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Message-ID: <D5ECB3C7A6F99444980976A8C6D896384DEAFA31B6@EAPEX1MAIL1.st.com>
Date: Wed, 12 Jan 2011 16:51:24 +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>,
David Miller <davem@...emloft.net>,
Wolfgang Grandegger <wg@...ndegger.com>
Subject: RE: [PATCH net-next-2.6 v4 1/1] can: c_can: Added support for Bosch
C_CAN controller
Hi Marc,
Thanks for your review.
Please see my comments inline:
> -----Original Message-----
> From: Marc Kleine-Budde [mailto:mkl@...gutronix.de]
> 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,".
ACK.
> >
> > 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.
Ok.
> >
> > Signed-off-by: Bhupesh Sharma <bhupesh.sharma@...com>
> > ---
> > 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 <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>
> > + *
> > + * 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].
I am not sure that C_CAN will be effected as per the at91 driver changes.
In C_CAN, messages numbers are allowed only from 0x01 to 0x20. Message object
number 0 is not allowed. Internally obj-put and obj-get routines increment the
message number by 1.
> > + * Copyright
> > + * (C) 2007 by Hans J. Koch <hjk@...utronix.de>
> ^^^^^^^^^^^^^^^^^^^
>
> Hans has recently changed his email address, it's "hjk@...sjkoch.de"
Ok :)
> > + * (C) 2008, 2009 by Marc Kleine-Budde <kernel@...gutronix.de>
> > + *
> > + * 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.
Ok.
> > + 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?
I will explore the possibility of using the same.
But, IMHO this logic seems much easier to understand than a
*for* loop with bulky *find_next_bit* call.
> > + 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.
Could you please send me a reference URL for the same.
As the pch_can driver code in David's net-next and net tree has almost
similar implementation to the c_can driver.
Or, am I missing something here?
> > +
> > +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)
Ok.
But Wolfgang also suggested to use the *priv* member inside c_can_priv struct
for board specific details. In my c_can platform driver I use it to
store the *clk* variable. Do I need to change that as well?
> > +{
> > + 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 <bhupesh.sharma@...com>");
> > +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 <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>
> > + *
> > + * TX and RX NAPI implementation has been borrowed from at91 CAN
> > +driver
> > + * written by:
> > + * Copyright
> > + * (C) 2007 by Hans J. Koch <hjk@...utronix.de>
> > + * (C) 2008, 2009 by Marc Kleine-Budde <kernel@...gutronix.de>
>
> IMHO you can drop the at91 copyright reference here.
Ok.
> > + *
> > + * 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
Please see above.
> > +};
> > +
> > +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 <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>
> > + *
> > + * 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 <bhupesh.sharma@...com>");
> > +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 |
Regards,
Bhupesh
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