1 files changed, 338 insertions, 207 deletions

diff --git a/drivers/i2c/busses/i2c-bcm-iproc.c b/drivers/i2c/busses/i2c-bcm-iproc.c
index 8a3c98866fb7..e418a4f23f15 100644
--- a/drivers/i2c/busses/i2c-bcm-iproc.c
+++ b/drivers/i2c/busses/i2c-bcm-iproc.c
@@ -1,15 +1,5 @@
-/*
- * 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.
- */
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright (C) 2014 Broadcom Corporation
 
 #include <linux/delay.h>
 #include <linux/i2c.h>
@@ -17,7 +7,7 @@
 #include <linux/io.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
-#include <linux/of_device.h>
+#include <linux/of.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 
@@ -93,6 +83,7 @@
 #define S_CMD_STATUS_MASK            0x07
 #define S_CMD_STATUS_SUCCESS         0x0
 #define S_CMD_STATUS_TIMEOUT         0x5
+#define S_CMD_STATUS_MASTER_ABORT    0x7
 
 #define IE_OFFSET                    0x38
 #define IE_M_RX_FIFO_FULL_SHIFT      31
@@ -159,6 +150,11 @@
 
 #define IE_S_ALL_INTERRUPT_SHIFT     21
 #define IE_S_ALL_INTERRUPT_MASK      0x3f
+/*
+ * It takes ~18us to reading 10bytes of data, hence to keep tasklet
+ * running for less time, max slave read per tasklet is set to 10 bytes.
+ */
+#define MAX_SLAVE_RX_PER_INT         10
 
 enum i2c_slave_read_status {
 	I2C_SLAVE_RX_FIFO_EMPTY = 0,
@@ -205,8 +201,18 @@ struct bcm_iproc_i2c_dev {
 	/* bytes that have been read */
 	unsigned int rx_bytes;
 	unsigned int thld_bytes;
+
+	bool slave_rx_only;
+	bool rx_start_rcvd;
+	bool slave_read_complete;
+	u32 tx_underrun;
+	u32 slave_int_mask;
+	struct tasklet_struct slave_rx_tasklet;
 };
 
+/* tasklet to process slave rx data */
+static void slave_rx_tasklet_fn(unsigned long);
+
 /*
  * Can be expanded in the future if more interrupt status bits are utilized
  */
@@ -215,24 +221,21 @@ struct bcm_iproc_i2c_dev {
 
 #define ISR_MASK_SLAVE (BIT(IS_S_START_BUSY_SHIFT)\
 		| BIT(IS_S_RX_EVENT_SHIFT) | BIT(IS_S_RD_EVENT_SHIFT)\
-		| BIT(IS_S_TX_UNDERRUN_SHIFT))
-
-static int bcm_iproc_i2c_reg_slave(struct i2c_client *slave);
-static int bcm_iproc_i2c_unreg_slave(struct i2c_client *slave);
-static void bcm_iproc_i2c_enable_disable(struct bcm_iproc_i2c_dev *iproc_i2c,
-					 bool enable);
+		| BIT(IS_S_TX_UNDERRUN_SHIFT) | BIT(IS_S_RX_FIFO_FULL_SHIFT)\
+		| BIT(IS_S_RX_THLD_SHIFT))
 
 static inline u32 iproc_i2c_rd_reg(struct bcm_iproc_i2c_dev *iproc_i2c,
 				   u32 offset)
 {
 	u32 val;
+	unsigned long flags;
 
 	if (iproc_i2c->idm_base) {
-		spin_lock(&iproc_i2c->idm_lock);
+		spin_lock_irqsave(&iproc_i2c->idm_lock, flags);
 		writel(iproc_i2c->ape_addr_mask,
 		       iproc_i2c->idm_base + IDM_CTRL_DIRECT_OFFSET);
 		val = readl(iproc_i2c->base + offset);
-		spin_unlock(&iproc_i2c->idm_lock);
+		spin_unlock_irqrestore(&iproc_i2c->idm_lock, flags);
 	} else {
 		val = readl(iproc_i2c->base + offset);
 	}
@@ -243,30 +246,33 @@ static inline u32 iproc_i2c_rd_reg(struct bcm_iproc_i2c_dev *iproc_i2c,
 static inline void iproc_i2c_wr_reg(struct bcm_iproc_i2c_dev *iproc_i2c,
 				    u32 offset, u32 val)
 {
+	unsigned long flags;
+
 	if (iproc_i2c->idm_base) {
-		spin_lock(&iproc_i2c->idm_lock);
+		spin_lock_irqsave(&iproc_i2c->idm_lock, flags);
 		writel(iproc_i2c->ape_addr_mask,
 		       iproc_i2c->idm_base + IDM_CTRL_DIRECT_OFFSET);
 		writel(val, iproc_i2c->base + offset);
-		spin_unlock(&iproc_i2c->idm_lock);
+		spin_unlock_irqrestore(&iproc_i2c->idm_lock, flags);
 	} else {
 		writel(val, iproc_i2c->base + offset);
 	}
 }
 
-static void bcm_iproc_i2c_slave_init(
-	struct bcm_iproc_i2c_dev *iproc_i2c, bool need_reset)
+static void bcm_iproc_i2c_slave_init(struct bcm_iproc_i2c_dev *iproc_i2c,
+				     bool need_reset)
 {
 	u32 val;
 
+	iproc_i2c->tx_underrun = 0;
 	if (need_reset) {
 		/* put controller in reset */
 		val = iproc_i2c_rd_reg(iproc_i2c, CFG_OFFSET);
 		val |= BIT(CFG_RESET_SHIFT);
 		iproc_i2c_wr_reg(iproc_i2c, CFG_OFFSET, val);
 
-		/* wait 100 usec per spec */
-		udelay(100);
+		/* wait approximately 100 usec as per spec */
+		usleep_range(100, 200);
 
 		/* bring controller out of reset */
 		val &= ~(BIT(CFG_RESET_SHIFT));
@@ -295,109 +301,255 @@ static void bcm_iproc_i2c_slave_init(
 
 	/* Enable interrupt register to indicate a valid byte in receive fifo */
 	val = BIT(IE_S_RX_EVENT_SHIFT);
+	/* Enable interrupt register to indicate Slave Rx FIFO Full */
+	val |= BIT(IE_S_RX_FIFO_FULL_SHIFT);
+	/* Enable interrupt register to indicate a Master read transaction */
+	val |= BIT(IE_S_RD_EVENT_SHIFT);
 	/* Enable interrupt register for the Slave BUSY command */
 	val |= BIT(IE_S_START_BUSY_SHIFT);
+	iproc_i2c->slave_int_mask = val;
 	iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, val);
 }
 
-static void bcm_iproc_i2c_check_slave_status(
-	struct bcm_iproc_i2c_dev *iproc_i2c)
+static void bcm_iproc_i2c_enable_disable(struct bcm_iproc_i2c_dev *iproc_i2c,
+					 bool enable)
 {
 	u32 val;
 
-	val = iproc_i2c_rd_reg(iproc_i2c, S_CMD_OFFSET);
-	/* status is valid only when START_BUSY is cleared after it was set */
-	if (val & BIT(S_CMD_START_BUSY_SHIFT))
-		return;
+	val = iproc_i2c_rd_reg(iproc_i2c, CFG_OFFSET);
+	if (enable)
+		val |= BIT(CFG_EN_SHIFT);
+	else
+		val &= ~BIT(CFG_EN_SHIFT);
+	iproc_i2c_wr_reg(iproc_i2c, CFG_OFFSET, val);
+}
+
+static bool bcm_iproc_i2c_check_slave_status
+	(struct bcm_iproc_i2c_dev *iproc_i2c, u32 status)
+{
+	u32 val;
+	bool recover = false;
+
+	/* check slave transmit status only if slave is transmitting */
+	if (!iproc_i2c->slave_rx_only) {
+		val = iproc_i2c_rd_reg(iproc_i2c, S_CMD_OFFSET);
+		/* status is valid only when START_BUSY is cleared */
+		if (!(val & BIT(S_CMD_START_BUSY_SHIFT))) {
+			val = (val >> S_CMD_STATUS_SHIFT) & S_CMD_STATUS_MASK;
+			if (val == S_CMD_STATUS_TIMEOUT ||
+			    val == S_CMD_STATUS_MASTER_ABORT) {
+				dev_warn(iproc_i2c->device,
+					 (val == S_CMD_STATUS_TIMEOUT) ?
+					 "slave random stretch time timeout\n" :
+					 "Master aborted read transaction\n");
+				recover = true;
+			}
+		}
+	}
 
-	val = (val >> S_CMD_STATUS_SHIFT) & S_CMD_STATUS_MASK;
-	if (val == S_CMD_STATUS_TIMEOUT) {
-		dev_err(iproc_i2c->device, "slave random stretch time timeout\n");
+	/* RX_EVENT is not valid when START_BUSY is set */
+	if ((status & BIT(IS_S_RX_EVENT_SHIFT)) &&
+	    (status & BIT(IS_S_START_BUSY_SHIFT))) {
+		dev_warn(iproc_i2c->device, "Slave aborted read transaction\n");
+		recover = true;
+	}
 
+	if (recover) {
 		/* re-initialize i2c for recovery */
 		bcm_iproc_i2c_enable_disable(iproc_i2c, false);
 		bcm_iproc_i2c_slave_init(iproc_i2c, true);
 		bcm_iproc_i2c_enable_disable(iproc_i2c, true);
 	}
+
+	return recover;
 }
 
-static bool bcm_iproc_i2c_slave_isr(struct bcm_iproc_i2c_dev *iproc_i2c,
-				    u32 status)
+static void bcm_iproc_i2c_slave_read(struct bcm_iproc_i2c_dev *iproc_i2c)
 {
+	u8 rx_data, rx_status;
+	u32 rx_bytes = 0;
 	u32 val;
-	u8 value, rx_status;
 
-	/* Slave RX byte receive */
-	if (status & BIT(IS_S_RX_EVENT_SHIFT)) {
+	while (rx_bytes < MAX_SLAVE_RX_PER_INT) {
 		val = iproc_i2c_rd_reg(iproc_i2c, S_RX_OFFSET);
 		rx_status = (val >> S_RX_STATUS_SHIFT) & S_RX_STATUS_MASK;
-		if (rx_status == I2C_SLAVE_RX_START) {
-			/* Start of SMBUS for Master write */
-			i2c_slave_event(iproc_i2c->slave,
-					I2C_SLAVE_WRITE_REQUESTED, &value);
+		rx_data = ((val >> S_RX_DATA_SHIFT) & S_RX_DATA_MASK);
 
-			val = iproc_i2c_rd_reg(iproc_i2c, S_RX_OFFSET);
-			value = (u8)((val >> S_RX_DATA_SHIFT) & S_RX_DATA_MASK);
+		if (rx_status == I2C_SLAVE_RX_START) {
+			/* Start of SMBUS Master write */
 			i2c_slave_event(iproc_i2c->slave,
-					I2C_SLAVE_WRITE_RECEIVED, &value);
-		} else if (status & BIT(IS_S_RD_EVENT_SHIFT)) {
-			/* Start of SMBUS for Master Read */
+					I2C_SLAVE_WRITE_REQUESTED, &rx_data);
+			iproc_i2c->rx_start_rcvd = true;
+			iproc_i2c->slave_read_complete = false;
+		} else if (rx_status == I2C_SLAVE_RX_DATA &&
+			   iproc_i2c->rx_start_rcvd) {
+			/* Middle of SMBUS Master write */
 			i2c_slave_event(iproc_i2c->slave,
-					I2C_SLAVE_READ_REQUESTED, &value);
-			iproc_i2c_wr_reg(iproc_i2c, S_TX_OFFSET, value);
+					I2C_SLAVE_WRITE_RECEIVED, &rx_data);
+		} else if (rx_status == I2C_SLAVE_RX_END &&
+			   iproc_i2c->rx_start_rcvd) {
+			/* End of SMBUS Master write */
+			if (iproc_i2c->slave_rx_only)
+				i2c_slave_event(iproc_i2c->slave,
+						I2C_SLAVE_WRITE_RECEIVED,
+						&rx_data);
+
+			i2c_slave_event(iproc_i2c->slave, I2C_SLAVE_STOP,
+					&rx_data);
+		} else if (rx_status == I2C_SLAVE_RX_FIFO_EMPTY) {
+			iproc_i2c->rx_start_rcvd = false;
+			iproc_i2c->slave_read_complete = true;
+			break;
+		}
 
-			val = BIT(S_CMD_START_BUSY_SHIFT);
-			iproc_i2c_wr_reg(iproc_i2c, S_CMD_OFFSET, val);
+		rx_bytes++;
+	}
+}
 
-			/*
-			 * Enable interrupt for TX FIFO becomes empty and
-			 * less than PKT_LENGTH bytes were output on the SMBUS
-			 */
-			val = iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET);
-			val |= BIT(IE_S_TX_UNDERRUN_SHIFT);
-			iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, val);
-		} else {
-			/* Master write other than start */
-			value = (u8)((val >> S_RX_DATA_SHIFT) & S_RX_DATA_MASK);
+static void slave_rx_tasklet_fn(unsigned long data)
+{
+	struct bcm_iproc_i2c_dev *iproc_i2c = (struct bcm_iproc_i2c_dev *)data;
+	u32 int_clr;
+
+	bcm_iproc_i2c_slave_read(iproc_i2c);
+
+	/* clear pending IS_S_RX_EVENT_SHIFT interrupt */
+	int_clr = BIT(IS_S_RX_EVENT_SHIFT);
+
+	if (!iproc_i2c->slave_rx_only && iproc_i2c->slave_read_complete) {
+		/*
+		 * In case of single byte master-read request,
+		 * IS_S_TX_UNDERRUN_SHIFT event is generated before
+		 * IS_S_START_BUSY_SHIFT event. Hence start slave data send
+		 * from first IS_S_TX_UNDERRUN_SHIFT event.
+		 *
+		 * This means don't send any data from slave when
+		 * IS_S_RD_EVENT_SHIFT event is generated else it will increment
+		 * eeprom or other backend slave driver read pointer twice.
+		 */
+		iproc_i2c->tx_underrun = 0;
+		iproc_i2c->slave_int_mask |= BIT(IE_S_TX_UNDERRUN_SHIFT);
+
+		/* clear IS_S_RD_EVENT_SHIFT interrupt */
+		int_clr |= BIT(IS_S_RD_EVENT_SHIFT);
+	}
+
+	/* clear slave interrupt */
+	iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, int_clr);
+	/* enable slave interrupts */
+	iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, iproc_i2c->slave_int_mask);
+}
+
+static bool bcm_iproc_i2c_slave_isr(struct bcm_iproc_i2c_dev *iproc_i2c,
+				    u32 status)
+{
+	u32 val;
+	u8 value;
+
+	if (status & BIT(IS_S_TX_UNDERRUN_SHIFT)) {
+		iproc_i2c->tx_underrun++;
+		if (iproc_i2c->tx_underrun == 1)
+			/* Start of SMBUS for Master Read */
 			i2c_slave_event(iproc_i2c->slave,
-					I2C_SLAVE_WRITE_RECEIVED, &value);
-			if (rx_status == I2C_SLAVE_RX_END)
-				i2c_slave_event(iproc_i2c->slave,
-						I2C_SLAVE_STOP, &value);
-		}
-	} else if (status & BIT(IS_S_TX_UNDERRUN_SHIFT)) {
-		/* Master read other than start */
-		i2c_slave_event(iproc_i2c->slave,
-				I2C_SLAVE_READ_PROCESSED, &value);
+					I2C_SLAVE_READ_REQUESTED,
+					&value);
+		else
+			/* Master read other than start */
+			i2c_slave_event(iproc_i2c->slave,
+					I2C_SLAVE_READ_PROCESSED,
+					&value);
 
 		iproc_i2c_wr_reg(iproc_i2c, S_TX_OFFSET, value);
+		/* start transfer */
 		val = BIT(S_CMD_START_BUSY_SHIFT);
 		iproc_i2c_wr_reg(iproc_i2c, S_CMD_OFFSET, val);
+
+		/* clear interrupt */
+		iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET,
+				 BIT(IS_S_TX_UNDERRUN_SHIFT));
 	}
 
-	/* Stop */
+	/* Stop received from master in case of master read transaction */
 	if (status & BIT(IS_S_START_BUSY_SHIFT)) {
-		i2c_slave_event(iproc_i2c->slave, I2C_SLAVE_STOP, &value);
 		/*
-		 * Enable interrupt for TX FIFO becomes empty and
+		 * Disable interrupt for TX FIFO becomes empty and
 		 * less than PKT_LENGTH bytes were output on the SMBUS
 		 */
+		iproc_i2c->slave_int_mask &= ~BIT(IE_S_TX_UNDERRUN_SHIFT);
 		val = iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET);
 		val &= ~BIT(IE_S_TX_UNDERRUN_SHIFT);
 		iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, val);
+
+		/* End of SMBUS for Master Read */
+		val = BIT(S_TX_WR_STATUS_SHIFT);
+		iproc_i2c_wr_reg(iproc_i2c, S_TX_OFFSET, val);
+
+		val = BIT(S_CMD_START_BUSY_SHIFT);
+		iproc_i2c_wr_reg(iproc_i2c, S_CMD_OFFSET, val);
+
+		/* flush TX FIFOs */
+		val = iproc_i2c_rd_reg(iproc_i2c, S_FIFO_CTRL_OFFSET);
+		val |= (BIT(S_FIFO_TX_FLUSH_SHIFT));
+		iproc_i2c_wr_reg(iproc_i2c, S_FIFO_CTRL_OFFSET, val);
+
+		i2c_slave_event(iproc_i2c->slave, I2C_SLAVE_STOP, &value);
+
+		/* clear interrupt */
+		iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET,
+				 BIT(IS_S_START_BUSY_SHIFT));
 	}
 
-	/* clear interrupt status */
-	iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, status);
+	/* if the controller has been reset, immediately return from the ISR */
+	if (bcm_iproc_i2c_check_slave_status(iproc_i2c, status))
+		return true;
+
+	/*
+	 * Slave events in case of master-write, master-write-read and,
+	 * master-read
+	 *
+	 * Master-write     : only IS_S_RX_EVENT_SHIFT event
+	 * Master-write-read: both IS_S_RX_EVENT_SHIFT and IS_S_RD_EVENT_SHIFT
+	 *                    events
+	 * Master-read      : both IS_S_RX_EVENT_SHIFT and IS_S_RD_EVENT_SHIFT
+	 *                    events or only IS_S_RD_EVENT_SHIFT
+	 *
+	 * iproc has a slave rx fifo size of 64 bytes. Rx fifo full interrupt
+	 * (IS_S_RX_FIFO_FULL_SHIFT) will be generated when RX fifo becomes
+	 * full. This can happen if Master issues write requests of more than
+	 * 64 bytes.
+	 */
+	if (status & BIT(IS_S_RX_EVENT_SHIFT) ||
+	    status & BIT(IS_S_RD_EVENT_SHIFT) ||
+	    status & BIT(IS_S_RX_FIFO_FULL_SHIFT)) {
+		/* disable slave interrupts */
+		val = iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET);
+		val &= ~iproc_i2c->slave_int_mask;
+		iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, val);
+
+		if (status & BIT(IS_S_RD_EVENT_SHIFT))
+			/* Master-write-read request */
+			iproc_i2c->slave_rx_only = false;
+		else
+			/* Master-write request only */
+			iproc_i2c->slave_rx_only = true;
+
+		/* schedule tasklet to read data later */
+		tasklet_schedule(&iproc_i2c->slave_rx_tasklet);
+
+		/* clear IS_S_RX_FIFO_FULL_SHIFT interrupt */
+		if (status & BIT(IS_S_RX_FIFO_FULL_SHIFT)) {
+			val = BIT(IS_S_RX_FIFO_FULL_SHIFT);
+			iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, val);
+		}
+	}
 
-	bcm_iproc_i2c_check_slave_status(iproc_i2c);
 	return true;
 }
 
 static void bcm_iproc_i2c_read_valid_bytes(struct bcm_iproc_i2c_dev *iproc_i2c)
 {
 	struct i2c_msg *msg = iproc_i2c->msg;
-	uint32_t val;
+	u32 val;
 
 	/* Read valid data from RX FIFO */
 	while (iproc_i2c->rx_bytes < msg->len) {
@@ -505,12 +657,17 @@ static void bcm_iproc_i2c_process_m_event(struct bcm_iproc_i2c_dev *iproc_i2c,
 static irqreturn_t bcm_iproc_i2c_isr(int irq, void *data)
 {
 	struct bcm_iproc_i2c_dev *iproc_i2c = data;
-	u32 status = iproc_i2c_rd_reg(iproc_i2c, IS_OFFSET);
+	u32 slave_status;
+	u32 status;
 	bool ret;
-	u32 sl_status = status & ISR_MASK_SLAVE;
 
-	if (sl_status) {
-		ret = bcm_iproc_i2c_slave_isr(iproc_i2c, sl_status);
+	status = iproc_i2c_rd_reg(iproc_i2c, IS_OFFSET);
+	/* process only slave interrupt which are enabled */
+	slave_status = status & iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET) &
+		       ISR_MASK_SLAVE;
+
+	if (slave_status) {
+		ret = bcm_iproc_i2c_slave_isr(iproc_i2c, slave_status);
 		if (ret)
 			return IRQ_HANDLED;
 		else
@@ -528,7 +685,7 @@ static irqreturn_t bcm_iproc_i2c_isr(int irq, void *data)
 	return IRQ_HANDLED;
 }
 
-static int bcm_iproc_i2c_init(struct bcm_iproc_i2c_dev *iproc_i2c)
+static void bcm_iproc_i2c_init(struct bcm_iproc_i2c_dev *iproc_i2c)
 {
 	u32 val;
 
@@ -538,8 +695,8 @@ static int bcm_iproc_i2c_init(struct bcm_iproc_i2c_dev *iproc_i2c)
 	val &= ~(BIT(CFG_EN_SHIFT));
 	iproc_i2c_wr_reg(iproc_i2c, CFG_OFFSET, val);
 
-	/* wait 100 usec per spec */
-	udelay(100);
+	/* wait approximately 100 usec as per spec */
+	usleep_range(100, 200);
 
 	/* bring controller out of reset */
 	val &= ~(BIT(CFG_RESET_SHIFT));
@@ -556,21 +713,6 @@ static int bcm_iproc_i2c_init(struct bcm_iproc_i2c_dev *iproc_i2c)
 
 	/* clear all pending interrupts */
 	iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, 0xffffffff);
-
-	return 0;
-}
-
-static void bcm_iproc_i2c_enable_disable(struct bcm_iproc_i2c_dev *iproc_i2c,
-					 bool enable)
-{
-	u32 val;
-
-	val = iproc_i2c_rd_reg(iproc_i2c, CFG_OFFSET);
-	if (enable)
-		val |= BIT(CFG_EN_SHIFT);
-	else
-		val &= ~BIT(CFG_EN_SHIFT);
-	iproc_i2c_wr_reg(iproc_i2c, CFG_OFFSET, val);
 }
 
 static int bcm_iproc_i2c_check_status(struct bcm_iproc_i2c_dev *iproc_i2c,
@@ -586,31 +728,31 @@ static int bcm_iproc_i2c_check_status(struct bcm_iproc_i2c_dev *iproc_i2c,
 		return 0;
 
 	case M_CMD_STATUS_LOST_ARB:
-		dev_dbg(iproc_i2c->device, "lost bus arbitration\n");
+		dev_err(iproc_i2c->device, "lost bus arbitration\n");
 		return -EAGAIN;
 
 	case M_CMD_STATUS_NACK_ADDR:
-		dev_dbg(iproc_i2c->device, "NAK addr:0x%02x\n", msg->addr);
+		dev_err(iproc_i2c->device, "NAK addr:0x%02x\n", msg->addr);
 		return -ENXIO;
 
 	case M_CMD_STATUS_NACK_DATA:
-		dev_dbg(iproc_i2c->device, "NAK data\n");
+		dev_err(iproc_i2c->device, "NAK data\n");
 		return -ENXIO;
 
 	case M_CMD_STATUS_TIMEOUT:
-		dev_dbg(iproc_i2c->device, "bus timeout\n");
+		dev_err(iproc_i2c->device, "bus timeout\n");
 		return -ETIMEDOUT;
 
 	case M_CMD_STATUS_FIFO_UNDERRUN:
-		dev_dbg(iproc_i2c->device, "FIFO under-run\n");
+		dev_err(iproc_i2c->device, "FIFO under-run\n");
 		return -ENXIO;
 
 	case M_CMD_STATUS_RX_FIFO_FULL:
-		dev_dbg(iproc_i2c->device, "RX FIFO full\n");
+		dev_err(iproc_i2c->device, "RX FIFO full\n");
 		return -ETIMEDOUT;
 
 	default:
-		dev_dbg(iproc_i2c->device, "unknown error code=%d\n", val);
+		dev_err(iproc_i2c->device, "unknown error code=%d\n", val);
 
 		/* re-initialize i2c for recovery */
 		bcm_iproc_i2c_enable_disable(iproc_i2c, false);
@@ -661,8 +803,6 @@ static int bcm_iproc_i2c_xfer_wait(struct bcm_iproc_i2c_dev *iproc_i2c,
 	}
 
 	if (!time_left && !iproc_i2c->xfer_is_done) {
-		dev_err(iproc_i2c->device, "transaction timed out\n");
-
 		/* flush both TX/RX FIFOs */
 		val = BIT(M_FIFO_RX_FLUSH_SHIFT) | BIT(M_FIFO_TX_FLUSH_SHIFT);
 		iproc_i2c_wr_reg(iproc_i2c, M_FIFO_CTRL_OFFSET, val);
@@ -687,7 +827,7 @@ static int bcm_iproc_i2c_xfer_wait(struct bcm_iproc_i2c_dev *iproc_i2c,
  * The i2c quirks are set to enforce this rule.
  */
 static int bcm_iproc_i2c_xfer_internal(struct bcm_iproc_i2c_dev *iproc_i2c,
-					struct i2c_msg *msgs, bool process_call)
+				       struct i2c_msg *msgs, bool process_call)
 {
 	int i;
 	u8 addr;
@@ -696,8 +836,8 @@ static int bcm_iproc_i2c_xfer_internal(struct bcm_iproc_i2c_dev *iproc_i2c,
 	struct i2c_msg *msg = &msgs[0];
 
 	/* check if bus is busy */
-	if (!!(iproc_i2c_rd_reg(iproc_i2c,
-				M_CMD_OFFSET) & BIT(M_CMD_START_BUSY_SHIFT))) {
+	if (iproc_i2c_rd_reg(iproc_i2c,
+			     M_CMD_OFFSET) & BIT(M_CMD_START_BUSY_SHIFT)) {
 		dev_warn(iproc_i2c->device, "bus is busy\n");
 		return -EBUSY;
 	}
@@ -720,7 +860,7 @@ static int bcm_iproc_i2c_xfer_internal(struct bcm_iproc_i2c_dev *iproc_i2c,
 
 			/* mark the last byte */
 			if (!process_call && (i == msg->len - 1))
-				val |= 1 << M_TX_WR_STATUS_SHIFT;
+				val |= BIT(M_TX_WR_STATUS_SHIFT);
 
 			iproc_i2c_wr_reg(iproc_i2c, M_TX_OFFSET, val);
 		}
@@ -738,7 +878,7 @@ static int bcm_iproc_i2c_xfer_internal(struct bcm_iproc_i2c_dev *iproc_i2c,
 		 */
 		addr = i2c_8bit_addr_from_msg(msg);
 		/* mark it the last byte out */
-		val = addr | (1 << M_TX_WR_STATUS_SHIFT);
+		val = addr | BIT(M_TX_WR_STATUS_SHIFT);
 		iproc_i2c_wr_reg(iproc_i2c, M_TX_OFFSET, val);
 	}
 
@@ -824,14 +964,14 @@ static int bcm_iproc_i2c_xfer(struct i2c_adapter *adapter,
 
 	ret = bcm_iproc_i2c_xfer_internal(iproc_i2c, msgs, process_call);
 	if (ret) {
-		dev_dbg(iproc_i2c->device, "xfer failed\n");
+		dev_err(iproc_i2c->device, "xfer failed\n");
 		return ret;
 	}
 
 	return num;
 }
 
-static uint32_t bcm_iproc_i2c_functionality(struct i2c_adapter *adap)
+static u32 bcm_iproc_i2c_functionality(struct i2c_adapter *adap)
 {
 	u32 val;
 
@@ -843,8 +983,65 @@ static uint32_t bcm_iproc_i2c_functionality(struct i2c_adapter *adap)
 	return val;
 }
 
+static int bcm_iproc_i2c_reg_slave(struct i2c_client *slave)
+{
+	struct bcm_iproc_i2c_dev *iproc_i2c = i2c_get_adapdata(slave->adapter);
+
+	if (iproc_i2c->slave)
+		return -EBUSY;
+
+	if (slave->flags & I2C_CLIENT_TEN)
+		return -EAFNOSUPPORT;
+
+	iproc_i2c->slave = slave;
+
+	tasklet_init(&iproc_i2c->slave_rx_tasklet, slave_rx_tasklet_fn,
+		     (unsigned long)iproc_i2c);
+
+	bcm_iproc_i2c_slave_init(iproc_i2c, false);
+
+	return 0;
+}
+
+static int bcm_iproc_i2c_unreg_slave(struct i2c_client *slave)
+{
+	struct bcm_iproc_i2c_dev *iproc_i2c = i2c_get_adapdata(slave->adapter);
+	u32 tmp;
+
+	if (!iproc_i2c->slave)
+		return -EINVAL;
+
+	disable_irq(iproc_i2c->irq);
+
+	tasklet_kill(&iproc_i2c->slave_rx_tasklet);
+
+	/* disable all slave interrupts */
+	tmp = iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET);
+	tmp &= ~(IE_S_ALL_INTERRUPT_MASK <<
+			IE_S_ALL_INTERRUPT_SHIFT);
+	iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, tmp);
+
+	/* Erase the slave address programmed */
+	tmp = iproc_i2c_rd_reg(iproc_i2c, S_CFG_SMBUS_ADDR_OFFSET);
+	tmp &= ~BIT(S_CFG_EN_NIC_SMB_ADDR3_SHIFT);
+	iproc_i2c_wr_reg(iproc_i2c, S_CFG_SMBUS_ADDR_OFFSET, tmp);
+
+	/* flush TX/RX FIFOs */
+	tmp = (BIT(S_FIFO_RX_FLUSH_SHIFT) | BIT(S_FIFO_TX_FLUSH_SHIFT));
+	iproc_i2c_wr_reg(iproc_i2c, S_FIFO_CTRL_OFFSET, tmp);
+
+	/* clear all pending slave interrupts */
+	iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, ISR_MASK_SLAVE);
+
+	iproc_i2c->slave = NULL;
+
+	enable_irq(iproc_i2c->irq);
+
+	return 0;
+}
+
 static struct i2c_algorithm bcm_iproc_algo = {
-	.master_xfer = bcm_iproc_i2c_xfer,
+	.xfer = bcm_iproc_i2c_xfer,
 	.functionality = bcm_iproc_i2c_functionality,
 	.reg_slave = bcm_iproc_i2c_reg_slave,
 	.unreg_slave = bcm_iproc_i2c_unreg_slave,
@@ -864,21 +1061,18 @@ static int bcm_iproc_i2c_cfg_speed(struct bcm_iproc_i2c_dev *iproc_i2c)
 				       "clock-frequency", &bus_speed);
 	if (ret < 0) {
 		dev_info(iproc_i2c->device,
-			"unable to interpret clock-frequency DT property\n");
+			 "unable to interpret clock-frequency DT property\n");
 		bus_speed = I2C_MAX_STANDARD_MODE_FREQ;
 	}
 
-	if (bus_speed < I2C_MAX_STANDARD_MODE_FREQ) {
-		dev_err(iproc_i2c->device, "%d Hz bus speed not supported\n",
-			bus_speed);
-		dev_err(iproc_i2c->device,
-			"valid speeds are 100khz and 400khz\n");
-		return -EINVAL;
-	} else if (bus_speed < I2C_MAX_FAST_MODE_FREQ) {
+	if (bus_speed < I2C_MAX_STANDARD_MODE_FREQ)
+		return dev_err_probe(iproc_i2c->device, -EINVAL,
+				     "%d Hz not supported (out of 100-400 kHz range)\n",
+				     bus_speed);
+	else if (bus_speed < I2C_MAX_FAST_MODE_FREQ)
 		bus_speed = I2C_MAX_STANDARD_MODE_FREQ;
-	} else {
+	else
 		bus_speed = I2C_MAX_FAST_MODE_FREQ;
-	}
 
 	iproc_i2c->bus_speed = bus_speed;
 	val = iproc_i2c_rd_reg(iproc_i2c, TIM_CFG_OFFSET);
@@ -893,10 +1087,9 @@ static int bcm_iproc_i2c_cfg_speed(struct bcm_iproc_i2c_dev *iproc_i2c)
 
 static int bcm_iproc_i2c_probe(struct platform_device *pdev)
 {
-	int irq, ret = 0;
 	struct bcm_iproc_i2c_dev *iproc_i2c;
 	struct i2c_adapter *adap;
-	struct resource *res;
+	int irq, ret;
 
 	iproc_i2c = devm_kzalloc(&pdev->dev, sizeof(*iproc_i2c),
 				 GFP_KERNEL);
@@ -909,26 +1102,21 @@ static int bcm_iproc_i2c_probe(struct platform_device *pdev)
 		(enum bcm_iproc_i2c_type)of_device_get_match_data(&pdev->dev);
 	init_completion(&iproc_i2c->done);
 
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	iproc_i2c->base = devm_ioremap_resource(iproc_i2c->device, res);
+	iproc_i2c->base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(iproc_i2c->base))
 		return PTR_ERR(iproc_i2c->base);
 
 	if (iproc_i2c->type == IPROC_I2C_NIC) {
-		res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
-		iproc_i2c->idm_base = devm_ioremap_resource(iproc_i2c->device,
-							    res);
+		iproc_i2c->idm_base = devm_platform_ioremap_resource(pdev, 1);
 		if (IS_ERR(iproc_i2c->idm_base))
 			return PTR_ERR(iproc_i2c->idm_base);
 
 		ret = of_property_read_u32(iproc_i2c->device->of_node,
 					   "brcm,ape-hsls-addr-mask",
 					   &iproc_i2c->ape_addr_mask);
-		if (ret < 0) {
-			dev_err(iproc_i2c->device,
-				"'brcm,ape-hsls-addr-mask' missing\n");
-			return -EINVAL;
-		}
+		if (ret < 0)
+			return dev_err_probe(iproc_i2c->device, ret,
+					     "'brcm,ape-hsls-addr-mask' missing\n");
 
 		spin_lock_init(&iproc_i2c->idm_lock);
 
@@ -937,9 +1125,7 @@ static int bcm_iproc_i2c_probe(struct platform_device *pdev)
 		bcm_iproc_algo.unreg_slave = NULL;
 	}
 
-	ret = bcm_iproc_i2c_init(iproc_i2c);
-	if (ret)
-		return ret;
+	bcm_iproc_i2c_init(iproc_i2c);
 
 	ret = bcm_iproc_i2c_cfg_speed(iproc_i2c);
 	if (ret)
@@ -950,11 +1136,9 @@ static int bcm_iproc_i2c_probe(struct platform_device *pdev)
 		ret = devm_request_irq(iproc_i2c->device, irq,
 				       bcm_iproc_i2c_isr, 0, pdev->name,
 				       iproc_i2c);
-		if (ret < 0) {
-			dev_err(iproc_i2c->device,
-				"unable to request irq %i\n", irq);
-			return ret;
-		}
+		if (ret < 0)
+			return dev_err_probe(iproc_i2c->device, ret,
+					     "unable to request irq %i\n", irq);
 
 		iproc_i2c->irq = irq;
 	} else {
@@ -966,9 +1150,8 @@ static int bcm_iproc_i2c_probe(struct platform_device *pdev)
 
 	adap = &iproc_i2c->adapter;
 	i2c_set_adapdata(adap, iproc_i2c);
-	snprintf(adap->name, sizeof(adap->name),
-		"Broadcom iProc (%s)",
-		of_node_full_name(iproc_i2c->device->of_node));
+	snprintf(adap->name, sizeof(adap->name), "Broadcom iProc (%s)",
+		 of_node_full_name(iproc_i2c->device->of_node));
 	adap->algo = &bcm_iproc_algo;
 	adap->quirks = &bcm_iproc_i2c_quirks;
 	adap->dev.parent = &pdev->dev;
@@ -977,7 +1160,7 @@ static int bcm_iproc_i2c_probe(struct platform_device *pdev)
 	return i2c_add_adapter(adap);
 }
 
-static int bcm_iproc_i2c_remove(struct platform_device *pdev)
+static void bcm_iproc_i2c_remove(struct platform_device *pdev)
 {
 	struct bcm_iproc_i2c_dev *iproc_i2c = platform_get_drvdata(pdev);
 
@@ -993,12 +1176,8 @@ static int bcm_iproc_i2c_remove(struct platform_device *pdev)
 
 	i2c_del_adapter(&iproc_i2c->adapter);
 	bcm_iproc_i2c_enable_disable(iproc_i2c, false);
-
-	return 0;
 }
 
-#ifdef CONFIG_PM_SLEEP
-
 static int bcm_iproc_i2c_suspend(struct device *dev)
 {
 	struct bcm_iproc_i2c_dev *iproc_i2c = dev_get_drvdata(dev);
@@ -1022,16 +1201,13 @@ static int bcm_iproc_i2c_suspend(struct device *dev)
 static int bcm_iproc_i2c_resume(struct device *dev)
 {
 	struct bcm_iproc_i2c_dev *iproc_i2c = dev_get_drvdata(dev);
-	int ret;
 	u32 val;
 
 	/*
 	 * Power domain could have been shut off completely in system deep
 	 * sleep, so re-initialize the block here
 	 */
-	ret = bcm_iproc_i2c_init(iproc_i2c);
-	if (ret)
-		return ret;
+	bcm_iproc_i2c_init(iproc_i2c);
 
 	/* configure to the desired bus speed */
 	val = iproc_i2c_rd_reg(iproc_i2c, TIM_CFG_OFFSET);
@@ -1049,51 +1225,6 @@ static const struct dev_pm_ops bcm_iproc_i2c_pm_ops = {
 	.resume_early = &bcm_iproc_i2c_resume
 };
 
-#define BCM_IPROC_I2C_PM_OPS (&bcm_iproc_i2c_pm_ops)
-#else
-#define BCM_IPROC_I2C_PM_OPS NULL
-#endif /* CONFIG_PM_SLEEP */
-
-
-static int bcm_iproc_i2c_reg_slave(struct i2c_client *slave)
-{
-	struct bcm_iproc_i2c_dev *iproc_i2c = i2c_get_adapdata(slave->adapter);
-
-	if (iproc_i2c->slave)
-		return -EBUSY;
-
-	if (slave->flags & I2C_CLIENT_TEN)
-		return -EAFNOSUPPORT;
-
-	iproc_i2c->slave = slave;
-	bcm_iproc_i2c_slave_init(iproc_i2c, false);
-	return 0;
-}
-
-static int bcm_iproc_i2c_unreg_slave(struct i2c_client *slave)
-{
-	u32 tmp;
-	struct bcm_iproc_i2c_dev *iproc_i2c = i2c_get_adapdata(slave->adapter);
-
-	if (!iproc_i2c->slave)
-		return -EINVAL;
-
-	iproc_i2c->slave = NULL;
-
-	/* disable all slave interrupts */
-	tmp = iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET);
-	tmp &= ~(IE_S_ALL_INTERRUPT_MASK <<
-			IE_S_ALL_INTERRUPT_SHIFT);
-	iproc_i2c_wr_reg(iproc_i2c, IE_OFFSET, tmp);
-
-	/* Erase the slave address programmed */
-	tmp = iproc_i2c_rd_reg(iproc_i2c, S_CFG_SMBUS_ADDR_OFFSET);
-	tmp &= ~BIT(S_CFG_EN_NIC_SMB_ADDR3_SHIFT);
-	iproc_i2c_wr_reg(iproc_i2c, S_CFG_SMBUS_ADDR_OFFSET, tmp);
-
-	return 0;
-}
-
 static const struct of_device_id bcm_iproc_i2c_of_match[] = {
 	{
 		.compatible = "brcm,iproc-i2c",
@@ -1110,7 +1241,7 @@ static struct platform_driver bcm_iproc_i2c_driver = {
 	.driver = {
 		.name = "bcm-iproc-i2c",
 		.of_match_table = bcm_iproc_i2c_of_match,
-		.pm = BCM_IPROC_I2C_PM_OPS,
+		.pm = pm_sleep_ptr(&bcm_iproc_i2c_pm_ops),
 	},
 	.probe = bcm_iproc_i2c_probe,
 	.remove = bcm_iproc_i2c_remove,