zte's code,first commit

Change-Id: I9a04da59e459a9bc0d67f101f700d9d7dc8d681b
diff --git a/ap/os/linux/linux-3.4.x/drivers/net/can/flexcan.c b/ap/os/linux/linux-3.4.x/drivers/net/can/flexcan.c
new file mode 100644
index 0000000..b523e65
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/drivers/net/can/flexcan.c
@@ -0,0 +1,1099 @@
+/*
+ * flexcan.c - FLEXCAN CAN controller driver
+ *
+ * Copyright (c) 2005-2006 Varma Electronics Oy
+ * Copyright (c) 2009 Sascha Hauer, Pengutronix
+ * Copyright (c) 2010 Marc Kleine-Budde, Pengutronix
+ *
+ * Based on code originally by Andrey Volkov <avolkov@varma-el.com>
+ *
+ * LICENCE:
+ * 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 in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/netdevice.h>
+#include <linux/can.h>
+#include <linux/can/dev.h>
+#include <linux/can/error.h>
+#include <linux/can/platform/flexcan.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/if_arp.h>
+#include <linux/if_ether.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+
+#define DRV_NAME			"flexcan"
+
+/* 8 for RX fifo and 2 error handling */
+#define FLEXCAN_NAPI_WEIGHT		(8 + 2)
+
+/* FLEXCAN module configuration register (CANMCR) bits */
+#define FLEXCAN_MCR_MDIS		BIT(31)
+#define FLEXCAN_MCR_FRZ			BIT(30)
+#define FLEXCAN_MCR_FEN			BIT(29)
+#define FLEXCAN_MCR_HALT		BIT(28)
+#define FLEXCAN_MCR_NOT_RDY		BIT(27)
+#define FLEXCAN_MCR_WAK_MSK		BIT(26)
+#define FLEXCAN_MCR_SOFTRST		BIT(25)
+#define FLEXCAN_MCR_FRZ_ACK		BIT(24)
+#define FLEXCAN_MCR_SUPV		BIT(23)
+#define FLEXCAN_MCR_SLF_WAK		BIT(22)
+#define FLEXCAN_MCR_WRN_EN		BIT(21)
+#define FLEXCAN_MCR_LPM_ACK		BIT(20)
+#define FLEXCAN_MCR_WAK_SRC		BIT(19)
+#define FLEXCAN_MCR_DOZE		BIT(18)
+#define FLEXCAN_MCR_SRX_DIS		BIT(17)
+#define FLEXCAN_MCR_BCC			BIT(16)
+#define FLEXCAN_MCR_LPRIO_EN		BIT(13)
+#define FLEXCAN_MCR_AEN			BIT(12)
+#define FLEXCAN_MCR_MAXMB(x)		((x) & 0x1f)
+#define FLEXCAN_MCR_IDAM_A		(0 << 8)
+#define FLEXCAN_MCR_IDAM_B		(1 << 8)
+#define FLEXCAN_MCR_IDAM_C		(2 << 8)
+#define FLEXCAN_MCR_IDAM_D		(3 << 8)
+
+/* FLEXCAN control register (CANCTRL) bits */
+#define FLEXCAN_CTRL_PRESDIV(x)		(((x) & 0xff) << 24)
+#define FLEXCAN_CTRL_RJW(x)		(((x) & 0x03) << 22)
+#define FLEXCAN_CTRL_PSEG1(x)		(((x) & 0x07) << 19)
+#define FLEXCAN_CTRL_PSEG2(x)		(((x) & 0x07) << 16)
+#define FLEXCAN_CTRL_BOFF_MSK		BIT(15)
+#define FLEXCAN_CTRL_ERR_MSK		BIT(14)
+#define FLEXCAN_CTRL_CLK_SRC		BIT(13)
+#define FLEXCAN_CTRL_LPB		BIT(12)
+#define FLEXCAN_CTRL_TWRN_MSK		BIT(11)
+#define FLEXCAN_CTRL_RWRN_MSK		BIT(10)
+#define FLEXCAN_CTRL_SMP		BIT(7)
+#define FLEXCAN_CTRL_BOFF_REC		BIT(6)
+#define FLEXCAN_CTRL_TSYN		BIT(5)
+#define FLEXCAN_CTRL_LBUF		BIT(4)
+#define FLEXCAN_CTRL_LOM		BIT(3)
+#define FLEXCAN_CTRL_PROPSEG(x)		((x) & 0x07)
+#define FLEXCAN_CTRL_ERR_BUS		(FLEXCAN_CTRL_ERR_MSK)
+#define FLEXCAN_CTRL_ERR_STATE \
+	(FLEXCAN_CTRL_TWRN_MSK | FLEXCAN_CTRL_RWRN_MSK | \
+	 FLEXCAN_CTRL_BOFF_MSK)
+#define FLEXCAN_CTRL_ERR_ALL \
+	(FLEXCAN_CTRL_ERR_BUS | FLEXCAN_CTRL_ERR_STATE)
+
+/* FLEXCAN error and status register (ESR) bits */
+#define FLEXCAN_ESR_TWRN_INT		BIT(17)
+#define FLEXCAN_ESR_RWRN_INT		BIT(16)
+#define FLEXCAN_ESR_BIT1_ERR		BIT(15)
+#define FLEXCAN_ESR_BIT0_ERR		BIT(14)
+#define FLEXCAN_ESR_ACK_ERR		BIT(13)
+#define FLEXCAN_ESR_CRC_ERR		BIT(12)
+#define FLEXCAN_ESR_FRM_ERR		BIT(11)
+#define FLEXCAN_ESR_STF_ERR		BIT(10)
+#define FLEXCAN_ESR_TX_WRN		BIT(9)
+#define FLEXCAN_ESR_RX_WRN		BIT(8)
+#define FLEXCAN_ESR_IDLE		BIT(7)
+#define FLEXCAN_ESR_TXRX		BIT(6)
+#define FLEXCAN_EST_FLT_CONF_SHIFT	(4)
+#define FLEXCAN_ESR_FLT_CONF_MASK	(0x3 << FLEXCAN_EST_FLT_CONF_SHIFT)
+#define FLEXCAN_ESR_FLT_CONF_ACTIVE	(0x0 << FLEXCAN_EST_FLT_CONF_SHIFT)
+#define FLEXCAN_ESR_FLT_CONF_PASSIVE	(0x1 << FLEXCAN_EST_FLT_CONF_SHIFT)
+#define FLEXCAN_ESR_BOFF_INT		BIT(2)
+#define FLEXCAN_ESR_ERR_INT		BIT(1)
+#define FLEXCAN_ESR_WAK_INT		BIT(0)
+#define FLEXCAN_ESR_ERR_BUS \
+	(FLEXCAN_ESR_BIT1_ERR | FLEXCAN_ESR_BIT0_ERR | \
+	 FLEXCAN_ESR_ACK_ERR | FLEXCAN_ESR_CRC_ERR | \
+	 FLEXCAN_ESR_FRM_ERR | FLEXCAN_ESR_STF_ERR)
+#define FLEXCAN_ESR_ERR_STATE \
+	(FLEXCAN_ESR_TWRN_INT | FLEXCAN_ESR_RWRN_INT | FLEXCAN_ESR_BOFF_INT)
+#define FLEXCAN_ESR_ERR_ALL \
+	(FLEXCAN_ESR_ERR_BUS | FLEXCAN_ESR_ERR_STATE)
+#define FLEXCAN_ESR_ALL_INT \
+	(FLEXCAN_ESR_TWRN_INT | FLEXCAN_ESR_RWRN_INT | \
+	 FLEXCAN_ESR_BOFF_INT | FLEXCAN_ESR_ERR_INT)
+
+/* FLEXCAN interrupt flag register (IFLAG) bits */
+/* Errata ERR005829 step7: Reserve first valid MB */
+#define FLEXCAN_TX_BUF_RESERVED		8
+#define FLEXCAN_TX_BUF_ID		9
+#define FLEXCAN_IFLAG_BUF(x)		BIT(x)
+#define FLEXCAN_IFLAG_RX_FIFO_OVERFLOW	BIT(7)
+#define FLEXCAN_IFLAG_RX_FIFO_WARN	BIT(6)
+#define FLEXCAN_IFLAG_RX_FIFO_AVAILABLE	BIT(5)
+#define FLEXCAN_IFLAG_DEFAULT \
+	(FLEXCAN_IFLAG_RX_FIFO_OVERFLOW | FLEXCAN_IFLAG_RX_FIFO_AVAILABLE | \
+	 FLEXCAN_IFLAG_BUF(FLEXCAN_TX_BUF_ID))
+
+/* FLEXCAN message buffers */
+#define FLEXCAN_MB_CNT_CODE(x)		(((x) & 0xf) << 24)
+#define FLEXCAN_MB_CODE_RX_INACTIVE	(0x0 << 24)
+#define FLEXCAN_MB_CODE_RX_EMPTY	(0x4 << 24)
+#define FLEXCAN_MB_CODE_RX_FULL		(0x2 << 24)
+#define FLEXCAN_MB_CODE_RX_OVERRRUN	(0x6 << 24)
+#define FLEXCAN_MB_CODE_RX_RANSWER	(0xa << 24)
+
+#define FLEXCAN_MB_CODE_TX_INACTIVE	(0x8 << 24)
+#define FLEXCAN_MB_CODE_TX_ABORT	(0x9 << 24)
+#define FLEXCAN_MB_CODE_TX_DATA		(0xc << 24)
+#define FLEXCAN_MB_CODE_TX_TANSWER	(0xe << 24)
+
+#define FLEXCAN_MB_CNT_SRR		BIT(22)
+#define FLEXCAN_MB_CNT_IDE		BIT(21)
+#define FLEXCAN_MB_CNT_RTR		BIT(20)
+#define FLEXCAN_MB_CNT_LENGTH(x)	(((x) & 0xf) << 16)
+#define FLEXCAN_MB_CNT_TIMESTAMP(x)	((x) & 0xffff)
+
+#define FLEXCAN_MB_CODE_MASK		(0xf0ffffff)
+
+/* Structure of the message buffer */
+struct flexcan_mb {
+	u32 can_ctrl;
+	u32 can_id;
+	u32 data[2];
+};
+
+/* Structure of the hardware registers */
+struct flexcan_regs {
+	u32 mcr;		/* 0x00 */
+	u32 ctrl;		/* 0x04 */
+	u32 timer;		/* 0x08 */
+	u32 _reserved1;		/* 0x0c */
+	u32 rxgmask;		/* 0x10 */
+	u32 rx14mask;		/* 0x14 */
+	u32 rx15mask;		/* 0x18 */
+	u32 ecr;		/* 0x1c */
+	u32 esr;		/* 0x20 */
+	u32 imask2;		/* 0x24 */
+	u32 imask1;		/* 0x28 */
+	u32 iflag2;		/* 0x2c */
+	u32 iflag1;		/* 0x30 */
+	u32 _reserved2[19];
+	struct flexcan_mb cantxfg[64];
+};
+
+struct flexcan_priv {
+	struct can_priv can;
+	struct net_device *dev;
+	struct napi_struct napi;
+
+	void __iomem *base;
+	u32 reg_esr;
+	u32 reg_ctrl_default;
+
+	struct clk *clk;
+	struct flexcan_platform_data *pdata;
+};
+
+static struct can_bittiming_const flexcan_bittiming_const = {
+	.name = DRV_NAME,
+	.tseg1_min = 4,
+	.tseg1_max = 16,
+	.tseg2_min = 2,
+	.tseg2_max = 8,
+	.sjw_max = 4,
+	.brp_min = 1,
+	.brp_max = 256,
+	.brp_inc = 1,
+};
+
+/*
+ * 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)
+{
+	if (priv->pdata && priv->pdata->transceiver_switch)
+		priv->pdata->transceiver_switch(on);
+}
+
+static inline int flexcan_has_and_handle_berr(const struct flexcan_priv *priv,
+					      u32 reg_esr)
+{
+	return (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING) &&
+		(reg_esr & FLEXCAN_ESR_ERR_BUS);
+}
+
+static inline void flexcan_chip_enable(struct flexcan_priv *priv)
+{
+	struct flexcan_regs __iomem *regs = priv->base;
+	u32 reg;
+
+	reg = flexcan_read(&regs->mcr);
+	reg &= ~FLEXCAN_MCR_MDIS;
+	flexcan_write(reg, &regs->mcr);
+
+	udelay(10);
+}
+
+static inline void flexcan_chip_disable(struct flexcan_priv *priv)
+{
+	struct flexcan_regs __iomem *regs = priv->base;
+	u32 reg;
+
+	reg = flexcan_read(&regs->mcr);
+	reg |= FLEXCAN_MCR_MDIS;
+	flexcan_write(reg, &regs->mcr);
+}
+
+static int flexcan_get_berr_counter(const struct net_device *dev,
+				    struct can_berr_counter *bec)
+{
+	const struct flexcan_priv *priv = netdev_priv(dev);
+	struct flexcan_regs __iomem *regs = priv->base;
+	u32 reg = flexcan_read(&regs->ecr);
+
+	bec->txerr = (reg >> 0) & 0xff;
+	bec->rxerr = (reg >> 8) & 0xff;
+
+	return 0;
+}
+
+static int flexcan_start_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+	const struct flexcan_priv *priv = netdev_priv(dev);
+	struct flexcan_regs __iomem *regs = priv->base;
+	struct can_frame *cf = (struct can_frame *)skb->data;
+	u32 can_id;
+	u32 ctrl = FLEXCAN_MB_CNT_CODE(0xc) | (cf->can_dlc << 16);
+
+	if (can_dropped_invalid_skb(dev, skb))
+		return NETDEV_TX_OK;
+
+	netif_stop_queue(dev);
+
+	if (cf->can_id & CAN_EFF_FLAG) {
+		can_id = cf->can_id & CAN_EFF_MASK;
+		ctrl |= FLEXCAN_MB_CNT_IDE | FLEXCAN_MB_CNT_SRR;
+	} else {
+		can_id = (cf->can_id & CAN_SFF_MASK) << 18;
+	}
+
+	if (cf->can_id & CAN_RTR_FLAG)
+		ctrl |= FLEXCAN_MB_CNT_RTR;
+
+	if (cf->can_dlc > 0) {
+		u32 data = be32_to_cpup((__be32 *)&cf->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]);
+		flexcan_write(data, &regs->cantxfg[FLEXCAN_TX_BUF_ID].data[1]);
+	}
+
+	can_put_echo_skb(skb, dev, 0);
+
+	flexcan_write(can_id, &regs->cantxfg[FLEXCAN_TX_BUF_ID].can_id);
+	flexcan_write(ctrl, &regs->cantxfg[FLEXCAN_TX_BUF_ID].can_ctrl);
+
+	/* Errata ERR005829 step8:
+	 * Write twice INACTIVE(0x8) code to first MB.
+	 */
+	flexcan_write(FLEXCAN_MB_CODE_TX_INACTIVE,
+		      &regs->cantxfg[FLEXCAN_TX_BUF_RESERVED].can_ctrl);
+	flexcan_write(FLEXCAN_MB_CODE_TX_INACTIVE,
+		      &regs->cantxfg[FLEXCAN_TX_BUF_RESERVED].can_ctrl);
+
+	return NETDEV_TX_OK;
+}
+
+static void do_bus_err(struct net_device *dev,
+		       struct can_frame *cf, u32 reg_esr)
+{
+	struct flexcan_priv *priv = netdev_priv(dev);
+	int rx_errors = 0, tx_errors = 0;
+
+	cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
+
+	if (reg_esr & FLEXCAN_ESR_BIT1_ERR) {
+		netdev_dbg(dev, "BIT1_ERR irq\n");
+		cf->data[2] |= CAN_ERR_PROT_BIT1;
+		tx_errors = 1;
+	}
+	if (reg_esr & FLEXCAN_ESR_BIT0_ERR) {
+		netdev_dbg(dev, "BIT0_ERR irq\n");
+		cf->data[2] |= CAN_ERR_PROT_BIT0;
+		tx_errors = 1;
+	}
+	if (reg_esr & FLEXCAN_ESR_ACK_ERR) {
+		netdev_dbg(dev, "ACK_ERR irq\n");
+		cf->can_id |= CAN_ERR_ACK;
+		cf->data[3] |= CAN_ERR_PROT_LOC_ACK;
+		tx_errors = 1;
+	}
+	if (reg_esr & FLEXCAN_ESR_CRC_ERR) {
+		netdev_dbg(dev, "CRC_ERR irq\n");
+		cf->data[2] |= CAN_ERR_PROT_BIT;
+		cf->data[3] |= CAN_ERR_PROT_LOC_CRC_SEQ;
+		rx_errors = 1;
+	}
+	if (reg_esr & FLEXCAN_ESR_FRM_ERR) {
+		netdev_dbg(dev, "FRM_ERR irq\n");
+		cf->data[2] |= CAN_ERR_PROT_FORM;
+		rx_errors = 1;
+	}
+	if (reg_esr & FLEXCAN_ESR_STF_ERR) {
+		netdev_dbg(dev, "STF_ERR irq\n");
+		cf->data[2] |= CAN_ERR_PROT_STUFF;
+		rx_errors = 1;
+	}
+
+	priv->can.can_stats.bus_error++;
+	if (rx_errors)
+		dev->stats.rx_errors++;
+	if (tx_errors)
+		dev->stats.tx_errors++;
+}
+
+static int flexcan_poll_bus_err(struct net_device *dev, u32 reg_esr)
+{
+	struct sk_buff *skb;
+	struct can_frame *cf;
+
+	skb = alloc_can_err_skb(dev, &cf);
+	if (unlikely(!skb))
+		return 0;
+
+	do_bus_err(dev, cf, reg_esr);
+	netif_receive_skb(skb);
+
+	dev->stats.rx_packets++;
+	dev->stats.rx_bytes += cf->can_dlc;
+
+	return 1;
+}
+
+static void do_state(struct net_device *dev,
+		     struct can_frame *cf, enum can_state new_state)
+{
+	struct flexcan_priv *priv = netdev_priv(dev);
+	struct can_berr_counter bec;
+
+	flexcan_get_berr_counter(dev, &bec);
+
+	switch (priv->can.state) {
+	case CAN_STATE_ERROR_ACTIVE:
+		/*
+		 * from: ERROR_ACTIVE
+		 * to  : ERROR_WARNING, ERROR_PASSIVE, BUS_OFF
+		 * =>  : there was a warning int
+		 */
+		if (new_state >= CAN_STATE_ERROR_WARNING &&
+		    new_state <= CAN_STATE_BUS_OFF) {
+			netdev_dbg(dev, "Error Warning IRQ\n");
+			priv->can.can_stats.error_warning++;
+
+			cf->can_id |= CAN_ERR_CRTL;
+			cf->data[1] = (bec.txerr > bec.rxerr) ?
+				CAN_ERR_CRTL_TX_WARNING :
+				CAN_ERR_CRTL_RX_WARNING;
+		}
+	case CAN_STATE_ERROR_WARNING:	/* fallthrough */
+		/*
+		 * from: ERROR_ACTIVE, ERROR_WARNING
+		 * to  : ERROR_PASSIVE, BUS_OFF
+		 * =>  : error passive int
+		 */
+		if (new_state >= CAN_STATE_ERROR_PASSIVE &&
+		    new_state <= CAN_STATE_BUS_OFF) {
+			netdev_dbg(dev, "Error Passive IRQ\n");
+			priv->can.can_stats.error_passive++;
+
+			cf->can_id |= CAN_ERR_CRTL;
+			cf->data[1] = (bec.txerr > bec.rxerr) ?
+				CAN_ERR_CRTL_TX_PASSIVE :
+				CAN_ERR_CRTL_RX_PASSIVE;
+		}
+		break;
+	case CAN_STATE_BUS_OFF:
+		netdev_err(dev, "BUG! "
+			   "hardware recovered automatically from BUS_OFF\n");
+		break;
+	default:
+		break;
+	}
+
+	/* process state changes depending on the new state */
+	switch (new_state) {
+	case CAN_STATE_ERROR_ACTIVE:
+		netdev_dbg(dev, "Error Active\n");
+		cf->can_id |= CAN_ERR_PROT;
+		cf->data[2] = CAN_ERR_PROT_ACTIVE;
+		break;
+	case CAN_STATE_BUS_OFF:
+		cf->can_id |= CAN_ERR_BUSOFF;
+		can_bus_off(dev);
+		break;
+	default:
+		break;
+	}
+}
+
+static int flexcan_poll_state(struct net_device *dev, u32 reg_esr)
+{
+	struct flexcan_priv *priv = netdev_priv(dev);
+	struct sk_buff *skb;
+	struct can_frame *cf;
+	enum can_state new_state;
+	int flt;
+
+	flt = reg_esr & FLEXCAN_ESR_FLT_CONF_MASK;
+	if (likely(flt == FLEXCAN_ESR_FLT_CONF_ACTIVE)) {
+		if (likely(!(reg_esr & (FLEXCAN_ESR_TX_WRN |
+					FLEXCAN_ESR_RX_WRN))))
+			new_state = CAN_STATE_ERROR_ACTIVE;
+		else
+			new_state = CAN_STATE_ERROR_WARNING;
+	} else if (unlikely(flt == FLEXCAN_ESR_FLT_CONF_PASSIVE))
+		new_state = CAN_STATE_ERROR_PASSIVE;
+	else
+		new_state = CAN_STATE_BUS_OFF;
+
+	/* state hasn't changed */
+	if (likely(new_state == priv->can.state))
+		return 0;
+
+	skb = alloc_can_err_skb(dev, &cf);
+	if (unlikely(!skb))
+		return 0;
+
+	do_state(dev, cf, new_state);
+	priv->can.state = new_state;
+	netif_receive_skb(skb);
+
+	dev->stats.rx_packets++;
+	dev->stats.rx_bytes += cf->can_dlc;
+
+	return 1;
+}
+
+static void flexcan_read_fifo(const struct net_device *dev,
+			      struct can_frame *cf)
+{
+	const struct flexcan_priv *priv = netdev_priv(dev);
+	struct flexcan_regs __iomem *regs = priv->base;
+	struct flexcan_mb __iomem *mb = &regs->cantxfg[0];
+	u32 reg_ctrl, reg_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
+		cf->can_id = (reg_id >> 18) & CAN_SFF_MASK;
+
+	if (reg_ctrl & FLEXCAN_MB_CNT_RTR)
+		cf->can_id |= CAN_RTR_FLAG;
+	cf->can_dlc = get_can_dlc((reg_ctrl >> 16) & 0xf);
+
+	*(__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 */
+	flexcan_write(FLEXCAN_IFLAG_RX_FIFO_AVAILABLE, &regs->iflag1);
+	flexcan_read(&regs->timer);
+}
+
+static int flexcan_read_frame(struct net_device *dev)
+{
+	struct net_device_stats *stats = &dev->stats;
+	struct can_frame *cf;
+	struct sk_buff *skb;
+
+	skb = alloc_can_skb(dev, &cf);
+	if (unlikely(!skb)) {
+		stats->rx_dropped++;
+		return 0;
+	}
+
+	flexcan_read_fifo(dev, cf);
+	netif_receive_skb(skb);
+
+	stats->rx_packets++;
+	stats->rx_bytes += cf->can_dlc;
+
+	return 1;
+}
+
+static int flexcan_poll(struct napi_struct *napi, int quota)
+{
+	struct net_device *dev = napi->dev;
+	const struct flexcan_priv *priv = netdev_priv(dev);
+	struct flexcan_regs __iomem *regs = priv->base;
+	u32 reg_iflag1, reg_esr;
+	int work_done = 0;
+
+	/*
+	 * The error bits are cleared on read,
+	 * use saved value from irq handler.
+	 */
+	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 = flexcan_read(&regs->iflag1);
+	while (reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_AVAILABLE &&
+	       work_done < quota) {
+		work_done += flexcan_read_frame(dev);
+		reg_iflag1 = flexcan_read(&regs->iflag1);
+	}
+
+	/* report bus errors */
+	if (flexcan_has_and_handle_berr(priv, reg_esr) && work_done < quota)
+		work_done += flexcan_poll_bus_err(dev, reg_esr);
+
+	if (work_done < quota) {
+		napi_complete(napi);
+		/* enable IRQs */
+		flexcan_write(FLEXCAN_IFLAG_DEFAULT, &regs->imask1);
+		flexcan_write(priv->reg_ctrl_default, &regs->ctrl);
+	}
+
+	return work_done;
+}
+
+static irqreturn_t flexcan_irq(int irq, void *dev_id)
+{
+	struct net_device *dev = dev_id;
+	struct net_device_stats *stats = &dev->stats;
+	struct flexcan_priv *priv = netdev_priv(dev);
+	struct flexcan_regs __iomem *regs = priv->base;
+	u32 reg_iflag1, reg_esr;
+
+	reg_iflag1 = flexcan_read(&regs->iflag1);
+	reg_esr = flexcan_read(&regs->esr);
+	/* ACK all bus error and state change IRQ sources */
+	if (reg_esr & FLEXCAN_ESR_ALL_INT)
+		flexcan_write(reg_esr & FLEXCAN_ESR_ALL_INT, &regs->esr);
+
+	/*
+	 * schedule NAPI in case of:
+	 * - rx IRQ
+	 * - state change IRQ
+	 * - bus error IRQ and bus error reporting is activated
+	 */
+	if ((reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_AVAILABLE) ||
+	    (reg_esr & FLEXCAN_ESR_ERR_STATE) ||
+	    flexcan_has_and_handle_berr(priv, reg_esr)) {
+		/*
+		 * The error bits are cleared on read,
+		 * save them for later use.
+		 */
+		priv->reg_esr = reg_esr & FLEXCAN_ESR_ERR_BUS;
+		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) {
+		flexcan_write(FLEXCAN_IFLAG_RX_FIFO_OVERFLOW, &regs->iflag1);
+		dev->stats.rx_over_errors++;
+		dev->stats.rx_errors++;
+	}
+
+	/* transmission complete interrupt */
+	if (reg_iflag1 & (1 << FLEXCAN_TX_BUF_ID)) {
+		stats->tx_bytes += can_get_echo_skb(dev, 0);
+		stats->tx_packets++;
+		/* after sending a RTR frame mailbox is in RX mode */
+		flexcan_write(FLEXCAN_MB_CODE_TX_INACTIVE,
+			&regs->cantxfg[FLEXCAN_TX_BUF_ID].can_ctrl);
+		flexcan_write((1 << FLEXCAN_TX_BUF_ID), &regs->iflag1);
+		netif_wake_queue(dev);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static void flexcan_set_bittiming(struct net_device *dev)
+{
+	const struct flexcan_priv *priv = netdev_priv(dev);
+	const struct can_bittiming *bt = &priv->can.bittiming;
+	struct flexcan_regs __iomem *regs = priv->base;
+	u32 reg;
+
+	reg = flexcan_read(&regs->ctrl);
+	reg &= ~(FLEXCAN_CTRL_PRESDIV(0xff) |
+		 FLEXCAN_CTRL_RJW(0x3) |
+		 FLEXCAN_CTRL_PSEG1(0x7) |
+		 FLEXCAN_CTRL_PSEG2(0x7) |
+		 FLEXCAN_CTRL_PROPSEG(0x7) |
+		 FLEXCAN_CTRL_LPB |
+		 FLEXCAN_CTRL_SMP |
+		 FLEXCAN_CTRL_LOM);
+
+	reg |= FLEXCAN_CTRL_PRESDIV(bt->brp - 1) |
+		FLEXCAN_CTRL_PSEG1(bt->phase_seg1 - 1) |
+		FLEXCAN_CTRL_PSEG2(bt->phase_seg2 - 1) |
+		FLEXCAN_CTRL_RJW(bt->sjw - 1) |
+		FLEXCAN_CTRL_PROPSEG(bt->prop_seg - 1);
+
+	if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)
+		reg |= FLEXCAN_CTRL_LPB;
+	if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
+		reg |= FLEXCAN_CTRL_LOM;
+	if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
+		reg |= FLEXCAN_CTRL_SMP;
+
+	netdev_info(dev, "writing ctrl=0x%08x\n", reg);
+	flexcan_write(reg, &regs->ctrl);
+
+	/* print chip status */
+	netdev_dbg(dev, "%s: mcr=0x%08x ctrl=0x%08x\n", __func__,
+		   flexcan_read(&regs->mcr), flexcan_read(&regs->ctrl));
+}
+
+/*
+ * flexcan_chip_start
+ *
+ * this functions is entered with clocks enabled
+ *
+ */
+static int flexcan_chip_start(struct net_device *dev)
+{
+	struct flexcan_priv *priv = netdev_priv(dev);
+	struct flexcan_regs __iomem *regs = priv->base;
+	int err;
+	u32 reg_mcr, reg_ctrl;
+	int i;
+
+	/* enable module */
+	flexcan_chip_enable(priv);
+
+	/* soft reset */
+	flexcan_write(FLEXCAN_MCR_SOFTRST, &regs->mcr);
+	udelay(10);
+
+	reg_mcr = flexcan_read(&regs->mcr);
+	if (reg_mcr & FLEXCAN_MCR_SOFTRST) {
+		netdev_err(dev, "Failed to softreset can module (mcr=0x%08x)\n",
+			   reg_mcr);
+		err = -ENODEV;
+		goto out;
+	}
+
+	flexcan_set_bittiming(dev);
+
+	/*
+	 * MCR
+	 *
+	 * enable freeze
+	 * enable fifo
+	 * halt now
+	 * only supervisor access
+	 * enable warning int
+	 * choose format C
+	 * disable local echo
+	 *
+	 */
+	reg_mcr = flexcan_read(&regs->mcr);
+	reg_mcr &= ~FLEXCAN_MCR_MAXMB(0xff);
+	reg_mcr |= FLEXCAN_MCR_FRZ | FLEXCAN_MCR_FEN | FLEXCAN_MCR_HALT |
+		FLEXCAN_MCR_SUPV | FLEXCAN_MCR_WRN_EN |
+		FLEXCAN_MCR_IDAM_C | FLEXCAN_MCR_SRX_DIS |
+		FLEXCAN_MCR_MAXMB(FLEXCAN_TX_BUF_ID);
+	netdev_dbg(dev, "%s: writing mcr=0x%08x", __func__, reg_mcr);
+	flexcan_write(reg_mcr, &regs->mcr);
+
+	/*
+	 * CTRL
+	 *
+	 * disable timer sync feature
+	 *
+	 * disable auto busoff recovery
+	 * transmit lowest buffer first
+	 *
+	 * enable tx and rx warning interrupt
+	 * enable bus off interrupt
+	 * (== FLEXCAN_CTRL_ERR_STATE)
+	 *
+	 * _note_: we enable the "error interrupt"
+	 * (FLEXCAN_CTRL_ERR_MSK), too. Otherwise we don't get any
+	 * warning or bus passive interrupts.
+	 */
+	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;
+
+	/* save for later use */
+	priv->reg_ctrl_default = reg_ctrl;
+	netdev_dbg(dev, "%s: writing ctrl=0x%08x", __func__, reg_ctrl);
+	flexcan_write(reg_ctrl, &regs->ctrl);
+
+	/* clear and invalidate all mailboxes first */
+	for (i = FLEXCAN_TX_BUF_ID; i < ARRAY_SIZE(regs->cantxfg); i++) {
+		flexcan_write(FLEXCAN_MB_CODE_RX_INACTIVE,
+			      &regs->cantxfg[i].can_ctrl);
+	}
+
+	/* Errata ERR005829: mark first TX mailbox as INACTIVE */
+	flexcan_write(FLEXCAN_MB_CODE_TX_INACTIVE,
+		      &regs->cantxfg[FLEXCAN_TX_BUF_RESERVED].can_ctrl);
+
+	/* mark TX mailbox as INACTIVE */
+	flexcan_write(FLEXCAN_MB_CODE_TX_INACTIVE,
+		      &regs->cantxfg[FLEXCAN_TX_BUF_ID].can_ctrl);
+
+	/* acceptance mask/acceptance code (accept everything) */
+	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 = flexcan_read(&regs->mcr);
+	reg_mcr &= ~FLEXCAN_MCR_HALT;
+	flexcan_write(reg_mcr, &regs->mcr);
+
+	priv->can.state = CAN_STATE_ERROR_ACTIVE;
+
+	/* enable FIFO interrupts */
+	flexcan_write(FLEXCAN_IFLAG_DEFAULT, &regs->imask1);
+
+	/* print chip status */
+	netdev_dbg(dev, "%s: reading mcr=0x%08x ctrl=0x%08x\n", __func__,
+		   flexcan_read(&regs->mcr), flexcan_read(&regs->ctrl));
+
+	return 0;
+
+ out:
+	flexcan_chip_disable(priv);
+	return err;
+}
+
+/*
+ * flexcan_chip_stop
+ *
+ * this functions is entered with clocks enabled
+ *
+ */
+static void flexcan_chip_stop(struct net_device *dev)
+{
+	struct flexcan_priv *priv = netdev_priv(dev);
+	struct flexcan_regs __iomem *regs = priv->base;
+	u32 reg;
+
+	/* Disable all interrupts */
+	flexcan_write(0, &regs->imask1);
+
+	/* Disable + halt module */
+	reg = flexcan_read(&regs->mcr);
+	reg |= FLEXCAN_MCR_MDIS | FLEXCAN_MCR_HALT;
+	flexcan_write(reg, &regs->mcr);
+
+	flexcan_transceiver_switch(priv, 0);
+	priv->can.state = CAN_STATE_STOPPED;
+
+	return;
+}
+
+static int flexcan_open(struct net_device *dev)
+{
+	struct flexcan_priv *priv = netdev_priv(dev);
+	int err;
+
+	clk_prepare_enable(priv->clk);
+
+	err = open_candev(dev);
+	if (err)
+		goto out;
+
+	err = request_irq(dev->irq, flexcan_irq, IRQF_SHARED, dev->name, dev);
+	if (err)
+		goto out_free_irq;
+
+	/* start chip and queuing */
+	err = flexcan_chip_start(dev);
+	if (err)
+		goto out_close;
+	napi_enable(&priv->napi);
+	netif_start_queue(dev);
+
+	return 0;
+
+ out_free_irq:
+	free_irq(dev->irq, dev);
+ out_close:
+	close_candev(dev);
+ out:
+	clk_disable_unprepare(priv->clk);
+
+	return err;
+}
+
+static int flexcan_close(struct net_device *dev)
+{
+	struct flexcan_priv *priv = netdev_priv(dev);
+
+	netif_stop_queue(dev);
+	napi_disable(&priv->napi);
+	flexcan_chip_stop(dev);
+
+	free_irq(dev->irq, dev);
+	clk_disable_unprepare(priv->clk);
+
+	close_candev(dev);
+
+	return 0;
+}
+
+static int flexcan_set_mode(struct net_device *dev, enum can_mode mode)
+{
+	int err;
+
+	switch (mode) {
+	case CAN_MODE_START:
+		err = flexcan_chip_start(dev);
+		if (err)
+			return err;
+
+		netif_wake_queue(dev);
+		break;
+
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	return 0;
+}
+
+static const struct net_device_ops flexcan_netdev_ops = {
+	.ndo_open	= flexcan_open,
+	.ndo_stop	= flexcan_close,
+	.ndo_start_xmit	= flexcan_start_xmit,
+};
+
+static int __devinit register_flexcandev(struct net_device *dev)
+{
+	struct flexcan_priv *priv = netdev_priv(dev);
+	struct flexcan_regs __iomem *regs = priv->base;
+	u32 reg, err;
+
+	clk_prepare_enable(priv->clk);
+
+	/* select "bus clock", chip must be disabled */
+	flexcan_chip_disable(priv);
+	reg = flexcan_read(&regs->ctrl);
+	reg |= FLEXCAN_CTRL_CLK_SRC;
+	flexcan_write(reg, &regs->ctrl);
+
+	flexcan_chip_enable(priv);
+
+	/* set freeze, halt and activate FIFO, restrict register access */
+	reg = flexcan_read(&regs->mcr);
+	reg |= FLEXCAN_MCR_FRZ | FLEXCAN_MCR_HALT |
+		FLEXCAN_MCR_FEN | FLEXCAN_MCR_SUPV;
+	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 = flexcan_read(&regs->mcr);
+	if (!(reg & FLEXCAN_MCR_FEN)) {
+		netdev_err(dev, "Could not enable RX FIFO, unsupported core\n");
+		err = -ENODEV;
+		goto out;
+	}
+
+	err = register_candev(dev);
+
+ out:
+	/* disable core and turn off clocks */
+	flexcan_chip_disable(priv);
+	clk_disable_unprepare(priv->clk);
+
+	return err;
+}
+
+static void __devexit unregister_flexcandev(struct net_device *dev)
+{
+	unregister_candev(dev);
+}
+
+static int __devinit flexcan_probe(struct platform_device *pdev)
+{
+	struct net_device *dev;
+	struct flexcan_priv *priv;
+	struct resource *mem;
+	struct clk *clk = NULL;
+	void __iomem *base;
+	resource_size_t mem_size;
+	int err, irq;
+	u32 clock_freq = 0;
+
+	if (pdev->dev.of_node) {
+		const __be32 *clock_freq_p;
+
+		clock_freq_p = of_get_property(pdev->dev.of_node,
+						"clock-frequency", NULL);
+		if (clock_freq_p)
+			clock_freq = be32_to_cpup(clock_freq_p);
+	}
+
+	if (!clock_freq) {
+		clk = clk_get(&pdev->dev, NULL);
+		if (IS_ERR(clk)) {
+			dev_err(&pdev->dev, "no clock defined\n");
+			err = PTR_ERR(clk);
+			goto failed_clock;
+		}
+		clock_freq = clk_get_rate(clk);
+	}
+
+	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	irq = platform_get_irq(pdev, 0);
+	if (!mem || irq <= 0) {
+		err = -ENODEV;
+		goto failed_get;
+	}
+
+	mem_size = resource_size(mem);
+	if (!request_mem_region(mem->start, mem_size, pdev->name)) {
+		err = -EBUSY;
+		goto failed_get;
+	}
+
+	base = ioremap(mem->start, mem_size);
+	if (!base) {
+		err = -ENOMEM;
+		goto failed_map;
+	}
+
+	dev = alloc_candev(sizeof(struct flexcan_priv), 1);
+	if (!dev) {
+		err = -ENOMEM;
+		goto failed_alloc;
+	}
+
+	dev->netdev_ops = &flexcan_netdev_ops;
+	dev->irq = irq;
+	dev->flags |= IFF_ECHO;
+
+	priv = netdev_priv(dev);
+	priv->can.clock.freq = clock_freq;
+	priv->can.bittiming_const = &flexcan_bittiming_const;
+	priv->can.do_set_mode = flexcan_set_mode;
+	priv->can.do_get_berr_counter = flexcan_get_berr_counter;
+	priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
+		CAN_CTRLMODE_LISTENONLY	| CAN_CTRLMODE_3_SAMPLES |
+		CAN_CTRLMODE_BERR_REPORTING;
+	priv->base = base;
+	priv->dev = dev;
+	priv->clk = clk;
+	priv->pdata = pdev->dev.platform_data;
+
+	netif_napi_add(dev, &priv->napi, flexcan_poll, FLEXCAN_NAPI_WEIGHT);
+
+	dev_set_drvdata(&pdev->dev, dev);
+	SET_NETDEV_DEV(dev, &pdev->dev);
+
+	err = register_flexcandev(dev);
+	if (err) {
+		dev_err(&pdev->dev, "registering netdev failed\n");
+		goto failed_register;
+	}
+
+	dev_info(&pdev->dev, "device registered (reg_base=%p, irq=%d)\n",
+		 priv->base, dev->irq);
+
+	return 0;
+
+ failed_register:
+	free_candev(dev);
+ failed_alloc:
+	iounmap(base);
+ failed_map:
+	release_mem_region(mem->start, mem_size);
+ failed_get:
+	if (clk)
+		clk_put(clk);
+ failed_clock:
+	return err;
+}
+
+static int __devexit flexcan_remove(struct platform_device *pdev)
+{
+	struct net_device *dev = platform_get_drvdata(pdev);
+	struct flexcan_priv *priv = netdev_priv(dev);
+	struct resource *mem;
+
+	unregister_flexcandev(dev);
+	platform_set_drvdata(pdev, NULL);
+	iounmap(priv->base);
+
+	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	release_mem_region(mem->start, resource_size(mem));
+
+	if (priv->clk)
+		clk_put(priv->clk);
+
+	free_candev(dev);
+
+	return 0;
+}
+
+static struct of_device_id flexcan_of_match[] = {
+	{
+		.compatible = "fsl,p1010-flexcan",
+	},
+	{},
+};
+
+static struct platform_driver flexcan_driver = {
+	.driver = {
+		.name = DRV_NAME,
+		.owner = THIS_MODULE,
+		.of_match_table = flexcan_of_match,
+	},
+	.probe = flexcan_probe,
+	.remove = __devexit_p(flexcan_remove),
+};
+
+module_platform_driver(flexcan_driver);
+
+MODULE_AUTHOR("Sascha Hauer <kernel@pengutronix.de>, "
+	      "Marc Kleine-Budde <kernel@pengutronix.de>");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("CAN port driver for flexcan based chip");