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Message-ID: <D5ECB3C7A6F99444980976A8C6D896384DEAE47E2E@EAPEX1MAIL1.st.com>
Date:	Mon, 20 Dec 2010 12:37:03 +0800
From:	Bhupesh SHARMA <bhupesh.sharma@...com>
To:	Marc Kleine-Budde <mkl@...gutronix.de>
Cc:	"netdev@...r.kernel.org" <netdev@...r.kernel.org>,
	"Socketcan-core@...ts.berlios.de" <Socketcan-core@...ts.berlios.de>,
	Wolfgang Grandegger <wg@...ndegger.com>
Subject: RE: [PATCH net-next-2.6 v2 1/1] can: c_can: Added support for Bosch
 C_CAN controller

Hi Marc,

Thanks for the review.
Please see my comments in-line:

> No time to do a real review, some comments and lots of nitpicking
> inline....
>
> regards, Marc
>
> >
> > 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.
> >
> > Changes since V1:
> > 1. Implemented C_CAN as a platform driver with means of providing the
> >    platform details and register offsets which may vary for different
> SoCs
> >    through platform data struct.
> > 2. Implemented NAPI.
> > 3. Removed memcpy calls globally.
> > 4. Implemented CAN_CTRLMODE_*
> > 5. Implemented and used priv->can.do_get_berr_counter.
> > 6. Implemented c_can registers as a struct instead of enum.
> > 7. Improved the TX path by implementing routines to get next Tx and
> echo msg
> >    objects.
> >
> > Signed-off-by: Bhupesh Sharma <bhupesh.sharma@...com>
> > ---
> >  drivers/net/can/Kconfig  |    7 +
> >  drivers/net/can/Makefile |    1 +
> >  drivers/net/can/c_can.c  | 1217
> > ++++++++++++++++++++++++++++++++++++++++++++++
> >  3 files changed, 1225 insertions(+), 0 deletions(-)  create mode
> > 100644 drivers/net/can/c_can.c
> >
> > diff --git a/drivers/net/can/Kconfig b/drivers/net/can/Kconfig index
> > 9d9e453..25d9d2e 100644
> > --- a/drivers/net/can/Kconfig
> > +++ b/drivers/net/can/Kconfig
> > @@ -41,6 +41,13 @@ config CAN_AT91
> >     ---help---
> >       This is a driver for the SoC CAN controller in Atmel's
> AT91SAM9263.
> >
> > +config CAN_C_CAN
> > +   tristate "Bosch C_CAN controller"
> > +   depends on CAN_DEV
> > +   ---help---
> > +     If you say yes to this option, support will be included for the
> > +     Bosch C_CAN controller.
> > +
> >  config CAN_TI_HECC
> >     depends on CAN_DEV && ARCH_OMAP3
> >     tristate "TI High End CAN Controller"
> > diff --git a/drivers/net/can/Makefile b/drivers/net/can/Makefile
> index
> > 0057537..b6cbe74 100644
> > --- a/drivers/net/can/Makefile
> > +++ b/drivers/net/can/Makefile
> > @@ -12,6 +12,7 @@ obj-y                             += usb/
> >  obj-$(CONFIG_CAN_SJA1000)  += sja1000/
> >  obj-$(CONFIG_CAN_MSCAN)            += mscan/
> >  obj-$(CONFIG_CAN_AT91)             += at91_can.o
> > +obj-$(CONFIG_CAN_C_CAN)            += c_can.o
> >  obj-$(CONFIG_CAN_TI_HECC)  += ti_hecc.o
> >  obj-$(CONFIG_CAN_MCP251X)  += mcp251x.o
> >  obj-$(CONFIG_CAN_BFIN)             += bfin_can.o
> > diff --git a/drivers/net/can/c_can.c b/drivers/net/can/c_can.c new
> > file mode 100644 index 0000000..c281c17
> > --- /dev/null
> > +++ b/drivers/net/can/c_can.c
> > @@ -0,0 +1,1217 @@
> > +/*
> > + * CAN bus driver for Bosch C_CAN controller
> > + *
> > + * Copyright (C) 2010 ST Microelectronics
> > + * Bhupesh Sharma <bhupesh.sharma@...com>
> > + *
> > + * Borrowed heavily from the C_CAN driver originally written by:
> > + * Copyright (C) 2007
> > + * - Sascha Hauer, Marc Kleine-Budde, Pengutronix
> > +<s.hauer@...gutronix.de>
> > + * - Simon Kallweit, intefo AG <simon.kallweit@...efo.ch>
> > + *
>
> I recognize some stuff from the at91_can driver, too :)

Yes. And if you and Wolfgang agree to using the at91 approach
for in-order rx object reception here, I will be compelled to
add credits 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/pdf/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/workqueue.h>
> > +#include <linux/io.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/clk.h>
> > +
> > +#include <linux/can.h>
> > +#include <linux/can/dev.h>
> > +#include <linux/can/error.h>
> > +
> > +#define DRV_NAME "c_can"
>
> You can use KBUILD_MODNAME, no need to define DRV_NAME.

Ok.

> > +
> > +/* control register */
> > +#define CONTROL_TEST               (1 << 7)
> > +#define CONTROL_CCE                (1 << 6)
> > +#define CONTROL_DISABLE_AR (1 << 5)
> > +#define CONTROL_ENABLE_AR  (0 << 5)
> > +#define CONTROL_EIE                (1 << 3)
> > +#define CONTROL_SIE                (1 << 2)
> > +#define CONTROL_IE         (1 << 1)
> > +#define CONTROL_INIT               (1 << 0)
> > +
> > +/* test register */
> > +#define TEST_RX                    (1 << 7)
> > +#define TEST_TX1           (1 << 6)
> > +#define TEST_TX2           (1 << 5)
> > +#define TEST_LBACK         (1 << 4)
> > +#define TEST_SILENT                (1 << 3)
> > +#define TEST_BASIC         (1 << 2)
>
> You can use BIT(n) instead of (1 << n).

Ok.

> > +
> > +/* status register */
> > +#define STATUS_BOFF                (1 << 7)
> > +#define STATUS_EWARN               (1 << 6)
> > +#define STATUS_EPASS               (1 << 5)
> > +#define STATUS_RXOK                (1 << 4)
> > +#define STATUS_TXOK                (1 << 3)
> > +#define STATUS_LEC_MASK            0x07
> > +#define LEC_STUFF_ERROR            1
> > +#define LEC_FORM_ERROR             2
> > +#define LEC_ACK_ERROR              3
> > +#define LEC_BIT1_ERROR             4
> > +#define LEC_BIT0_ERROR             5
> > +#define LEC_CRC_ERROR              6
> > +
> > +/* error counter register */
> > +#define ERR_COUNTER_TEC_MASK       0xff
> > +#define ERR_COUNTER_TEC_SHIFT      0x0
>
> nitpick, I'd just use a pure decimal 0 :)

Hmm. Ok :)

> > +#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               (1 << 15)
> > +
> > +/* IFx command mask */
> > +#define IF_COMM_WR         (1 << 7)
> > +#define IF_COMM_MASK               (1 << 6)
> > +#define IF_COMM_ARB                (1 << 5)
> > +#define IF_COMM_CONTROL            (1 << 4)
> > +#define IF_COMM_CLR_INT_PND        (1 << 3)
> > +#define IF_COMM_TXRQST             (1 << 2)
> > +#define IF_COMM_DATAA              (1 << 1)
> > +#define IF_COMM_DATAB              (1 << 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              (1 << 15)
> > +#define IF_ARB_MSGXTD              (1 << 14)
> > +#define IF_ARB_TRANSMIT            (1 << 13)
> > +
> > +/* IFx message control */
> > +#define IF_MCONT_NEWDAT            (1 << 15)
> > +#define IF_MCONT_MSGLST            (1 << 14)
> > +#define IF_MCONT_INTPND            (1 << 13)
> > +#define IF_MCONT_UMASK             (1 << 12)
> > +#define IF_MCONT_TXIE              (1 << 11)
> > +#define IF_MCONT_RXIE              (1 << 10)
> > +#define IF_MCONT_RMTEN             (1 << 9)
> > +#define IF_MCONT_TXRQST            (1 << 8)
> > +#define IF_MCONT_EOB               (1 << 7)
> > +
> > +/*
> > + * 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_NEXT_MSG_OBJ_MASK    (C_CAN_MSG_OBJ_TX_NUM - 1)
> > +#define RECEIVE_OBJECT_BITS        0x0000ffff
> > +
> > +/* status interrupt */
> > +#define STATUS_INTERRUPT   0x8000
> > +
> > +/* 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_a1;
> > +   u16 data_a2;
> > +   u16 data_b1;
> > +   u16 data_b2;
>
> The later code _mighy_ be easier to read if you define data as an array
> of u16, but let's see...
>
> > +   u16 _reserved[13];
> > +};
> > +
> > +/* c_can hardware registers */
> > +struct c_can_regs {
> > +   u16 control;
> > +   u16 status;
> > +   u16 error_counter;
> > +   u16 btr;
> > +   u16 ir;
> > +   u16 test;
> > +   u16 brp_ext;
> > +   u16 _reserved1;
> > +   struct c_can_if_regs ifreg[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 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
>                            ^
> please add a ","

Oops. Will be done in V3.

> > +};
> > +
> > +enum c_can_interrupt_mode {
> > +   ENABLE_MODULE_INTERRUPT = 0,
> > +   DISABLE_MODULE_INTERRUPT,
> > +   ENABLE_ALL_INTERRUPTS,
> > +   DISABLE_ALL_INTERRUPTS
> same here

Ditto.

> > +};
> > +
> > +/* 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 *reg_base;
> > +   unsigned long irq_flags; /* for request_irq() */
> > +   unsigned int tx_next;
> > +   unsigned int tx_echo;
> > +   struct clk *clk;
> > +};
> > +
> > +static struct can_bittiming_const c_can_bittiming_const = {
> > +   .name = DRV_NAME,
>
> use KBUILD_MODNAME here

OK, will be done in V3.

> > +   .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;
> > +}
> > +
> > +/* 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.
> > + */
>
> /*
>  * this is the preferred multi-line comment style,
>  * please adjust
>  */

Ok.

> > +static u16 c_can_read_reg_aligned_to_16bit(void *reg) {
> > +   return readw(reg);
> > +}
> > +
> > +static void c_can_write_reg_aligned_to_16bit(void *reg, u16 val) {
> > +   writew(val, reg);
> > +}
> > +
> > +static u16 c_can_read_reg_aligned_to_32bit(struct c_can_priv *priv,
> > +void *reg) {
> > +   return readw(reg + (u32)reg - (u32)priv->reg_base);
>
> as Wolfgang said not 64 bit safe.....what about casting the reg_base to
> void __iomem *?

As Wolfgang mentioned do you agree to use long here?

> > +}
> > +
> > +static void c_can_write_reg_aligned_to_32bit(struct c_can_priv
> *priv,
> > +                                   void *reg, u16 val)
> > +{
> > +   writew(val, reg + (u32)reg - (u32)priv->reg_base); }
> > +
> > +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 inline int c_can_configure_interrupts(struct c_can_priv
> *priv,
> > +                                   enum c_can_interrupt_mode intr_mode) {
> > +   unsigned int cntrl_save = priv->read_reg(priv,
> > +                                           &priv->reg_base->control);
> > +
> > +   switch (intr_mode) {
> > +   case ENABLE_MODULE_INTERRUPT:
> > +           cntrl_save |= CONTROL_IE;
> > +           break;
> > +   case DISABLE_MODULE_INTERRUPT:
> > +           cntrl_save &= ~CONTROL_IE;
> > +           break;
> > +   case ENABLE_ALL_INTERRUPTS:
> > +           cntrl_save |= (CONTROL_SIE | CONTROL_EIE | CONTROL_IE);
> > +           break;
> > +   case DISABLE_ALL_INTERRUPTS:
> > +           cntrl_save &= ~(CONTROL_EIE | CONTROL_IE | CONTROL_SIE);
> > +           break;
> > +   default:
> > +           return -EOPNOTSUPP;
> > +   }
> > +
> > +   priv->write_reg(priv, &priv->reg_base->control, cntrl_save);
> > +
> > +   return 0;
> > +}
> > +
> > +static inline int c_can_object_get(struct net_device *dev,
> > +                                   int iface, int objno, int mask)
> > +{
> > +   struct c_can_priv *priv = netdev_priv(dev);
> > +   int timeout = (6 / priv->can.clock.freq);
> > +
> > +   priv->write_reg(priv, &priv->reg_base->ifreg[iface].com_mask,
> > +                   IFX_WRITE_LOW_16BIT(mask));
> > +   priv->write_reg(priv, &priv->reg_base->ifreg[iface].com_reg,
> > +                   IFX_WRITE_LOW_16BIT(objno + 1));
> > +
> > +   /* 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. The delay accounts for the same
> > +    */
> > +   udelay(timeout);
> > +   if ((priv->read_reg(priv, &priv->reg_base->ifreg[iface].com_reg))
> &
> > +                   IF_COMR_BUSY) {
> > +           dev_info(dev->dev.parent, "timed out in object get\n");
> > +           return -ETIMEDOUT;
> > +   }
> > +
> > +   return 0;
> > +}
> > +
> > +static inline int c_can_object_put(struct net_device *dev,
> > +                                   int iface, int objno, int mask)
> > +{
> > +   struct c_can_priv *priv = netdev_priv(dev);
> > +   int timeout = (6 / priv->can.clock.freq);
> > +
> > +   priv->write_reg(priv, &priv->reg_base->ifreg[iface].com_mask,
> > +                   (IF_COMM_WR | IFX_WRITE_LOW_16BIT(mask)));
> > +   priv->write_reg(priv, &priv->reg_base->ifreg[iface].com_reg,
> > +                   IFX_WRITE_LOW_16BIT(objno + 1));
> > +
> > +   /* 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. The delay accounts for the same
> > +    */
> > +   udelay(timeout);
> > +   if ((priv->read_reg(priv, &priv->reg_base->ifreg[iface].com_reg))
> &
> > +                   IF_COMR_BUSY) {
> > +           dev_info(dev->dev.parent, "timed out in object put\n");
> > +           return -ETIMEDOUT;
> > +   }
> > +
> > +   return 0;
> > +}
> > +
> > +int c_can_write_msg_object(struct net_device *dev,
> > +                   int iface, struct can_frame *frame, int objno) {
> > +   u16 flags = 0;
> > +   unsigned int id;
> > +   struct c_can_priv *priv = netdev_priv(dev);
> > +
> > +   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);
> > +
> > +   if (!(frame->can_id & CAN_RTR_FLAG))
> > +           flags |= IF_ARB_TRANSMIT;
> > +
> > +   flags |= IF_ARB_MSGVAL;
> > +
> > +   priv->write_reg(priv, &priv->reg_base->ifreg[iface].arb1,
> > +                           IFX_WRITE_LOW_16BIT(id));
> > +   priv->write_reg(priv, &priv->reg_base->ifreg[iface].arb2, flags |
> > +                           IFX_WRITE_HIGH_16BIT(id));
> > +
> > +   priv->write_reg(priv, &priv->reg_base->ifreg[iface].data_a1,
> > +                   (*(u16 *)(frame->data)));
> > +   priv->write_reg(priv, &priv->reg_base->ifreg[iface].data_a2,
> > +                   (*(u32 *)(frame->data)) >> 16);
> > +
> > +   if (frame->can_dlc > 4) {
> > +           priv->write_reg(priv, &priv->reg_base-
> >ifreg[iface].data_b1,
> > +                   (*(u16 *)(frame->data + 4)));
> > +           priv->write_reg(priv, &priv->reg_base-
> >ifreg[iface].data_b2,
> > +                   (*(u32 *)(frame->data + 4)) >> 16);
> > +   } else
> > +           *(u32 *)(frame->data + 4) = 0;
>
> look at the pch can driver, it uses an array for ifreg->data and is
> endianess safe.

I agree. Will use the same in V3.

> > +
> > +   return frame->can_dlc;
> > +}
> > +
> > +static int c_can_read_msg_object(struct net_device *dev, int iface,
> > +int objno) {
> > +   u16 flags;
> > +   int ctrl;
> > +   unsigned int val, data;
> > +   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;
> > +   }
> > +
> > +   val = c_can_object_get(dev, iface, objno, IF_COMM_ALL &
> > +                                           ~IF_COMM_TXRQST);
> > +   if (val < 0)
> > +           return val;
> > +
> > +   ctrl = priv->read_reg(priv, &priv->reg_base-
> >ifreg[iface].msg_cntrl);
> > +   if (ctrl & IF_MCONT_MSGLST) {
> > +           stats->rx_errors++;
> > +           dev_info(dev->dev.parent, "msg lost in buffer %d\n",
> objno);
> > +   }
> > +
> > +   frame->can_dlc = get_can_dlc(ctrl & 0x0F);
> > +   data = priv->read_reg(priv, &priv->reg_base-
> >ifreg[iface].data_a1) |
> > +           (priv->read_reg(priv, &priv->reg_base-
> >ifreg[iface].data_a2) <<
> > +                   16);
> > +   *(u32 *)(frame->data) = data;
> > +   if (frame->can_dlc > 4) {
> > +           data = priv->read_reg(priv,
> > +                           &priv->reg_base->ifreg[iface].data_b1) |
> > +                   (priv->read_reg(priv,
> > +                           &priv->reg_base->ifreg[iface].data_b2) <<
> > +                           16);
> > +           *(u32 *)(frame->data + 4) = data;
> > +   } else
> > +           *(u32 *)(frame->data + 4) = 0;
>
> dito

Ditto.

> > +
> > +   flags = priv->read_reg(priv, &priv->reg_base-
> >ifreg[iface].arb2);
> > +   val = priv->read_reg(priv, &priv->reg_base->ifreg[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;
> > +
> > +   priv->write_reg(priv, &priv->reg_base->ifreg[iface].msg_cntrl,
> ctrl &
> > +                   ~(IF_MCONT_MSGLST | IF_MCONT_INTPND |
> IF_MCONT_NEWDAT));
> > +
> > +   val = c_can_object_put(dev, iface, objno, IF_COMM_CONTROL);
> > +   if (val < 0)
> > +           return val;
> > +
> > +   netif_receive_skb(skb);
> > +
> > +   stats->rx_packets++;
> > +   stats->rx_bytes += frame->can_dlc;
> > +
> > +   return 0;
> > +}
> > +
> > +static int c_can_setup_receive_object(struct net_device *dev, int
> iface,
> > +                                   int objno, unsigned int mask,
> > +                                   unsigned int id, unsigned int mcont) {
> > +   int ret;
> > +   struct c_can_priv *priv = netdev_priv(dev);
> > +
> > +   priv->write_reg(priv, &priv->reg_base->ifreg[iface].mask1,
> > +                   IFX_WRITE_LOW_16BIT(mask));
> > +   priv->write_reg(priv, &priv->reg_base->ifreg[iface].mask2,
> > +                   IFX_WRITE_HIGH_16BIT(mask));
> > +
> > +   priv->write_reg(priv, &priv->reg_base->ifreg[iface].arb1,
> > +                   IFX_WRITE_LOW_16BIT(id));
> > +   priv->write_reg(priv, &priv->reg_base->ifreg[iface].arb2,
> > +                   (IF_ARB_MSGVAL | IFX_WRITE_HIGH_16BIT(id)));
> > +
> > +   priv->write_reg(priv, &priv->reg_base->ifreg[iface].msg_cntrl,
> mcont);
> > +   ret = c_can_object_put(dev, iface, objno, IF_COMM_ALL &
> > +                                           ~IF_COMM_TXRQST);
> > +   if (ret < 0)
> > +           return ret;
> > +
> > +   dev_dbg(dev->dev.parent, "obj no:%d, msgval:0x%08x\n", objno,
> > +                   c_can_read_reg32(priv, &priv->reg_base->msgval1));
> > +
> > +   return 0;
> > +}
> > +
> > +static int c_can_inval_msg_object(struct net_device *dev, int iface,
> > +int objno) {
> > +   int ret;
> > +   struct c_can_priv *priv = netdev_priv(dev);
> > +
> > +   priv->write_reg(priv, &priv->reg_base->ifreg[iface].arb1, 0);
> > +   priv->write_reg(priv, &priv->reg_base->ifreg[iface].arb2, 0);
> > +   priv->write_reg(priv, &priv->reg_base->ifreg[iface].msg_cntrl,
> 0);
> > +
> > +   ret = c_can_object_put(dev, iface, objno,
> > +                           IF_COMM_ARB | IF_COMM_CONTROL);
> > +   if (ret < 0)
> > +           return ret;
> > +
> > +   dev_dbg(dev->dev.parent, "obj no:%d, msgval:0x%08x\n", objno,
> > +                   c_can_read_reg32(priv, &priv->reg_base->msgval1));
> > +
> > +   return 0;
> > +}
> > +
> > +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->reg_base->ifreg[0].msg_cntrl,
> > +                   IF_MCONT_TXIE | IF_MCONT_TXRQST | IF_MCONT_EOB |
> > +                   (val & 0xf));
> > +   val = c_can_object_put(dev, 0, msg_obj_no, IF_COMM_ALL);
> > +   if (val < 0)
> > +           return val;
> > +
> > +   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_dbg(dev->dev.parent,
> > +                   "brp = %d, brpe = %d, sjw = %d, seg1 = %d, seg2 =
> %d\n",
> > +                   brp, brpe, sjw, tseg1, tseg2);
> > +   dev_dbg(dev->dev.parent, "setting BTR to %04x\n", reg_btr);
> > +   dev_dbg(dev->dev.parent, "setting BRPE to %04x\n", reg_brpe);
> > +
> > +   ctrl_save = priv->read_reg(priv, &priv->reg_base->control);
> > +   priv->write_reg(priv, &priv->reg_base->control,
> > +                   ctrl_save | CONTROL_CCE | CONTROL_INIT);
> > +   priv->write_reg(priv, &priv->reg_base->btr, reg_btr);
> > +   priv->write_reg(priv, &priv->reg_base->brp_ext, reg_brpe);
> > +   priv->write_reg(priv, &priv->reg_base->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 int 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);
> > +   return 0;
> > +}
> > +
> > +/*
> > + * Configure C_CAN chip:
> > + * - enable/disable auto-retransmission
> > + * - set operating mode
> > + * - configure message objects
> > + */
> > +static int 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->reg_base->control,
> > +                           CONTROL_DISABLE_AR);
> > +   else
> > +           /* enable automatic retransmission */
> > +           priv->write_reg(priv, &priv->reg_base->control,
> > +                           CONTROL_ENABLE_AR);
> > +
> > +   if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK) {
> > +           /* loopback mode : useful for self-test function */
> > +           priv->write_reg(priv, &priv->reg_base->control,
> (CONTROL_EIE |
> > +                           CONTROL_SIE | CONTROL_IE | CONTROL_TEST));
> > +           priv->write_reg(priv, &priv->reg_base->test, TEST_LBACK);
> > +   } else if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY) {
> > +           /* silent mode : bus-monitoring mode */
> > +           priv->write_reg(priv, &priv->reg_base->control,
> (CONTROL_EIE |
> > +                           CONTROL_SIE | CONTROL_IE | CONTROL_TEST));
> > +           priv->write_reg(priv, &priv->reg_base->test, TEST_SILENT);
> > +   } else if (priv->can.ctrlmode & (CAN_CTRLMODE_LISTENONLY &
> > +                                   CAN_CTRLMODE_LOOPBACK)) {
> > +           /* loopback + silent mode : useful for hot self-test */
> > +           priv->write_reg(priv, &priv->reg_base->control,
> (CONTROL_EIE |
> > +                           CONTROL_SIE | CONTROL_IE | CONTROL_TEST));
> > +           priv->write_reg(priv, &priv->reg_base->test,
> > +                           (TEST_LBACK | TEST_SILENT));
> > +   } else
> > +           /* normal mode*/
> > +           priv->write_reg(priv, &priv->reg_base->control,
> > +                           (CONTROL_EIE | CONTROL_SIE | CONTROL_IE));
> > +
> > +   /* configure message objects */
> > +   c_can_configure_msg_objects(dev);
> > +
> > +   return 0;
> > +}
> > +
> > +static int c_can_start(struct net_device *dev) {
> > +   int err;
> > +   struct c_can_priv *priv = netdev_priv(dev);
> > +
> > +   /* enable status change, error and module interrupts */
> > +   c_can_configure_interrupts(priv, ENABLE_ALL_INTERRUPTS);
> > +
> > +   /* basic c_can configuration */
> > +   err = c_can_chip_config(dev);
> > +   if (err)
> > +           return err;
> > +
> > +   priv->can.state = CAN_STATE_ERROR_ACTIVE;
> > +
> > +   /* reset tx helper pointers */
> > +   priv->tx_next = priv->tx_echo = 0;
> > +
> > +   return 0;
> > +}
> > +
> > +static int c_can_stop(struct net_device *dev) {
> > +   struct c_can_priv *priv = netdev_priv(dev);
> > +
> > +   /* disable all interrupts */
> > +   c_can_configure_interrupts(priv, DISABLE_ALL_INTERRUPTS);
> > +
> > +   /* set the state as STOPPED */
> > +   priv->can.state = CAN_STATE_STOPPED;
> > +
> > +   return 0;
> > +}
> > +
> > +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);
> > +           dev_info(dev->dev.parent,
> > +                           "c_can CAN_MODE_START requested\n");
> > +           break;
> > +   default:
> > +           return -EOPNOTSUPP;
> > +   }
> > +
> > +   return 0;
> > +}
> > +
> > +static int c_can_get_state(const struct net_device *dev,
> > +                           enum can_state *state)
> > +{
> > +   struct c_can_priv *priv = netdev_priv(dev);
> > +
> > +   *state = priv->can.state;
> > +
> > +   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->reg_base-
> >error_counter);
> > +   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->reg_base->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->reg_base->ifreg[0].msg_cntrl)
> > +                                   & 0xF;
> > +                   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);
> > +}
> > +
> > +/*
> > + * c_can_do_rx_poll - read multiple CAN messages from message
> objects
> > +*/ static int c_can_do_rx_poll(struct net_device *dev, int quota) {
> > +   u32 num_rx_pkts = 0;
> > +   unsigned int msg_obj;
> > +   struct c_can_priv *priv = netdev_priv(dev);
> > +   u32 val = c_can_read_reg32(priv, &priv->reg_base->newdat1);
> > +
> > +   while (val & RECEIVE_OBJECT_BITS) {
> > +           for (msg_obj = C_CAN_MSG_OBJ_RX_FIRST;
> > +                           msg_obj <= C_CAN_MSG_OBJ_RX_LAST; msg_obj++) {
> > +                   if (val & (1 << msg_obj)) {
> > +                           c_can_read_msg_object(dev, 0, msg_obj);
> > +                           num_rx_pkts++;
> > +                           quota--;
> > +                   }
> > +           }
> > +
> > +           val = c_can_read_reg32(priv, &priv->reg_base->newdat1);
> > +   }
> > +
> > +   return num_rx_pkts;
> > +}
> > +
> > +static int c_can_err(struct net_device *dev,
> > +                           enum c_can_bus_error_types error_type,
> > +                           int 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->reg_base-
> >error_counter);
> > +   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_configure_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
> > +    */
> > +   if (lec_type) {
> > +           /* 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;
> > +
> > +           if (lec_type & LEC_STUFF_ERROR) {
> > +                   dev_info(dev->dev.parent, "stuff error\n");
> > +                   cf->data[2] |= CAN_ERR_PROT_STUFF;
> > +           }
> > +           if (lec_type & LEC_FORM_ERROR) {
> > +                   dev_info(dev->dev.parent, "form error\n");
> > +                   cf->data[2] |= CAN_ERR_PROT_FORM;
> > +           }
> > +           if (lec_type & LEC_ACK_ERROR) {
> > +                   dev_info(dev->dev.parent, "ack error\n");
> > +                   cf->data[2] |= (CAN_ERR_PROT_LOC_ACK |
> > +                                   CAN_ERR_PROT_LOC_ACK_DEL);
> > +           }
> > +           if (lec_type & LEC_BIT1_ERROR) {
> > +                   dev_info(dev->dev.parent, "bit1 error\n");
> > +                   cf->data[2] |= CAN_ERR_PROT_BIT1;
> > +           }
> > +           if (lec_type & LEC_BIT0_ERROR) {
> > +                   dev_info(dev->dev.parent, "bit0 error\n");
> > +                   cf->data[2] |= CAN_ERR_PROT_BIT0;
> > +           }
> > +           if (lec_type & LEC_CRC_ERROR) {
> > +                   dev_info(dev->dev.parent, "CRC error\n");
> > +                   cf->data[2] |= (CAN_ERR_PROT_LOC_CRC_SEQ |
> > +                                   CAN_ERR_PROT_LOC_CRC_DEL);
> > +           }
> > +   }
> > +
> > +   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->reg_base->ir);
> > +
> > +   /* status events have the highest priority */
> > +   if (irqstatus == STATUS_INTERRUPT) {
> > +           priv->current_status = priv->read_reg(priv,
> > +                                   &priv->reg_base->status);
> > +
> > +           /* handle Tx/Rx events */
> > +           if (priv->current_status & STATUS_TXOK)
> > +                   priv->write_reg(priv, &priv->reg_base->status,
> > +                                   (priv->current_status & ~STATUS_TXOK));
> > +
> > +           if (priv->current_status & STATUS_RXOK)
> > +                   priv->write_reg(priv, &priv->reg_base->status,
> > +                                   (priv->current_status & ~STATUS_RXOK));
> > +
> > +           /* handle bus error events */
> > +           if (priv->current_status & STATUS_EWARN) {
> > +                   dev_info(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_info(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_info(dev->dev.parent,
> > +                                   "entered bus off state\n");
> > +                   error_type = C_CAN_BUS_OFF;
> > +           }
> > +           if (priv->current_status & STATUS_LEC_MASK)
> > +                   lec_type = (priv->current_status & STATUS_LEC_MASK);
> > +
> > +           /* handle bus recovery events */
> > +           if ((!(priv->current_status & STATUS_EPASS)) &&
> > +                           (priv->last_status & STATUS_EPASS)) {
> > +                   dev_info(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_info(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 */
> > +           if (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));
> > +           quota--;
> > +   } 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_configure_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_configure_interrupts(priv, DISABLE_ALL_INTERRUPTS);
> > +   napi_schedule(&priv->napi);
> > +
> > +   return IRQ_HANDLED;
> > +}
> > +
> > +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,
> > +                           (void *)dev);
> > +   if (err < 0) {
> > +           dev_err(dev->dev.parent, "failed to attach interrupt\n");
> > +           goto exit_irq_fail;
> > +   }
> > +
> > +   /* start the c_can controller */
> > +   err = c_can_start(dev);
> > +   if (err)
> > +           goto exit_start_fail;
> > +   napi_enable(&priv->napi);
> > +
> > +   netif_start_queue(dev);
> > +
> > +   return 0;
> > +
> > +exit_start_fail:
> > +   free_irq(dev->irq, dev);
> > +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;
> > +}
> > +
> > +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,
> > +};
> > +
> > +static int c_can_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),
> DRV_NAME)) {
> > +           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_candev(sizeof(struct c_can_priv),
> C_CAN_MSG_OBJ_TX_NUM);
> > +   if (!dev) {
> > +           ret = -ENOMEM;
> > +           goto exit_iounmap;
> > +   }
> > +
> > +   priv = netdev_priv(dev);
> > +
> > +   priv->irq_flags = irq->flags;
> > +   priv->reg_base = addr;
> > +   priv->can.clock.freq = clk_get_rate(clk);
> > +   priv->clk = clk;
> > +
> > +   switch (mem->flags & IORESOURCE_MEM_TYPE_MASK) {
> > +   case IORESOURCE_MEM_32BIT:
> > +           priv->read_reg = c_can_read_reg_aligned_to_32bit;
> > +           priv->write_reg = c_can_write_reg_aligned_to_32bit;
> > +           break;
> > +   case IORESOURCE_MEM_16BIT:
> > +   default:
> > +           priv->read_reg = c_can_read_reg_aligned_to_16bit;
> > +           priv->write_reg = c_can_write_reg_aligned_to_16bit;
> > +           break;
> > +   }
> > +
> > +   priv->dev = dev;
> > +   priv->can.bittiming_const = &c_can_bittiming_const;
> > +   priv->can.do_set_bittiming = c_can_set_bittiming;
> > +   priv->can.do_get_state = c_can_get_state;
> > +   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;
> > +
> > +   netif_napi_add(dev, &priv->napi, c_can_poll, C_CAN_NAPI_WEIGHT);
> > +
> > +   dev->irq = irq->start;
> > +   dev->flags |= IFF_ECHO; /* we support local echo */
> > +   dev->netdev_ops = &c_can_netdev_ops;
> > +   platform_set_drvdata(pdev, dev);
> > +   SET_NETDEV_DEV(dev, &pdev->dev);
> > +
> > +   ret = register_candev(dev);
> > +   if (ret) {
> > +           dev_err(&pdev->dev, "registering %s failed (err=%d)\n",
> > +                   DRV_NAME, ret);
> > +           goto exit_free_device;
> > +   }
> > +
> > +   dev_info(&pdev->dev, "%s device registered (reg_base=%p,
> irq=%d)\n",
> > +            DRV_NAME, priv->reg_base, dev->irq);
> > +   return 0;
> > +
> > +exit_free_device:
> > +   platform_set_drvdata(pdev, NULL);
> > +   free_candev(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 c_can_remove(struct platform_device *pdev) {
> > +   struct net_device *dev = platform_get_drvdata(pdev);
> > +   struct c_can_priv *priv = netdev_priv(dev);
> > +   struct resource *mem;
> > +
> > +   /* disable all interrupts */
> > +   c_can_configure_interrupts(priv, DISABLE_ALL_INTERRUPTS);
> > +
> > +   unregister_candev(dev);
> > +   platform_set_drvdata(pdev, NULL);
> > +
> > +   free_candev(dev);
> > +   iounmap(priv->reg_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 c_can_driver = {
> > +   .driver         = {
> > +           .name   = DRV_NAME,
> > +           .owner = THIS_MODULE,
> > +   },
> > +   .probe          = c_can_probe,
> > +   .remove         = c_can_remove,
> > +};
> > +
> > +static int __init c_can_init(void)
> > +{
> > +   return platform_driver_register(&c_can_driver);
> > +}
> > +module_init(c_can_init);
> > +
> > +static void __exit c_can_exit(void)
> > +{
> > +   platform_driver_unregister(&c_can_driver);
> > +}
> > +module_exit(c_can_exit);
> > +
> > +MODULE_AUTHOR("Bhupesh Sharma <bhupesh.sharma@...com>");
> > +MODULE_LICENSE("GPL v2"); MODULE_DESCRIPTION("CAN bus driver for
> > +Bosch C_CAN controller");
>
>
> --
> 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   |

Regards,
Bhupesh
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