can: c_can: Move overlay structure to array with offset as index

c_can uses overlay structure for accessing c_can module registers.
With this kind of implementation it is difficult to add one more ip
which is similar to c_can in functionality but different register
offsets.

This patch changes the overlay structure implementation to an array
with register offset as index. This way we can overcome the above
limitation.

Signed-off-by: AnilKumar Ch <anilkumar@ti.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

3 files changed, 154 insertions, 107 deletions

diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c
index 8dc84d66eea1..e2ce508c2753 100644
--- a/drivers/net/can/c_can/c_can.c
+++ b/drivers/net/can/c_can/c_can.c
@@ -41,6 +41,10 @@
 
 #include "c_can.h"
 
+/* Number of interface registers */
+#define IF_ENUM_REG_LEN		11
+#define C_CAN_IFACE(reg, iface)	(C_CAN_IF1_##reg + (iface) * IF_ENUM_REG_LEN)
+
 /* control register */
 #define CONTROL_TEST		BIT(7)
 #define CONTROL_CCE		BIT(6)
@@ -209,10 +213,10 @@ static inline int get_tx_echo_msg_obj(const struct c_can_priv *priv)
 			C_CAN_MSG_OBJ_TX_FIRST;
 }
 
-static u32 c_can_read_reg32(struct c_can_priv *priv, void *reg)
+static u32 c_can_read_reg32(struct c_can_priv *priv, enum reg index)
 {
-	u32 val = priv->read_reg(priv, reg);
-	val |= ((u32) priv->read_reg(priv, reg + 2)) << 16;
+	u32 val = priv->read_reg(priv, index);
+	val |= ((u32) priv->read_reg(priv, index + 1)) << 16;
 	return val;
 }
 
@@ -220,14 +224,14 @@ static void c_can_enable_all_interrupts(struct c_can_priv *priv,
 						int enable)
 {
 	unsigned int cntrl_save = priv->read_reg(priv,
-						&priv->regs->control);
+						C_CAN_CTRL_REG);
 
 	if (enable)
 		cntrl_save |= (CONTROL_SIE | CONTROL_EIE | CONTROL_IE);
 	else
 		cntrl_save &= ~(CONTROL_EIE | CONTROL_IE | CONTROL_SIE);
 
-	priv->write_reg(priv, &priv->regs->control, cntrl_save);
+	priv->write_reg(priv, C_CAN_CTRL_REG, cntrl_save);
 }
 
 static inline int c_can_msg_obj_is_busy(struct c_can_priv *priv, int iface)
@@ -235,7 +239,7 @@ static inline int c_can_msg_obj_is_busy(struct c_can_priv *priv, int iface)
 	int count = MIN_TIMEOUT_VALUE;
 
 	while (count && priv->read_reg(priv,
-				&priv->regs->ifregs[iface].com_req) &
+				C_CAN_IFACE(COMREQ_REG, iface)) &
 				IF_COMR_BUSY) {
 		count--;
 		udelay(1);
@@ -258,9 +262,9 @@ static inline void c_can_object_get(struct net_device *dev,
 	 * register and message RAM must be complete in 6 CAN-CLK
 	 * period.
 	 */
-	priv->write_reg(priv, &priv->regs->ifregs[iface].com_mask,
+	priv->write_reg(priv, C_CAN_IFACE(COMMSK_REG, iface),
 			IFX_WRITE_LOW_16BIT(mask));
-	priv->write_reg(priv, &priv->regs->ifregs[iface].com_req,
+	priv->write_reg(priv, C_CAN_IFACE(COMREQ_REG, iface),
 			IFX_WRITE_LOW_16BIT(objno));
 
 	if (c_can_msg_obj_is_busy(priv, iface))
@@ -278,9 +282,9 @@ static inline void c_can_object_put(struct net_device *dev,
 	 * register and message RAM must be complete in 6 CAN-CLK
 	 * period.
 	 */
-	priv->write_reg(priv, &priv->regs->ifregs[iface].com_mask,
+	priv->write_reg(priv, C_CAN_IFACE(COMMSK_REG, iface),
 			(IF_COMM_WR | IFX_WRITE_LOW_16BIT(mask)));
-	priv->write_reg(priv, &priv->regs->ifregs[iface].com_req,
+	priv->write_reg(priv, C_CAN_IFACE(COMREQ_REG, iface),
 			IFX_WRITE_LOW_16BIT(objno));
 
 	if (c_can_msg_obj_is_busy(priv, iface))
@@ -306,18 +310,18 @@ static void c_can_write_msg_object(struct net_device *dev,
 
 	flags |= IF_ARB_MSGVAL;
 
-	priv->write_reg(priv, &priv->regs->ifregs[iface].arb1,
+	priv->write_reg(priv, C_CAN_IFACE(ARB1_REG, iface),
 				IFX_WRITE_LOW_16BIT(id));
-	priv->write_reg(priv, &priv->regs->ifregs[iface].arb2, flags |
+	priv->write_reg(priv, C_CAN_IFACE(ARB2_REG, iface), flags |
 				IFX_WRITE_HIGH_16BIT(id));
 
 	for (i = 0; i < frame->can_dlc; i += 2) {
-		priv->write_reg(priv, &priv->regs->ifregs[iface].data[i / 2],
+		priv->write_reg(priv, C_CAN_IFACE(DATA1_REG, iface) + i / 2,
 				frame->data[i] | (frame->data[i + 1] << 8));
 	}
 
 	/* enable interrupt for this message object */
-	priv->write_reg(priv, &priv->regs->ifregs[iface].msg_cntrl,
+	priv->write_reg(priv, C_CAN_IFACE(MSGCTRL_REG, iface),
 			IF_MCONT_TXIE | IF_MCONT_TXRQST | IF_MCONT_EOB |
 			frame->can_dlc);
 	c_can_object_put(dev, iface, objno, IF_COMM_ALL);
@@ -329,7 +333,7 @@ static inline void c_can_mark_rx_msg_obj(struct net_device *dev,
 {
 	struct c_can_priv *priv = netdev_priv(dev);
 
-	priv->write_reg(priv, &priv->regs->ifregs[iface].msg_cntrl,
+	priv->write_reg(priv, C_CAN_IFACE(MSGCTRL_REG, iface),
 			ctrl_mask & ~(IF_MCONT_MSGLST | IF_MCONT_INTPND));
 	c_can_object_put(dev, iface, obj, IF_COMM_CONTROL);
 
@@ -343,7 +347,7 @@ static inline void c_can_activate_all_lower_rx_msg_obj(struct net_device *dev,
 	struct c_can_priv *priv = netdev_priv(dev);
 
 	for (i = C_CAN_MSG_OBJ_RX_FIRST; i <= C_CAN_MSG_RX_LOW_LAST; i++) {
-		priv->write_reg(priv, &priv->regs->ifregs[iface].msg_cntrl,
+		priv->write_reg(priv, C_CAN_IFACE(MSGCTRL_REG, iface),
 				ctrl_mask & ~(IF_MCONT_MSGLST |
 					IF_MCONT_INTPND | IF_MCONT_NEWDAT));
 		c_can_object_put(dev, iface, i, IF_COMM_CONTROL);
@@ -356,7 +360,7 @@ static inline void c_can_activate_rx_msg_obj(struct net_device *dev,
 {
 	struct c_can_priv *priv = netdev_priv(dev);
 
-	priv->write_reg(priv, &priv->regs->ifregs[iface].msg_cntrl,
+	priv->write_reg(priv, C_CAN_IFACE(MSGCTRL_REG, iface),
 			ctrl_mask & ~(IF_MCONT_MSGLST |
 				IF_MCONT_INTPND | IF_MCONT_NEWDAT));
 	c_can_object_put(dev, iface, obj, IF_COMM_CONTROL);
@@ -374,7 +378,7 @@ static void c_can_handle_lost_msg_obj(struct net_device *dev,
 
 	c_can_object_get(dev, iface, objno, IF_COMM_ALL & ~IF_COMM_TXRQST);
 
-	priv->write_reg(priv, &priv->regs->ifregs[iface].msg_cntrl,
+	priv->write_reg(priv, C_CAN_IFACE(MSGCTRL_REG, iface),
 			IF_MCONT_CLR_MSGLST);
 
 	c_can_object_put(dev, 0, objno, IF_COMM_CONTROL);
@@ -410,8 +414,8 @@ static int c_can_read_msg_object(struct net_device *dev, int iface, int ctrl)
 
 	frame->can_dlc = get_can_dlc(ctrl & 0x0F);
 
-	flags =	priv->read_reg(priv, &priv->regs->ifregs[iface].arb2);
-	val = priv->read_reg(priv, &priv->regs->ifregs[iface].arb1) |
+	flags =	priv->read_reg(priv, C_CAN_IFACE(ARB2_REG, iface));
+	val = priv->read_reg(priv, C_CAN_IFACE(ARB1_REG, iface)) |
 		(flags << 16);
 
 	if (flags & IF_ARB_MSGXTD)
@@ -424,7 +428,7 @@ static int c_can_read_msg_object(struct net_device *dev, int iface, int ctrl)
 	else {
 		for (i = 0; i < frame->can_dlc; i += 2) {
 			data = priv->read_reg(priv,
-				&priv->regs->ifregs[iface].data[i / 2]);
+				C_CAN_IFACE(DATA1_REG, iface) + i / 2);
 			frame->data[i] = data;
 			frame->data[i + 1] = data >> 8;
 		}
@@ -444,40 +448,40 @@ static void c_can_setup_receive_object(struct net_device *dev, int iface,
 {
 	struct c_can_priv *priv = netdev_priv(dev);
 
-	priv->write_reg(priv, &priv->regs->ifregs[iface].mask1,
+	priv->write_reg(priv, C_CAN_IFACE(MASK1_REG, iface),
 			IFX_WRITE_LOW_16BIT(mask));
-	priv->write_reg(priv, &priv->regs->ifregs[iface].mask2,
+	priv->write_reg(priv, C_CAN_IFACE(MASK2_REG, iface),
 			IFX_WRITE_HIGH_16BIT(mask));
 
-	priv->write_reg(priv, &priv->regs->ifregs[iface].arb1,
+	priv->write_reg(priv, C_CAN_IFACE(ARB1_REG, iface),
 			IFX_WRITE_LOW_16BIT(id));
-	priv->write_reg(priv, &priv->regs->ifregs[iface].arb2,
+	priv->write_reg(priv, C_CAN_IFACE(ARB2_REG, iface),
 			(IF_ARB_MSGVAL | IFX_WRITE_HIGH_16BIT(id)));
 
-	priv->write_reg(priv, &priv->regs->ifregs[iface].msg_cntrl, mcont);
+	priv->write_reg(priv, C_CAN_IFACE(MSGCTRL_REG, iface), mcont);
 	c_can_object_put(dev, iface, objno, IF_COMM_ALL & ~IF_COMM_TXRQST);
 
 	netdev_dbg(dev, "obj no:%d, msgval:0x%08x\n", objno,
-			c_can_read_reg32(priv, &priv->regs->msgval1));
+			c_can_read_reg32(priv, C_CAN_MSGVAL1_REG));
 }
 
 static void c_can_inval_msg_object(struct net_device *dev, int iface, int objno)
 {
 	struct c_can_priv *priv = netdev_priv(dev);
 
-	priv->write_reg(priv, &priv->regs->ifregs[iface].arb1, 0);
-	priv->write_reg(priv, &priv->regs->ifregs[iface].arb2, 0);
-	priv->write_reg(priv, &priv->regs->ifregs[iface].msg_cntrl, 0);
+	priv->write_reg(priv, C_CAN_IFACE(ARB1_REG, iface), 0);
+	priv->write_reg(priv, C_CAN_IFACE(ARB2_REG, iface), 0);
+	priv->write_reg(priv, C_CAN_IFACE(MSGCTRL_REG, iface), 0);
 
 	c_can_object_put(dev, iface, objno, IF_COMM_ARB | IF_COMM_CONTROL);
 
 	netdev_dbg(dev, "obj no:%d, msgval:0x%08x\n", objno,
-			c_can_read_reg32(priv, &priv->regs->msgval1));
+			c_can_read_reg32(priv, C_CAN_MSGVAL1_REG));
 }
 
 static inline int c_can_is_next_tx_obj_busy(struct c_can_priv *priv, int objno)
 {
-	int val = c_can_read_reg32(priv, &priv->regs->txrqst1);
+	int val = c_can_read_reg32(priv, C_CAN_TXRQST1_REG);
 
 	/*
 	 * as transmission request register's bit n-1 corresponds to
@@ -540,12 +544,12 @@ static int c_can_set_bittiming(struct net_device *dev)
 	netdev_info(dev,
 		"setting BTR=%04x BRPE=%04x\n", reg_btr, reg_brpe);
 
-	ctrl_save = priv->read_reg(priv, &priv->regs->control);
-	priv->write_reg(priv, &priv->regs->control,
+	ctrl_save = priv->read_reg(priv, C_CAN_CTRL_REG);
+	priv->write_reg(priv, C_CAN_CTRL_REG,
 			ctrl_save | CONTROL_CCE | CONTROL_INIT);
-	priv->write_reg(priv, &priv->regs->btr, reg_btr);
-	priv->write_reg(priv, &priv->regs->brp_ext, reg_brpe);
-	priv->write_reg(priv, &priv->regs->control, ctrl_save);
+	priv->write_reg(priv, C_CAN_BTR_REG, reg_btr);
+	priv->write_reg(priv, C_CAN_BRPEXT_REG, reg_brpe);
+	priv->write_reg(priv, C_CAN_CTRL_REG, ctrl_save);
 
 	return 0;
 }
@@ -587,36 +591,36 @@ static void c_can_chip_config(struct net_device *dev)
 	struct c_can_priv *priv = netdev_priv(dev);
 
 	/* enable automatic retransmission */
-	priv->write_reg(priv, &priv->regs->control,
+	priv->write_reg(priv, C_CAN_CTRL_REG,
 			CONTROL_ENABLE_AR);
 
 	if (priv->can.ctrlmode & (CAN_CTRLMODE_LISTENONLY &
 					CAN_CTRLMODE_LOOPBACK)) {
 		/* loopback + silent mode : useful for hot self-test */
-		priv->write_reg(priv, &priv->regs->control, CONTROL_EIE |
+		priv->write_reg(priv, C_CAN_CTRL_REG, CONTROL_EIE |
 				CONTROL_SIE | CONTROL_IE | CONTROL_TEST);
-		priv->write_reg(priv, &priv->regs->test,
+		priv->write_reg(priv, C_CAN_TEST_REG,
 				TEST_LBACK | TEST_SILENT);
 	} else if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK) {
 		/* loopback mode : useful for self-test function */
-		priv->write_reg(priv, &priv->regs->control, CONTROL_EIE |
+		priv->write_reg(priv, C_CAN_CTRL_REG, CONTROL_EIE |
 				CONTROL_SIE | CONTROL_IE | CONTROL_TEST);
-		priv->write_reg(priv, &priv->regs->test, TEST_LBACK);
+		priv->write_reg(priv, C_CAN_TEST_REG, TEST_LBACK);
 	} else if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY) {
 		/* silent mode : bus-monitoring mode */
-		priv->write_reg(priv, &priv->regs->control, CONTROL_EIE |
+		priv->write_reg(priv, C_CAN_CTRL_REG, CONTROL_EIE |
 				CONTROL_SIE | CONTROL_IE | CONTROL_TEST);
-		priv->write_reg(priv, &priv->regs->test, TEST_SILENT);
+		priv->write_reg(priv, C_CAN_TEST_REG, TEST_SILENT);
 	} else
 		/* normal mode*/
-		priv->write_reg(priv, &priv->regs->control,
+		priv->write_reg(priv, C_CAN_CTRL_REG,
 				CONTROL_EIE | CONTROL_SIE | CONTROL_IE);
 
 	/* configure message objects */
 	c_can_configure_msg_objects(dev);
 
 	/* set a `lec` value so that we can check for updates later */
-	priv->write_reg(priv, &priv->regs->status, LEC_UNUSED);
+	priv->write_reg(priv, C_CAN_STS_REG, LEC_UNUSED);
 
 	/* set bittiming params */
 	c_can_set_bittiming(dev);
@@ -669,7 +673,7 @@ static int c_can_get_berr_counter(const struct net_device *dev,
 	unsigned int reg_err_counter;
 	struct c_can_priv *priv = netdev_priv(dev);
 
-	reg_err_counter = priv->read_reg(priv, &priv->regs->err_cnt);
+	reg_err_counter = priv->read_reg(priv, C_CAN_ERR_CNT_REG);
 	bec->rxerr = (reg_err_counter & ERR_CNT_REC_MASK) >>
 				ERR_CNT_REC_SHIFT;
 	bec->txerr = reg_err_counter & ERR_CNT_TEC_MASK;
@@ -697,12 +701,12 @@ static void c_can_do_tx(struct net_device *dev)
 
 	for (/* nix */; (priv->tx_next - priv->tx_echo) > 0; priv->tx_echo++) {
 		msg_obj_no = get_tx_echo_msg_obj(priv);
-		val = c_can_read_reg32(priv, &priv->regs->txrqst1);
+		val = c_can_read_reg32(priv, C_CAN_TXRQST1_REG);
 		if (!(val & (1 << (msg_obj_no - 1)))) {
 			can_get_echo_skb(dev,
 					msg_obj_no - C_CAN_MSG_OBJ_TX_FIRST);
 			stats->tx_bytes += priv->read_reg(priv,
-					&priv->regs->ifregs[0].msg_cntrl)
+					C_CAN_IFACE(MSGCTRL_REG, 0))
 					& IF_MCONT_DLC_MASK;
 			stats->tx_packets++;
 			c_can_inval_msg_object(dev, 0, msg_obj_no);
@@ -744,11 +748,11 @@ static int c_can_do_rx_poll(struct net_device *dev, int quota)
 	u32 num_rx_pkts = 0;
 	unsigned int msg_obj, msg_ctrl_save;
 	struct c_can_priv *priv = netdev_priv(dev);
-	u32 val = c_can_read_reg32(priv, &priv->regs->intpnd1);
+	u32 val = c_can_read_reg32(priv, C_CAN_INTPND1_REG);
 
 	for (msg_obj = C_CAN_MSG_OBJ_RX_FIRST;
 			msg_obj <= C_CAN_MSG_OBJ_RX_LAST && quota > 0;
-			val = c_can_read_reg32(priv, &priv->regs->intpnd1),
+			val = c_can_read_reg32(priv, C_CAN_INTPND1_REG),
 			msg_obj++) {
 		/*
 		 * as interrupt pending register's bit n-1 corresponds to
@@ -758,7 +762,7 @@ static int c_can_do_rx_poll(struct net_device *dev, int quota)
 			c_can_object_get(dev, 0, msg_obj, IF_COMM_ALL &
 					~IF_COMM_TXRQST);
 			msg_ctrl_save = priv->read_reg(priv,
-					&priv->regs->ifregs[0].msg_cntrl);
+					C_CAN_IFACE(MSGCTRL_REG, 0));
 
 			if (msg_ctrl_save & IF_MCONT_EOB)
 				return num_rx_pkts;
@@ -819,7 +823,7 @@ static int c_can_handle_state_change(struct net_device *dev,
 		return 0;
 
 	c_can_get_berr_counter(dev, &bec);
-	reg_err_counter = priv->read_reg(priv, &priv->regs->err_cnt);
+	reg_err_counter = priv->read_reg(priv, C_CAN_ERR_CNT_REG);
 	rx_err_passive = (reg_err_counter & ERR_CNT_RP_MASK) >>
 				ERR_CNT_RP_SHIFT;
 
@@ -935,7 +939,7 @@ static int c_can_handle_bus_err(struct net_device *dev,
 	}
 
 	/* set a `lec` value so that we can check for updates later */
-	priv->write_reg(priv, &priv->regs->status, LEC_UNUSED);
+	priv->write_reg(priv, C_CAN_STS_REG, LEC_UNUSED);
 
 	netif_receive_skb(skb);
 	stats->rx_packets++;
@@ -959,15 +963,15 @@ static int c_can_poll(struct napi_struct *napi, int quota)
 	/* status events have the highest priority */
 	if (irqstatus == STATUS_INTERRUPT) {
 		priv->current_status = priv->read_reg(priv,
-					&priv->regs->status);
+					C_CAN_STS_REG);
 
 		/* handle Tx/Rx events */
 		if (priv->current_status & STATUS_TXOK)
-			priv->write_reg(priv, &priv->regs->status,
+			priv->write_reg(priv, C_CAN_STS_REG,
 					priv->current_status & ~STATUS_TXOK);
 
 		if (priv->current_status & STATUS_RXOK)
-			priv->write_reg(priv, &priv->regs->status,
+			priv->write_reg(priv, C_CAN_STS_REG,
 					priv->current_status & ~STATUS_RXOK);
 
 		/* handle state changes */
@@ -1033,7 +1037,7 @@ static irqreturn_t c_can_isr(int irq, void *dev_id)
 	struct net_device *dev = (struct net_device *)dev_id;
 	struct c_can_priv *priv = netdev_priv(dev);
 
-	priv->irqstatus = priv->read_reg(priv, &priv->regs->interrupt);
+	priv->irqstatus = priv->read_reg(priv, C_CAN_INT_REG);
 	if (!priv->irqstatus)
 		return IRQ_NONE;
 
diff --git a/drivers/net/can/c_can/c_can.h b/drivers/net/can/c_can/c_can.h
index 5f32d34af507..d1e141e3b99c 100644
--- a/drivers/net/can/c_can/c_can.h
+++ b/drivers/net/can/c_can/c_can.h
@@ -22,43 +22,84 @@
 #ifndef C_CAN_H
 #define C_CAN_H
 
-/* c_can IF registers */
-struct c_can_if_regs {
-	u16 com_req;
-	u16 com_mask;
-	u16 mask1;
-	u16 mask2;
-	u16 arb1;
-	u16 arb2;
-	u16 msg_cntrl;
-	u16 data[4];
-	u16 _reserved[13];
+enum reg {
+	C_CAN_CTRL_REG = 0,
+	C_CAN_STS_REG,
+	C_CAN_ERR_CNT_REG,
+	C_CAN_BTR_REG,
+	C_CAN_INT_REG,
+	C_CAN_TEST_REG,
+	C_CAN_BRPEXT_REG,
+	C_CAN_IF1_COMREQ_REG,
+	C_CAN_IF1_COMMSK_REG,
+	C_CAN_IF1_MASK1_REG,
+	C_CAN_IF1_MASK2_REG,
+	C_CAN_IF1_ARB1_REG,
+	C_CAN_IF1_ARB2_REG,
+	C_CAN_IF1_MSGCTRL_REG,
+	C_CAN_IF1_DATA1_REG,
+	C_CAN_IF1_DATA2_REG,
+	C_CAN_IF1_DATA3_REG,
+	C_CAN_IF1_DATA4_REG,
+	C_CAN_IF2_COMREQ_REG,
+	C_CAN_IF2_COMMSK_REG,
+	C_CAN_IF2_MASK1_REG,
+	C_CAN_IF2_MASK2_REG,
+	C_CAN_IF2_ARB1_REG,
+	C_CAN_IF2_ARB2_REG,
+	C_CAN_IF2_MSGCTRL_REG,
+	C_CAN_IF2_DATA1_REG,
+	C_CAN_IF2_DATA2_REG,
+	C_CAN_IF2_DATA3_REG,
+	C_CAN_IF2_DATA4_REG,
+	C_CAN_TXRQST1_REG,
+	C_CAN_TXRQST2_REG,
+	C_CAN_NEWDAT1_REG,
+	C_CAN_NEWDAT2_REG,
+	C_CAN_INTPND1_REG,
+	C_CAN_INTPND2_REG,
+	C_CAN_MSGVAL1_REG,
+	C_CAN_MSGVAL2_REG,
 };
 
-/* c_can hardware registers */
-struct c_can_regs {
-	u16 control;
-	u16 status;
-	u16 err_cnt;
-	u16 btr;
-	u16 interrupt;
-	u16 test;
-	u16 brp_ext;
-	u16 _reserved1;
-	struct c_can_if_regs ifregs[2]; /* [0] = IF1 and [1] = IF2 */
-	u16 _reserved2[8];
-	u16 txrqst1;
-	u16 txrqst2;
-	u16 _reserved3[6];
-	u16 newdat1;
-	u16 newdat2;
-	u16 _reserved4[6];
-	u16 intpnd1;
-	u16 intpnd2;
-	u16 _reserved5[6];
-	u16 msgval1;
-	u16 msgval2;
-	u16 _reserved6[6];
+static const u16 reg_map_c_can[] = {
+	[C_CAN_CTRL_REG]	= 0x00,
+	[C_CAN_STS_REG]		= 0x02,
+	[C_CAN_ERR_CNT_REG]	= 0x04,
+	[C_CAN_BTR_REG]		= 0x06,
+	[C_CAN_INT_REG]		= 0x08,
+	[C_CAN_TEST_REG]	= 0x0A,
+	[C_CAN_BRPEXT_REG]	= 0x0C,
+	[C_CAN_IF1_COMREQ_REG]	= 0x10,
+	[C_CAN_IF1_COMMSK_REG]	= 0x12,
+	[C_CAN_IF1_MASK1_REG]	= 0x14,
+	[C_CAN_IF1_MASK2_REG]	= 0x16,
+	[C_CAN_IF1_ARB1_REG]	= 0x18,
+	[C_CAN_IF1_ARB2_REG]	= 0x1A,
+	[C_CAN_IF1_MSGCTRL_REG]	= 0x1C,
+	[C_CAN_IF1_DATA1_REG]	= 0x1E,
+	[C_CAN_IF1_DATA2_REG]	= 0x20,
+	[C_CAN_IF1_DATA3_REG]	= 0x22,
+	[C_CAN_IF1_DATA4_REG]	= 0x24,
+	[C_CAN_IF2_COMREQ_REG]	= 0x40,
+	[C_CAN_IF2_COMMSK_REG]	= 0x42,
+	[C_CAN_IF2_MASK1_REG]	= 0x44,
+	[C_CAN_IF2_MASK2_REG]	= 0x46,
+	[C_CAN_IF2_ARB1_REG]	= 0x48,
+	[C_CAN_IF2_ARB2_REG]	= 0x4A,
+	[C_CAN_IF2_MSGCTRL_REG]	= 0x4C,
+	[C_CAN_IF2_DATA1_REG]	= 0x4E,
+	[C_CAN_IF2_DATA2_REG]	= 0x50,
+	[C_CAN_IF2_DATA3_REG]	= 0x52,
+	[C_CAN_IF2_DATA4_REG]	= 0x54,
+	[C_CAN_TXRQST1_REG]	= 0x80,
+	[C_CAN_TXRQST2_REG]	= 0x82,
+	[C_CAN_NEWDAT1_REG]	= 0x90,
+	[C_CAN_NEWDAT2_REG]	= 0x92,
+	[C_CAN_INTPND1_REG]	= 0xA0,
+	[C_CAN_INTPND2_REG]	= 0xA2,
+	[C_CAN_MSGVAL1_REG]	= 0xB0,
+	[C_CAN_MSGVAL2_REG]	= 0xB2,
 };
 
 /* c_can private data structure */
@@ -69,9 +110,10 @@ struct c_can_priv {
 	int tx_object;
 	int current_status;
 	int last_status;
-	u16 (*read_reg) (struct c_can_priv *priv, void *reg);
-	void (*write_reg) (struct c_can_priv *priv, void *reg, u16 val);
-	struct c_can_regs __iomem *regs;
+	u16 (*read_reg) (struct c_can_priv *priv, enum reg index);
+	void (*write_reg) (struct c_can_priv *priv, enum reg index, u16 val);
+	void __iomem *base;
+	const u16 *regs;
 	unsigned long irq_flags; /* for request_irq() */
 	unsigned int tx_next;
 	unsigned int tx_echo;
diff --git a/drivers/net/can/c_can/c_can_platform.c b/drivers/net/can/c_can/c_can_platform.c
index 5e1a5ff6476e..a6e9b937683a 100644
--- a/drivers/net/can/c_can/c_can_platform.c
+++ b/drivers/net/can/c_can/c_can_platform.c
@@ -42,27 +42,27 @@
  * Handle the same by providing a common read/write interface.
  */
 static u16 c_can_plat_read_reg_aligned_to_16bit(struct c_can_priv *priv,
-						void *reg)
+						enum reg index)
 {
-	return readw(reg);
+	return readw(priv->base + priv->regs[index]);
 }
 
 static void c_can_plat_write_reg_aligned_to_16bit(struct c_can_priv *priv,
-						void *reg, u16 val)
+						enum reg index, u16 val)
 {
-	writew(val, reg);
+	writew(val, priv->base + priv->regs[index]);
 }
 
 static u16 c_can_plat_read_reg_aligned_to_32bit(struct c_can_priv *priv,
-						void *reg)
+						enum reg index)
 {
-	return readw(reg + (long)reg - (long)priv->regs);
+	return readw(priv->base + 2 * priv->regs[index]);
 }
 
 static void c_can_plat_write_reg_aligned_to_32bit(struct c_can_priv *priv,
-						void *reg, u16 val)
+						enum reg index, u16 val)
 {
-	writew(val, reg + (long)reg - (long)priv->regs);
+	writew(val, priv->base + 2 * priv->regs[index]);
 }
 
 static int __devinit c_can_plat_probe(struct platform_device *pdev)
@@ -115,9 +115,10 @@ static int __devinit c_can_plat_probe(struct platform_device *pdev)
 	}
 
 	priv = netdev_priv(dev);
+	priv->regs = reg_map_c_can;
 
 	dev->irq = irq;
-	priv->regs = addr;
+	priv->base = addr;
 #ifdef CONFIG_HAVE_CLK
 	priv->can.clock.freq = clk_get_rate(clk);
 	priv->priv = clk;
@@ -146,7 +147,7 @@ static int __devinit c_can_plat_probe(struct platform_device *pdev)
 	}
 
 	dev_info(&pdev->dev, "%s device registered (regs=%p, irq=%d)\n",
-		 KBUILD_MODNAME, priv->regs, dev->irq);
+		 KBUILD_MODNAME, priv->base, dev->irq);
 	return 0;
 
 exit_free_device:
@@ -176,7 +177,7 @@ static int __devexit c_can_plat_remove(struct platform_device *pdev)
 	platform_set_drvdata(pdev, NULL);
 
 	free_c_can_dev(dev);
-	iounmap(priv->regs);
+	iounmap(priv->base);
 
 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	release_mem_region(mem->start, resource_size(mem));