i2c: brcmstb: Add Broadcom settop SoC i2c controller driver

Adding support for i2c controller driver for Broadcom settop
SoCs.

Signed-off-by: Kamal Dasu <kdasu.kdev@gmail.com>
[wsa: removed superfluous owner in platform_driver]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

3 files changed, 705 insertions, 0 deletions

diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 8a639dce5173..b8c3d6b53861 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -392,6 +392,16 @@ config I2C_BCM_KONA
 
 	  If you do not need KONA I2C interface, say N.
 
+config I2C_BRCMSTB
+	tristate "BRCM Settop I2C controller"
+	depends on ARCH_BRCMSTB || COMPILE_TEST
+	default y
+	help
+	  If you say yes to this option, support will be included for the
+	  I2C interface on the Broadcom Settop SoCs.
+
+	  If you do not need I2C interface, say N.
+
 config I2C_BLACKFIN_TWI
 	tristate "Blackfin TWI I2C support"
 	depends on BLACKFIN
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index 65995423c680..e5f537c80da0 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -106,6 +106,7 @@ obj-$(CONFIG_I2C_VIPERBOARD)	+= i2c-viperboard.o
 # Other I2C/SMBus bus drivers
 obj-$(CONFIG_I2C_ACORN)		+= i2c-acorn.o
 obj-$(CONFIG_I2C_BCM_KONA)	+= i2c-bcm-kona.o
+obj-$(CONFIG_I2C_BRCMSTB)	+= i2c-brcmstb.o
 obj-$(CONFIG_I2C_CROS_EC_TUNNEL)	+= i2c-cros-ec-tunnel.o
 obj-$(CONFIG_I2C_ELEKTOR)	+= i2c-elektor.o
 obj-$(CONFIG_I2C_OPAL)		+= i2c-opal.o
diff --git a/drivers/i2c/busses/i2c-brcmstb.c b/drivers/i2c/busses/i2c-brcmstb.c
new file mode 100644
index 000000000000..8e9637eea512
--- /dev/null
+++ b/drivers/i2c/busses/i2c-brcmstb.c
@@ -0,0 +1,694 @@
+/*
+ * Copyright (C) 2014 Broadcom Corporation
+ *
+ * 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 version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/version.h>
+
+#define N_DATA_REGS					8
+#define N_DATA_BYTES					(N_DATA_REGS * 4)
+
+/* BSC count register field definitions */
+#define BSC_CNT_REG1_MASK				0x0000003f
+#define BSC_CNT_REG1_SHIFT				0
+#define BSC_CNT_REG2_MASK				0x00000fc0
+#define BSC_CNT_REG2_SHIFT				6
+
+/* BSC CTL register field definitions */
+#define BSC_CTL_REG_DTF_MASK				0x00000003
+#define BSC_CTL_REG_SCL_SEL_MASK			0x00000030
+#define BSC_CTL_REG_SCL_SEL_SHIFT			4
+#define BSC_CTL_REG_INT_EN_MASK				0x00000040
+#define BSC_CTL_REG_INT_EN_SHIFT			6
+#define BSC_CTL_REG_DIV_CLK_MASK			0x00000080
+
+/* BSC_IIC_ENABLE r/w enable and interrupt field defintions */
+#define BSC_IIC_EN_RESTART_MASK				0x00000040
+#define BSC_IIC_EN_NOSTART_MASK				0x00000020
+#define BSC_IIC_EN_NOSTOP_MASK				0x00000010
+#define BSC_IIC_EN_NOACK_MASK				0x00000004
+#define BSC_IIC_EN_INTRP_MASK				0x00000002
+#define BSC_IIC_EN_ENABLE_MASK				0x00000001
+
+/* BSC_CTLHI control register field definitions */
+#define BSC_CTLHI_REG_INPUT_SWITCHING_LEVEL_MASK	0x00000080
+#define BSC_CTLHI_REG_DATAREG_SIZE_MASK			0x00000040
+#define BSC_CTLHI_REG_IGNORE_ACK_MASK			0x00000002
+#define BSC_CTLHI_REG_WAIT_DIS_MASK			0x00000001
+
+#define I2C_TIMEOUT					100 /* msecs */
+
+/* Condition mask used for non combined transfer */
+#define COND_RESTART		BSC_IIC_EN_RESTART_MASK
+#define COND_NOSTART		BSC_IIC_EN_NOSTART_MASK
+#define COND_NOSTOP		BSC_IIC_EN_NOSTOP_MASK
+#define COND_START_STOP		(COND_RESTART | COND_NOSTART | COND_NOSTOP)
+
+/* BSC data transfer direction */
+#define DTF_WR_MASK		0x00000000
+#define DTF_RD_MASK		0x00000001
+/* BSC data transfer direction combined format */
+#define DTF_RD_WR_MASK		0x00000002
+#define DTF_WR_RD_MASK		0x00000003
+
+#define INT_ENABLE		true
+#define INT_DISABLE		false
+
+/* BSC block register map structure to cache fields to be written */
+struct bsc_regs {
+	u32	chip_address;           /* slave address */
+	u32	data_in[N_DATA_REGS];   /* tx data buffer*/
+	u32	cnt_reg;		/* rx/tx data length */
+	u32	ctl_reg;		/* control register */
+	u32	iic_enable;		/* xfer enable and status */
+	u32	data_out[N_DATA_REGS];  /* rx data buffer */
+	u32	ctlhi_reg;		/* more control fields */
+	u32	scl_param;		/* reserved */
+};
+
+struct bsc_clk_param {
+	u32 hz;
+	u32 scl_mask;
+	u32 div_mask;
+};
+
+enum bsc_xfer_cmd {
+	CMD_WR,
+	CMD_RD,
+	CMD_WR_NOACK,
+	CMD_RD_NOACK,
+};
+
+static char const *cmd_string[] = {
+	[CMD_WR] = "WR",
+	[CMD_RD] = "RD",
+	[CMD_WR_NOACK] = "WR NOACK",
+	[CMD_RD_NOACK] = "RD NOACK",
+};
+
+enum bus_speeds {
+	SPD_375K,
+	SPD_390K,
+	SPD_187K,
+	SPD_200K,
+	SPD_93K,
+	SPD_97K,
+	SPD_46K,
+	SPD_50K
+};
+
+static const struct bsc_clk_param bsc_clk[] = {
+	[SPD_375K] = {
+		.hz = 375000,
+		.scl_mask = SPD_375K << BSC_CTL_REG_SCL_SEL_SHIFT,
+		.div_mask = 0
+	},
+	[SPD_390K] = {
+		.hz = 390000,
+		.scl_mask = SPD_390K << BSC_CTL_REG_SCL_SEL_SHIFT,
+		.div_mask = 0
+	},
+	[SPD_187K] = {
+		.hz = 187500,
+		.scl_mask = SPD_187K << BSC_CTL_REG_SCL_SEL_SHIFT,
+		.div_mask = 0
+	},
+	[SPD_200K] = {
+		.hz = 200000,
+		.scl_mask = SPD_200K << BSC_CTL_REG_SCL_SEL_SHIFT,
+		.div_mask = 0
+	},
+	[SPD_93K]  = {
+		.hz = 93750,
+		.scl_mask = SPD_375K << BSC_CTL_REG_SCL_SEL_SHIFT,
+		.div_mask = BSC_CTL_REG_DIV_CLK_MASK
+	},
+	[SPD_97K]  = {
+		.hz = 97500,
+		.scl_mask = SPD_390K << BSC_CTL_REG_SCL_SEL_SHIFT,
+		.div_mask = BSC_CTL_REG_DIV_CLK_MASK
+	},
+	[SPD_46K]  = {
+		.hz = 46875,
+		.scl_mask = SPD_187K << BSC_CTL_REG_SCL_SEL_SHIFT,
+		.div_mask = BSC_CTL_REG_DIV_CLK_MASK
+	},
+	[SPD_50K]  = {
+		.hz = 50000,
+		.scl_mask = SPD_200K << BSC_CTL_REG_SCL_SEL_SHIFT,
+		.div_mask = BSC_CTL_REG_DIV_CLK_MASK
+	}
+};
+
+struct brcmstb_i2c_dev {
+	struct device *device;
+	void __iomem *base;
+	void __iomem *irq_base;
+	int irq;
+	struct bsc_regs *bsc_regmap;
+	struct i2c_adapter adapter;
+	struct completion done;
+	bool is_suspended;
+	u32 clk_freq_hz;
+};
+
+/* register accessors for both be and le cpu arch */
+#ifdef CONFIG_CPU_BIG_ENDIAN
+#define __bsc_readl(_reg) ioread32be(_reg)
+#define __bsc_writel(_val, _reg) iowrite32be(_val, _reg)
+#else
+#define __bsc_readl(_reg) ioread32(_reg)
+#define __bsc_writel(_val, _reg) iowrite32(_val, _reg)
+#endif
+
+#define bsc_readl(_dev, _reg)						\
+	__bsc_readl(_dev->base + offsetof(struct bsc_regs, _reg))
+
+#define bsc_writel(_dev, _val, _reg)					\
+	__bsc_writel(_val, _dev->base + offsetof(struct bsc_regs, _reg))
+
+static void brcmstb_i2c_enable_disable_irq(struct brcmstb_i2c_dev *dev,
+					   bool int_en)
+{
+
+	if (int_en)
+		/* Enable BSC  CTL interrupt line */
+		dev->bsc_regmap->ctl_reg |= BSC_CTL_REG_INT_EN_MASK;
+	else
+		/* Disable BSC CTL interrupt line */
+		dev->bsc_regmap->ctl_reg &= ~BSC_CTL_REG_INT_EN_MASK;
+
+	barrier();
+	bsc_writel(dev, dev->bsc_regmap->ctl_reg, ctl_reg);
+}
+
+static irqreturn_t brcmstb_i2c_isr(int irq, void *devid)
+{
+	struct brcmstb_i2c_dev *dev = devid;
+	u32 status_bsc_ctl = bsc_readl(dev, ctl_reg);
+	u32 status_iic_intrp = bsc_readl(dev, iic_enable);
+
+	dev_dbg(dev->device, "isr CTL_REG %x IIC_EN %x\n",
+		status_bsc_ctl, status_iic_intrp);
+
+	if (!(status_bsc_ctl & BSC_CTL_REG_INT_EN_MASK))
+		return IRQ_NONE;
+
+	brcmstb_i2c_enable_disable_irq(dev, INT_DISABLE);
+	complete_all(&dev->done);
+
+	dev_dbg(dev->device, "isr handled");
+	return IRQ_HANDLED;
+}
+
+/* Wait for device to be ready */
+static int brcmstb_i2c_wait_if_busy(struct brcmstb_i2c_dev *dev)
+{
+	unsigned long timeout = jiffies + msecs_to_jiffies(I2C_TIMEOUT);
+
+	while ((bsc_readl(dev, iic_enable) & BSC_IIC_EN_INTRP_MASK)) {
+		if (time_after(jiffies, timeout))
+			return -ETIMEDOUT;
+		cpu_relax();
+	}
+	return 0;
+}
+
+/* i2c xfer completion function, handles both irq and polling mode */
+static int brcmstb_i2c_wait_for_completion(struct brcmstb_i2c_dev *dev)
+{
+	int ret = 0;
+	unsigned long timeout = msecs_to_jiffies(I2C_TIMEOUT);
+
+	if (dev->irq >= 0) {
+		if (!wait_for_completion_timeout(&dev->done, timeout))
+			ret = -ETIMEDOUT;
+	} else {
+		/* we are in polling mode */
+		u32 bsc_intrp;
+		unsigned long time_left = jiffies + timeout;
+
+		do {
+			bsc_intrp = bsc_readl(dev, iic_enable) &
+				BSC_IIC_EN_INTRP_MASK;
+			if (time_after(jiffies, time_left)) {
+				ret = -ETIMEDOUT;
+				break;
+			}
+			cpu_relax();
+		} while (!bsc_intrp);
+	}
+
+	if (dev->irq < 0 || ret == -ETIMEDOUT)
+		brcmstb_i2c_enable_disable_irq(dev, INT_DISABLE);
+
+	return ret;
+}
+
+/* Set xfer START/STOP conditions for subsequent transfer */
+static void brcmstb_set_i2c_start_stop(struct brcmstb_i2c_dev *dev,
+				       u32 cond_flag)
+{
+	u32 regval = dev->bsc_regmap->iic_enable;
+
+	dev->bsc_regmap->iic_enable = (regval & ~COND_START_STOP) | cond_flag;
+}
+
+/* Send I2C request check completion */
+static int brcmstb_send_i2c_cmd(struct brcmstb_i2c_dev *dev,
+				enum bsc_xfer_cmd cmd)
+{
+	int rc = 0;
+	struct bsc_regs *pi2creg = dev->bsc_regmap;
+
+	/* Make sure the hardware is ready */
+	rc = brcmstb_i2c_wait_if_busy(dev);
+	if (rc < 0)
+		return rc;
+
+	/* only if we are in interrupt mode */
+	if (dev->irq >= 0)
+		reinit_completion(&dev->done);
+
+	/* enable BSC CTL interrupt line */
+	brcmstb_i2c_enable_disable_irq(dev, INT_ENABLE);
+
+	/* initiate transfer by setting iic_enable */
+	pi2creg->iic_enable |= BSC_IIC_EN_ENABLE_MASK;
+	bsc_writel(dev, pi2creg->iic_enable, iic_enable);
+
+	/* Wait for transaction to finish or timeout */
+	rc = brcmstb_i2c_wait_for_completion(dev);
+	if (rc) {
+		dev_dbg(dev->device, "intr timeout for cmd %s\n",
+			cmd_string[cmd]);
+		goto cmd_out;
+	}
+
+	if ((CMD_RD || CMD_WR) &&
+	    bsc_readl(dev, iic_enable) & BSC_IIC_EN_NOACK_MASK) {
+		rc = -EREMOTEIO;
+		dev_dbg(dev->device, "controller received NOACK intr for %s\n",
+			cmd_string[cmd]);
+	}
+
+cmd_out:
+	bsc_writel(dev, 0, cnt_reg);
+	bsc_writel(dev, 0, iic_enable);
+
+	return rc;
+}
+
+/* Actual data transfer through the BSC master */
+static int brcmstb_i2c_xfer_bsc_data(struct brcmstb_i2c_dev *dev,
+				     u8 *buf, unsigned int len,
+				     struct i2c_msg *pmsg)
+{
+	int cnt, byte, rc;
+	enum bsc_xfer_cmd cmd;
+	u32 ctl_reg;
+	struct bsc_regs *pi2creg = dev->bsc_regmap;
+	int no_ack = pmsg->flags & I2C_M_IGNORE_NAK;
+
+	/* see if the transaction needs to check NACK conditions */
+	if (no_ack || len <= N_DATA_BYTES) {
+		cmd = (pmsg->flags & I2C_M_RD) ? CMD_RD_NOACK
+			: CMD_WR_NOACK;
+		pi2creg->ctlhi_reg |= BSC_CTLHI_REG_IGNORE_ACK_MASK;
+	} else {
+		cmd = (pmsg->flags & I2C_M_RD) ? CMD_RD : CMD_WR;
+		pi2creg->ctlhi_reg &= ~BSC_CTLHI_REG_IGNORE_ACK_MASK;
+	}
+	bsc_writel(dev, pi2creg->ctlhi_reg, ctlhi_reg);
+
+	/* set data transfer direction */
+	ctl_reg = pi2creg->ctl_reg & ~BSC_CTL_REG_DTF_MASK;
+	if (cmd == CMD_WR || cmd == CMD_WR_NOACK)
+		pi2creg->ctl_reg = ctl_reg | DTF_WR_MASK;
+	else
+		pi2creg->ctl_reg = ctl_reg | DTF_RD_MASK;
+
+	/* set the read/write length */
+	bsc_writel(dev, BSC_CNT_REG1_MASK & (len << BSC_CNT_REG1_SHIFT),
+		   cnt_reg);
+
+	/* Write data into data_in register */
+	if (cmd == CMD_WR || cmd == CMD_WR_NOACK) {
+		for (cnt = 0; cnt < len; cnt += 4) {
+			u32 word = 0;
+
+			for (byte = 0; byte < 4; byte++) {
+				word >>= 8;
+				if ((cnt + byte) < len)
+					word |= buf[cnt + byte] << 24;
+			}
+			bsc_writel(dev, word, data_in[cnt >> 2]);
+		}
+	}
+
+	/* Initiate xfer, the function will return on completion */
+	rc = brcmstb_send_i2c_cmd(dev, cmd);
+
+	if (rc != 0) {
+		dev_dbg(dev->device, "%s failure", cmd_string[cmd]);
+		return rc;
+	}
+
+	if (cmd == CMD_RD || cmd == CMD_RD_NOACK) {
+		for (cnt = 0; cnt < len; cnt += 4) {
+			u32 data = bsc_readl(dev, data_out[cnt >> 2]);
+
+			for (byte = 0; byte < 4 &&
+				     (byte + cnt) < len; byte++) {
+				buf[cnt + byte] = data & 0xff;
+				data >>= 8;
+			}
+		}
+	}
+
+	return 0;
+}
+
+/* Write a single byte of data to the i2c bus */
+static int brcmstb_i2c_write_data_byte(struct brcmstb_i2c_dev *dev,
+				       u8 *buf, unsigned int nak_expected)
+{
+	enum bsc_xfer_cmd cmd = nak_expected ? CMD_WR : CMD_WR_NOACK;
+
+	bsc_writel(dev, 1, cnt_reg);
+	bsc_writel(dev, *buf, data_in);
+
+	return brcmstb_send_i2c_cmd(dev, cmd);
+}
+
+/* Send i2c address */
+static int brcmstb_i2c_do_addr(struct brcmstb_i2c_dev *dev,
+			       struct i2c_msg *msg)
+{
+	unsigned char addr;
+
+	if (msg->flags & I2C_M_TEN) {
+		/* First byte is 11110XX0 where XX is upper 2 bits */
+		addr = 0xF0 | ((msg->addr & 0x300) >> 7);
+		bsc_writel(dev, addr, chip_address);
+
+		/* Second byte is the remaining 8 bits */
+		addr = msg->addr & 0xFF;
+		if (brcmstb_i2c_write_data_byte(dev, &addr, 0) < 0)
+			return -EREMOTEIO;
+
+		if (msg->flags & I2C_M_RD) {
+			/* For read, send restart without stop condition */
+			brcmstb_set_i2c_start_stop(dev, COND_RESTART
+						   | COND_NOSTOP);
+			/* Then re-send the first byte with the read bit set */
+			addr = 0xF0 | ((msg->addr & 0x300) >> 7) | 0x01;
+			if (brcmstb_i2c_write_data_byte(dev, &addr, 0) < 0)
+				return -EREMOTEIO;
+
+		}
+	} else {
+		addr = msg->addr << 1;
+		if (msg->flags & I2C_M_RD)
+			addr |= 1;
+
+		bsc_writel(dev, addr, chip_address);
+	}
+
+	return 0;
+}
+
+/* Master transfer function */
+static int brcmstb_i2c_xfer(struct i2c_adapter *adapter,
+			    struct i2c_msg msgs[], int num)
+{
+	struct brcmstb_i2c_dev *dev = i2c_get_adapdata(adapter);
+	struct i2c_msg *pmsg;
+	int rc = 0;
+	int i;
+	int bytes_to_xfer;
+	u8 *tmp_buf;
+	int len = 0;
+
+	if (dev->is_suspended)
+		return -EBUSY;
+
+	/* Loop through all messages */
+	for (i = 0; i < num; i++) {
+		pmsg = &msgs[i];
+		len = pmsg->len;
+		tmp_buf = pmsg->buf;
+
+		dev_dbg(dev->device,
+			"msg# %d/%d flg %x buf %x len %d\n", i,
+			num - 1, pmsg->flags,
+			pmsg->buf ? pmsg->buf[0] : '0', pmsg->len);
+
+		if (i < (num - 1) && (msgs[i + 1].flags & I2C_M_NOSTART))
+			brcmstb_set_i2c_start_stop(dev, ~(COND_START_STOP));
+		else
+			brcmstb_set_i2c_start_stop(dev,
+						   COND_RESTART | COND_NOSTOP);
+
+		/* Send slave address */
+		if (!(pmsg->flags & I2C_M_NOSTART)) {
+			rc = brcmstb_i2c_do_addr(dev, pmsg);
+			if (rc < 0) {
+				dev_dbg(dev->device,
+					"NACK for addr %2.2x msg#%d rc = %d\n",
+					pmsg->addr, i, rc);
+				goto out;
+			}
+		}
+
+		/* Perform data transfer */
+		while (len) {
+			bytes_to_xfer = min(len, N_DATA_BYTES);
+
+			if (len <= N_DATA_BYTES && i == (num - 1))
+				brcmstb_set_i2c_start_stop(dev,
+							   ~(COND_START_STOP));
+
+			rc = brcmstb_i2c_xfer_bsc_data(dev, tmp_buf,
+						       bytes_to_xfer, pmsg);
+			if (rc < 0)
+				goto out;
+
+			len -=  bytes_to_xfer;
+			tmp_buf += bytes_to_xfer;
+		}
+	}
+
+	rc = num;
+out:
+	return rc;
+
+}
+
+static u32 brcmstb_i2c_functionality(struct i2c_adapter *adap)
+{
+	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR
+		| I2C_FUNC_NOSTART | I2C_FUNC_PROTOCOL_MANGLING;
+}
+
+static const struct i2c_algorithm brcmstb_i2c_algo = {
+	.master_xfer = brcmstb_i2c_xfer,
+	.functionality = brcmstb_i2c_functionality,
+};
+
+static void brcmstb_i2c_set_bus_speed(struct brcmstb_i2c_dev *dev)
+{
+	int i = 0, num_speeds = ARRAY_SIZE(bsc_clk);
+	u32 clk_freq_hz = dev->clk_freq_hz;
+
+	for (i = 0; i < num_speeds; i++) {
+		if (bsc_clk[i].hz == clk_freq_hz) {
+			dev->bsc_regmap->ctl_reg &= ~(BSC_CTL_REG_SCL_SEL_MASK
+						| BSC_CTL_REG_DIV_CLK_MASK);
+			dev->bsc_regmap->ctl_reg |= (bsc_clk[i].scl_mask |
+						     bsc_clk[i].div_mask);
+			bsc_writel(dev, dev->bsc_regmap->ctl_reg, ctl_reg);
+			break;
+		}
+	}
+
+	/* in case we did not get find a valid speed */
+	if (i == num_speeds) {
+		i = (bsc_readl(dev, ctl_reg) & BSC_CTL_REG_SCL_SEL_MASK) >>
+			BSC_CTL_REG_SCL_SEL_SHIFT;
+		dev_warn(dev->device, "leaving current clock-frequency @ %dHz\n",
+			bsc_clk[i].hz);
+	}
+}
+
+static void brcmstb_i2c_set_bsc_reg_defaults(struct brcmstb_i2c_dev *dev)
+{
+	/* 4 byte data register */
+	dev->bsc_regmap->ctlhi_reg = BSC_CTLHI_REG_DATAREG_SIZE_MASK;
+	bsc_writel(dev, dev->bsc_regmap->ctlhi_reg, ctlhi_reg);
+	/* set bus speed */
+	brcmstb_i2c_set_bus_speed(dev);
+}
+
+static int brcmstb_i2c_probe(struct platform_device *pdev)
+{
+	int rc = 0;
+	struct brcmstb_i2c_dev *dev;
+	struct i2c_adapter *adap;
+	struct resource *iomem;
+	const char *int_name;
+
+	/* Allocate memory for private data structure */
+	dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
+	if (!dev)
+		return -ENOMEM;
+
+	dev->bsc_regmap = devm_kzalloc(&pdev->dev, sizeof(struct bsc_regs *),
+				       GFP_KERNEL);
+	if (!dev->bsc_regmap)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, dev);
+	dev->device = &pdev->dev;
+	init_completion(&dev->done);
+
+	/* Map hardware registers */
+	iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	dev->base = devm_ioremap_resource(dev->device, iomem);
+	if (IS_ERR(dev->base)) {
+		rc = -ENOMEM;
+		goto probe_errorout;
+	}
+
+	rc = of_property_read_string(dev->device->of_node, "interrupt-names",
+				     &int_name);
+	if (rc < 0)
+		int_name = NULL;
+
+	/* Get the interrupt number */
+	dev->irq = platform_get_irq(pdev, 0);
+
+	/* disable the bsc interrupt line */
+	brcmstb_i2c_enable_disable_irq(dev, INT_DISABLE);
+
+	/* register the ISR handler */
+	rc = devm_request_irq(&pdev->dev, dev->irq, brcmstb_i2c_isr,
+			      IRQF_SHARED,
+			      int_name ? int_name : pdev->name,
+			      dev);
+
+	if (rc) {
+		dev_dbg(dev->device, "falling back to polling mode");
+		dev->irq = -1;
+	}
+
+	if (of_property_read_u32(dev->device->of_node,
+				 "clock-frequency", &dev->clk_freq_hz)) {
+		dev_warn(dev->device, "setting clock-frequency@%dHz\n",
+			 bsc_clk[0].hz);
+		dev->clk_freq_hz = bsc_clk[0].hz;
+	}
+
+	brcmstb_i2c_set_bsc_reg_defaults(dev);
+
+	/* Add the i2c adapter */
+	adap = &dev->adapter;
+	i2c_set_adapdata(adap, dev);
+	adap->owner = THIS_MODULE;
+	strlcpy(adap->name, "Broadcom STB : ", sizeof(adap->name));
+	if (int_name)
+		strlcat(adap->name, int_name, sizeof(adap->name));
+	adap->algo = &brcmstb_i2c_algo;
+	adap->dev.parent = &pdev->dev;
+	adap->dev.of_node = pdev->dev.of_node;
+	rc = i2c_add_adapter(adap);
+	if (rc) {
+		dev_err(dev->device, "failed to add adapter\n");
+		goto probe_errorout;
+	}
+
+	dev_info(dev->device, "%s@%dhz registered in %s mode\n",
+		 int_name ? int_name : " ", dev->clk_freq_hz,
+		 (dev->irq >= 0) ? "interrupt" : "polling");
+
+	return 0;
+
+probe_errorout:
+	return rc;
+}
+
+static int brcmstb_i2c_remove(struct platform_device *pdev)
+{
+	struct brcmstb_i2c_dev *dev = platform_get_drvdata(pdev);
+
+	i2c_del_adapter(&dev->adapter);
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int brcmstb_i2c_suspend(struct device *dev)
+{
+	struct brcmstb_i2c_dev *i2c_dev = dev_get_drvdata(dev);
+
+	i2c_lock_adapter(&i2c_dev->adapter);
+	i2c_dev->is_suspended = true;
+	i2c_unlock_adapter(&i2c_dev->adapter);
+
+	return 0;
+}
+
+static int brcmstb_i2c_resume(struct device *dev)
+{
+	struct brcmstb_i2c_dev *i2c_dev = dev_get_drvdata(dev);
+
+	i2c_lock_adapter(&i2c_dev->adapter);
+	brcmstb_i2c_set_bsc_reg_defaults(i2c_dev);
+	i2c_dev->is_suspended = false;
+	i2c_unlock_adapter(&i2c_dev->adapter);
+
+	return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(brcmstb_i2c_pm, brcmstb_i2c_suspend,
+			 brcmstb_i2c_resume);
+
+static const struct of_device_id brcmstb_i2c_of_match[] = {
+	{.compatible = "brcm,brcmstb-i2c"},
+	{},
+};
+MODULE_DEVICE_TABLE(of, brcmstb_i2c_of_match);
+
+static struct platform_driver brcmstb_i2c_driver = {
+	.driver = {
+		   .name = "brcmstb-i2c",
+		   .of_match_table = brcmstb_i2c_of_match,
+		   .pm = &brcmstb_i2c_pm,
+		   },
+	.probe = brcmstb_i2c_probe,
+	.remove = brcmstb_i2c_remove,
+};
+module_platform_driver(brcmstb_i2c_driver);
+
+MODULE_AUTHOR("Kamal Dasu <kdasu@broadcom.com>");
+MODULE_DESCRIPTION("Broadcom Settop I2C Driver");
+MODULE_LICENSE("GPL v2");