On 01/11/2011 12:49 PM, Bhupesh Sharma wrote:
> Bosch C_CAN controller is a full-CAN implementation which is compliant
> to CAN protocol version 2.0 part A and B. Bosch C_CAN user manual can be
> obtained from:
> http://www.semiconductors.bosch.de/media/en/pdf/ipmodules_1/
> c_can/users_manual_c_can.pdf
> 
> This patch adds the support for this controller.
> The following are the design choices made while writing the controller
> driver:
> 1. Interface Register set IF1 has be used only in the current design.
> 2. Out of the 32 Message objects available, 16 are kept aside for RX
>    purposes and the rest for TX purposes.
> 3. NAPI implementation is such that both the TX and RX paths function
>    in polling mode.

Can you replace all "dev_<LEVEL>(dev->dev.parent," by
"netdev_<LEVEL>(dev,".

> 
> Changes since V3:
> 1. Corrected commenting style.
> 2. Removing *non-required* header files from driver files.
> 3. Removed extra *non-required* outer brackets globally.
> 4. Implemented and used a inline routine to check BUSY status.
> 5. Added a board-specific param *priv* inside the c_can_priv struct.

The changes are usually placed between the "---" and the diffstat, so
that they don't show up in the commit message in the git repo.

> 
> Signed-off-by: Bhupesh Sharma <[email protected]>
> ---
>  drivers/net/can/Kconfig                |    2 +
>  drivers/net/can/Makefile               |    1 +
>  drivers/net/can/c_can/Kconfig          |   15 +
>  drivers/net/can/c_can/Makefile         |    8 +
>  drivers/net/can/c_can/c_can.c          |  953 
> ++++++++++++++++++++++++++++++++
>  drivers/net/can/c_can/c_can.h          |  235 ++++++++
>  drivers/net/can/c_can/c_can_platform.c |  208 +++++++
>  7 files changed, 1422 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/net/can/c_can/Kconfig
>  create mode 100644 drivers/net/can/c_can/Makefile
>  create mode 100644 drivers/net/can/c_can/c_can.c
>  create mode 100644 drivers/net/can/c_can/c_can.h
>  create mode 100644 drivers/net/can/c_can/c_can_platform.c
> 
> diff --git a/drivers/net/can/Kconfig b/drivers/net/can/Kconfig
> index 9d9e453..50549b5 100644
> --- a/drivers/net/can/Kconfig
> +++ b/drivers/net/can/Kconfig
> @@ -86,6 +86,8 @@ source "drivers/net/can/mscan/Kconfig"
>  
>  source "drivers/net/can/sja1000/Kconfig"
>  
> +source "drivers/net/can/c_can/Kconfig"
> +
>  source "drivers/net/can/usb/Kconfig"
>  
>  config CAN_DEBUG_DEVICES
> diff --git a/drivers/net/can/Makefile b/drivers/net/can/Makefile
> index 0057537..c3efeb3 100644
> --- a/drivers/net/can/Makefile
> +++ b/drivers/net/can/Makefile
> @@ -11,6 +11,7 @@ obj-y                               += usb/
>  
>  obj-$(CONFIG_CAN_SJA1000)    += sja1000/
>  obj-$(CONFIG_CAN_MSCAN)              += mscan/
> +obj-$(CONFIG_CAN_C_CAN)              += c_can/
>  obj-$(CONFIG_CAN_AT91)               += at91_can.o
>  obj-$(CONFIG_CAN_TI_HECC)    += ti_hecc.o
>  obj-$(CONFIG_CAN_MCP251X)    += mcp251x.o
> diff --git a/drivers/net/can/c_can/Kconfig b/drivers/net/can/c_can/Kconfig
> new file mode 100644
> index 0000000..ffb9773
> --- /dev/null
> +++ b/drivers/net/can/c_can/Kconfig
> @@ -0,0 +1,15 @@
> +menuconfig CAN_C_CAN
> +     tristate "Bosch C_CAN devices"
> +     depends on CAN_DEV && HAS_IOMEM
> +
> +if CAN_C_CAN
> +
> +config CAN_C_CAN_PLATFORM
> +     tristate "Generic Platform Bus based C_CAN driver"
> +     ---help---
> +       This driver adds support for the C_CAN chips connected to
> +       the "platform bus" (Linux abstraction for directly to the
> +       processor attached devices) which can be found on various
> +       boards from ST Microelectronics (http://www.st.com)
> +       like the SPEAr1310 and SPEAr320 evaluation boards.
> +endif
> diff --git a/drivers/net/can/c_can/Makefile b/drivers/net/can/c_can/Makefile
> new file mode 100644
> index 0000000..9273f6d
> --- /dev/null
> +++ b/drivers/net/can/c_can/Makefile
> @@ -0,0 +1,8 @@
> +#
> +#  Makefile for the Bosch C_CAN controller drivers.
> +#
> +
> +obj-$(CONFIG_CAN_C_CAN) += c_can.o
> +obj-$(CONFIG_CAN_C_CAN_PLATFORM) += c_can_platform.o
> +
> +ccflags-$(CONFIG_CAN_DEBUG_DEVICES) := -DDEBUG
> diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c
> new file mode 100644
> index 0000000..06e1553
> --- /dev/null
> +++ b/drivers/net/can/c_can/c_can.c
> @@ -0,0 +1,953 @@
> +/*
> + * CAN bus driver for Bosch C_CAN controller
> + *
> + * Copyright (C) 2010 ST Microelectronics
> + * Bhupesh Sharma <[email protected]>
> + *
> + * Borrowed heavily from the C_CAN driver originally written by:
> + * Copyright (C) 2007
> + * - Sascha Hauer, Marc Kleine-Budde, Pengutronix <[email protected]>
> + * - Simon Kallweit, intefo AG <[email protected]>
> + *
> + * TX and RX NAPI implementation has been borrowed from at91 CAN driver
> + * written by:

I've just cleaned up the RX implementation, have a look at [1] and [2].

> + * Copyright
> + * (C) 2007 by Hans J. Koch <[email protected]>
                               ^^^^^^^^^^^^^^^^^^^

Hans has recently changed his email address, it's "[email protected]"

> + * (C) 2008, 2009 by Marc Kleine-Budde <[email protected]>
> + *
> + * Bosch C_CAN controller is compliant to CAN protocol version 2.0 part A 
> and B.
> + * Bosch C_CAN user manual can be obtained from:
> + * http://www.semiconductors.bosch.de/media/en/pdf/ipmodules_1/c_can/
> + * users_manual_c_can.pdf
> + *
> + * This file is licensed under the terms of the GNU General Public
> + * License version 2. This program is licensed "as is" without any
> + * warranty of any kind, whether express or implied.
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/version.h>
> +#include <linux/module.h>
> +#include <linux/interrupt.h>
> +#include <linux/delay.h>
> +#include <linux/netdevice.h>
> +#include <linux/if_arp.h>
> +#include <linux/if_ether.h>
> +#include <linux/list.h>
> +#include <linux/delay.h>
> +#include <linux/io.h>
> +
> +#include <linux/can.h>
> +#include <linux/can/dev.h>
> +#include <linux/can/error.h>
> +
> +#include "c_can.h"
> +
> +static struct can_bittiming_const c_can_bittiming_const = {
> +     .name = KBUILD_MODNAME,
> +     .tseg1_min = 2,         /* Time segment 1 = prop_seg + phase_seg1 */
> +     .tseg1_max = 16,
> +     .tseg2_min = 1,         /* Time segment 2 = phase_seg2 */
> +     .tseg2_max = 8,
> +     .sjw_max = 4,
> +     .brp_min = 1,
> +     .brp_max = 1024,        /* 6-bit BRP field + 4-bit BRPE field*/
> +     .brp_inc = 1,
> +};
> +
> +static inline int get_tx_next_msg_obj(const struct c_can_priv *priv)
> +{
> +     return (priv->tx_next & C_CAN_NEXT_MSG_OBJ_MASK) +
> +                     C_CAN_MSG_OBJ_TX_FIRST;
> +}
> +
> +static inline int get_tx_echo_msg_obj(const struct c_can_priv *priv)
> +{
> +     return (priv->tx_echo & C_CAN_NEXT_MSG_OBJ_MASK) +
> +                     C_CAN_MSG_OBJ_TX_FIRST;
> +}
> +
> +static u32 c_can_read_reg32(struct c_can_priv *priv, void *reg)
> +{
> +     u32 val = priv->read_reg(priv, reg);
> +     val |= ((u32) priv->read_reg(priv, reg + 2)) << 16;
> +     return val;
> +}
> +
> +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);
> +
> +     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);
> +}
> +
> +static inline int c_can_check_busy_status(struct c_can_priv *priv, int iface)
> +{
> +     int count = MIN_TIMEOUT_VALUE;

I'd insert a blank line, here.

> +     while (count && priv->read_reg(priv,
> +                             &priv->regs->intf[iface].com_reg) &
> +                             IF_COMR_BUSY) {
> +             count--;
> +             udelay(1);
> +     }
> +
> +     return count;
> +}
> +
> +static inline void c_can_object_get(struct net_device *dev,
> +                                     int iface, int objno, int mask)
> +{
> +     int ret;
> +     struct c_can_priv *priv = netdev_priv(dev);
> +
> +     /*
> +      * As per specs, after writting the message object number in the
> +      * IF command request register the transfer b/w interface
> +      * register and message RAM must be complete in 6 CAN-CLK
> +      * period.
> +      */
> +
> +     priv->write_reg(priv, &priv->regs->intf[iface].com_mask,
> +                     IFX_WRITE_LOW_16BIT(mask));
> +     priv->write_reg(priv, &priv->regs->intf[iface].com_reg,
> +                     IFX_WRITE_LOW_16BIT(objno + 1));
> +
> +     ret = c_can_check_busy_status(priv, iface);
> +     if (!ret)
> +             dev_err(dev->dev.parent, "timed out in object get\n");
> +}
> +
> +static inline void c_can_object_put(struct net_device *dev,
> +                                     int iface, int objno, int mask)
> +{
> +     int ret;
> +     struct c_can_priv *priv = netdev_priv(dev);
> +
> +     /*
> +      * As per specs, after writting the message object number in the
> +      * IF command request register the transfer b/w interface
> +      * register and message RAM must be complete in 6 CAN-CLK
> +      * period.
> +      */
> +
> +     priv->write_reg(priv, &priv->regs->intf[iface].com_mask,
> +                     (IF_COMM_WR | IFX_WRITE_LOW_16BIT(mask)));
> +     priv->write_reg(priv, &priv->regs->intf[iface].com_reg,
> +                     IFX_WRITE_LOW_16BIT(objno + 1));
> +
> +     ret = c_can_check_busy_status(priv, iface);
> +     if (!ret)
> +             dev_err(dev->dev.parent, "timed out in object put\n");
> +}
> +
> +int c_can_write_msg_object(struct net_device *dev,
> +                     int iface, struct can_frame *frame, int objno)
> +{
> +     int i;
> +     u16 flags = 0;
> +     unsigned int id;
> +     struct c_can_priv *priv = netdev_priv(dev);
> +
> +     if (!(frame->can_id & CAN_RTR_FLAG))
> +             flags |= IF_ARB_TRANSMIT;
> +
> +     if (frame->can_id & CAN_EFF_FLAG) {
> +             id = frame->can_id & CAN_EFF_MASK;
> +             flags |= IF_ARB_MSGXTD;
> +     } else
> +             id = ((frame->can_id & CAN_SFF_MASK) << 18);
> +
> +     flags |= IF_ARB_MSGVAL;
> +
> +     priv->write_reg(priv, &priv->regs->intf[iface].arb1,
> +                             IFX_WRITE_LOW_16BIT(id));
> +     priv->write_reg(priv, &priv->regs->intf[iface].arb2, flags |
> +                             IFX_WRITE_HIGH_16BIT(id));
> +
> +     for (i = 0; i < frame->can_dlc; i += 2) {
> +             priv->write_reg(priv, &priv->regs->intf[iface].data[i / 2],
> +                             frame->data[i] | (frame->data[i + 1] << 8));
> +     }
> +
> +     return frame->can_dlc;
> +}
> +
> +static inline void c_can_mark_rx_msg_obj(struct net_device *dev,
> +                                             int iface, int ctrl_mask,
> +                                             int obj)
> +{
> +     struct c_can_priv *priv = netdev_priv(dev);
> +
> +     priv->write_reg(priv, &priv->regs->intf[iface].msg_cntrl,
> +                     ctrl_mask & ~(IF_MCONT_MSGLST | IF_MCONT_INTPND));
> +     c_can_object_put(dev, iface, obj, IF_COMM_CONTROL);
> +
> +}
> +
> +static inline void c_can_activate_all_lower_rx_msg_obj(struct net_device 
> *dev,
> +                                             int iface,
> +                                             int ctrl_mask)
> +{
> +     int i;
> +     struct c_can_priv *priv = netdev_priv(dev);
> +
> +     for (i = 0; i < C_CAN_MSG_RX_LOW_LAST; i++) {
> +             priv->write_reg(priv, &priv->regs->intf[iface].msg_cntrl,
> +                             ctrl_mask & ~(IF_MCONT_MSGLST |
> +                                     IF_MCONT_INTPND | IF_MCONT_NEWDAT));
> +             c_can_object_put(dev, iface, i + 1, IF_COMM_CONTROL);
> +     }
> +}
> +
> +static inline void c_can_activate_rx_msg_obj(struct net_device *dev,
> +                                             int iface, int ctrl_mask,
> +                                             int obj)
> +{
> +     struct c_can_priv *priv = netdev_priv(dev);
> +
> +     priv->write_reg(priv, &priv->regs->intf[iface].msg_cntrl,
> +                     ctrl_mask & ~(IF_MCONT_MSGLST |
> +                             IF_MCONT_INTPND | IF_MCONT_NEWDAT));
> +     c_can_object_put(dev, iface, obj, IF_COMM_CONTROL);
> +
> +}
> +
> +static void c_can_handle_lost_msg_obj(struct net_device *dev,
> +                                     int iface, int objno)
> +{
> +     struct c_can_priv *priv = netdev_priv(dev);
> +     struct net_device_stats *stats = &dev->stats;
> +     struct sk_buff *skb;
> +     struct can_frame *frame;
> +
> +     dev_err(dev->dev.parent, "msg lost in buffer %d\n", objno);
> +
> +     c_can_object_get(dev, iface, objno, IF_COMM_ALL &
> +                                             ~IF_COMM_TXRQST);
> +
> +     priv->write_reg(priv, &priv->regs->intf[iface].msg_cntrl,
> +                     IF_MCONT_CLR_MSGLST);
> +
> +     c_can_object_put(dev, 0, objno, IF_COMM_CONTROL);
> +
> +     /* create an error msg */
> +     skb = alloc_can_err_skb(dev, &frame);
> +     if (unlikely(!skb))
> +             return;
> +
> +     frame->can_id |= CAN_ERR_CRTL;
> +     frame->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
> +     stats->rx_errors++;
> +     stats->rx_over_errors++;
> +
> +     netif_receive_skb(skb);
> +}
> +
> +static int c_can_read_msg_object(struct net_device *dev, int iface, int ctrl,
> +                             int objno)
> +{
> +     u16 flags, data;
> +     int i;
> +     unsigned int val;
> +     struct c_can_priv *priv = netdev_priv(dev);
> +     struct net_device_stats *stats = &dev->stats;
> +     struct sk_buff *skb;
> +     struct can_frame *frame;
> +
> +     skb = alloc_can_skb(dev, &frame);
> +     if (!skb) {
> +             stats->rx_dropped++;
> +             return -ENOMEM;
> +     }
> +
> +     frame->can_dlc = get_can_dlc(ctrl & 0x0F);
> +
> +     for (i = 0; i < frame->can_dlc; i += 2) {
> +             data = priv->read_reg(priv,
> +                             &priv->regs->intf[iface].data[i / 2]);
> +             frame->data[i] = data;
> +             frame->data[i + 1] = data >> 8;
> +     }
> +
> +     flags = priv->read_reg(priv, &priv->regs->intf[iface].arb2);
> +     val = priv->read_reg(priv, &priv->regs->intf[iface].arb1) |
> +             (flags << 16);
> +
> +     if (flags & IF_ARB_MSGXTD)
> +             frame->can_id = (val & CAN_EFF_MASK) | CAN_EFF_FLAG;
> +     else
> +             frame->can_id = (val >> 18) & CAN_SFF_MASK;
> +
> +     if (flags & IF_ARB_TRANSMIT)
> +             frame->can_id |= CAN_RTR_FLAG;
> +
> +     netif_receive_skb(skb);
> +
> +     stats->rx_packets++;
> +     stats->rx_bytes += frame->can_dlc;
> +
> +     return 0;
> +}
> +
> +static void c_can_setup_receive_object(struct net_device *dev, int iface,
> +                                     int objno, unsigned int mask,
> +                                     unsigned int id, unsigned int mcont)
> +{
> +     struct c_can_priv *priv = netdev_priv(dev);
> +
> +     priv->write_reg(priv, &priv->regs->intf[iface].mask1,
> +                     IFX_WRITE_LOW_16BIT(mask));
> +     priv->write_reg(priv, &priv->regs->intf[iface].mask2,
> +                     IFX_WRITE_HIGH_16BIT(mask));
> +
> +     priv->write_reg(priv, &priv->regs->intf[iface].arb1,
> +                     IFX_WRITE_LOW_16BIT(id));
> +     priv->write_reg(priv, &priv->regs->intf[iface].arb2,
> +                     (IF_ARB_MSGVAL | IFX_WRITE_HIGH_16BIT(id)));
> +
> +     priv->write_reg(priv, &priv->regs->intf[iface].msg_cntrl, mcont);
> +     c_can_object_put(dev, iface, objno, IF_COMM_ALL & ~IF_COMM_TXRQST);
> +     dev_dbg(dev->dev.parent, "obj no:%d, msgval:0x%08x\n", objno,
> +                     c_can_read_reg32(priv, &priv->regs->msgval1));
> +
> +}
> +
> +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->intf[iface].arb1, 0);
> +     priv->write_reg(priv, &priv->regs->intf[iface].arb2, 0);
> +     priv->write_reg(priv, &priv->regs->intf[iface].msg_cntrl, 0);
> +
> +     c_can_object_put(dev, iface, objno,
> +                             IF_COMM_ARB | IF_COMM_CONTROL);
> +     dev_dbg(dev->dev.parent, "obj no:%d, msgval:0x%08x\n", objno,
> +                     c_can_read_reg32(priv, &priv->regs->msgval1));
> +
> +}
> +
> +static netdev_tx_t c_can_start_xmit(struct sk_buff *skb,
> +                                     struct net_device *dev)
> +{
> +     u32 val;
> +     u32 msg_obj_no;
> +     struct c_can_priv *priv = netdev_priv(dev);
> +     struct can_frame *frame = (struct can_frame *)skb->data;
> +
> +     if (can_dropped_invalid_skb(dev, skb))
> +             return NETDEV_TX_OK;
> +
> +     msg_obj_no = get_tx_next_msg_obj(priv);
> +
> +     /* prepare message object for transmission */
> +     val = c_can_write_msg_object(dev, 0, frame, msg_obj_no);
> +
> +     /* enable interrupt for this message object */
> +     priv->write_reg(priv, &priv->regs->intf[0].msg_cntrl,
> +                     IF_MCONT_TXIE | IF_MCONT_TXRQST | IF_MCONT_EOB |
> +                     (val & 0xf));
> +     c_can_object_put(dev, 0, msg_obj_no, IF_COMM_ALL);
> +
> +     can_put_echo_skb(skb, dev, msg_obj_no - C_CAN_MSG_OBJ_TX_FIRST);
> +
> +     priv->tx_next++;
> +     if ((priv->tx_next & C_CAN_NEXT_MSG_OBJ_MASK) == 0)
> +             netif_stop_queue(dev);
> +
> +     return NETDEV_TX_OK;
> +}
> +
> +static int c_can_set_bittiming(struct net_device *dev)
> +{
> +     unsigned int reg_btr, reg_brpe, ctrl_save;
> +     u8 brp, brpe, sjw, tseg1, tseg2;
> +     u32 ten_bit_brp;
> +     struct c_can_priv *priv = netdev_priv(dev);
> +     const struct can_bittiming *bt = &priv->can.bittiming;
> +
> +     /* c_can provides a 6-bit brp and 4-bit brpe fields */
> +     ten_bit_brp = bt->brp - 1;
> +     brp = ten_bit_brp & BTR_BRP_MASK;
> +     brpe = ten_bit_brp >> 6;
> +
> +     sjw = bt->sjw - 1;
> +     tseg1 = bt->prop_seg + bt->phase_seg1 - 1;
> +     tseg2 = bt->phase_seg2 - 1;
> +     reg_btr = brp | (sjw << BTR_SJW_SHIFT) | (tseg1 << BTR_TSEG1_SHIFT) |
> +                     (tseg2 << BTR_TSEG2_SHIFT);
> +     reg_brpe = brpe & BRP_EXT_BRPE_MASK;
> +
> +     dev_info(dev->dev.parent,
> +             "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 | 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);
> +
> +     return 0;
> +}
> +
> +/*
> + * Configure C_CAN message objects for Tx and Rx purposes:
> + * C_CAN provides a total of 32 message objects that can be configured
> + * either for Tx or Rx purposes. Here the first 16 message objects are used 
> as
> + * a reception FIFO. The end of reception FIFO is signified by the EoB bit
> + * being SET. The remaining 16 message objects are kept aside for Tx 
> purposes.
> + * See user guide document for further details on configuring message
> + * objects.
> + */
> +static void c_can_configure_msg_objects(struct net_device *dev)
> +{
> +     int i;
> +
> +     /* first invalidate all message objects */
> +     for (i = 0; i <= C_CAN_NO_OF_OBJECTS; i++)
> +             c_can_inval_msg_object(dev, 0, i);
> +
> +     /* setup receive message objects */
> +     for (i = C_CAN_MSG_OBJ_RX_FIRST + 1 ; i < C_CAN_MSG_OBJ_RX_LAST; i++)
> +             c_can_setup_receive_object(dev, 0, i, 0, 0,
> +                     (IF_MCONT_RXIE | IF_MCONT_UMASK) & ~IF_MCONT_EOB);
> +
> +     c_can_setup_receive_object(dev, 0, C_CAN_MSG_OBJ_RX_LAST, 0, 0,
> +                     IF_MCONT_EOB | IF_MCONT_RXIE | IF_MCONT_UMASK);
> +}
> +
> +/*
> + * Configure C_CAN chip:
> + * - enable/disable auto-retransmission
> + * - set operating mode
> + * - configure message objects
> + */
> +static void c_can_chip_config(struct net_device *dev)
> +{
> +     struct c_can_priv *priv = netdev_priv(dev);
> +
> +     if (priv->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT)
> +             /* disable automatic retransmission */
> +             priv->write_reg(priv, &priv->regs->control,
> +                             CONTROL_DISABLE_AR);
> +     else
> +             /* enable automatic retransmission */
> +             priv->write_reg(priv, &priv->regs->control,
> +                             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 |
> +                             CONTROL_SIE | CONTROL_IE | CONTROL_TEST);
> +             priv->write_reg(priv, &priv->regs->test,
> +                             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 |
> +                             CONTROL_SIE | CONTROL_IE | CONTROL_TEST);
> +             priv->write_reg(priv, &priv->regs->test, TEST_LBACK);
> +     } else if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY) {
> +             /* silent mode : bus-monitoring mode */
> +             priv->write_reg(priv, &priv->regs->control, CONTROL_EIE |
> +                             CONTROL_SIE | CONTROL_IE | CONTROL_TEST);
> +             priv->write_reg(priv, &priv->regs->test, TEST_SILENT);
> +     } else
> +             /* normal mode*/
> +             priv->write_reg(priv, &priv->regs->control,
> +                             CONTROL_EIE | CONTROL_SIE | CONTROL_IE);
> +
> +     /* configure message objects */
> +     c_can_configure_msg_objects(dev);
> +}
> +
> +static void c_can_start(struct net_device *dev)
> +{
> +     struct c_can_priv *priv = netdev_priv(dev);
> +
> +     /* enable status change, error and module interrupts */
> +     c_can_enable_all_interrupts(priv, ENABLE_ALL_INTERRUPTS);
> +
> +     /* basic c_can configuration */
> +     c_can_chip_config(dev);
> +
> +     priv->can.state = CAN_STATE_ERROR_ACTIVE;
> +
> +     /* reset tx helper pointers */
> +     priv->tx_next = priv->tx_echo = 0;
> +}
> +
> +static void c_can_stop(struct net_device *dev)
> +{
> +     struct c_can_priv *priv = netdev_priv(dev);
> +
> +     /* disable all interrupts */
> +     c_can_enable_all_interrupts(priv, DISABLE_ALL_INTERRUPTS);
> +
> +     /* set the state as STOPPED */
> +     priv->can.state = CAN_STATE_STOPPED;
> +}
> +
> +static int c_can_set_mode(struct net_device *dev, enum can_mode mode)
> +{
> +     switch (mode) {
> +     case CAN_MODE_START:
> +             c_can_start(dev);
> +             netif_wake_queue(dev);
> +             break;
> +     default:
> +             return -EOPNOTSUPP;
> +     }
> +
> +     return 0;
> +}
> +
> +static int c_can_get_berr_counter(const struct net_device *dev,
> +                                     struct can_berr_counter *bec)
> +{
> +     unsigned int reg_err_counter;
> +     struct c_can_priv *priv = netdev_priv(dev);
> +
> +     reg_err_counter = priv->read_reg(priv, &priv->regs->err_cnt);
> +     bec->rxerr = (reg_err_counter & ERR_COUNTER_REC_MASK) >>
> +                             ERR_COUNTER_REC_SHIFT;
> +     bec->txerr = reg_err_counter & ERR_COUNTER_TEC_MASK;
> +
> +     return 0;
> +}
> +
> +/*
> + * theory of operation:
> + *
> + * priv->tx_echo holds the number of the oldest can_frame put for
> + * transmission into the hardware, but not yet ACKed by the CAN tx
> + * complete IRQ.
> + *
> + * We iterate from priv->tx_echo to priv->tx_next and check if the
> + * packet has been transmitted, echo it back to the CAN framework.
> + * If we discover a not yet transmitted package, stop looking for more.
> + */
> +static void c_can_do_tx(struct net_device *dev)
> +{
> +     u32 val;
> +     u32 msg_obj_no;
> +     struct c_can_priv *priv = netdev_priv(dev);
> +     struct net_device_stats *stats = &dev->stats;
> +
> +     for (/* nix */; (priv->tx_next - priv->tx_echo) > 0; priv->tx_echo++) {
> +             msg_obj_no = get_tx_echo_msg_obj(priv);
> +             c_can_inval_msg_object(dev, 0, msg_obj_no);
> +             val = c_can_read_reg32(priv, &priv->regs->txrqst1);
> +             if (!(val & (1 << msg_obj_no))) {
> +                     can_get_echo_skb(dev,
> +                                     msg_obj_no - C_CAN_MSG_OBJ_TX_FIRST);
> +                     stats->tx_bytes += priv->read_reg(priv,
> +                                     &priv->regs->intf[0].msg_cntrl)
> +                                     & IF_MCONT_DLC_MASK;
> +                     stats->tx_packets++;
> +             }
> +     }
> +
> +     /* restart queue if wrap-up or if queue stalled on last pkt */
> +     if (((priv->tx_next & C_CAN_NEXT_MSG_OBJ_MASK) != 0) ||
> +                     ((priv->tx_echo & C_CAN_NEXT_MSG_OBJ_MASK) == 0))
> +             netif_wake_queue(dev);
> +}
> +
> +/*
> + * theory of operation:
> + *
> + * c_can core saves a received CAN message into the first free message
> + * object it finds free (starting with the lowest). Bits NEWDAT and
> + * INTPND are set for this message object indicating that a new message
> + * has arrived. To work-around this issue, we keep two groups of message
> + * objects whose partitioning is defined by C_CAN_MSG_OBJ_RX_SPLIT.
> + *
> + * To ensure in-order frame reception we use the following
> + * approach while re-activating a message object to receive further
> + * frames:
> + * - if the current message object number is lower than
> + *   C_CAN_MSG_RX_LOW_LAST, do not clear the NEWDAT bit while clearing
> + *   the INTPND bit.
> + * - if the current message object number is equal to
> + *   C_CAN_MSG_RX_LOW_LAST then clear the NEWDAT bit of all lower
> + *   receive message objects.
> + * - if the current message object number is greater than
> + *   C_CAN_MSG_RX_LOW_LAST then clear the NEWDAT bit of
> + *   only this message object.
> + */
> +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);
> +
> +     for (msg_obj = C_CAN_MSG_OBJ_RX_FIRST;
> +                     msg_obj <= C_CAN_MSG_OBJ_RX_LAST && quota > 0;
> +                     msg_obj++) {
> +             if (val & (1 << msg_obj)) {

what about using find_next_bit here?

> +                     c_can_object_get(dev, 0, msg_obj, IF_COMM_ALL &
> +                                     ~IF_COMM_TXRQST);
> +                     msg_ctrl_save = priv->read_reg(priv,
> +                                     &priv->regs->intf[0].msg_cntrl);
> +
> +                     if (msg_ctrl_save & IF_MCONT_EOB)
> +                             return num_rx_pkts;
> +
> +                     if (msg_ctrl_save & IF_MCONT_MSGLST) {
> +                             c_can_handle_lost_msg_obj(dev, 0, msg_obj);
> +                             num_rx_pkts++;
> +                             quota--;
> +                             continue;
> +                     }
> +
> +                     if (!(msg_ctrl_save & IF_MCONT_NEWDAT))
> +                             continue;
> +
> +                     /* read the data from the message object */
> +                     c_can_read_msg_object(dev, 0, msg_ctrl_save, msg_obj);
> +
> +                     if (msg_obj < C_CAN_MSG_RX_LOW_LAST)
> +                             c_can_mark_rx_msg_obj(dev, 0,
> +                                             msg_ctrl_save, msg_obj);
> +                     else if (msg_obj > C_CAN_MSG_RX_LOW_LAST)
> +                             /* activate this msg obj */
> +                             c_can_activate_rx_msg_obj(dev, 0,
> +                                             msg_ctrl_save, msg_obj);
> +                     else if (msg_obj == C_CAN_MSG_RX_LOW_LAST)
> +                             /* activate all lower message objects */
> +                             c_can_activate_all_lower_rx_msg_obj(dev,
> +                                             0, msg_ctrl_save);
> +
> +                     num_rx_pkts++;
> +                     quota--;
> +             }
> +             val = c_can_read_reg32(priv, &priv->regs->intpnd1);
> +     }
> +
> +     return num_rx_pkts;
> +}
> +
> +static inline int c_can_has_and_handle_berr(struct c_can_priv *priv)
> +{
> +     return (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING) &&
> +             (priv->current_status & STATUS_LEC_MASK);
> +}
> +
> +static int c_can_err(struct net_device *dev,
> +                             enum c_can_bus_error_types error_type,
> +                             enum c_can_lec_type lec_type)
> +{
> +     unsigned int reg_err_counter;
> +     unsigned int rx_err_passive;
> +     struct c_can_priv *priv = netdev_priv(dev);
> +     struct net_device_stats *stats = &dev->stats;
> +     struct can_frame *cf;
> +     struct sk_buff *skb;
> +     struct can_berr_counter bec;
> +
> +     /* propogate the error condition to the CAN stack */
> +     skb = alloc_can_err_skb(dev, &cf);
> +     if (unlikely(!skb))
> +             return 0;
> +
> +     c_can_get_berr_counter(dev, &bec);
> +     reg_err_counter = priv->read_reg(priv, &priv->regs->err_cnt);
> +     rx_err_passive = (reg_err_counter & ERR_COUNTER_RP_MASK) >>
> +                             ERR_COUNTER_RP_SHIFT;
> +
> +     if (error_type & C_CAN_ERROR_WARNING) {
> +             /* error warning state */
> +             priv->can.can_stats.error_warning++;
> +             priv->can.state = CAN_STATE_ERROR_WARNING;
> +             cf->can_id |= CAN_ERR_CRTL;
> +             if (bec.rxerr > 96)
> +                     cf->data[1] |= CAN_ERR_CRTL_RX_WARNING;
> +             if (bec.txerr > 96)
> +                     cf->data[1] |= CAN_ERR_CRTL_TX_WARNING;
> +     }
> +     if (error_type & C_CAN_ERROR_PASSIVE) {
> +             /* error passive state */
> +             priv->can.can_stats.error_passive++;
> +             priv->can.state = CAN_STATE_ERROR_PASSIVE;
> +             cf->can_id |= CAN_ERR_CRTL;
> +             if (rx_err_passive)
> +                     cf->data[1] |= CAN_ERR_CRTL_RX_PASSIVE;
> +             if (bec.txerr > 127)
> +                     cf->data[1] |= CAN_ERR_CRTL_TX_PASSIVE;
> +     }
> +     if (error_type & C_CAN_BUS_OFF) {
> +             /* bus-off state */
> +             priv->can.state = CAN_STATE_BUS_OFF;
> +             cf->can_id |= CAN_ERR_BUSOFF;
> +             /*
> +              * disable all interrupts in bus-off mode to ensure that
> +              * the CPU is not hogged down
> +              */
> +             c_can_enable_all_interrupts(priv, DISABLE_ALL_INTERRUPTS);
> +             can_bus_off(dev);
> +     }
> +
> +     /*
> +      * check for 'last error code' which tells us the
> +      * type of the last error to occur on the CAN bus
> +      */
> +
> +     /* common for all type of bus errors */
> +     priv->can.can_stats.bus_error++;
> +     stats->rx_errors++;
> +     cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
> +     cf->data[2] |= CAN_ERR_PROT_UNSPEC;
> +
> +     switch (lec_type) {
> +     case LEC_STUFF_ERROR:
> +             dev_dbg(dev->dev.parent, "stuff error\n");
> +             cf->data[2] |= CAN_ERR_PROT_STUFF;
> +             break;
> +
> +     case LEC_FORM_ERROR:
> +             dev_dbg(dev->dev.parent, "form error\n");
> +             cf->data[2] |= CAN_ERR_PROT_FORM;
> +             break;
> +
> +     case LEC_ACK_ERROR:
> +             dev_dbg(dev->dev.parent, "ack error\n");
> +             cf->data[2] |= (CAN_ERR_PROT_LOC_ACK |
> +                             CAN_ERR_PROT_LOC_ACK_DEL);
> +             break;
> +
> +     case LEC_BIT1_ERROR:
> +             dev_dbg(dev->dev.parent, "bit1 error\n");
> +             cf->data[2] |= CAN_ERR_PROT_BIT1;
> +             break;
> +
> +     case LEC_BIT0_ERROR:
> +             dev_dbg(dev->dev.parent, "bit0 error\n");
> +             cf->data[2] |= CAN_ERR_PROT_BIT0;
> +             break;
> +
> +     case LEC_CRC_ERROR:
> +             dev_dbg(dev->dev.parent, "CRC error\n");
> +             cf->data[2] |= (CAN_ERR_PROT_LOC_CRC_SEQ |
> +                             CAN_ERR_PROT_LOC_CRC_DEL);
> +             break;
> +     }
> +
> +     netif_receive_skb(skb);
> +     stats->rx_packets++;
> +     stats->rx_bytes += cf->can_dlc;
> +
> +     return 1;
> +}
> +
> +static int c_can_poll(struct napi_struct *napi, int quota)
> +{
> +     u16 irqstatus;
> +     int lec_type = 0;
> +     int work_done = 0;
> +     struct net_device *dev = napi->dev;
> +     struct c_can_priv *priv = netdev_priv(dev);
> +     enum c_can_bus_error_types error_type = C_CAN_NO_ERROR;
> +
> +     irqstatus = priv->read_reg(priv, &priv->regs->interrupt);
> +
> +     /* status events have the highest priority */
> +     if (irqstatus == STATUS_INTERRUPT) {
> +             priv->current_status = priv->read_reg(priv,
> +                                     &priv->regs->status);
> +
> +             /* handle Tx/Rx events */
> +             if (priv->current_status & STATUS_TXOK)
> +                     priv->write_reg(priv, &priv->regs->status,
> +                                     priv->current_status & ~STATUS_TXOK);
> +
> +             if (priv->current_status & STATUS_RXOK)
> +                     priv->write_reg(priv, &priv->regs->status,
> +                                     priv->current_status & ~STATUS_RXOK);
> +
> +             /* handle bus error events */
> +             if (priv->current_status & STATUS_EWARN) {
> +                     dev_dbg(dev->dev.parent,
> +                                     "entered error warning state\n");
> +                     error_type = C_CAN_ERROR_WARNING;
> +             }
> +             if ((priv->current_status & STATUS_EPASS) &&
> +                             (!(priv->last_status & STATUS_EPASS))) {
> +                     dev_dbg(dev->dev.parent,
> +                                     "entered error passive state\n");
> +                     error_type = C_CAN_ERROR_PASSIVE;
> +             }
> +             if ((priv->current_status & STATUS_BOFF) &&
> +                             (!(priv->last_status & STATUS_BOFF))) {
> +                     dev_dbg(dev->dev.parent,
> +                                     "entered bus off state\n");
> +                     error_type = C_CAN_BUS_OFF;
> +             }
> +
> +             /* handle bus recovery events */
> +             if ((!(priv->current_status & STATUS_EPASS)) &&
> +                             (priv->last_status & STATUS_EPASS)) {
> +                     dev_dbg(dev->dev.parent,
> +                                     "left error passive state\n");
> +                     priv->can.state = CAN_STATE_ERROR_ACTIVE;
> +             }
> +             if ((!(priv->current_status & STATUS_BOFF)) &&
> +                             (priv->last_status & STATUS_BOFF)) {
> +                     dev_dbg(dev->dev.parent,
> +                                     "left bus off state\n");
> +                     priv->can.state = CAN_STATE_ERROR_ACTIVE;
> +             }
> +
> +             priv->last_status = priv->current_status;
> +
> +             /* handle error on the bus */
> +             lec_type = c_can_has_and_handle_berr(priv);
> +             if (lec_type && (error_type != C_CAN_NO_ERROR))
> +                     work_done += c_can_err(dev, error_type, lec_type);
> +     } else if ((irqstatus > C_CAN_MSG_OBJ_RX_FIRST) &&
> +                     (irqstatus <= C_CAN_MSG_OBJ_RX_LAST)) {
> +             /* handle events corresponding to receive message objects */
> +             work_done += c_can_do_rx_poll(dev, (quota - work_done));
> +     } else if ((irqstatus > C_CAN_MSG_OBJ_TX_FIRST) &&
> +                     (irqstatus <= C_CAN_MSG_OBJ_TX_LAST)) {
> +             /* handle events corresponding to transmit message objects */
> +             c_can_do_tx(dev);
> +     }
> +
> +     if (work_done < quota) {
> +             napi_complete(napi);
> +             /* enable all IRQs */
> +             c_can_enable_all_interrupts(priv, ENABLE_ALL_INTERRUPTS);
> +     }
> +
> +     return work_done;
> +}
> +
> +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);
> +
> +     /* disable all interrupts and schedule the NAPI */
> +     c_can_enable_all_interrupts(priv, DISABLE_ALL_INTERRUPTS);
> +     napi_schedule(&priv->napi);
> +
> +     return IRQ_HANDLED;
> +}

Have a look at the pch_can interrupt handler, it supports shared irqs.
> +
> +static int c_can_open(struct net_device *dev)
> +{
> +     int err;
> +     struct c_can_priv *priv = netdev_priv(dev);
> +
> +     /* open the can device */
> +     err = open_candev(dev);
> +     if (err) {
> +             dev_err(dev->dev.parent, "failed to open can device\n");
> +             return err;
> +     }
> +
> +     /* register interrupt handler */
> +     err = request_irq(dev->irq, &c_can_isr, priv->irq_flags, dev->name,
> +                             dev);
> +     if (err < 0) {
> +             dev_err(dev->dev.parent, "failed to request interrupt\n");
> +             goto exit_irq_fail;
> +     }
> +
> +     /* start the c_can controller */
> +     c_can_start(dev);
> +
> +     napi_enable(&priv->napi);
> +     netif_start_queue(dev);
> +
> +     return 0;
> +
> +exit_irq_fail:
> +     close_candev(dev);
> +     return err;
> +}
> +
> +static int c_can_close(struct net_device *dev)
> +{
> +     struct c_can_priv *priv = netdev_priv(dev);
> +
> +     netif_stop_queue(dev);
> +     napi_disable(&priv->napi);
> +     c_can_stop(dev);
> +     free_irq(dev->irq, dev);
> +     close_candev(dev);
> +
> +     return 0;
> +}
> +
> +struct net_device *alloc_c_can_dev(void)

Please model after alloc_sja1000_dev:

struct net_device *alloc_sja1000dev(int sizeof_priv)

The private for the _user_ of alloc_c_can_dev is behind the sja1000
private, so you can get rid of the void *priv member in the struct
c_can_priv. (see below)

> +{
> +     struct net_device *dev;
> +     struct c_can_priv *priv;
> +
> +     dev = alloc_candev(sizeof(struct c_can_priv), C_CAN_MSG_OBJ_TX_NUM);
> +     if (!dev)
> +             return NULL;
> +
> +     priv = netdev_priv(dev);
> +     netif_napi_add(dev, &priv->napi, c_can_poll, C_CAN_NAPI_WEIGHT);
> +
> +     priv->dev = dev;
> +     priv->can.bittiming_const = &c_can_bittiming_const;
> +     priv->can.do_set_bittiming = c_can_set_bittiming;
> +     priv->can.do_set_mode = c_can_set_mode;
> +     priv->can.do_get_berr_counter = c_can_get_berr_counter;
> +     priv->can.ctrlmode_supported = CAN_CTRLMODE_ONE_SHOT |
> +                                     CAN_CTRLMODE_LOOPBACK |
> +                                     CAN_CTRLMODE_LISTENONLY |
> +                                     CAN_CTRLMODE_BERR_REPORTING;
> +
> +     return dev;
> +}
> +EXPORT_SYMBOL_GPL(alloc_c_can_dev);
> +
> +void free_c_can_dev(struct net_device *dev)
> +{
> +     free_candev(dev);
> +}
> +EXPORT_SYMBOL_GPL(free_c_can_dev);
> +
> +static const struct net_device_ops c_can_netdev_ops = {
> +     .ndo_open = c_can_open,
> +     .ndo_stop = c_can_close,
> +     .ndo_start_xmit = c_can_start_xmit,
> +};
> +
> +int register_c_can_dev(struct net_device *dev)
> +{
> +     dev->flags |= IFF_ECHO; /* we support local echo */
> +     dev->netdev_ops = &c_can_netdev_ops;
> +
> +     return register_candev(dev);
> +}
> +EXPORT_SYMBOL_GPL(register_c_can_dev);
> +
> +void unregister_c_can_dev(struct net_device *dev)
> +{
> +     struct c_can_priv *priv = netdev_priv(dev);
> +
> +     /* disable all interrupts */
> +     c_can_enable_all_interrupts(priv, DISABLE_ALL_INTERRUPTS);
> +
> +     unregister_candev(dev);
> +}
> +EXPORT_SYMBOL_GPL(unregister_c_can_dev);
> +
> +MODULE_AUTHOR("Bhupesh Sharma <[email protected]>");
> +MODULE_LICENSE("GPL v2");
> +MODULE_DESCRIPTION("CAN bus driver for Bosch C_CAN controller");
> diff --git a/drivers/net/can/c_can/c_can.h b/drivers/net/can/c_can/c_can.h
> new file mode 100644
> index 0000000..6d24432
> --- /dev/null
> +++ b/drivers/net/can/c_can/c_can.h
> @@ -0,0 +1,235 @@
> +/*
> + * CAN bus driver for Bosch C_CAN controller
> + *
> + * Copyright (C) 2010 ST Microelectronics
> + * Bhupesh Sharma <[email protected]>
> + *
> + * Borrowed heavily from the C_CAN driver originally written by:
> + * Copyright (C) 2007
> + * - Sascha Hauer, Marc Kleine-Budde, Pengutronix <[email protected]>
> + * - Simon Kallweit, intefo AG <[email protected]>
> + *
> + * TX and RX NAPI implementation has been borrowed from at91 CAN driver
> + * written by:
> + * Copyright
> + * (C) 2007 by Hans J. Koch <[email protected]>
> + * (C) 2008, 2009 by Marc Kleine-Budde <[email protected]>

IMHO you can drop the at91 copyright reference here.

> + *
> + * Bosch C_CAN controller is compliant to CAN protocol version 2.0 part A 
> and B.
> + * Bosch C_CAN user manual can be obtained from:
> + * http://www.semiconductors.bosch.de/media/en/pdf/ipmodules_1/c_can/
> + * users_manual_c_can.pdf
> + *
> + * This file is licensed under the terms of the GNU General Public
> + * License version 2. This program is licensed "as is" without any
> + * warranty of any kind, whether express or implied.
> + */
> +
> +#ifndef C_CAN_H
> +#define C_CAN_H
> +
> +/* control register */
> +#define CONTROL_TEST         BIT(7)
> +#define CONTROL_CCE          BIT(6)
> +#define CONTROL_DISABLE_AR   BIT(5)
> +#define CONTROL_ENABLE_AR    (0 << 5)
> +#define CONTROL_EIE          BIT(3)
> +#define CONTROL_SIE          BIT(2)
> +#define CONTROL_IE           BIT(1)
> +#define CONTROL_INIT         BIT(0)
> +
> +/* test register */
> +#define TEST_RX                      BIT(7)
> +#define TEST_TX1             BIT(6)
> +#define TEST_TX2             BIT(5)
> +#define TEST_LBACK           BIT(4)
> +#define TEST_SILENT          BIT(3)
> +#define TEST_BASIC           BIT(2)
> +
> +/* status register */
> +#define STATUS_BOFF          BIT(7)
> +#define STATUS_EWARN         BIT(6)
> +#define STATUS_EPASS         BIT(5)
> +#define STATUS_RXOK          BIT(4)
> +#define STATUS_TXOK          BIT(3)
> +#define STATUS_LEC_MASK              0x07
> +
> +/* error counter register */
> +#define ERR_COUNTER_TEC_MASK 0xff
> +#define ERR_COUNTER_TEC_SHIFT        0
> +#define ERR_COUNTER_REC_SHIFT        8
> +#define ERR_COUNTER_REC_MASK (0x7f << ERR_COUNTER_REC_SHIFT)
> +#define ERR_COUNTER_RP_SHIFT 15
> +#define ERR_COUNTER_RP_MASK  (0x1 << ERR_COUNTER_RP_SHIFT)
> +
> +/* bit-timing register */
> +#define BTR_BRP_MASK         0x3f
> +#define BTR_BRP_SHIFT                0
> +#define BTR_SJW_SHIFT                6
> +#define BTR_SJW_MASK         (0x3 << BTR_SJW_SHIFT)
> +#define BTR_TSEG1_SHIFT              8
> +#define BTR_TSEG1_MASK               (0xf << BTR_TSEG1_SHIFT)
> +#define BTR_TSEG2_SHIFT              12
> +#define BTR_TSEG2_MASK               (0x7 << BTR_TSEG2_SHIFT)
> +
> +/* brp extension register */
> +#define BRP_EXT_BRPE_MASK    0x0f
> +#define BRP_EXT_BRPE_SHIFT   0
> +
> +/* IFx command request */
> +#define IF_COMR_BUSY         BIT(15)
> +
> +/* IFx command mask */
> +#define IF_COMM_WR           BIT(7)
> +#define IF_COMM_MASK         BIT(6)
> +#define IF_COMM_ARB          BIT(5)
> +#define IF_COMM_CONTROL              BIT(4)
> +#define IF_COMM_CLR_INT_PND  BIT(3)
> +#define IF_COMM_TXRQST               BIT(2)
> +#define IF_COMM_DATAA                BIT(1)
> +#define IF_COMM_DATAB                BIT(0)
> +#define IF_COMM_ALL          (IF_COMM_MASK | IF_COMM_ARB | \
> +                             IF_COMM_CONTROL | IF_COMM_TXRQST | \
> +                             IF_COMM_DATAA | IF_COMM_DATAB)
> +
> +/* IFx arbitration */
> +#define IF_ARB_MSGVAL                BIT(15)
> +#define IF_ARB_MSGXTD                BIT(14)
> +#define IF_ARB_TRANSMIT              BIT(13)
> +
> +/* IFx message control */
> +#define IF_MCONT_NEWDAT              BIT(15)
> +#define IF_MCONT_MSGLST              BIT(14)
> +#define IF_MCONT_CLR_MSGLST  (0 << 14)
> +#define IF_MCONT_INTPND              BIT(13)
> +#define IF_MCONT_UMASK               BIT(12)
> +#define IF_MCONT_TXIE                BIT(11)
> +#define IF_MCONT_RXIE                BIT(10)
> +#define IF_MCONT_RMTEN               BIT(9)
> +#define IF_MCONT_TXRQST              BIT(8)
> +#define IF_MCONT_EOB         BIT(7)
> +#define IF_MCONT_DLC_MASK    0xf
> +
> +/*
> + * IFx register masks:
> + * allow easy operation on 16-bit registers when the
> + * argument is 32-bit instead
> + */
> +#define IFX_WRITE_LOW_16BIT(x)       ((x) & 0xFFFF)
> +#define IFX_WRITE_HIGH_16BIT(x)      (((x) & 0xFFFF0000) >> 16)
> +
> +/* message object split */
> +#define C_CAN_NO_OF_OBJECTS  31
> +#define C_CAN_MSG_OBJ_RX_NUM 16
> +#define C_CAN_MSG_OBJ_TX_NUM 16
> +
> +#define C_CAN_MSG_OBJ_RX_FIRST       0
> +#define C_CAN_MSG_OBJ_RX_LAST        (C_CAN_MSG_OBJ_RX_FIRST + \
> +                             C_CAN_MSG_OBJ_RX_NUM - 1)
> +
> +#define C_CAN_MSG_OBJ_TX_FIRST       (C_CAN_MSG_OBJ_RX_LAST + 1)
> +#define C_CAN_MSG_OBJ_TX_LAST        (C_CAN_MSG_OBJ_TX_FIRST + \
> +                             C_CAN_MSG_OBJ_TX_NUM - 1)
> +
> +#define C_CAN_MSG_OBJ_RX_SPLIT       8
> +#define C_CAN_MSG_RX_LOW_LAST        (C_CAN_MSG_OBJ_RX_SPLIT - 1)
> +
> +#define C_CAN_NEXT_MSG_OBJ_MASK      (C_CAN_MSG_OBJ_TX_NUM - 1)
> +#define RECEIVE_OBJECT_BITS  0x0000ffff
> +
> +/* status interrupt */
> +#define STATUS_INTERRUPT     0x8000
> +
> +/* global interrupt masks */
> +#define ENABLE_ALL_INTERRUPTS        1
> +#define DISABLE_ALL_INTERRUPTS       0
> +
> +/* minimum timeout for checking BUSY status */
> +#define MIN_TIMEOUT_VALUE    6
> +
> +/* napi related */
> +#define C_CAN_NAPI_WEIGHT    C_CAN_MSG_OBJ_RX_NUM
> +
> +/* c_can IF registers */
> +struct c_can_if_regs {
> +     u16 com_reg;
> +     u16 com_mask;
> +     u16 mask1;
> +     u16 mask2;
> +     u16 arb1;
> +     u16 arb2;
> +     u16 msg_cntrl;
> +     u16 data[4];
> +     u16 _reserved[13];
> +};
> +
> +/* 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 intf[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];
> +};
> +
> +/* c_can lec values */
> +enum c_can_lec_type {
> +     LEC_STUFF_ERROR = 1,
> +     LEC_FORM_ERROR,
> +     LEC_ACK_ERROR,
> +     LEC_BIT1_ERROR,
> +     LEC_BIT0_ERROR,
> +     LEC_CRC_ERROR,
> +};
> +
> +/*
> + * c_can error types:
> + * Bus errors (BUS_OFF, ERROR_WARNING, ERROR_PASSIVE) are supported
> + */
> +enum c_can_bus_error_types {
> +     C_CAN_NO_ERROR = 0,
> +     C_CAN_BUS_OFF,
> +     C_CAN_ERROR_WARNING,
> +     C_CAN_ERROR_PASSIVE,
> +};
> +
> +/* c_can private data structure */
> +struct c_can_priv {
> +     struct can_priv can;    /* must be the first member */
> +     struct napi_struct napi;
> +     struct net_device *dev;
> +     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;
> +     unsigned long irq_flags; /* for request_irq() */
> +     unsigned int tx_next;
> +     unsigned int tx_echo;
> +     void *priv;             /* for board-specific data */
        ^^^^^^^^^^

here

> +};
> +
> +struct net_device *alloc_c_can_dev(void);
> +void free_c_can_dev(struct net_device *dev);
> +int register_c_can_dev(struct net_device *dev);
> +void unregister_c_can_dev(struct net_device *dev);
> +
> +#endif /* C_CAN_H */
> diff --git a/drivers/net/can/c_can/c_can_platform.c 
> b/drivers/net/can/c_can/c_can_platform.c
> new file mode 100644
> index 0000000..6ec0471
> --- /dev/null
> +++ b/drivers/net/can/c_can/c_can_platform.c
> @@ -0,0 +1,208 @@
> +/*
> + * Platform CAN bus driver for Bosch C_CAN controller
> + *
> + * Copyright (C) 2010 ST Microelectronics
> + * Bhupesh Sharma <[email protected]>
> + *
> + * Borrowed heavily from the C_CAN driver originally written by:
> + * Copyright (C) 2007
> + * - Sascha Hauer, Marc Kleine-Budde, Pengutronix <[email protected]>
> + * - Simon Kallweit, intefo AG <[email protected]>
> + *
> + * Bosch C_CAN controller is compliant to CAN protocol version 2.0 part A 
> and B.
> + * Bosch C_CAN user manual can be obtained from:
> + * http://www.semiconductors.bosch.de/media/en/pdf/ipmodules_1/c_can/
> + * users_manual_c_can.pdf
> + *
> + * This file is licensed under the terms of the GNU General Public
> + * License version 2. This program is licensed "as is" without any
> + * warranty of any kind, whether express or implied.
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/version.h>
> +#include <linux/module.h>
> +#include <linux/interrupt.h>
> +#include <linux/delay.h>
> +#include <linux/netdevice.h>
> +#include <linux/if_arp.h>
> +#include <linux/if_ether.h>
> +#include <linux/list.h>
> +#include <linux/delay.h>
> +#include <linux/io.h>
> +#include <linux/platform_device.h>
> +#include <linux/clk.h>
> +
> +#include <linux/can/dev.h>
> +
> +#include "c_can.h"
> +
> +/*
> + * 16-bit c_can registers can be arranged differently in the memory
> + * architecture of different implementations. For example: 16-bit
> + * registers can be aligned to a 16-bit boundary or 32-bit boundary etc.
> + * 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)
> +{
> +     return readw(reg);
> +}
> +
> +static void c_can_plat_write_reg_aligned_to_16bit(struct c_can_priv *priv,
> +                                             void *reg, u16 val)
> +{
> +     writew(val, reg);
> +}
> +
> +static u16 c_can_plat_read_reg_aligned_to_32bit(struct c_can_priv *priv,
> +                                             void *reg)
> +{
> +     return readw(reg + (long)reg - (long)priv->regs);
> +}
> +
> +static void c_can_plat_write_reg_aligned_to_32bit(struct c_can_priv *priv,
> +                                             void *reg, u16 val)
> +{
> +     writew(val, reg + (long)reg - (long)priv->regs);
> +}
> +
> +static int __devinit c_can_plat_probe(struct platform_device *pdev)
> +{
> +     int ret;
> +     void __iomem *addr;
> +     struct net_device *dev;
> +     struct c_can_priv *priv;
> +     struct resource *mem, *irq;
> +     struct clk *clk;
> +
> +     /* get the appropriate clk */
> +     clk = clk_get(&pdev->dev, NULL);
> +     if (IS_ERR(clk)) {
> +             dev_err(&pdev->dev, "no clock defined\n");
> +             ret = -ENODEV;
> +             goto exit;
> +     }
> +
> +     /* get the platform data */
> +     mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +     irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
> +     if (!mem || (irq <= 0)) {
> +             ret = -ENODEV;
> +             goto exit_free_clk;
> +     }
> +
> +     if (!request_mem_region(mem->start, resource_size(mem),
> +                             KBUILD_MODNAME)) {
> +             dev_err(&pdev->dev, "resource unavailable\n");
> +             ret = -ENODEV;
> +             goto exit_free_clk;
> +     }
> +
> +     addr = ioremap(mem->start, resource_size(mem));
> +     if (!addr) {
> +             dev_err(&pdev->dev, "failed to map can port\n");
> +             ret = -ENOMEM;
> +             goto exit_release_mem;
> +     }
> +
> +     /* allocate the c_can device */
> +     dev = alloc_c_can_dev();
> +     if (!dev) {
> +             ret = -ENOMEM;
> +             goto exit_iounmap;
> +     }
> +
> +     priv = netdev_priv(dev);
> +
> +     dev->irq = irq->start;
> +     priv->irq_flags = irq->flags;
> +     priv->regs = addr;
> +     priv->can.clock.freq = clk_get_rate(clk);
> +     priv->priv = clk;
> +
> +     switch (mem->flags & IORESOURCE_MEM_TYPE_MASK) {
> +     case IORESOURCE_MEM_32BIT:
> +             priv->read_reg = c_can_plat_read_reg_aligned_to_32bit;
> +             priv->write_reg = c_can_plat_write_reg_aligned_to_32bit;
> +             break;
> +     case IORESOURCE_MEM_16BIT:
> +     default:
> +             priv->read_reg = c_can_plat_read_reg_aligned_to_16bit;
> +             priv->write_reg = c_can_plat_write_reg_aligned_to_16bit;
> +             break;
> +     }
> +
> +     platform_set_drvdata(pdev, dev);
> +     SET_NETDEV_DEV(dev, &pdev->dev);
> +
> +     ret = register_c_can_dev(dev);
> +     if (ret) {
> +             dev_err(&pdev->dev, "registering %s failed (err=%d)\n",
> +                     KBUILD_MODNAME, ret);
> +             goto exit_free_device;
> +     }
> +
> +     dev_info(&pdev->dev, "%s device registered (regs=%p, irq=%d)\n",
> +              KBUILD_MODNAME, priv->regs, dev->irq);
> +     return 0;
> +
> +exit_free_device:
> +     platform_set_drvdata(pdev, NULL);
> +     free_c_can_dev(dev);
> +exit_iounmap:
> +     iounmap(addr);
> +exit_release_mem:
> +     release_mem_region(mem->start, resource_size(mem));
> +exit_free_clk:
> +     clk_put(clk);
> +exit:
> +     dev_err(&pdev->dev, "probe failed\n");
> +
> +     return ret;
> +}
> +
> +static int __devexit c_can_plat_remove(struct platform_device *pdev)
> +{
> +     struct net_device *dev = platform_get_drvdata(pdev);
> +     struct c_can_priv *priv = netdev_priv(dev);
> +     struct resource *mem;
> +
> +     unregister_c_can_dev(dev);
> +     platform_set_drvdata(pdev, NULL);
> +
> +     free_c_can_dev(dev);
> +     iounmap(priv->regs);
> +
> +     mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +     release_mem_region(mem->start, resource_size(mem));
> +
> +     clk_put(priv->priv);
> +
> +     return 0;
> +}
> +
> +static struct platform_driver c_can_plat_driver = {
> +     .driver = {
> +             .name = KBUILD_MODNAME,
> +             .owner = THIS_MODULE,
> +     },
> +     .probe = c_can_plat_probe,
> +     .remove = __devexit_p(c_can_plat_remove),
> +};
> +
> +static int __init c_can_plat_init(void)
> +{
> +     return platform_driver_register(&c_can_plat_driver);
> +}
> +module_init(c_can_plat_init);
> +
> +static void __exit c_can_plat_exit(void)
> +{
> +     platform_driver_unregister(&c_can_plat_driver);
> +}
> +module_exit(c_can_plat_exit);
> +
> +MODULE_AUTHOR("Bhupesh Sharma <[email protected]>");
> +MODULE_LICENSE("GPL v2");
> +MODULE_DESCRIPTION("Platform CAN bus driver for Bosch C_CAN controller");

[1]
https://lists.berlios.de/pipermail/socketcan-core/2011-January/005331.html

[2]
http://git.pengutronix.de/?p=mkl/linux-2.6.git;a=commit;h=3df3682c0e2c192714885f67fff89d1d3849d533

regards, 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   |

Attachment: signature.asc
Description: OpenPGP digital signature

_______________________________________________
Socketcan-core mailing list
[email protected]
https://lists.berlios.de/mailman/listinfo/socketcan-core

Reply via email to