Subject: [PATCH net-next-2.6 v2] can: Topcliff: PCH_CAN driver: Add Flow control,

From: Tomoya MORINAGA <[email-masked]>
Date: Mon, 15 Nov 2010 17:30:31 +0900

* Add Flow control
 * Fix Data copy issue (endianness)
 * Add Macro prefix "PCH_"
 * Separate interface register structure
 * Some functions are unified.
 * Change MessageObject indication(PCH_RX_OBJ_START, etc..)
 * Enumerate LEC macro
 * Move MSI processing from open/close to probe/remove processing
 * Use BIT(x)
 * and more...

Signed-off-by: Tomoya MORINAGA <[email-masked]>
---
 drivers/net/can/pch_can.c | 1348 ++++++++++++++++++++-------------------------
 1 files changed, 595 insertions(+), 753 deletions(-)

diff --git a/drivers/net/can/pch_can.c b/drivers/net/can/pch_can.c
index 6727182..6a38593 100644
--- a/drivers/net/can/pch_can.c
+++ b/drivers/net/can/pch_can.c
@@ -1,6 +1,6 @@
 /*
  * Copyright (C) 1999 - 2010 Intel Corporation.
- * Copyright (C) 2010 OKI SEMICONDUCTOR Co., LTD.
+ * Copyright (C) 2010 OKI SEMICONDUCTOR CO., LTD.
  *
  * 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
@@ -32,106 +32,109 @@
 #include <linux/can/dev.h>
 #include <linux/can/error.h>
 
-#define MAX_MSG_OBJ		32
-#define MSG_OBJ_RX		0 /* The receive message object flag. */
-#define MSG_OBJ_TX		1 /* The transmit message object flag. */
-
-#define ENABLE			1 /* The enable flag */
-#define DISABLE			0 /* The disable flag */
-#define CAN_CTRL_INIT		0x0001 /* The INIT bit of CANCONT register. */
-#define CAN_CTRL_IE		0x0002 /* The IE bit of CAN control register */
-#define CAN_CTRL_IE_SIE_EIE	0x000e
-#define CAN_CTRL_CCE		0x0040
-#define CAN_CTRL_OPT		0x0080 /* The OPT bit of CANCONT register. */
-#define CAN_OPT_SILENT		0x0008 /* The Silent bit of CANOPT reg. */
-#define CAN_OPT_LBACK		0x0010 /* The LoopBack bit of CANOPT reg. */
-#define CAN_CMASK_RX_TX_SET	0x00f3
-#define CAN_CMASK_RX_TX_GET	0x0073
-#define CAN_CMASK_ALL		0xff
-#define CAN_CMASK_RDWR		0x80
-#define CAN_CMASK_ARB		0x20
-#define CAN_CMASK_CTRL		0x10
-#define CAN_CMASK_MASK		0x40
-#define CAN_CMASK_NEWDAT	0x04
-#define CAN_CMASK_CLRINTPND	0x08
-
-#define CAN_IF_MCONT_NEWDAT	0x8000
-#define CAN_IF_MCONT_INTPND	0x2000
-#define CAN_IF_MCONT_UMASK	0x1000
-#define CAN_IF_MCONT_TXIE	0x0800
-#define CAN_IF_MCONT_RXIE	0x0400
-#define CAN_IF_MCONT_RMTEN	0x0200
-#define CAN_IF_MCONT_TXRQXT	0x0100
-#define CAN_IF_MCONT_EOB	0x0080
-#define CAN_IF_MCONT_DLC	0x000f
-#define CAN_IF_MCONT_MSGLOST	0x4000
-#define CAN_MASK2_MDIR_MXTD	0xc000
-#define CAN_ID2_DIR		0x2000
-#define CAN_ID_MSGVAL		0x8000
-
-#define CAN_STATUS_INT		0x8000
-#define CAN_IF_CREQ_BUSY	0x8000
-#define CAN_ID2_XTD		0x4000
-
-#define CAN_REC			0x00007f00
-#define CAN_TEC			0x000000ff
-
-#define PCH_RX_OK		0x00000010
-#define PCH_TX_OK		0x00000008
-#define PCH_BUS_OFF		0x00000080
-#define PCH_EWARN		0x00000040
-#define PCH_EPASSIV		0x00000020
-#define PCH_LEC0		0x00000001
-#define PCH_LEC1		0x00000002
-#define PCH_LEC2		0x00000004
-#define PCH_LEC_ALL		(PCH_LEC0 | PCH_LEC1 | PCH_LEC2)
-#define PCH_STUF_ERR		PCH_LEC0
-#define PCH_FORM_ERR		PCH_LEC1
-#define PCH_ACK_ERR		(PCH_LEC0 | PCH_LEC1)
-#define PCH_BIT1_ERR		PCH_LEC2
-#define PCH_BIT0_ERR		(PCH_LEC0 | PCH_LEC2)
-#define PCH_CRC_ERR		(PCH_LEC1 | PCH_LEC2)
+#define PCH_CTRL_INIT		BIT(0) /* The INIT bit of CANCONT register. */
+#define PCH_CTRL_IE		BIT(1) /* The IE bit of CAN control register */
+#define PCH_CTRL_IE_SIE_EIE	(BIT(3) | BIT(2) | BIT(1))
+#define PCH_CTRL_CCE		BIT(6)
+#define PCH_CTRL_OPT		BIT(7) /* The OPT bit of CANCONT register. */
+#define PCH_OPT_SILENT		BIT(3) /* The Silent bit of CANOPT reg. */
+#define PCH_OPT_LBACK		BIT(4) /* The LoopBack bit of CANOPT reg. */
+
+#define PCH_CMASK_RX_TX_SET	0x00f3
+#define PCH_CMASK_RX_TX_GET	0x0073
+#define PCH_CMASK_ALL		0xff
+#define PCH_CMASK_NEWDAT	BIT(2)
+#define PCH_CMASK_CLRINTPND	BIT(3)
+#define PCH_CMASK_CTRL		BIT(4)
+#define PCH_CMASK_ARB		BIT(5)
+#define PCH_CMASK_MASK		BIT(6)
+#define PCH_CMASK_RDWR		BIT(7)
+#define PCH_IF_MCONT_NEWDAT	BIT(15)
+#define PCH_IF_MCONT_MSGLOST	BIT(14)
+#define PCH_IF_MCONT_INTPND	BIT(13)
+#define PCH_IF_MCONT_UMASK	BIT(12)
+#define PCH_IF_MCONT_TXIE	BIT(11)
+#define PCH_IF_MCONT_RXIE	BIT(10)
+#define PCH_IF_MCONT_RMTEN	BIT(9)
+#define PCH_IF_MCONT_TXRQXT	BIT(8)
+#define PCH_IF_MCONT_EOB	BIT(7)
+#define PCH_IF_MCONT_DLC	(BIT(0) | BIT(1) | BIT(2) | BIT(3))
+#define PCH_MASK2_MDIR_MXTD	(BIT(14) | BIT(15))
+#define PCH_ID2_DIR		BIT(13)
+#define PCH_ID2_XTD		BIT(14)
+#define PCH_ID_MSGVAL		BIT(15)
+#define PCH_IF_CREQ_BUSY	BIT(15)
+
+#define PCH_STATUS_INT		0x8000
+#define PCH_REC			0x00007f00
+#define PCH_TEC			0x000000ff
+
+#define PCH_TX_OK		BIT(3)
+#define PCH_RX_OK		BIT(4)
+#define PCH_EPASSIV		BIT(5)
+#define PCH_EWARN		BIT(6)
+#define PCH_BUS_OFF		BIT(7)
 
 /* bit position of certain controller bits. */
-#define BIT_BITT_BRP		0
-#define BIT_BITT_SJW		6
-#define BIT_BITT_TSEG1		8
-#define BIT_BITT_TSEG2		12
-#define BIT_IF1_MCONT_RXIE	10
-#define BIT_IF2_MCONT_TXIE	11
-#define BIT_BRPE_BRPE		6
-#define BIT_ES_TXERRCNT		0
-#define BIT_ES_RXERRCNT		8
-#define MSK_BITT_BRP		0x3f
-#define MSK_BITT_SJW		0xc0
-#define MSK_BITT_TSEG1		0xf00
-#define MSK_BITT_TSEG2		0x7000
-#define MSK_BRPE_BRPE		0x3c0
-#define MSK_BRPE_GET		0x0f
-#define MSK_CTRL_IE_SIE_EIE	0x07
-#define MSK_MCONT_TXIE		0x08
-#define MSK_MCONT_RXIE		0x10
-#define PCH_CAN_NO_TX_BUFF	1
-#define COUNTER_LIMIT		10
-
-#define PCH_CAN_CLK		50000000	/* 50MHz */
-
-/* Define the number of message object.
+#define PCH_BIT_BRP_SHIFT		0
+#define PCH_BIT_SJW_SHIFT		6
+#define PCH_BIT_TSEG1_SHIFT		8
+#define PCH_BIT_TSEG2_SHIFT		12
+#define PCH_BIT_IF1_MCONT_RXIE_SHIFT	10
+#define PCH_BIT_IF2_MCONT_TXIE_SHIFT	11
+#define PCH_BIT_BRPE_BRPE_SHIFT		6
+
+#define PCH_MSK_BITT_BRP		0x3f
+#define PCH_MSK_BRPE_BRPE		0x3c0
+#define PCH_MSK_CTRL_IE_SIE_EIE		0x07
+#define PCH_COUNTER_LIMIT		10
+
+#define PCH_RX_IFREG			0
+#define PCH_TX_IFREG			1
+
+#define PCH_CAN_CLK			50000000	/* 50MHz */
+
+/*
+ * Define the number of message object.
  * PCH CAN communications are done via Message RAM.
- * The Message RAM consists of 32 message objects. */
-#define PCH_RX_OBJ_NUM		26  /* 1~ PCH_RX_OBJ_NUM is Rx*/
-#define PCH_TX_OBJ_NUM		6  /* PCH_RX_OBJ_NUM is RX ~ Tx*/
-#define PCH_OBJ_NUM		(PCH_TX_OBJ_NUM + PCH_RX_OBJ_NUM)
+ * The Message RAM consists of 32 message objects.
+ */
+#define PCH_RX_OBJ_START	1
+#define PCH_RX_OBJ_END		26
+#define PCH_TX_OBJ_START	27
+#define PCH_TX_OBJ_END		32
 
 #define PCH_FIFO_THRESH		16
 
+enum pch_can_err {
+	PCH_STUF_ERR = 1,
+	PCH_FORM_ERR,
+	PCH_ACK_ERR,
+	PCH_BIT1_ERR,
+	PCH_BIT0_ERR,
+	PCH_CRC_ERR,
+	PCH_LEC_ALL,
+};
+
 enum pch_can_mode {
 	PCH_CAN_ENABLE,
 	PCH_CAN_DISABLE,
 	PCH_CAN_ALL,
 	PCH_CAN_NONE,
 	PCH_CAN_STOP,
-	PCH_CAN_RUN
+	PCH_CAN_RUN,
+};
+
+struct pch_can_if_regs {
+	u32 creq;
+	u32 cmask;
+	u32 mask1;
+	u32 mask2;
+	u32 id1;
+	u32 id2;
+	u32 mcont;
+	u32 data[4];
+	u32 rsv[13];
 };
 
 struct pch_can_regs {
@@ -142,61 +145,44 @@ struct pch_can_regs {
 	u32 intr;
 	u32 opt;
 	u32 brpe;
-	u32 reserve1;
-	u32 if1_creq;
-	u32 if1_cmask;
-	u32 if1_mask1;
-	u32 if1_mask2;
-	u32 if1_id1;
-	u32 if1_id2;
-	u32 if1_mcont;
-	u32 if1_dataa1;
-	u32 if1_dataa2;
-	u32 if1_datab1;
-	u32 if1_datab2;
-	u32 reserve2;
-	u32 reserve3[12];
-	u32 if2_creq;
-	u32 if2_cmask;
-	u32 if2_mask1;
-	u32 if2_mask2;
-	u32 if2_id1;
-	u32 if2_id2;
-	u32 if2_mcont;
-	u32 if2_dataa1;
-	u32 if2_dataa2;
-	u32 if2_datab1;
-	u32 if2_datab2;
-	u32 reserve4;
-	u32 reserve5[20];
+	u32 reserve;
+	struct pch_can_if_regs ifregs[2]; /* [0]=if1  [1]=if2 */
+	u32 reserve1[8];
 	u32 treq1;
 	u32 treq2;
-	u32 reserve6[2];
-	u32 reserve7[56];
-	u32 reserve8[3];
+	u32 reserve2[6];
+	u32 data1;
+	u32 data2;
+	u32 reserve3[6];
+	u32 canipend1;
+	u32 canipend2;
+	u32 reserve4[6];
+	u32 canmval1;
+	u32 canmval2;
+	u32 reserve5[37];
 	u32 srst;
 };
 
 struct pch_can_priv {
 	struct can_priv can;
-	unsigned int can_num;
 	struct pci_dev *dev;
-	unsigned int tx_enable[MAX_MSG_OBJ];
-	unsigned int rx_enable[MAX_MSG_OBJ];
-	unsigned int rx_link[MAX_MSG_OBJ];
+	unsigned int tx_enable[PCH_TX_OBJ_END];
+	unsigned int rx_enable[PCH_TX_OBJ_END];
+	unsigned int rx_link[PCH_TX_OBJ_END];
 	unsigned int int_enables;
 	unsigned int int_stat;
 	struct net_device *ndev;
-	spinlock_t msgif_reg_lock; /* Message Interface Registers Access Lock*/
-	unsigned int msg_obj[MAX_MSG_OBJ];
+	spinlock_t msgif_reg_lock; /* Message Interface Registers Access Lock */
+	unsigned int msg_obj[PCH_TX_OBJ_END];
 	struct pch_can_regs __iomem *regs;
 	struct napi_struct napi;
 	unsigned int tx_obj;	/* Point next Tx Obj index */
 	unsigned int use_msi;
+	unsigned int netif_stop;
 };
 
 static struct can_bittiming_const pch_can_bittiming_const = {
-	.name = KBUILD_MODNAME,
+	.name = "pch_can",
 	.tseg1_min = 1,
 	.tseg1_max = 16,
 	.tseg2_min = 1,
@@ -228,15 +214,15 @@ static void pch_can_set_run_mode(struct pch_can_priv *priv,
 {
 	switch (mode) {
 	case PCH_CAN_RUN:
-		pch_can_bit_clear(&priv->regs->cont, CAN_CTRL_INIT);
+		pch_can_bit_clear(&priv->regs->cont, PCH_CTRL_INIT);
 		break;
 
 	case PCH_CAN_STOP:
-		pch_can_bit_set(&priv->regs->cont, CAN_CTRL_INIT);
+		pch_can_bit_set(&priv->regs->cont, PCH_CTRL_INIT);
 		break;
 
 	default:
-		dev_err(&priv->ndev->dev, "%s -> Invalid Mode.\n", __func__);
+		netdev_err(priv->ndev, "%s -> Invalid Mode.\n", __func__);
 		break;
 	}
 }
@@ -246,357 +232,184 @@ static void pch_can_set_optmode(struct pch_can_priv *priv)
 	u32 reg_val = ioread32(&priv->regs->opt);
 
 	if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
-		reg_val |= CAN_OPT_SILENT;
+		reg_val |= PCH_OPT_SILENT;
 
 	if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)
-		reg_val |= CAN_OPT_LBACK;
+		reg_val |= PCH_OPT_LBACK;
 
-	pch_can_bit_set(&priv->regs->cont, CAN_CTRL_OPT);
+	pch_can_bit_set(&priv->regs->cont, PCH_CTRL_OPT);
 	iowrite32(reg_val, &priv->regs->opt);
 }
 
-static void pch_can_set_int_custom(struct pch_can_priv *priv)
+static void pch_can_rw_msg_obj(void __iomem *creq_addr, u32 num)
 {
-	/* Clearing the IE, SIE and EIE bits of Can control register. */
-	pch_can_bit_clear(&priv->regs->cont, CAN_CTRL_IE_SIE_EIE);
-
-	/* Appropriately setting them. */
-	pch_can_bit_set(&priv->regs->cont,
-			((priv->int_enables & MSK_CTRL_IE_SIE_EIE) << 1));
-}
+	u32 counter = PCH_COUNTER_LIMIT;
+	u32 ifx_creq;
 
-/* This function retrieves interrupt enabled for the CAN device. */
-static void pch_can_get_int_enables(struct pch_can_priv *priv, u32 *enables)
-{
-	/* Obtaining the status of IE, SIE and EIE interrupt bits. */
-	*enables = ((ioread32(&priv->regs->cont) & CAN_CTRL_IE_SIE_EIE) >> 1);
+	iowrite32(num, creq_addr);
+	while (counter) {
+		ifx_creq = ioread32(creq_addr) & PCH_IF_CREQ_BUSY;
+		if (!ifx_creq)
+			break;
+		counter--;
+		udelay(1);
+	}
+	if (!counter)
+		pr_err("%s:IF1 BUSY Flag is set forever.\n", __func__);
 }
 
 static void pch_can_set_int_enables(struct pch_can_priv *priv,
 				    enum pch_can_mode interrupt_no)
 {
 	switch (interrupt_no) {
-	case PCH_CAN_ENABLE:
-		pch_can_bit_set(&priv->regs->cont, CAN_CTRL_IE);
-		break;
-
 	case PCH_CAN_DISABLE:
-		pch_can_bit_clear(&priv->regs->cont, CAN_CTRL_IE);
+		pch_can_bit_clear(&priv->regs->cont, PCH_CTRL_IE);
 		break;
 
 	case PCH_CAN_ALL:
-		pch_can_bit_set(&priv->regs->cont, CAN_CTRL_IE_SIE_EIE);
+		pch_can_bit_set(&priv->regs->cont, PCH_CTRL_IE_SIE_EIE);
 		break;
 
 	case PCH_CAN_NONE:
-		pch_can_bit_clear(&priv->regs->cont, CAN_CTRL_IE_SIE_EIE);
+		pch_can_bit_clear(&priv->regs->cont, PCH_CTRL_IE_SIE_EIE);
 		break;
 
 	default:
-		dev_err(&priv->ndev->dev, "Invalid interrupt number.\n");
+		netdev_err(priv->ndev, "Invalid interrupt number.\n");
 		break;
 	}
 }
 
-static void pch_can_check_if_busy(u32 __iomem *creq_addr, u32 num)
-{
-	u32 counter = COUNTER_LIMIT;
-	u32 ifx_creq;
-
-	iowrite32(num, creq_addr);
-	while (counter) {
-		ifx_creq = ioread32(creq_addr) & CAN_IF_CREQ_BUSY;
-		if (!ifx_creq)
-			break;
-		counter--;
-		udelay(1);
-	}
-	if (!counter)
-		pr_err("%s:IF1 BUSY Flag is set forever.\n", __func__);
-}
-
-static void pch_can_set_rx_enable(struct pch_can_priv *priv, u32 buff_num,
-				  u32 set)
-{
-	unsigned long flags;
-
-	spin_lock_irqsave(&priv->msgif_reg_lock, flags);
-	/* Reading the receive buffer data from RAM to Interface1 registers */
-	iowrite32(CAN_CMASK_RX_TX_GET, &priv->regs->if1_cmask);
-	pch_can_check_if_busy(&priv->regs->if1_creq, buff_num);
-
-	/* Setting the IF1MASK1 register to access MsgVal and RxIE bits */
-	iowrite32(CAN_CMASK_RDWR | CAN_CMASK_ARB | CAN_CMASK_CTRL,
-		  &priv->regs->if1_cmask);
-
-	if (set == ENABLE) {
-		/* Setting the MsgVal and RxIE bits */
-		pch_can_bit_set(&priv->regs->if1_mcont, CAN_IF_MCONT_RXIE);
-		pch_can_bit_set(&priv->regs->if1_id2, CAN_ID_MSGVAL);
-
-	} else if (set == DISABLE) {
-		/* Resetting the MsgVal and RxIE bits */
-		pch_can_bit_clear(&priv->regs->if1_mcont, CAN_IF_MCONT_RXIE);
-		pch_can_bit_clear(&priv->regs->if1_id2, CAN_ID_MSGVAL);
-	}
-
-	pch_can_check_if_busy(&priv->regs->if1_creq, buff_num);
-	spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
-}
-
-static void pch_can_rx_enable_all(struct pch_can_priv *priv)
-{
-	int i;
-
-	/* Traversing to obtain the object configured as receivers. */
-	for (i = 0; i < PCH_OBJ_NUM; i++) {
-		if (priv->msg_obj[i] == MSG_OBJ_RX)
-			pch_can_set_rx_enable(priv, i + 1, ENABLE);
-	}
-}
-
-static void pch_can_rx_disable_all(struct pch_can_priv *priv)
+static void pch_can_set_rxtx(struct pch_can_priv *priv, u32 buff_num,
+				    u32 set, u32 dir)
 {
-	int i;
-
-	/* Traversing to obtain the object configured as receivers. */
-	for (i = 0; i < PCH_OBJ_NUM; i++) {
-		if (priv->msg_obj[i] == MSG_OBJ_RX)
-			pch_can_set_rx_enable(priv, i + 1, DISABLE);
-	}
-}
+	u32 ie;
 
-static void pch_can_set_tx_enable(struct pch_can_priv *priv, u32 buff_num,
-				 u32 set)
-{
-	unsigned long flags;
+	if (dir)
+		ie = PCH_IF_MCONT_TXIE;
+	else
+		ie = PCH_IF_MCONT_RXIE;
 
-	spin_lock_irqsave(&priv->msgif_reg_lock, flags);
 	/* Reading the Msg buffer from Message RAM to Interface2 registers. */
-	iowrite32(CAN_CMASK_RX_TX_GET, &priv->regs->if2_cmask);
-	pch_can_check_if_busy(&priv->regs->if2_creq, buff_num);
+	iowrite32(PCH_CMASK_RX_TX_GET, &priv->regs->ifregs[dir].cmask);
+	pch_can_rw_msg_obj(&priv->regs->ifregs[dir].creq, buff_num);
 
 	/* Setting the IF2CMASK register for accessing the
 		MsgVal and TxIE bits */
-	iowrite32(CAN_CMASK_RDWR | CAN_CMASK_ARB | CAN_CMASK_CTRL,
-		 &priv->regs->if2_cmask);
+	iowrite32(PCH_CMASK_RDWR | PCH_CMASK_ARB | PCH_CMASK_CTRL,
+		 &priv->regs->ifregs[dir].cmask);
 
-	if (set == ENABLE) {
+	if (set) {
 		/* Setting the MsgVal and TxIE bits */
-		pch_can_bit_set(&priv->regs->if2_mcont, CAN_IF_MCONT_TXIE);
-		pch_can_bit_set(&priv->regs->if2_id2, CAN_ID_MSGVAL);
-	} else if (set == DISABLE) {
+		pch_can_bit_set(&priv->regs->ifregs[dir].mcont, ie);
+		pch_can_bit_set(&priv->regs->ifregs[dir].id2, PCH_ID_MSGVAL);
+	} else {
 		/* Resetting the MsgVal and TxIE bits. */
-		pch_can_bit_clear(&priv->regs->if2_mcont, CAN_IF_MCONT_TXIE);
-		pch_can_bit_clear(&priv->regs->if2_id2, CAN_ID_MSGVAL);
+		pch_can_bit_clear(&priv->regs->ifregs[dir].mcont, ie);
+		pch_can_bit_clear(&priv->regs->ifregs[dir].id2, PCH_ID_MSGVAL);
 	}
 
-	pch_can_check_if_busy(&priv->regs->if2_creq, buff_num);
-	spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
+	pch_can_rw_msg_obj(&priv->regs->ifregs[dir].creq, buff_num);
 }
 
-static void pch_can_tx_enable_all(struct pch_can_priv *priv)
+static void pch_can_set_rx_all(struct pch_can_priv *priv, u32 set)
 {
 	int i;
 
-	/* Traversing to obtain the object configured as transmit object. */
-	for (i = 0; i < PCH_OBJ_NUM; i++) {
-		if (priv->msg_obj[i] == MSG_OBJ_TX)
-			pch_can_set_tx_enable(priv, i + 1, ENABLE);
-	}
+	/* Traversing to obtain the object configured as receivers. */
+	for (i = PCH_RX_OBJ_START; i <= PCH_RX_OBJ_END; i++)
+		pch_can_set_rxtx(priv, i, set, PCH_RX_IFREG);
 }
 
-static void pch_can_tx_disable_all(struct pch_can_priv *priv)
+static void pch_can_set_tx_all(struct pch_can_priv *priv, u32 set)
 {
 	int i;
 
-	/* Traversing to obtain the object configured as transmit object. */
-	for (i = 0; i < PCH_OBJ_NUM; i++) {
-		if (priv->msg_obj[i] == MSG_OBJ_TX)
-			pch_can_set_tx_enable(priv, i + 1, DISABLE);
-	}
-}
-
-static void pch_can_get_rx_enable(struct pch_can_priv *priv, u32 buff_num,
-				 u32 *enable)
-{
-	unsigned long flags;
-
-	spin_lock_irqsave(&priv->msgif_reg_lock, flags);
-	iowrite32(CAN_CMASK_RX_TX_GET, &priv->regs->if1_cmask);
-	pch_can_check_if_busy(&priv->regs->if1_creq, buff_num);
-
-	if (((ioread32(&priv->regs->if1_id2)) & CAN_ID_MSGVAL) &&
-			((ioread32(&priv->regs->if1_mcont)) &
-			CAN_IF_MCONT_RXIE))
-		*enable = ENABLE;
-	else
-		*enable = DISABLE;
-	spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
-}
-
-static void pch_can_get_tx_enable(struct pch_can_priv *priv, u32 buff_num,
-				 u32 *enable)
-{
-	unsigned long flags;
-
-	spin_lock_irqsave(&priv->msgif_reg_lock, flags);
-	iowrite32(CAN_CMASK_RX_TX_GET, &priv->regs->if2_cmask);
-	pch_can_check_if_busy(&priv->regs->if2_creq, buff_num);
-
-	if (((ioread32(&priv->regs->if2_id2)) & CAN_ID_MSGVAL) &&
-			((ioread32(&priv->regs->if2_mcont)) &
-			CAN_IF_MCONT_TXIE)) {
-		*enable = ENABLE;
-	} else {
-		*enable = DISABLE;
-	}
-	spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
+	/* Traversing to obtain the object configured as receivers. */
+	for (i = PCH_TX_OBJ_START; i <= PCH_TX_OBJ_END; i++)
+		pch_can_set_rxtx(priv, i, set, PCH_TX_IFREG);
 }
 
-static int pch_can_int_pending(struct pch_can_priv *priv)
+static u32 pch_can_int_pending(struct pch_can_priv *priv)
 {
 	return ioread32(&priv->regs->intr) & 0xffff;
 }
 
-static void pch_can_set_rx_buffer_link(struct pch_can_priv *priv,
-				       u32 buffer_num, u32 set)
-{
-	unsigned long flags;
-
-	spin_lock_irqsave(&priv->msgif_reg_lock, flags);
-	iowrite32(CAN_CMASK_RX_TX_GET, &priv->regs->if1_cmask);
-	pch_can_check_if_busy(&priv->regs->if1_creq, buffer_num);
-	iowrite32(CAN_CMASK_RDWR | CAN_CMASK_CTRL, &priv->regs->if1_cmask);
-	if (set == ENABLE)
-		pch_can_bit_clear(&priv->regs->if1_mcont, CAN_IF_MCONT_EOB);
-	else
-		pch_can_bit_set(&priv->regs->if1_mcont, CAN_IF_MCONT_EOB);
-
-	pch_can_check_if_busy(&priv->regs->if1_creq, buffer_num);
-	spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
-}
-
-static void pch_can_get_rx_buffer_link(struct pch_can_priv *priv,
-				       u32 buffer_num, u32 *link)
+static void pch_can_clear_if_buffers(struct pch_can_priv *priv)
 {
-	unsigned long flags;
-
-	spin_lock_irqsave(&priv->msgif_reg_lock, flags);
-	iowrite32(CAN_CMASK_RX_TX_GET, &priv->regs->if1_cmask);
-	pch_can_check_if_busy(&priv->regs->if1_creq, buffer_num);
-
-	if (ioread32(&priv->regs->if1_mcont) & CAN_IF_MCONT_EOB)
-		*link = DISABLE;
-	else
-		*link = ENABLE;
-	spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
-}
-
-static void pch_can_clear_buffers(struct pch_can_priv *priv)
-{
-	int i;
-
-	for (i = 0; i < PCH_RX_OBJ_NUM; i++) {
-		iowrite32(CAN_CMASK_RX_TX_SET, &priv->regs->if1_cmask);
-		iowrite32(0xffff, &priv->regs->if1_mask1);
-		iowrite32(0xffff, &priv->regs->if1_mask2);
-		iowrite32(0x0, &priv->regs->if1_id1);
-		iowrite32(0x0, &priv->regs->if1_id2);
-		iowrite32(0x0, &priv->regs->if1_mcont);
-		iowrite32(0x0, &priv->regs->if1_dataa1);
-		iowrite32(0x0, &priv->regs->if1_dataa2);
-		iowrite32(0x0, &priv->regs->if1_datab1);
-		iowrite32(0x0, &priv->regs->if1_datab2);
-		iowrite32(CAN_CMASK_RDWR | CAN_CMASK_MASK |
-			  CAN_CMASK_ARB | CAN_CMASK_CTRL,
-			  &priv->regs->if1_cmask);
-		pch_can_check_if_busy(&priv->regs->if1_creq, i+1);
-	}
-
-	for (i = i;  i < PCH_OBJ_NUM; i++) {
-		iowrite32(CAN_CMASK_RX_TX_SET, &priv->regs->if2_cmask);
-		iowrite32(0xffff, &priv->regs->if2_mask1);
-		iowrite32(0xffff, &priv->regs->if2_mask2);
-		iowrite32(0x0, &priv->regs->if2_id1);
-		iowrite32(0x0, &priv->regs->if2_id2);
-		iowrite32(0x0, &priv->regs->if2_mcont);
-		iowrite32(0x0, &priv->regs->if2_dataa1);
-		iowrite32(0x0, &priv->regs->if2_dataa2);
-		iowrite32(0x0, &priv->regs->if2_datab1);
-		iowrite32(0x0, &priv->regs->if2_datab2);
-		iowrite32(CAN_CMASK_RDWR | CAN_CMASK_MASK |
-			  CAN_CMASK_ARB | CAN_CMASK_CTRL,
-			  &priv->regs->if2_cmask);
-		pch_can_check_if_busy(&priv->regs->if2_creq, i+1);
+	int i; /* Msg Obj ID (1~32) */
+
+	for (i = PCH_RX_OBJ_START; i <= PCH_TX_OBJ_END; i++) {
+		iowrite32(PCH_CMASK_RX_TX_SET, &priv->regs->ifregs[0].cmask);
+		iowrite32(0xffff, &priv->regs->ifregs[0].mask1);
+		iowrite32(0xffff, &priv->regs->ifregs[0].mask2);
+		iowrite32(0x0, &priv->regs->ifregs[0].id1);
+		iowrite32(0x0, &priv->regs->ifregs[0].id2);
+		iowrite32(0x0, &priv->regs->ifregs[0].mcont);
+		iowrite32(0x0, &priv->regs->ifregs[0].data[0]);
+		iowrite32(0x0, &priv->regs->ifregs[0].data[1]);
+		iowrite32(0x0, &priv->regs->ifregs[0].data[2]);
+		iowrite32(0x0, &priv->regs->ifregs[0].data[3]);
+		iowrite32(PCH_CMASK_RDWR | PCH_CMASK_MASK |
+			  PCH_CMASK_ARB | PCH_CMASK_CTRL,
+			  &priv->regs->ifregs[0].cmask);
+		pch_can_rw_msg_obj(&priv->regs->ifregs[0].creq, i);
 	}
 }
 
 static void pch_can_config_rx_tx_buffers(struct pch_can_priv *priv)
 {
 	int i;
-	unsigned long flags;
-
-	spin_lock_irqsave(&priv->msgif_reg_lock, flags);
 
-	for (i = 0; i < PCH_OBJ_NUM; i++) {
-		if (priv->msg_obj[i] == MSG_OBJ_RX) {
-			iowrite32(CAN_CMASK_RX_TX_GET,
-				&priv->regs->if1_cmask);
-			pch_can_check_if_busy(&priv->regs->if1_creq, i+1);
+	for (i = PCH_RX_OBJ_START; i <= PCH_RX_OBJ_END; i++) {
+		iowrite32(PCH_CMASK_RX_TX_GET, &priv->regs->ifregs[0].cmask);
+		pch_can_rw_msg_obj(&priv->regs->ifregs[0].creq, i);
 
-			iowrite32(0x0, &priv->regs->if1_id1);
-			iowrite32(0x0, &priv->regs->if1_id2);
+		iowrite32(0x0, &priv->regs->ifregs[0].id1);
+		iowrite32(0x0, &priv->regs->ifregs[0].id2);
 
-			pch_can_bit_set(&priv->regs->if1_mcont,
-					CAN_IF_MCONT_UMASK);
+		pch_can_bit_set(&priv->regs->ifregs[0].mcont,
+				PCH_IF_MCONT_UMASK);
 
-			/* Set FIFO mode set to 0 except last Rx Obj*/
-			pch_can_bit_clear(&priv->regs->if1_mcont,
-					  CAN_IF_MCONT_EOB);
-			/* In case FIFO mode, Last EoB of Rx Obj must be 1 */
-			if (i == (PCH_RX_OBJ_NUM - 1))
-				pch_can_bit_set(&priv->regs->if1_mcont,
-						  CAN_IF_MCONT_EOB);
+		if (i == PCH_RX_OBJ_END)
+			pch_can_bit_set(&priv->regs->ifregs[0].mcont,
+					PCH_IF_MCONT_EOB);
+		else
+			pch_can_bit_clear(&priv->regs->ifregs[0].mcont,
+					  PCH_IF_MCONT_EOB);
 
-			iowrite32(0, &priv->regs->if1_mask1);
-			pch_can_bit_clear(&priv->regs->if1_mask2,
-					  0x1fff | CAN_MASK2_MDIR_MXTD);
+		iowrite32(0, &priv->regs->ifregs[0].mask1);
+		pch_can_bit_clear(&priv->regs->ifregs[0].mask2,
+				  0x1fff | PCH_MASK2_MDIR_MXTD);
 
-			/* Setting CMASK for writing */
-			iowrite32(CAN_CMASK_RDWR | CAN_CMASK_MASK |
-				  CAN_CMASK_ARB | CAN_CMASK_CTRL,
-				  &priv->regs->if1_cmask);
+		/* Setting CMASK for writing */
+		iowrite32(PCH_CMASK_RDWR | PCH_CMASK_MASK | PCH_CMASK_ARB |
+			  PCH_CMASK_CTRL, &priv->regs->ifregs[0].cmask);
 
-			pch_can_check_if_busy(&priv->regs->if1_creq, i+1);
-		} else if (priv->msg_obj[i] == MSG_OBJ_TX) {
-			iowrite32(CAN_CMASK_RX_TX_GET,
-				&priv->regs->if2_cmask);
-			pch_can_check_if_busy(&priv->regs->if2_creq, i+1);
+		pch_can_rw_msg_obj(&priv->regs->ifregs[0].creq, i);
+	}
 
-			/* Resetting DIR bit for reception */
-			iowrite32(0x0, &priv->regs->if2_id1);
-			iowrite32(0x0, &priv->regs->if2_id2);
-			pch_can_bit_set(&priv->regs->if2_id2, CAN_ID2_DIR);
+	for (i = PCH_TX_OBJ_START; i <= PCH_TX_OBJ_END; i++) {
+		iowrite32(PCH_CMASK_RX_TX_GET, &priv->regs->ifregs[1].cmask);
+		pch_can_rw_msg_obj(&priv->regs->ifregs[1].creq, i);
 
-			/* Setting EOB bit for transmitter */
-			iowrite32(CAN_IF_MCONT_EOB, &priv->regs->if2_mcont);
+		/* Resetting DIR bit for reception */
+		iowrite32(0x0, &priv->regs->ifregs[1].id1);
+		iowrite32(PCH_ID2_DIR, &priv->regs->ifregs[1].id2);
 
-			pch_can_bit_set(&priv->regs->if2_mcont,
-					CAN_IF_MCONT_UMASK);
+		/* Setting EOB bit for transmitter */
+		iowrite32(PCH_IF_MCONT_EOB | PCH_IF_MCONT_UMASK,
+			  &priv->regs->ifregs[1].mcont);
 
-			iowrite32(0, &priv->regs->if2_mask1);
-			pch_can_bit_clear(&priv->regs->if2_mask2, 0x1fff);
+		iowrite32(0, &priv->regs->ifregs[1].mask1);
+		pch_can_bit_clear(&priv->regs->ifregs[1].mask2, 0x1fff);
 
-			/* Setting CMASK for writing */
-			iowrite32(CAN_CMASK_RDWR | CAN_CMASK_MASK |
-				  CAN_CMASK_ARB | CAN_CMASK_CTRL,
-				  &priv->regs->if2_cmask);
+		/* Setting CMASK for writing */
+		iowrite32(PCH_CMASK_RDWR | PCH_CMASK_MASK | PCH_CMASK_ARB |
+			  PCH_CMASK_CTRL, &priv->regs->ifregs[1].cmask);
 
-			pch_can_check_if_busy(&priv->regs->if2_creq, i+1);
-		}
+		pch_can_rw_msg_obj(&priv->regs->ifregs[1].creq, i);
 	}
-	spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
 }
 
 static void pch_can_init(struct pch_can_priv *priv)
@@ -605,7 +418,7 @@ static void pch_can_init(struct pch_can_priv *priv)
 	pch_can_set_run_mode(priv, PCH_CAN_STOP);
 
 	/* Clearing all the message object buffers. */
-	pch_can_clear_buffers(priv);
+	pch_can_clear_if_buffers(priv);
 
 	/* Configuring the respective message object as either rx/tx object. */
 	pch_can_config_rx_tx_buffers(priv);
@@ -623,57 +436,53 @@ static void pch_can_release(struct pch_can_priv *priv)
 	pch_can_set_int_enables(priv, PCH_CAN_NONE);
 
 	/* Disabling all the receive object. */
-	pch_can_rx_disable_all(priv);
+	pch_can_set_rx_all(priv, 0);
 
 	/* Disabling all the transmit object. */
-	pch_can_tx_disable_all(priv);
+	pch_can_set_tx_all(priv, 0);
 }
 
 /* This function clears interrupt(s) from the CAN device. */
 static void pch_can_int_clr(struct pch_can_priv *priv, u32 mask)
 {
-	if (mask == CAN_STATUS_INT) {
-		ioread32(&priv->regs->stat);
-		return;
-	}
-
 	/* Clear interrupt for transmit object */
-	if (priv->msg_obj[mask - 1] == MSG_OBJ_TX) {
-		/* Setting CMASK for clearing interrupts for
-					 frame transmission. */
-		iowrite32(CAN_CMASK_RDWR | CAN_CMASK_CTRL | CAN_CMASK_ARB,
-			  &priv->regs->if2_cmask);
-
-		/* Resetting the ID registers. */
-		pch_can_bit_set(&priv->regs->if2_id2,
-			       CAN_ID2_DIR | (0x7ff << 2));
-		iowrite32(0x0, &priv->regs->if2_id1);
-
-		/* Claring NewDat, TxRqst & IntPnd */
-		pch_can_bit_clear(&priv->regs->if2_mcont,
-				  CAN_IF_MCONT_NEWDAT | CAN_IF_MCONT_INTPND |
-				  CAN_IF_MCONT_TXRQXT);
-		pch_can_check_if_busy(&priv->regs->if2_creq, mask);
-	} else if (priv->msg_obj[mask - 1] == MSG_OBJ_RX) {
+	if ((mask >= PCH_RX_OBJ_START) && (mask <= PCH_RX_OBJ_END)) {
 		/* Setting CMASK for clearing the reception interrupts. */
-		iowrite32(CAN_CMASK_RDWR | CAN_CMASK_CTRL | CAN_CMASK_ARB,
-			  &priv->regs->if1_cmask);
+		iowrite32(PCH_CMASK_RDWR | PCH_CMASK_CTRL | PCH_CMASK_ARB,
+			  &priv->regs->ifregs[0].cmask);
 
 		/* Clearing the Dir bit. */
-		pch_can_bit_clear(&priv->regs->if1_id2, CAN_ID2_DIR);
+		pch_can_bit_clear(&priv->regs->ifregs[0].id2, PCH_ID2_DIR);
 
 		/* Clearing NewDat & IntPnd */
-		pch_can_bit_clear(&priv->regs->if1_mcont,
-				  CAN_IF_MCONT_NEWDAT | CAN_IF_MCONT_INTPND);
+		pch_can_bit_clear(&priv->regs->ifregs[0].mcont,
+				  PCH_IF_MCONT_NEWDAT | PCH_IF_MCONT_INTPND);
+
+		pch_can_rw_msg_obj(&priv->regs->ifregs[0].creq, mask);
+	} else if ((mask >= PCH_TX_OBJ_START) && (mask <= PCH_TX_OBJ_END)) {
+		/*
+		 * Setting CMASK for clearing interrupts for frame transmission.
+		 */
+		iowrite32(PCH_CMASK_RDWR | PCH_CMASK_CTRL | PCH_CMASK_ARB,
+			  &priv->regs->ifregs[1].cmask);
+
+		/* Resetting the ID registers. */
+		pch_can_bit_set(&priv->regs->ifregs[1].id2,
+			       PCH_ID2_DIR | (0x7ff << 2));
+		iowrite32(0x0, &priv->regs->ifregs[1].id1);
 
-		pch_can_check_if_busy(&priv->regs->if1_creq, mask);
+		/* Claring NewDat, TxRqst & IntPnd */
+		pch_can_bit_clear(&priv->regs->ifregs[1].mcont,
+				  PCH_IF_MCONT_NEWDAT | PCH_IF_MCONT_INTPND |
+				  PCH_IF_MCONT_TXRQXT);
+		pch_can_rw_msg_obj(&priv->regs->ifregs[1].creq, mask);
 	}
 }
 
-static int pch_can_get_buffer_status(struct pch_can_priv *priv)
+static u32 pch_can_get_buffer_status(struct pch_can_priv *priv)
 {
 	return (ioread32(&priv->regs->treq1) & 0xffff) |
-	       ((ioread32(&priv->regs->treq2) & 0xffff) << 16);
+	       (ioread32(&priv->regs->treq2) << 16);
 }
 
 static void pch_can_reset(struct pch_can_priv *priv)
@@ -688,7 +497,7 @@ static void pch_can_error(struct net_device *ndev, u32 status)
 	struct sk_buff *skb;
 	struct pch_can_priv *priv = netdev_priv(ndev);
 	struct can_frame *cf;
-	u32 errc;
+	u32 errc, lec;
 	struct net_device_stats *stats = &(priv->ndev->stats);
 	enum can_state state = priv->can.state;
 
@@ -697,13 +506,11 @@ static void pch_can_error(struct net_device *ndev, u32 status)
 		return;
 
 	if (status & PCH_BUS_OFF) {
-		pch_can_tx_disable_all(priv);
-		pch_can_rx_disable_all(priv);
+		pch_can_set_tx_all(priv, 0);
+		pch_can_set_rx_all(priv, 0);
 		state = CAN_STATE_BUS_OFF;
 		cf->can_id |= CAN_ERR_BUSOFF;
 		can_bus_off(ndev);
-		pch_can_set_run_mode(priv, PCH_CAN_RUN);
-		dev_err(&ndev->dev, "%s -> Bus Off occurres.\n", __func__);
 	}
 
 	/* Warning interrupt. */
@@ -712,11 +519,11 @@ static void pch_can_error(struct net_device *ndev, u32 status)
 		priv->can.can_stats.error_warning++;
 		cf->can_id |= CAN_ERR_CRTL;
 		errc = ioread32(&priv->regs->errc);
-		if (((errc & CAN_REC) >> 8) > 96)
+		if (((errc & PCH_REC) >> 8) > 96)
 			cf->data[1] |= CAN_ERR_CRTL_RX_WARNING;
-		if ((errc & CAN_TEC) > 96)
+		if ((errc & PCH_TEC) > 96)
 			cf->data[1] |= CAN_ERR_CRTL_TX_WARNING;
-		dev_warn(&ndev->dev,
+		netdev_dbg(ndev,
 			"%s -> Error Counter is more than 96.\n", __func__);
 	}
 	/* Error passive interrupt. */
@@ -725,45 +532,52 @@ static void pch_can_error(struct net_device *ndev, u32 status)
 		state = CAN_STATE_ERROR_PASSIVE;
 		cf->can_id |= CAN_ERR_CRTL;
 		errc = ioread32(&priv->regs->errc);
-		if (((errc & CAN_REC) >> 8) > 127)
+		if (((errc & PCH_REC) >> 8) > 127)
 			cf->data[1] |= CAN_ERR_CRTL_RX_PASSIVE;
-		if ((errc & CAN_TEC) > 127)
+		if ((errc & PCH_TEC) > 127)
 			cf->data[1] |= CAN_ERR_CRTL_TX_PASSIVE;
-		dev_err(&ndev->dev,
+		netdev_dbg(ndev,
 			"%s -> CAN controller is ERROR PASSIVE .\n", __func__);
 	}
 
-	if (status & PCH_LEC_ALL) {
+	lec = status & PCH_LEC_ALL;
+	switch (lec) {
+	case PCH_STUF_ERR:
+		cf->data[2] |= CAN_ERR_PROT_STUFF;
 		priv->can.can_stats.bus_error++;
 		stats->rx_errors++;
-		switch (status & PCH_LEC_ALL) {
-		case PCH_STUF_ERR:
-			cf->data[2] |= CAN_ERR_PROT_STUFF;
-			break;
-		case PCH_FORM_ERR:
-			cf->data[2] |= CAN_ERR_PROT_FORM;
-			break;
-		case PCH_ACK_ERR:
-			cf->data[2] |= CAN_ERR_PROT_LOC_ACK |
-				       CAN_ERR_PROT_LOC_ACK_DEL;
-			break;
-		case PCH_BIT1_ERR:
-		case PCH_BIT0_ERR:
-			cf->data[2] |= CAN_ERR_PROT_BIT;
-			break;
-		case PCH_CRC_ERR:
-			cf->data[2] |= CAN_ERR_PROT_LOC_CRC_SEQ |
-				       CAN_ERR_PROT_LOC_CRC_DEL;
-			break;
-		default:
-			iowrite32(status | PCH_LEC_ALL, &priv->regs->stat);
-			break;
-		}
-
+		break;
+	case PCH_FORM_ERR:
+		cf->data[2] |= CAN_ERR_PROT_FORM;
+		priv->can.can_stats.bus_error++;
+		stats->rx_errors++;
+		break;
+	case PCH_ACK_ERR:
+		cf->can_id |= CAN_ERR_ACK;
+		priv->can.can_stats.bus_error++;
+		stats->rx_errors++;
+		break;
+	case PCH_BIT1_ERR:
+	case PCH_BIT0_ERR:
+		cf->data[2] |= CAN_ERR_PROT_BIT;
+		priv->can.can_stats.bus_error++;
+		stats->rx_errors++;
+		break;
+	case PCH_CRC_ERR:
+		cf->data[2] |= CAN_ERR_PROT_LOC_CRC_SEQ |
+			       CAN_ERR_PROT_LOC_CRC_DEL;
+		priv->can.can_stats.bus_error++;
+		stats->rx_errors++;
+		break;
+	case PCH_LEC_ALL: /* Written by CPU. No error status */
+		break;
 	}
 
+	cf->data[6] = ioread32(&priv->regs->errc) & PCH_TEC;
+	cf->data[7] = (ioread32(&priv->regs->errc) & PCH_REC) >> 8;
+
 	priv->can.state = state;
-	netif_rx(skb);
+	netif_receive_skb(skb);
 
 	stats->rx_packets++;
 	stats->rx_bytes += cf->can_dlc;
@@ -775,199 +589,214 @@ static irqreturn_t pch_can_interrupt(int irq, void *dev_id)
 	struct pch_can_priv *priv = netdev_priv(ndev);
 
 	pch_can_set_int_enables(priv, PCH_CAN_NONE);
-
 	napi_schedule(&priv->napi);
 
 	return IRQ_HANDLED;
 }
 
-static int pch_can_rx_normal(struct net_device *ndev, u32 int_stat)
+static void pch_fifo_thresh(struct pch_can_priv *priv, int obj_id)
+{
+	if (obj_id < PCH_FIFO_THRESH) {
+		iowrite32(PCH_CMASK_RDWR | PCH_CMASK_CTRL |
+			  PCH_CMASK_ARB, &priv->regs->ifregs[0].cmask);
+
+		/* Clearing the Dir bit. */
+		pch_can_bit_clear(&priv->regs->ifregs[0].id2, PCH_ID2_DIR);
+
+		/* Clearing NewDat & IntPnd */
+		pch_can_bit_clear(&priv->regs->ifregs[0].mcont,
+				  PCH_IF_MCONT_INTPND);
+		pch_can_rw_msg_obj(&priv->regs->ifregs[0].creq, obj_id);
+	} else if (obj_id > PCH_FIFO_THRESH) {
+		pch_can_int_clr(priv, obj_id);
+	} else if (obj_id == PCH_FIFO_THRESH) {
+		int cnt;
+		for (cnt = 0; cnt < PCH_FIFO_THRESH; cnt++)
+			pch_can_int_clr(priv, cnt+1);
+	}
+}
+
+static int pch_can_rx_msg_lost(struct net_device *ndev, int obj_id)
+{
+	struct pch_can_priv *priv = netdev_priv(ndev);
+	struct net_device_stats *stats = &(priv->ndev->stats);
+	struct sk_buff *skb;
+	struct can_frame *cf;
+
+	netdev_dbg(priv->ndev, "Msg Obj is overwritten.\n");
+	pch_can_bit_clear(&priv->regs->ifregs[0].mcont,
+			  PCH_IF_MCONT_MSGLOST);
+	iowrite32(PCH_CMASK_RDWR | PCH_CMASK_CTRL,
+		  &priv->regs->ifregs[0].cmask);
+	pch_can_rw_msg_obj(&priv->regs->ifregs[0].creq, obj_id);
+
+	skb = alloc_can_err_skb(ndev, &cf);
+	if (!skb)
+		return -ENOMEM;
+
+	cf->can_id |= CAN_ERR_CRTL;
+	cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
+	stats->rx_over_errors++;
+	stats->rx_errors++;
+
+	netif_receive_skb(skb);
+
+	return 0;
+}
+
+static int pch_can_rx_normal(struct net_device *ndev, u32 obj_num, int quota)
 {
 	u32 reg;
 	canid_t id;
 	u32 ide;
 	u32 rtr;
-	int i, j, k;
 	int rcv_pkts = 0;
+	int rtn;
+	int next_flag = 0;
 	struct sk_buff *skb;
 	struct can_frame *cf;
 	struct pch_can_priv *priv = netdev_priv(ndev);
 	struct net_device_stats *stats = &(priv->ndev->stats);
+	u8 *can_data;
+	int i;
 
-	/* Reading the messsage object from the Message RAM */
-	iowrite32(CAN_CMASK_RX_TX_GET, &priv->regs->if1_cmask);
-	pch_can_check_if_busy(&priv->regs->if1_creq, int_stat);
+	do {
+		/* Reading the messsage object from the Message RAM */
+		iowrite32(PCH_CMASK_RX_TX_GET, &priv->regs->ifregs[0].cmask);
+		pch_can_rw_msg_obj(&priv->regs->ifregs[0].creq, obj_num);
 
-	/* Reading the MCONT register. */
-	reg = ioread32(&priv->regs->if1_mcont);
-	reg &= 0xffff;
+		/* Reading the MCONT register. */
+		reg = ioread32(&priv->regs->ifregs[0].mcont);
+
+		if (reg & PCH_IF_MCONT_EOB)
+			break;
 
-	for (k = int_stat; !(reg & CAN_IF_MCONT_EOB); k++) {
 		/* If MsgLost bit set. */
-		if (reg & CAN_IF_MCONT_MSGLOST) {
-			dev_err(&priv->ndev->dev, "Msg Obj is overwritten.\n");
-			pch_can_bit_clear(&priv->regs->if1_mcont,
-					  CAN_IF_MCONT_MSGLOST);
-			iowrite32(CAN_CMASK_RDWR | CAN_CMASK_CTRL,
-				  &priv->regs->if1_cmask);
-			pch_can_check_if_busy(&priv->regs->if1_creq, k);
-
-			skb = alloc_can_err_skb(ndev, &cf);
+		if (reg & PCH_IF_MCONT_MSGLOST) {
+			rtn = pch_can_rx_msg_lost(ndev, obj_num);
+			if (!rtn)
+				return rtn;
+			rcv_pkts++;
+			quota--;
+			next_flag = 1;
+		} else if (!(reg & PCH_IF_MCONT_NEWDAT))
+			next_flag = 1;
+
+		if (!next_flag) {
+			skb = alloc_can_skb(priv->ndev, &cf);
 			if (!skb)
 				return -ENOMEM;
 
-			priv->can.can_stats.error_passive++;
-			priv->can.state = CAN_STATE_ERROR_PASSIVE;
-			cf->can_id |= CAN_ERR_CRTL;
-			cf->data[1] |= CAN_ERR_CRTL_RX_OVERFLOW;
-			cf->data[2] |= CAN_ERR_PROT_OVERLOAD;
-			stats->rx_packets++;
-			stats->rx_bytes += cf->can_dlc;
+			/* Get Received data */
+			ide = ((ioread32(&priv->regs->ifregs[0].id2)) &
+					 PCH_ID2_XTD);
+			if (ide) {
+				id = (ioread32(&priv->regs->ifregs[0].id1) &
+					       0xffff);
+				id |= (((ioread32(&priv->regs->ifregs[0].id2)) &
+						  0x1fff) << 16);
+				cf->can_id = id | CAN_EFF_FLAG;
+			} else {
+				id = (((ioread32(&priv->regs->ifregs[0].id2)) &
+						(CAN_SFF_MASK << 2)) >> 2);
+				cf->can_id = id;
+			}
+
+			rtr = ioread32(&priv->regs->ifregs[0].id2) &
+					PCH_ID2_DIR;
+
+			if (rtr)
+				cf->can_id |= CAN_RTR_FLAG;
+
+			cf->can_dlc = get_can_dlc((ioread32(&priv->regs->
+						   ifregs[0].mcont)) & 0xF);
+
+			can_data = (u8 *)&priv->regs->ifregs[0].data[0];
+			for (i = 0; i < cf->can_dlc; i += 2, can_data += 4) {
+				cf->data[i] = ioread8(can_data);
+				cf->data[i+1] = ioread8(can_data + 1);
+			}
 
 			netif_receive_skb(skb);
 			rcv_pkts++;
-			goto RX_NEXT;
-		}
-		if (!(reg & CAN_IF_MCONT_NEWDAT))
-			goto RX_NEXT;
-
-		skb = alloc_can_skb(priv->ndev, &cf);
-		if (!skb)
-			return -ENOMEM;
-
-		/* Get Received data */
-		ide = ((ioread32(&priv->regs->if1_id2)) & CAN_ID2_XTD) >> 14;
-		if (ide) {
-			id = (ioread32(&priv->regs->if1_id1) & 0xffff);
-			id |= (((ioread32(&priv->regs->if1_id2)) &
-					    0x1fff) << 16);
-			cf->can_id = (id & CAN_EFF_MASK) | CAN_EFF_FLAG;
-		} else {
-			id = (((ioread32(&priv->regs->if1_id2)) &
-					  (CAN_SFF_MASK << 2)) >> 2);
-			cf->can_id = (id & CAN_SFF_MASK);
-		}
+			stats->rx_packets++;
+			quota--;
+			stats->rx_bytes += cf->can_dlc;
 
-		rtr = (ioread32(&priv->regs->if1_id2) &  CAN_ID2_DIR);
-		if (rtr) {
-			cf->can_dlc = 0;
-			cf->can_id |= CAN_RTR_FLAG;
-		} else {
-			cf->can_dlc = ((ioread32(&priv->regs->if1_mcont)) &
-						   0x0f);
+			pch_fifo_thresh(priv, obj_num);
 		}
+		obj_num++;
+		next_flag = 0;
+	} while (quota > 0);
 
-		for (i = 0, j = 0; i < cf->can_dlc; j++) {
-			reg = ioread32(&priv->regs->if1_dataa1 + j*4);
-			cf->data[i++] = cpu_to_le32(reg & 0xff);
-			if (i == cf->can_dlc)
-				break;
-			cf->data[i++] = cpu_to_le32((reg >> 8) & 0xff);
-		}
+	return rcv_pkts;
+}
 
-		netif_receive_skb(skb);
-		rcv_pkts++;
-		stats->rx_packets++;
-		stats->rx_bytes += cf->can_dlc;
-
-		if (k < PCH_FIFO_THRESH) {
-			iowrite32(CAN_CMASK_RDWR | CAN_CMASK_CTRL |
-				  CAN_CMASK_ARB, &priv->regs->if1_cmask);
-
-			/* Clearing the Dir bit. */
-			pch_can_bit_clear(&priv->regs->if1_id2, CAN_ID2_DIR);
-
-			/* Clearing NewDat & IntPnd */
-			pch_can_bit_clear(&priv->regs->if1_mcont,
-					  CAN_IF_MCONT_INTPND);
-			pch_can_check_if_busy(&priv->regs->if1_creq, k);
-		} else if (k > PCH_FIFO_THRESH) {
-			pch_can_int_clr(priv, k);
-		} else if (k == PCH_FIFO_THRESH) {
-			int cnt;
-			for (cnt = 0; cnt < PCH_FIFO_THRESH; cnt++)
-				pch_can_int_clr(priv, cnt+1);
-		}
-RX_NEXT:
-		/* Reading the messsage object from the Message RAM */
-		iowrite32(CAN_CMASK_RX_TX_GET, &priv->regs->if1_cmask);
-		pch_can_check_if_busy(&priv->regs->if1_creq, k + 1);
-		reg = ioread32(&priv->regs->if1_mcont);
-	}
+static void pch_can_tx_complete(struct net_device *ndev, u32 int_stat)
+{
+	struct pch_can_priv *priv = netdev_priv(ndev);
+	struct net_device_stats *stats = &(priv->ndev->stats);
+	u32 dlc;
 
-	return rcv_pkts;
+	can_get_echo_skb(ndev, int_stat - PCH_RX_OBJ_END - 1);
+	iowrite32(PCH_CMASK_RX_TX_GET | PCH_CMASK_CLRINTPND,
+		  &priv->regs->ifregs[1].cmask);
+	dlc = get_can_dlc(ioread32(&priv->regs->ifregs[1].mcont) &
+			  PCH_IF_MCONT_DLC);
+	pch_can_rw_msg_obj(&priv->regs->ifregs[1].creq, int_stat);
+	stats->tx_bytes += dlc;
+	stats->tx_packets++;
+	if ((int_stat == PCH_TX_OBJ_END) && (priv->netif_stop == 1)) {
+		netif_wake_queue(ndev);
+		priv->netif_stop = 0;
+	}
 }
+
 static int pch_can_rx_poll(struct napi_struct *napi, int quota)
 {
 	struct net_device *ndev = napi->dev;
 	struct pch_can_priv *priv = netdev_priv(ndev);
-	struct net_device_stats *stats = &(priv->ndev->stats);
-	u32 dlc;
 	u32 int_stat;
 	int rcv_pkts = 0;
 	u32 reg_stat;
-	unsigned long flags;
 
 	int_stat = pch_can_int_pending(priv);
 	if (!int_stat)
-		return 0;
+		goto end;
 
-INT_STAT:
-	if (int_stat == CAN_STATUS_INT) {
+	if ((int_stat == PCH_STATUS_INT) && (quota > 0)) {
 		reg_stat = ioread32(&priv->regs->stat);
 		if (reg_stat & (PCH_BUS_OFF | PCH_LEC_ALL)) {
-			if ((reg_stat & PCH_LEC_ALL) != PCH_LEC_ALL)
+			if ((reg_stat & PCH_LEC_ALL) != PCH_LEC_ALL) {
 				pch_can_error(ndev, reg_stat);
+				quota--;
+			}
 		}
 
-		if (reg_stat & PCH_TX_OK) {
-			spin_lock_irqsave(&priv->msgif_reg_lock, flags);
-			iowrite32(CAN_CMASK_RX_TX_GET, &priv->regs->if2_cmask);
-			pch_can_check_if_busy(&priv->regs->if2_creq,
-					       ioread32(&priv->regs->intr));
-			spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
+		if (reg_stat & PCH_TX_OK)
 			pch_can_bit_clear(&priv->regs->stat, PCH_TX_OK);
-		}
 
 		if (reg_stat & PCH_RX_OK)
 			pch_can_bit_clear(&priv->regs->stat, PCH_RX_OK);
 
 		int_stat = pch_can_int_pending(priv);
-		if (int_stat == CAN_STATUS_INT)
-			goto INT_STAT;
 	}
 
-MSG_OBJ:
-	if ((int_stat >= 1) && (int_stat <= PCH_RX_OBJ_NUM)) {
-		spin_lock_irqsave(&priv->msgif_reg_lock, flags);
-		rcv_pkts = pch_can_rx_normal(ndev, int_stat);
-		spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
-		if (rcv_pkts < 0)
-			return 0;
-	} else if ((int_stat > PCH_RX_OBJ_NUM) && (int_stat <= PCH_OBJ_NUM)) {
-		if (priv->msg_obj[int_stat - 1] == MSG_OBJ_TX) {
-			/* Handle transmission interrupt */
-			can_get_echo_skb(ndev, int_stat - PCH_RX_OBJ_NUM - 1);
-			spin_lock_irqsave(&priv->msgif_reg_lock, flags);
-			iowrite32(CAN_CMASK_RX_TX_GET | CAN_CMASK_CLRINTPND,
-				  &priv->regs->if2_cmask);
-			dlc = ioread32(&priv->regs->if2_mcont) &
-				       CAN_IF_MCONT_DLC;
-			pch_can_check_if_busy(&priv->regs->if2_creq, int_stat);
-			spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
-			if (dlc > 8)
-				dlc = 8;
-			stats->tx_bytes += dlc;
-			stats->tx_packets++;
-		}
+	if (quota == 0)
+		goto end;
+
+	if ((int_stat >= PCH_RX_OBJ_START) && (int_stat <= PCH_RX_OBJ_END)) {
+		rcv_pkts += pch_can_rx_normal(ndev, int_stat, quota);
+		quota -= rcv_pkts;
+		if (quota < 0)
+			goto end;
+	} else if ((int_stat >= PCH_TX_OBJ_START) &&
+		   (int_stat <= PCH_TX_OBJ_END)) {
+		/* Handle transmission interrupt */
+		pch_can_tx_complete(ndev, int_stat);
 	}
 
-	int_stat = pch_can_int_pending(priv);
-	if (int_stat == CAN_STATUS_INT)
-		goto INT_STAT;
-	else if (int_stat >= 1 && int_stat <= 32)
-		goto MSG_OBJ;
-
+end:
 	napi_complete(napi);
 	pch_can_set_int_enables(priv, PCH_CAN_ALL);
 
@@ -980,20 +809,18 @@ static int pch_set_bittiming(struct net_device *ndev)
 	const struct can_bittiming *bt = &priv->can.bittiming;
 	u32 canbit;
 	u32 bepe;
-	u32 brp;
 
 	/* Setting the CCE bit for accessing the Can Timing register. */
-	pch_can_bit_set(&priv->regs->cont, CAN_CTRL_CCE);
-
-	brp = (bt->tq) / (1000000000/PCH_CAN_CLK) - 1;
-	canbit = brp & MSK_BITT_BRP;
-	canbit |= (bt->sjw - 1) << BIT_BITT_SJW;
-	canbit |= (bt->phase_seg1 + bt->prop_seg - 1) << BIT_BITT_TSEG1;
-	canbit |= (bt->phase_seg2 - 1) << BIT_BITT_TSEG2;
-	bepe = (brp & MSK_BRPE_BRPE) >> BIT_BRPE_BRPE;
+	pch_can_bit_set(&priv->regs->cont, PCH_CTRL_CCE);
+
+	canbit = (bt->brp - 1) & PCH_MSK_BITT_BRP;
+	canbit |= (bt->sjw - 1) << PCH_BIT_SJW_SHIFT;
+	canbit |= (bt->phase_seg1 + bt->prop_seg - 1) << PCH_BIT_TSEG1_SHIFT;
+	canbit |= (bt->phase_seg2 - 1) << PCH_BIT_TSEG2_SHIFT;
+	bepe = ((bt->brp - 1) & PCH_MSK_BRPE_BRPE) >> PCH_BIT_BRPE_BRPE_SHIFT;
 	iowrite32(canbit, &priv->regs->bitt);
 	iowrite32(bepe, &priv->regs->brpe);
-	pch_can_bit_clear(&priv->regs->cont, CAN_CTRL_CCE);
+	pch_can_bit_clear(&priv->regs->cont, PCH_CTRL_CCE);
 
 	return 0;
 }
@@ -1008,8 +835,8 @@ static void pch_can_start(struct net_device *ndev)
 	pch_set_bittiming(ndev);
 	pch_can_set_optmode(priv);
 
-	pch_can_tx_enable_all(priv);
-	pch_can_rx_enable_all(priv);
+	pch_can_set_tx_all(priv, 1);
+	pch_can_set_rx_all(priv, 1);
 
 	/* Setting the CAN to run mode. */
 	pch_can_set_run_mode(priv, PCH_CAN_RUN);
@@ -1041,27 +868,18 @@ static int pch_can_open(struct net_device *ndev)
 	struct pch_can_priv *priv = netdev_priv(ndev);
 	int retval;
 
-	retval = pci_enable_msi(priv->dev);
-	if (retval) {
-		dev_info(&ndev->dev, "PCH CAN opened without MSI\n");
-		priv->use_msi = 0;
-	} else {
-		dev_info(&ndev->dev, "PCH CAN opened with MSI\n");
-		priv->use_msi = 1;
-	}
-
-	/* Regsitering the interrupt. */
+	/* Regstering the interrupt. */
 	retval = request_irq(priv->dev->irq, pch_can_interrupt, IRQF_SHARED,
 			     ndev->name, ndev);
 	if (retval) {
-		dev_err(&ndev->dev, "request_irq failed.\n");
+		netdev_err(ndev, "request_irq failed.\n");
 		goto req_irq_err;
 	}
 
 	/* Open common can device */
 	retval = open_candev(ndev);
 	if (retval) {
-		dev_err(ndev->dev.parent, "open_candev() failed %d\n", retval);
+		netdev_err(ndev, "open_candev() failed %d\n", retval);
 		goto err_open_candev;
 	}
 
@@ -1075,9 +893,6 @@ static int pch_can_open(struct net_device *ndev)
 err_open_candev:
 	free_irq(priv->dev->irq, ndev);
 req_irq_err:
-	if (priv->use_msi)
-		pci_disable_msi(priv->dev);
-
 	pch_can_release(priv);
 
 	return retval;
@@ -1091,102 +906,70 @@ static int pch_close(struct net_device *ndev)
 	napi_disable(&priv->napi);
 	pch_can_release(priv);
 	free_irq(priv->dev->irq, ndev);
-	if (priv->use_msi)
-		pci_disable_msi(priv->dev);
 	close_candev(ndev);
 	priv->can.state = CAN_STATE_STOPPED;
 	return 0;
 }
 
-static int pch_get_msg_obj_sts(struct net_device *ndev, u32 obj_id)
-{
-	u32 buffer_status = 0;
-	struct pch_can_priv *priv = netdev_priv(ndev);
-
-	/* Getting the message object status. */
-	buffer_status = (u32) pch_can_get_buffer_status(priv);
-
-	return buffer_status & obj_id;
-}
-
-
 static netdev_tx_t pch_xmit(struct sk_buff *skb, struct net_device *ndev)
 {
-	int i, j;
-	unsigned long flags;
 	struct pch_can_priv *priv = netdev_priv(ndev);
 	struct can_frame *cf = (struct can_frame *)skb->data;
-	int tx_buffer_avail = 0;
+	int tx_obj_no = 0;
+	int i;
 
 	if (can_dropped_invalid_skb(ndev, skb))
 		return NETDEV_TX_OK;
 
-	if (priv->tx_obj == (PCH_OBJ_NUM + 1)) { /* Point tail Obj */
-		while (pch_get_msg_obj_sts(ndev, (((1 << PCH_TX_OBJ_NUM)-1) <<
-					   PCH_RX_OBJ_NUM)))
-			udelay(500);
-
-		priv->tx_obj = PCH_RX_OBJ_NUM + 1; /* Point head of Tx Obj ID */
-		tx_buffer_avail = priv->tx_obj; /* Point Tail of Tx Obj */
+	if (priv->tx_obj == PCH_TX_OBJ_END) {
+		if (ioread32(&priv->regs->treq2) & 0xfc00) {
+			netif_stop_queue(ndev);
+			priv->netif_stop = 1;
+		}
+		tx_obj_no = priv->tx_obj;
+		priv->tx_obj = PCH_TX_OBJ_START;
 	} else {
-		tx_buffer_avail = priv->tx_obj;
+		tx_obj_no = priv->tx_obj;
+		priv->tx_obj++;
 	}
-	priv->tx_obj++;
-
-	/* Attaining the lock. */
-	spin_lock_irqsave(&priv->msgif_reg_lock, flags);
-
-	/* Reading the Msg Obj from the Msg RAM to the Interface register. */
-	iowrite32(CAN_CMASK_RX_TX_GET, &priv->regs->if2_cmask);
-	pch_can_check_if_busy(&priv->regs->if2_creq, tx_buffer_avail);
 
-	/* Setting the CMASK register. */
-	pch_can_bit_set(&priv->regs->if2_cmask, CAN_CMASK_ALL);
+	/* Setting the CMASK register to set value */
+	iowrite32(PCH_CMASK_RX_TX_SET, &priv->regs->ifregs[1].cmask);
 
 	/* If ID extended is set. */
-	pch_can_bit_clear(&priv->regs->if2_id1, 0xffff);
-	pch_can_bit_clear(&priv->regs->if2_id2, 0x1fff | CAN_ID2_XTD);
 	if (cf->can_id & CAN_EFF_FLAG) {
-		pch_can_bit_set(&priv->regs->if2_id1, cf->can_id & 0xffff);
-		pch_can_bit_set(&priv->regs->if2_id2,
-				((cf->can_id >> 16) & 0x1fff) | CAN_ID2_XTD);
+		iowrite32(cf->can_id & 0xffff, &priv->regs->ifregs[1].id1);
+		iowrite32(((cf->can_id >> 16) & 0x1fff) | PCH_ID2_XTD,
+			    &priv->regs->ifregs[1].id2);
 	} else {
-		pch_can_bit_set(&priv->regs->if2_id1, 0);
-		pch_can_bit_set(&priv->regs->if2_id2,
-				(cf->can_id & CAN_SFF_MASK) << 2);
+		iowrite32(0, &priv->regs->ifregs[1].id1);
+		iowrite32((cf->can_id & CAN_SFF_MASK) << 2,
+			   &priv->regs->ifregs[1].id2);
 	}
 
+	pch_can_bit_set(&priv->regs->ifregs[1].id2, PCH_ID_MSGVAL);
+
+	/* If remote frame has to be transmitted.. */
+	if (!(cf->can_id & CAN_RTR_FLAG))
+		pch_can_bit_set(&priv->regs->ifregs[1].id2, PCH_ID2_DIR);
+
 	/* If remote frame has to be transmitted.. */
 	if (cf->can_id & CAN_RTR_FLAG)
-		pch_can_bit_clear(&priv->regs->if2_id2, CAN_ID2_DIR);
+		pch_can_bit_clear(&priv->regs->ifregs[1].id2, PCH_ID2_DIR);
 
-	for (i = 0, j = 0; i < cf->can_dlc; j++) {
-		iowrite32(le32_to_cpu(cf->data[i++]),
-			 (&priv->regs->if2_dataa1) + j*4);
-		if (i == cf->can_dlc)
-			break;
-		iowrite32(le32_to_cpu(cf->data[i++] << 8),
-			 (&priv->regs->if2_dataa1) + j*4);
+	/* Copy data to register */
+	for (i = 0; i < cf->can_dlc; i += 2) {
+		iowrite16(cf->data[i] | (cf->data[i+1] << 8),
+			  &priv->regs->ifregs[1].data[i/2]);
 	}
 
-	can_put_echo_skb(skb, ndev, tx_buffer_avail - PCH_RX_OBJ_NUM - 1);
+	can_put_echo_skb(skb, ndev, tx_obj_no - PCH_RX_OBJ_END - 1);
 
-	/* Updating the size of the data. */
-	pch_can_bit_clear(&priv->regs->if2_mcont, 0x0f);
-	pch_can_bit_set(&priv->regs->if2_mcont, cf->can_dlc);
+	/* Set the size of the data. Update if2_mcont*/
+	iowrite32(cf->can_dlc | PCH_IF_MCONT_NEWDAT | PCH_IF_MCONT_TXRQXT |
+		  PCH_IF_MCONT_TXIE, &priv->regs->ifregs[1].mcont);
 
-	/* Clearing IntPend, NewDat & TxRqst */
-	pch_can_bit_clear(&priv->regs->if2_mcont,
-			  CAN_IF_MCONT_NEWDAT | CAN_IF_MCONT_INTPND |
-			  CAN_IF_MCONT_TXRQXT);
-
-	/* Setting NewDat, TxRqst bits */
-	pch_can_bit_set(&priv->regs->if2_mcont,
-			CAN_IF_MCONT_NEWDAT | CAN_IF_MCONT_TXRQXT);
-
-	pch_can_check_if_busy(&priv->regs->if2_creq, tx_buffer_avail);
-
-	spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
+	pch_can_rw_msg_obj(&priv->regs->ifregs[1].creq, tx_obj_no);
 
 	return NETDEV_TX_OK;
 }
@@ -1203,21 +986,90 @@ static void __devexit pch_can_remove(struct pci_dev *pdev)
 	struct pch_can_priv *priv = netdev_priv(ndev);
 
 	unregister_candev(priv->ndev);
-	free_candev(priv->ndev);
 	pci_iounmap(pdev, priv->regs);
+	if (priv->use_msi)
+		pci_disable_msi(priv->dev);
 	pci_release_regions(pdev);
 	pci_disable_device(pdev);
 	pci_set_drvdata(pdev, NULL);
 	pch_can_reset(priv);
+	free_candev(priv->ndev);
 }
 
 #ifdef CONFIG_PM
+static void pch_can_set_int_custom(struct pch_can_priv *priv)
+{
+	/* Clearing the IE, SIE and EIE bits of Can control register. */
+	pch_can_bit_clear(&priv->regs->cont, PCH_CTRL_IE_SIE_EIE);
+
+	/* Appropriately setting them. */
+	pch_can_bit_set(&priv->regs->cont,
+			((priv->int_enables & PCH_MSK_CTRL_IE_SIE_EIE) << 1));
+}
+
+/* This function retrieves interrupt enabled for the CAN device. */
+static u32 pch_can_get_int_enables(struct pch_can_priv *priv)
+{
+	/* Obtaining the status of IE, SIE and EIE interrupt bits. */
+	return (ioread32(&priv->regs->cont) & PCH_CTRL_IE_SIE_EIE) >> 1;
+}
+
+static u32 pch_can_get_rxtx_ir(struct pch_can_priv *priv, u32 buff_num, u32 dir)
+{
+	u32 ie, enable;
+
+	if (dir)
+		ie = PCH_IF_MCONT_RXIE;
+	else
+		ie = PCH_IF_MCONT_TXIE;
+
+	iowrite32(PCH_CMASK_RX_TX_GET, &priv->regs->ifregs[dir].cmask);
+	pch_can_rw_msg_obj(&priv->regs->ifregs[dir].creq, buff_num);
+
+	if (((ioread32(&priv->regs->ifregs[dir].id2)) & PCH_ID_MSGVAL) &&
+			((ioread32(&priv->regs->ifregs[dir].mcont)) & ie))
+		enable = 1;
+	else
+		enable = 0;
+	return enable;
+}
+
+static void pch_can_set_rx_buffer_link(struct pch_can_priv *priv,
+				       u32 buffer_num, u32 set)
+{
+	iowrite32(PCH_CMASK_RX_TX_GET, &priv->regs->ifregs[0].cmask);
+	pch_can_rw_msg_obj(&priv->regs->ifregs[0].creq, buffer_num);
+	iowrite32(PCH_CMASK_RDWR | PCH_CMASK_CTRL,
+		  &priv->regs->ifregs[0].cmask);
+	if (set)
+		pch_can_bit_clear(&priv->regs->ifregs[0].mcont,
+				  PCH_IF_MCONT_EOB);
+	else
+		pch_can_bit_set(&priv->regs->ifregs[0].mcont, PCH_IF_MCONT_EOB);
+
+	pch_can_rw_msg_obj(&priv->regs->ifregs[0].creq, buffer_num);
+}
+
+static u32 pch_can_get_rx_buffer_link(struct pch_can_priv *priv, u32 buffer_num)
+{
+	u32 link;
+
+	iowrite32(PCH_CMASK_RX_TX_GET, &priv->regs->ifregs[0].cmask);
+	pch_can_rw_msg_obj(&priv->regs->ifregs[0].creq, buffer_num);
+
+	if (ioread32(&priv->regs->ifregs[0].mcont) & PCH_IF_MCONT_EOB)
+		link = 0;
+	else
+		link = 1;
+	return link;
+}
+
 static int pch_can_suspend(struct pci_dev *pdev, pm_message_t state)
 {
-	int i;			/* Counter variable. */
-	int retval;		/* Return value. */
+	int i;
+	int retval;
 	u32 buf_stat;	/* Variable for reading the transmit buffer status. */
-	u32 counter = 0xFFFFFF;
+	u32 counter = PCH_COUNTER_LIMIT;
 
 	struct net_device *dev = pci_get_drvdata(pdev);
 	struct pch_can_priv *priv = netdev_priv(dev);
@@ -1226,7 +1078,7 @@ static int pch_can_suspend(struct pci_dev *pdev, pm_message_t state)
 	pch_can_set_run_mode(priv, PCH_CAN_STOP);
 
 	/* Indicate that we are aboutto/in suspend */
-	priv->can.state = CAN_STATE_SLEEPING;
+	priv->can.state = CAN_STATE_STOPPED;
 
 	/* Waiting for all transmission to complete. */
 	while (counter) {
@@ -1240,31 +1092,24 @@ static int pch_can_suspend(struct pci_dev *pdev, pm_message_t state)
 		dev_err(&pdev->dev, "%s -> Transmission time out.\n", __func__);
 
 	/* Save interrupt configuration and then disable them */
-	pch_can_get_int_enables(priv, &(priv->int_enables));
+	priv->int_enables = pch_can_get_int_enables(priv);
 	pch_can_set_int_enables(priv, PCH_CAN_DISABLE);
 
 	/* Save Tx buffer enable state */
-	for (i = 0; i < PCH_OBJ_NUM; i++) {
-		if (priv->msg_obj[i] == MSG_OBJ_TX)
-			pch_can_get_tx_enable(priv, i + 1,
-					      &(priv->tx_enable[i]));
-	}
+	for (i = PCH_TX_OBJ_START; i <= PCH_TX_OBJ_END; i++)
+		priv->tx_enable[i] = pch_can_get_rxtx_ir(priv, i, PCH_TX_IFREG);
 
 	/* Disable all Transmit buffers */
-	pch_can_tx_disable_all(priv);
+	pch_can_set_tx_all(priv, 0);
 
 	/* Save Rx buffer enable state */
-	for (i = 0; i < PCH_OBJ_NUM; i++) {
-		if (priv->msg_obj[i] == MSG_OBJ_RX) {
-			pch_can_get_rx_enable(priv, i + 1,
-						&(priv->rx_enable[i]));
-			pch_can_get_rx_buffer_link(priv, i + 1,
-						&(priv->rx_link[i]));
-		}
+	for (i = PCH_RX_OBJ_START; i <= PCH_RX_OBJ_END; i++) {
+		priv->rx_enable[i] = pch_can_get_rxtx_ir(priv, i, PCH_RX_IFREG);
+		priv->rx_link[i] = pch_can_get_rx_buffer_link(priv, i);
 	}
 
 	/* Disable all Receive buffers */
-	pch_can_rx_disable_all(priv);
+	pch_can_set_rx_all(priv, 0);
 	retval = pci_save_state(pdev);
 	if (retval) {
 		dev_err(&pdev->dev, "pci_save_state failed.\n");
@@ -1279,8 +1124,8 @@ static int pch_can_suspend(struct pci_dev *pdev, pm_message_t state)
 
 static int pch_can_resume(struct pci_dev *pdev)
 {
-	int i;			/* Counter variable. */
-	int retval;		/* Return variable. */
+	int i;
+	int retval;
 	struct net_device *dev = pci_get_drvdata(pdev);
 	struct pch_can_priv *priv = netdev_priv(dev);
 
@@ -1312,23 +1157,16 @@ static int pch_can_resume(struct pci_dev *pdev)
 	pch_can_set_optmode(priv);
 
 	/* Enabling the transmit buffer. */
-	for (i = 0; i < PCH_OBJ_NUM; i++) {
-		if (priv->msg_obj[i] == MSG_OBJ_TX) {
-			pch_can_set_tx_enable(priv, i + 1,
-					      priv->tx_enable[i]);
-		}
-	}
+	for (i = PCH_RX_OBJ_START; i <= PCH_RX_OBJ_END; i++)
+		pch_can_set_rxtx(priv, i, priv->tx_enable[i], PCH_TX_IFREG);
 
 	/* Configuring the receive buffer and enabling them. */
-	for (i = 0; i < PCH_OBJ_NUM; i++) {
-		if (priv->msg_obj[i] == MSG_OBJ_RX) {
-			/* Restore buffer link */
-			pch_can_set_rx_buffer_link(priv, i + 1,
-						   priv->rx_link[i]);
-
-			/* Restore buffer enables */
-			pch_can_set_rx_enable(priv, i + 1, priv->rx_enable[i]);
-		}
+	for (i = PCH_TX_OBJ_START; i <= PCH_TX_OBJ_END; i++) {
+		/* Restore buffer link */
+		pch_can_set_rx_buffer_link(priv, i, priv->rx_link[i]);
+
+		/* Restore buffer enables */
+		pch_can_set_rxtx(priv, i, priv->rx_enable[i], PCH_RX_IFREG);
 	}
 
 	/* Enable CAN Interrupts */
@@ -1349,8 +1187,8 @@ static int pch_can_get_berr_counter(const struct net_device *dev,
 {
 	struct pch_can_priv *priv = netdev_priv(dev);
 
-	bec->txerr = ioread32(&priv->regs->errc) & CAN_TEC;
-	bec->rxerr = (ioread32(&priv->regs->errc) & CAN_REC) >> 8;
+	bec->txerr = ioread32(&priv->regs->errc) & PCH_TEC;
+	bec->rxerr = (ioread32(&priv->regs->errc) & PCH_REC) >> 8;
 
 	return 0;
 }
@@ -1361,7 +1199,6 @@ static int __devinit pch_can_probe(struct pci_dev *pdev,
 	struct net_device *ndev;
 	struct pch_can_priv *priv;
 	int rc;
-	int index;
 	void __iomem *addr;
 
 	rc = pci_enable_device(pdev);
@@ -1383,7 +1220,8 @@ static int __devinit pch_can_probe(struct pci_dev *pdev,
 		goto probe_exit_ipmap;
 	}
 
-	ndev = alloc_candev(sizeof(struct pch_can_priv), PCH_TX_OBJ_NUM);
+	ndev = alloc_candev(sizeof(struct pch_can_priv),
+			    PCH_TX_OBJ_END - PCH_TX_OBJ_START + 1);
 	if (!ndev) {
 		rc = -ENOMEM;
 		dev_err(&pdev->dev, "Failed alloc_candev\n");
@@ -1399,7 +1237,7 @@ static int __devinit pch_can_probe(struct pci_dev *pdev,
 	priv->can.do_get_berr_counter = pch_can_get_berr_counter;
 	priv->can.ctrlmode_supported = CAN_CTRLMODE_LISTENONLY |
 				       CAN_CTRLMODE_LOOPBACK;
-	priv->tx_obj = PCH_RX_OBJ_NUM + 1; /* Point head of Tx Obj */
+	priv->tx_obj = PCH_TX_OBJ_START; /* Point head of Tx Obj */
 
 	ndev->irq = pdev->irq;
 	ndev->flags |= IFF_ECHO;
@@ -1407,15 +1245,18 @@ static int __devinit pch_can_probe(struct pci_dev *pdev,
 	pci_set_drvdata(pdev, ndev);
 	SET_NETDEV_DEV(ndev, &pdev->dev);
 	ndev->netdev_ops = &pch_can_netdev_ops;
-
 	priv->can.clock.freq = PCH_CAN_CLK; /* Hz */
-	for (index = 0; index < PCH_RX_OBJ_NUM;)
-		priv->msg_obj[index++] = MSG_OBJ_RX;
 
-	for (index = index;  index < PCH_OBJ_NUM;)
-		priv->msg_obj[index++] = MSG_OBJ_TX;
+	netif_napi_add(ndev, &priv->napi, pch_can_rx_poll, PCH_RX_OBJ_END);
 
-	netif_napi_add(ndev, &priv->napi, pch_can_rx_poll, PCH_RX_OBJ_NUM);
+	rc = pci_enable_msi(priv->dev);
+	if (rc) {
+		dev_info(&ndev->dev, "PCH CAN opened without MSI\n");
+		priv->use_msi = 0;
+	} else {
+		dev_info(&ndev->dev, "PCH CAN opened with MSI\n");
+		priv->use_msi = 1;
+	}
 
 	rc = register_candev(ndev);
 	if (rc) {
@@ -1426,7 +1267,8 @@ static int __devinit pch_can_probe(struct pci_dev *pdev,
 	return 0;
 
 probe_exit_reg_candev:
-	free_candev(ndev);
+	if (priv->use_msi)
+		pci_disable_msi(priv->dev);
 probe_exit_alloc_candev:
 	pci_iounmap(pdev, addr);
 probe_exit_ipmap:
@@ -1458,6 +1300,6 @@ static void __exit pch_can_pci_exit(void)
 }
 module_exit(pch_can_pci_exit);
 
-MODULE_DESCRIPTION("Controller Area Network Driver");
+MODULE_DESCRIPTION("Intel EG20T PCH CAN(Controller Area Network) Driver");
 MODULE_LICENSE("GPL v2");
 MODULE_VERSION("0.94");
-- 
1.6.0.6