Merge branch 'for-linus/2639/i2c-1' of git://git.fluff.org/bjdooks/linux

* 'for-linus/2639/i2c-1' of git://git.fluff.org/bjdooks/linux:
i2c-mpc: Add support for 64bit system
i2c: add driver for Freescale i.MX28
i2c: tegra: Add i2c support

drivers/i2c/busses/Kconfig

···
 
 config I2C_MPC
 	tristate "MPC107/824x/85xx/512x/52xx/83xx/86xx"
-	depends on PPC32
+	depends on PPC
 	help
 	  If you say yes to this option, support will be included for the
 	  built-in I2C interface on the MPC107, Tsi107, MPC512x, MPC52xx,
···
 
 	  This driver can also be built as a module.  If so, the module
 	  will be called i2c-mv64xxx.
+
+config I2C_MXS
+	tristate "Freescale i.MX28 I2C interface"
+	depends on SOC_IMX28
+	help
+	  Say Y here if you want to use the I2C bus controller on
+	  the Freescale i.MX28 processors.
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called i2c-mxs.
 
 config I2C_NOMADIK
 	tristate "ST-Ericsson Nomadik/Ux500 I2C Controller"
···
 
 	  This driver can also be built as a module. If so, the module
 	  will be called i2c-stu300.
+
+config I2C_TEGRA
+	tristate "NVIDIA Tegra internal I2C controller"
+	depends on ARCH_TEGRA
+	help
+	  If you say yes to this option, support will be included for the
+	  I2C controller embedded in NVIDIA Tegra SOCs
 
 config I2C_VERSATILE
 	tristate "ARM Versatile/Realview I2C bus support"

drivers/i2c/busses/Makefile

···
 obj-$(CONFIG_I2C_IXP2000)	+= i2c-ixp2000.o
 obj-$(CONFIG_I2C_MPC)		+= i2c-mpc.o
 obj-$(CONFIG_I2C_MV64XXX)	+= i2c-mv64xxx.o
+obj-$(CONFIG_I2C_MXS)		+= i2c-mxs.o
 obj-$(CONFIG_I2C_NOMADIK)	+= i2c-nomadik.o
 obj-$(CONFIG_I2C_NUC900)	+= i2c-nuc900.o
 obj-$(CONFIG_I2C_OCORES)	+= i2c-ocores.o
···
 obj-$(CONFIG_I2C_SH_MOBILE)	+= i2c-sh_mobile.o
 obj-$(CONFIG_I2C_SIMTEC)	+= i2c-simtec.o
 obj-$(CONFIG_I2C_STU300)	+= i2c-stu300.o
+obj-$(CONFIG_I2C_TEGRA)		+= i2c-tegra.o
 obj-$(CONFIG_I2C_VERSATILE)	+= i2c-versatile.o
 obj-$(CONFIG_I2C_OCTEON)	+= i2c-octeon.o
 obj-$(CONFIG_I2C_XILINX)	+= i2c-xiic.o

drivers/i2c/busses/i2c-mxs.c

···
+/*
+ * Freescale MXS I2C bus driver
+ *
+ * Copyright (C) 2011 Wolfram Sang, Pengutronix e.K.
+ *
+ * based on a (non-working) driver which was:
+ *
+ * Copyright (C) 2009-2010 Freescale Semiconductor, Inc. All Rights Reserved.
+ *
+ * TODO: add dma-support if platform-support for it is available
+ *
+ * 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.
+ *
+ */
+
+#include <linux/slab.h>
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/completion.h>
+#include <linux/platform_device.h>
+#include <linux/jiffies.h>
+#include <linux/io.h>
+
+#include <mach/common.h>
+
+#define DRIVER_NAME "mxs-i2c"
+
+#define MXS_I2C_CTRL0		(0x00)
+#define MXS_I2C_CTRL0_SET	(0x04)
+
+#define MXS_I2C_CTRL0_SFTRST			0x80000000
+#define MXS_I2C_CTRL0_SEND_NAK_ON_LAST		0x02000000
+#define MXS_I2C_CTRL0_RETAIN_CLOCK		0x00200000
+#define MXS_I2C_CTRL0_POST_SEND_STOP		0x00100000
+#define MXS_I2C_CTRL0_PRE_SEND_START		0x00080000
+#define MXS_I2C_CTRL0_MASTER_MODE		0x00020000
+#define MXS_I2C_CTRL0_DIRECTION			0x00010000
+#define MXS_I2C_CTRL0_XFER_COUNT(v)		((v) & 0x0000FFFF)
+
+#define MXS_I2C_CTRL1		(0x40)
+#define MXS_I2C_CTRL1_SET	(0x44)
+#define MXS_I2C_CTRL1_CLR	(0x48)
+
+#define MXS_I2C_CTRL1_BUS_FREE_IRQ		0x80
+#define MXS_I2C_CTRL1_DATA_ENGINE_CMPLT_IRQ	0x40
+#define MXS_I2C_CTRL1_NO_SLAVE_ACK_IRQ		0x20
+#define MXS_I2C_CTRL1_OVERSIZE_XFER_TERM_IRQ	0x10
+#define MXS_I2C_CTRL1_EARLY_TERM_IRQ		0x08
+#define MXS_I2C_CTRL1_MASTER_LOSS_IRQ		0x04
+#define MXS_I2C_CTRL1_SLAVE_STOP_IRQ		0x02
+#define MXS_I2C_CTRL1_SLAVE_IRQ			0x01
+
+#define MXS_I2C_IRQ_MASK	(MXS_I2C_CTRL1_DATA_ENGINE_CMPLT_IRQ | \
+				 MXS_I2C_CTRL1_NO_SLAVE_ACK_IRQ | \
+				 MXS_I2C_CTRL1_EARLY_TERM_IRQ | \
+				 MXS_I2C_CTRL1_MASTER_LOSS_IRQ | \
+				 MXS_I2C_CTRL1_SLAVE_STOP_IRQ | \
+				 MXS_I2C_CTRL1_SLAVE_IRQ)
+
+#define MXS_I2C_QUEUECTRL	(0x60)
+#define MXS_I2C_QUEUECTRL_SET	(0x64)
+#define MXS_I2C_QUEUECTRL_CLR	(0x68)
+
+#define MXS_I2C_QUEUECTRL_QUEUE_RUN		0x20
+#define MXS_I2C_QUEUECTRL_PIO_QUEUE_MODE	0x04
+
+#define MXS_I2C_QUEUESTAT	(0x70)
+#define MXS_I2C_QUEUESTAT_RD_QUEUE_EMPTY        0x00002000
+
+#define MXS_I2C_QUEUECMD	(0x80)
+
+#define MXS_I2C_QUEUEDATA	(0x90)
+
+#define MXS_I2C_DATA		(0xa0)
+
+
+#define MXS_CMD_I2C_SELECT	(MXS_I2C_CTRL0_RETAIN_CLOCK |	\
+				 MXS_I2C_CTRL0_PRE_SEND_START |	\
+				 MXS_I2C_CTRL0_MASTER_MODE |	\
+				 MXS_I2C_CTRL0_DIRECTION |	\
+				 MXS_I2C_CTRL0_XFER_COUNT(1))
+
+#define MXS_CMD_I2C_WRITE	(MXS_I2C_CTRL0_PRE_SEND_START |	\
+				 MXS_I2C_CTRL0_MASTER_MODE |	\
+				 MXS_I2C_CTRL0_DIRECTION)
+
+#define MXS_CMD_I2C_READ	(MXS_I2C_CTRL0_SEND_NAK_ON_LAST | \
+				 MXS_I2C_CTRL0_MASTER_MODE)
+
+/**
+ * struct mxs_i2c_dev - per device, private MXS-I2C data
+ *
+ * @dev: driver model device node
+ * @regs: IO registers pointer
+ * @cmd_complete: completion object for transaction wait
+ * @cmd_err: error code for last transaction
+ * @adapter: i2c subsystem adapter node
+ */
+struct mxs_i2c_dev {
+	struct device *dev;
+	void __iomem *regs;
+	struct completion cmd_complete;
+	u32 cmd_err;
+	struct i2c_adapter adapter;
+};
+
+/*
+ * TODO: check if calls to here are really needed. If not, we could get rid of
+ * mxs_reset_block and the mach-dependency. Needs an I2C analyzer, probably.
+ */
+static void mxs_i2c_reset(struct mxs_i2c_dev *i2c)
+{
+	mxs_reset_block(i2c->regs);
+	writel(MXS_I2C_IRQ_MASK << 8, i2c->regs + MXS_I2C_CTRL1_SET);
+}
+
+static void mxs_i2c_pioq_setup_read(struct mxs_i2c_dev *i2c, u8 addr, int len,
+					int flags)
+{
+	u32 data;
+
+	writel(MXS_CMD_I2C_SELECT, i2c->regs + MXS_I2C_QUEUECMD);
+
+	data = (addr << 1) | I2C_SMBUS_READ;
+	writel(data, i2c->regs + MXS_I2C_DATA);
+
+	data = MXS_CMD_I2C_READ | MXS_I2C_CTRL0_XFER_COUNT(len) | flags;
+	writel(data, i2c->regs + MXS_I2C_QUEUECMD);
+}
+
+static void mxs_i2c_pioq_setup_write(struct mxs_i2c_dev *i2c,
+				    u8 addr, u8 *buf, int len, int flags)
+{
+	u32 data;
+	int i, shifts_left;
+
+	data = MXS_CMD_I2C_WRITE | MXS_I2C_CTRL0_XFER_COUNT(len + 1) | flags;
+	writel(data, i2c->regs + MXS_I2C_QUEUECMD);
+
+	/*
+	 * We have to copy the slave address (u8) and buffer (arbitrary number
+	 * of u8) into the data register (u32). To achieve that, the u8 are put
+	 * into the MSBs of 'data' which is then shifted for the next u8. When
+	 * apropriate, 'data' is written to MXS_I2C_DATA. So, the first u32
+	 * looks like this:
+	 *
+	 *  3          2          1          0
+	 * 10987654|32109876|54321098|76543210
+	 * --------+--------+--------+--------
+	 * buffer+2|buffer+1|buffer+0|slave_addr
+	 */
+
+	data = ((addr << 1) | I2C_SMBUS_WRITE) << 24;
+
+	for (i = 0; i < len; i++) {
+		data >>= 8;
+		data |= buf[i] << 24;
+		if ((i & 3) == 2)
+			writel(data, i2c->regs + MXS_I2C_DATA);
+	}
+
+	/* Write out the remaining bytes if any */
+	shifts_left = 24 - (i & 3) * 8;
+	if (shifts_left)
+		writel(data >> shifts_left, i2c->regs + MXS_I2C_DATA);
+}
+
+/*
+ * TODO: should be replaceable with a waitqueue and RD_QUEUE_IRQ (setting the
+ * rd_threshold to 1). Couldn't get this to work, though.
+ */
+static int mxs_i2c_wait_for_data(struct mxs_i2c_dev *i2c)
+{
+	unsigned long timeout = jiffies + msecs_to_jiffies(1000);
+
+	while (readl(i2c->regs + MXS_I2C_QUEUESTAT)
+			& MXS_I2C_QUEUESTAT_RD_QUEUE_EMPTY) {
+			if (time_after(jiffies, timeout))
+				return -ETIMEDOUT;
+			cond_resched();
+	}
+
+	return 0;
+}
+
+static int mxs_i2c_finish_read(struct mxs_i2c_dev *i2c, u8 *buf, int len)
+{
+	u32 data;
+	int i;
+
+	for (i = 0; i < len; i++) {
+		if ((i & 3) == 0) {
+			if (mxs_i2c_wait_for_data(i2c))
+				return -ETIMEDOUT;
+			data = readl(i2c->regs + MXS_I2C_QUEUEDATA);
+		}
+		buf[i] = data & 0xff;
+		data >>= 8;
+	}
+
+	return 0;
+}
+
+/*
+ * Low level master read/write transaction.
+ */
+static int mxs_i2c_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg,
+				int stop)
+{
+	struct mxs_i2c_dev *i2c = i2c_get_adapdata(adap);
+	int ret;
+	int flags;
+
+	init_completion(&i2c->cmd_complete);
+
+	dev_dbg(i2c->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;
+
+	flags = stop ? MXS_I2C_CTRL0_POST_SEND_STOP : 0;
+
+	if (msg->flags & I2C_M_RD)
+		mxs_i2c_pioq_setup_read(i2c, msg->addr, msg->len, flags);
+	else
+		mxs_i2c_pioq_setup_write(i2c, msg->addr, msg->buf, msg->len,
+					flags);
+
+	writel(MXS_I2C_QUEUECTRL_QUEUE_RUN,
+			i2c->regs + MXS_I2C_QUEUECTRL_SET);
+
+	ret = wait_for_completion_timeout(&i2c->cmd_complete,
+						msecs_to_jiffies(1000));
+	if (ret == 0)
+		goto timeout;
+
+	if ((!i2c->cmd_err) && (msg->flags & I2C_M_RD)) {
+		ret = mxs_i2c_finish_read(i2c, msg->buf, msg->len);
+		if (ret)
+			goto timeout;
+	}
+
+	if (i2c->cmd_err == -ENXIO)
+		mxs_i2c_reset(i2c);
+
+	dev_dbg(i2c->dev, "Done with err=%d\n", i2c->cmd_err);
+
+	return i2c->cmd_err;
+
+timeout:
+	dev_dbg(i2c->dev, "Timeout!\n");
+	mxs_i2c_reset(i2c);
+	return -ETIMEDOUT;
+}
+
+static int mxs_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[],
+			int num)
+{
+	int i;
+	int err;
+
+	for (i = 0; i < num; i++) {
+		err = mxs_i2c_xfer_msg(adap, &msgs[i], i == (num - 1));
+		if (err)
+			return err;
+	}
+
+	return num;
+}
+
+static u32 mxs_i2c_func(struct i2c_adapter *adap)
+{
+	return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
+}
+
+static irqreturn_t mxs_i2c_isr(int this_irq, void *dev_id)
+{
+	struct mxs_i2c_dev *i2c = dev_id;
+	u32 stat = readl(i2c->regs + MXS_I2C_CTRL1) & MXS_I2C_IRQ_MASK;
+
+	if (!stat)
+		return IRQ_NONE;
+
+	if (stat & MXS_I2C_CTRL1_NO_SLAVE_ACK_IRQ)
+		i2c->cmd_err = -ENXIO;
+	else if (stat & (MXS_I2C_CTRL1_EARLY_TERM_IRQ |
+		    MXS_I2C_CTRL1_MASTER_LOSS_IRQ |
+		    MXS_I2C_CTRL1_SLAVE_STOP_IRQ | MXS_I2C_CTRL1_SLAVE_IRQ))
+		/* MXS_I2C_CTRL1_OVERSIZE_XFER_TERM_IRQ is only for slaves */
+		i2c->cmd_err = -EIO;
+	else
+		i2c->cmd_err = 0;
+
+	complete(&i2c->cmd_complete);
+
+	writel(stat, i2c->regs + MXS_I2C_CTRL1_CLR);
+	return IRQ_HANDLED;
+}
+
+static const struct i2c_algorithm mxs_i2c_algo = {
+	.master_xfer = mxs_i2c_xfer,
+	.functionality = mxs_i2c_func,
+};
+
+static int __devinit mxs_i2c_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct mxs_i2c_dev *i2c;
+	struct i2c_adapter *adap;
+	struct resource *res;
+	resource_size_t res_size;
+	int err, irq;
+
+	i2c = devm_kzalloc(dev, sizeof(struct mxs_i2c_dev), GFP_KERNEL);
+	if (!i2c)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -ENOENT;
+
+	res_size = resource_size(res);
+	if (!devm_request_mem_region(dev, res->start, res_size, res->name))
+		return -EBUSY;
+
+	i2c->regs = devm_ioremap_nocache(dev, res->start, res_size);
+	if (!i2c->regs)
+		return -EBUSY;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
+	err = devm_request_irq(dev, irq, mxs_i2c_isr, 0, dev_name(dev), i2c);
+	if (err)
+		return err;
+
+	i2c->dev = dev;
+	platform_set_drvdata(pdev, i2c);
+
+	/* Do reset to enforce correct startup after pinmuxing */
+	mxs_i2c_reset(i2c);
+	writel(MXS_I2C_QUEUECTRL_PIO_QUEUE_MODE,
+			i2c->regs + MXS_I2C_QUEUECTRL_SET);
+
+	adap = &i2c->adapter;
+	strlcpy(adap->name, "MXS I2C adapter", sizeof(adap->name));
+	adap->owner = THIS_MODULE;
+	adap->algo = &mxs_i2c_algo;
+	adap->dev.parent = dev;
+	adap->nr = pdev->id;
+	i2c_set_adapdata(adap, i2c);
+	err = i2c_add_numbered_adapter(adap);
+	if (err) {
+		dev_err(dev, "Failed to add adapter (%d)\n", err);
+		writel(MXS_I2C_CTRL0_SFTRST,
+				i2c->regs + MXS_I2C_CTRL0_SET);
+		return err;
+	}
+
+	return 0;
+}
+
+static int __devexit mxs_i2c_remove(struct platform_device *pdev)
+{
+	struct mxs_i2c_dev *i2c = platform_get_drvdata(pdev);
+	int ret;
+
+	ret = i2c_del_adapter(&i2c->adapter);
+	if (ret)
+		return -EBUSY;
+
+	writel(MXS_I2C_QUEUECTRL_QUEUE_RUN,
+			i2c->regs + MXS_I2C_QUEUECTRL_CLR);
+	writel(MXS_I2C_CTRL0_SFTRST, i2c->regs + MXS_I2C_CTRL0_SET);
+
+	platform_set_drvdata(pdev, NULL);
+
+	return 0;
+}
+
+static struct platform_driver mxs_i2c_driver = {
+	.driver = {
+		   .name = DRIVER_NAME,
+		   .owner = THIS_MODULE,
+		   },
+	.remove = __devexit_p(mxs_i2c_remove),
+};
+
+static int __init mxs_i2c_init(void)
+{
+	return platform_driver_probe(&mxs_i2c_driver, mxs_i2c_probe);
+}
+subsys_initcall(mxs_i2c_init);
+
+static void __exit mxs_i2c_exit(void)
+{
+	platform_driver_unregister(&mxs_i2c_driver);
+}
+module_exit(mxs_i2c_exit);
+
+MODULE_AUTHOR("Wolfram Sang <[e-mail]>");
+MODULE_DESCRIPTION("MXS I2C Bus Driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:" DRIVER_NAME);

drivers/i2c/busses/i2c-tegra.c

···
+/*
+ * drivers/i2c/busses/i2c-tegra.c
+ *
+ * Copyright (C) 2010 Google, Inc.
+ * Author: Colin Cross <[e-mail]>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/io.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/i2c-tegra.h>
+
+#include <asm/unaligned.h>
+
+#include <mach/clk.h>
+
+#define TEGRA_I2C_TIMEOUT (msecs_to_jiffies(1000))
+#define BYTES_PER_FIFO_WORD 4
+
+#define I2C_CNFG				0x000
+#define I2C_CNFG_PACKET_MODE_EN			(1<<10)
+#define I2C_CNFG_NEW_MASTER_FSM			(1<<11)
+#define I2C_SL_CNFG				0x020
+#define I2C_SL_CNFG_NEWSL			(1<<2)
+#define I2C_SL_ADDR1				0x02c
+#define I2C_TX_FIFO				0x050
+#define I2C_RX_FIFO				0x054
+#define I2C_PACKET_TRANSFER_STATUS		0x058
+#define I2C_FIFO_CONTROL			0x05c
+#define I2C_FIFO_CONTROL_TX_FLUSH		(1<<1)
+#define I2C_FIFO_CONTROL_RX_FLUSH		(1<<0)
+#define I2C_FIFO_CONTROL_TX_TRIG_SHIFT		5
+#define I2C_FIFO_CONTROL_RX_TRIG_SHIFT		2
+#define I2C_FIFO_STATUS				0x060
+#define I2C_FIFO_STATUS_TX_MASK			0xF0
+#define I2C_FIFO_STATUS_TX_SHIFT		4
+#define I2C_FIFO_STATUS_RX_MASK			0x0F
+#define I2C_FIFO_STATUS_RX_SHIFT		0
+#define I2C_INT_MASK				0x064
+#define I2C_INT_STATUS				0x068
+#define I2C_INT_PACKET_XFER_COMPLETE		(1<<7)
+#define I2C_INT_ALL_PACKETS_XFER_COMPLETE	(1<<6)
+#define I2C_INT_TX_FIFO_OVERFLOW		(1<<5)
+#define I2C_INT_RX_FIFO_UNDERFLOW		(1<<4)
+#define I2C_INT_NO_ACK				(1<<3)
+#define I2C_INT_ARBITRATION_LOST		(1<<2)
+#define I2C_INT_TX_FIFO_DATA_REQ		(1<<1)
+#define I2C_INT_RX_FIFO_DATA_REQ		(1<<0)
+#define I2C_CLK_DIVISOR				0x06c
+
+#define DVC_CTRL_REG1				0x000
+#define DVC_CTRL_REG1_INTR_EN			(1<<10)
+#define DVC_CTRL_REG2				0x004
+#define DVC_CTRL_REG3				0x008
+#define DVC_CTRL_REG3_SW_PROG			(1<<26)
+#define DVC_CTRL_REG3_I2C_DONE_INTR_EN		(1<<30)
+#define DVC_STATUS				0x00c
+#define DVC_STATUS_I2C_DONE_INTR		(1<<30)
+
+#define I2C_ERR_NONE				0x00
+#define I2C_ERR_NO_ACK				0x01
+#define I2C_ERR_ARBITRATION_LOST		0x02
+
+#define PACKET_HEADER0_HEADER_SIZE_SHIFT	28
+#define PACKET_HEADER0_PACKET_ID_SHIFT		16
+#define PACKET_HEADER0_CONT_ID_SHIFT		12
+#define PACKET_HEADER0_PROTOCOL_I2C		(1<<4)
+
+#define I2C_HEADER_HIGHSPEED_MODE		(1<<22)
+#define I2C_HEADER_CONT_ON_NAK			(1<<21)
+#define I2C_HEADER_SEND_START_BYTE		(1<<20)
+#define I2C_HEADER_READ				(1<<19)
+#define I2C_HEADER_10BIT_ADDR			(1<<18)
+#define I2C_HEADER_IE_ENABLE			(1<<17)
+#define I2C_HEADER_REPEAT_START			(1<<16)
+#define I2C_HEADER_MASTER_ADDR_SHIFT		12
+#define I2C_HEADER_SLAVE_ADDR_SHIFT		1
+
+/**
+ * struct tegra_i2c_dev	- per device i2c context
+ * @dev: device reference for power management
+ * @adapter: core i2c layer adapter information
+ * @clk: clock reference for i2c controller
+ * @i2c_clk: clock reference for i2c bus
+ * @iomem: memory resource for registers
+ * @base: ioremapped registers cookie
+ * @cont_id: i2c controller id, used for for packet header
+ * @irq: irq number of transfer complete interrupt
+ * @is_dvc: identifies the DVC i2c controller, has a different register layout
+ * @msg_complete: transfer completion notifier
+ * @msg_err: error code for completed message
+ * @msg_buf: pointer to current message data
+ * @msg_buf_remaining: size of unsent data in the message buffer
+ * @msg_read: identifies read transfers
+ * @bus_clk_rate: current i2c bus clock rate
+ * @is_suspended: prevents i2c controller accesses after suspend is called
+ */
+struct tegra_i2c_dev {
+	struct device *dev;
+	struct i2c_adapter adapter;
+	struct clk *clk;
+	struct clk *i2c_clk;
+	struct resource *iomem;
+	void __iomem *base;
+	int cont_id;
+	int irq;
+	int is_dvc;
+	struct completion msg_complete;
+	int msg_err;
+	u8 *msg_buf;
+	size_t msg_buf_remaining;
+	int msg_read;
+	unsigned long bus_clk_rate;
+	bool is_suspended;
+};
+
+static void dvc_writel(struct tegra_i2c_dev *i2c_dev, u32 val, unsigned long reg)
+{
+	writel(val, i2c_dev->base + reg);
+}
+
+static u32 dvc_readl(struct tegra_i2c_dev *i2c_dev, unsigned long reg)
+{
+	return readl(i2c_dev->base + reg);
+}
+
+/*
+ * i2c_writel and i2c_readl will offset the register if necessary to talk
+ * to the I2C block inside the DVC block
+ */
+static unsigned long tegra_i2c_reg_addr(struct tegra_i2c_dev *i2c_dev,
+	unsigned long reg)
+{
+	if (i2c_dev->is_dvc)
+		reg += (reg >= I2C_TX_FIFO) ? 0x10 : 0x40;
+	return reg;
+}
+
+static void i2c_writel(struct tegra_i2c_dev *i2c_dev, u32 val,
+	unsigned long reg)
+{
+	writel(val, i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg));
+}
+
+static u32 i2c_readl(struct tegra_i2c_dev *i2c_dev, unsigned long reg)
+{
+	return readl(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg));
+}
+
+static void i2c_writesl(struct tegra_i2c_dev *i2c_dev, void *data,
+	unsigned long reg, int len)
+{
+	writesl(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg), data, len);
+}
+
+static void i2c_readsl(struct tegra_i2c_dev *i2c_dev, void *data,
+	unsigned long reg, int len)
+{
+	readsl(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg), data, len);
+}
+
+static void tegra_i2c_mask_irq(struct tegra_i2c_dev *i2c_dev, u32 mask)
+{
+	u32 int_mask = i2c_readl(i2c_dev, I2C_INT_MASK);
+	int_mask &= ~mask;
+	i2c_writel(i2c_dev, int_mask, I2C_INT_MASK);
+}
+
+static void tegra_i2c_unmask_irq(struct tegra_i2c_dev *i2c_dev, u32 mask)
+{
+	u32 int_mask = i2c_readl(i2c_dev, I2C_INT_MASK);
+	int_mask |= mask;
+	i2c_writel(i2c_dev, int_mask, I2C_INT_MASK);
+}
+
+static int tegra_i2c_flush_fifos(struct tegra_i2c_dev *i2c_dev)
+{
+	unsigned long timeout = jiffies + HZ;
+	u32 val = i2c_readl(i2c_dev, I2C_FIFO_CONTROL);
+	val |= I2C_FIFO_CONTROL_TX_FLUSH | I2C_FIFO_CONTROL_RX_FLUSH;
+	i2c_writel(i2c_dev, val, I2C_FIFO_CONTROL);
+
+	while (i2c_readl(i2c_dev, I2C_FIFO_CONTROL) &
+		(I2C_FIFO_CONTROL_TX_FLUSH | I2C_FIFO_CONTROL_RX_FLUSH)) {
+		if (time_after(jiffies, timeout)) {
+			dev_warn(i2c_dev->dev, "timeout waiting for fifo flush\n");
+			return -ETIMEDOUT;
+		}
+		msleep(1);
+	}
+	return 0;
+}
+
+static int tegra_i2c_empty_rx_fifo(struct tegra_i2c_dev *i2c_dev)
+{
+	u32 val;
+	int rx_fifo_avail;
+	u8 *buf = i2c_dev->msg_buf;
+	size_t buf_remaining = i2c_dev->msg_buf_remaining;
+	int words_to_transfer;
+
+	val = i2c_readl(i2c_dev, I2C_FIFO_STATUS);
+	rx_fifo_avail = (val & I2C_FIFO_STATUS_RX_MASK) >>
+		I2C_FIFO_STATUS_RX_SHIFT;
+
+	/* Rounds down to not include partial word at the end of buf */
+	words_to_transfer = buf_remaining / BYTES_PER_FIFO_WORD;
+	if (words_to_transfer > rx_fifo_avail)
+		words_to_transfer = rx_fifo_avail;
+
+	i2c_readsl(i2c_dev, buf, I2C_RX_FIFO, words_to_transfer);
+
+	buf += words_to_transfer * BYTES_PER_FIFO_WORD;
+	buf_remaining -= words_to_transfer * BYTES_PER_FIFO_WORD;
+	rx_fifo_avail -= words_to_transfer;
+
+	/*
+	 * If there is a partial word at the end of buf, handle it manually to
+	 * prevent overwriting past the end of buf
+	 */
+	if (rx_fifo_avail > 0 && buf_remaining > 0) {
+		BUG_ON(buf_remaining > 3);
+		val = i2c_readl(i2c_dev, I2C_RX_FIFO);
+		memcpy(buf, &val, buf_remaining);
+		buf_remaining = 0;
+		rx_fifo_avail--;
+	}
+
+	BUG_ON(rx_fifo_avail > 0 && buf_remaining > 0);
+	i2c_dev->msg_buf_remaining = buf_remaining;
+	i2c_dev->msg_buf = buf;
+	return 0;
+}
+
+static int tegra_i2c_fill_tx_fifo(struct tegra_i2c_dev *i2c_dev)
+{
+	u32 val;
+	int tx_fifo_avail;
+	u8 *buf = i2c_dev->msg_buf;
+	size_t buf_remaining = i2c_dev->msg_buf_remaining;
+	int words_to_transfer;
+
+	val = i2c_readl(i2c_dev, I2C_FIFO_STATUS);
+	tx_fifo_avail = (val & I2C_FIFO_STATUS_TX_MASK) >>
+		I2C_FIFO_STATUS_TX_SHIFT;
+
+	/* Rounds down to not include partial word at the end of buf */
+	words_to_transfer = buf_remaining / BYTES_PER_FIFO_WORD;
+	if (words_to_transfer > tx_fifo_avail)
+		words_to_transfer = tx_fifo_avail;
+
+	i2c_writesl(i2c_dev, buf, I2C_TX_FIFO, words_to_transfer);
+
+	buf += words_to_transfer * BYTES_PER_FIFO_WORD;
+	buf_remaining -= words_to_transfer * BYTES_PER_FIFO_WORD;
+	tx_fifo_avail -= words_to_transfer;
+
+	/*
+	 * If there is a partial word at the end of buf, handle it manually to
+	 * prevent reading past the end of buf, which could cross a page
+	 * boundary and fault.
+	 */
+	if (tx_fifo_avail > 0 && buf_remaining > 0) {
+		BUG_ON(buf_remaining > 3);
+		memcpy(&val, buf, buf_remaining);
+		i2c_writel(i2c_dev, val, I2C_TX_FIFO);
+		buf_remaining = 0;
+		tx_fifo_avail--;
+	}
+
+	BUG_ON(tx_fifo_avail > 0 && buf_remaining > 0);
+	i2c_dev->msg_buf_remaining = buf_remaining;
+	i2c_dev->msg_buf = buf;
+	return 0;
+}
+
+/*
+ * One of the Tegra I2C blocks is inside the DVC (Digital Voltage Controller)
+ * block.  This block is identical to the rest of the I2C blocks, except that
+ * it only supports master mode, it has registers moved around, and it needs
+ * some extra init to get it into I2C mode.  The register moves are handled
+ * by i2c_readl and i2c_writel
+ */
+static void tegra_dvc_init(struct tegra_i2c_dev *i2c_dev)
+{
+	u32 val = 0;
+	val = dvc_readl(i2c_dev, DVC_CTRL_REG3);
+	val |= DVC_CTRL_REG3_SW_PROG;
+	val |= DVC_CTRL_REG3_I2C_DONE_INTR_EN;
+	dvc_writel(i2c_dev, val, DVC_CTRL_REG3);
+
+	val = dvc_readl(i2c_dev, DVC_CTRL_REG1);
+	val |= DVC_CTRL_REG1_INTR_EN;
+	dvc_writel(i2c_dev, val, DVC_CTRL_REG1);
+}
+
+static int tegra_i2c_init(struct tegra_i2c_dev *i2c_dev)
+{
+	u32 val;
+	int err = 0;
+
+	clk_enable(i2c_dev->clk);
+
+	tegra_periph_reset_assert(i2c_dev->clk);
+	udelay(2);
+	tegra_periph_reset_deassert(i2c_dev->clk);
+
+	if (i2c_dev->is_dvc)
+		tegra_dvc_init(i2c_dev);
+
+	val = I2C_CNFG_NEW_MASTER_FSM | I2C_CNFG_PACKET_MODE_EN;
+	i2c_writel(i2c_dev, val, I2C_CNFG);
+	i2c_writel(i2c_dev, 0, I2C_INT_MASK);
+	clk_set_rate(i2c_dev->clk, i2c_dev->bus_clk_rate * 8);
+
+	val = 7 << I2C_FIFO_CONTROL_TX_TRIG_SHIFT |
+		0 << I2C_FIFO_CONTROL_RX_TRIG_SHIFT;
+	i2c_writel(i2c_dev, val, I2C_FIFO_CONTROL);
+
+	if (tegra_i2c_flush_fifos(i2c_dev))
+		err = -ETIMEDOUT;
+
+	clk_disable(i2c_dev->clk);
+	return err;
+}
+
+static irqreturn_t tegra_i2c_isr(int irq, void *dev_id)
+{
+	u32 status;
+	const u32 status_err = I2C_INT_NO_ACK | I2C_INT_ARBITRATION_LOST;
+	struct tegra_i2c_dev *i2c_dev = dev_id;
+
+	status = i2c_readl(i2c_dev, I2C_INT_STATUS);
+
+	if (status == 0) {
+		dev_warn(i2c_dev->dev, "interrupt with no status\n");
+		return IRQ_NONE;
+	}
+
+	if (unlikely(status & status_err)) {
+		if (status & I2C_INT_NO_ACK)
+			i2c_dev->msg_err |= I2C_ERR_NO_ACK;
+		if (status & I2C_INT_ARBITRATION_LOST)
+			i2c_dev->msg_err |= I2C_ERR_ARBITRATION_LOST;
+		complete(&i2c_dev->msg_complete);
+		goto err;
+	}
+
+	if (i2c_dev->msg_read && (status & I2C_INT_RX_FIFO_DATA_REQ)) {
+		if (i2c_dev->msg_buf_remaining)
+			tegra_i2c_empty_rx_fifo(i2c_dev);
+		else
+			BUG();
+	}
+
+	if (!i2c_dev->msg_read && (status & I2C_INT_TX_FIFO_DATA_REQ)) {
+		if (i2c_dev->msg_buf_remaining)
+			tegra_i2c_fill_tx_fifo(i2c_dev);
+		else
+			tegra_i2c_mask_irq(i2c_dev, I2C_INT_TX_FIFO_DATA_REQ);
+	}
+
+	if ((status & I2C_INT_PACKET_XFER_COMPLETE) &&
+			!i2c_dev->msg_buf_remaining)
+		complete(&i2c_dev->msg_complete);
+
+	i2c_writel(i2c_dev, status, I2C_INT_STATUS);
+	if (i2c_dev->is_dvc)
+		dvc_writel(i2c_dev, DVC_STATUS_I2C_DONE_INTR, DVC_STATUS);
+	return IRQ_HANDLED;
+err:
+	/* An error occured, mask all interrupts */
+	tegra_i2c_mask_irq(i2c_dev, I2C_INT_NO_ACK | I2C_INT_ARBITRATION_LOST |
+		I2C_INT_PACKET_XFER_COMPLETE | I2C_INT_TX_FIFO_DATA_REQ |
+		I2C_INT_RX_FIFO_DATA_REQ);
+	i2c_writel(i2c_dev, status, I2C_INT_STATUS);
+	return IRQ_HANDLED;
+}
+
+static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev,
+	struct i2c_msg *msg, int stop)
+{
+	u32 packet_header;
+	u32 int_mask;
+	int ret;
+
+	tegra_i2c_flush_fifos(i2c_dev);
+	i2c_writel(i2c_dev, 0xFF, I2C_INT_STATUS);
+
+	if (msg->len == 0)
+		return -EINVAL;
+
+	i2c_dev->msg_buf = msg->buf;
+	i2c_dev->msg_buf_remaining = msg->len;
+	i2c_dev->msg_err = I2C_ERR_NONE;
+	i2c_dev->msg_read = (msg->flags & I2C_M_RD);
+	INIT_COMPLETION(i2c_dev->msg_complete);
+
+	packet_header = (0 << PACKET_HEADER0_HEADER_SIZE_SHIFT) |
+			PACKET_HEADER0_PROTOCOL_I2C |
+			(i2c_dev->cont_id << PACKET_HEADER0_CONT_ID_SHIFT) |
+			(1 << PACKET_HEADER0_PACKET_ID_SHIFT);
+	i2c_writel(i2c_dev, packet_header, I2C_TX_FIFO);
+
+	packet_header = msg->len - 1;
+	i2c_writel(i2c_dev, packet_header, I2C_TX_FIFO);
+
+	packet_header = msg->addr << I2C_HEADER_SLAVE_ADDR_SHIFT;
+	packet_header |= I2C_HEADER_IE_ENABLE;
+	if (msg->flags & I2C_M_TEN)
+		packet_header |= I2C_HEADER_10BIT_ADDR;
+	if (msg->flags & I2C_M_IGNORE_NAK)
+		packet_header |= I2C_HEADER_CONT_ON_NAK;
+	if (msg->flags & I2C_M_NOSTART)
+		packet_header |= I2C_HEADER_REPEAT_START;
+	if (msg->flags & I2C_M_RD)
+		packet_header |= I2C_HEADER_READ;
+	i2c_writel(i2c_dev, packet_header, I2C_TX_FIFO);
+
+	if (!(msg->flags & I2C_M_RD))
+		tegra_i2c_fill_tx_fifo(i2c_dev);
+
+	int_mask = I2C_INT_NO_ACK | I2C_INT_ARBITRATION_LOST;
+	if (msg->flags & I2C_M_RD)
+		int_mask |= I2C_INT_RX_FIFO_DATA_REQ;
+	else if (i2c_dev->msg_buf_remaining)
+		int_mask |= I2C_INT_TX_FIFO_DATA_REQ;
+	tegra_i2c_unmask_irq(i2c_dev, int_mask);
+	dev_dbg(i2c_dev->dev, "unmasked irq: %02x\n",
+		i2c_readl(i2c_dev, I2C_INT_MASK));
+
+	ret = wait_for_completion_timeout(&i2c_dev->msg_complete, TEGRA_I2C_TIMEOUT);
+	tegra_i2c_mask_irq(i2c_dev, int_mask);
+
+	if (WARN_ON(ret == 0)) {
+		dev_err(i2c_dev->dev, "i2c transfer timed out\n");
+
+		tegra_i2c_init(i2c_dev);
+		return -ETIMEDOUT;
+	}
+
+	dev_dbg(i2c_dev->dev, "transfer complete: %d %d %d\n",
+		ret, completion_done(&i2c_dev->msg_complete), i2c_dev->msg_err);
+
+	if (likely(i2c_dev->msg_err == I2C_ERR_NONE))
+		return 0;
+
+	tegra_i2c_init(i2c_dev);
+	if (i2c_dev->msg_err == I2C_ERR_NO_ACK) {
+		if (msg->flags & I2C_M_IGNORE_NAK)
+			return 0;
+		return -EREMOTEIO;
+	}
+
+	return -EIO;
+}
+
+static int tegra_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[],
+	int num)
+{
+	struct tegra_i2c_dev *i2c_dev = i2c_get_adapdata(adap);
+	int i;
+	int ret = 0;
+
+	if (i2c_dev->is_suspended)
+		return -EBUSY;
+
+	clk_enable(i2c_dev->clk);
+	for (i = 0; i < num; i++) {
+		int stop = (i == (num - 1)) ? 1  : 0;
+		ret = tegra_i2c_xfer_msg(i2c_dev, &msgs[i], stop);
+		if (ret)
+			break;
+	}
+	clk_disable(i2c_dev->clk);
+	return ret ?: i;
+}
+
+static u32 tegra_i2c_func(struct i2c_adapter *adap)
+{
+	return I2C_FUNC_I2C;
+}
+
+static const struct i2c_algorithm tegra_i2c_algo = {
+	.master_xfer	= tegra_i2c_xfer,
+	.functionality	= tegra_i2c_func,
+};
+
+static int tegra_i2c_probe(struct platform_device *pdev)
+{
+	struct tegra_i2c_dev *i2c_dev;
+	struct tegra_i2c_platform_data *pdata = pdev->dev.platform_data;
+	struct resource *res;
+	struct resource *iomem;
+	struct clk *clk;
+	struct clk *i2c_clk;
+	void *base;
+	int irq;
+	int ret = 0;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(&pdev->dev, "no mem resource\n");
+		return -EINVAL;
+	}
+	iomem = request_mem_region(res->start, resource_size(res), pdev->name);
+	if (!iomem) {
+		dev_err(&pdev->dev, "I2C region already claimed\n");
+		return -EBUSY;
+	}
+
+	base = ioremap(iomem->start, resource_size(iomem));
+	if (!base) {
+		dev_err(&pdev->dev, "Cannot ioremap I2C region\n");
+		return -ENOMEM;
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
+	if (!res) {
+		dev_err(&pdev->dev, "no irq resource\n");
+		ret = -EINVAL;
+		goto err_iounmap;
+	}
+	irq = res->start;
+
+	clk = clk_get(&pdev->dev, NULL);
+	if (IS_ERR(clk)) {
+		dev_err(&pdev->dev, "missing controller clock");
+		ret = PTR_ERR(clk);
+		goto err_release_region;
+	}
+
+	i2c_clk = clk_get(&pdev->dev, "i2c");
+	if (IS_ERR(i2c_clk)) {
+		dev_err(&pdev->dev, "missing bus clock");
+		ret = PTR_ERR(i2c_clk);
+		goto err_clk_put;
+	}
+
+	i2c_dev = kzalloc(sizeof(struct tegra_i2c_dev), GFP_KERNEL);
+	if (!i2c_dev) {
+		ret = -ENOMEM;
+		goto err_i2c_clk_put;
+	}
+
+	i2c_dev->base = base;
+	i2c_dev->clk = clk;
+	i2c_dev->i2c_clk = i2c_clk;
+	i2c_dev->iomem = iomem;
+	i2c_dev->adapter.algo = &tegra_i2c_algo;
+	i2c_dev->irq = irq;
+	i2c_dev->cont_id = pdev->id;
+	i2c_dev->dev = &pdev->dev;
+	i2c_dev->bus_clk_rate = pdata ? pdata->bus_clk_rate : 100000;
+
+	if (pdev->id == 3)
+		i2c_dev->is_dvc = 1;
+	init_completion(&i2c_dev->msg_complete);
+
+	platform_set_drvdata(pdev, i2c_dev);
+
+	ret = tegra_i2c_init(i2c_dev);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to initialize i2c controller");
+		goto err_free;
+	}
+
+	ret = request_irq(i2c_dev->irq, tegra_i2c_isr, 0, pdev->name, i2c_dev);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to request irq %i\n", i2c_dev->irq);
+		goto err_free;
+	}
+
+	clk_enable(i2c_dev->i2c_clk);
+
+	i2c_set_adapdata(&i2c_dev->adapter, i2c_dev);
+	i2c_dev->adapter.owner = THIS_MODULE;
+	i2c_dev->adapter.class = I2C_CLASS_HWMON;
+	strlcpy(i2c_dev->adapter.name, "Tegra I2C adapter",
+		sizeof(i2c_dev->adapter.name));
+	i2c_dev->adapter.algo = &tegra_i2c_algo;
+	i2c_dev->adapter.dev.parent = &pdev->dev;
+	i2c_dev->adapter.nr = pdev->id;
+
+	ret = i2c_add_numbered_adapter(&i2c_dev->adapter);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to add I2C adapter\n");
+		goto err_free_irq;
+	}
+
+	return 0;
+err_free_irq:
+	free_irq(i2c_dev->irq, i2c_dev);
+err_free:
+	kfree(i2c_dev);
+err_i2c_clk_put:
+	clk_put(i2c_clk);
+err_clk_put:
+	clk_put(clk);
+err_release_region:
+	release_mem_region(iomem->start, resource_size(iomem));
+err_iounmap:
+	iounmap(base);
+	return ret;
+}
+
+static int tegra_i2c_remove(struct platform_device *pdev)
+{
+	struct tegra_i2c_dev *i2c_dev = platform_get_drvdata(pdev);
+	i2c_del_adapter(&i2c_dev->adapter);
+	free_irq(i2c_dev->irq, i2c_dev);
+	clk_put(i2c_dev->i2c_clk);
+	clk_put(i2c_dev->clk);
+	release_mem_region(i2c_dev->iomem->start,
+		resource_size(i2c_dev->iomem));
+	iounmap(i2c_dev->base);
+	kfree(i2c_dev);
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int tegra_i2c_suspend(struct platform_device *pdev, pm_message_t state)
+{
+	struct tegra_i2c_dev *i2c_dev = platform_get_drvdata(pdev);
+
+	i2c_lock_adapter(&i2c_dev->adapter);
+	i2c_dev->is_suspended = true;
+	i2c_unlock_adapter(&i2c_dev->adapter);
+
+	return 0;
+}
+
+static int tegra_i2c_resume(struct platform_device *pdev)
+{
+	struct tegra_i2c_dev *i2c_dev = platform_get_drvdata(pdev);
+	int ret;
+
+	i2c_lock_adapter(&i2c_dev->adapter);
+
+	ret = tegra_i2c_init(i2c_dev);
+
+	if (ret) {
+		i2c_unlock_adapter(&i2c_dev->adapter);
+		return ret;
+	}
+
+	i2c_dev->is_suspended = false;
+
+	i2c_unlock_adapter(&i2c_dev->adapter);
+
+	return 0;
+}
+#endif
+
+static struct platform_driver tegra_i2c_driver = {
+	.probe   = tegra_i2c_probe,
+	.remove  = tegra_i2c_remove,
+#ifdef CONFIG_PM
+	.suspend = tegra_i2c_suspend,
+	.resume  = tegra_i2c_resume,
+#endif
+	.driver  = {
+		.name  = "tegra-i2c",
+		.owner = THIS_MODULE,
+	},
+};
+
+static int __init tegra_i2c_init_driver(void)
+{
+	return platform_driver_register(&tegra_i2c_driver);
+}
+
+static void __exit tegra_i2c_exit_driver(void)
+{
+	platform_driver_unregister(&tegra_i2c_driver);
+}
+
+subsys_initcall(tegra_i2c_init_driver);
+module_exit(tegra_i2c_exit_driver);
+
+MODULE_DESCRIPTION("nVidia Tegra2 I2C Bus Controller driver");
+MODULE_AUTHOR("Colin Cross");
+MODULE_LICENSE("GPL v2");

include/linux/i2c-tegra.h

···
+/*
+ * drivers/i2c/busses/i2c-tegra.c
+ *
+ * Copyright (C) 2010 Google, Inc.
+ * Author: Colin Cross <[e-mail]>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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.
+ *
+ */
+
+#ifndef _LINUX_I2C_TEGRA_H
+#define _LINUX_I2C_TEGRA_H
+
+struct tegra_i2c_platform_data {
+	unsigned long bus_clk_rate;
+};
+
+#endif /* _LINUX_I2C_TEGRA_H */