

 static int lpc32xx_i2c_probe_chip(struct i2c_adapter *adap, u8 dev)
 {
 	return __i2c_probe_chip(lpc32xx_i2c[adap->hwadapnr], dev);
 }

 static int lpc32xx_i2c_read(struct i2c_adapter *adap, u8 dev, uint addr,
 			    int alen, u8 *data, int length)
 {
 	return __i2c_read(lpc32xx_i2c[adap->hwadapnr], dev, addr,
 			 alen, data, length);
 }

 static int lpc32xx_i2c_write(struct i2c_adapter *adap, u8 dev, uint addr,
 			     int alen, u8 *data, int length)
 {
 	return __i2c_write(lpc32xx_i2c[adap->hwadapnr], dev, addr,
 			  alen, data, length);
 }

 static unsigned int lpc32xx_i2c_set_bus_speed(struct i2c_adapter *adap,
 					      unsigned int speed)
 {
 	return __i2c_set_bus_speed(lpc32xx_i2c[adap->hwadapnr], speed,
 				  adap->hwadapnr);
 }

 U_BOOT_I2C_ADAP_COMPLETE(lpc32xx_0, lpc32xx_i2c_init, lpc32xx_i2c_probe_chip,
 			 lpc32xx_i2c_read, lpc32xx_i2c_write,
 			 lpc32xx_i2c_set_bus_speed,
 			 CONFIG_SYS_I2C_LPC32XX_SPEED,
 			 CONFIG_SYS_I2C_LPC32XX_SLAVE,
 			 0)

 U_BOOT_I2C_ADAP_COMPLETE(lpc32xx_1, lpc32xx_i2c_init, lpc32xx_i2c_probe_chip,
 			 lpc32xx_i2c_read, lpc32xx_i2c_write,
 			 lpc32xx_i2c_set_bus_speed,
 			 CONFIG_SYS_I2C_LPC32XX_SPEED,
 			 CONFIG_SYS_I2C_LPC32XX_SLAVE,
 			 1)

 U_BOOT_I2C_ADAP_COMPLETE(lpc32xx_2, lpc32xx_i2c_init, NULL,
 			 lpc32xx_i2c_read, lpc32xx_i2c_write,
 			 lpc32xx_i2c_set_bus_speed,
 			 100000,
 			 0,
 			 2)
 #else /* CONFIG_DM_I2C */
 static int lpc32xx_i2c_probe(struct udevice *bus)
 {
 	struct lpc32xx_i2c_dev *dev = dev_get_plat(bus);
 	bus->seq = dev->index;

 	__i2c_init(dev->base, dev->speed, 0, dev->index);
 	return 0;
 }

 static int lpc32xx_i2c_probe_chip(struct udevice *bus, u32 chip_addr,
 				  u32 chip_flags)
 {
 	struct lpc32xx_i2c_dev *dev = dev_get_plat(bus);
 	return __i2c_probe_chip(dev->base, chip_addr);
 }

 static int lpc32xx_i2c_xfer(struct udevice *bus, struct i2c_msg *msg,
 		int nmsgs)
 {
 	struct lpc32xx_i2c_dev *dev = dev_get_plat(bus);
 	struct i2c_msg *dmsg, *omsg, dummy;
 	uint i = 0, address = 0;

 	memset(&dummy, 0, sizeof(struct i2c_msg));

 	/* We expect either two messages (one with an offset and one with the
 	 * actual data) or one message (just data)
 	 */
 	if (nmsgs > 2 || nmsgs == 0) {
 		debug("%s: Only one or two messages are supported.", __func__);
 		return -1;
 	}

 	omsg = nmsgs == 1 ? &dummy : msg;
 	dmsg = nmsgs == 1 ? msg : msg + 1;

 	/* the address is expected to be a uint, not a array. */
 	address = omsg->buf[0];
 	for (i = 1; i < omsg->len; i++)
 		address = (address << 8) + omsg->buf[i];

 	if (dmsg->flags & I2C_M_RD)
 		return __i2c_read(dev->base, dmsg->addr, address,
 				  omsg->len, dmsg->buf, dmsg->len);
 	else
 		return __i2c_write(dev->base, dmsg->addr, address,
 				   omsg->len, dmsg->buf, dmsg->len);
 }

 static int lpc32xx_i2c_set_bus_speed(struct udevice *bus, unsigned int speed)
 {
 	struct lpc32xx_i2c_dev *dev = dev_get_plat(bus);
 	return __i2c_set_bus_speed(dev->base, speed, dev->index);
 }

 static int lpc32xx_i2c_reset(struct udevice *bus)
 {
 	struct lpc32xx_i2c_dev *dev = dev_get_plat(bus);

 	__i2c_init(dev->base, dev->speed, 0, dev->index);
 	return 0;
 }

 static const struct dm_i2c_ops lpc32xx_i2c_ops = {
 	.xfer          = lpc32xx_i2c_xfer,
 	.probe_chip    = lpc32xx_i2c_probe_chip,
 	.deblock       = lpc32xx_i2c_reset,
 	.set_bus_speed = lpc32xx_i2c_set_bus_speed,
 };

 U_BOOT_DRIVER(i2c_lpc32xx) = {
 	.id                   = UCLASS_I2C,
 	.name                 = "i2c_lpc32xx",
 	.probe                = lpc32xx_i2c_probe,
 	.ops                  = &lpc32xx_i2c_ops,
 };
 #endif /* CONFIG_DM_I2C */
	// SPDX-License-Identifier: GPL-2.0+
	/*
	* LPC32xx I2C interface driver
	*
	* (C) Copyright 2014-2015 DENX Software Engineering GmbH
	* Written-by: Albert ARIBAUD - 3ADEV <albert.aribaud@3adev.fr>
	*/

	#include <common.h>
	#include <log.h>
	#include <asm/io.h>
	#include <i2c.h>
	#include <linux/errno.h>
	#include <asm/arch/clk.h>
	#include <asm/arch/i2c.h>
	#include <dm.h>
	#include <mapmem.h>

	/*
	* Provide default speed and slave if target did not
	*/

	#if !defined(CONFIG_SYS_I2C_LPC32XX_SPEED)
	#define CONFIG_SYS_I2C_LPC32XX_SPEED 350000
	#endif

	#if !defined(CONFIG_SYS_I2C_LPC32XX_SLAVE)
	#define CONFIG_SYS_I2C_LPC32XX_SLAVE 0
	#endif

	/* TX register fields */
	#define LPC32XX_I2C_TX_START 0x00000100
	#define LPC32XX_I2C_TX_STOP 0x00000200

	/* Control register values */
	#define LPC32XX_I2C_SOFT_RESET 0x00000100

	/* Status register values */
	#define LPC32XX_I2C_STAT_TFF 0x00000400
	#define LPC32XX_I2C_STAT_RFE 0x00000200
	#define LPC32XX_I2C_STAT_DRMI 0x00000008
	#define LPC32XX_I2C_STAT_NAI 0x00000004
	#define LPC32XX_I2C_STAT_TDI 0x00000001

	#ifndef CONFIG_DM_I2C
	static struct lpc32xx_i2c_base *lpc32xx_i2c[] = {
	(struct lpc32xx_i2c_base *)I2C1_BASE,
	(struct lpc32xx_i2c_base *)I2C2_BASE,
	(struct lpc32xx_i2c_base *)(USB_BASE + 0x300)
	};
	#endif

	/* Set I2C bus speed */
	static unsigned int __i2c_set_bus_speed(struct lpc32xx_i2c_base *base,
	unsigned int speed, unsigned int chip)
	{
	int half_period;

	if (speed == 0)
	return -EINVAL;

	/* OTG I2C clock source and CLK registers are different */
	if (chip == 2) {
	half_period = (get_periph_clk_rate() / speed) / 2;
	if (half_period > 0xFF)
	return -EINVAL;
	} else {
	half_period = (get_hclk_clk_rate() / speed) / 2;
	if (half_period > 0x3FF)
	return -EINVAL;
	}

	writel(half_period, &base->clk_hi);
	writel(half_period, &base->clk_lo);
	return 0;
	}

	/* I2C init called by cmd_i2c when doing 'i2c reset'. */
	static void __i2c_init(struct lpc32xx_i2c_base *base,
	int requested_speed, int slaveadd, unsigned int chip)
	{
	/* soft reset (auto-clears) */
	writel(LPC32XX_I2C_SOFT_RESET, &base->ctrl);
	/* set HI and LO periods for half of the default speed */
	__i2c_set_bus_speed(base, requested_speed, chip);
	}

	/* I2C probe called by cmd_i2c when doing 'i2c probe'. */
	static int __i2c_probe_chip(struct lpc32xx_i2c_base *base, u8 dev)
	{
	int stat;

	/* Soft-reset the controller */
	writel(LPC32XX_I2C_SOFT_RESET, &base->ctrl);
	while (readl(&base->ctrl) & LPC32XX_I2C_SOFT_RESET)
	;
	/* Addre slave for write with start before and stop after */
	writel((dev<<1) \| LPC32XX_I2C_TX_START \| LPC32XX_I2C_TX_STOP,
	&base->tx);
	/* wait for end of transation */
	while (!((stat = readl(&base->stat)) & LPC32XX_I2C_STAT_TDI))
	;
	/* was there no acknowledge? */
	return (stat & LPC32XX_I2C_STAT_NAI) ? -1 : 0;
	}

	/*
	* I2C read called by cmd_i2c when doing 'i2c read' and by cmd_eeprom.c
	* Begin write, send address byte(s), begin read, receive data bytes, end.
	*/
	static int __i2c_read(struct lpc32xx_i2c_base *base, u8 dev, uint addr,
	int alen, u8 *data, int length)
	{
	int stat, wlen;

	/* Soft-reset the controller */
	writel(LPC32XX_I2C_SOFT_RESET, &base->ctrl);
	while (readl(&base->ctrl) & LPC32XX_I2C_SOFT_RESET)
	;
	/* do we need to write an address at all? */
	if (alen) {
	/* Address slave in write mode */
	writel((dev<<1) \| LPC32XX_I2C_TX_START, &base->tx);
	/* write address bytes */
	while (alen--) {
	/* compute address byte + stop for the last one */
	int a = (addr >> (8 * alen)) & 0xff;
	if (!alen)
	a \|= LPC32XX_I2C_TX_STOP;
	/* Send address byte */
	writel(a, &base->tx);
	}
	/* wait for end of transation */
	while (!((stat = readl(&base->stat)) & LPC32XX_I2C_STAT_TDI))
	;
	/* clear end-of-transaction flag */
	writel(1, &base->stat);
	}
	/* do we have to read data at all? */
	if (length) {
	/* Address slave in read mode */
	writel(1 \| (dev<<1) \| LPC32XX_I2C_TX_START, &base->tx);
	wlen = length;
	/* get data */
	while (length \| wlen) {
	/* read status for TFF and RFE */
	stat = readl(&base->stat);
	/* must we, can we write a trigger byte? */
	if ((wlen > 0)
	& (!(stat & LPC32XX_I2C_STAT_TFF))) {
	wlen--;
	/* write trigger byte + stop if last */
	writel(wlen ? 0 :
	LPC32XX_I2C_TX_STOP, &base->tx);
	}
	/* must we, can we read a data byte? */
	if ((length > 0)
	& (!(stat & LPC32XX_I2C_STAT_RFE))) {
	length--;
	/* read byte */
	*(data++) = readl(&base->rx);
	}
	}
	/* wait for end of transation */
	while (!((stat = readl(&base->stat)) & LPC32XX_I2C_STAT_TDI))
	;
	/* clear end-of-transaction flag */
	writel(1, &base->stat);
	}
	/* success */
	return 0;
	}

	/*
	* I2C write called by cmd_i2c when doing 'i2c write' and by cmd_eeprom.c
	* Begin write, send address byte(s), send data bytes, end.
	*/
	static int __i2c_write(struct lpc32xx_i2c_base *base, u8 dev, uint addr,
	int alen, u8 *data, int length)
	{
	int stat;

	/* Soft-reset the controller */
	writel(LPC32XX_I2C_SOFT_RESET, &base->ctrl);
	while (readl(&base->ctrl) & LPC32XX_I2C_SOFT_RESET)
	;
	/* do we need to write anything at all? */
	if (alen \| length)
	/* Address slave in write mode */
	writel((dev<<1) \| LPC32XX_I2C_TX_START, &base->tx);
	else
	return 0;
	/* write address bytes */
	while (alen) {
	/* wait for transmit fifo not full */
	stat = readl(&base->stat);
	if (!(stat & LPC32XX_I2C_STAT_TFF)) {
	alen--;
	int a = (addr >> (8 * alen)) & 0xff;
	if (!(alen \| length))
	a \|= LPC32XX_I2C_TX_STOP;
	/* Send address byte */
	writel(a, &base->tx);
	}
	}
	while (length) {
	/* wait for transmit fifo not full */
	stat = readl(&base->stat);
	if (!(stat & LPC32XX_I2C_STAT_TFF)) {
	/* compute data byte, add stop if length==0 */
	length--;
	int d = *(data++);
	if (!length)
	d \|= LPC32XX_I2C_TX_STOP;
	/* Send data byte */
	writel(d, &base->tx);
	}
	}
	/* wait for end of transation */
	while (!((stat = readl(&base->stat)) & LPC32XX_I2C_STAT_TDI))
	;
	/* clear end-of-transaction flag */
	writel(1, &base->stat);
	return 0;
	}

	#ifndef CONFIG_DM_I2C
	static void lpc32xx_i2c_init(struct i2c_adapter *adap,
	int requested_speed, int slaveadd)
	{
	__i2c_init(lpc32xx_i2c[adap->hwadapnr], requested_speed, slaveadd,
	adap->hwadapnr);
	}

	static int lpc32xx_i2c_probe_chip(struct i2c_adapter *adap, u8 dev)
	{
	return __i2c_probe_chip(lpc32xx_i2c[adap->hwadapnr], dev);
	}

	static int lpc32xx_i2c_read(struct i2c_adapter *adap, u8 dev, uint addr,
	int alen, u8 *data, int length)
	{
	return __i2c_read(lpc32xx_i2c[adap->hwadapnr], dev, addr,
	alen, data, length);
	}

	static int lpc32xx_i2c_write(struct i2c_adapter *adap, u8 dev, uint addr,
	int alen, u8 *data, int length)
	{
	return __i2c_write(lpc32xx_i2c[adap->hwadapnr], dev, addr,
	alen, data, length);
	}

	static unsigned int lpc32xx_i2c_set_bus_speed(struct i2c_adapter *adap,
	unsigned int speed)
	{
	return __i2c_set_bus_speed(lpc32xx_i2c[adap->hwadapnr], speed,
	adap->hwadapnr);
	}

	U_BOOT_I2C_ADAP_COMPLETE(lpc32xx_0, lpc32xx_i2c_init, lpc32xx_i2c_probe_chip,
	lpc32xx_i2c_read, lpc32xx_i2c_write,
	lpc32xx_i2c_set_bus_speed,
	CONFIG_SYS_I2C_LPC32XX_SPEED,
	CONFIG_SYS_I2C_LPC32XX_SLAVE,
	0)

	U_BOOT_I2C_ADAP_COMPLETE(lpc32xx_1, lpc32xx_i2c_init, lpc32xx_i2c_probe_chip,
	lpc32xx_i2c_read, lpc32xx_i2c_write,
	lpc32xx_i2c_set_bus_speed,
	CONFIG_SYS_I2C_LPC32XX_SPEED,
	CONFIG_SYS_I2C_LPC32XX_SLAVE,
	1)

	U_BOOT_I2C_ADAP_COMPLETE(lpc32xx_2, lpc32xx_i2c_init, NULL,
	lpc32xx_i2c_read, lpc32xx_i2c_write,
	lpc32xx_i2c_set_bus_speed,
	100000,
	0,
	2)
	#else /* CONFIG_DM_I2C */
	static int lpc32xx_i2c_probe(struct udevice *bus)
	{
	struct lpc32xx_i2c_dev *dev = dev_get_plat(bus);
	bus->seq = dev->index;

	__i2c_init(dev->base, dev->speed, 0, dev->index);
	return 0;
	}

	static int lpc32xx_i2c_probe_chip(struct udevice *bus, u32 chip_addr,
	u32 chip_flags)
	{
	struct lpc32xx_i2c_dev *dev = dev_get_plat(bus);
	return __i2c_probe_chip(dev->base, chip_addr);
	}

	static int lpc32xx_i2c_xfer(struct udevice bus, struct i2c_msg msg,
	int nmsgs)
	{
	struct lpc32xx_i2c_dev *dev = dev_get_plat(bus);
	struct i2c_msg dmsg, omsg, dummy;
	uint i = 0, address = 0;

	memset(&dummy, 0, sizeof(struct i2c_msg));

	/* We expect either two messages (one with an offset and one with the
	* actual data) or one message (just data)
	*/
	if (nmsgs > 2 \|\| nmsgs == 0) {
	debug("%s: Only one or two messages are supported.", __func__);
	return -1;
	}

	omsg = nmsgs == 1 ? &dummy : msg;
	dmsg = nmsgs == 1 ? msg : msg + 1;

	/* the address is expected to be a uint, not a array. */
	address = omsg->buf[0];
	for (i = 1; i < omsg->len; i++)
	address = (address << 8) + omsg->buf[i];

	if (dmsg->flags & I2C_M_RD)
	return __i2c_read(dev->base, dmsg->addr, address,
	omsg->len, dmsg->buf, dmsg->len);
	else
	return __i2c_write(dev->base, dmsg->addr, address,
	omsg->len, dmsg->buf, dmsg->len);
	}

	static int lpc32xx_i2c_set_bus_speed(struct udevice *bus, unsigned int speed)
	{
	struct lpc32xx_i2c_dev *dev = dev_get_plat(bus);
	return __i2c_set_bus_speed(dev->base, speed, dev->index);
	}

	static int lpc32xx_i2c_reset(struct udevice *bus)
	{
	struct lpc32xx_i2c_dev *dev = dev_get_plat(bus);

	__i2c_init(dev->base, dev->speed, 0, dev->index);
	return 0;
	}

	static const struct dm_i2c_ops lpc32xx_i2c_ops = {
	.xfer = lpc32xx_i2c_xfer,
	.probe_chip = lpc32xx_i2c_probe_chip,
	.deblock = lpc32xx_i2c_reset,
	.set_bus_speed = lpc32xx_i2c_set_bus_speed,
	};

	U_BOOT_DRIVER(i2c_lpc32xx) = {
	.id = UCLASS_I2C,
	.name = "i2c_lpc32xx",
	.probe = lpc32xx_i2c_probe,
	.ops = &lpc32xx_i2c_ops,
	};
	#endif /* CONFIG_DM_I2C */