Thread (1 message) 1 message, 1 author, 2011-08-06

[RFC 1/4] [flexcan] Abstract off read/write for big/little endian.

From: Robin Holt <hidden>
Date: 2011-08-06 04:05:01
Subsystem: can network drivers, the rest · Maintainers: Marc Kleine-Budde, Vincent Mailhol, Linus Torvalds

Possibly related (same subject, not in this thread)

First step in converting the flexcan driver from supporting just arm to
supporting both arm and powerpc architectures.

Signed-off-by: Robin Holt <holt-sJ/iWh9BUns@public.gmane.org>
Acked-by: Marc Kleine-Budde <redacted>
To: Wolfgang Grandegger <redacted>
To: U Bhaskar-B22300 <redacted>
Cc: socketcan-core-0fE9KPoRgkgATYTw5x5z8w@public.gmane.org
Cc: netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
---
 drivers/net/can/flexcan.c |  140 ++++++++++++++++++++++++++------------------
 1 files changed, 83 insertions(+), 57 deletions(-)
diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
index 67d9fc0..74b1706 100644
--- a/drivers/net/can/flexcan.c
+++ b/drivers/net/can/flexcan.c
@@ -196,6 +196,31 @@ static struct can_bittiming_const flexcan_bittiming_const = {
 };
 
 /*
+ * Abstract off the read/write for arm versus ppc.
+ */
+#if defined(__BIG_ENDIAN)
+static inline u32 flexcan_read(void __iomem *addr)
+{
+	return in_be32(addr);
+}
+
+static inline void flexcan_write(u32 val, void __iomem *addr)
+{
+	out_be32(addr, val);
+}
+#else
+static inline u32 flexcan_read(void __iomem *addr)
+{
+	return readl(addr);
+}
+
+static inline void flexcan_write(u32 val, void __iomem *addr)
+{
+	writel(val, addr);
+}
+#endif
+
+/*
  * Swtich transceiver on or off
  */
 static void flexcan_transceiver_switch(const struct flexcan_priv *priv, int on)
@@ -216,9 +241,9 @@ static inline void flexcan_chip_enable(struct flexcan_priv *priv)
 	struct flexcan_regs __iomem *regs = priv->base;
 	u32 reg;
 
-	reg = readl(&regs->mcr);
+	reg = flexcan_read(&regs->mcr);
 	reg &= ~FLEXCAN_MCR_MDIS;
-	writel(reg, &regs->mcr);
+	flexcan_write(reg, &regs->mcr);
 
 	udelay(10);
 }
@@ -228,9 +253,9 @@ static inline void flexcan_chip_disable(struct flexcan_priv *priv)
 	struct flexcan_regs __iomem *regs = priv->base;
 	u32 reg;
 
-	reg = readl(&regs->mcr);
+	reg = flexcan_read(&regs->mcr);
 	reg |= FLEXCAN_MCR_MDIS;
-	writel(reg, &regs->mcr);
+	flexcan_write(reg, &regs->mcr);
 }
 
 static int flexcan_get_berr_counter(const struct net_device *dev,
@@ -238,7 +263,7 @@ static int flexcan_get_berr_counter(const struct net_device *dev,
 {
 	const struct flexcan_priv *priv = netdev_priv(dev);
 	struct flexcan_regs __iomem *regs = priv->base;
-	u32 reg = readl(&regs->ecr);
+	u32 reg = flexcan_read(&regs->ecr);
 
 	bec->txerr = (reg >> 0) & 0xff;
 	bec->rxerr = (reg >> 8) & 0xff;
@@ -272,15 +297,15 @@ static int flexcan_start_xmit(struct sk_buff *skb, struct net_device *dev)
 
 	if (cf->can_dlc > 0) {
 		u32 data = be32_to_cpup((__be32 *)&cf->data[0]);
-		writel(data, &regs->cantxfg[FLEXCAN_TX_BUF_ID].data[0]);
+		flexcan_write(data, &regs->cantxfg[FLEXCAN_TX_BUF_ID].data[0]);
 	}
 	if (cf->can_dlc > 3) {
 		u32 data = be32_to_cpup((__be32 *)&cf->data[4]);
-		writel(data, &regs->cantxfg[FLEXCAN_TX_BUF_ID].data[1]);
+		flexcan_write(data, &regs->cantxfg[FLEXCAN_TX_BUF_ID].data[1]);
 	}
 
-	writel(can_id, &regs->cantxfg[FLEXCAN_TX_BUF_ID].can_id);
-	writel(ctrl, &regs->cantxfg[FLEXCAN_TX_BUF_ID].can_ctrl);
+	flexcan_write(can_id, &regs->cantxfg[FLEXCAN_TX_BUF_ID].can_id);
+	flexcan_write(ctrl, &regs->cantxfg[FLEXCAN_TX_BUF_ID].can_ctrl);
 
 	kfree_skb(skb);
 
@@ -468,8 +493,8 @@ static void flexcan_read_fifo(const struct net_device *dev,
 	struct flexcan_mb __iomem *mb = &regs->cantxfg[0];
 	u32 reg_ctrl, reg_id;
 
-	reg_ctrl = readl(&mb->can_ctrl);
-	reg_id = readl(&mb->can_id);
+	reg_ctrl = flexcan_read(&mb->can_ctrl);
+	reg_id = flexcan_read(&mb->can_id);
 	if (reg_ctrl & FLEXCAN_MB_CNT_IDE)
 		cf->can_id = ((reg_id >> 0) & CAN_EFF_MASK) | CAN_EFF_FLAG;
 	else
@@ -479,12 +504,12 @@ static void flexcan_read_fifo(const struct net_device *dev,
 		cf->can_id |= CAN_RTR_FLAG;
 	cf->can_dlc = get_can_dlc((reg_ctrl >> 16) & 0xf);
 
-	*(__be32 *)(cf->data + 0) = cpu_to_be32(readl(&mb->data[0]));
-	*(__be32 *)(cf->data + 4) = cpu_to_be32(readl(&mb->data[1]));
+	*(__be32 *)(cf->data + 0) = cpu_to_be32(flexcan_read(&mb->data[0]));
+	*(__be32 *)(cf->data + 4) = cpu_to_be32(flexcan_read(&mb->data[1]));
 
 	/* mark as read */
-	writel(FLEXCAN_IFLAG_RX_FIFO_AVAILABLE, &regs->iflag1);
-	readl(&regs->timer);
+	flexcan_write(FLEXCAN_IFLAG_RX_FIFO_AVAILABLE, &regs->iflag1);
+	flexcan_read(&regs->timer);
 }
 
 static int flexcan_read_frame(struct net_device *dev)
@@ -520,17 +545,17 @@ static int flexcan_poll(struct napi_struct *napi, int quota)
 	 * The error bits are cleared on read,
 	 * use saved value from irq handler.
 	 */
-	reg_esr = readl(&regs->esr) | priv->reg_esr;
+	reg_esr = flexcan_read(&regs->esr) | priv->reg_esr;
 
 	/* handle state changes */
 	work_done += flexcan_poll_state(dev, reg_esr);
 
 	/* handle RX-FIFO */
-	reg_iflag1 = readl(&regs->iflag1);
+	reg_iflag1 = flexcan_read(&regs->iflag1);
 	while (reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_AVAILABLE &&
 	       work_done < quota) {
 		work_done += flexcan_read_frame(dev);
-		reg_iflag1 = readl(&regs->iflag1);
+		reg_iflag1 = flexcan_read(&regs->iflag1);
 	}
 
 	/* report bus errors */
@@ -540,8 +565,8 @@ static int flexcan_poll(struct napi_struct *napi, int quota)
 	if (work_done < quota) {
 		napi_complete(napi);
 		/* enable IRQs */
-		writel(FLEXCAN_IFLAG_DEFAULT, &regs->imask1);
-		writel(priv->reg_ctrl_default, &regs->ctrl);
+		flexcan_write(FLEXCAN_IFLAG_DEFAULT, &regs->imask1);
+		flexcan_write(priv->reg_ctrl_default, &regs->ctrl);
 	}
 
 	return work_done;
@@ -555,9 +580,9 @@ static irqreturn_t flexcan_irq(int irq, void *dev_id)
 	struct flexcan_regs __iomem *regs = priv->base;
 	u32 reg_iflag1, reg_esr;
 
-	reg_iflag1 = readl(&regs->iflag1);
-	reg_esr = readl(&regs->esr);
-	writel(FLEXCAN_ESR_ERR_INT, &regs->esr);	/* ACK err IRQ */
+	reg_iflag1 = flexcan_read(&regs->iflag1);
+	reg_esr = flexcan_read(&regs->esr);
+	flexcan_write(FLEXCAN_ESR_ERR_INT, &regs->esr);	/* ACK err IRQ */
 
 	/*
 	 * schedule NAPI in case of:
@@ -573,16 +598,16 @@ static irqreturn_t flexcan_irq(int irq, void *dev_id)
 		 * save them for later use.
 		 */
 		priv->reg_esr = reg_esr & FLEXCAN_ESR_ERR_BUS;
-		writel(FLEXCAN_IFLAG_DEFAULT & ~FLEXCAN_IFLAG_RX_FIFO_AVAILABLE,
-		       &regs->imask1);
-		writel(priv->reg_ctrl_default & ~FLEXCAN_CTRL_ERR_ALL,
+		flexcan_write(FLEXCAN_IFLAG_DEFAULT &
+			~FLEXCAN_IFLAG_RX_FIFO_AVAILABLE, &regs->imask1);
+		flexcan_write(priv->reg_ctrl_default & ~FLEXCAN_CTRL_ERR_ALL,
 		       &regs->ctrl);
 		napi_schedule(&priv->napi);
 	}
 
 	/* FIFO overflow */
 	if (reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_OVERFLOW) {
-		writel(FLEXCAN_IFLAG_RX_FIFO_OVERFLOW, &regs->iflag1);
+		flexcan_write(FLEXCAN_IFLAG_RX_FIFO_OVERFLOW, &regs->iflag1);
 		dev->stats.rx_over_errors++;
 		dev->stats.rx_errors++;
 	}
@@ -591,7 +616,7 @@ static irqreturn_t flexcan_irq(int irq, void *dev_id)
 	if (reg_iflag1 & (1 << FLEXCAN_TX_BUF_ID)) {
 		/* tx_bytes is incremented in flexcan_start_xmit */
 		stats->tx_packets++;
-		writel((1 << FLEXCAN_TX_BUF_ID), &regs->iflag1);
+		flexcan_write((1 << FLEXCAN_TX_BUF_ID), &regs->iflag1);
 		netif_wake_queue(dev);
 	}
 
@@ -605,7 +630,7 @@ static void flexcan_set_bittiming(struct net_device *dev)
 	struct flexcan_regs __iomem *regs = priv->base;
 	u32 reg;
 
-	reg = readl(&regs->ctrl);
+	reg = flexcan_read(&regs->ctrl);
 	reg &= ~(FLEXCAN_CTRL_PRESDIV(0xff) |
 		 FLEXCAN_CTRL_RJW(0x3) |
 		 FLEXCAN_CTRL_PSEG1(0x7) |
@@ -629,11 +654,11 @@ static void flexcan_set_bittiming(struct net_device *dev)
 		reg |= FLEXCAN_CTRL_SMP;
 
 	dev_info(dev->dev.parent, "writing ctrl=0x%08x\n", reg);
-	writel(reg, &regs->ctrl);
+	flexcan_write(reg, &regs->ctrl);
 
 	/* print chip status */
 	dev_dbg(dev->dev.parent, "%s: mcr=0x%08x ctrl=0x%08x\n", __func__,
-		readl(&regs->mcr), readl(&regs->ctrl));
+		flexcan_read(&regs->mcr), flexcan_read(&regs->ctrl));
 }
 
 /*
@@ -654,10 +679,10 @@ static int flexcan_chip_start(struct net_device *dev)
 	flexcan_chip_enable(priv);
 
 	/* soft reset */
-	writel(FLEXCAN_MCR_SOFTRST, &regs->mcr);
+	flexcan_write(FLEXCAN_MCR_SOFTRST, &regs->mcr);
 	udelay(10);
 
-	reg_mcr = readl(&regs->mcr);
+	reg_mcr = flexcan_read(&regs->mcr);
 	if (reg_mcr & FLEXCAN_MCR_SOFTRST) {
 		dev_err(dev->dev.parent,
 			"Failed to softreset can module (mcr=0x%08x)\n",
@@ -679,12 +704,12 @@ static int flexcan_chip_start(struct net_device *dev)
 	 * choose format C
 	 *
 	 */
-	reg_mcr = readl(&regs->mcr);
+	reg_mcr = flexcan_read(&regs->mcr);
 	reg_mcr |= FLEXCAN_MCR_FRZ | FLEXCAN_MCR_FEN | FLEXCAN_MCR_HALT |
 		FLEXCAN_MCR_SUPV | FLEXCAN_MCR_WRN_EN |
 		FLEXCAN_MCR_IDAM_C;
 	dev_dbg(dev->dev.parent, "%s: writing mcr=0x%08x", __func__, reg_mcr);
-	writel(reg_mcr, &regs->mcr);
+	flexcan_write(reg_mcr, &regs->mcr);
 
 	/*
 	 * CTRL
@@ -702,7 +727,7 @@ static int flexcan_chip_start(struct net_device *dev)
 	 * (FLEXCAN_CTRL_ERR_MSK), too. Otherwise we don't get any
 	 * warning or bus passive interrupts.
 	 */
-	reg_ctrl = readl(&regs->ctrl);
+	reg_ctrl = flexcan_read(&regs->ctrl);
 	reg_ctrl &= ~FLEXCAN_CTRL_TSYN;
 	reg_ctrl |= FLEXCAN_CTRL_BOFF_REC | FLEXCAN_CTRL_LBUF |
 		FLEXCAN_CTRL_ERR_STATE | FLEXCAN_CTRL_ERR_MSK;
@@ -710,38 +735,39 @@ static int flexcan_chip_start(struct net_device *dev)
 	/* save for later use */
 	priv->reg_ctrl_default = reg_ctrl;
 	dev_dbg(dev->dev.parent, "%s: writing ctrl=0x%08x", __func__, reg_ctrl);
-	writel(reg_ctrl, &regs->ctrl);
+	flexcan_write(reg_ctrl, &regs->ctrl);
 
 	for (i = 0; i < ARRAY_SIZE(regs->cantxfg); i++) {
-		writel(0, &regs->cantxfg[i].can_ctrl);
-		writel(0, &regs->cantxfg[i].can_id);
-		writel(0, &regs->cantxfg[i].data[0]);
-		writel(0, &regs->cantxfg[i].data[1]);
+		flexcan_write(0, &regs->cantxfg[i].can_ctrl);
+		flexcan_write(0, &regs->cantxfg[i].can_id);
+		flexcan_write(0, &regs->cantxfg[i].data[0]);
+		flexcan_write(0, &regs->cantxfg[i].data[1]);
 
 		/* put MB into rx queue */
-		writel(FLEXCAN_MB_CNT_CODE(0x4), &regs->cantxfg[i].can_ctrl);
+		flexcan_write(FLEXCAN_MB_CNT_CODE(0x4),
+			&regs->cantxfg[i].can_ctrl);
 	}
 
 	/* acceptance mask/acceptance code (accept everything) */
-	writel(0x0, &regs->rxgmask);
-	writel(0x0, &regs->rx14mask);
-	writel(0x0, &regs->rx15mask);
+	flexcan_write(0x0, &regs->rxgmask);
+	flexcan_write(0x0, &regs->rx14mask);
+	flexcan_write(0x0, &regs->rx15mask);
 
 	flexcan_transceiver_switch(priv, 1);
 
 	/* synchronize with the can bus */
-	reg_mcr = readl(&regs->mcr);
+	reg_mcr = flexcan_read(&regs->mcr);
 	reg_mcr &= ~FLEXCAN_MCR_HALT;
-	writel(reg_mcr, &regs->mcr);
+	flexcan_write(reg_mcr, &regs->mcr);
 
 	priv->can.state = CAN_STATE_ERROR_ACTIVE;
 
 	/* enable FIFO interrupts */
-	writel(FLEXCAN_IFLAG_DEFAULT, &regs->imask1);
+	flexcan_write(FLEXCAN_IFLAG_DEFAULT, &regs->imask1);
 
 	/* print chip status */
 	dev_dbg(dev->dev.parent, "%s: reading mcr=0x%08x ctrl=0x%08x\n",
-		__func__, readl(&regs->mcr), readl(&regs->ctrl));
+		__func__, flexcan_read(&regs->mcr), flexcan_read(&regs->ctrl));
 
 	return 0;
 
@@ -763,12 +789,12 @@ static void flexcan_chip_stop(struct net_device *dev)
 	u32 reg;
 
 	/* Disable all interrupts */
-	writel(0, &regs->imask1);
+	flexcan_write(0, &regs->imask1);
 
 	/* Disable + halt module */
-	reg = readl(&regs->mcr);
+	reg = flexcan_read(&regs->mcr);
 	reg |= FLEXCAN_MCR_MDIS | FLEXCAN_MCR_HALT;
-	writel(reg, &regs->mcr);
+	flexcan_write(reg, &regs->mcr);
 
 	flexcan_transceiver_switch(priv, 0);
 	priv->can.state = CAN_STATE_STOPPED;
@@ -860,24 +886,24 @@ static int __devinit register_flexcandev(struct net_device *dev)
 
 	/* select "bus clock", chip must be disabled */
 	flexcan_chip_disable(priv);
-	reg = readl(&regs->ctrl);
+	reg = flexcan_read(&regs->ctrl);
 	reg |= FLEXCAN_CTRL_CLK_SRC;
-	writel(reg, &regs->ctrl);
+	flexcan_write(reg, &regs->ctrl);
 
 	flexcan_chip_enable(priv);
 
 	/* set freeze, halt and activate FIFO, restrict register access */
-	reg = readl(&regs->mcr);
+	reg = flexcan_read(&regs->mcr);
 	reg |= FLEXCAN_MCR_FRZ | FLEXCAN_MCR_HALT |
 		FLEXCAN_MCR_FEN | FLEXCAN_MCR_SUPV;
-	writel(reg, &regs->mcr);
+	flexcan_write(reg, &regs->mcr);
 
 	/*
 	 * Currently we only support newer versions of this core
 	 * featuring a RX FIFO. Older cores found on some Coldfire
 	 * derivates are not yet supported.
 	 */
-	reg = readl(&regs->mcr);
+	reg = flexcan_read(&regs->mcr);
 	if (!(reg & FLEXCAN_MCR_FEN)) {
 		dev_err(dev->dev.parent,
 			"Could not enable RX FIFO, unsupported core\n");
-- 
1.7.2.1
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