Date:	Fri, 16 Jul 2010 15:21:48 +0200
From:	Marc Kleine-Budde <mkl@...gutronix.de>
To:	Wolfgang Grandegger <wg@...ndegger.com>
CC:	socketcan-core@...ts.berlios.de, netdev@...r.kernel.org
Subject: Re: [PATCH] CAN: Add Flexcan CAN controller driver

Wolfgang Grandegger wrote:
> I realized a few issues. You can add my "acked-by" when they are fixed.

thanks for the review.

>>  drivers/net/can/Kconfig              |    6 +
>>  drivers/net/can/Makefile             |    1 +
>>  drivers/net/can/flexcan.c            | 1005 ++++++++++++++++++++++++++++++++++
>>  include/linux/can/platform/flexcan.h |   20 +
>>  4 files changed, 1032 insertions(+), 0 deletions(-)
>>  create mode 100644 drivers/net/can/flexcan.c
>>  create mode 100644 include/linux/can/platform/flexcan.h
>>
>> diff --git a/drivers/net/can/Kconfig b/drivers/net/can/Kconfig
>> index 2c5227c..3f13299 100644
>> --- a/drivers/net/can/Kconfig
>> +++ b/drivers/net/can/Kconfig
>> @@ -73,6 +73,12 @@ config CAN_JANZ_ICAN3
>>  	  This driver can also be built as a module. If so, the module will be
>>  	  called janz-ican3.ko.
>>  
>> +config CAN_FLEXCAN
>> +	tristate "Support for Freescale FLEXCAN based chips"
>> +	depends on CAN_DEV
> 
> Some more arch specific dependencies would be nice.

it's tested on MX25 and MX35, I'll add these.

>> +	---help---
>> +	  Say Y here if you want to support for Freescale FlexCAN.
>> +
>>  source "drivers/net/can/mscan/Kconfig"
>>  
>>  source "drivers/net/can/sja1000/Kconfig"
>> diff --git a/drivers/net/can/Makefile b/drivers/net/can/Makefile
>> index 9047cd0..0057537 100644
>> --- a/drivers/net/can/Makefile
>> +++ b/drivers/net/can/Makefile
>> @@ -16,5 +16,6 @@ obj-$(CONFIG_CAN_TI_HECC)	+= ti_hecc.o
>>  obj-$(CONFIG_CAN_MCP251X)	+= mcp251x.o
>>  obj-$(CONFIG_CAN_BFIN)		+= bfin_can.o
>>  obj-$(CONFIG_CAN_JANZ_ICAN3)	+= janz-ican3.o
>> +obj-$(CONFIG_CAN_FLEXCAN)	+= flexcan.o
>>  
>>  ccflags-$(CONFIG_CAN_DEBUG_DEVICES) := -DDEBUG
>> diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
>> new file mode 100644
>> index 0000000..a3180ba
>> --- /dev/null
>> +++ b/drivers/net/can/flexcan.c
>> @@ -0,0 +1,1005 @@
>> +/*
>> + * 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@...ma-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/platform_device.h>
>> +
>> +
>> +#include <mach/clock.h>
>> +
>> +#define DRV_NAME		"flexcan"
>> +#define FLEXCAN_NAPI_WEIGHT	8
>> +
>> +
>> +/* 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) & 0xf)
>> +#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_TSYNC		BIT(5)
>> +#define FLEXCAN_CTRL_LBUF		BIT(4)
>> +#define FLEXCAN_CTRL_LOM		BIT(3)
>> +#define FLEXCAN_CTRL_PROPSEG(x)		((x) & 0x07)
>> +
>> +/* 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	(0x2 << 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_FRAME \
>> +	(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_LINE \
>> +	(FLEXCAN_ESR_TWRN_INT | FLEXCAN_ESR_RWRN_INT | FLEXCAN_ESR_BOFF_INT)
>> +
>> +/* FLEXCAN interrupt flag register (IFLAG) bits */
>> +#define FLEXCAN_TX_BUF_ID		8
>> +#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_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,
>> +};
>> +
>> +/*
>> + * 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 void flexcan_chip_enable(struct flexcan_priv *priv)
>> +{
>> +	struct flexcan_regs __iomem *regs = priv->base;
>> +	u32 reg;
>> +
>> +	reg = readl(&regs->mcr);
>> +	reg &= ~FLEXCAN_MCR_MDIS;
>> +	writel(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 = readl(&regs->mcr);
>> +	reg |= FLEXCAN_MCR_MDIS;
>> +	writel(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 = readl(&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 net_device_stats *stats = &dev->stats;
>> +	struct flexcan_regs __iomem *regs = priv->base;
>> +	struct can_frame *frame = (struct can_frame *)skb->data;
>> +	u32 can_id;
>> +	u32 ctrl = FLEXCAN_MB_CNT_CODE(0xc) | (frame->can_dlc << 16);
>> +
>> +	if (can_dropped_invalid_skb(dev, skb))
>> +		return NETDEV_TX_OK;
>> +
>> +	netif_stop_queue(dev);
>> +
>> +	if (frame->can_id & CAN_EFF_FLAG) {
>> +		can_id = frame->can_id & CAN_EFF_MASK;
>> +		ctrl |= FLEXCAN_MB_CNT_IDE | FLEXCAN_MB_CNT_SRR;
>> +	} else {
>> +		can_id = (frame->can_id & CAN_SFF_MASK) << 18;
>> +	}
>> +
>> +	if (frame->can_id & CAN_RTR_FLAG)
>> +		ctrl |= FLEXCAN_MB_CNT_RTR;
>> +
>> +	if (frame->can_dlc > 0) {
>> +		u32 data;
>> +		data = frame->data[0] << 24;
>> +		data |= frame->data[1] << 16;
>> +		data |= frame->data[2] << 8;
>> +		data |= frame->data[3];
>> +		writel(data, &regs->cantxfg[FLEXCAN_TX_BUF_ID].data[0]);
>> +	}
> 
> IIRC, in your review of Jürgens patch you suggested to use be32_to_cpu here.

ACK, will change these

>> +	if (frame->can_dlc > 3) {
>> +		u32 data;
>> +		data = frame->data[4] << 24;
>> +		data |= frame->data[5] << 16;
>> +		data |= frame->data[6] << 8;
>> +		data |= frame->data[7];
>> +		writel(data, &regs->cantxfg[FLEXCAN_TX_BUF_ID].data[1]);
>> +	}
> 
> Ditto.

ACK

>> +	writel(can_id, &regs->cantxfg[FLEXCAN_TX_BUF_ID].can_id);
>> +	writel(ctrl, &regs->cantxfg[FLEXCAN_TX_BUF_ID].can_ctrl);
>> +
>> +	kfree_skb(skb);
>> +
>> +	stats->tx_bytes += frame->can_dlc;
>> +
>> +	return NETDEV_TX_OK;
>> +}
>> +
>> +
>> +static void flexcan_poll_err_frame(struct net_device *dev,
>> +				   struct can_frame *cf, u32 reg_esr)
>> +{
>> +	struct flexcan_priv *priv = netdev_priv(dev);
>> +	int error_warning = 0, rx_errors = 0, tx_errors = 0;
>> +
>> +	if (reg_esr & FLEXCAN_ESR_BIT1_ERR) {
>> +		rx_errors = 1;
>> +		cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
>> +		cf->data[2] |= CAN_ERR_PROT_BIT1;
>> +	}
>> +
>> +	if (reg_esr & FLEXCAN_ESR_BIT0_ERR) {
>> +		rx_errors = 1;
>> +		cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
>> +		cf->data[2] |= CAN_ERR_PROT_BIT0;
>> +	}
>> +
>> +	if (reg_esr & FLEXCAN_ESR_FRM_ERR) {
>> +		rx_errors = 1;
>> +		cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
>> +		cf->data[2] |= CAN_ERR_PROT_FORM;
>> +	}
>> +
>> +	if (reg_esr & FLEXCAN_ESR_STF_ERR) {
>> +		rx_errors = 1;
>> +		cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
>> +		cf->data[2] |= CAN_ERR_PROT_STUFF;
>> +	}
>> +
>> +
>> +	if (reg_esr & FLEXCAN_ESR_ACK_ERR) {
>> +		tx_errors = 1;
>> +		cf->can_id |= CAN_ERR_ACK;
> 
> This is a bus-error as well. Therefore I think it should be:
> 
> 	if (reg_esr & FLEXCAN_ESR_ACK_ERR) {
> 		tx_errors = 1;
> 		cf->can_id |= CAN_ERR_ACK;
> 		cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
> 		cf->data[3] |= CAN_ERR_PROT_LOC_ACK; /* ACK slot */
> 	}
> 
> I need to check what CAN_ERR_ACK is intended for. Then, cf->can_id could
> be preset with "CAN_ERR_PROT | CAN_ERR_BUSERROR" at the beginning.
> 
>> +	}
>> +
>> +	if (error_warning)
>> +		priv->can.can_stats.error_warning++;
> 
> Hm, error_warning is always 0 !?

this must go into the state handling function, will fix.
> 
>> +	if (rx_errors)
>> +		dev->stats.rx_errors++;
>> +	if (tx_errors)
>> +		dev->stats.tx_errors++;
>> +
>> +}
>> +
>> +static void flexcan_poll_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;
>> +
>> +	flexcan_poll_err_frame(dev, cf, reg_esr);
>> +	netif_receive_skb(skb);
>> +
>> +	dev->stats.rx_packets++;
>> +	dev->stats.rx_bytes += cf->can_dlc;
>> +}
>> +
>> +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 = readl(&mb->can_ctrl);
>> +	reg_id = readl(&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(readl(&mb->data[0]));
>> +	*(__be32 *)(cf->data + 4) = cpu_to_be32(readl(&mb->data[1]));
>> +
>> +	/* mark as read */
>> +	writel(FLEXCAN_IFLAG_RX_FIFO_AVAILABLE, &regs->iflag1);
>> +	readl(&regs->timer);
>> +}
>> +
>> +static void 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;
>> +	}
>> +
>> +	flexcan_read_fifo(dev, cf);
>> +	netif_receive_skb(skb);
>> +
>> +	stats->rx_packets++;
>> +	stats->rx_bytes += cf->can_dlc;
>> +}
>> +
>> +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;
>> +
>> +	reg_iflag1 = readl(&regs->iflag1);
>> +
>> +	/* first handle RX-FIFO */
>> +	while (reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_AVAILABLE &&
>> +	       work_done < quota) {
>> +		flexcan_read_frame(dev);
>> +
>> +		work_done++;
>> +		reg_iflag1 = readl(&regs->iflag1);
>> +	}
>> +
>> +	/*
>> +	 * The error bits are clear on read,
>> +	 * so use saved value from irq handler.
>> +	 */
>> +	reg_esr = readl(&regs->esr) | priv->reg_esr;
> 
> Re-reading reg_esr may cause lost of state changes.

To my understanding of the datasheet and my observation, only the error
bits are cleared on read. The bit defining the status
(FLEXCAN_ESR_FLT_CONF_MASK) == error active, error passive and bus off
are not cleared on read.

However there are two bits defining RX and TX warning level, I'll check
these.

>> +	if (work_done < quota) {
>> +		flexcan_poll_err(dev, reg_esr);
> 
> An error frame is created here for each call of flexcan_poll(), not only
> in case of errors.

Doh, will fix this.

> 
>> +		work_done++;
>> +	}
>> +
>> +	if (work_done < quota) {
>> +		napi_complete(napi);
>> +		/* enable IRQs */
>> +		writel(FLEXCAN_IFLAG_DEFAULT, &regs->imask1);
>> +		writel(priv->reg_ctrl_default, &regs->ctrl);
>> +	}
>> +
>> +	return work_done;
>> +}
>> +
>> +static void flexcan_irq_err_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) {
>> +			dev_dbg(dev->dev.parent, "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) {
>> +			dev_dbg(dev->dev.parent, "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:
>> +		dev_err(dev->dev.parent,
>> +			"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_BUS_OFF:
>> +		cf->can_id |= CAN_ERR_BUSOFF;
>> +		can_bus_off(dev);
>> +		break;
>> +	default:
>> +		break;
>> +	}
>> +}
>> +
>> +static void flexcan_irq_err(struct net_device *dev)
>> +{
>> +	struct flexcan_priv *priv = netdev_priv(dev);
>> +	struct flexcan_regs __iomem *regs = priv->base;
>> +	struct sk_buff *skb;
>> +	struct can_frame *cf;
>> +	enum can_state new_state;
>> +	u32 reg_esr;
>> +	int flt;
>> +
>> +	reg_esr = readl(&regs->esr);
> 
> As discussed, reg_esr is re-read here. Should probably be passed via
> function argument.

ACK

> 
>> +	writel(reg_esr, &regs->esr);
>> +
>> +	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;
>> +
>> +	skb = alloc_can_err_skb(dev, &cf);
>> +	if (unlikely(!skb))
>> +		return;
>> +
>> +	flexcan_irq_err_state(dev, cf, new_state);
>> +	netif_rx(skb);
>> +
>> +	dev->stats.rx_packets++;
>> +	dev->stats.rx_bytes += cf->can_dlc;
>> +
>> +	priv->can.state = new_state;
>> +}
>> +
>> +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 = readl(&regs->iflag1);
>> +	reg_esr = readl(&regs->esr);
>> +
>> +	/* receive or error interrupt -> napi */
>> +	if ((reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_AVAILABLE) ||
>> +	    (reg_esr & FLEXCAN_ESR_ERR_FRAME)) {
>> +		/*
>> +		 * The error bits are cleared on read,
>> +		 * save for later use.
>> +		 */
>> +		priv->reg_esr = reg_esr;
>> +		writel(FLEXCAN_IFLAG_DEFAULT & ~FLEXCAN_IFLAG_RX_FIFO_AVAILABLE,
>> +		       &regs->imask1);
>> +		writel(priv->reg_ctrl_default & ~FLEXCAN_CTRL_ERR_MSK,
>> +		       &regs->ctrl);
>> +		napi_schedule(&priv->napi);
>> +	}
>> +
>> +	/* FIFO overflow */
>> +	if (reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_OVERFLOW) {
>> +		writel(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_packets++;
> 
> Where is stats->tx_bytes incremented?

At the end of flexcan_start_xmit(), here the skb is already freed.

>> +		writel((1 << FLEXCAN_TX_BUF_ID), &regs->iflag1);
>> +		netif_wake_queue(dev);
>> +	}
>> +
>> +	/* handle state changes */
>> +	flexcan_irq_err(dev);
> 
> This does create and send an error message for *each* interrupt, even
> for non-error interrupts (RX and TX).

No, have a look at flexcan_irq_err(), first it will determine the
current state of the can controller and only if the state changes it
will send an error message.

> Also, state changes are handled in the hard-irq context, while the
> errors are handle in the soft-irq context. This looks tricky and error
> prune to me as both are derived from the esr register. State changes and
> errors might not be realized in the correct order, etc. It might be
> saver to handle both in the poll routine by a common function.

okay, will do.

>> +
>> +	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 = readl(&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;
>> +
>> +	dev_info(dev->dev.parent, "writing ctrl=0x%08x\n", reg);
>> +	writel(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));
> 
> This seems especially useful for development. Please check the other
> dev_dbg's as well.

They are quite good for debugging, too. Hence the "dev_dbg" :)
The stati are just printed during initialisation.

> 
>> +}
>> +
>> +/*
>> + * 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;
>> +	unsigned int i;
>> +	int err;
>> +	u32 reg_mcr, reg_ctrl;
>> +
>> +	/* enable module */
>> +	flexcan_chip_enable(priv);
>> +
>> +	/* soft reset */
>> +	writel(FLEXCAN_MCR_SOFTRST, &regs->mcr);
>> +	udelay(10);
>> +
>> +	reg_mcr = readl(&regs->mcr);
>> +	if (reg_mcr & FLEXCAN_MCR_SOFTRST) {
>> +		dev_err(dev->dev.parent,
>> +			"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
>> +	 *
>> +	 */
>> +	reg_mcr = readl(&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);
>> +
>> +	/*
>> +	 * CTRL
>> +	 *
>> +	 * enable bus off interrupt
>> +	 * disable auto busoff recovery
>> +	 * enable tx and rx warning interrupt
>> +	 * transmit lowest buffer first
>> +	 */
>> +	reg_ctrl = readl(&regs->ctrl);
>> +	reg_ctrl |= FLEXCAN_CTRL_BOFF_MSK |FLEXCAN_CTRL_BOFF_REC |
>> +		FLEXCAN_CTRL_TWRN_MSK | FLEXCAN_CTRL_RWRN_MSK |
>> +		FLEXCAN_CTRL_LBUF;
>> +	/*
>> +	 * TODO: for now turn on the error interrupt, otherwise we
>> +	 * don't get any warning or bus passive interrupts.
>> +	 */
>> +	reg_ctrl |= FLEXCAN_CTRL_ERR_MSK;
>> +
>> +	/* 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);
>> +
>> +	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]);
>> +
>> +		/* put MB into rx queue */
>> +		writel(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_transceiver_switch(priv, 1);
>> +
>> +	/* synchronize with the can bus */
>> +	reg_mcr = readl(&regs->mcr);
>> +	reg_mcr &= ~FLEXCAN_MCR_HALT;
>> +	writel(reg_mcr, &regs->mcr);
>> +
>> +	priv->can.state = CAN_STATE_ERROR_ACTIVE;
>> +
>> +	/* enable FIFO interrupts */
>> +	writel(FLEXCAN_IFLAG_DEFAULT, &regs->imask1);
>> +
>> +	/* print chip status */
>> +	dev_dbg(dev->dev.parent, "%s: mcr=0x%08x ctrl=0x%08x\n", __func__,
>> +		readl(&regs->mcr), readl(&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 */
>> +	writel(0, &regs->imask1);
>> +
>> +	/* Disable + halt module */
>> +	reg = readl(&regs->mcr);
>> +	reg |= FLEXCAN_MCR_MDIS | FLEXCAN_MCR_HALT;
>> +	writel(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_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_close;
>> +
>> +	/* 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_close:
>> +	close_candev(dev);
>> + out:
>> +	clk_disable(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(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_enable(priv->clk);
>> +
>> +	/* select "bus clock", chip must be disabled */
>> +	flexcan_chip_disable(priv);
>> +	reg = readl(&regs->ctrl);
>> +	reg |= FLEXCAN_CTRL_CLK_SRC;
>> +	writel(reg, &regs->ctrl);
>> +
>> +	flexcan_chip_enable(priv);
>> +
>> +	/* set freeze, halt and activate FIFO, restrict register access */
>> +	reg = readl(&regs->mcr);
>> +	reg |= FLEXCAN_MCR_FRZ | FLEXCAN_MCR_HALT |
>> +		FLEXCAN_MCR_FEN | FLEXCAN_MCR_SUPV;
>> +	writel(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);
>> +	if (!(reg & FLEXCAN_MCR_FEN)) {
>> +		dev_err(dev->dev.parent,
>> +			"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(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;
>> +	void __iomem *base;
>> +	resource_size_t mem_size;
>> +	int err, irq;
>> +
>> +	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;
>> +	}
>> +
>> +	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_req;
>> +	}
>> +
>> +	base = ioremap(mem->start, mem_size);
>> +	if (!base) {
>> +		err = -ENOMEM;
>> +		goto failed_map;
>> +	}
>> +
>> +	dev = alloc_candev(sizeof(struct flexcan_priv), 0);
>> +	if (!dev) {
>> +		err = -ENOMEM;
>> +		goto failed_alloc;
>> +	}
>> +
>> +	dev->netdev_ops = &flexcan_netdev_ops;
>> +	dev->irq = irq;
>> +	dev->flags |= IFF_ECHO; /* we support local echo in hardware */
>> +
>> +	priv = netdev_priv(dev);
>> +	priv->can.clock.freq = clk_get_rate(clk);
>> +	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;
>> +	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_req:
>> +	clk_put(clk);
>> + failed_get:
>> + 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);
>> +	free_candev(dev);
>> +	iounmap(priv->base);
>> +
>> +	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> +	release_mem_region(mem->start, resource_size(mem));
>> +
>> +	clk_put(priv->clk);
>> +
>> +	return 0;
>> +}
>> +
>> +static struct platform_driver flexcan_driver = {
>> +	.driver.name = DRV_NAME,
>> +	.probe = flexcan_probe,
>> +	.remove = __devexit_p(flexcan_remove),
>> +};
>> +
>> +static int __init flexcan_init(void)
>> +{
>> +	pr_info("%s netdevice driver\n", DRV_NAME);
>> +	return platform_driver_register(&flexcan_driver);
>> +}
>> +
>> +static void __exit flexcan_exit(void)
>> +{
>> +	platform_driver_unregister(&flexcan_driver);
>> +	pr_info("%s: driver removed\n", DRV_NAME);
>> +}
>> +
>> +module_init(flexcan_init);
>> +module_exit(flexcan_exit);
>> +
>> +MODULE_AUTHOR("Sascha Hauer <kernel@...gutronix.de>, "
>> +	      "Marc Kleine-Budde <kernel@...gutronix.de>");
>> +MODULE_LICENSE("GPL v2");
>> +MODULE_DESCRIPTION("CAN port driver for flexcan based chip");
>> diff --git a/include/linux/can/platform/flexcan.h b/include/linux/can/platform/flexcan.h
>> new file mode 100644
>> index 0000000..72b713a
>> --- /dev/null
>> +++ b/include/linux/can/platform/flexcan.h
>> @@ -0,0 +1,20 @@
>> +/*
>> + * Copyright (C) 2010 Marc Kleine-Budde <kernel@...gutronix.de>
>> + *
>> + * This file is released under the GPLv2
>> + *
>> + */
>> +
>> +#ifndef __CAN_PLATFORM_FLEXCAN_H
>> +#define __CAN_PLATFORM_FLEXCAN_H
>> +
>> +/**
>> + * struct flexcan_platform_data - flex CAN controller platform data
>> + * @transceiver_enable:         - called to power on/off the transceiver
>> + *
>> + */
>> +struct flexcan_platform_data {
>> +	void (*transceiver_switch)(int enable);
>> +};
>> +
>> +#endif /* __CAN_PLATFORM_FLEXCAN_H */
> 
> Wolfgang.

cheers, Marc
-- 
Pengutronix e.K.                  | Marc Kleine-Budde           |
Industrial Linux Solutions        | Phone: +49-231-2826-924     |
Vertretung West/Dortmund          | Fax:   +49-5121-206917-5555 |
Amtsgericht Hildesheim, HRA 2686  | http://www.pengutronix.de   |



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